3505 lines
115 KiB
C
3505 lines
115 KiB
C
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#if defined(SQLITE_ENABLE_SESSION) && defined(SQLITE_ENABLE_PREUPDATE_HOOK)
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#include "sqlite3session.h"
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#include <assert.h>
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#include <string.h>
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#ifndef SQLITE_AMALGAMATION
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# include "sqliteInt.h"
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# include "vdbeInt.h"
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#endif
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typedef struct SessionTable SessionTable;
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typedef struct SessionChange SessionChange;
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typedef struct SessionBuffer SessionBuffer;
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/*
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** Session handle structure.
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*/
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struct sqlite3_session {
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sqlite3 *db; /* Database handle session is attached to */
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char *zDb; /* Name of database session is attached to */
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int bEnable; /* True if currently recording */
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int bIndirect; /* True if all changes are indirect */
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int bAutoAttach; /* True to auto-attach tables */
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int rc; /* Non-zero if an error has occurred */
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void *pFilterCtx; /* First argument to pass to xTableFilter */
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int (*xTableFilter)(void *pCtx, const char *zTab);
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sqlite3_session *pNext; /* Next session object on same db. */
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SessionTable *pTable; /* List of attached tables */
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};
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/*
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** Structure for changeset iterators.
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*/
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struct sqlite3_changeset_iter {
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u8 *aChangeset; /* Pointer to buffer containing changeset */
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int nChangeset; /* Number of bytes in aChangeset */
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int bPatchset; /* True if this is a patchset */
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u8 *pNext; /* Pointer to next change within aChangeset */
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int rc; /* Iterator error code */
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sqlite3_stmt *pConflict; /* Points to conflicting row, if any */
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char *zTab; /* Current table */
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int nCol; /* Number of columns in zTab */
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int op; /* Current operation */
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int bIndirect; /* True if current change was indirect */
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u8 *abPK; /* Primary key array */
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sqlite3_value **apValue; /* old.* and new.* values */
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};
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/*
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** Each session object maintains a set of the following structures, one
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** for each table the session object is monitoring. The structures are
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** stored in a linked list starting at sqlite3_session.pTable.
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**
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** The keys of the SessionTable.aChange[] hash table are all rows that have
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** been modified in any way since the session object was attached to the
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** table.
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**
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** The data associated with each hash-table entry is a structure containing
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** a subset of the initial values that the modified row contained at the
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** start of the session. Or no initial values if the row was inserted.
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*/
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struct SessionTable {
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SessionTable *pNext;
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char *zName; /* Local name of table */
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int nCol; /* Number of columns in table zName */
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const char **azCol; /* Column names */
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u8 *abPK; /* Array of primary key flags */
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int nEntry; /* Total number of entries in hash table */
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int nChange; /* Size of apChange[] array */
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SessionChange **apChange; /* Hash table buckets */
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};
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/*
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** RECORD FORMAT:
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**
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** The following record format is similar to (but not compatible with) that
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** used in SQLite database files. This format is used as part of the
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** change-set binary format, and so must be architecture independent.
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**
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** Unlike the SQLite database record format, each field is self-contained -
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** there is no separation of header and data. Each field begins with a
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** single byte describing its type, as follows:
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**
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** 0x00: Undefined value.
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** 0x01: Integer value.
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** 0x02: Real value.
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** 0x03: Text value.
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** 0x04: Blob value.
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** 0x05: SQL NULL value.
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**
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** Note that the above match the definitions of SQLITE_INTEGER, SQLITE_TEXT
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** and so on in sqlite3.h. For undefined and NULL values, the field consists
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** only of the single type byte. For other types of values, the type byte
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** is followed by:
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**
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** Text values:
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** A varint containing the number of bytes in the value (encoded using
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** UTF-8). Followed by a buffer containing the UTF-8 representation
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** of the text value. There is no nul terminator.
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**
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** Blob values:
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** A varint containing the number of bytes in the value, followed by
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** a buffer containing the value itself.
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**
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** Integer values:
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** An 8-byte big-endian integer value.
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**
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** Real values:
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** An 8-byte big-endian IEEE 754-2008 real value.
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**
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** Varint values are encoded in the same way as varints in the SQLite
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** record format.
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**
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** CHANGESET FORMAT:
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**
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** A changeset is a collection of DELETE, UPDATE and INSERT operations on
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** one or more tables. Operations on a single table are grouped together,
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** but may occur in any order (i.e. deletes, updates and inserts are all
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** mixed together).
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**
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** Each group of changes begins with a table header:
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**
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** 1 byte: Constant 0x54 (capital 'T')
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** Varint: Big-endian integer set to the number of columns in the table.
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** nCol bytes: 0x01 for PK columns, 0x00 otherwise.
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** N bytes: Unqualified table name (encoded using UTF-8). Nul-terminated.
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**
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** Followed by one or more changes to the table.
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**
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** 1 byte: Either SQLITE_INSERT, UPDATE or DELETE.
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** 1 byte: The "indirect-change" flag.
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** old.* record: (delete and update only)
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** new.* record: (insert and update only)
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**
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** PATCHSET FORMAT:
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**
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** A patchset is also a collection of changes. It is similar to a changeset,
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** but omits those fields that are not useful if no conflict resolution
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** is required when applying the changeset.
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**
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** Each group of changes begins with a table header:
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**
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** 1 byte: Constant 0x50 (capital 'P')
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** Varint: Big-endian integer set to the number of columns in the table.
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** nCol bytes: 0x01 for PK columns, 0x00 otherwise.
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** N bytes: Unqualified table name (encoded using UTF-8). Nul-terminated.
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**
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** Followed by one or more changes to the table.
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**
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** 1 byte: Either SQLITE_INSERT, UPDATE or DELETE.
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** 1 byte: The "indirect-change" flag.
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** single record: (PK fields for DELETE, or full record for INSERT/UPDATE).
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*/
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/*
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** For each row modified during a session, there exists a single instance of
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** this structure stored in a SessionTable.aChange[] hash table.
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*/
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struct SessionChange {
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int op; /* One of UPDATE, DELETE, INSERT */
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int bIndirect; /* True if this change is "indirect" */
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int nRecord; /* Number of bytes in buffer aRecord[] */
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u8 *aRecord; /* Buffer containing old.* record */
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SessionChange *pNext; /* For hash-table collisions */
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};
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/*
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** Instances of this structure are used to build strings or binary records.
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*/
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struct SessionBuffer {
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u8 *aBuf; /* Pointer to changeset buffer */
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int nBuf; /* Size of buffer aBuf */
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int nAlloc; /* Size of allocation containing aBuf */
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};
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/*
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** Write a varint with value iVal into the buffer at aBuf. Return the
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** number of bytes written.
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*/
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static int sessionVarintPut(u8 *aBuf, int iVal){
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return putVarint32(aBuf, iVal);
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}
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/*
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** Return the number of bytes required to store value iVal as a varint.
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*/
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static int sessionVarintLen(int iVal){
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return sqlite3VarintLen(iVal);
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}
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/*
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** Read a varint value from aBuf[] into *piVal. Return the number of
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** bytes read.
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*/
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static int sessionVarintGet(u8 *aBuf, int *piVal){
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return getVarint32(aBuf, *piVal);
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}
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/*
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** Read a 64-bit big-endian integer value from buffer aRec[]. Return
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** the value read.
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*/
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static sqlite3_int64 sessionGetI64(u8 *aRec){
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return (((sqlite3_int64)aRec[0]) << 56)
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+ (((sqlite3_int64)aRec[1]) << 48)
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+ (((sqlite3_int64)aRec[2]) << 40)
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+ (((sqlite3_int64)aRec[3]) << 32)
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+ (((sqlite3_int64)aRec[4]) << 24)
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+ (((sqlite3_int64)aRec[5]) << 16)
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+ (((sqlite3_int64)aRec[6]) << 8)
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+ (((sqlite3_int64)aRec[7]) << 0);
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}
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/*
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** Write a 64-bit big-endian integer value to the buffer aBuf[].
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*/
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static void sessionPutI64(u8 *aBuf, sqlite3_int64 i){
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aBuf[0] = (i>>56) & 0xFF;
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aBuf[1] = (i>>48) & 0xFF;
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aBuf[2] = (i>>40) & 0xFF;
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aBuf[3] = (i>>32) & 0xFF;
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aBuf[4] = (i>>24) & 0xFF;
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aBuf[5] = (i>>16) & 0xFF;
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aBuf[6] = (i>> 8) & 0xFF;
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aBuf[7] = (i>> 0) & 0xFF;
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}
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/*
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** This function is used to serialize the contents of value pValue (see
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** comment titled "RECORD FORMAT" above).
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**
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** If it is non-NULL, the serialized form of the value is written to
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** buffer aBuf. *pnWrite is set to the number of bytes written before
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** returning. Or, if aBuf is NULL, the only thing this function does is
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** set *pnWrite.
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**
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** If no error occurs, SQLITE_OK is returned. Or, if an OOM error occurs
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** within a call to sqlite3_value_text() (may fail if the db is utf-16))
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** SQLITE_NOMEM is returned.
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*/
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static int sessionSerializeValue(
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u8 *aBuf, /* If non-NULL, write serialized value here */
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sqlite3_value *pValue, /* Value to serialize */
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int *pnWrite /* IN/OUT: Increment by bytes written */
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){
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int nByte; /* Size of serialized value in bytes */
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if( pValue ){
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int eType; /* Value type (SQLITE_NULL, TEXT etc.) */
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eType = sqlite3_value_type(pValue);
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if( aBuf ) aBuf[0] = eType;
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switch( eType ){
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case SQLITE_NULL:
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nByte = 1;
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break;
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case SQLITE_INTEGER:
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case SQLITE_FLOAT:
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if( aBuf ){
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/* TODO: SQLite does something special to deal with mixed-endian
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** floating point values (e.g. ARM7). This code probably should
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** too. */
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u64 i;
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if( eType==SQLITE_INTEGER ){
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i = (u64)sqlite3_value_int64(pValue);
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}else{
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double r;
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assert( sizeof(double)==8 && sizeof(u64)==8 );
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r = sqlite3_value_double(pValue);
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memcpy(&i, &r, 8);
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}
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sessionPutI64(&aBuf[1], i);
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}
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nByte = 9;
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break;
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default: {
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u8 *z;
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int n;
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int nVarint;
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assert( eType==SQLITE_TEXT || eType==SQLITE_BLOB );
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if( eType==SQLITE_TEXT ){
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z = (u8 *)sqlite3_value_text(pValue);
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}else{
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z = (u8 *)sqlite3_value_blob(pValue);
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}
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if( z==0 ) return SQLITE_NOMEM;
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n = sqlite3_value_bytes(pValue);
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nVarint = sessionVarintLen(n);
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if( aBuf ){
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sessionVarintPut(&aBuf[1], n);
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memcpy(&aBuf[nVarint + 1], eType==SQLITE_TEXT ?
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sqlite3_value_text(pValue) : sqlite3_value_blob(pValue), n
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);
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}
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nByte = 1 + nVarint + n;
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break;
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}
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}
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}else{
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nByte = 1;
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if( aBuf ) aBuf[0] = '\0';
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}
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*pnWrite += nByte;
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return SQLITE_OK;
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}
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/*
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** This macro is used to calculate hash key values for data structures. In
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** order to use this macro, the entire data structure must be represented
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** as a series of unsigned integers. In order to calculate a hash-key value
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** for a data structure represented as three such integers, the macro may
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** then be used as follows:
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**
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** int hash_key_value;
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** hash_key_value = HASH_APPEND(0, <value 1>);
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** hash_key_value = HASH_APPEND(hash_key_value, <value 2>);
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** hash_key_value = HASH_APPEND(hash_key_value, <value 3>);
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**
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** In practice, the data structures this macro is used for are the primary
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** key values of modified rows.
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*/
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#define HASH_APPEND(hash, add) ((hash) << 3) ^ (hash) ^ (unsigned int)(add)
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/*
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** Append the hash of the 64-bit integer passed as the second argument to the
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** hash-key value passed as the first. Return the new hash-key value.
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*/
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static unsigned int sessionHashAppendI64(unsigned int h, i64 i){
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h = HASH_APPEND(h, i & 0xFFFFFFFF);
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return HASH_APPEND(h, (i>>32)&0xFFFFFFFF);
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}
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/*
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** Append the hash of the blob passed via the second and third arguments to
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** the hash-key value passed as the first. Return the new hash-key value.
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*/
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static unsigned int sessionHashAppendBlob(unsigned int h, int n, const u8 *z){
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int i;
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for(i=0; i<n; i++) h = HASH_APPEND(h, z[i]);
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return h;
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}
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/*
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** Append the hash of the data type passed as the second argument to the
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** hash-key value passed as the first. Return the new hash-key value.
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*/
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static unsigned int sessionHashAppendType(unsigned int h, int eType){
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return HASH_APPEND(h, eType);
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}
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/*
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** This function may only be called from within a pre-update callback.
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** It calculates a hash based on the primary key values of the old.* or
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** new.* row currently available and, assuming no error occurs, writes it to
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** *piHash before returning. If the primary key contains one or more NULL
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** values, *pbNullPK is set to true before returning.
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**
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** If an error occurs, an SQLite error code is returned and the final values
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** of *piHash asn *pbNullPK are undefined. Otherwise, SQLITE_OK is returned
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** and the output variables are set as described above.
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*/
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static int sessionPreupdateHash(
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sqlite3 *db, /* Database handle */
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SessionTable *pTab, /* Session table handle */
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int bNew, /* True to hash the new.* PK */
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int *piHash, /* OUT: Hash value */
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int *pbNullPK /* OUT: True if there are NULL values in PK */
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){
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unsigned int h = 0; /* Hash value to return */
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int i; /* Used to iterate through columns */
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assert( *pbNullPK==0 );
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assert( pTab->nCol==sqlite3_preupdate_count(db) );
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for(i=0; i<pTab->nCol; i++){
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if( pTab->abPK[i] ){
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int rc;
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int eType;
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sqlite3_value *pVal;
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if( bNew ){
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rc = sqlite3_preupdate_new(db, i, &pVal);
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}else{
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rc = sqlite3_preupdate_old(db, i, &pVal);
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}
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if( rc!=SQLITE_OK ) return rc;
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eType = sqlite3_value_type(pVal);
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h = sessionHashAppendType(h, eType);
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if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){
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i64 iVal;
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if( eType==SQLITE_INTEGER ){
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iVal = sqlite3_value_int64(pVal);
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}else{
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double rVal = sqlite3_value_double(pVal);
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assert( sizeof(iVal)==8 && sizeof(rVal)==8 );
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memcpy(&iVal, &rVal, 8);
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}
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h = sessionHashAppendI64(h, iVal);
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}else if( eType==SQLITE_TEXT || eType==SQLITE_BLOB ){
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const u8 *z;
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if( eType==SQLITE_TEXT ){
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z = (const u8 *)sqlite3_value_text(pVal);
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}else{
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z = (const u8 *)sqlite3_value_blob(pVal);
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}
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if( !z ) return SQLITE_NOMEM;
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h = sessionHashAppendBlob(h, sqlite3_value_bytes(pVal), z);
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}else{
|
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assert( eType==SQLITE_NULL );
|
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*pbNullPK = 1;
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}
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}
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}
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*piHash = (h % pTab->nChange);
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return SQLITE_OK;
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}
|
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|
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/*
|
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** The buffer that the argument points to contains a serialized SQL value.
|
|
** Return the number of bytes of space occupied by the value (including
|
|
** the type byte).
|
|
*/
|
|
static int sessionSerialLen(u8 *a){
|
|
int e = *a;
|
|
int n;
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if( e==0 ) return 1;
|
|
if( e==SQLITE_NULL ) return 1;
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|
if( e==SQLITE_INTEGER || e==SQLITE_FLOAT ) return 9;
|
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return sessionVarintGet(&a[1], &n) + 1 + n;
|
|
}
|
|
|
|
/*
|
|
** Based on the primary key values stored in change aRecord, calculate a
|
|
** hash key. Assume the has table has nBucket buckets. The hash keys
|
|
** calculated by this function are compatible with those calculated by
|
|
** sessionPreupdateHash().
|
|
**
|
|
** The bPkOnly argument is non-zero if the record at aRecord[] is from
|
|
** a patchset DELETE. In this case the non-PK fields are omitted entirely.
|
|
*/
|
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static unsigned int sessionChangeHash(
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SessionTable *pTab, /* Table handle */
|
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int bPkOnly, /* Record consists of PK fields only */
|
|
u8 *aRecord, /* Change record */
|
|
int nBucket /* Assume this many buckets in hash table */
|
|
){
|
|
unsigned int h = 0; /* Value to return */
|
|
int i; /* Used to iterate through columns */
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u8 *a = aRecord; /* Used to iterate through change record */
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for(i=0; i<pTab->nCol; i++){
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int eType = *a;
|
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int isPK = pTab->abPK[i];
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if( bPkOnly && isPK==0 ) continue;
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|
|
/* It is not possible for eType to be SQLITE_NULL here. The session
|
|
** module does not record changes for rows with NULL values stored in
|
|
** primary key columns. */
|
|
assert( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT
|
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|| eType==SQLITE_TEXT || eType==SQLITE_BLOB
|
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|| eType==SQLITE_NULL || eType==0
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);
|
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assert( !isPK || (eType!=0 && eType!=SQLITE_NULL) );
|
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|
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if( isPK ){
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a++;
|
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h = sessionHashAppendType(h, eType);
|
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if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){
|
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h = sessionHashAppendI64(h, sessionGetI64(a));
|
|
a += 8;
|
|
}else{
|
|
int n;
|
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a += sessionVarintGet(a, &n);
|
|
h = sessionHashAppendBlob(h, n, a);
|
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a += n;
|
|
}
|
|
}else{
|
|
a += sessionSerialLen(a);
|
|
}
|
|
}
|
|
return (h % nBucket);
|
|
}
|
|
|
|
/*
|
|
** Arguments aLeft and aRight are pointers to change records for table pTab.
|
|
** This function returns true if the two records apply to the same row (i.e.
|
|
** have the same values stored in the primary key columns), or false
|
|
** otherwise.
|
|
*/
|
|
static int sessionChangeEqual(
|
|
SessionTable *pTab, /* Table used for PK definition */
|
|
int bLeftPkOnly, /* True if aLeft[] contains PK fields only */
|
|
u8 *aLeft, /* Change record */
|
|
int bRightPkOnly, /* True if aRight[] contains PK fields only */
|
|
u8 *aRight /* Change record */
|
|
){
|
|
u8 *a1 = aLeft; /* Cursor to iterate through aLeft */
|
|
u8 *a2 = aRight; /* Cursor to iterate through aRight */
|
|
int iCol; /* Used to iterate through table columns */
|
|
|
|
for(iCol=0; iCol<pTab->nCol; iCol++){
|
|
int n1 = sessionSerialLen(a1);
|
|
int n2 = sessionSerialLen(a2);
|
|
|
|
if( pTab->abPK[iCol] && (n1!=n2 || memcmp(a1, a2, n1)) ){
|
|
return 0;
|
|
}
|
|
if( pTab->abPK[iCol] || bLeftPkOnly==0 ) a1 += n1;
|
|
if( pTab->abPK[iCol] || bRightPkOnly==0 ) a2 += n2;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
** Arguments aLeft and aRight both point to buffers containing change
|
|
** records with nCol columns. This function "merges" the two records into
|
|
** a single records which is written to the buffer at *paOut. *paOut is
|
|
** then set to point to one byte after the last byte written before
|
|
** returning.
|
|
**
|
|
** The merging of records is done as follows: For each column, if the
|
|
** aRight record contains a value for the column, copy the value from
|
|
** their. Otherwise, if aLeft contains a value, copy it. If neither
|
|
** record contains a value for a given column, then neither does the
|
|
** output record.
|
|
*/
|
|
static void sessionMergeRecord(
|
|
u8 **paOut,
|
|
int nCol,
|
|
u8 *aLeft,
|
|
u8 *aRight
|
|
){
|
|
u8 *a1 = aLeft; /* Cursor used to iterate through aLeft */
|
|
u8 *a2 = aRight; /* Cursor used to iterate through aRight */
|
|
u8 *aOut = *paOut; /* Output cursor */
|
|
int iCol; /* Used to iterate from 0 to nCol */
|
|
|
|
for(iCol=0; iCol<nCol; iCol++){
|
|
int n1 = sessionSerialLen(a1);
|
|
int n2 = sessionSerialLen(a2);
|
|
if( *a2 ){
|
|
memcpy(aOut, a2, n2);
|
|
aOut += n2;
|
|
}else{
|
|
memcpy(aOut, a1, n1);
|
|
aOut += n1;
|
|
}
|
|
a1 += n1;
|
|
a2 += n2;
|
|
}
|
|
|
|
*paOut = aOut;
|
|
}
|
|
|
|
/*
|
|
** This is a helper function used by sessionMergeUpdate().
|
|
**
|
|
** When this function is called, both *paOne and *paTwo point to a value
|
|
** within a change record. Before it returns, both have been advanced so
|
|
** as to point to the next value in the record.
|
|
**
|
|
** If, when this function is called, *paTwo points to a valid value (i.e.
|
|
** *paTwo[0] is not 0x00 - the "no value" placeholder), a copy of the *paOne
|
|
** pointer is returned and *pnVal is set to the number of bytes in the
|
|
** serialized value. Otherwise, a copy of *paOne is returned and *pnVal
|
|
** set to the number of bytes in the value at *paOne. If *paOne points
|
|
** to the "no value" placeholder, *pnVal is set to 1.
|
|
*/
|
|
static u8 *sessionMergeValue(
|
|
u8 **paOne, /* IN/OUT: Left-hand buffer pointer */
|
|
u8 **paTwo, /* IN/OUT: Right-hand buffer pointer */
|
|
int *pnVal /* OUT: Bytes in returned value */
|
|
){
|
|
u8 *a1 = *paOne;
|
|
u8 *a2 = *paTwo;
|
|
u8 *pRet = 0;
|
|
int n1;
|
|
|
|
assert( a1 );
|
|
if( a2 ){
|
|
int n2 = sessionSerialLen(a2);
|
|
if( *a2 ){
|
|
*pnVal = n2;
|
|
pRet = a2;
|
|
}
|
|
*paTwo = &a2[n2];
|
|
}
|
|
|
|
n1 = sessionSerialLen(a1);
|
|
if( pRet==0 ){
|
|
*pnVal = n1;
|
|
pRet = a1;
|
|
}
|
|
*paOne = &a1[n1];
|
|
|
|
return pRet;
|
|
}
|
|
|
|
/*
|
|
** This function is used by changeset_concat() to merge two UPDATE changes
|
|
** on the same row.
|
|
*/
|
|
static int sessionMergeUpdate(
|
|
u8 **paOut, /* IN/OUT: Pointer to output buffer */
|
|
SessionTable *pTab, /* Table change pertains to */
|
|
int bPatchset, /* True if records are patchset records */
|
|
u8 *aOldRecord1, /* old.* record for first change */
|
|
u8 *aOldRecord2, /* old.* record for second change */
|
|
u8 *aNewRecord1, /* new.* record for first change */
|
|
u8 *aNewRecord2 /* new.* record for second change */
|
|
){
|
|
u8 *aOld1 = aOldRecord1;
|
|
u8 *aOld2 = aOldRecord2;
|
|
u8 *aNew1 = aNewRecord1;
|
|
u8 *aNew2 = aNewRecord2;
|
|
|
|
u8 *aOut = *paOut;
|
|
int i;
|
|
|
|
if( bPatchset==0 ){
|
|
int bRequired = 0;
|
|
|
|
assert( aOldRecord1 && aNewRecord1 );
|
|
|
|
/* Write the old.* vector first. */
|
|
for(i=0; i<pTab->nCol; i++){
|
|
int nOld;
|
|
u8 *aOld;
|
|
int nNew;
|
|
u8 *aNew;
|
|
|
|
aOld = sessionMergeValue(&aOld1, &aOld2, &nOld);
|
|
aNew = sessionMergeValue(&aNew1, &aNew2, &nNew);
|
|
if( pTab->abPK[i] || nOld!=nNew || memcmp(aOld, aNew, nNew) ){
|
|
if( pTab->abPK[i]==0 ) bRequired = 1;
|
|
memcpy(aOut, aOld, nOld);
|
|
aOut += nOld;
|
|
}else{
|
|
*(aOut++) = '\0';
|
|
}
|
|
}
|
|
|
|
if( !bRequired ) return 0;
|
|
}
|
|
|
|
/* Write the new.* vector */
|
|
aOld1 = aOldRecord1;
|
|
aOld2 = aOldRecord2;
|
|
aNew1 = aNewRecord1;
|
|
aNew2 = aNewRecord2;
|
|
for(i=0; i<pTab->nCol; i++){
|
|
int nOld;
|
|
u8 *aOld;
|
|
int nNew;
|
|
u8 *aNew;
|
|
|
|
aOld = sessionMergeValue(&aOld1, &aOld2, &nOld);
|
|
aNew = sessionMergeValue(&aNew1, &aNew2, &nNew);
|
|
if( bPatchset==0
|
|
&& (pTab->abPK[i] || (nOld==nNew && 0==memcmp(aOld, aNew, nNew)))
|
|
){
|
|
*(aOut++) = '\0';
|
|
}else{
|
|
memcpy(aOut, aNew, nNew);
|
|
aOut += nNew;
|
|
}
|
|
}
|
|
|
|
*paOut = aOut;
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
** This function is only called from within a pre-update-hook callback.
|
|
** It determines if the current pre-update-hook change affects the same row
|
|
** as the change stored in argument pChange. If so, it returns true. Otherwise
|
|
** if the pre-update-hook does not affect the same row as pChange, it returns
|
|
** false.
|
|
*/
|
|
static int sessionPreupdateEqual(
|
|
sqlite3 *db, /* Database handle */
|
|
SessionTable *pTab, /* Table associated with change */
|
|
SessionChange *pChange, /* Change to compare to */
|
|
int op /* Current pre-update operation */
|
|
){
|
|
int iCol; /* Used to iterate through columns */
|
|
u8 *a = pChange->aRecord; /* Cursor used to scan change record */
|
|
|
|
assert( op==SQLITE_INSERT || op==SQLITE_UPDATE || op==SQLITE_DELETE );
|
|
for(iCol=0; iCol<pTab->nCol; iCol++){
|
|
if( !pTab->abPK[iCol] ){
|
|
a += sessionSerialLen(a);
|
|
}else{
|
|
sqlite3_value *pVal; /* Value returned by preupdate_new/old */
|
|
int rc; /* Error code from preupdate_new/old */
|
|
int eType = *a++; /* Type of value from change record */
|
|
|
|
/* The following calls to preupdate_new() and preupdate_old() can not
|
|
** fail. This is because they cache their return values, and by the
|
|
** time control flows to here they have already been called once from
|
|
** within sessionPreupdateHash(). The first two asserts below verify
|
|
** this (that the method has already been called). */
|
|
if( op==SQLITE_INSERT ){
|
|
assert( db->pPreUpdate->pNewUnpacked || db->pPreUpdate->aNew );
|
|
rc = sqlite3_preupdate_new(db, iCol, &pVal);
|
|
}else{
|
|
assert( db->pPreUpdate->pUnpacked );
|
|
rc = sqlite3_preupdate_old(db, iCol, &pVal);
|
|
}
|
|
assert( rc==SQLITE_OK );
|
|
if( sqlite3_value_type(pVal)!=eType ) return 0;
|
|
|
|
/* A SessionChange object never has a NULL value in a PK column */
|
|
assert( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT
|
|
|| eType==SQLITE_BLOB || eType==SQLITE_TEXT
|
|
);
|
|
|
|
if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){
|
|
i64 iVal = sessionGetI64(a);
|
|
a += 8;
|
|
if( eType==SQLITE_INTEGER ){
|
|
if( sqlite3_value_int64(pVal)!=iVal ) return 0;
|
|
}else{
|
|
double rVal;
|
|
assert( sizeof(iVal)==8 && sizeof(rVal)==8 );
|
|
memcpy(&rVal, &iVal, 8);
|
|
if( sqlite3_value_double(pVal)!=rVal ) return 0;
|
|
}
|
|
}else{
|
|
int n;
|
|
const u8 *z;
|
|
a += sessionVarintGet(a, &n);
|
|
if( sqlite3_value_bytes(pVal)!=n ) return 0;
|
|
if( eType==SQLITE_TEXT ){
|
|
z = sqlite3_value_text(pVal);
|
|
}else{
|
|
z = sqlite3_value_blob(pVal);
|
|
}
|
|
if( memcmp(a, z, n) ) return 0;
|
|
a += n;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
** If required, grow the hash table used to store changes on table pTab
|
|
** (part of the session pSession). If a fatal OOM error occurs, set the
|
|
** session object to failed and return SQLITE_ERROR. Otherwise, return
|
|
** SQLITE_OK.
|
|
**
|
|
** It is possible that a non-fatal OOM error occurs in this function. In
|
|
** that case the hash-table does not grow, but SQLITE_OK is returned anyway.
|
|
** Growing the hash table in this case is a performance optimization only,
|
|
** it is not required for correct operation.
|
|
*/
|
|
static int sessionGrowHash(int bPatchset, SessionTable *pTab){
|
|
if( pTab->nChange==0 || pTab->nEntry>=(pTab->nChange/2) ){
|
|
int i;
|
|
SessionChange **apNew;
|
|
int nNew = (pTab->nChange ? pTab->nChange : 128) * 2;
|
|
|
|
apNew = (SessionChange **)sqlite3_malloc(sizeof(SessionChange *) * nNew);
|
|
if( apNew==0 ){
|
|
if( pTab->nChange==0 ){
|
|
return SQLITE_ERROR;
|
|
}
|
|
return SQLITE_OK;
|
|
}
|
|
memset(apNew, 0, sizeof(SessionChange *) * nNew);
|
|
|
|
for(i=0; i<pTab->nChange; i++){
|
|
SessionChange *p;
|
|
SessionChange *pNext;
|
|
for(p=pTab->apChange[i]; p; p=pNext){
|
|
int bPkOnly = (p->op==SQLITE_DELETE && bPatchset);
|
|
int iHash = sessionChangeHash(pTab, bPkOnly, p->aRecord, nNew);
|
|
pNext = p->pNext;
|
|
p->pNext = apNew[iHash];
|
|
apNew[iHash] = p;
|
|
}
|
|
}
|
|
|
|
sqlite3_free(pTab->apChange);
|
|
pTab->nChange = nNew;
|
|
pTab->apChange = apNew;
|
|
}
|
|
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** This function queries the database for the names of the columns of table
|
|
** zThis, in schema zDb. It is expected that the table has nCol columns. If
|
|
** not, SQLITE_SCHEMA is returned and none of the output variables are
|
|
** populated.
|
|
**
|
|
** Otherwise, if they are not NULL, variable *pnCol is set to the number
|
|
** of columns in the database table and variable *pzTab is set to point to a
|
|
** nul-terminated copy of the table name. *pazCol (if not NULL) is set to
|
|
** point to an array of pointers to column names. And *pabPK (again, if not
|
|
** NULL) is set to point to an array of booleans - true if the corresponding
|
|
** column is part of the primary key.
|
|
**
|
|
** For example, if the table is declared as:
|
|
**
|
|
** CREATE TABLE tbl1(w, x, y, z, PRIMARY KEY(w, z));
|
|
**
|
|
** Then the four output variables are populated as follows:
|
|
**
|
|
** *pnCol = 4
|
|
** *pzTab = "tbl1"
|
|
** *pazCol = {"w", "x", "y", "z"}
|
|
** *pabPK = {1, 0, 0, 1}
|
|
**
|
|
** All returned buffers are part of the same single allocation, which must
|
|
** be freed using sqlite3_free() by the caller. If pazCol was not NULL, then
|
|
** pointer *pazCol should be freed to release all memory. Otherwise, pointer
|
|
** *pabPK. It is illegal for both pazCol and pabPK to be NULL.
|
|
*/
|
|
static int sessionTableInfo(
|
|
sqlite3 *db, /* Database connection */
|
|
const char *zDb, /* Name of attached database (e.g. "main") */
|
|
const char *zThis, /* Table name */
|
|
int *pnCol, /* OUT: number of columns */
|
|
const char **pzTab, /* OUT: Copy of zThis */
|
|
const char ***pazCol, /* OUT: Array of column names for table */
|
|
u8 **pabPK /* OUT: Array of booleans - true for PK col */
|
|
){
|
|
char *zPragma;
|
|
sqlite3_stmt *pStmt;
|
|
int rc;
|
|
int nByte;
|
|
int nDbCol = 0;
|
|
int nThis;
|
|
int i;
|
|
u8 *pAlloc;
|
|
char **azCol = 0;
|
|
u8 *abPK;
|
|
|
|
assert( pazCol && pabPK );
|
|
|
|
nThis = sqlite3Strlen30(zThis);
|
|
zPragma = sqlite3_mprintf("PRAGMA '%q'.table_info('%q')", zDb, zThis);
|
|
if( !zPragma ) return SQLITE_NOMEM;
|
|
|
|
rc = sqlite3_prepare_v2(db, zPragma, -1, &pStmt, 0);
|
|
sqlite3_free(zPragma);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
nByte = nThis + 1;
|
|
while( SQLITE_ROW==sqlite3_step(pStmt) ){
|
|
nByte += sqlite3_column_bytes(pStmt, 1);
|
|
nDbCol++;
|
|
}
|
|
rc = sqlite3_reset(pStmt);
|
|
|
|
if( rc==SQLITE_OK ){
|
|
nByte += nDbCol * (sizeof(const char *) + sizeof(u8) + 1);
|
|
pAlloc = sqlite3_malloc(nByte);
|
|
if( pAlloc==0 ){
|
|
rc = SQLITE_NOMEM;
|
|
}
|
|
}
|
|
if( rc==SQLITE_OK ){
|
|
azCol = (char **)pAlloc;
|
|
pAlloc = (u8 *)&azCol[nDbCol];
|
|
abPK = (u8 *)pAlloc;
|
|
pAlloc = &abPK[nDbCol];
|
|
if( pzTab ){
|
|
memcpy(pAlloc, zThis, nThis+1);
|
|
*pzTab = (char *)pAlloc;
|
|
pAlloc += nThis+1;
|
|
}
|
|
|
|
i = 0;
|
|
while( SQLITE_ROW==sqlite3_step(pStmt) ){
|
|
int nName = sqlite3_column_bytes(pStmt, 1);
|
|
const unsigned char *zName = sqlite3_column_text(pStmt, 1);
|
|
if( zName==0 ) break;
|
|
memcpy(pAlloc, zName, nName+1);
|
|
azCol[i] = (char *)pAlloc;
|
|
pAlloc += nName+1;
|
|
abPK[i] = sqlite3_column_int(pStmt, 5);
|
|
i++;
|
|
}
|
|
rc = sqlite3_reset(pStmt);
|
|
|
|
}
|
|
|
|
/* If successful, populate the output variables. Otherwise, zero them and
|
|
** free any allocation made. An error code will be returned in this case.
|
|
*/
|
|
if( rc==SQLITE_OK ){
|
|
*pazCol = (const char **)azCol;
|
|
*pabPK = abPK;
|
|
*pnCol = nDbCol;
|
|
}else{
|
|
*pazCol = 0;
|
|
*pabPK = 0;
|
|
*pnCol = 0;
|
|
if( pzTab ) *pzTab = 0;
|
|
sqlite3_free(azCol);
|
|
}
|
|
sqlite3_finalize(pStmt);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** This function is only called from within a pre-update handler for a
|
|
** write to table pTab, part of session pSession. If this is the first
|
|
** write to this table, set the SessionTable.nCol variable to the number
|
|
** of columns in the table.
|
|
**
|
|
** Otherwise, if this is not the first time this table has been written
|
|
** to, check that the number of columns in the table has not changed. If
|
|
** it has not, return zero.
|
|
**
|
|
** If the number of columns in the table has changed since the last write
|
|
** was recorded, set the session error-code to SQLITE_SCHEMA and return
|
|
** non-zero. Users are not allowed to change the number of columns in a table
|
|
** for which changes are being recorded by the session module. If they do so,
|
|
** it is an error.
|
|
*/
|
|
static int sessionInitTable(sqlite3_session *pSession, SessionTable *pTab){
|
|
if( pTab->nCol==0 ){
|
|
assert( pTab->azCol==0 || pTab->abPK==0 );
|
|
pSession->rc = sessionTableInfo(pSession->db, pSession->zDb,
|
|
pTab->zName, &pTab->nCol, 0, &pTab->azCol, &pTab->abPK
|
|
);
|
|
}
|
|
if( pSession->rc==SQLITE_OK
|
|
&& pTab->nCol!=sqlite3_preupdate_count(pSession->db)
|
|
){
|
|
pSession->rc = SQLITE_SCHEMA;
|
|
}
|
|
return pSession->rc;
|
|
}
|
|
|
|
/*
|
|
** This function is only called from with a pre-update-hook reporting a
|
|
** change on table pTab (attached to session pSession). The type of change
|
|
** (UPDATE, INSERT, DELETE) is specified by the first argument.
|
|
**
|
|
** Unless one is already present or an error occurs, an entry is added
|
|
** to the changed-rows hash table associated with table pTab.
|
|
*/
|
|
static void sessionPreupdateOneChange(
|
|
int op, /* One of SQLITE_UPDATE, INSERT, DELETE */
|
|
sqlite3_session *pSession, /* Session object pTab is attached to */
|
|
SessionTable *pTab /* Table that change applies to */
|
|
){
|
|
sqlite3 *db = pSession->db;
|
|
int iHash;
|
|
int bNullPk = 0;
|
|
int rc = SQLITE_OK;
|
|
|
|
if( pSession->rc ) return;
|
|
|
|
/* Load table details if required */
|
|
if( sessionInitTable(pSession, pTab) ) return;
|
|
|
|
/* Grow the hash table if required */
|
|
if( sessionGrowHash(0, pTab) ){
|
|
pSession->rc = SQLITE_NOMEM;
|
|
return;
|
|
}
|
|
|
|
/* Calculate the hash-key for this change. If the primary key of the row
|
|
** includes a NULL value, exit early. Such changes are ignored by the
|
|
** session module. */
|
|
rc = sessionPreupdateHash(db, pTab, op==SQLITE_INSERT, &iHash, &bNullPk);
|
|
if( rc!=SQLITE_OK ) goto error_out;
|
|
|
|
if( bNullPk==0 ){
|
|
/* Search the hash table for an existing record for this row. */
|
|
SessionChange *pC;
|
|
for(pC=pTab->apChange[iHash]; pC; pC=pC->pNext){
|
|
if( sessionPreupdateEqual(db, pTab, pC, op) ) break;
|
|
}
|
|
|
|
if( pC==0 ){
|
|
/* Create a new change object containing all the old values (if
|
|
** this is an SQLITE_UPDATE or SQLITE_DELETE), or just the PK
|
|
** values (if this is an INSERT). */
|
|
SessionChange *pChange; /* New change object */
|
|
int nByte; /* Number of bytes to allocate */
|
|
int i; /* Used to iterate through columns */
|
|
|
|
assert( rc==SQLITE_OK );
|
|
pTab->nEntry++;
|
|
|
|
/* Figure out how large an allocation is required */
|
|
nByte = sizeof(SessionChange);
|
|
for(i=0; i<pTab->nCol; i++){
|
|
sqlite3_value *p = 0;
|
|
if( op!=SQLITE_INSERT ){
|
|
TESTONLY(int trc = ) sqlite3_preupdate_old(pSession->db, i, &p);
|
|
assert( trc==SQLITE_OK );
|
|
}else if( pTab->abPK[i] ){
|
|
TESTONLY(int trc = ) sqlite3_preupdate_new(pSession->db, i, &p);
|
|
assert( trc==SQLITE_OK );
|
|
}
|
|
|
|
/* This may fail if SQLite value p contains a utf-16 string that must
|
|
** be converted to utf-8 and an OOM error occurs while doing so. */
|
|
rc = sessionSerializeValue(0, p, &nByte);
|
|
if( rc!=SQLITE_OK ) goto error_out;
|
|
}
|
|
|
|
/* Allocate the change object */
|
|
pChange = (SessionChange *)sqlite3_malloc(nByte);
|
|
if( !pChange ){
|
|
rc = SQLITE_NOMEM;
|
|
goto error_out;
|
|
}else{
|
|
memset(pChange, 0, sizeof(SessionChange));
|
|
pChange->aRecord = (u8 *)&pChange[1];
|
|
}
|
|
|
|
/* Populate the change object. None of the preupdate_old(),
|
|
** preupdate_new() or SerializeValue() calls below may fail as all
|
|
** required values and encodings have already been cached in memory.
|
|
** It is not possible for an OOM to occur in this block. */
|
|
nByte = 0;
|
|
for(i=0; i<pTab->nCol; i++){
|
|
sqlite3_value *p = 0;
|
|
if( op!=SQLITE_INSERT ){
|
|
sqlite3_preupdate_old(pSession->db, i, &p);
|
|
}else if( pTab->abPK[i] ){
|
|
sqlite3_preupdate_new(pSession->db, i, &p);
|
|
}
|
|
sessionSerializeValue(&pChange->aRecord[nByte], p, &nByte);
|
|
}
|
|
|
|
/* Add the change to the hash-table */
|
|
if( pSession->bIndirect || sqlite3_preupdate_depth(pSession->db) ){
|
|
pChange->bIndirect = 1;
|
|
}
|
|
pChange->nRecord = nByte;
|
|
pChange->op = op;
|
|
pChange->pNext = pTab->apChange[iHash];
|
|
pTab->apChange[iHash] = pChange;
|
|
|
|
}else if( pC->bIndirect ){
|
|
/* If the existing change is considered "indirect", but this current
|
|
** change is "direct", mark the change object as direct. */
|
|
if( sqlite3_preupdate_depth(pSession->db)==0 && pSession->bIndirect==0 ){
|
|
pC->bIndirect = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* If an error has occurred, mark the session object as failed. */
|
|
error_out:
|
|
if( rc!=SQLITE_OK ){
|
|
pSession->rc = rc;
|
|
}
|
|
}
|
|
|
|
/*
|
|
** The 'pre-update' hook registered by this module with SQLite databases.
|
|
*/
|
|
static void xPreUpdate(
|
|
void *pCtx, /* Copy of third arg to preupdate_hook() */
|
|
sqlite3 *db, /* Database handle */
|
|
int op, /* SQLITE_UPDATE, DELETE or INSERT */
|
|
char const *zDb, /* Database name */
|
|
char const *zName, /* Table name */
|
|
sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
|
|
sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
|
|
){
|
|
sqlite3_session *pSession;
|
|
int nDb = sqlite3Strlen30(zDb);
|
|
int nName = sqlite3Strlen30(zName);
|
|
|
|
assert( sqlite3_mutex_held(db->mutex) );
|
|
|
|
for(pSession=(sqlite3_session *)pCtx; pSession; pSession=pSession->pNext){
|
|
SessionTable *pTab;
|
|
|
|
/* If this session is attached to a different database ("main", "temp"
|
|
** etc.), or if it is not currently enabled, there is nothing to do. Skip
|
|
** to the next session object attached to this database. */
|
|
if( pSession->bEnable==0 ) continue;
|
|
if( pSession->rc ) continue;
|
|
if( sqlite3_strnicmp(zDb, pSession->zDb, nDb+1) ) continue;
|
|
|
|
for(pTab=pSession->pTable; pTab || pSession->bAutoAttach; pTab=pTab->pNext){
|
|
if( !pTab ){
|
|
/* This branch is taken if table zName has not yet been attached to
|
|
** this session and the auto-attach flag is set. */
|
|
|
|
/* If there is a table-filter configured, invoke it. If it returns 0,
|
|
** this change will not be recorded. Break out of the loop early in
|
|
** this case. */
|
|
if( pSession->xTableFilter
|
|
&& pSession->xTableFilter(pSession->pFilterCtx, zName)==0
|
|
){
|
|
break;
|
|
}
|
|
|
|
pSession->rc = sqlite3session_attach(pSession,zName);
|
|
if( pSession->rc ) break;
|
|
pTab = pSession->pTable;
|
|
assert( 0==sqlite3_strnicmp(pTab->zName, zName, nName+1) );
|
|
}
|
|
|
|
if( 0==sqlite3_strnicmp(pTab->zName, zName, nName+1) ){
|
|
sessionPreupdateOneChange(op, pSession, pTab);
|
|
if( op==SQLITE_UPDATE ){
|
|
sessionPreupdateOneChange(SQLITE_INSERT, pSession, pTab);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Create a session object. This session object will record changes to
|
|
** database zDb attached to connection db.
|
|
*/
|
|
int sqlite3session_create(
|
|
sqlite3 *db, /* Database handle */
|
|
const char *zDb, /* Name of db (e.g. "main") */
|
|
sqlite3_session **ppSession /* OUT: New session object */
|
|
){
|
|
sqlite3_session *pNew; /* Newly allocated session object */
|
|
sqlite3_session *pOld; /* Session object already attached to db */
|
|
int nDb = sqlite3Strlen30(zDb); /* Length of zDb in bytes */
|
|
|
|
/* Zero the output value in case an error occurs. */
|
|
*ppSession = 0;
|
|
|
|
/* Allocate and populate the new session object. */
|
|
pNew = (sqlite3_session *)sqlite3_malloc(sizeof(sqlite3_session) + nDb + 1);
|
|
if( !pNew ) return SQLITE_NOMEM;
|
|
memset(pNew, 0, sizeof(sqlite3_session));
|
|
pNew->db = db;
|
|
pNew->zDb = (char *)&pNew[1];
|
|
pNew->bEnable = 1;
|
|
memcpy(pNew->zDb, zDb, nDb+1);
|
|
|
|
/* Add the new session object to the linked list of session objects
|
|
** attached to database handle $db. Do this under the cover of the db
|
|
** handle mutex. */
|
|
sqlite3_mutex_enter(sqlite3_db_mutex(db));
|
|
pOld = (sqlite3_session*)sqlite3_preupdate_hook(db, xPreUpdate, (void*)pNew);
|
|
pNew->pNext = pOld;
|
|
sqlite3_mutex_leave(sqlite3_db_mutex(db));
|
|
|
|
*ppSession = pNew;
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Free the list of table objects passed as the first argument. The contents
|
|
** of the changed-rows hash tables are also deleted.
|
|
*/
|
|
static void sessionDeleteTable(SessionTable *pList){
|
|
SessionTable *pNext;
|
|
SessionTable *pTab;
|
|
|
|
for(pTab=pList; pTab; pTab=pNext){
|
|
int i;
|
|
pNext = pTab->pNext;
|
|
for(i=0; i<pTab->nChange; i++){
|
|
SessionChange *p;
|
|
SessionChange *pNext;
|
|
for(p=pTab->apChange[i]; p; p=pNext){
|
|
pNext = p->pNext;
|
|
sqlite3_free(p);
|
|
}
|
|
}
|
|
sqlite3_free((char*)pTab->azCol); /* cast works around VC++ bug */
|
|
sqlite3_free(pTab->apChange);
|
|
sqlite3_free(pTab);
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Delete a session object previously allocated using sqlite3session_create().
|
|
*/
|
|
void sqlite3session_delete(sqlite3_session *pSession){
|
|
sqlite3 *db = pSession->db;
|
|
sqlite3_session *pHead;
|
|
sqlite3_session **pp;
|
|
|
|
/* Unlink the session from the linked list of sessions attached to the
|
|
** database handle. Hold the db mutex while doing so. */
|
|
sqlite3_mutex_enter(sqlite3_db_mutex(db));
|
|
pHead = (sqlite3_session*)sqlite3_preupdate_hook(db, 0, 0);
|
|
for(pp=&pHead; (*pp)!=pSession; pp=&((*pp)->pNext));
|
|
*pp = (*pp)->pNext;
|
|
if( pHead ) sqlite3_preupdate_hook(db, xPreUpdate, (void *)pHead);
|
|
sqlite3_mutex_leave(sqlite3_db_mutex(db));
|
|
|
|
/* Delete all attached table objects. And the contents of their
|
|
** associated hash-tables. */
|
|
sessionDeleteTable(pSession->pTable);
|
|
|
|
/* Free the session object itself. */
|
|
sqlite3_free(pSession);
|
|
}
|
|
|
|
/*
|
|
** Set a table filter on a Session Object.
|
|
*/
|
|
void sqlite3session_table_filter(
|
|
sqlite3_session *pSession,
|
|
int(*xFilter)(void*, const char*),
|
|
void *pCtx /* First argument passed to xFilter */
|
|
){
|
|
pSession->bAutoAttach = 1;
|
|
pSession->pFilterCtx = pCtx;
|
|
pSession->xTableFilter = xFilter;
|
|
}
|
|
|
|
/*
|
|
** Attach a table to a session. All subsequent changes made to the table
|
|
** while the session object is enabled will be recorded.
|
|
**
|
|
** Only tables that have a PRIMARY KEY defined may be attached. It does
|
|
** not matter if the PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias)
|
|
** or not.
|
|
*/
|
|
int sqlite3session_attach(
|
|
sqlite3_session *pSession, /* Session object */
|
|
const char *zName /* Table name */
|
|
){
|
|
int rc = SQLITE_OK;
|
|
sqlite3_mutex_enter(sqlite3_db_mutex(pSession->db));
|
|
|
|
if( !zName ){
|
|
pSession->bAutoAttach = 1;
|
|
}else{
|
|
SessionTable *pTab; /* New table object (if required) */
|
|
int nName; /* Number of bytes in string zName */
|
|
|
|
/* First search for an existing entry. If one is found, this call is
|
|
** a no-op. Return early. */
|
|
nName = sqlite3Strlen30(zName);
|
|
for(pTab=pSession->pTable; pTab; pTab=pTab->pNext){
|
|
if( 0==sqlite3_strnicmp(pTab->zName, zName, nName+1) ) break;
|
|
}
|
|
|
|
if( !pTab ){
|
|
/* Allocate new SessionTable object. */
|
|
pTab = (SessionTable *)sqlite3_malloc(sizeof(SessionTable) + nName + 1);
|
|
if( !pTab ){
|
|
rc = SQLITE_NOMEM;
|
|
}else{
|
|
/* Populate the new SessionTable object and link it into the list. */
|
|
memset(pTab, 0, sizeof(SessionTable));
|
|
pTab->zName = (char *)&pTab[1];
|
|
memcpy(pTab->zName, zName, nName+1);
|
|
pTab->pNext = pSession->pTable;
|
|
pSession->pTable = pTab;
|
|
}
|
|
}
|
|
}
|
|
|
|
sqlite3_mutex_leave(sqlite3_db_mutex(pSession->db));
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Ensure that there is room in the buffer to append nByte bytes of data.
|
|
** If not, use sqlite3_realloc() to grow the buffer so that there is.
|
|
**
|
|
** If successful, return zero. Otherwise, if an OOM condition is encountered,
|
|
** set *pRc to SQLITE_NOMEM and return non-zero.
|
|
*/
|
|
static int sessionBufferGrow(SessionBuffer *p, int nByte, int *pRc){
|
|
if( *pRc==SQLITE_OK && p->nAlloc-p->nBuf<nByte ){
|
|
u8 *aNew;
|
|
int nNew = p->nAlloc ? p->nAlloc : 128;
|
|
do {
|
|
nNew = nNew*2;
|
|
}while( nNew<(p->nAlloc+nByte) );
|
|
|
|
aNew = (u8 *)sqlite3_realloc(p->aBuf, nNew);
|
|
if( 0==aNew ){
|
|
*pRc = SQLITE_NOMEM;
|
|
}else{
|
|
p->aBuf = aNew;
|
|
p->nAlloc = nNew;
|
|
}
|
|
}
|
|
return (*pRc!=SQLITE_OK);
|
|
}
|
|
|
|
/*
|
|
** This function is a no-op if *pRc is other than SQLITE_OK when it is
|
|
** called. Otherwise, append a single byte to the buffer.
|
|
**
|
|
** If an OOM condition is encountered, set *pRc to SQLITE_NOMEM before
|
|
** returning.
|
|
*/
|
|
static void sessionAppendByte(SessionBuffer *p, u8 v, int *pRc){
|
|
if( 0==sessionBufferGrow(p, 1, pRc) ){
|
|
p->aBuf[p->nBuf++] = v;
|
|
}
|
|
}
|
|
|
|
/*
|
|
** This function is a no-op if *pRc is other than SQLITE_OK when it is
|
|
** called. Otherwise, append a single varint to the buffer.
|
|
**
|
|
** If an OOM condition is encountered, set *pRc to SQLITE_NOMEM before
|
|
** returning.
|
|
*/
|
|
static void sessionAppendVarint(SessionBuffer *p, int v, int *pRc){
|
|
if( 0==sessionBufferGrow(p, 9, pRc) ){
|
|
p->nBuf += sessionVarintPut(&p->aBuf[p->nBuf], v);
|
|
}
|
|
}
|
|
|
|
/*
|
|
** This function is a no-op if *pRc is other than SQLITE_OK when it is
|
|
** called. Otherwise, append a blob of data to the buffer.
|
|
**
|
|
** If an OOM condition is encountered, set *pRc to SQLITE_NOMEM before
|
|
** returning.
|
|
*/
|
|
static void sessionAppendBlob(
|
|
SessionBuffer *p,
|
|
const u8 *aBlob,
|
|
int nBlob,
|
|
int *pRc
|
|
){
|
|
if( 0==sessionBufferGrow(p, nBlob, pRc) ){
|
|
memcpy(&p->aBuf[p->nBuf], aBlob, nBlob);
|
|
p->nBuf += nBlob;
|
|
}
|
|
}
|
|
|
|
/*
|
|
** This function is a no-op if *pRc is other than SQLITE_OK when it is
|
|
** called. Otherwise, append a string to the buffer. All bytes in the string
|
|
** up to (but not including) the nul-terminator are written to the buffer.
|
|
**
|
|
** If an OOM condition is encountered, set *pRc to SQLITE_NOMEM before
|
|
** returning.
|
|
*/
|
|
static void sessionAppendStr(
|
|
SessionBuffer *p,
|
|
const char *zStr,
|
|
int *pRc
|
|
){
|
|
int nStr = sqlite3Strlen30(zStr);
|
|
if( 0==sessionBufferGrow(p, nStr, pRc) ){
|
|
memcpy(&p->aBuf[p->nBuf], zStr, nStr);
|
|
p->nBuf += nStr;
|
|
}
|
|
}
|
|
|
|
/*
|
|
** This function is a no-op if *pRc is other than SQLITE_OK when it is
|
|
** called. Otherwise, append the string representation of integer iVal
|
|
** to the buffer. No nul-terminator is written.
|
|
**
|
|
** If an OOM condition is encountered, set *pRc to SQLITE_NOMEM before
|
|
** returning.
|
|
*/
|
|
static void sessionAppendInteger(
|
|
SessionBuffer *p, /* Buffer to append to */
|
|
int iVal, /* Value to write the string rep. of */
|
|
int *pRc /* IN/OUT: Error code */
|
|
){
|
|
char aBuf[24];
|
|
sqlite3_snprintf(sizeof(aBuf)-1, aBuf, "%d", iVal);
|
|
sessionAppendStr(p, aBuf, pRc);
|
|
}
|
|
|
|
/*
|
|
** This function is a no-op if *pRc is other than SQLITE_OK when it is
|
|
** called. Otherwise, append the string zStr enclosed in quotes (") and
|
|
** with any embedded quote characters escaped to the buffer. No
|
|
** nul-terminator byte is written.
|
|
**
|
|
** If an OOM condition is encountered, set *pRc to SQLITE_NOMEM before
|
|
** returning.
|
|
*/
|
|
static void sessionAppendIdent(
|
|
SessionBuffer *p, /* Buffer to a append to */
|
|
const char *zStr, /* String to quote, escape and append */
|
|
int *pRc /* IN/OUT: Error code */
|
|
){
|
|
int nStr = sqlite3Strlen30(zStr)*2 + 2 + 1;
|
|
if( 0==sessionBufferGrow(p, nStr, pRc) ){
|
|
char *zOut = (char *)&p->aBuf[p->nBuf];
|
|
const char *zIn = zStr;
|
|
*zOut++ = '"';
|
|
while( *zIn ){
|
|
if( *zIn=='"' ) *zOut++ = '"';
|
|
*zOut++ = *(zIn++);
|
|
}
|
|
*zOut++ = '"';
|
|
p->nBuf = (int)((u8 *)zOut - p->aBuf);
|
|
}
|
|
}
|
|
|
|
/*
|
|
** This function is a no-op if *pRc is other than SQLITE_OK when it is
|
|
** called. Otherwse, it appends the serialized version of the value stored
|
|
** in column iCol of the row that SQL statement pStmt currently points
|
|
** to to the buffer.
|
|
*/
|
|
static void sessionAppendCol(
|
|
SessionBuffer *p, /* Buffer to append to */
|
|
sqlite3_stmt *pStmt, /* Handle pointing to row containing value */
|
|
int iCol, /* Column to read value from */
|
|
int *pRc /* IN/OUT: Error code */
|
|
){
|
|
if( *pRc==SQLITE_OK ){
|
|
int eType = sqlite3_column_type(pStmt, iCol);
|
|
sessionAppendByte(p, (u8)eType, pRc);
|
|
if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){
|
|
sqlite3_int64 i;
|
|
u8 aBuf[8];
|
|
if( eType==SQLITE_INTEGER ){
|
|
i = sqlite3_column_int64(pStmt, iCol);
|
|
}else{
|
|
double r = sqlite3_column_double(pStmt, iCol);
|
|
memcpy(&i, &r, 8);
|
|
}
|
|
sessionPutI64(aBuf, i);
|
|
sessionAppendBlob(p, aBuf, 8, pRc);
|
|
}
|
|
if( eType==SQLITE_BLOB || eType==SQLITE_TEXT ){
|
|
u8 *z;
|
|
if( eType==SQLITE_BLOB ){
|
|
z = (u8 *)sqlite3_column_blob(pStmt, iCol);
|
|
}else{
|
|
z = (u8 *)sqlite3_column_text(pStmt, iCol);
|
|
}
|
|
if( z ){
|
|
int nByte = sqlite3_column_bytes(pStmt, iCol);
|
|
sessionAppendVarint(p, nByte, pRc);
|
|
sessionAppendBlob(p, z, nByte, pRc);
|
|
}else{
|
|
*pRc = SQLITE_NOMEM;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
**
|
|
** This function appends an update change to the buffer (see the comments
|
|
** under "CHANGESET FORMAT" at the top of the file). An update change
|
|
** consists of:
|
|
**
|
|
** 1 byte: SQLITE_UPDATE (0x17)
|
|
** n bytes: old.* record (see RECORD FORMAT)
|
|
** m bytes: new.* record (see RECORD FORMAT)
|
|
**
|
|
** The SessionChange object passed as the third argument contains the
|
|
** values that were stored in the row when the session began (the old.*
|
|
** values). The statement handle passed as the second argument points
|
|
** at the current version of the row (the new.* values).
|
|
**
|
|
** If all of the old.* values are equal to their corresponding new.* value
|
|
** (i.e. nothing has changed), then no data at all is appended to the buffer.
|
|
**
|
|
** Otherwise, the old.* record contains all primary key values and the
|
|
** original values of any fields that have been modified. The new.* record
|
|
** contains the new values of only those fields that have been modified.
|
|
*/
|
|
static int sessionAppendUpdate(
|
|
SessionBuffer *pBuf, /* Buffer to append to */
|
|
int bPatchset, /* True for "patchset", 0 for "changeset" */
|
|
sqlite3_stmt *pStmt, /* Statement handle pointing at new row */
|
|
SessionChange *p, /* Object containing old values */
|
|
u8 *abPK /* Boolean array - true for PK columns */
|
|
){
|
|
int rc = SQLITE_OK;
|
|
SessionBuffer buf2 = {0,0,0}; /* Buffer to accumulate new.* record in */
|
|
int bNoop = 1; /* Set to zero if any values are modified */
|
|
int nRewind = pBuf->nBuf; /* Set to zero if any values are modified */
|
|
int i; /* Used to iterate through columns */
|
|
u8 *pCsr = p->aRecord; /* Used to iterate through old.* values */
|
|
|
|
sessionAppendByte(pBuf, SQLITE_UPDATE, &rc);
|
|
sessionAppendByte(pBuf, p->bIndirect, &rc);
|
|
for(i=0; i<sqlite3_column_count(pStmt); i++){
|
|
int bChanged = 0;
|
|
int nAdvance;
|
|
int eType = *pCsr;
|
|
switch( eType ){
|
|
case SQLITE_NULL:
|
|
nAdvance = 1;
|
|
if( sqlite3_column_type(pStmt, i)!=SQLITE_NULL ){
|
|
bChanged = 1;
|
|
}
|
|
break;
|
|
|
|
case SQLITE_FLOAT:
|
|
case SQLITE_INTEGER: {
|
|
nAdvance = 9;
|
|
if( eType==sqlite3_column_type(pStmt, i) ){
|
|
sqlite3_int64 iVal = sessionGetI64(&pCsr[1]);
|
|
if( eType==SQLITE_INTEGER ){
|
|
if( iVal==sqlite3_column_int64(pStmt, i) ) break;
|
|
}else{
|
|
double dVal;
|
|
memcpy(&dVal, &iVal, 8);
|
|
if( dVal==sqlite3_column_double(pStmt, i) ) break;
|
|
}
|
|
}
|
|
bChanged = 1;
|
|
break;
|
|
}
|
|
|
|
default: {
|
|
int nByte;
|
|
int nHdr = 1 + sessionVarintGet(&pCsr[1], &nByte);
|
|
assert( eType==SQLITE_TEXT || eType==SQLITE_BLOB );
|
|
nAdvance = nHdr + nByte;
|
|
if( eType==sqlite3_column_type(pStmt, i)
|
|
&& nByte==sqlite3_column_bytes(pStmt, i)
|
|
&& 0==memcmp(&pCsr[nHdr], sqlite3_column_blob(pStmt, i), nByte)
|
|
){
|
|
break;
|
|
}
|
|
bChanged = 1;
|
|
}
|
|
}
|
|
|
|
/* If at least one field has been modified, this is not a no-op. */
|
|
if( bChanged ) bNoop = 0;
|
|
|
|
/* Add a field to the old.* record. This is omitted if this modules is
|
|
** currently generating a patchset. */
|
|
if( bPatchset==0 ){
|
|
if( bChanged || abPK[i] ){
|
|
sessionAppendBlob(pBuf, pCsr, nAdvance, &rc);
|
|
}else{
|
|
sessionAppendByte(pBuf, 0, &rc);
|
|
}
|
|
}
|
|
|
|
/* Add a field to the new.* record. Or the only record if currently
|
|
** generating a patchset. */
|
|
if( bChanged || (bPatchset && abPK[i]) ){
|
|
sessionAppendCol(&buf2, pStmt, i, &rc);
|
|
}else{
|
|
sessionAppendByte(&buf2, 0, &rc);
|
|
}
|
|
|
|
pCsr += nAdvance;
|
|
}
|
|
|
|
if( bNoop ){
|
|
pBuf->nBuf = nRewind;
|
|
}else{
|
|
sessionAppendBlob(pBuf, buf2.aBuf, buf2.nBuf, &rc);
|
|
}
|
|
sqlite3_free(buf2.aBuf);
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Append a DELETE change to the buffer passed as the first argument. Use
|
|
** the changeset format if argument bPatchset is zero, or the patchset
|
|
** format otherwise.
|
|
*/
|
|
static int sessionAppendDelete(
|
|
SessionBuffer *pBuf, /* Buffer to append to */
|
|
int bPatchset, /* True for "patchset", 0 for "changeset" */
|
|
SessionChange *p, /* Object containing old values */
|
|
int nCol, /* Number of columns in table */
|
|
u8 *abPK /* Boolean array - true for PK columns */
|
|
){
|
|
int rc = SQLITE_OK;
|
|
|
|
sessionAppendByte(pBuf, SQLITE_DELETE, &rc);
|
|
sessionAppendByte(pBuf, p->bIndirect, &rc);
|
|
|
|
if( bPatchset==0 ){
|
|
sessionAppendBlob(pBuf, p->aRecord, p->nRecord, &rc);
|
|
}else{
|
|
int i;
|
|
u8 *a = p->aRecord;
|
|
for(i=0; i<nCol; i++){
|
|
u8 *pStart = a;
|
|
int eType = *a++;
|
|
|
|
switch( eType ){
|
|
case 0:
|
|
case SQLITE_NULL:
|
|
assert( abPK[i]==0 );
|
|
break;
|
|
|
|
case SQLITE_FLOAT:
|
|
case SQLITE_INTEGER:
|
|
a += 8;
|
|
break;
|
|
|
|
default: {
|
|
int n;
|
|
a += sessionVarintGet(a, &n);
|
|
a += n;
|
|
break;
|
|
}
|
|
}
|
|
if( abPK[i] ){
|
|
sessionAppendBlob(pBuf, pStart, a-pStart, &rc);
|
|
}
|
|
}
|
|
assert( (a - p->aRecord)==p->nRecord );
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Formulate and prepare a SELECT statement to retrieve a row from table
|
|
** zTab in database zDb based on its primary key. i.e.
|
|
**
|
|
** SELECT * FROM zDb.zTab WHERE pk1 = ? AND pk2 = ? AND ...
|
|
*/
|
|
static int sessionSelectStmt(
|
|
sqlite3 *db, /* Database handle */
|
|
const char *zDb, /* Database name */
|
|
const char *zTab, /* Table name */
|
|
int nCol, /* Number of columns in table */
|
|
const char **azCol, /* Names of table columns */
|
|
u8 *abPK, /* PRIMARY KEY array */
|
|
sqlite3_stmt **ppStmt /* OUT: Prepared SELECT statement */
|
|
){
|
|
int rc = SQLITE_OK;
|
|
int i;
|
|
const char *zSep = "";
|
|
SessionBuffer buf = {0, 0, 0};
|
|
|
|
sessionAppendStr(&buf, "SELECT * FROM ", &rc);
|
|
sessionAppendIdent(&buf, zDb, &rc);
|
|
sessionAppendStr(&buf, ".", &rc);
|
|
sessionAppendIdent(&buf, zTab, &rc);
|
|
sessionAppendStr(&buf, " WHERE ", &rc);
|
|
for(i=0; i<nCol; i++){
|
|
if( abPK[i] ){
|
|
sessionAppendStr(&buf, zSep, &rc);
|
|
sessionAppendIdent(&buf, azCol[i], &rc);
|
|
sessionAppendStr(&buf, " = ?", &rc);
|
|
sessionAppendInteger(&buf, i+1, &rc);
|
|
zSep = " AND ";
|
|
}
|
|
}
|
|
if( rc==SQLITE_OK ){
|
|
rc = sqlite3_prepare_v2(db, (char *)buf.aBuf, buf.nBuf, ppStmt, 0);
|
|
}
|
|
sqlite3_free(buf.aBuf);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Bind the PRIMARY KEY values from the change passed in argument pChange
|
|
** to the SELECT statement passed as the first argument. The SELECT statement
|
|
** is as prepared by function sessionSelectStmt().
|
|
**
|
|
** Return SQLITE_OK if all PK values are successfully bound, or an SQLite
|
|
** error code (e.g. SQLITE_NOMEM) otherwise.
|
|
*/
|
|
static int sessionSelectBind(
|
|
sqlite3_stmt *pSelect, /* SELECT from sessionSelectStmt() */
|
|
int nCol, /* Number of columns in table */
|
|
u8 *abPK, /* PRIMARY KEY array */
|
|
SessionChange *pChange /* Change structure */
|
|
){
|
|
int i;
|
|
int rc = SQLITE_OK;
|
|
u8 *a = pChange->aRecord;
|
|
|
|
for(i=0; i<nCol && rc==SQLITE_OK; i++){
|
|
int eType = *a++;
|
|
|
|
switch( eType ){
|
|
case 0:
|
|
case SQLITE_NULL:
|
|
assert( abPK[i]==0 );
|
|
break;
|
|
|
|
case SQLITE_INTEGER: {
|
|
if( abPK[i] ){
|
|
i64 iVal = sessionGetI64(a);
|
|
rc = sqlite3_bind_int64(pSelect, i+1, iVal);
|
|
}
|
|
a += 8;
|
|
break;
|
|
}
|
|
|
|
case SQLITE_FLOAT: {
|
|
if( abPK[i] ){
|
|
double rVal;
|
|
i64 iVal = sessionGetI64(a);
|
|
memcpy(&rVal, &iVal, 8);
|
|
rc = sqlite3_bind_double(pSelect, i+1, rVal);
|
|
}
|
|
a += 8;
|
|
break;
|
|
}
|
|
|
|
case SQLITE_TEXT: {
|
|
int n;
|
|
a += sessionVarintGet(a, &n);
|
|
if( abPK[i] ){
|
|
rc = sqlite3_bind_text(pSelect, i+1, (char *)a, n, SQLITE_TRANSIENT);
|
|
}
|
|
a += n;
|
|
break;
|
|
}
|
|
|
|
default: {
|
|
int n;
|
|
assert( eType==SQLITE_BLOB );
|
|
a += sessionVarintGet(a, &n);
|
|
if( abPK[i] ){
|
|
rc = sqlite3_bind_blob(pSelect, i+1, a, n, SQLITE_TRANSIENT);
|
|
}
|
|
a += n;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** This function is a no-op if *pRc is set to other than SQLITE_OK when it
|
|
** is called. Otherwise, append a serialized table header (part of the binary
|
|
** changeset format) to buffer *pBuf. If an error occurs, set *pRc to an
|
|
** SQLite error code before returning.
|
|
*/
|
|
static void sessionAppendTableHdr(
|
|
SessionBuffer *pBuf, /* Append header to this buffer */
|
|
int bPatchset, /* Use the patchset format if true */
|
|
SessionTable *pTab, /* Table object to append header for */
|
|
int *pRc /* IN/OUT: Error code */
|
|
){
|
|
/* Write a table header */
|
|
sessionAppendByte(pBuf, (bPatchset ? 'P' : 'T'), pRc);
|
|
sessionAppendVarint(pBuf, pTab->nCol, pRc);
|
|
sessionAppendBlob(pBuf, pTab->abPK, pTab->nCol, pRc);
|
|
sessionAppendBlob(pBuf, (u8 *)pTab->zName, (int)strlen(pTab->zName)+1, pRc);
|
|
}
|
|
|
|
/*
|
|
** Generate either a changeset (if argument bPatchset is zero) or a patchset
|
|
** (if it is non-zero) based on the current contents of the session object
|
|
** passed as the first argument.
|
|
**
|
|
** If no error occurs, SQLITE_OK is returned and the new changeset/patchset
|
|
** stored in output variables *pnChangeset and *ppChangeset. Or, if an error
|
|
** occurs, an SQLite error code is returned and both output variables set
|
|
** to 0.
|
|
*/
|
|
int sessionGenerateChangeset(
|
|
sqlite3_session *pSession, /* Session object */
|
|
int bPatchset, /* True for patchset, false for changeset */
|
|
int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
|
|
void **ppChangeset /* OUT: Buffer containing changeset */
|
|
){
|
|
sqlite3 *db = pSession->db; /* Source database handle */
|
|
SessionTable *pTab; /* Used to iterate through attached tables */
|
|
SessionBuffer buf = {0,0,0}; /* Buffer in which to accumlate changeset */
|
|
int rc; /* Return code */
|
|
|
|
/* Zero the output variables in case an error occurs. If this session
|
|
** object is already in the error state (sqlite3_session.rc != SQLITE_OK),
|
|
** this call will be a no-op. */
|
|
*pnChangeset = 0;
|
|
*ppChangeset = 0;
|
|
|
|
if( pSession->rc ) return pSession->rc;
|
|
rc = sqlite3_exec(pSession->db, "SAVEPOINT changeset", 0, 0, 0);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
sqlite3_mutex_enter(sqlite3_db_mutex(db));
|
|
|
|
for(pTab=pSession->pTable; rc==SQLITE_OK && pTab; pTab=pTab->pNext){
|
|
if( pTab->nEntry ){
|
|
const char *zName = pTab->zName;
|
|
int nCol; /* Number of columns in table */
|
|
u8 *abPK; /* Primary key array */
|
|
const char **azCol = 0; /* Table columns */
|
|
int i; /* Used to iterate through hash buckets */
|
|
sqlite3_stmt *pSel = 0; /* SELECT statement to query table pTab */
|
|
int nRewind = buf.nBuf; /* Initial size of write buffer */
|
|
int nNoop; /* Size of buffer after writing tbl header */
|
|
|
|
/* Check the table schema is still Ok. */
|
|
rc = sessionTableInfo(db, pSession->zDb, zName, &nCol, 0, &azCol, &abPK);
|
|
if( !rc && (pTab->nCol!=nCol || memcmp(abPK, pTab->abPK, nCol)) ){
|
|
rc = SQLITE_SCHEMA;
|
|
}
|
|
|
|
/* Write a table header */
|
|
sessionAppendTableHdr(&buf, bPatchset, pTab, &rc);
|
|
|
|
/* Build and compile a statement to execute: */
|
|
if( rc==SQLITE_OK ){
|
|
rc = sessionSelectStmt(
|
|
db, pSession->zDb, zName, nCol, azCol, abPK, &pSel);
|
|
}
|
|
|
|
nNoop = buf.nBuf;
|
|
for(i=0; i<pTab->nChange && rc==SQLITE_OK; i++){
|
|
SessionChange *p; /* Used to iterate through changes */
|
|
|
|
for(p=pTab->apChange[i]; rc==SQLITE_OK && p; p=p->pNext){
|
|
rc = sessionSelectBind(pSel, nCol, abPK, p);
|
|
if( rc!=SQLITE_OK ) continue;
|
|
if( sqlite3_step(pSel)==SQLITE_ROW ){
|
|
if( p->op==SQLITE_INSERT ){
|
|
int iCol;
|
|
sessionAppendByte(&buf, SQLITE_INSERT, &rc);
|
|
sessionAppendByte(&buf, p->bIndirect, &rc);
|
|
for(iCol=0; iCol<nCol; iCol++){
|
|
sessionAppendCol(&buf, pSel, iCol, &rc);
|
|
}
|
|
}else{
|
|
rc = sessionAppendUpdate(&buf, bPatchset, pSel, p, abPK);
|
|
}
|
|
}else if( p->op!=SQLITE_INSERT ){
|
|
rc = sessionAppendDelete(&buf, bPatchset, p, nCol, abPK);
|
|
}
|
|
if( rc==SQLITE_OK ){
|
|
rc = sqlite3_reset(pSel);
|
|
}
|
|
}
|
|
}
|
|
|
|
sqlite3_finalize(pSel);
|
|
if( buf.nBuf==nNoop ){
|
|
buf.nBuf = nRewind;
|
|
}
|
|
sqlite3_free((char*)azCol); /* cast works around VC++ bug */
|
|
}
|
|
}
|
|
|
|
if( rc==SQLITE_OK ){
|
|
*pnChangeset = buf.nBuf;
|
|
*ppChangeset = buf.aBuf;
|
|
}else{
|
|
sqlite3_free(buf.aBuf);
|
|
}
|
|
|
|
sqlite3_exec(db, "RELEASE changeset", 0, 0, 0);
|
|
sqlite3_mutex_leave(sqlite3_db_mutex(db));
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Obtain a changeset object containing all changes recorded by the
|
|
** session object passed as the first argument.
|
|
**
|
|
** It is the responsibility of the caller to eventually free the buffer
|
|
** using sqlite3_free().
|
|
*/
|
|
int sqlite3session_changeset(
|
|
sqlite3_session *pSession, /* Session object */
|
|
int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
|
|
void **ppChangeset /* OUT: Buffer containing changeset */
|
|
){
|
|
return sessionGenerateChangeset(pSession, 0, pnChangeset, ppChangeset);
|
|
}
|
|
|
|
/*
|
|
** Obtain a patchset object containing all changes recorded by the
|
|
** session object passed as the first argument.
|
|
**
|
|
** It is the responsibility of the caller to eventually free the buffer
|
|
** using sqlite3_free().
|
|
*/
|
|
int sqlite3session_patchset(
|
|
sqlite3_session *pSession, /* Session object */
|
|
int *pnPatchset, /* OUT: Size of buffer at *ppChangeset */
|
|
void **ppPatchset /* OUT: Buffer containing changeset */
|
|
){
|
|
return sessionGenerateChangeset(pSession, 1, pnPatchset, ppPatchset);
|
|
}
|
|
|
|
/*
|
|
** Enable or disable the session object passed as the first argument.
|
|
*/
|
|
int sqlite3session_enable(sqlite3_session *pSession, int bEnable){
|
|
int ret;
|
|
sqlite3_mutex_enter(sqlite3_db_mutex(pSession->db));
|
|
if( bEnable>=0 ){
|
|
pSession->bEnable = bEnable;
|
|
}
|
|
ret = pSession->bEnable;
|
|
sqlite3_mutex_leave(sqlite3_db_mutex(pSession->db));
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
** Enable or disable the session object passed as the first argument.
|
|
*/
|
|
int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect){
|
|
int ret;
|
|
sqlite3_mutex_enter(sqlite3_db_mutex(pSession->db));
|
|
if( bIndirect>=0 ){
|
|
pSession->bIndirect = bIndirect;
|
|
}
|
|
ret = pSession->bIndirect;
|
|
sqlite3_mutex_leave(sqlite3_db_mutex(pSession->db));
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
** Return true if there have been no changes to monitored tables recorded
|
|
** by the session object passed as the only argument.
|
|
*/
|
|
int sqlite3session_isempty(sqlite3_session *pSession){
|
|
int ret = 0;
|
|
SessionTable *pTab;
|
|
|
|
sqlite3_mutex_enter(sqlite3_db_mutex(pSession->db));
|
|
for(pTab=pSession->pTable; pTab && ret==0; pTab=pTab->pNext){
|
|
ret = (pTab->nEntry>0);
|
|
}
|
|
sqlite3_mutex_leave(sqlite3_db_mutex(pSession->db));
|
|
|
|
return (ret==0);
|
|
}
|
|
|
|
/*
|
|
** Create an iterator used to iterate through the contents of a changeset.
|
|
*/
|
|
int sqlite3changeset_start(
|
|
sqlite3_changeset_iter **pp, /* OUT: Changeset iterator handle */
|
|
int nChangeset, /* Size of buffer pChangeset in bytes */
|
|
void *pChangeset /* Pointer to buffer containing changeset */
|
|
){
|
|
sqlite3_changeset_iter *pRet; /* Iterator to return */
|
|
int nByte; /* Number of bytes to allocate for iterator */
|
|
|
|
/* Zero the output variable in case an error occurs. */
|
|
*pp = 0;
|
|
|
|
/* Allocate and initialize the iterator structure. */
|
|
nByte = sizeof(sqlite3_changeset_iter);
|
|
pRet = (sqlite3_changeset_iter *)sqlite3_malloc(nByte);
|
|
if( !pRet ) return SQLITE_NOMEM;
|
|
memset(pRet, 0, sizeof(sqlite3_changeset_iter));
|
|
pRet->aChangeset = (u8 *)pChangeset;
|
|
pRet->nChangeset = nChangeset;
|
|
pRet->pNext = pRet->aChangeset;
|
|
|
|
/* Populate the output variable and return success. */
|
|
*pp = pRet;
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Deserialize a single record from a buffer in memory. See "RECORD FORMAT"
|
|
** for details.
|
|
**
|
|
** When this function is called, *paChange points to the start of the record
|
|
** to deserialize. Assuming no error occurs, *paChange is set to point to
|
|
** one byte after the end of the same record before this function returns.
|
|
** If the argument abPK is NULL, then the record contains nCol values. Or,
|
|
** if abPK is other than NULL, then the record contains only the PK fields
|
|
** (in other words, it is a patchset DELETE record).
|
|
**
|
|
** If successful, each element of the apOut[] array (allocated by the caller)
|
|
** is set to point to an sqlite3_value object containing the value read
|
|
** from the corresponding position in the record. If that value is not
|
|
** included in the record (i.e. because the record is part of an UPDATE change
|
|
** and the field was not modified), the corresponding element of apOut[] is
|
|
** set to NULL.
|
|
**
|
|
** It is the responsibility of the caller to free all sqlite_value structures
|
|
** using sqlite3_free().
|
|
**
|
|
** If an error occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
|
|
** The apOut[] array may have been partially populated in this case.
|
|
*/
|
|
static int sessionReadRecord(
|
|
u8 **paChange, /* IN/OUT: Pointer to binary record */
|
|
int nCol, /* Number of values in record */
|
|
u8 *abPK, /* Array of primary key flags, or NULL */
|
|
sqlite3_value **apOut /* Write values to this array */
|
|
){
|
|
int i; /* Used to iterate through columns */
|
|
u8 *aRec = *paChange; /* Cursor for the serialized record */
|
|
|
|
for(i=0; i<nCol; i++){
|
|
int eType;
|
|
if( abPK && abPK[i]==0 ) continue;
|
|
eType = *aRec++; /* Type of value (SQLITE_NULL, TEXT etc.) */
|
|
assert( !apOut || apOut[i]==0 );
|
|
if( eType ){
|
|
if( apOut ){
|
|
apOut[i] = sqlite3ValueNew(0);
|
|
if( !apOut[i] ) return SQLITE_NOMEM;
|
|
}
|
|
|
|
if( eType==SQLITE_TEXT || eType==SQLITE_BLOB ){
|
|
int nByte;
|
|
aRec += sessionVarintGet(aRec, &nByte);
|
|
if( apOut ){
|
|
u8 enc = (eType==SQLITE_TEXT ? SQLITE_UTF8 : 0);
|
|
sqlite3ValueSetStr(apOut[i], nByte, (char *)aRec, enc, SQLITE_STATIC);
|
|
}
|
|
aRec += nByte;
|
|
}
|
|
if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){
|
|
if( apOut ){
|
|
sqlite3_int64 v = sessionGetI64(aRec);
|
|
if( eType==SQLITE_INTEGER ){
|
|
sqlite3VdbeMemSetInt64(apOut[i], v);
|
|
}else{
|
|
double d;
|
|
memcpy(&d, &v, 8);
|
|
sqlite3VdbeMemSetDouble(apOut[i], d);
|
|
}
|
|
}
|
|
aRec += 8;
|
|
}
|
|
}
|
|
}
|
|
|
|
*paChange = aRec;
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Advance the changeset iterator to the next change.
|
|
**
|
|
** If both paRec and pnRec are NULL, then this function works like the public
|
|
** API sqlite3changeset_next(). If SQLITE_ROW is returned, then the
|
|
** sqlite3changeset_new() and old() APIs may be used to query for values.
|
|
**
|
|
** Otherwise, if paRec and pnRec are not NULL, then a pointer to the change
|
|
** record is written to *paRec before returning and the number of bytes in
|
|
** the record to *pnRec.
|
|
**
|
|
** Either way, this function returns SQLITE_ROW if the iterator is
|
|
** successfully advanced to the next change in the changeset, an SQLite
|
|
** error code if an error occurs, or SQLITE_DONE if there are no further
|
|
** changes in the changeset.
|
|
*/
|
|
static int sessionChangesetNext(
|
|
sqlite3_changeset_iter *p, /* Changeset iterator */
|
|
u8 **paRec, /* If non-NULL, store record pointer here */
|
|
int *pnRec /* If non-NULL, store size of record here */
|
|
){
|
|
u8 *aChange;
|
|
int i;
|
|
|
|
assert( (paRec==0 && pnRec==0) || (paRec && pnRec) );
|
|
|
|
/* If the iterator is in the error-state, return immediately. */
|
|
if( p->rc!=SQLITE_OK ) return p->rc;
|
|
|
|
/* Free the current contents of p->apValue[], if any. */
|
|
if( p->apValue ){
|
|
for(i=0; i<p->nCol*2; i++){
|
|
sqlite3ValueFree(p->apValue[i]);
|
|
}
|
|
memset(p->apValue, 0, sizeof(sqlite3_value*)*p->nCol*2);
|
|
}
|
|
|
|
/* If the iterator is already at the end of the changeset, return DONE. */
|
|
if( p->pNext>=&p->aChangeset[p->nChangeset] ){
|
|
return SQLITE_DONE;
|
|
}
|
|
aChange = p->pNext;
|
|
|
|
if( aChange[0]=='T' || aChange[0]=='P' ){
|
|
int nByte; /* Bytes to allocate for apValue */
|
|
p->bPatchset = (aChange[0]=='P');
|
|
aChange++;
|
|
aChange += sessionVarintGet(aChange, &p->nCol);
|
|
p->abPK = (u8 *)aChange;
|
|
aChange += p->nCol;
|
|
p->zTab = (char *)aChange;
|
|
aChange += (sqlite3Strlen30((char *)aChange) + 1);
|
|
|
|
if( paRec==0 ){
|
|
sqlite3_free(p->apValue);
|
|
nByte = sizeof(sqlite3_value *) * p->nCol * 2;
|
|
p->apValue = (sqlite3_value **)sqlite3_malloc(nByte);
|
|
if( !p->apValue ){
|
|
return (p->rc = SQLITE_NOMEM);
|
|
}
|
|
memset(p->apValue, 0, sizeof(sqlite3_value*)*p->nCol*2);
|
|
}
|
|
}
|
|
|
|
p->op = *(aChange++);
|
|
p->bIndirect = *(aChange++);
|
|
if( p->op!=SQLITE_UPDATE && p->op!=SQLITE_DELETE && p->op!=SQLITE_INSERT ){
|
|
return (p->rc = SQLITE_CORRUPT);
|
|
}
|
|
|
|
if( paRec ){ *paRec = aChange; }
|
|
|
|
/* If this is an UPDATE or DELETE, read the old.* record. */
|
|
if( p->op!=SQLITE_INSERT && (p->bPatchset==0 || p->op==SQLITE_DELETE) ){
|
|
u8 *abPK = p->bPatchset ? p->abPK : 0;
|
|
p->rc = sessionReadRecord(&aChange, p->nCol, abPK, paRec?0:p->apValue);
|
|
if( p->rc!=SQLITE_OK ) return p->rc;
|
|
}
|
|
|
|
/* If this is an INSERT or UPDATE, read the new.* record. */
|
|
if( p->op!=SQLITE_DELETE ){
|
|
sqlite3_value **apOut = (paRec ? 0 : &p->apValue[p->nCol]);
|
|
p->rc = sessionReadRecord(&aChange, p->nCol, 0, apOut);
|
|
if( p->rc!=SQLITE_OK ) return p->rc;
|
|
}
|
|
|
|
if( pnRec ){
|
|
*pnRec = (int)(aChange - *paRec);
|
|
}else if( p->bPatchset && p->op==SQLITE_UPDATE ){
|
|
/* If this is an UPDATE that is part of a patchset, then all PK and
|
|
** modified fields are present in the new.* record. The old.* record
|
|
** is currently completely empty. This block shifts the PK fields from
|
|
** new.* to old.*, to accommodate the code that reads these arrays. */
|
|
int i;
|
|
for(i=0; i<p->nCol; i++){
|
|
assert( p->apValue[i]==0 );
|
|
assert( p->abPK[i]==0 || p->apValue[i+p->nCol] );
|
|
if( p->abPK[i] ){
|
|
p->apValue[i] = p->apValue[i+p->nCol];
|
|
p->apValue[i+p->nCol] = 0;
|
|
}
|
|
}
|
|
}
|
|
p->pNext = aChange;
|
|
return SQLITE_ROW;
|
|
}
|
|
|
|
/*
|
|
** Advance an iterator created by sqlite3changeset_start() to the next
|
|
** change in the changeset. This function may return SQLITE_ROW, SQLITE_DONE
|
|
** or SQLITE_CORRUPT.
|
|
**
|
|
** This function may not be called on iterators passed to a conflict handler
|
|
** callback by changeset_apply().
|
|
*/
|
|
int sqlite3changeset_next(sqlite3_changeset_iter *p){
|
|
return sessionChangesetNext(p, 0, 0);
|
|
}
|
|
|
|
/*
|
|
** The following function extracts information on the current change
|
|
** from a changeset iterator. It may only be called after changeset_next()
|
|
** has returned SQLITE_ROW.
|
|
*/
|
|
int sqlite3changeset_op(
|
|
sqlite3_changeset_iter *pIter, /* Iterator handle */
|
|
const char **pzTab, /* OUT: Pointer to table name */
|
|
int *pnCol, /* OUT: Number of columns in table */
|
|
int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
|
|
int *pbIndirect /* OUT: True if change is indirect */
|
|
){
|
|
*pOp = pIter->op;
|
|
*pnCol = pIter->nCol;
|
|
*pzTab = pIter->zTab;
|
|
if( pbIndirect ) *pbIndirect = pIter->bIndirect;
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Return information regarding the PRIMARY KEY and number of columns in
|
|
** the database table affected by the change that pIter currently points
|
|
** to. This function may only be called after changeset_next() returns
|
|
** SQLITE_ROW.
|
|
*/
|
|
int sqlite3changeset_pk(
|
|
sqlite3_changeset_iter *pIter, /* Iterator object */
|
|
unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
|
|
int *pnCol /* OUT: Number of entries in output array */
|
|
){
|
|
*pabPK = pIter->abPK;
|
|
if( pnCol ) *pnCol = pIter->nCol;
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** This function may only be called while the iterator is pointing to an
|
|
** SQLITE_UPDATE or SQLITE_DELETE change (see sqlite3changeset_op()).
|
|
** Otherwise, SQLITE_MISUSE is returned.
|
|
**
|
|
** It sets *ppValue to point to an sqlite3_value structure containing the
|
|
** iVal'th value in the old.* record. Or, if that particular value is not
|
|
** included in the record (because the change is an UPDATE and the field
|
|
** was not modified and is not a PK column), set *ppValue to NULL.
|
|
**
|
|
** If value iVal is out-of-range, SQLITE_RANGE is returned and *ppValue is
|
|
** not modified. Otherwise, SQLITE_OK.
|
|
*/
|
|
int sqlite3changeset_old(
|
|
sqlite3_changeset_iter *pIter, /* Changeset iterator */
|
|
int iVal, /* Index of old.* value to retrieve */
|
|
sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
|
|
){
|
|
if( pIter->op!=SQLITE_UPDATE && pIter->op!=SQLITE_DELETE ){
|
|
return SQLITE_MISUSE;
|
|
}
|
|
if( iVal<0 || iVal>=pIter->nCol ){
|
|
return SQLITE_RANGE;
|
|
}
|
|
*ppValue = pIter->apValue[iVal];
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** This function may only be called while the iterator is pointing to an
|
|
** SQLITE_UPDATE or SQLITE_INSERT change (see sqlite3changeset_op()).
|
|
** Otherwise, SQLITE_MISUSE is returned.
|
|
**
|
|
** It sets *ppValue to point to an sqlite3_value structure containing the
|
|
** iVal'th value in the new.* record. Or, if that particular value is not
|
|
** included in the record (because the change is an UPDATE and the field
|
|
** was not modified), set *ppValue to NULL.
|
|
**
|
|
** If value iVal is out-of-range, SQLITE_RANGE is returned and *ppValue is
|
|
** not modified. Otherwise, SQLITE_OK.
|
|
*/
|
|
int sqlite3changeset_new(
|
|
sqlite3_changeset_iter *pIter, /* Changeset iterator */
|
|
int iVal, /* Index of new.* value to retrieve */
|
|
sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
|
|
){
|
|
if( pIter->op!=SQLITE_UPDATE && pIter->op!=SQLITE_INSERT ){
|
|
return SQLITE_MISUSE;
|
|
}
|
|
if( iVal<0 || iVal>=pIter->nCol ){
|
|
return SQLITE_RANGE;
|
|
}
|
|
*ppValue = pIter->apValue[pIter->nCol+iVal];
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** The following two macros are used internally. They are similar to the
|
|
** sqlite3changeset_new() and sqlite3changeset_old() functions, except that
|
|
** they omit all error checking and return a pointer to the requested value.
|
|
*/
|
|
#define sessionChangesetNew(pIter, iVal) (pIter)->apValue[(pIter)->nCol+(iVal)]
|
|
#define sessionChangesetOld(pIter, iVal) (pIter)->apValue[(iVal)]
|
|
|
|
/*
|
|
** This function may only be called with a changeset iterator that has been
|
|
** passed to an SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT
|
|
** conflict-handler function. Otherwise, SQLITE_MISUSE is returned.
|
|
**
|
|
** If successful, *ppValue is set to point to an sqlite3_value structure
|
|
** containing the iVal'th value of the conflicting record.
|
|
**
|
|
** If value iVal is out-of-range or some other error occurs, an SQLite error
|
|
** code is returned. Otherwise, SQLITE_OK.
|
|
*/
|
|
int sqlite3changeset_conflict(
|
|
sqlite3_changeset_iter *pIter, /* Changeset iterator */
|
|
int iVal, /* Index of conflict record value to fetch */
|
|
sqlite3_value **ppValue /* OUT: Value from conflicting row */
|
|
){
|
|
if( !pIter->pConflict ){
|
|
return SQLITE_MISUSE;
|
|
}
|
|
if( iVal<0 || iVal>=sqlite3_column_count(pIter->pConflict) ){
|
|
return SQLITE_RANGE;
|
|
}
|
|
*ppValue = sqlite3_column_value(pIter->pConflict, iVal);
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** This function may only be called with an iterator passed to an
|
|
** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
|
|
** it sets the output variable to the total number of known foreign key
|
|
** violations in the destination database and returns SQLITE_OK.
|
|
**
|
|
** In all other cases this function returns SQLITE_MISUSE.
|
|
*/
|
|
int sqlite3changeset_fk_conflicts(
|
|
sqlite3_changeset_iter *pIter, /* Changeset iterator */
|
|
int *pnOut /* OUT: Number of FK violations */
|
|
){
|
|
if( pIter->pConflict || pIter->apValue ){
|
|
return SQLITE_MISUSE;
|
|
}
|
|
*pnOut = pIter->nCol;
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
|
|
/*
|
|
** Finalize an iterator allocated with sqlite3changeset_start().
|
|
**
|
|
** This function may not be called on iterators passed to a conflict handler
|
|
** callback by changeset_apply().
|
|
*/
|
|
int sqlite3changeset_finalize(sqlite3_changeset_iter *p){
|
|
int i; /* Used to iterate through p->apValue[] */
|
|
int rc = p->rc; /* Return code */
|
|
if( p->apValue ){
|
|
for(i=0; i<p->nCol*2; i++) sqlite3ValueFree(p->apValue[i]);
|
|
}
|
|
sqlite3_free(p->apValue);
|
|
sqlite3_free(p);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Invert a changeset object.
|
|
*/
|
|
int sqlite3changeset_invert(
|
|
int nChangeset, /* Number of bytes in input */
|
|
const void *pChangeset, /* Input changeset */
|
|
int *pnInverted, /* OUT: Number of bytes in output changeset */
|
|
void **ppInverted /* OUT: Inverse of pChangeset */
|
|
){
|
|
int rc = SQLITE_OK; /* Return value */
|
|
u8 *aOut;
|
|
u8 *aIn;
|
|
int i;
|
|
int nCol = 0; /* Number of cols in current table */
|
|
u8 *abPK = 0; /* PK array for current table */
|
|
sqlite3_value **apVal = 0; /* Space for values for UPDATE inversion */
|
|
|
|
/* Zero the output variables in case an error occurs. */
|
|
*ppInverted = 0;
|
|
*pnInverted = 0;
|
|
if( nChangeset==0 ) return SQLITE_OK;
|
|
|
|
aOut = (u8 *)sqlite3_malloc(nChangeset);
|
|
if( !aOut ) return SQLITE_NOMEM;
|
|
aIn = (u8 *)pChangeset;
|
|
|
|
i = 0;
|
|
while( i<nChangeset ){
|
|
u8 eType = aIn[i];
|
|
switch( eType ){
|
|
case 'T': {
|
|
/* A 'table' record consists of:
|
|
**
|
|
** * A constant 'T' character,
|
|
** * Number of columns in said table (a varint),
|
|
** * An array of nCol bytes (abPK),
|
|
** * A nul-terminated table name.
|
|
*/
|
|
int nByte = 1 + sessionVarintGet(&aIn[i+1], &nCol);
|
|
abPK = &aIn[i+nByte];
|
|
nByte += nCol;
|
|
nByte += 1 + sqlite3Strlen30((char *)&aIn[i+nByte]);
|
|
memcpy(&aOut[i], &aIn[i], nByte);
|
|
i += nByte;
|
|
sqlite3_free(apVal);
|
|
apVal = 0;
|
|
break;
|
|
}
|
|
|
|
case SQLITE_INSERT:
|
|
case SQLITE_DELETE: {
|
|
int nByte;
|
|
u8 *aEnd = &aIn[i+2];
|
|
|
|
sessionReadRecord(&aEnd, nCol, 0, 0);
|
|
aOut[i] = (eType==SQLITE_DELETE ? SQLITE_INSERT : SQLITE_DELETE);
|
|
aOut[i+1] = aIn[i+1];
|
|
nByte = (int)(aEnd - &aIn[i+2]);
|
|
memcpy(&aOut[i+2], &aIn[i+2], nByte);
|
|
i += 2 + nByte;
|
|
break;
|
|
}
|
|
|
|
case SQLITE_UPDATE: {
|
|
int iCol;
|
|
int nWrite = 0;
|
|
u8 *aEnd = &aIn[i+2];
|
|
|
|
if( 0==apVal ){
|
|
apVal = (sqlite3_value **)sqlite3_malloc(sizeof(apVal[0])*nCol*2);
|
|
if( 0==apVal ){
|
|
rc = SQLITE_NOMEM;
|
|
goto finished_invert;
|
|
}
|
|
memset(apVal, 0, sizeof(apVal[0])*nCol*2);
|
|
}
|
|
|
|
/* Read the old.* and new.* records for the update change. */
|
|
rc = sessionReadRecord(&aEnd, nCol, 0, &apVal[0]);
|
|
if( rc==SQLITE_OK ){
|
|
rc = sessionReadRecord(&aEnd, nCol, 0, &apVal[nCol]);
|
|
}
|
|
|
|
/* Write the header for the new UPDATE change. Same as the original. */
|
|
aOut[i] = SQLITE_UPDATE;
|
|
aOut[i+1] = aIn[i+1];
|
|
nWrite = 2;
|
|
|
|
/* Write the new old.* record. Consists of the PK columns from the
|
|
** original old.* record, and the other values from the original
|
|
** new.* record. */
|
|
for(iCol=0; rc==SQLITE_OK && iCol<nCol; iCol++){
|
|
sqlite3_value *pVal = apVal[iCol + (abPK[iCol] ? 0 : nCol)];
|
|
rc = sessionSerializeValue(&aOut[i+nWrite], pVal, &nWrite);
|
|
}
|
|
|
|
/* Write the new new.* record. Consists of a copy of all values
|
|
** from the original old.* record, except for the PK columns, which
|
|
** are set to "undefined". */
|
|
for(iCol=0; rc==SQLITE_OK && iCol<nCol; iCol++){
|
|
sqlite3_value *pVal = (abPK[iCol] ? 0 : apVal[iCol]);
|
|
rc = sessionSerializeValue(&aOut[i+nWrite], pVal, &nWrite);
|
|
}
|
|
|
|
for(iCol=0; iCol<nCol*2; iCol++){
|
|
sqlite3ValueFree(apVal[iCol]);
|
|
}
|
|
memset(apVal, 0, sizeof(apVal[0])*nCol*2);
|
|
if( rc!=SQLITE_OK ){
|
|
goto finished_invert;
|
|
}
|
|
|
|
i += nWrite;
|
|
assert( &aIn[i]==aEnd );
|
|
break;
|
|
}
|
|
|
|
default:
|
|
rc = SQLITE_CORRUPT;
|
|
goto finished_invert;
|
|
}
|
|
}
|
|
|
|
assert( rc==SQLITE_OK );
|
|
*pnInverted = nChangeset;
|
|
*ppInverted = (void *)aOut;
|
|
|
|
finished_invert:
|
|
if( rc!=SQLITE_OK ){
|
|
sqlite3_free(aOut);
|
|
}
|
|
sqlite3_free(apVal);
|
|
return rc;
|
|
}
|
|
|
|
typedef struct SessionApplyCtx SessionApplyCtx;
|
|
struct SessionApplyCtx {
|
|
sqlite3 *db;
|
|
sqlite3_stmt *pDelete; /* DELETE statement */
|
|
sqlite3_stmt *pUpdate; /* UPDATE statement */
|
|
sqlite3_stmt *pInsert; /* INSERT statement */
|
|
sqlite3_stmt *pSelect; /* SELECT statement */
|
|
int nCol; /* Size of azCol[] and abPK[] arrays */
|
|
const char **azCol; /* Array of column names */
|
|
u8 *abPK; /* Boolean array - true if column is in PK */
|
|
};
|
|
|
|
/*
|
|
** Formulate a statement to DELETE a row from database db. Assuming a table
|
|
** structure like this:
|
|
**
|
|
** CREATE TABLE x(a, b, c, d, PRIMARY KEY(a, c));
|
|
**
|
|
** The DELETE statement looks like this:
|
|
**
|
|
** DELETE FROM x WHERE a = :1 AND c = :3 AND (:5 OR b IS :2 AND d IS :4)
|
|
**
|
|
** Variable :5 (nCol+1) is a boolean. It should be set to 0 if we require
|
|
** matching b and d values, or 1 otherwise. The second case comes up if the
|
|
** conflict handler is invoked with NOTFOUND and returns CHANGESET_REPLACE.
|
|
**
|
|
** If successful, SQLITE_OK is returned and SessionApplyCtx.pDelete is left
|
|
** pointing to the prepared version of the SQL statement.
|
|
*/
|
|
static int sessionDeleteRow(
|
|
sqlite3 *db, /* Database handle */
|
|
const char *zTab, /* Table name */
|
|
SessionApplyCtx *p /* Session changeset-apply context */
|
|
){
|
|
int i;
|
|
const char *zSep = "";
|
|
int rc = SQLITE_OK;
|
|
SessionBuffer buf = {0, 0, 0};
|
|
int nPk = 0;
|
|
|
|
sessionAppendStr(&buf, "DELETE FROM ", &rc);
|
|
sessionAppendIdent(&buf, zTab, &rc);
|
|
sessionAppendStr(&buf, " WHERE ", &rc);
|
|
|
|
for(i=0; i<p->nCol; i++){
|
|
if( p->abPK[i] ){
|
|
nPk++;
|
|
sessionAppendStr(&buf, zSep, &rc);
|
|
sessionAppendIdent(&buf, p->azCol[i], &rc);
|
|
sessionAppendStr(&buf, " = ?", &rc);
|
|
sessionAppendInteger(&buf, i+1, &rc);
|
|
zSep = " AND ";
|
|
}
|
|
}
|
|
|
|
if( nPk<p->nCol ){
|
|
sessionAppendStr(&buf, " AND (?", &rc);
|
|
sessionAppendInteger(&buf, p->nCol+1, &rc);
|
|
sessionAppendStr(&buf, " OR ", &rc);
|
|
|
|
zSep = "";
|
|
for(i=0; i<p->nCol; i++){
|
|
if( !p->abPK[i] ){
|
|
sessionAppendStr(&buf, zSep, &rc);
|
|
sessionAppendIdent(&buf, p->azCol[i], &rc);
|
|
sessionAppendStr(&buf, " IS ?", &rc);
|
|
sessionAppendInteger(&buf, i+1, &rc);
|
|
zSep = "AND ";
|
|
}
|
|
}
|
|
sessionAppendStr(&buf, ")", &rc);
|
|
}
|
|
|
|
if( rc==SQLITE_OK ){
|
|
rc = sqlite3_prepare_v2(db, (char *)buf.aBuf, buf.nBuf, &p->pDelete, 0);
|
|
}
|
|
sqlite3_free(buf.aBuf);
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Formulate and prepare a statement to UPDATE a row from database db.
|
|
** Assuming a table structure like this:
|
|
**
|
|
** CREATE TABLE x(a, b, c, d, PRIMARY KEY(a, c));
|
|
**
|
|
** The UPDATE statement looks like this:
|
|
**
|
|
** UPDATE x SET
|
|
** a = CASE WHEN ?2 THEN ?3 ELSE a END,
|
|
** b = CASE WHEN ?5 THEN ?6 ELSE b END,
|
|
** c = CASE WHEN ?8 THEN ?9 ELSE c END,
|
|
** d = CASE WHEN ?11 THEN ?12 ELSE d END
|
|
** WHERE a = ?1 AND c = ?7 AND (?13 OR
|
|
** (?5==0 OR b IS ?4) AND (?11==0 OR d IS ?10) AND
|
|
** )
|
|
**
|
|
** For each column in the table, there are three variables to bind:
|
|
**
|
|
** ?(i*3+1) The old.* value of the column, if any.
|
|
** ?(i*3+2) A boolean flag indicating that the value is being modified.
|
|
** ?(i*3+3) The new.* value of the column, if any.
|
|
**
|
|
** Also, a boolean flag that, if set to true, causes the statement to update
|
|
** a row even if the non-PK values do not match. This is required if the
|
|
** conflict-handler is invoked with CHANGESET_DATA and returns
|
|
** CHANGESET_REPLACE. This is variable "?(nCol*3+1)".
|
|
**
|
|
** If successful, SQLITE_OK is returned and SessionApplyCtx.pUpdate is left
|
|
** pointing to the prepared version of the SQL statement.
|
|
*/
|
|
static int sessionUpdateRow(
|
|
sqlite3 *db, /* Database handle */
|
|
const char *zTab, /* Table name */
|
|
SessionApplyCtx *p /* Session changeset-apply context */
|
|
){
|
|
int rc = SQLITE_OK;
|
|
int i;
|
|
const char *zSep = "";
|
|
SessionBuffer buf = {0, 0, 0};
|
|
|
|
/* Append "UPDATE tbl SET " */
|
|
sessionAppendStr(&buf, "UPDATE ", &rc);
|
|
sessionAppendIdent(&buf, zTab, &rc);
|
|
sessionAppendStr(&buf, " SET ", &rc);
|
|
|
|
/* Append the assignments */
|
|
for(i=0; i<p->nCol; i++){
|
|
sessionAppendStr(&buf, zSep, &rc);
|
|
sessionAppendIdent(&buf, p->azCol[i], &rc);
|
|
sessionAppendStr(&buf, " = CASE WHEN ?", &rc);
|
|
sessionAppendInteger(&buf, i*3+2, &rc);
|
|
sessionAppendStr(&buf, " THEN ?", &rc);
|
|
sessionAppendInteger(&buf, i*3+3, &rc);
|
|
sessionAppendStr(&buf, " ELSE ", &rc);
|
|
sessionAppendIdent(&buf, p->azCol[i], &rc);
|
|
sessionAppendStr(&buf, " END", &rc);
|
|
zSep = ", ";
|
|
}
|
|
|
|
/* Append the PK part of the WHERE clause */
|
|
sessionAppendStr(&buf, " WHERE ", &rc);
|
|
for(i=0; i<p->nCol; i++){
|
|
if( p->abPK[i] ){
|
|
sessionAppendIdent(&buf, p->azCol[i], &rc);
|
|
sessionAppendStr(&buf, " = ?", &rc);
|
|
sessionAppendInteger(&buf, i*3+1, &rc);
|
|
sessionAppendStr(&buf, " AND ", &rc);
|
|
}
|
|
}
|
|
|
|
/* Append the non-PK part of the WHERE clause */
|
|
sessionAppendStr(&buf, " (?", &rc);
|
|
sessionAppendInteger(&buf, p->nCol*3+1, &rc);
|
|
sessionAppendStr(&buf, " OR 1", &rc);
|
|
for(i=0; i<p->nCol; i++){
|
|
if( !p->abPK[i] ){
|
|
sessionAppendStr(&buf, " AND (?", &rc);
|
|
sessionAppendInteger(&buf, i*3+2, &rc);
|
|
sessionAppendStr(&buf, "=0 OR ", &rc);
|
|
sessionAppendIdent(&buf, p->azCol[i], &rc);
|
|
sessionAppendStr(&buf, " IS ?", &rc);
|
|
sessionAppendInteger(&buf, i*3+1, &rc);
|
|
sessionAppendStr(&buf, ")", &rc);
|
|
}
|
|
}
|
|
sessionAppendStr(&buf, ")", &rc);
|
|
|
|
if( rc==SQLITE_OK ){
|
|
rc = sqlite3_prepare_v2(db, (char *)buf.aBuf, buf.nBuf, &p->pUpdate, 0);
|
|
}
|
|
sqlite3_free(buf.aBuf);
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Formulate and prepare an SQL statement to query table zTab by primary
|
|
** key. Assuming the following table structure:
|
|
**
|
|
** CREATE TABLE x(a, b, c, d, PRIMARY KEY(a, c));
|
|
**
|
|
** The SELECT statement looks like this:
|
|
**
|
|
** SELECT * FROM x WHERE a = ?1 AND c = ?3
|
|
**
|
|
** If successful, SQLITE_OK is returned and SessionApplyCtx.pSelect is left
|
|
** pointing to the prepared version of the SQL statement.
|
|
*/
|
|
static int sessionSelectRow(
|
|
sqlite3 *db, /* Database handle */
|
|
const char *zTab, /* Table name */
|
|
SessionApplyCtx *p /* Session changeset-apply context */
|
|
){
|
|
return sessionSelectStmt(
|
|
db, "main", zTab, p->nCol, p->azCol, p->abPK, &p->pSelect);
|
|
}
|
|
|
|
/*
|
|
** Formulate and prepare an INSERT statement to add a record to table zTab.
|
|
** For example:
|
|
**
|
|
** INSERT INTO main."zTab" VALUES(?1, ?2, ?3 ...);
|
|
**
|
|
** If successful, SQLITE_OK is returned and SessionApplyCtx.pInsert is left
|
|
** pointing to the prepared version of the SQL statement.
|
|
*/
|
|
static int sessionInsertRow(
|
|
sqlite3 *db, /* Database handle */
|
|
const char *zTab, /* Table name */
|
|
SessionApplyCtx *p /* Session changeset-apply context */
|
|
){
|
|
int rc = SQLITE_OK;
|
|
int i;
|
|
SessionBuffer buf = {0, 0, 0};
|
|
|
|
sessionAppendStr(&buf, "INSERT INTO main.", &rc);
|
|
sessionAppendIdent(&buf, zTab, &rc);
|
|
sessionAppendStr(&buf, " VALUES(?", &rc);
|
|
for(i=1; i<p->nCol; i++){
|
|
sessionAppendStr(&buf, ", ?", &rc);
|
|
}
|
|
sessionAppendStr(&buf, ")", &rc);
|
|
|
|
if( rc==SQLITE_OK ){
|
|
rc = sqlite3_prepare_v2(db, (char *)buf.aBuf, buf.nBuf, &p->pInsert, 0);
|
|
}
|
|
sqlite3_free(buf.aBuf);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** A wrapper around sqlite3_bind_value() that detects an extra problem.
|
|
** See comments in the body of this function for details.
|
|
*/
|
|
static int sessionBindValue(
|
|
sqlite3_stmt *pStmt, /* Statement to bind value to */
|
|
int i, /* Parameter number to bind to */
|
|
sqlite3_value *pVal /* Value to bind */
|
|
){
|
|
int eType = sqlite3_value_type(pVal);
|
|
/* COVERAGE: The (pVal->z==0) branch is never true using current versions
|
|
** of SQLite. If a malloc fails in an sqlite3_value_xxx() function, either
|
|
** the (pVal->z) variable remains as it was or the type of the value is
|
|
** set to SQLITE_NULL. */
|
|
if( (eType==SQLITE_TEXT || eType==SQLITE_BLOB) && pVal->z==0 ){
|
|
/* This condition occurs when an earlier OOM in a call to
|
|
** sqlite3_value_text() or sqlite3_value_blob() (perhaps from within
|
|
** a conflict-handler) has zeroed the pVal->z pointer. Return NOMEM. */
|
|
return SQLITE_NOMEM;
|
|
}
|
|
return sqlite3_bind_value(pStmt, i, pVal);
|
|
}
|
|
|
|
/*
|
|
** Iterator pIter must point to an SQLITE_INSERT entry. This function
|
|
** transfers new.* values from the current iterator entry to statement
|
|
** pStmt. The table being inserted into has nCol columns.
|
|
**
|
|
** New.* value $i 0 from the iterator is bound to variable ($i+1) of
|
|
** statement pStmt. If parameter abPK is NULL, all values from 0 to (nCol-1)
|
|
** are transfered to the statement. Otherwise, if abPK is not NULL, it points
|
|
** to an array nCol elements in size. In this case only those values for
|
|
** which abPK[$i] is true are read from the iterator and bound to the
|
|
** statement.
|
|
**
|
|
** An SQLite error code is returned if an error occurs. Otherwise, SQLITE_OK.
|
|
*/
|
|
static int sessionBindRow(
|
|
sqlite3_changeset_iter *pIter, /* Iterator to read values from */
|
|
int(*xValue)(sqlite3_changeset_iter *, int, sqlite3_value **),
|
|
int nCol, /* Number of columns */
|
|
u8 *abPK, /* If not NULL, bind only if true */
|
|
sqlite3_stmt *pStmt /* Bind values to this statement */
|
|
){
|
|
int i;
|
|
int rc = SQLITE_OK;
|
|
|
|
/* Neither sqlite3changeset_old or sqlite3changeset_new can fail if the
|
|
** argument iterator points to a suitable entry. Make sure that xValue
|
|
** is one of these to guarantee that it is safe to ignore the return
|
|
** in the code below. */
|
|
assert( xValue==sqlite3changeset_old || xValue==sqlite3changeset_new );
|
|
|
|
for(i=0; rc==SQLITE_OK && i<nCol; i++){
|
|
if( !abPK || abPK[i] ){
|
|
sqlite3_value *pVal;
|
|
(void)xValue(pIter, i, &pVal);
|
|
rc = sessionBindValue(pStmt, i+1, pVal);
|
|
}
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** SQL statement pSelect is as generated by the sessionSelectRow() function.
|
|
** This function binds the primary key values from the change that changeset
|
|
** iterator pIter points to to the SELECT and attempts to seek to the table
|
|
** entry. If a row is found, the SELECT statement left pointing at the row
|
|
** and SQLITE_ROW is returned. Otherwise, if no row is found and no error
|
|
** has occured, the statement is reset and SQLITE_OK is returned. If an
|
|
** error occurs, the statement is reset and an SQLite error code is returned.
|
|
**
|
|
** If this function returns SQLITE_ROW, the caller must eventually reset()
|
|
** statement pSelect. If any other value is returned, the statement does
|
|
** not require a reset().
|
|
**
|
|
** If the iterator currently points to an INSERT record, bind values from the
|
|
** new.* record to the SELECT statement. Or, if it points to a DELETE or
|
|
** UPDATE, bind values from the old.* record.
|
|
*/
|
|
static int sessionSeekToRow(
|
|
sqlite3 *db, /* Database handle */
|
|
sqlite3_changeset_iter *pIter, /* Changeset iterator */
|
|
u8 *abPK, /* Primary key flags array */
|
|
sqlite3_stmt *pSelect /* SELECT statement from sessionSelectRow() */
|
|
){
|
|
int rc; /* Return code */
|
|
int nCol; /* Number of columns in table */
|
|
int op; /* Changset operation (SQLITE_UPDATE etc.) */
|
|
const char *zDummy; /* Unused */
|
|
|
|
sqlite3changeset_op(pIter, &zDummy, &nCol, &op, 0);
|
|
rc = sessionBindRow(pIter,
|
|
op==SQLITE_INSERT ? sqlite3changeset_new : sqlite3changeset_old,
|
|
nCol, abPK, pSelect
|
|
);
|
|
|
|
if( rc==SQLITE_OK ){
|
|
rc = sqlite3_step(pSelect);
|
|
if( rc!=SQLITE_ROW ) rc = sqlite3_reset(pSelect);
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Invoke the conflict handler for the change that the changeset iterator
|
|
** currently points to.
|
|
**
|
|
** Argument eType must be either CHANGESET_DATA or CHANGESET_CONFLICT.
|
|
** If argument pbReplace is NULL, then the type of conflict handler invoked
|
|
** depends solely on eType, as follows:
|
|
**
|
|
** eType value Value passed to xConflict
|
|
** -------------------------------------------------
|
|
** CHANGESET_DATA CHANGESET_NOTFOUND
|
|
** CHANGESET_CONFLICT CHANGESET_CONSTRAINT
|
|
**
|
|
** Or, if pbReplace is not NULL, then an attempt is made to find an existing
|
|
** record with the same primary key as the record about to be deleted, updated
|
|
** or inserted. If such a record can be found, it is available to the conflict
|
|
** handler as the "conflicting" record. In this case the type of conflict
|
|
** handler invoked is as follows:
|
|
**
|
|
** eType value PK Record found? Value passed to xConflict
|
|
** ----------------------------------------------------------------
|
|
** CHANGESET_DATA Yes CHANGESET_DATA
|
|
** CHANGESET_DATA No CHANGESET_NOTFOUND
|
|
** CHANGESET_CONFLICT Yes CHANGESET_CONFLICT
|
|
** CHANGESET_CONFLICT No CHANGESET_CONSTRAINT
|
|
**
|
|
** If pbReplace is not NULL, and a record with a matching PK is found, and
|
|
** the conflict handler function returns SQLITE_CHANGESET_REPLACE, *pbReplace
|
|
** is set to non-zero before returning SQLITE_OK.
|
|
**
|
|
** If the conflict handler returns SQLITE_CHANGESET_ABORT, SQLITE_ABORT is
|
|
** returned. Or, if the conflict handler returns an invalid value,
|
|
** SQLITE_MISUSE. If the conflict handler returns SQLITE_CHANGESET_OMIT,
|
|
** this function returns SQLITE_OK.
|
|
*/
|
|
static int sessionConflictHandler(
|
|
int eType, /* Either CHANGESET_DATA or CONFLICT */
|
|
SessionApplyCtx *p, /* changeset_apply() context */
|
|
sqlite3_changeset_iter *pIter, /* Changeset iterator */
|
|
int(*xConflict)(void *, int, sqlite3_changeset_iter*),
|
|
void *pCtx, /* First argument for conflict handler */
|
|
int *pbReplace /* OUT: Set to true if PK row is found */
|
|
){
|
|
int res; /* Value returned by conflict handler */
|
|
int rc;
|
|
int nCol;
|
|
int op;
|
|
const char *zDummy;
|
|
|
|
sqlite3changeset_op(pIter, &zDummy, &nCol, &op, 0);
|
|
|
|
assert( eType==SQLITE_CHANGESET_CONFLICT || eType==SQLITE_CHANGESET_DATA );
|
|
assert( SQLITE_CHANGESET_CONFLICT+1==SQLITE_CHANGESET_CONSTRAINT );
|
|
assert( SQLITE_CHANGESET_DATA+1==SQLITE_CHANGESET_NOTFOUND );
|
|
|
|
/* Bind the new.* PRIMARY KEY values to the SELECT statement. */
|
|
if( pbReplace ){
|
|
rc = sessionSeekToRow(p->db, pIter, p->abPK, p->pSelect);
|
|
}else{
|
|
rc = SQLITE_OK;
|
|
}
|
|
|
|
if( rc==SQLITE_ROW ){
|
|
/* There exists another row with the new.* primary key. */
|
|
pIter->pConflict = p->pSelect;
|
|
res = xConflict(pCtx, eType, pIter);
|
|
pIter->pConflict = 0;
|
|
rc = sqlite3_reset(p->pSelect);
|
|
}else if( rc==SQLITE_OK ){
|
|
/* No other row with the new.* primary key. */
|
|
res = xConflict(pCtx, eType+1, pIter);
|
|
if( res==SQLITE_CHANGESET_REPLACE ) rc = SQLITE_MISUSE;
|
|
}
|
|
|
|
if( rc==SQLITE_OK ){
|
|
switch( res ){
|
|
case SQLITE_CHANGESET_REPLACE:
|
|
assert( pbReplace );
|
|
*pbReplace = 1;
|
|
break;
|
|
|
|
case SQLITE_CHANGESET_OMIT:
|
|
break;
|
|
|
|
case SQLITE_CHANGESET_ABORT:
|
|
rc = SQLITE_ABORT;
|
|
break;
|
|
|
|
default:
|
|
rc = SQLITE_MISUSE;
|
|
break;
|
|
}
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Attempt to apply the change that the iterator passed as the first argument
|
|
** currently points to to the database. If a conflict is encountered, invoke
|
|
** the conflict handler callback.
|
|
**
|
|
** If argument pbRetry is NULL, then ignore any CHANGESET_DATA conflict. If
|
|
** one is encountered, update or delete the row with the matching primary key
|
|
** instead. Or, if pbRetry is not NULL and a CHANGESET_DATA conflict occurs,
|
|
** invoke the conflict handler. If it returns CHANGESET_REPLACE, set *pbRetry
|
|
** to true before returning. In this case the caller will invoke this function
|
|
** again, this time with pbRetry set to NULL.
|
|
**
|
|
** If argument pbReplace is NULL and a CHANGESET_CONFLICT conflict is
|
|
** encountered invoke the conflict handler with CHANGESET_CONSTRAINT instead.
|
|
** Or, if pbReplace is not NULL, invoke it with CHANGESET_CONFLICT. If such
|
|
** an invocation returns SQLITE_CHANGESET_REPLACE, set *pbReplace to true
|
|
** before retrying. In this case the caller attempts to remove the conflicting
|
|
** row before invoking this function again, this time with pbReplace set
|
|
** to NULL.
|
|
**
|
|
** If any conflict handler returns SQLITE_CHANGESET_ABORT, this function
|
|
** returns SQLITE_ABORT. Otherwise, if no error occurs, SQLITE_OK is
|
|
** returned.
|
|
*/
|
|
static int sessionApplyOneOp(
|
|
sqlite3_changeset_iter *pIter, /* Changeset iterator */
|
|
SessionApplyCtx *p, /* changeset_apply() context */
|
|
int(*xConflict)(void *, int, sqlite3_changeset_iter *),
|
|
void *pCtx, /* First argument for the conflict handler */
|
|
int *pbReplace, /* OUT: True to remove PK row and retry */
|
|
int *pbRetry /* OUT: True to retry. */
|
|
){
|
|
const char *zDummy;
|
|
int op;
|
|
int nCol;
|
|
int rc = SQLITE_OK;
|
|
|
|
assert( p->pDelete && p->pUpdate && p->pInsert && p->pSelect );
|
|
assert( p->azCol && p->abPK );
|
|
assert( !pbReplace || *pbReplace==0 );
|
|
|
|
sqlite3changeset_op(pIter, &zDummy, &nCol, &op, 0);
|
|
|
|
if( op==SQLITE_DELETE ){
|
|
|
|
/* Bind values to the DELETE statement. If conflict handling is required,
|
|
** bind values for all columns and set bound variable (nCol+1) to true.
|
|
** Or, if conflict handling is not required, bind just the PK column
|
|
** values and, if it exists, set (nCol+1) to false. Conflict handling
|
|
** is not required if:
|
|
**
|
|
** * this is a patchset, or
|
|
** * (pbRetry==0), or
|
|
** * all columns of the table are PK columns (in this case there is
|
|
** no (nCol+1) variable to bind to).
|
|
*/
|
|
u8 *abPK = (pIter->bPatchset ? p->abPK : 0);
|
|
rc = sessionBindRow(pIter, sqlite3changeset_old, nCol, abPK, p->pDelete);
|
|
if( rc==SQLITE_OK && sqlite3_bind_parameter_count(p->pDelete)>nCol ){
|
|
rc = sqlite3_bind_int(p->pDelete, nCol+1, (pbRetry==0 || abPK));
|
|
}
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
sqlite3_step(p->pDelete);
|
|
rc = sqlite3_reset(p->pDelete);
|
|
if( rc==SQLITE_OK && sqlite3_changes(p->db)==0 ){
|
|
rc = sessionConflictHandler(
|
|
SQLITE_CHANGESET_DATA, p, pIter, xConflict, pCtx, pbRetry
|
|
);
|
|
}else if( (rc&0xff)==SQLITE_CONSTRAINT ){
|
|
rc = sessionConflictHandler(
|
|
SQLITE_CHANGESET_CONFLICT, p, pIter, xConflict, pCtx, 0
|
|
);
|
|
}
|
|
|
|
}else if( op==SQLITE_UPDATE ){
|
|
int i;
|
|
|
|
/* Bind values to the UPDATE statement. */
|
|
for(i=0; rc==SQLITE_OK && i<nCol; i++){
|
|
sqlite3_value *pOld = sessionChangesetOld(pIter, i);
|
|
sqlite3_value *pNew = sessionChangesetNew(pIter, i);
|
|
|
|
sqlite3_bind_int(p->pUpdate, i*3+2, !!pNew);
|
|
if( pOld ){
|
|
rc = sessionBindValue(p->pUpdate, i*3+1, pOld);
|
|
}
|
|
if( rc==SQLITE_OK && pNew ){
|
|
rc = sessionBindValue(p->pUpdate, i*3+3, pNew);
|
|
}
|
|
}
|
|
if( rc==SQLITE_OK ){
|
|
sqlite3_bind_int(p->pUpdate, nCol*3+1, pbRetry==0 || pIter->bPatchset);
|
|
}
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
/* Attempt the UPDATE. In the case of a NOTFOUND or DATA conflict,
|
|
** the result will be SQLITE_OK with 0 rows modified. */
|
|
sqlite3_step(p->pUpdate);
|
|
rc = sqlite3_reset(p->pUpdate);
|
|
|
|
if( rc==SQLITE_OK && sqlite3_changes(p->db)==0 ){
|
|
/* A NOTFOUND or DATA error. Search the table to see if it contains
|
|
** a row with a matching primary key. If so, this is a DATA conflict.
|
|
** Otherwise, if there is no primary key match, it is a NOTFOUND. */
|
|
|
|
rc = sessionConflictHandler(
|
|
SQLITE_CHANGESET_DATA, p, pIter, xConflict, pCtx, pbRetry
|
|
);
|
|
|
|
}else if( (rc&0xff)==SQLITE_CONSTRAINT ){
|
|
/* This is always a CONSTRAINT conflict. */
|
|
rc = sessionConflictHandler(
|
|
SQLITE_CHANGESET_CONFLICT, p, pIter, xConflict, pCtx, 0
|
|
);
|
|
}
|
|
|
|
}else{
|
|
assert( op==SQLITE_INSERT );
|
|
rc = sessionBindRow(pIter, sqlite3changeset_new, nCol, 0, p->pInsert);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
sqlite3_step(p->pInsert);
|
|
rc = sqlite3_reset(p->pInsert);
|
|
if( (rc&0xff)==SQLITE_CONSTRAINT ){
|
|
rc = sessionConflictHandler(
|
|
SQLITE_CHANGESET_CONFLICT, p, pIter, xConflict, pCtx, pbReplace
|
|
);
|
|
}
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Apply the changeset passed via pChangeset/nChangeset to the main database
|
|
** attached to handle "db". Invoke the supplied conflict handler callback
|
|
** to resolve any conflicts encountered while applying the change.
|
|
*/
|
|
int sqlite3changeset_apply(
|
|
sqlite3 *db, /* Apply change to "main" db of this handle */
|
|
int nChangeset, /* Size of changeset in bytes */
|
|
void *pChangeset, /* Changeset blob */
|
|
int(*xFilter)(
|
|
void *pCtx, /* Copy of sixth arg to _apply() */
|
|
const char *zTab /* Table name */
|
|
),
|
|
int(*xConflict)(
|
|
void *pCtx, /* Copy of fifth arg to _apply() */
|
|
int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
|
|
sqlite3_changeset_iter *p /* Handle describing change and conflict */
|
|
),
|
|
void *pCtx /* First argument passed to xConflict */
|
|
){
|
|
int schemaMismatch = 0;
|
|
sqlite3_changeset_iter *pIter; /* Iterator to skip through changeset */
|
|
int rc; /* Return code */
|
|
const char *zTab = 0; /* Name of current table */
|
|
int nTab = 0; /* Result of sqlite3Strlen30(zTab) */
|
|
SessionApplyCtx sApply; /* changeset_apply() context object */
|
|
|
|
assert( xConflict!=0 );
|
|
|
|
memset(&sApply, 0, sizeof(sApply));
|
|
rc = sqlite3changeset_start(&pIter, nChangeset, pChangeset);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
sqlite3_mutex_enter(sqlite3_db_mutex(db));
|
|
rc = sqlite3_exec(db, "SAVEPOINT changeset_apply", 0, 0, 0);
|
|
if( rc==SQLITE_OK ){
|
|
rc = sqlite3_exec(db, "PRAGMA defer_foreign_keys = 1", 0, 0, 0);
|
|
}
|
|
while( rc==SQLITE_OK && SQLITE_ROW==sqlite3changeset_next(pIter) ){
|
|
int nCol;
|
|
int op;
|
|
int bReplace = 0;
|
|
int bRetry = 0;
|
|
const char *zNew;
|
|
|
|
sqlite3changeset_op(pIter, &zNew, &nCol, &op, 0);
|
|
|
|
if( zTab==0 || sqlite3_strnicmp(zNew, zTab, nTab+1) ){
|
|
u8 *abPK;
|
|
|
|
sqlite3_free((char*)sApply.azCol); /* cast works around VC++ bug */
|
|
sqlite3_finalize(sApply.pDelete);
|
|
sqlite3_finalize(sApply.pUpdate);
|
|
sqlite3_finalize(sApply.pInsert);
|
|
sqlite3_finalize(sApply.pSelect);
|
|
memset(&sApply, 0, sizeof(sApply));
|
|
sApply.db = db;
|
|
|
|
/* If an xFilter() callback was specified, invoke it now. If the
|
|
** xFilter callback returns zero, skip this table. If it returns
|
|
** non-zero, proceed. */
|
|
schemaMismatch = (xFilter && (0==xFilter(pCtx, zNew)));
|
|
if( schemaMismatch ){
|
|
zTab = sqlite3_mprintf("%s", zNew);
|
|
nTab = (int)strlen(zTab);
|
|
sApply.azCol = (const char **)zTab;
|
|
}else{
|
|
sqlite3changeset_pk(pIter, &abPK, 0);
|
|
rc = sessionTableInfo(
|
|
db, "main", zNew, &sApply.nCol, &zTab, &sApply.azCol, &sApply.abPK
|
|
);
|
|
if( rc!=SQLITE_OK ) break;
|
|
|
|
if( sApply.nCol==0 ){
|
|
schemaMismatch = 1;
|
|
sqlite3_log(SQLITE_SCHEMA,
|
|
"sqlite3changeset_apply(): no such table: %s", zTab
|
|
);
|
|
}
|
|
else if( sApply.nCol!=nCol ){
|
|
schemaMismatch = 1;
|
|
sqlite3_log(SQLITE_SCHEMA,
|
|
"sqlite3changeset_apply(): table %s has %d columns, expected %d",
|
|
zTab, sApply.nCol, nCol
|
|
);
|
|
}
|
|
else if( memcmp(sApply.abPK, abPK, nCol)!=0 ){
|
|
schemaMismatch = 1;
|
|
sqlite3_log(SQLITE_SCHEMA, "sqlite3changeset_apply(): "
|
|
"primary key mismatch for table %s", zTab
|
|
);
|
|
}
|
|
else if(
|
|
(rc = sessionSelectRow(db, zTab, &sApply))
|
|
|| (rc = sessionUpdateRow(db, zTab, &sApply))
|
|
|| (rc = sessionDeleteRow(db, zTab, &sApply))
|
|
|| (rc = sessionInsertRow(db, zTab, &sApply))
|
|
){
|
|
break;
|
|
}
|
|
nTab = sqlite3Strlen30(zTab);
|
|
}
|
|
}
|
|
|
|
/* If there is a schema mismatch on the current table, proceed to the
|
|
** next change. A log message has already been issued. */
|
|
if( schemaMismatch ) continue;
|
|
|
|
rc = sessionApplyOneOp(pIter, &sApply, xConflict, pCtx, &bReplace, &bRetry);
|
|
|
|
if( rc==SQLITE_OK && bRetry ){
|
|
rc = sessionApplyOneOp(pIter, &sApply, xConflict, pCtx, &bReplace, 0);
|
|
}
|
|
|
|
if( bReplace ){
|
|
assert( pIter->op==SQLITE_INSERT );
|
|
rc = sqlite3_exec(db, "SAVEPOINT replace_op", 0, 0, 0);
|
|
if( rc==SQLITE_OK ){
|
|
rc = sessionBindRow(pIter,
|
|
sqlite3changeset_new, sApply.nCol, sApply.abPK, sApply.pDelete);
|
|
sqlite3_bind_int(sApply.pDelete, sApply.nCol+1, 1);
|
|
}
|
|
if( rc==SQLITE_OK ){
|
|
sqlite3_step(sApply.pDelete);
|
|
rc = sqlite3_reset(sApply.pDelete);
|
|
}
|
|
if( rc==SQLITE_OK ){
|
|
rc = sessionApplyOneOp(pIter, &sApply, xConflict, pCtx, 0, 0);
|
|
}
|
|
if( rc==SQLITE_OK ){
|
|
rc = sqlite3_exec(db, "RELEASE replace_op", 0, 0, 0);
|
|
}
|
|
}
|
|
}
|
|
|
|
if( rc==SQLITE_OK ){
|
|
rc = sqlite3changeset_finalize(pIter);
|
|
}else{
|
|
sqlite3changeset_finalize(pIter);
|
|
}
|
|
|
|
if( rc==SQLITE_OK ){
|
|
int nFk, notUsed;
|
|
sqlite3_db_status(db, SQLITE_DBSTATUS_DEFERRED_FKS, &nFk, ¬Used, 0);
|
|
if( nFk!=0 ){
|
|
int res = SQLITE_CHANGESET_ABORT;
|
|
sqlite3_changeset_iter sIter;
|
|
memset(&sIter, 0, sizeof(sIter));
|
|
sIter.nCol = nFk;
|
|
res = xConflict(pCtx, SQLITE_CHANGESET_FOREIGN_KEY, &sIter);
|
|
if( res!=SQLITE_CHANGESET_OMIT ){
|
|
rc = SQLITE_CONSTRAINT;
|
|
}
|
|
}
|
|
}
|
|
sqlite3_exec(db, "PRAGMA defer_foreign_keys = 0", 0, 0, 0);
|
|
|
|
if( rc==SQLITE_OK ){
|
|
rc = sqlite3_exec(db, "RELEASE changeset_apply", 0, 0, 0);
|
|
}else{
|
|
sqlite3_exec(db, "ROLLBACK TO changeset_apply", 0, 0, 0);
|
|
sqlite3_exec(db, "RELEASE changeset_apply", 0, 0, 0);
|
|
}
|
|
|
|
sqlite3_finalize(sApply.pInsert);
|
|
sqlite3_finalize(sApply.pDelete);
|
|
sqlite3_finalize(sApply.pUpdate);
|
|
sqlite3_finalize(sApply.pSelect);
|
|
sqlite3_free((char*)sApply.azCol); /* cast works around VC++ bug */
|
|
sqlite3_mutex_leave(sqlite3_db_mutex(db));
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** This function is called to merge two changes to the same row together as
|
|
** part of an sqlite3changeset_concat() operation. A new change object is
|
|
** allocated and a pointer to it stored in *ppNew.
|
|
*/
|
|
static int sessionChangeMerge(
|
|
SessionTable *pTab, /* Table structure */
|
|
int bPatchset, /* True for patchsets */
|
|
SessionChange *pExist, /* Existing change */
|
|
int op2, /* Second change operation */
|
|
int bIndirect, /* True if second change is indirect */
|
|
u8 *aRec, /* Second change record */
|
|
int nRec, /* Number of bytes in aRec */
|
|
SessionChange **ppNew /* OUT: Merged change */
|
|
){
|
|
SessionChange *pNew = 0;
|
|
|
|
if( !pExist ){
|
|
pNew = (SessionChange *)sqlite3_malloc(sizeof(SessionChange));
|
|
if( !pNew ){
|
|
return SQLITE_NOMEM;
|
|
}
|
|
memset(pNew, 0, sizeof(SessionChange));
|
|
pNew->op = op2;
|
|
pNew->bIndirect = bIndirect;
|
|
pNew->nRecord = nRec;
|
|
pNew->aRecord = aRec;
|
|
}else{
|
|
int op1 = pExist->op;
|
|
|
|
/*
|
|
** op1=INSERT, op2=INSERT -> Unsupported. Discard op2.
|
|
** op1=INSERT, op2=UPDATE -> INSERT.
|
|
** op1=INSERT, op2=DELETE -> (none)
|
|
**
|
|
** op1=UPDATE, op2=INSERT -> Unsupported. Discard op2.
|
|
** op1=UPDATE, op2=UPDATE -> UPDATE.
|
|
** op1=UPDATE, op2=DELETE -> DELETE.
|
|
**
|
|
** op1=DELETE, op2=INSERT -> UPDATE.
|
|
** op1=DELETE, op2=UPDATE -> Unsupported. Discard op2.
|
|
** op1=DELETE, op2=DELETE -> Unsupported. Discard op2.
|
|
*/
|
|
if( (op1==SQLITE_INSERT && op2==SQLITE_INSERT)
|
|
|| (op1==SQLITE_UPDATE && op2==SQLITE_INSERT)
|
|
|| (op1==SQLITE_DELETE && op2==SQLITE_UPDATE)
|
|
|| (op1==SQLITE_DELETE && op2==SQLITE_DELETE)
|
|
){
|
|
pNew = pExist;
|
|
}else if( op1==SQLITE_INSERT && op2==SQLITE_DELETE ){
|
|
sqlite3_free(pExist);
|
|
assert( pNew==0 );
|
|
}else{
|
|
u8 *aExist = pExist->aRecord;
|
|
int nByte;
|
|
u8 *aCsr;
|
|
|
|
/* Allocate a new SessionChange object. Ensure that the aRecord[]
|
|
** buffer of the new object is large enough to hold any record that
|
|
** may be generated by combining the input records. */
|
|
nByte = sizeof(SessionChange) + pExist->nRecord + nRec;
|
|
pNew = (SessionChange *)sqlite3_malloc(nByte);
|
|
if( !pNew ){
|
|
sqlite3_free(pExist);
|
|
return SQLITE_NOMEM;
|
|
}
|
|
memset(pNew, 0, sizeof(SessionChange));
|
|
pNew->bIndirect = (bIndirect && pExist->bIndirect);
|
|
aCsr = pNew->aRecord = (u8 *)&pNew[1];
|
|
|
|
if( op1==SQLITE_INSERT ){ /* INSERT + UPDATE */
|
|
u8 *a1 = aRec;
|
|
assert( op2==SQLITE_UPDATE );
|
|
pNew->op = SQLITE_INSERT;
|
|
if( bPatchset==0 ) sessionReadRecord(&a1, pTab->nCol, 0, 0);
|
|
sessionMergeRecord(&aCsr, pTab->nCol, aExist, a1);
|
|
}else if( op1==SQLITE_DELETE ){ /* DELETE + INSERT */
|
|
assert( op2==SQLITE_INSERT );
|
|
pNew->op = SQLITE_UPDATE;
|
|
if( 0==sessionMergeUpdate(&aCsr, pTab, bPatchset, aExist, 0, aRec, 0) ){
|
|
sqlite3_free(pNew);
|
|
pNew = 0;
|
|
}
|
|
}else if( op2==SQLITE_UPDATE ){ /* UPDATE + UPDATE */
|
|
u8 *a1 = aExist;
|
|
u8 *a2 = aRec;
|
|
assert( op1==SQLITE_UPDATE );
|
|
if( bPatchset==0 ){
|
|
sessionReadRecord(&a1, pTab->nCol, 0, 0);
|
|
sessionReadRecord(&a2, pTab->nCol, 0, 0);
|
|
}
|
|
pNew->op = SQLITE_UPDATE;
|
|
if( 0==sessionMergeUpdate(&aCsr, pTab, bPatchset, aRec, aExist,a1,a2) ){
|
|
sqlite3_free(pNew);
|
|
pNew = 0;
|
|
}
|
|
}else{ /* UPDATE + DELETE */
|
|
assert( op1==SQLITE_UPDATE && op2==SQLITE_DELETE );
|
|
pNew->op = SQLITE_DELETE;
|
|
if( bPatchset ){
|
|
memcpy(aCsr, aRec, nRec);
|
|
aCsr += nRec;
|
|
}else{
|
|
sessionMergeRecord(&aCsr, pTab->nCol, aRec, aExist);
|
|
}
|
|
}
|
|
|
|
if( pNew ){
|
|
pNew->nRecord = (int)(aCsr - pNew->aRecord);
|
|
}
|
|
sqlite3_free(pExist);
|
|
}
|
|
}
|
|
|
|
*ppNew = pNew;
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Add all changes in the changeset passed via the first two arguments to
|
|
** hash tables.
|
|
*/
|
|
static int sessionConcatChangeset(
|
|
int bPatchset, /* True to expect patchsets */
|
|
int nChangeset, /* Number of bytes in pChangeset */
|
|
void *pChangeset, /* Changeset buffer */
|
|
SessionTable **ppTabList /* IN/OUT: List of table objects */
|
|
){
|
|
u8 *aRec;
|
|
int nRec;
|
|
sqlite3_changeset_iter *pIter;
|
|
int rc;
|
|
SessionTable *pTab = 0;
|
|
|
|
rc = sqlite3changeset_start(&pIter, nChangeset, pChangeset);
|
|
if( rc!=SQLITE_OK ) return rc;
|
|
|
|
while( SQLITE_ROW==sessionChangesetNext(pIter, &aRec, &nRec) ){
|
|
const char *zNew;
|
|
int nCol;
|
|
int op;
|
|
int iHash;
|
|
int bIndirect;
|
|
SessionChange *pChange;
|
|
SessionChange *pExist = 0;
|
|
SessionChange **pp;
|
|
|
|
assert( bPatchset==0 || bPatchset==1 );
|
|
assert( pIter->bPatchset==0 || pIter->bPatchset==1 );
|
|
if( pIter->bPatchset!=bPatchset ){
|
|
rc = SQLITE_ERROR;
|
|
break;
|
|
}
|
|
|
|
assert( pIter->apValue==0 );
|
|
sqlite3changeset_op(pIter, &zNew, &nCol, &op, &bIndirect);
|
|
|
|
assert( zNew>=(char *)pChangeset && zNew-nChangeset<((char *)pChangeset) );
|
|
assert( !pTab || pTab->zName-nChangeset<(char *)pChangeset );
|
|
assert( !pTab || zNew>=pTab->zName );
|
|
|
|
if( !pTab || zNew!=pTab->zName ){
|
|
/* Search the list for a matching table */
|
|
int nNew = (int)strlen(zNew);
|
|
u8 *abPK;
|
|
|
|
sqlite3changeset_pk(pIter, &abPK, 0);
|
|
for(pTab = *ppTabList; pTab; pTab=pTab->pNext){
|
|
if( 0==sqlite3_strnicmp(pTab->zName, zNew, nNew+1) ) break;
|
|
}
|
|
if( !pTab ){
|
|
pTab = sqlite3_malloc(sizeof(SessionTable));
|
|
if( !pTab ){
|
|
rc = SQLITE_NOMEM;
|
|
break;
|
|
}
|
|
memset(pTab, 0, sizeof(SessionTable));
|
|
pTab->pNext = *ppTabList;
|
|
pTab->abPK = abPK;
|
|
pTab->nCol = nCol;
|
|
*ppTabList = pTab;
|
|
}else if( pTab->nCol!=nCol || memcmp(pTab->abPK, abPK, nCol) ){
|
|
rc = SQLITE_SCHEMA;
|
|
break;
|
|
}
|
|
pTab->zName = (char *)zNew;
|
|
}
|
|
|
|
if( sessionGrowHash(bPatchset, pTab) ){
|
|
rc = SQLITE_NOMEM;
|
|
break;
|
|
}
|
|
iHash = sessionChangeHash(
|
|
pTab, (bPatchset && op==SQLITE_DELETE), aRec, pTab->nChange
|
|
);
|
|
|
|
/* Search for existing entry. If found, remove it from the hash table.
|
|
** Code below may link it back in.
|
|
*/
|
|
for(pp=&pTab->apChange[iHash]; *pp; pp=&(*pp)->pNext){
|
|
int bPkOnly1 = 0;
|
|
int bPkOnly2 = 0;
|
|
if( bPatchset ){
|
|
bPkOnly1 = (*pp)->op==SQLITE_DELETE;
|
|
bPkOnly2 = op==SQLITE_DELETE;
|
|
}
|
|
if( sessionChangeEqual(pTab, bPkOnly1, (*pp)->aRecord, bPkOnly2, aRec) ){
|
|
pExist = *pp;
|
|
*pp = (*pp)->pNext;
|
|
pTab->nEntry--;
|
|
break;
|
|
}
|
|
}
|
|
|
|
rc = sessionChangeMerge(pTab,
|
|
bPatchset, pExist, op, bIndirect, aRec, nRec, &pChange
|
|
);
|
|
if( rc ) break;
|
|
if( pChange ){
|
|
pChange->pNext = pTab->apChange[iHash];
|
|
pTab->apChange[iHash] = pChange;
|
|
pTab->nEntry++;
|
|
}
|
|
}
|
|
|
|
if( rc==SQLITE_OK ){
|
|
rc = sqlite3changeset_finalize(pIter);
|
|
}else{
|
|
sqlite3changeset_finalize(pIter);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
|
|
/*
|
|
** 1. Iterate through the left-hand changeset. Add an entry to a table
|
|
** specific hash table for each change in the changeset. The hash table
|
|
** key is the PK of the row affected by the change.
|
|
**
|
|
** 2. Then interate through the right-hand changeset. Attempt to add an
|
|
** entry to a hash table for each component change. If a change already
|
|
** exists with the same PK values, combine the two into a single change.
|
|
**
|
|
** 3. Write an output changeset based on the contents of the hash table.
|
|
*/
|
|
int sqlite3changeset_concat(
|
|
int nLeft, /* Number of bytes in lhs input */
|
|
void *pLeft, /* Lhs input changeset */
|
|
int nRight /* Number of bytes in rhs input */,
|
|
void *pRight, /* Rhs input changeset */
|
|
int *pnOut, /* OUT: Number of bytes in output changeset */
|
|
void **ppOut /* OUT: changeset (left <concat> right) */
|
|
){
|
|
SessionTable *pList = 0; /* List of SessionTable objects */
|
|
int rc; /* Return code */
|
|
int bPatch; /* True for a patchset */
|
|
|
|
*pnOut = 0;
|
|
*ppOut = 0;
|
|
bPatch = (nLeft>0 && *(char*)pLeft=='P') || (nRight>0 && *(char*)pRight=='P');
|
|
|
|
rc = sessionConcatChangeset(bPatch, nLeft, pLeft, &pList);
|
|
if( rc==SQLITE_OK ){
|
|
rc = sessionConcatChangeset(bPatch, nRight, pRight, &pList);
|
|
}
|
|
|
|
/* Create the serialized output changeset based on the contents of the
|
|
** hash tables attached to the SessionTable objects in list pList.
|
|
*/
|
|
if( rc==SQLITE_OK ){
|
|
SessionTable *pTab;
|
|
SessionBuffer buf = {0, 0, 0};
|
|
for(pTab=pList; pTab; pTab=pTab->pNext){
|
|
int i;
|
|
if( pTab->nEntry==0 ) continue;
|
|
|
|
sessionAppendTableHdr(&buf, bPatch, pTab, &rc);
|
|
for(i=0; i<pTab->nChange; i++){
|
|
SessionChange *p;
|
|
for(p=pTab->apChange[i]; p; p=p->pNext){
|
|
sessionAppendByte(&buf, p->op, &rc);
|
|
sessionAppendByte(&buf, p->bIndirect, &rc);
|
|
sessionAppendBlob(&buf, p->aRecord, p->nRecord, &rc);
|
|
}
|
|
}
|
|
}
|
|
|
|
if( rc==SQLITE_OK ){
|
|
*ppOut = buf.aBuf;
|
|
*pnOut = buf.nBuf;
|
|
}else{
|
|
sqlite3_free(buf.aBuf);
|
|
}
|
|
}
|
|
|
|
sessionDeleteTable(pList);
|
|
return rc;
|
|
}
|
|
|
|
#endif /* SQLITE_ENABLE_SESSION && SQLITE_ENABLE_PREUPDATE_HOOK */
|