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sqlite/src/sqliteInt.h
drh b19a2bc603 Disclaimed copyright. Preparing for release 2.0. (CVS 250) 
FossilOrigin-Name: 4e926efe2b59adfec4086eb1d2ba830238facb4c
2001-09-16 00:13:26 +00:00

462 lines
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C
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/*
** 2001 September 15
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.51 2001/09/16 00:13:27 drh Exp $
*/
#include "sqlite.h"
#include "vdbe.h"
#include "parse.h"
#include "btree.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
/*
** The maximum number of in-memory pages to use for the main database
** table and for temporary tables.
*/
#define MAX_PAGES 100
#define TEMP_PAGES 25
/*
** Integers of known sizes. These typedefs much change for architectures
** where the sizes very.
*/
typedef unsigned int u32; /* 4-byte unsigned integer */
typedef unsigned short int u16; /* 2-byte unsigned integer */
typedef unsigned char u8; /* 1-byte unsigned integer */
/*
** The maximum number of bytes of data that can be put into a single
** row of a single table.
*/
#define MAX_BYTES_PER_ROW 65535
/*
** If memory allocation problems are found, recompile with
**
** -DMEMORY_DEBUG=1
**
** to enable some sanity checking on malloc() and free(). To
** check for memory leaks, recompile with
**
** -DMEMORY_DEBUG=2
**
** and a line of text will be written to standard error for
** each malloc() and free(). This output can be analyzed
** by an AWK script to determine if there are any leaks.
*/
#ifdef MEMORY_DEBUG
# define sqliteMalloc(X) sqliteMalloc_(X,__FILE__,__LINE__)
# define sqliteFree(X) sqliteFree_(X,__FILE__,__LINE__)
# define sqliteRealloc(X,Y) sqliteRealloc_(X,Y,__FILE__,__LINE__)
# define sqliteStrDup(X) sqliteStrDup_(X,__FILE__,__LINE__)
# define sqliteStrNDup(X,Y) sqliteStrNDup_(X,Y,__FILE__,__LINE__)
void sqliteStrRealloc(char**);
#else
# define sqliteStrRealloc(X)
#endif
/*
** This variable gets set if malloc() ever fails. After it gets set,
** the SQLite library shuts down permanently.
*/
extern int sqlite_malloc_failed;
/*
** The following global variables are used for testing and debugging
** only. They only work if MEMORY_DEBUG is defined.
*/
#ifdef MEMORY_DEBUG
extern int sqlite_nMalloc; /* Number of sqliteMalloc() calls */
extern int sqlite_nFree; /* Number of sqliteFree() calls */
extern int sqlite_iMallocFail; /* Fail sqliteMalloc() after this many calls */
#endif
/*
** The number of entries in the in-memory hash array holding the
** database schema. (Collision resolution is by chaining, so the
** table will hold more than this many entries.)
*/
#define N_HASH 51
/*
** Name of the master database table. The master database table
** is a special table that holds the names and attributes of all
** user tables and indices.
*/
#define MASTER_NAME "sqlite_master"
/*
** A convenience macro that returns the number of elements in
** an array.
*/
#define ArraySize(X) (sizeof(X)/sizeof(X[0]))
/*
** Integer identifiers for built-in SQL functions.
*/
#define FN_Unknown 0
#define FN_Count 1
#define FN_Min 2
#define FN_Max 3
#define FN_Sum 4
#define FN_Avg 5
#define FN_Fcnt 6
#define FN_Length 7
#define FN_Substr 8
/*
** Forward references to structures
*/
typedef struct Column Column;
typedef struct Table Table;
typedef struct Index Index;
typedef struct Instruction Instruction;
typedef struct Expr Expr;
typedef struct ExprList ExprList;
typedef struct Parse Parse;
typedef struct Token Token;
typedef struct IdList IdList;
typedef struct WhereInfo WhereInfo;
typedef struct Select Select;
typedef struct AggExpr AggExpr;
/*
** Each database is an instance of the following structure
*/
struct sqlite {
Btree *pBe; /* The B*Tree backend */
int flags; /* Miscellanous flags. See below */
int file_format; /* What file format version is this database? */
int schema_cookie; /* Magic number that changes with the schema */
int next_cookie; /* Value of schema_cookie after commit */
int nTable; /* Number of tables in the database */
void *pBusyArg; /* 1st Argument to the busy callback */
int (*xBusyCallback)(void *,const char*,int); /* The busy callback */
Table *apTblHash[N_HASH]; /* All tables of the database */
Index *apIdxHash[N_HASH]; /* All indices of the database */
};
/*
** Possible values for the sqlite.flags.
*/
#define SQLITE_VdbeTrace 0x00000001 /* True to trace VDBE execution */
#define SQLITE_Initialized 0x00000002 /* True after initialization */
#define SQLITE_Interrupt 0x00000004 /* Cancel current operation */
#define SQLITE_InTrans 0x00000008 /* True if in a transaction */
#define SQLITE_InternChanges 0x00000010 /* Uncommitted Hash table changes */
/*
** Current file format version
*/
#define SQLITE_FileFormat 2
/*
** information about each column of an SQL table is held in an instance
** of this structure.
*/
struct Column {
char *zName; /* Name of this column */
char *zDflt; /* Default value of this column */
int notNull; /* True if there is a NOT NULL constraint */
};
/*
** Each SQL table is represented in memory by
** an instance of the following structure.
*/
struct Table {
char *zName; /* Name of the table */
Table *pHash; /* Next table with same hash on zName */
int nCol; /* Number of columns in this table */
Column *aCol; /* Information about each column */
Index *pIndex; /* List of SQL indexes on this table. */
int tnum; /* Page containing root for this table */
int readOnly; /* True if this table should not be written by the user */
int isCommit; /* True if creation of this table has been committed */
int isDelete; /* True if this table is being deleted */
};
/*
** Each SQL index is represented in memory by an
** instance of the following structure.
**
** The columns of the table that are to be indexed are described
** by the aiColumn[] field of this structure. For example, suppose
** we have the following table and index:
**
** CREATE TABLE Ex1(c1 int, c2 int, c3 text);
** CREATE INDEX Ex2 ON Ex1(c3,c1);
**
** In the Table structure describing Ex1, nCol==3 because there are
** three columns in the table. In the Index structure describing
** Ex2, nColumn==2 since 2 of the 3 columns of Ex1 are indexed.
** The value of aiColumn is {2, 0}. aiColumn[0]==2 because the
** first column to be indexed (c3) has an index of 2 in Ex1.aCol[].
** The second column to be indexed (c1) has an index of 0 in
** Ex1.aCol[], hence Ex2.aiColumn[1]==0.
*/
struct Index {
char *zName; /* Name of this index */
Index *pHash; /* Next index with the same hash on zName */
int nColumn; /* Number of columns in the table used by this index */
int *aiColumn; /* Which columns are used by this index. 1st is 0 */
Table *pTable; /* The SQL table being indexed */
int tnum; /* Page containing root of this index in database file */
int isUnique; /* True if keys must all be unique */
int isCommit; /* True if creation of this index has been committed */
int isDelete; /* True if deletion of this index has not been comitted */
Index *pNext; /* The next index associated with the same table */
};
/*
** Each token coming out of the lexer is an instance of
** this structure.
*/
struct Token {
char *z; /* Text of the token. Not NULL-terminated! */
int n; /* Number of characters in this token */
};
/*
** Each node of an expression in the parse tree is an instance
** of this structure
*/
struct Expr {
int op; /* Operation performed by this node */
Expr *pLeft, *pRight; /* Left and right subnodes */
ExprList *pList; /* A list of expressions used as a function argument */
Token token; /* An operand token */
Token span; /* Complete text of the expression */
int iTable, iColumn; /* When op==TK_COLUMN, then this expr node means the
** iColumn-th field of the iTable-th table. When
** op==TK_FUNCTION, iColumn holds the function id */
int iAgg; /* When op==TK_COLUMN and pParse->useAgg==TRUE, pull
** result from the iAgg-th element of the aggregator */
Select *pSelect; /* When the expression is a sub-select */
};
/*
** A list of expressions. Each expression may optionally have a
** name. An expr/name combination can be used in several ways, such
** as the list of "expr AS ID" fields following a "SELECT" or in the
** list of "ID = expr" items in an UPDATE. A list of expressions can
** also be used as the argument to a function, in which case the azName
** field is not used.
*/
struct ExprList {
int nExpr; /* Number of expressions on the list */
struct {
Expr *pExpr; /* The list of expressions */
char *zName; /* Token associated with this expression */
char sortOrder; /* 1 for DESC or 0 for ASC */
char isAgg; /* True if this is an aggregate like count(*) */
char done; /* A flag to indicate when processing is finished */
} *a; /* One entry for each expression */
};
/*
** A list of identifiers.
*/
struct IdList {
int nId; /* Number of identifiers on the list */
struct {
char *zName; /* Text of the identifier. */
char *zAlias; /* The "B" part of a "A AS B" phrase. zName is the "A" */
int idx; /* Index in some Table.aCol[] of a column named zName */
Table *pTab; /* An SQL table corresponding to zName */
Select *pSelect; /* A SELECT statement used in place of a table name */
} *a; /* One entry for each identifier on the list */
};
/*
** The WHERE clause processing routine has two halves. The
** first part does the start of the WHERE loop and the second
** half does the tail of the WHERE loop. An instance of
** this structure is returned by the first half and passed
** into the second half to give some continuity.
*/
struct WhereInfo {
Parse *pParse;
IdList *pTabList; /* List of tables in the join */
int iContinue; /* Jump here to continue with next record */
int iBreak; /* Jump here to break out of the loop */
int base; /* Index of first Open opcode */
Index *aIdx[32]; /* Indices used for each table */
};
/*
** An instance of the following structure contains all information
** needed to generate code for a single SELECT statement.
*/
struct Select {
int isDistinct; /* True if the DISTINCT keyword is present */
ExprList *pEList; /* The fields of the result */
IdList *pSrc; /* The FROM clause */
Expr *pWhere; /* The WHERE clause */
ExprList *pGroupBy; /* The GROUP BY clause */
Expr *pHaving; /* The HAVING clause */
ExprList *pOrderBy; /* The ORDER BY clause */
int op; /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */
Select *pPrior; /* Prior select in a compound select statement */
};
/*
** The results of a select can be distributed in several ways.
*/
#define SRT_Callback 1 /* Invoke a callback with each row of result */
#define SRT_Mem 2 /* Store result in a memory cell */
#define SRT_Set 3 /* Store result as unique keys in a table */
#define SRT_Union 5 /* Store result as keys in a table */
#define SRT_Except 6 /* Remove result from a UNION table */
#define SRT_Table 7 /* Store result as data with a unique key */
/*
** When a SELECT uses aggregate functions (like "count(*)" or "avg(f1)")
** we have to do some additional analysis of expressions. An instance
** of the following structure holds information about a single subexpression
** somewhere in the SELECT statement. An array of these structures holds
** all the information we need to generate code for aggregate
** expressions.
**
** Note that when analyzing a SELECT containing aggregates, both
** non-aggregate field variables and aggregate functions are stored
** in the AggExpr array of the Parser structure.
**
** The pExpr field points to an expression that is part of either the
** field list, the GROUP BY clause, the HAVING clause or the ORDER BY
** clause. The expression will be freed when those clauses are cleaned
** up. Do not try to delete the expression attached to AggExpr.pExpr.
**
** If AggExpr.pExpr==0, that means the expression is "count(*)".
*/
struct AggExpr {
int isAgg; /* if TRUE contains an aggregate function */
Expr *pExpr; /* The expression */
};
/*
** An SQL parser context
*/
struct Parse {
sqlite *db; /* The main database structure */
Btree *pBe; /* The database backend */
int rc; /* Return code from execution */
sqlite_callback xCallback; /* The callback function */
void *pArg; /* First argument to the callback function */
char *zErrMsg; /* An error message */
Token sErrToken; /* The token at which the error occurred */
Token sFirstToken; /* The first token parsed */
Token sLastToken; /* The last token parsed */
Table *pNewTable; /* A table being constructed by CREATE TABLE */
Vdbe *pVdbe; /* An engine for executing database bytecode */
int colNamesSet; /* TRUE after OP_ColumnCount has been issued to pVdbe */
int explain; /* True if the EXPLAIN flag is found on the query */
int initFlag; /* True if reparsing CREATE TABLEs */
int newTnum; /* Table number to use when reparsing CREATE TABLEs */
int nErr; /* Number of errors seen */
int nTab; /* Number of previously allocated cursors */
int nMem; /* Number of memory cells used so far */
int nSet; /* Number of sets used so far */
int nAgg; /* Number of aggregate expressions */
AggExpr *aAgg; /* An array of aggregate expressions */
int iAggCount; /* Index of the count(*) aggregate in aAgg[] */
int useAgg; /* If true, extract field values from the aggregator
** while generating expressions. Normally false */
int schemaVerified; /* True if an OP_VerifySchema has been coded someplace
** other than after an OP_Transaction */
};
/*
** Internal function prototypes
*/
int sqliteStrICmp(const char *, const char *);
int sqliteStrNICmp(const char *, const char *, int);
int sqliteHashNoCase(const char *, int);
int sqliteCompare(const char *, const char *);
int sqliteSortCompare(const char *, const char *);
#ifdef MEMORY_DEBUG
void *sqliteMalloc_(int,char*,int);
void sqliteFree_(void*,char*,int);
void *sqliteRealloc_(void*,int,char*,int);
char *sqliteStrDup_(const char*,char*,int);
char *sqliteStrNDup_(const char*, int,char*,int);
#else
void *sqliteMalloc(int);
void sqliteFree(void*);
void *sqliteRealloc(void*,int);
char *sqliteStrDup(const char*);
char *sqliteStrNDup(const char*, int);
#endif
int sqliteGetToken(const char*, int *);
void sqliteSetString(char **, const char *, ...);
void sqliteSetNString(char **, ...);
void sqliteDequote(char*);
int sqliteRunParser(Parse*, char*, char **);
void sqliteExec(Parse*);
Expr *sqliteExpr(int, Expr*, Expr*, Token*);
void sqliteExprSpan(Expr*,Token*,Token*);
Expr *sqliteExprFunction(ExprList*, Token*);
void sqliteExprDelete(Expr*);
ExprList *sqliteExprListAppend(ExprList*,Expr*,Token*);
void sqliteExprListDelete(ExprList*);
void sqlitePragma(Parse*,Token*,Token*,int);
void sqliteCommitInternalChanges(sqlite*);
void sqliteRollbackInternalChanges(sqlite*);
void sqliteStartTable(Parse*,Token*,Token*);
void sqliteAddColumn(Parse*,Token*);
void sqliteAddDefaultValue(Parse*,Token*,int);
void sqliteEndTable(Parse*,Token*);
void sqliteDropTable(Parse*, Token*);
void sqliteDeleteTable(sqlite*, Table*);
void sqliteInsert(Parse*, Token*, ExprList*, Select*, IdList*);
IdList *sqliteIdListAppend(IdList*, Token*);
void sqliteIdListAddAlias(IdList*, Token*);
void sqliteIdListDelete(IdList*);
void sqliteCreateIndex(Parse*, Token*, Token*, IdList*, Token*, Token*);
void sqliteDropIndex(Parse*, Token*);
int sqliteSelect(Parse*, Select*, int, int);
Select *sqliteSelectNew(ExprList*,IdList*,Expr*,ExprList*,Expr*,ExprList*,int);
void sqliteSelectDelete(Select*);
void sqliteDeleteFrom(Parse*, Token*, Expr*);
void sqliteUpdate(Parse*, Token*, ExprList*, Expr*);
WhereInfo *sqliteWhereBegin(Parse*, IdList*, Expr*, int);
void sqliteWhereEnd(WhereInfo*);
void sqliteExprCode(Parse*, Expr*);
void sqliteExprIfTrue(Parse*, Expr*, int);
void sqliteExprIfFalse(Parse*, Expr*, int);
Table *sqliteFindTable(sqlite*,char*);
void sqliteCopy(Parse*, Token*, Token*, Token*);
void sqliteVacuum(Parse*, Token*);
int sqliteGlobCompare(const unsigned char*,const unsigned char*);
int sqliteLikeCompare(const unsigned char*,const unsigned char*);
char *sqliteTableNameFromToken(Token*);
int sqliteExprCheck(Parse*, Expr*, int, int*);
int sqliteExprCompare(Expr*, Expr*);
int sqliteFuncId(Token*);
int sqliteExprResolveIds(Parse*, IdList*, Expr*);
void sqliteExprResolveInSelect(Parse*, Expr*);
int sqliteExprAnalyzeAggregates(Parse*, Expr*);
void sqliteParseInfoReset(Parse*);
Vdbe *sqliteGetVdbe(Parse*);
int sqliteRandomByte(void);
int sqliteRandomInteger(void);
void sqliteRandomName(char*,char*);
void sqliteBeginTransaction(Parse*);
void sqliteCommitTransaction(Parse*);
void sqliteRollbackTransaction(Parse*);
char *sqlite_mprintf(const char *, ...);
const char *sqliteErrStr(int);
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