be76af171c
This is still using the 2.0 version of pg_bsd_indent. I thought it would be good to commit this separately, so as to document the differences between 2.0 and 2.1 behavior. Discussion: https://postgr.es/m/16296.1558103386@sss.pgh.pa.us
3548 lines
96 KiB
C
3548 lines
96 KiB
C
/*-------------------------------------------------------------------------
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*
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* reorderbuffer.c
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* PostgreSQL logical replay/reorder buffer management
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*
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*
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* Copyright (c) 2012-2019, PostgreSQL Global Development Group
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*
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*
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* IDENTIFICATION
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* src/backend/replication/reorderbuffer.c
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*
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* NOTES
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* This module gets handed individual pieces of transactions in the order
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* they are written to the WAL and is responsible to reassemble them into
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* toplevel transaction sized pieces. When a transaction is completely
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* reassembled - signalled by reading the transaction commit record - it
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* will then call the output plugin (cf. ReorderBufferCommit()) with the
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* individual changes. The output plugins rely on snapshots built by
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* snapbuild.c which hands them to us.
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*
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* Transactions and subtransactions/savepoints in postgres are not
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* immediately linked to each other from outside the performing
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* backend. Only at commit/abort (or special xact_assignment records) they
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* are linked together. Which means that we will have to splice together a
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* toplevel transaction from its subtransactions. To do that efficiently we
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* build a binary heap indexed by the smallest current lsn of the individual
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* subtransactions' changestreams. As the individual streams are inherently
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* ordered by LSN - since that is where we build them from - the transaction
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* can easily be reassembled by always using the subtransaction with the
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* smallest current LSN from the heap.
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*
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* In order to cope with large transactions - which can be several times as
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* big as the available memory - this module supports spooling the contents
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* of a large transactions to disk. When the transaction is replayed the
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* contents of individual (sub-)transactions will be read from disk in
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* chunks.
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*
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* This module also has to deal with reassembling toast records from the
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* individual chunks stored in WAL. When a new (or initial) version of a
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* tuple is stored in WAL it will always be preceded by the toast chunks
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* emitted for the columns stored out of line. Within a single toplevel
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* transaction there will be no other data carrying records between a row's
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* toast chunks and the row data itself. See ReorderBufferToast* for
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* details.
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*
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* ReorderBuffer uses two special memory context types - SlabContext for
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* allocations of fixed-length structures (changes and transactions), and
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* GenerationContext for the variable-length transaction data (allocated
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* and freed in groups with similar lifespan).
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*
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* -------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include <unistd.h>
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#include <sys/stat.h>
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#include "access/heapam.h"
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#include "access/rewriteheap.h"
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#include "access/transam.h"
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#include "access/tuptoaster.h"
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#include "access/xact.h"
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#include "access/xlog_internal.h"
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#include "catalog/catalog.h"
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#include "lib/binaryheap.h"
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#include "miscadmin.h"
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#include "pgstat.h"
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#include "replication/logical.h"
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#include "replication/reorderbuffer.h"
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#include "replication/slot.h"
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#include "replication/snapbuild.h" /* just for SnapBuildSnapDecRefcount */
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#include "storage/bufmgr.h"
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#include "storage/fd.h"
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#include "storage/sinval.h"
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#include "utils/builtins.h"
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#include "utils/combocid.h"
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#include "utils/memdebug.h"
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#include "utils/memutils.h"
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#include "utils/rel.h"
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#include "utils/relfilenodemap.h"
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/* entry for a hash table we use to map from xid to our transaction state */
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typedef struct ReorderBufferTXNByIdEnt
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{
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TransactionId xid;
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ReorderBufferTXN *txn;
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} ReorderBufferTXNByIdEnt;
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/* data structures for (relfilenode, ctid) => (cmin, cmax) mapping */
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typedef struct ReorderBufferTupleCidKey
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{
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RelFileNode relnode;
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ItemPointerData tid;
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} ReorderBufferTupleCidKey;
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typedef struct ReorderBufferTupleCidEnt
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{
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ReorderBufferTupleCidKey key;
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CommandId cmin;
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CommandId cmax;
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CommandId combocid; /* just for debugging */
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} ReorderBufferTupleCidEnt;
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/* k-way in-order change iteration support structures */
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typedef struct ReorderBufferIterTXNEntry
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{
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XLogRecPtr lsn;
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ReorderBufferChange *change;
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ReorderBufferTXN *txn;
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int fd;
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XLogSegNo segno;
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} ReorderBufferIterTXNEntry;
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typedef struct ReorderBufferIterTXNState
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{
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binaryheap *heap;
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Size nr_txns;
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dlist_head old_change;
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ReorderBufferIterTXNEntry entries[FLEXIBLE_ARRAY_MEMBER];
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} ReorderBufferIterTXNState;
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/* toast datastructures */
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typedef struct ReorderBufferToastEnt
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{
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Oid chunk_id; /* toast_table.chunk_id */
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int32 last_chunk_seq; /* toast_table.chunk_seq of the last chunk we
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* have seen */
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Size num_chunks; /* number of chunks we've already seen */
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Size size; /* combined size of chunks seen */
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dlist_head chunks; /* linked list of chunks */
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struct varlena *reconstructed; /* reconstructed varlena now pointed to in
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* main tup */
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} ReorderBufferToastEnt;
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/* Disk serialization support datastructures */
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typedef struct ReorderBufferDiskChange
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{
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Size size;
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ReorderBufferChange change;
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/* data follows */
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} ReorderBufferDiskChange;
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/*
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* Maximum number of changes kept in memory, per transaction. After that,
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* changes are spooled to disk.
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*
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* The current value should be sufficient to decode the entire transaction
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* without hitting disk in OLTP workloads, while starting to spool to disk in
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* other workloads reasonably fast.
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*
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* At some point in the future it probably makes sense to have a more elaborate
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* resource management here, but it's not entirely clear what that would look
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* like.
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*/
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static const Size max_changes_in_memory = 4096;
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/* ---------------------------------------
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* primary reorderbuffer support routines
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* ---------------------------------------
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*/
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static ReorderBufferTXN *ReorderBufferGetTXN(ReorderBuffer *rb);
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static void ReorderBufferReturnTXN(ReorderBuffer *rb, ReorderBufferTXN *txn);
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static ReorderBufferTXN *ReorderBufferTXNByXid(ReorderBuffer *rb,
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TransactionId xid, bool create, bool *is_new,
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XLogRecPtr lsn, bool create_as_top);
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static void ReorderBufferTransferSnapToParent(ReorderBufferTXN *txn,
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ReorderBufferTXN *subtxn);
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static void AssertTXNLsnOrder(ReorderBuffer *rb);
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/* ---------------------------------------
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* support functions for lsn-order iterating over the ->changes of a
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* transaction and its subtransactions
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*
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* used for iteration over the k-way heap merge of a transaction and its
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* subtransactions
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* ---------------------------------------
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*/
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static ReorderBufferIterTXNState *ReorderBufferIterTXNInit(ReorderBuffer *rb, ReorderBufferTXN *txn);
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static ReorderBufferChange *ReorderBufferIterTXNNext(ReorderBuffer *rb, ReorderBufferIterTXNState *state);
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static void ReorderBufferIterTXNFinish(ReorderBuffer *rb,
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ReorderBufferIterTXNState *state);
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static void ReorderBufferExecuteInvalidations(ReorderBuffer *rb, ReorderBufferTXN *txn);
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/*
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* ---------------------------------------
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* Disk serialization support functions
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* ---------------------------------------
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*/
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static void ReorderBufferCheckSerializeTXN(ReorderBuffer *rb, ReorderBufferTXN *txn);
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static void ReorderBufferSerializeTXN(ReorderBuffer *rb, ReorderBufferTXN *txn);
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static void ReorderBufferSerializeChange(ReorderBuffer *rb, ReorderBufferTXN *txn,
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int fd, ReorderBufferChange *change);
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static Size ReorderBufferRestoreChanges(ReorderBuffer *rb, ReorderBufferTXN *txn,
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int *fd, XLogSegNo *segno);
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static void ReorderBufferRestoreChange(ReorderBuffer *rb, ReorderBufferTXN *txn,
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char *change);
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static void ReorderBufferRestoreCleanup(ReorderBuffer *rb, ReorderBufferTXN *txn);
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static void ReorderBufferCleanupSerializedTXNs(const char *slotname);
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static void ReorderBufferSerializedPath(char *path, ReplicationSlot *slot,
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TransactionId xid, XLogSegNo segno);
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static void ReorderBufferFreeSnap(ReorderBuffer *rb, Snapshot snap);
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static Snapshot ReorderBufferCopySnap(ReorderBuffer *rb, Snapshot orig_snap,
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ReorderBufferTXN *txn, CommandId cid);
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/* ---------------------------------------
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* toast reassembly support
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* ---------------------------------------
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*/
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static void ReorderBufferToastInitHash(ReorderBuffer *rb, ReorderBufferTXN *txn);
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static void ReorderBufferToastReset(ReorderBuffer *rb, ReorderBufferTXN *txn);
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static void ReorderBufferToastReplace(ReorderBuffer *rb, ReorderBufferTXN *txn,
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Relation relation, ReorderBufferChange *change);
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static void ReorderBufferToastAppendChunk(ReorderBuffer *rb, ReorderBufferTXN *txn,
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Relation relation, ReorderBufferChange *change);
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/*
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* Allocate a new ReorderBuffer and clean out any old serialized state from
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* prior ReorderBuffer instances for the same slot.
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*/
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ReorderBuffer *
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ReorderBufferAllocate(void)
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{
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ReorderBuffer *buffer;
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HASHCTL hash_ctl;
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MemoryContext new_ctx;
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Assert(MyReplicationSlot != NULL);
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/* allocate memory in own context, to have better accountability */
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new_ctx = AllocSetContextCreate(CurrentMemoryContext,
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"ReorderBuffer",
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ALLOCSET_DEFAULT_SIZES);
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buffer =
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(ReorderBuffer *) MemoryContextAlloc(new_ctx, sizeof(ReorderBuffer));
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memset(&hash_ctl, 0, sizeof(hash_ctl));
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buffer->context = new_ctx;
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buffer->change_context = SlabContextCreate(new_ctx,
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"Change",
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SLAB_DEFAULT_BLOCK_SIZE,
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sizeof(ReorderBufferChange));
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buffer->txn_context = SlabContextCreate(new_ctx,
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"TXN",
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SLAB_DEFAULT_BLOCK_SIZE,
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sizeof(ReorderBufferTXN));
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buffer->tup_context = GenerationContextCreate(new_ctx,
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"Tuples",
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SLAB_LARGE_BLOCK_SIZE);
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hash_ctl.keysize = sizeof(TransactionId);
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hash_ctl.entrysize = sizeof(ReorderBufferTXNByIdEnt);
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hash_ctl.hcxt = buffer->context;
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buffer->by_txn = hash_create("ReorderBufferByXid", 1000, &hash_ctl,
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HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
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buffer->by_txn_last_xid = InvalidTransactionId;
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buffer->by_txn_last_txn = NULL;
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buffer->outbuf = NULL;
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buffer->outbufsize = 0;
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buffer->current_restart_decoding_lsn = InvalidXLogRecPtr;
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dlist_init(&buffer->toplevel_by_lsn);
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dlist_init(&buffer->txns_by_base_snapshot_lsn);
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/*
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* Ensure there's no stale data from prior uses of this slot, in case some
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* prior exit avoided calling ReorderBufferFree. Failure to do this can
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* produce duplicated txns, and it's very cheap if there's nothing there.
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*/
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ReorderBufferCleanupSerializedTXNs(NameStr(MyReplicationSlot->data.name));
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return buffer;
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}
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/*
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* Free a ReorderBuffer
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*/
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void
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ReorderBufferFree(ReorderBuffer *rb)
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{
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MemoryContext context = rb->context;
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/*
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* We free separately allocated data by entirely scrapping reorderbuffer's
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* memory context.
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*/
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MemoryContextDelete(context);
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/* Free disk space used by unconsumed reorder buffers */
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ReorderBufferCleanupSerializedTXNs(NameStr(MyReplicationSlot->data.name));
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}
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/*
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* Get an unused, possibly preallocated, ReorderBufferTXN.
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*/
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static ReorderBufferTXN *
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ReorderBufferGetTXN(ReorderBuffer *rb)
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{
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ReorderBufferTXN *txn;
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txn = (ReorderBufferTXN *)
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MemoryContextAlloc(rb->txn_context, sizeof(ReorderBufferTXN));
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memset(txn, 0, sizeof(ReorderBufferTXN));
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dlist_init(&txn->changes);
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dlist_init(&txn->tuplecids);
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dlist_init(&txn->subtxns);
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return txn;
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}
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/*
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* Free a ReorderBufferTXN.
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*/
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static void
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ReorderBufferReturnTXN(ReorderBuffer *rb, ReorderBufferTXN *txn)
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{
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/* clean the lookup cache if we were cached (quite likely) */
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if (rb->by_txn_last_xid == txn->xid)
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{
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rb->by_txn_last_xid = InvalidTransactionId;
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rb->by_txn_last_txn = NULL;
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}
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/* free data that's contained */
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if (txn->tuplecid_hash != NULL)
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{
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hash_destroy(txn->tuplecid_hash);
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txn->tuplecid_hash = NULL;
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}
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if (txn->invalidations)
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{
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pfree(txn->invalidations);
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txn->invalidations = NULL;
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}
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pfree(txn);
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}
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/*
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* Get an fresh ReorderBufferChange.
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*/
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ReorderBufferChange *
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ReorderBufferGetChange(ReorderBuffer *rb)
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{
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ReorderBufferChange *change;
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change = (ReorderBufferChange *)
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MemoryContextAlloc(rb->change_context, sizeof(ReorderBufferChange));
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memset(change, 0, sizeof(ReorderBufferChange));
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return change;
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}
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/*
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* Free an ReorderBufferChange.
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*/
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void
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ReorderBufferReturnChange(ReorderBuffer *rb, ReorderBufferChange *change)
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{
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/* free contained data */
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switch (change->action)
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{
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case REORDER_BUFFER_CHANGE_INSERT:
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case REORDER_BUFFER_CHANGE_UPDATE:
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case REORDER_BUFFER_CHANGE_DELETE:
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case REORDER_BUFFER_CHANGE_INTERNAL_SPEC_INSERT:
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if (change->data.tp.newtuple)
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{
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ReorderBufferReturnTupleBuf(rb, change->data.tp.newtuple);
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change->data.tp.newtuple = NULL;
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}
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if (change->data.tp.oldtuple)
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{
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ReorderBufferReturnTupleBuf(rb, change->data.tp.oldtuple);
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change->data.tp.oldtuple = NULL;
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}
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break;
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case REORDER_BUFFER_CHANGE_MESSAGE:
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if (change->data.msg.prefix != NULL)
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pfree(change->data.msg.prefix);
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change->data.msg.prefix = NULL;
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if (change->data.msg.message != NULL)
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pfree(change->data.msg.message);
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change->data.msg.message = NULL;
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break;
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case REORDER_BUFFER_CHANGE_INTERNAL_SNAPSHOT:
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if (change->data.snapshot)
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{
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ReorderBufferFreeSnap(rb, change->data.snapshot);
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change->data.snapshot = NULL;
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}
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break;
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/* no data in addition to the struct itself */
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case REORDER_BUFFER_CHANGE_TRUNCATE:
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if (change->data.truncate.relids != NULL)
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{
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ReorderBufferReturnRelids(rb, change->data.truncate.relids);
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change->data.truncate.relids = NULL;
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}
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break;
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case REORDER_BUFFER_CHANGE_INTERNAL_SPEC_CONFIRM:
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case REORDER_BUFFER_CHANGE_INTERNAL_COMMAND_ID:
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case REORDER_BUFFER_CHANGE_INTERNAL_TUPLECID:
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break;
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}
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pfree(change);
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}
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/*
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* Get a fresh ReorderBufferTupleBuf fitting at least a tuple of size
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* tuple_len (excluding header overhead).
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*/
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ReorderBufferTupleBuf *
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ReorderBufferGetTupleBuf(ReorderBuffer *rb, Size tuple_len)
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{
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ReorderBufferTupleBuf *tuple;
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Size alloc_len;
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alloc_len = tuple_len + SizeofHeapTupleHeader;
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tuple = (ReorderBufferTupleBuf *)
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MemoryContextAlloc(rb->tup_context,
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sizeof(ReorderBufferTupleBuf) +
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MAXIMUM_ALIGNOF + alloc_len);
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tuple->alloc_tuple_size = alloc_len;
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tuple->tuple.t_data = ReorderBufferTupleBufData(tuple);
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return tuple;
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}
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/*
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* Free an ReorderBufferTupleBuf.
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*/
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void
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ReorderBufferReturnTupleBuf(ReorderBuffer *rb, ReorderBufferTupleBuf *tuple)
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{
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pfree(tuple);
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}
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/*
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* Get an array for relids of truncated relations.
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*
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* We use the global memory context (for the whole reorder buffer), because
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* none of the existing ones seems like a good match (some are SLAB, so we
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* can't use those, and tup_context is meant for tuple data, not relids). We
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* could add yet another context, but it seems like an overkill - TRUNCATE is
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* not particularly common operation, so it does not seem worth it.
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*/
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Oid *
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ReorderBufferGetRelids(ReorderBuffer *rb, int nrelids)
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{
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Oid *relids;
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Size alloc_len;
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alloc_len = sizeof(Oid) * nrelids;
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relids = (Oid *) MemoryContextAlloc(rb->context, alloc_len);
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return relids;
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}
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/*
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* Free an array of relids.
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*/
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void
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ReorderBufferReturnRelids(ReorderBuffer *rb, Oid *relids)
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{
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pfree(relids);
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}
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/*
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* Return the ReorderBufferTXN from the given buffer, specified by Xid.
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* If create is true, and a transaction doesn't already exist, create it
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* (with the given LSN, and as top transaction if that's specified);
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* when this happens, is_new is set to true.
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*/
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static ReorderBufferTXN *
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ReorderBufferTXNByXid(ReorderBuffer *rb, TransactionId xid, bool create,
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bool *is_new, XLogRecPtr lsn, bool create_as_top)
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{
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ReorderBufferTXN *txn;
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ReorderBufferTXNByIdEnt *ent;
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bool found;
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Assert(TransactionIdIsValid(xid));
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/*
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* Check the one-entry lookup cache first
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*/
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if (TransactionIdIsValid(rb->by_txn_last_xid) &&
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|
rb->by_txn_last_xid == xid)
|
|
{
|
|
txn = rb->by_txn_last_txn;
|
|
|
|
if (txn != NULL)
|
|
{
|
|
/* found it, and it's valid */
|
|
if (is_new)
|
|
*is_new = false;
|
|
return txn;
|
|
}
|
|
|
|
/*
|
|
* cached as non-existent, and asked not to create? Then nothing else
|
|
* to do.
|
|
*/
|
|
if (!create)
|
|
return NULL;
|
|
/* otherwise fall through to create it */
|
|
}
|
|
|
|
/*
|
|
* If the cache wasn't hit or it yielded an "does-not-exist" and we want
|
|
* to create an entry.
|
|
*/
|
|
|
|
/* search the lookup table */
|
|
ent = (ReorderBufferTXNByIdEnt *)
|
|
hash_search(rb->by_txn,
|
|
(void *) &xid,
|
|
create ? HASH_ENTER : HASH_FIND,
|
|
&found);
|
|
if (found)
|
|
txn = ent->txn;
|
|
else if (create)
|
|
{
|
|
/* initialize the new entry, if creation was requested */
|
|
Assert(ent != NULL);
|
|
Assert(lsn != InvalidXLogRecPtr);
|
|
|
|
ent->txn = ReorderBufferGetTXN(rb);
|
|
ent->txn->xid = xid;
|
|
txn = ent->txn;
|
|
txn->first_lsn = lsn;
|
|
txn->restart_decoding_lsn = rb->current_restart_decoding_lsn;
|
|
|
|
if (create_as_top)
|
|
{
|
|
dlist_push_tail(&rb->toplevel_by_lsn, &txn->node);
|
|
AssertTXNLsnOrder(rb);
|
|
}
|
|
}
|
|
else
|
|
txn = NULL; /* not found and not asked to create */
|
|
|
|
/* update cache */
|
|
rb->by_txn_last_xid = xid;
|
|
rb->by_txn_last_txn = txn;
|
|
|
|
if (is_new)
|
|
*is_new = !found;
|
|
|
|
Assert(!create || txn != NULL);
|
|
return txn;
|
|
}
|
|
|
|
/*
|
|
* Queue a change into a transaction so it can be replayed upon commit.
|
|
*/
|
|
void
|
|
ReorderBufferQueueChange(ReorderBuffer *rb, TransactionId xid, XLogRecPtr lsn,
|
|
ReorderBufferChange *change)
|
|
{
|
|
ReorderBufferTXN *txn;
|
|
|
|
txn = ReorderBufferTXNByXid(rb, xid, true, NULL, lsn, true);
|
|
|
|
change->lsn = lsn;
|
|
Assert(InvalidXLogRecPtr != lsn);
|
|
dlist_push_tail(&txn->changes, &change->node);
|
|
txn->nentries++;
|
|
txn->nentries_mem++;
|
|
|
|
ReorderBufferCheckSerializeTXN(rb, txn);
|
|
}
|
|
|
|
/*
|
|
* Queue message into a transaction so it can be processed upon commit.
|
|
*/
|
|
void
|
|
ReorderBufferQueueMessage(ReorderBuffer *rb, TransactionId xid,
|
|
Snapshot snapshot, XLogRecPtr lsn,
|
|
bool transactional, const char *prefix,
|
|
Size message_size, const char *message)
|
|
{
|
|
if (transactional)
|
|
{
|
|
MemoryContext oldcontext;
|
|
ReorderBufferChange *change;
|
|
|
|
Assert(xid != InvalidTransactionId);
|
|
|
|
oldcontext = MemoryContextSwitchTo(rb->context);
|
|
|
|
change = ReorderBufferGetChange(rb);
|
|
change->action = REORDER_BUFFER_CHANGE_MESSAGE;
|
|
change->data.msg.prefix = pstrdup(prefix);
|
|
change->data.msg.message_size = message_size;
|
|
change->data.msg.message = palloc(message_size);
|
|
memcpy(change->data.msg.message, message, message_size);
|
|
|
|
ReorderBufferQueueChange(rb, xid, lsn, change);
|
|
|
|
MemoryContextSwitchTo(oldcontext);
|
|
}
|
|
else
|
|
{
|
|
ReorderBufferTXN *txn = NULL;
|
|
volatile Snapshot snapshot_now = snapshot;
|
|
|
|
if (xid != InvalidTransactionId)
|
|
txn = ReorderBufferTXNByXid(rb, xid, true, NULL, lsn, true);
|
|
|
|
/* setup snapshot to allow catalog access */
|
|
SetupHistoricSnapshot(snapshot_now, NULL);
|
|
PG_TRY();
|
|
{
|
|
rb->message(rb, txn, lsn, false, prefix, message_size, message);
|
|
|
|
TeardownHistoricSnapshot(false);
|
|
}
|
|
PG_CATCH();
|
|
{
|
|
TeardownHistoricSnapshot(true);
|
|
PG_RE_THROW();
|
|
}
|
|
PG_END_TRY();
|
|
}
|
|
}
|
|
|
|
/*
|
|
* AssertTXNLsnOrder
|
|
* Verify LSN ordering of transaction lists in the reorderbuffer
|
|
*
|
|
* Other LSN-related invariants are checked too.
|
|
*
|
|
* No-op if assertions are not in use.
|
|
*/
|
|
static void
|
|
AssertTXNLsnOrder(ReorderBuffer *rb)
|
|
{
|
|
#ifdef USE_ASSERT_CHECKING
|
|
dlist_iter iter;
|
|
XLogRecPtr prev_first_lsn = InvalidXLogRecPtr;
|
|
XLogRecPtr prev_base_snap_lsn = InvalidXLogRecPtr;
|
|
|
|
dlist_foreach(iter, &rb->toplevel_by_lsn)
|
|
{
|
|
ReorderBufferTXN *cur_txn = dlist_container(ReorderBufferTXN, node,
|
|
iter.cur);
|
|
|
|
/* start LSN must be set */
|
|
Assert(cur_txn->first_lsn != InvalidXLogRecPtr);
|
|
|
|
/* If there is an end LSN, it must be higher than start LSN */
|
|
if (cur_txn->end_lsn != InvalidXLogRecPtr)
|
|
Assert(cur_txn->first_lsn <= cur_txn->end_lsn);
|
|
|
|
/* Current initial LSN must be strictly higher than previous */
|
|
if (prev_first_lsn != InvalidXLogRecPtr)
|
|
Assert(prev_first_lsn < cur_txn->first_lsn);
|
|
|
|
/* known-as-subtxn txns must not be listed */
|
|
Assert(!cur_txn->is_known_as_subxact);
|
|
|
|
prev_first_lsn = cur_txn->first_lsn;
|
|
}
|
|
|
|
dlist_foreach(iter, &rb->txns_by_base_snapshot_lsn)
|
|
{
|
|
ReorderBufferTXN *cur_txn = dlist_container(ReorderBufferTXN,
|
|
base_snapshot_node,
|
|
iter.cur);
|
|
|
|
/* base snapshot (and its LSN) must be set */
|
|
Assert(cur_txn->base_snapshot != NULL);
|
|
Assert(cur_txn->base_snapshot_lsn != InvalidXLogRecPtr);
|
|
|
|
/* current LSN must be strictly higher than previous */
|
|
if (prev_base_snap_lsn != InvalidXLogRecPtr)
|
|
Assert(prev_base_snap_lsn < cur_txn->base_snapshot_lsn);
|
|
|
|
/* known-as-subtxn txns must not be listed */
|
|
Assert(!cur_txn->is_known_as_subxact);
|
|
|
|
prev_base_snap_lsn = cur_txn->base_snapshot_lsn;
|
|
}
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* ReorderBufferGetOldestTXN
|
|
* Return oldest transaction in reorderbuffer
|
|
*/
|
|
ReorderBufferTXN *
|
|
ReorderBufferGetOldestTXN(ReorderBuffer *rb)
|
|
{
|
|
ReorderBufferTXN *txn;
|
|
|
|
AssertTXNLsnOrder(rb);
|
|
|
|
if (dlist_is_empty(&rb->toplevel_by_lsn))
|
|
return NULL;
|
|
|
|
txn = dlist_head_element(ReorderBufferTXN, node, &rb->toplevel_by_lsn);
|
|
|
|
Assert(!txn->is_known_as_subxact);
|
|
Assert(txn->first_lsn != InvalidXLogRecPtr);
|
|
return txn;
|
|
}
|
|
|
|
/*
|
|
* ReorderBufferGetOldestXmin
|
|
* Return oldest Xmin in reorderbuffer
|
|
*
|
|
* Returns oldest possibly running Xid from the point of view of snapshots
|
|
* used in the transactions kept by reorderbuffer, or InvalidTransactionId if
|
|
* there are none.
|
|
*
|
|
* Since snapshots are assigned monotonically, this equals the Xmin of the
|
|
* base snapshot with minimal base_snapshot_lsn.
|
|
*/
|
|
TransactionId
|
|
ReorderBufferGetOldestXmin(ReorderBuffer *rb)
|
|
{
|
|
ReorderBufferTXN *txn;
|
|
|
|
AssertTXNLsnOrder(rb);
|
|
|
|
if (dlist_is_empty(&rb->txns_by_base_snapshot_lsn))
|
|
return InvalidTransactionId;
|
|
|
|
txn = dlist_head_element(ReorderBufferTXN, base_snapshot_node,
|
|
&rb->txns_by_base_snapshot_lsn);
|
|
return txn->base_snapshot->xmin;
|
|
}
|
|
|
|
void
|
|
ReorderBufferSetRestartPoint(ReorderBuffer *rb, XLogRecPtr ptr)
|
|
{
|
|
rb->current_restart_decoding_lsn = ptr;
|
|
}
|
|
|
|
/*
|
|
* ReorderBufferAssignChild
|
|
*
|
|
* Make note that we know that subxid is a subtransaction of xid, seen as of
|
|
* the given lsn.
|
|
*/
|
|
void
|
|
ReorderBufferAssignChild(ReorderBuffer *rb, TransactionId xid,
|
|
TransactionId subxid, XLogRecPtr lsn)
|
|
{
|
|
ReorderBufferTXN *txn;
|
|
ReorderBufferTXN *subtxn;
|
|
bool new_top;
|
|
bool new_sub;
|
|
|
|
txn = ReorderBufferTXNByXid(rb, xid, true, &new_top, lsn, true);
|
|
subtxn = ReorderBufferTXNByXid(rb, subxid, true, &new_sub, lsn, false);
|
|
|
|
if (new_top && !new_sub)
|
|
elog(ERROR, "subtransaction logged without previous top-level txn record");
|
|
|
|
if (!new_sub)
|
|
{
|
|
if (subtxn->is_known_as_subxact)
|
|
{
|
|
/* already associated, nothing to do */
|
|
return;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* We already saw this transaction, but initially added it to the
|
|
* list of top-level txns. Now that we know it's not top-level,
|
|
* remove it from there.
|
|
*/
|
|
dlist_delete(&subtxn->node);
|
|
}
|
|
}
|
|
|
|
subtxn->is_known_as_subxact = true;
|
|
subtxn->toplevel_xid = xid;
|
|
Assert(subtxn->nsubtxns == 0);
|
|
|
|
/* add to subtransaction list */
|
|
dlist_push_tail(&txn->subtxns, &subtxn->node);
|
|
txn->nsubtxns++;
|
|
|
|
/* Possibly transfer the subtxn's snapshot to its top-level txn. */
|
|
ReorderBufferTransferSnapToParent(txn, subtxn);
|
|
|
|
/* Verify LSN-ordering invariant */
|
|
AssertTXNLsnOrder(rb);
|
|
}
|
|
|
|
/*
|
|
* ReorderBufferTransferSnapToParent
|
|
* Transfer base snapshot from subtxn to top-level txn, if needed
|
|
*
|
|
* This is done if the top-level txn doesn't have a base snapshot, or if the
|
|
* subtxn's base snapshot has an earlier LSN than the top-level txn's base
|
|
* snapshot's LSN. This can happen if there are no changes in the toplevel
|
|
* txn but there are some in the subtxn, or the first change in subtxn has
|
|
* earlier LSN than first change in the top-level txn and we learned about
|
|
* their kinship only now.
|
|
*
|
|
* The subtransaction's snapshot is cleared regardless of the transfer
|
|
* happening, since it's not needed anymore in either case.
|
|
*
|
|
* We do this as soon as we become aware of their kinship, to avoid queueing
|
|
* extra snapshots to txns known-as-subtxns -- only top-level txns will
|
|
* receive further snapshots.
|
|
*/
|
|
static void
|
|
ReorderBufferTransferSnapToParent(ReorderBufferTXN *txn,
|
|
ReorderBufferTXN *subtxn)
|
|
{
|
|
Assert(subtxn->toplevel_xid == txn->xid);
|
|
|
|
if (subtxn->base_snapshot != NULL)
|
|
{
|
|
if (txn->base_snapshot == NULL ||
|
|
subtxn->base_snapshot_lsn < txn->base_snapshot_lsn)
|
|
{
|
|
/*
|
|
* If the toplevel transaction already has a base snapshot but
|
|
* it's newer than the subxact's, purge it.
|
|
*/
|
|
if (txn->base_snapshot != NULL)
|
|
{
|
|
SnapBuildSnapDecRefcount(txn->base_snapshot);
|
|
dlist_delete(&txn->base_snapshot_node);
|
|
}
|
|
|
|
/*
|
|
* The snapshot is now the top transaction's; transfer it, and
|
|
* adjust the list position of the top transaction in the list by
|
|
* moving it to where the subtransaction is.
|
|
*/
|
|
txn->base_snapshot = subtxn->base_snapshot;
|
|
txn->base_snapshot_lsn = subtxn->base_snapshot_lsn;
|
|
dlist_insert_before(&subtxn->base_snapshot_node,
|
|
&txn->base_snapshot_node);
|
|
|
|
/*
|
|
* The subtransaction doesn't have a snapshot anymore (so it
|
|
* mustn't be in the list.)
|
|
*/
|
|
subtxn->base_snapshot = NULL;
|
|
subtxn->base_snapshot_lsn = InvalidXLogRecPtr;
|
|
dlist_delete(&subtxn->base_snapshot_node);
|
|
}
|
|
else
|
|
{
|
|
/* Base snap of toplevel is fine, so subxact's is not needed */
|
|
SnapBuildSnapDecRefcount(subtxn->base_snapshot);
|
|
dlist_delete(&subtxn->base_snapshot_node);
|
|
subtxn->base_snapshot = NULL;
|
|
subtxn->base_snapshot_lsn = InvalidXLogRecPtr;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Associate a subtransaction with its toplevel transaction at commit
|
|
* time. There may be no further changes added after this.
|
|
*/
|
|
void
|
|
ReorderBufferCommitChild(ReorderBuffer *rb, TransactionId xid,
|
|
TransactionId subxid, XLogRecPtr commit_lsn,
|
|
XLogRecPtr end_lsn)
|
|
{
|
|
ReorderBufferTXN *subtxn;
|
|
|
|
subtxn = ReorderBufferTXNByXid(rb, subxid, false, NULL,
|
|
InvalidXLogRecPtr, false);
|
|
|
|
/*
|
|
* No need to do anything if that subtxn didn't contain any changes
|
|
*/
|
|
if (!subtxn)
|
|
return;
|
|
|
|
subtxn->final_lsn = commit_lsn;
|
|
subtxn->end_lsn = end_lsn;
|
|
|
|
/*
|
|
* Assign this subxact as a child of the toplevel xact (no-op if already
|
|
* done.)
|
|
*/
|
|
ReorderBufferAssignChild(rb, xid, subxid, InvalidXLogRecPtr);
|
|
}
|
|
|
|
|
|
/*
|
|
* Support for efficiently iterating over a transaction's and its
|
|
* subtransactions' changes.
|
|
*
|
|
* We do by doing a k-way merge between transactions/subtransactions. For that
|
|
* we model the current heads of the different transactions as a binary heap
|
|
* so we easily know which (sub-)transaction has the change with the smallest
|
|
* lsn next.
|
|
*
|
|
* We assume the changes in individual transactions are already sorted by LSN.
|
|
*/
|
|
|
|
/*
|
|
* Binary heap comparison function.
|
|
*/
|
|
static int
|
|
ReorderBufferIterCompare(Datum a, Datum b, void *arg)
|
|
{
|
|
ReorderBufferIterTXNState *state = (ReorderBufferIterTXNState *) arg;
|
|
XLogRecPtr pos_a = state->entries[DatumGetInt32(a)].lsn;
|
|
XLogRecPtr pos_b = state->entries[DatumGetInt32(b)].lsn;
|
|
|
|
if (pos_a < pos_b)
|
|
return 1;
|
|
else if (pos_a == pos_b)
|
|
return 0;
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* Allocate & initialize an iterator which iterates in lsn order over a
|
|
* transaction and all its subtransactions.
|
|
*/
|
|
static ReorderBufferIterTXNState *
|
|
ReorderBufferIterTXNInit(ReorderBuffer *rb, ReorderBufferTXN *txn)
|
|
{
|
|
Size nr_txns = 0;
|
|
ReorderBufferIterTXNState *state;
|
|
dlist_iter cur_txn_i;
|
|
int32 off;
|
|
|
|
/*
|
|
* Calculate the size of our heap: one element for every transaction that
|
|
* contains changes. (Besides the transactions already in the reorder
|
|
* buffer, we count the one we were directly passed.)
|
|
*/
|
|
if (txn->nentries > 0)
|
|
nr_txns++;
|
|
|
|
dlist_foreach(cur_txn_i, &txn->subtxns)
|
|
{
|
|
ReorderBufferTXN *cur_txn;
|
|
|
|
cur_txn = dlist_container(ReorderBufferTXN, node, cur_txn_i.cur);
|
|
|
|
if (cur_txn->nentries > 0)
|
|
nr_txns++;
|
|
}
|
|
|
|
/*
|
|
* TODO: Consider adding fastpath for the rather common nr_txns=1 case, no
|
|
* need to allocate/build a heap then.
|
|
*/
|
|
|
|
/* allocate iteration state */
|
|
state = (ReorderBufferIterTXNState *)
|
|
MemoryContextAllocZero(rb->context,
|
|
sizeof(ReorderBufferIterTXNState) +
|
|
sizeof(ReorderBufferIterTXNEntry) * nr_txns);
|
|
|
|
state->nr_txns = nr_txns;
|
|
dlist_init(&state->old_change);
|
|
|
|
for (off = 0; off < state->nr_txns; off++)
|
|
{
|
|
state->entries[off].fd = -1;
|
|
state->entries[off].segno = 0;
|
|
}
|
|
|
|
/* allocate heap */
|
|
state->heap = binaryheap_allocate(state->nr_txns,
|
|
ReorderBufferIterCompare,
|
|
state);
|
|
|
|
/*
|
|
* Now insert items into the binary heap, in an unordered fashion. (We
|
|
* will run a heap assembly step at the end; this is more efficient.)
|
|
*/
|
|
|
|
off = 0;
|
|
|
|
/* add toplevel transaction if it contains changes */
|
|
if (txn->nentries > 0)
|
|
{
|
|
ReorderBufferChange *cur_change;
|
|
|
|
if (txn->serialized)
|
|
{
|
|
/* serialize remaining changes */
|
|
ReorderBufferSerializeTXN(rb, txn);
|
|
ReorderBufferRestoreChanges(rb, txn, &state->entries[off].fd,
|
|
&state->entries[off].segno);
|
|
}
|
|
|
|
cur_change = dlist_head_element(ReorderBufferChange, node,
|
|
&txn->changes);
|
|
|
|
state->entries[off].lsn = cur_change->lsn;
|
|
state->entries[off].change = cur_change;
|
|
state->entries[off].txn = txn;
|
|
|
|
binaryheap_add_unordered(state->heap, Int32GetDatum(off++));
|
|
}
|
|
|
|
/* add subtransactions if they contain changes */
|
|
dlist_foreach(cur_txn_i, &txn->subtxns)
|
|
{
|
|
ReorderBufferTXN *cur_txn;
|
|
|
|
cur_txn = dlist_container(ReorderBufferTXN, node, cur_txn_i.cur);
|
|
|
|
if (cur_txn->nentries > 0)
|
|
{
|
|
ReorderBufferChange *cur_change;
|
|
|
|
if (cur_txn->serialized)
|
|
{
|
|
/* serialize remaining changes */
|
|
ReorderBufferSerializeTXN(rb, cur_txn);
|
|
ReorderBufferRestoreChanges(rb, cur_txn,
|
|
&state->entries[off].fd,
|
|
&state->entries[off].segno);
|
|
}
|
|
cur_change = dlist_head_element(ReorderBufferChange, node,
|
|
&cur_txn->changes);
|
|
|
|
state->entries[off].lsn = cur_change->lsn;
|
|
state->entries[off].change = cur_change;
|
|
state->entries[off].txn = cur_txn;
|
|
|
|
binaryheap_add_unordered(state->heap, Int32GetDatum(off++));
|
|
}
|
|
}
|
|
|
|
/* assemble a valid binary heap */
|
|
binaryheap_build(state->heap);
|
|
|
|
return state;
|
|
}
|
|
|
|
/*
|
|
* Return the next change when iterating over a transaction and its
|
|
* subtransactions.
|
|
*
|
|
* Returns NULL when no further changes exist.
|
|
*/
|
|
static ReorderBufferChange *
|
|
ReorderBufferIterTXNNext(ReorderBuffer *rb, ReorderBufferIterTXNState *state)
|
|
{
|
|
ReorderBufferChange *change;
|
|
ReorderBufferIterTXNEntry *entry;
|
|
int32 off;
|
|
|
|
/* nothing there anymore */
|
|
if (state->heap->bh_size == 0)
|
|
return NULL;
|
|
|
|
off = DatumGetInt32(binaryheap_first(state->heap));
|
|
entry = &state->entries[off];
|
|
|
|
/* free memory we might have "leaked" in the previous *Next call */
|
|
if (!dlist_is_empty(&state->old_change))
|
|
{
|
|
change = dlist_container(ReorderBufferChange, node,
|
|
dlist_pop_head_node(&state->old_change));
|
|
ReorderBufferReturnChange(rb, change);
|
|
Assert(dlist_is_empty(&state->old_change));
|
|
}
|
|
|
|
change = entry->change;
|
|
|
|
/*
|
|
* update heap with information about which transaction has the next
|
|
* relevant change in LSN order
|
|
*/
|
|
|
|
/* there are in-memory changes */
|
|
if (dlist_has_next(&entry->txn->changes, &entry->change->node))
|
|
{
|
|
dlist_node *next = dlist_next_node(&entry->txn->changes, &change->node);
|
|
ReorderBufferChange *next_change =
|
|
dlist_container(ReorderBufferChange, node, next);
|
|
|
|
/* txn stays the same */
|
|
state->entries[off].lsn = next_change->lsn;
|
|
state->entries[off].change = next_change;
|
|
|
|
binaryheap_replace_first(state->heap, Int32GetDatum(off));
|
|
return change;
|
|
}
|
|
|
|
/* try to load changes from disk */
|
|
if (entry->txn->nentries != entry->txn->nentries_mem)
|
|
{
|
|
/*
|
|
* Ugly: restoring changes will reuse *Change records, thus delete the
|
|
* current one from the per-tx list and only free in the next call.
|
|
*/
|
|
dlist_delete(&change->node);
|
|
dlist_push_tail(&state->old_change, &change->node);
|
|
|
|
if (ReorderBufferRestoreChanges(rb, entry->txn, &entry->fd,
|
|
&state->entries[off].segno))
|
|
{
|
|
/* successfully restored changes from disk */
|
|
ReorderBufferChange *next_change =
|
|
dlist_head_element(ReorderBufferChange, node,
|
|
&entry->txn->changes);
|
|
|
|
elog(DEBUG2, "restored %u/%u changes from disk",
|
|
(uint32) entry->txn->nentries_mem,
|
|
(uint32) entry->txn->nentries);
|
|
|
|
Assert(entry->txn->nentries_mem);
|
|
/* txn stays the same */
|
|
state->entries[off].lsn = next_change->lsn;
|
|
state->entries[off].change = next_change;
|
|
binaryheap_replace_first(state->heap, Int32GetDatum(off));
|
|
|
|
return change;
|
|
}
|
|
}
|
|
|
|
/* ok, no changes there anymore, remove */
|
|
binaryheap_remove_first(state->heap);
|
|
|
|
return change;
|
|
}
|
|
|
|
/*
|
|
* Deallocate the iterator
|
|
*/
|
|
static void
|
|
ReorderBufferIterTXNFinish(ReorderBuffer *rb,
|
|
ReorderBufferIterTXNState *state)
|
|
{
|
|
int32 off;
|
|
|
|
for (off = 0; off < state->nr_txns; off++)
|
|
{
|
|
if (state->entries[off].fd != -1)
|
|
CloseTransientFile(state->entries[off].fd);
|
|
}
|
|
|
|
/* free memory we might have "leaked" in the last *Next call */
|
|
if (!dlist_is_empty(&state->old_change))
|
|
{
|
|
ReorderBufferChange *change;
|
|
|
|
change = dlist_container(ReorderBufferChange, node,
|
|
dlist_pop_head_node(&state->old_change));
|
|
ReorderBufferReturnChange(rb, change);
|
|
Assert(dlist_is_empty(&state->old_change));
|
|
}
|
|
|
|
binaryheap_free(state->heap);
|
|
pfree(state);
|
|
}
|
|
|
|
/*
|
|
* Cleanup the contents of a transaction, usually after the transaction
|
|
* committed or aborted.
|
|
*/
|
|
static void
|
|
ReorderBufferCleanupTXN(ReorderBuffer *rb, ReorderBufferTXN *txn)
|
|
{
|
|
bool found;
|
|
dlist_mutable_iter iter;
|
|
|
|
/* cleanup subtransactions & their changes */
|
|
dlist_foreach_modify(iter, &txn->subtxns)
|
|
{
|
|
ReorderBufferTXN *subtxn;
|
|
|
|
subtxn = dlist_container(ReorderBufferTXN, node, iter.cur);
|
|
|
|
/*
|
|
* Subtransactions are always associated to the toplevel TXN, even if
|
|
* they originally were happening inside another subtxn, so we won't
|
|
* ever recurse more than one level deep here.
|
|
*/
|
|
Assert(subtxn->is_known_as_subxact);
|
|
Assert(subtxn->nsubtxns == 0);
|
|
|
|
ReorderBufferCleanupTXN(rb, subtxn);
|
|
}
|
|
|
|
/* cleanup changes in the toplevel txn */
|
|
dlist_foreach_modify(iter, &txn->changes)
|
|
{
|
|
ReorderBufferChange *change;
|
|
|
|
change = dlist_container(ReorderBufferChange, node, iter.cur);
|
|
|
|
ReorderBufferReturnChange(rb, change);
|
|
}
|
|
|
|
/*
|
|
* Cleanup the tuplecids we stored for decoding catalog snapshot access.
|
|
* They are always stored in the toplevel transaction.
|
|
*/
|
|
dlist_foreach_modify(iter, &txn->tuplecids)
|
|
{
|
|
ReorderBufferChange *change;
|
|
|
|
change = dlist_container(ReorderBufferChange, node, iter.cur);
|
|
Assert(change->action == REORDER_BUFFER_CHANGE_INTERNAL_TUPLECID);
|
|
ReorderBufferReturnChange(rb, change);
|
|
}
|
|
|
|
/*
|
|
* Cleanup the base snapshot, if set.
|
|
*/
|
|
if (txn->base_snapshot != NULL)
|
|
{
|
|
SnapBuildSnapDecRefcount(txn->base_snapshot);
|
|
dlist_delete(&txn->base_snapshot_node);
|
|
}
|
|
|
|
/*
|
|
* Remove TXN from its containing list.
|
|
*
|
|
* Note: if txn->is_known_as_subxact, we are deleting the TXN from its
|
|
* parent's list of known subxacts; this leaves the parent's nsubxacts
|
|
* count too high, but we don't care. Otherwise, we are deleting the TXN
|
|
* from the LSN-ordered list of toplevel TXNs.
|
|
*/
|
|
dlist_delete(&txn->node);
|
|
|
|
/* now remove reference from buffer */
|
|
hash_search(rb->by_txn,
|
|
(void *) &txn->xid,
|
|
HASH_REMOVE,
|
|
&found);
|
|
Assert(found);
|
|
|
|
/* remove entries spilled to disk */
|
|
if (txn->serialized)
|
|
ReorderBufferRestoreCleanup(rb, txn);
|
|
|
|
/* deallocate */
|
|
ReorderBufferReturnTXN(rb, txn);
|
|
}
|
|
|
|
/*
|
|
* Build a hash with a (relfilenode, ctid) -> (cmin, cmax) mapping for use by
|
|
* HeapTupleSatisfiesHistoricMVCC.
|
|
*/
|
|
static void
|
|
ReorderBufferBuildTupleCidHash(ReorderBuffer *rb, ReorderBufferTXN *txn)
|
|
{
|
|
dlist_iter iter;
|
|
HASHCTL hash_ctl;
|
|
|
|
if (!txn->has_catalog_changes || dlist_is_empty(&txn->tuplecids))
|
|
return;
|
|
|
|
memset(&hash_ctl, 0, sizeof(hash_ctl));
|
|
|
|
hash_ctl.keysize = sizeof(ReorderBufferTupleCidKey);
|
|
hash_ctl.entrysize = sizeof(ReorderBufferTupleCidEnt);
|
|
hash_ctl.hcxt = rb->context;
|
|
|
|
/*
|
|
* create the hash with the exact number of to-be-stored tuplecids from
|
|
* the start
|
|
*/
|
|
txn->tuplecid_hash =
|
|
hash_create("ReorderBufferTupleCid", txn->ntuplecids, &hash_ctl,
|
|
HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
|
|
|
|
dlist_foreach(iter, &txn->tuplecids)
|
|
{
|
|
ReorderBufferTupleCidKey key;
|
|
ReorderBufferTupleCidEnt *ent;
|
|
bool found;
|
|
ReorderBufferChange *change;
|
|
|
|
change = dlist_container(ReorderBufferChange, node, iter.cur);
|
|
|
|
Assert(change->action == REORDER_BUFFER_CHANGE_INTERNAL_TUPLECID);
|
|
|
|
/* be careful about padding */
|
|
memset(&key, 0, sizeof(ReorderBufferTupleCidKey));
|
|
|
|
key.relnode = change->data.tuplecid.node;
|
|
|
|
ItemPointerCopy(&change->data.tuplecid.tid,
|
|
&key.tid);
|
|
|
|
ent = (ReorderBufferTupleCidEnt *)
|
|
hash_search(txn->tuplecid_hash,
|
|
(void *) &key,
|
|
HASH_ENTER | HASH_FIND,
|
|
&found);
|
|
if (!found)
|
|
{
|
|
ent->cmin = change->data.tuplecid.cmin;
|
|
ent->cmax = change->data.tuplecid.cmax;
|
|
ent->combocid = change->data.tuplecid.combocid;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* Maybe we already saw this tuple before in this transaction, but
|
|
* if so it must have the same cmin.
|
|
*/
|
|
Assert(ent->cmin == change->data.tuplecid.cmin);
|
|
|
|
/*
|
|
* cmax may be initially invalid, but once set it can only grow,
|
|
* and never become invalid again.
|
|
*/
|
|
Assert((ent->cmax == InvalidCommandId) ||
|
|
((change->data.tuplecid.cmax != InvalidCommandId) &&
|
|
(change->data.tuplecid.cmax > ent->cmax)));
|
|
ent->cmax = change->data.tuplecid.cmax;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Copy a provided snapshot so we can modify it privately. This is needed so
|
|
* that catalog modifying transactions can look into intermediate catalog
|
|
* states.
|
|
*/
|
|
static Snapshot
|
|
ReorderBufferCopySnap(ReorderBuffer *rb, Snapshot orig_snap,
|
|
ReorderBufferTXN *txn, CommandId cid)
|
|
{
|
|
Snapshot snap;
|
|
dlist_iter iter;
|
|
int i = 0;
|
|
Size size;
|
|
|
|
size = sizeof(SnapshotData) +
|
|
sizeof(TransactionId) * orig_snap->xcnt +
|
|
sizeof(TransactionId) * (txn->nsubtxns + 1);
|
|
|
|
snap = MemoryContextAllocZero(rb->context, size);
|
|
memcpy(snap, orig_snap, sizeof(SnapshotData));
|
|
|
|
snap->copied = true;
|
|
snap->active_count = 1; /* mark as active so nobody frees it */
|
|
snap->regd_count = 0;
|
|
snap->xip = (TransactionId *) (snap + 1);
|
|
|
|
memcpy(snap->xip, orig_snap->xip, sizeof(TransactionId) * snap->xcnt);
|
|
|
|
/*
|
|
* snap->subxip contains all txids that belong to our transaction which we
|
|
* need to check via cmin/cmax. That's why we store the toplevel
|
|
* transaction in there as well.
|
|
*/
|
|
snap->subxip = snap->xip + snap->xcnt;
|
|
snap->subxip[i++] = txn->xid;
|
|
|
|
/*
|
|
* nsubxcnt isn't decreased when subtransactions abort, so count manually.
|
|
* Since it's an upper boundary it is safe to use it for the allocation
|
|
* above.
|
|
*/
|
|
snap->subxcnt = 1;
|
|
|
|
dlist_foreach(iter, &txn->subtxns)
|
|
{
|
|
ReorderBufferTXN *sub_txn;
|
|
|
|
sub_txn = dlist_container(ReorderBufferTXN, node, iter.cur);
|
|
snap->subxip[i++] = sub_txn->xid;
|
|
snap->subxcnt++;
|
|
}
|
|
|
|
/* sort so we can bsearch() later */
|
|
qsort(snap->subxip, snap->subxcnt, sizeof(TransactionId), xidComparator);
|
|
|
|
/* store the specified current CommandId */
|
|
snap->curcid = cid;
|
|
|
|
return snap;
|
|
}
|
|
|
|
/*
|
|
* Free a previously ReorderBufferCopySnap'ed snapshot
|
|
*/
|
|
static void
|
|
ReorderBufferFreeSnap(ReorderBuffer *rb, Snapshot snap)
|
|
{
|
|
if (snap->copied)
|
|
pfree(snap);
|
|
else
|
|
SnapBuildSnapDecRefcount(snap);
|
|
}
|
|
|
|
/*
|
|
* Perform the replay of a transaction and its non-aborted subtransactions.
|
|
*
|
|
* Subtransactions previously have to be processed by
|
|
* ReorderBufferCommitChild(), even if previously assigned to the toplevel
|
|
* transaction with ReorderBufferAssignChild.
|
|
*
|
|
* We currently can only decode a transaction's contents when its commit
|
|
* record is read because that's the only place where we know about cache
|
|
* invalidations. Thus, once a toplevel commit is read, we iterate over the top
|
|
* and subtransactions (using a k-way merge) and replay the changes in lsn
|
|
* order.
|
|
*/
|
|
void
|
|
ReorderBufferCommit(ReorderBuffer *rb, TransactionId xid,
|
|
XLogRecPtr commit_lsn, XLogRecPtr end_lsn,
|
|
TimestampTz commit_time,
|
|
RepOriginId origin_id, XLogRecPtr origin_lsn)
|
|
{
|
|
ReorderBufferTXN *txn;
|
|
volatile Snapshot snapshot_now;
|
|
volatile CommandId command_id = FirstCommandId;
|
|
bool using_subtxn;
|
|
ReorderBufferIterTXNState *volatile iterstate = NULL;
|
|
|
|
txn = ReorderBufferTXNByXid(rb, xid, false, NULL, InvalidXLogRecPtr,
|
|
false);
|
|
|
|
/* unknown transaction, nothing to replay */
|
|
if (txn == NULL)
|
|
return;
|
|
|
|
txn->final_lsn = commit_lsn;
|
|
txn->end_lsn = end_lsn;
|
|
txn->commit_time = commit_time;
|
|
txn->origin_id = origin_id;
|
|
txn->origin_lsn = origin_lsn;
|
|
|
|
/*
|
|
* If this transaction has no snapshot, it didn't make any changes to the
|
|
* database, so there's nothing to decode. Note that
|
|
* ReorderBufferCommitChild will have transferred any snapshots from
|
|
* subtransactions if there were any.
|
|
*/
|
|
if (txn->base_snapshot == NULL)
|
|
{
|
|
Assert(txn->ninvalidations == 0);
|
|
ReorderBufferCleanupTXN(rb, txn);
|
|
return;
|
|
}
|
|
|
|
snapshot_now = txn->base_snapshot;
|
|
|
|
/* build data to be able to lookup the CommandIds of catalog tuples */
|
|
ReorderBufferBuildTupleCidHash(rb, txn);
|
|
|
|
/* setup the initial snapshot */
|
|
SetupHistoricSnapshot(snapshot_now, txn->tuplecid_hash);
|
|
|
|
/*
|
|
* Decoding needs access to syscaches et al., which in turn use
|
|
* heavyweight locks and such. Thus we need to have enough state around to
|
|
* keep track of those. The easiest way is to simply use a transaction
|
|
* internally. That also allows us to easily enforce that nothing writes
|
|
* to the database by checking for xid assignments.
|
|
*
|
|
* When we're called via the SQL SRF there's already a transaction
|
|
* started, so start an explicit subtransaction there.
|
|
*/
|
|
using_subtxn = IsTransactionOrTransactionBlock();
|
|
|
|
PG_TRY();
|
|
{
|
|
ReorderBufferChange *change;
|
|
ReorderBufferChange *specinsert = NULL;
|
|
|
|
if (using_subtxn)
|
|
BeginInternalSubTransaction("replay");
|
|
else
|
|
StartTransactionCommand();
|
|
|
|
rb->begin(rb, txn);
|
|
|
|
iterstate = ReorderBufferIterTXNInit(rb, txn);
|
|
while ((change = ReorderBufferIterTXNNext(rb, iterstate)) != NULL)
|
|
{
|
|
Relation relation = NULL;
|
|
Oid reloid;
|
|
|
|
switch (change->action)
|
|
{
|
|
case REORDER_BUFFER_CHANGE_INTERNAL_SPEC_CONFIRM:
|
|
|
|
/*
|
|
* Confirmation for speculative insertion arrived. Simply
|
|
* use as a normal record. It'll be cleaned up at the end
|
|
* of INSERT processing.
|
|
*/
|
|
if (specinsert == NULL)
|
|
elog(ERROR, "invalid ordering of speculative insertion changes");
|
|
Assert(specinsert->data.tp.oldtuple == NULL);
|
|
change = specinsert;
|
|
change->action = REORDER_BUFFER_CHANGE_INSERT;
|
|
|
|
/* intentionally fall through */
|
|
case REORDER_BUFFER_CHANGE_INSERT:
|
|
case REORDER_BUFFER_CHANGE_UPDATE:
|
|
case REORDER_BUFFER_CHANGE_DELETE:
|
|
Assert(snapshot_now);
|
|
|
|
reloid = RelidByRelfilenode(change->data.tp.relnode.spcNode,
|
|
change->data.tp.relnode.relNode);
|
|
|
|
/*
|
|
* Mapped catalog tuple without data, emitted while
|
|
* catalog table was in the process of being rewritten. We
|
|
* can fail to look up the relfilenode, because the
|
|
* relmapper has no "historic" view, in contrast to normal
|
|
* the normal catalog during decoding. Thus repeated
|
|
* rewrites can cause a lookup failure. That's OK because
|
|
* we do not decode catalog changes anyway. Normally such
|
|
* tuples would be skipped over below, but we can't
|
|
* identify whether the table should be logically logged
|
|
* without mapping the relfilenode to the oid.
|
|
*/
|
|
if (reloid == InvalidOid &&
|
|
change->data.tp.newtuple == NULL &&
|
|
change->data.tp.oldtuple == NULL)
|
|
goto change_done;
|
|
else if (reloid == InvalidOid)
|
|
elog(ERROR, "could not map filenode \"%s\" to relation OID",
|
|
relpathperm(change->data.tp.relnode,
|
|
MAIN_FORKNUM));
|
|
|
|
relation = RelationIdGetRelation(reloid);
|
|
|
|
if (relation == NULL)
|
|
elog(ERROR, "could not open relation with OID %u (for filenode \"%s\")",
|
|
reloid,
|
|
relpathperm(change->data.tp.relnode,
|
|
MAIN_FORKNUM));
|
|
|
|
if (!RelationIsLogicallyLogged(relation))
|
|
goto change_done;
|
|
|
|
/*
|
|
* Ignore temporary heaps created during DDL unless the
|
|
* plugin has asked for them.
|
|
*/
|
|
if (relation->rd_rel->relrewrite && !rb->output_rewrites)
|
|
goto change_done;
|
|
|
|
/*
|
|
* For now ignore sequence changes entirely. Most of the
|
|
* time they don't log changes using records we
|
|
* understand, so it doesn't make sense to handle the few
|
|
* cases we do.
|
|
*/
|
|
if (relation->rd_rel->relkind == RELKIND_SEQUENCE)
|
|
goto change_done;
|
|
|
|
/* user-triggered change */
|
|
if (!IsToastRelation(relation))
|
|
{
|
|
ReorderBufferToastReplace(rb, txn, relation, change);
|
|
rb->apply_change(rb, txn, relation, change);
|
|
|
|
/*
|
|
* Only clear reassembled toast chunks if we're sure
|
|
* they're not required anymore. The creator of the
|
|
* tuple tells us.
|
|
*/
|
|
if (change->data.tp.clear_toast_afterwards)
|
|
ReorderBufferToastReset(rb, txn);
|
|
}
|
|
/* we're not interested in toast deletions */
|
|
else if (change->action == REORDER_BUFFER_CHANGE_INSERT)
|
|
{
|
|
/*
|
|
* Need to reassemble the full toasted Datum in
|
|
* memory, to ensure the chunks don't get reused till
|
|
* we're done remove it from the list of this
|
|
* transaction's changes. Otherwise it will get
|
|
* freed/reused while restoring spooled data from
|
|
* disk.
|
|
*/
|
|
Assert(change->data.tp.newtuple != NULL);
|
|
|
|
dlist_delete(&change->node);
|
|
ReorderBufferToastAppendChunk(rb, txn, relation,
|
|
change);
|
|
}
|
|
|
|
change_done:
|
|
|
|
/*
|
|
* Either speculative insertion was confirmed, or it was
|
|
* unsuccessful and the record isn't needed anymore.
|
|
*/
|
|
if (specinsert != NULL)
|
|
{
|
|
ReorderBufferReturnChange(rb, specinsert);
|
|
specinsert = NULL;
|
|
}
|
|
|
|
if (relation != NULL)
|
|
{
|
|
RelationClose(relation);
|
|
relation = NULL;
|
|
}
|
|
break;
|
|
|
|
case REORDER_BUFFER_CHANGE_INTERNAL_SPEC_INSERT:
|
|
|
|
/*
|
|
* Speculative insertions are dealt with by delaying the
|
|
* processing of the insert until the confirmation record
|
|
* arrives. For that we simply unlink the record from the
|
|
* chain, so it does not get freed/reused while restoring
|
|
* spooled data from disk.
|
|
*
|
|
* This is safe in the face of concurrent catalog changes
|
|
* because the relevant relation can't be changed between
|
|
* speculative insertion and confirmation due to
|
|
* CheckTableNotInUse() and locking.
|
|
*/
|
|
|
|
/* clear out a pending (and thus failed) speculation */
|
|
if (specinsert != NULL)
|
|
{
|
|
ReorderBufferReturnChange(rb, specinsert);
|
|
specinsert = NULL;
|
|
}
|
|
|
|
/* and memorize the pending insertion */
|
|
dlist_delete(&change->node);
|
|
specinsert = change;
|
|
break;
|
|
|
|
case REORDER_BUFFER_CHANGE_TRUNCATE:
|
|
{
|
|
int i;
|
|
int nrelids = change->data.truncate.nrelids;
|
|
int nrelations = 0;
|
|
Relation *relations;
|
|
|
|
relations = palloc0(nrelids * sizeof(Relation));
|
|
for (i = 0; i < nrelids; i++)
|
|
{
|
|
Oid relid = change->data.truncate.relids[i];
|
|
Relation relation;
|
|
|
|
relation = RelationIdGetRelation(relid);
|
|
|
|
if (relation == NULL)
|
|
elog(ERROR, "could not open relation with OID %u", relid);
|
|
|
|
if (!RelationIsLogicallyLogged(relation))
|
|
continue;
|
|
|
|
relations[nrelations++] = relation;
|
|
}
|
|
|
|
rb->apply_truncate(rb, txn, nrelations, relations, change);
|
|
|
|
for (i = 0; i < nrelations; i++)
|
|
RelationClose(relations[i]);
|
|
|
|
break;
|
|
}
|
|
|
|
case REORDER_BUFFER_CHANGE_MESSAGE:
|
|
rb->message(rb, txn, change->lsn, true,
|
|
change->data.msg.prefix,
|
|
change->data.msg.message_size,
|
|
change->data.msg.message);
|
|
break;
|
|
|
|
case REORDER_BUFFER_CHANGE_INTERNAL_SNAPSHOT:
|
|
/* get rid of the old */
|
|
TeardownHistoricSnapshot(false);
|
|
|
|
if (snapshot_now->copied)
|
|
{
|
|
ReorderBufferFreeSnap(rb, snapshot_now);
|
|
snapshot_now =
|
|
ReorderBufferCopySnap(rb, change->data.snapshot,
|
|
txn, command_id);
|
|
}
|
|
|
|
/*
|
|
* Restored from disk, need to be careful not to double
|
|
* free. We could introduce refcounting for that, but for
|
|
* now this seems infrequent enough not to care.
|
|
*/
|
|
else if (change->data.snapshot->copied)
|
|
{
|
|
snapshot_now =
|
|
ReorderBufferCopySnap(rb, change->data.snapshot,
|
|
txn, command_id);
|
|
}
|
|
else
|
|
{
|
|
snapshot_now = change->data.snapshot;
|
|
}
|
|
|
|
|
|
/* and continue with the new one */
|
|
SetupHistoricSnapshot(snapshot_now, txn->tuplecid_hash);
|
|
break;
|
|
|
|
case REORDER_BUFFER_CHANGE_INTERNAL_COMMAND_ID:
|
|
Assert(change->data.command_id != InvalidCommandId);
|
|
|
|
if (command_id < change->data.command_id)
|
|
{
|
|
command_id = change->data.command_id;
|
|
|
|
if (!snapshot_now->copied)
|
|
{
|
|
/* we don't use the global one anymore */
|
|
snapshot_now = ReorderBufferCopySnap(rb, snapshot_now,
|
|
txn, command_id);
|
|
}
|
|
|
|
snapshot_now->curcid = command_id;
|
|
|
|
TeardownHistoricSnapshot(false);
|
|
SetupHistoricSnapshot(snapshot_now, txn->tuplecid_hash);
|
|
|
|
/*
|
|
* Every time the CommandId is incremented, we could
|
|
* see new catalog contents, so execute all
|
|
* invalidations.
|
|
*/
|
|
ReorderBufferExecuteInvalidations(rb, txn);
|
|
}
|
|
|
|
break;
|
|
|
|
case REORDER_BUFFER_CHANGE_INTERNAL_TUPLECID:
|
|
elog(ERROR, "tuplecid value in changequeue");
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* There's a speculative insertion remaining, just clean in up, it
|
|
* can't have been successful, otherwise we'd gotten a confirmation
|
|
* record.
|
|
*/
|
|
if (specinsert)
|
|
{
|
|
ReorderBufferReturnChange(rb, specinsert);
|
|
specinsert = NULL;
|
|
}
|
|
|
|
/* clean up the iterator */
|
|
ReorderBufferIterTXNFinish(rb, iterstate);
|
|
iterstate = NULL;
|
|
|
|
/* call commit callback */
|
|
rb->commit(rb, txn, commit_lsn);
|
|
|
|
/* this is just a sanity check against bad output plugin behaviour */
|
|
if (GetCurrentTransactionIdIfAny() != InvalidTransactionId)
|
|
elog(ERROR, "output plugin used XID %u",
|
|
GetCurrentTransactionId());
|
|
|
|
/* cleanup */
|
|
TeardownHistoricSnapshot(false);
|
|
|
|
/*
|
|
* Aborting the current (sub-)transaction as a whole has the right
|
|
* semantics. We want all locks acquired in here to be released, not
|
|
* reassigned to the parent and we do not want any database access
|
|
* have persistent effects.
|
|
*/
|
|
AbortCurrentTransaction();
|
|
|
|
/* make sure there's no cache pollution */
|
|
ReorderBufferExecuteInvalidations(rb, txn);
|
|
|
|
if (using_subtxn)
|
|
RollbackAndReleaseCurrentSubTransaction();
|
|
|
|
if (snapshot_now->copied)
|
|
ReorderBufferFreeSnap(rb, snapshot_now);
|
|
|
|
/* remove potential on-disk data, and deallocate */
|
|
ReorderBufferCleanupTXN(rb, txn);
|
|
}
|
|
PG_CATCH();
|
|
{
|
|
/* TODO: Encapsulate cleanup from the PG_TRY and PG_CATCH blocks */
|
|
if (iterstate)
|
|
ReorderBufferIterTXNFinish(rb, iterstate);
|
|
|
|
TeardownHistoricSnapshot(true);
|
|
|
|
/*
|
|
* Force cache invalidation to happen outside of a valid transaction
|
|
* to prevent catalog access as we just caught an error.
|
|
*/
|
|
AbortCurrentTransaction();
|
|
|
|
/* make sure there's no cache pollution */
|
|
ReorderBufferExecuteInvalidations(rb, txn);
|
|
|
|
if (using_subtxn)
|
|
RollbackAndReleaseCurrentSubTransaction();
|
|
|
|
if (snapshot_now->copied)
|
|
ReorderBufferFreeSnap(rb, snapshot_now);
|
|
|
|
/* remove potential on-disk data, and deallocate */
|
|
ReorderBufferCleanupTXN(rb, txn);
|
|
|
|
PG_RE_THROW();
|
|
}
|
|
PG_END_TRY();
|
|
}
|
|
|
|
/*
|
|
* Abort a transaction that possibly has previous changes. Needs to be first
|
|
* called for subtransactions and then for the toplevel xid.
|
|
*
|
|
* NB: Transactions handled here have to have actively aborted (i.e. have
|
|
* produced an abort record). Implicitly aborted transactions are handled via
|
|
* ReorderBufferAbortOld(); transactions we're just not interested in, but
|
|
* which have committed are handled in ReorderBufferForget().
|
|
*
|
|
* This function purges this transaction and its contents from memory and
|
|
* disk.
|
|
*/
|
|
void
|
|
ReorderBufferAbort(ReorderBuffer *rb, TransactionId xid, XLogRecPtr lsn)
|
|
{
|
|
ReorderBufferTXN *txn;
|
|
|
|
txn = ReorderBufferTXNByXid(rb, xid, false, NULL, InvalidXLogRecPtr,
|
|
false);
|
|
|
|
/* unknown, nothing to remove */
|
|
if (txn == NULL)
|
|
return;
|
|
|
|
/* cosmetic... */
|
|
txn->final_lsn = lsn;
|
|
|
|
/* remove potential on-disk data, and deallocate */
|
|
ReorderBufferCleanupTXN(rb, txn);
|
|
}
|
|
|
|
/*
|
|
* Abort all transactions that aren't actually running anymore because the
|
|
* server restarted.
|
|
*
|
|
* NB: These really have to be transactions that have aborted due to a server
|
|
* crash/immediate restart, as we don't deal with invalidations here.
|
|
*/
|
|
void
|
|
ReorderBufferAbortOld(ReorderBuffer *rb, TransactionId oldestRunningXid)
|
|
{
|
|
dlist_mutable_iter it;
|
|
|
|
/*
|
|
* Iterate through all (potential) toplevel TXNs and abort all that are
|
|
* older than what possibly can be running. Once we've found the first
|
|
* that is alive we stop, there might be some that acquired an xid earlier
|
|
* but started writing later, but it's unlikely and they will be cleaned
|
|
* up in a later call to this function.
|
|
*/
|
|
dlist_foreach_modify(it, &rb->toplevel_by_lsn)
|
|
{
|
|
ReorderBufferTXN *txn;
|
|
|
|
txn = dlist_container(ReorderBufferTXN, node, it.cur);
|
|
|
|
if (TransactionIdPrecedes(txn->xid, oldestRunningXid))
|
|
{
|
|
/*
|
|
* We set final_lsn on a transaction when we decode its commit or
|
|
* abort record, but we never see those records for crashed
|
|
* transactions. To ensure cleanup of these transactions, set
|
|
* final_lsn to that of their last change; this causes
|
|
* ReorderBufferRestoreCleanup to do the right thing.
|
|
*/
|
|
if (txn->serialized && txn->final_lsn == 0)
|
|
{
|
|
ReorderBufferChange *last =
|
|
dlist_tail_element(ReorderBufferChange, node, &txn->changes);
|
|
|
|
txn->final_lsn = last->lsn;
|
|
}
|
|
|
|
elog(DEBUG2, "aborting old transaction %u", txn->xid);
|
|
|
|
/* remove potential on-disk data, and deallocate this tx */
|
|
ReorderBufferCleanupTXN(rb, txn);
|
|
}
|
|
else
|
|
return;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Forget the contents of a transaction if we aren't interested in it's
|
|
* contents. Needs to be first called for subtransactions and then for the
|
|
* toplevel xid.
|
|
*
|
|
* This is significantly different to ReorderBufferAbort() because
|
|
* transactions that have committed need to be treated differently from aborted
|
|
* ones since they may have modified the catalog.
|
|
*
|
|
* Note that this is only allowed to be called in the moment a transaction
|
|
* commit has just been read, not earlier; otherwise later records referring
|
|
* to this xid might re-create the transaction incompletely.
|
|
*/
|
|
void
|
|
ReorderBufferForget(ReorderBuffer *rb, TransactionId xid, XLogRecPtr lsn)
|
|
{
|
|
ReorderBufferTXN *txn;
|
|
|
|
txn = ReorderBufferTXNByXid(rb, xid, false, NULL, InvalidXLogRecPtr,
|
|
false);
|
|
|
|
/* unknown, nothing to forget */
|
|
if (txn == NULL)
|
|
return;
|
|
|
|
/* cosmetic... */
|
|
txn->final_lsn = lsn;
|
|
|
|
/*
|
|
* Process cache invalidation messages if there are any. Even if we're not
|
|
* interested in the transaction's contents, it could have manipulated the
|
|
* catalog and we need to update the caches according to that.
|
|
*/
|
|
if (txn->base_snapshot != NULL && txn->ninvalidations > 0)
|
|
ReorderBufferImmediateInvalidation(rb, txn->ninvalidations,
|
|
txn->invalidations);
|
|
else
|
|
Assert(txn->ninvalidations == 0);
|
|
|
|
/* remove potential on-disk data, and deallocate */
|
|
ReorderBufferCleanupTXN(rb, txn);
|
|
}
|
|
|
|
/*
|
|
* Execute invalidations happening outside the context of a decoded
|
|
* transaction. That currently happens either for xid-less commits
|
|
* (cf. RecordTransactionCommit()) or for invalidations in uninteresting
|
|
* transactions (via ReorderBufferForget()).
|
|
*/
|
|
void
|
|
ReorderBufferImmediateInvalidation(ReorderBuffer *rb, uint32 ninvalidations,
|
|
SharedInvalidationMessage *invalidations)
|
|
{
|
|
bool use_subtxn = IsTransactionOrTransactionBlock();
|
|
int i;
|
|
|
|
if (use_subtxn)
|
|
BeginInternalSubTransaction("replay");
|
|
|
|
/*
|
|
* Force invalidations to happen outside of a valid transaction - that way
|
|
* entries will just be marked as invalid without accessing the catalog.
|
|
* That's advantageous because we don't need to setup the full state
|
|
* necessary for catalog access.
|
|
*/
|
|
if (use_subtxn)
|
|
AbortCurrentTransaction();
|
|
|
|
for (i = 0; i < ninvalidations; i++)
|
|
LocalExecuteInvalidationMessage(&invalidations[i]);
|
|
|
|
if (use_subtxn)
|
|
RollbackAndReleaseCurrentSubTransaction();
|
|
}
|
|
|
|
/*
|
|
* Tell reorderbuffer about an xid seen in the WAL stream. Has to be called at
|
|
* least once for every xid in XLogRecord->xl_xid (other places in records
|
|
* may, but do not have to be passed through here).
|
|
*
|
|
* Reorderbuffer keeps some datastructures about transactions in LSN order,
|
|
* for efficiency. To do that it has to know about when transactions are seen
|
|
* first in the WAL. As many types of records are not actually interesting for
|
|
* logical decoding, they do not necessarily pass though here.
|
|
*/
|
|
void
|
|
ReorderBufferProcessXid(ReorderBuffer *rb, TransactionId xid, XLogRecPtr lsn)
|
|
{
|
|
/* many records won't have an xid assigned, centralize check here */
|
|
if (xid != InvalidTransactionId)
|
|
ReorderBufferTXNByXid(rb, xid, true, NULL, lsn, true);
|
|
}
|
|
|
|
/*
|
|
* Add a new snapshot to this transaction that may only used after lsn 'lsn'
|
|
* because the previous snapshot doesn't describe the catalog correctly for
|
|
* following rows.
|
|
*/
|
|
void
|
|
ReorderBufferAddSnapshot(ReorderBuffer *rb, TransactionId xid,
|
|
XLogRecPtr lsn, Snapshot snap)
|
|
{
|
|
ReorderBufferChange *change = ReorderBufferGetChange(rb);
|
|
|
|
change->data.snapshot = snap;
|
|
change->action = REORDER_BUFFER_CHANGE_INTERNAL_SNAPSHOT;
|
|
|
|
ReorderBufferQueueChange(rb, xid, lsn, change);
|
|
}
|
|
|
|
/*
|
|
* Set up the transaction's base snapshot.
|
|
*
|
|
* If we know that xid is a subtransaction, set the base snapshot on the
|
|
* top-level transaction instead.
|
|
*/
|
|
void
|
|
ReorderBufferSetBaseSnapshot(ReorderBuffer *rb, TransactionId xid,
|
|
XLogRecPtr lsn, Snapshot snap)
|
|
{
|
|
ReorderBufferTXN *txn;
|
|
bool is_new;
|
|
|
|
AssertArg(snap != NULL);
|
|
|
|
/*
|
|
* Fetch the transaction to operate on. If we know it's a subtransaction,
|
|
* operate on its top-level transaction instead.
|
|
*/
|
|
txn = ReorderBufferTXNByXid(rb, xid, true, &is_new, lsn, true);
|
|
if (txn->is_known_as_subxact)
|
|
txn = ReorderBufferTXNByXid(rb, txn->toplevel_xid, false,
|
|
NULL, InvalidXLogRecPtr, false);
|
|
Assert(txn->base_snapshot == NULL);
|
|
|
|
txn->base_snapshot = snap;
|
|
txn->base_snapshot_lsn = lsn;
|
|
dlist_push_tail(&rb->txns_by_base_snapshot_lsn, &txn->base_snapshot_node);
|
|
|
|
AssertTXNLsnOrder(rb);
|
|
}
|
|
|
|
/*
|
|
* Access the catalog with this CommandId at this point in the changestream.
|
|
*
|
|
* May only be called for command ids > 1
|
|
*/
|
|
void
|
|
ReorderBufferAddNewCommandId(ReorderBuffer *rb, TransactionId xid,
|
|
XLogRecPtr lsn, CommandId cid)
|
|
{
|
|
ReorderBufferChange *change = ReorderBufferGetChange(rb);
|
|
|
|
change->data.command_id = cid;
|
|
change->action = REORDER_BUFFER_CHANGE_INTERNAL_COMMAND_ID;
|
|
|
|
ReorderBufferQueueChange(rb, xid, lsn, change);
|
|
}
|
|
|
|
|
|
/*
|
|
* Add new (relfilenode, tid) -> (cmin, cmax) mappings.
|
|
*/
|
|
void
|
|
ReorderBufferAddNewTupleCids(ReorderBuffer *rb, TransactionId xid,
|
|
XLogRecPtr lsn, RelFileNode node,
|
|
ItemPointerData tid, CommandId cmin,
|
|
CommandId cmax, CommandId combocid)
|
|
{
|
|
ReorderBufferChange *change = ReorderBufferGetChange(rb);
|
|
ReorderBufferTXN *txn;
|
|
|
|
txn = ReorderBufferTXNByXid(rb, xid, true, NULL, lsn, true);
|
|
|
|
change->data.tuplecid.node = node;
|
|
change->data.tuplecid.tid = tid;
|
|
change->data.tuplecid.cmin = cmin;
|
|
change->data.tuplecid.cmax = cmax;
|
|
change->data.tuplecid.combocid = combocid;
|
|
change->lsn = lsn;
|
|
change->action = REORDER_BUFFER_CHANGE_INTERNAL_TUPLECID;
|
|
|
|
dlist_push_tail(&txn->tuplecids, &change->node);
|
|
txn->ntuplecids++;
|
|
}
|
|
|
|
/*
|
|
* Setup the invalidation of the toplevel transaction.
|
|
*
|
|
* This needs to be done before ReorderBufferCommit is called!
|
|
*/
|
|
void
|
|
ReorderBufferAddInvalidations(ReorderBuffer *rb, TransactionId xid,
|
|
XLogRecPtr lsn, Size nmsgs,
|
|
SharedInvalidationMessage *msgs)
|
|
{
|
|
ReorderBufferTXN *txn;
|
|
|
|
txn = ReorderBufferTXNByXid(rb, xid, true, NULL, lsn, true);
|
|
|
|
if (txn->ninvalidations != 0)
|
|
elog(ERROR, "only ever add one set of invalidations");
|
|
|
|
Assert(nmsgs > 0);
|
|
|
|
txn->ninvalidations = nmsgs;
|
|
txn->invalidations = (SharedInvalidationMessage *)
|
|
MemoryContextAlloc(rb->context,
|
|
sizeof(SharedInvalidationMessage) * nmsgs);
|
|
memcpy(txn->invalidations, msgs,
|
|
sizeof(SharedInvalidationMessage) * nmsgs);
|
|
}
|
|
|
|
/*
|
|
* Apply all invalidations we know. Possibly we only need parts at this point
|
|
* in the changestream but we don't know which those are.
|
|
*/
|
|
static void
|
|
ReorderBufferExecuteInvalidations(ReorderBuffer *rb, ReorderBufferTXN *txn)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < txn->ninvalidations; i++)
|
|
LocalExecuteInvalidationMessage(&txn->invalidations[i]);
|
|
}
|
|
|
|
/*
|
|
* Mark a transaction as containing catalog changes
|
|
*/
|
|
void
|
|
ReorderBufferXidSetCatalogChanges(ReorderBuffer *rb, TransactionId xid,
|
|
XLogRecPtr lsn)
|
|
{
|
|
ReorderBufferTXN *txn;
|
|
|
|
txn = ReorderBufferTXNByXid(rb, xid, true, NULL, lsn, true);
|
|
|
|
txn->has_catalog_changes = true;
|
|
}
|
|
|
|
/*
|
|
* Query whether a transaction is already *known* to contain catalog
|
|
* changes. This can be wrong until directly before the commit!
|
|
*/
|
|
bool
|
|
ReorderBufferXidHasCatalogChanges(ReorderBuffer *rb, TransactionId xid)
|
|
{
|
|
ReorderBufferTXN *txn;
|
|
|
|
txn = ReorderBufferTXNByXid(rb, xid, false, NULL, InvalidXLogRecPtr,
|
|
false);
|
|
if (txn == NULL)
|
|
return false;
|
|
|
|
return txn->has_catalog_changes;
|
|
}
|
|
|
|
/*
|
|
* ReorderBufferXidHasBaseSnapshot
|
|
* Have we already set the base snapshot for the given txn/subtxn?
|
|
*/
|
|
bool
|
|
ReorderBufferXidHasBaseSnapshot(ReorderBuffer *rb, TransactionId xid)
|
|
{
|
|
ReorderBufferTXN *txn;
|
|
|
|
txn = ReorderBufferTXNByXid(rb, xid, false,
|
|
NULL, InvalidXLogRecPtr, false);
|
|
|
|
/* transaction isn't known yet, ergo no snapshot */
|
|
if (txn == NULL)
|
|
return false;
|
|
|
|
/* a known subtxn? operate on top-level txn instead */
|
|
if (txn->is_known_as_subxact)
|
|
txn = ReorderBufferTXNByXid(rb, txn->toplevel_xid, false,
|
|
NULL, InvalidXLogRecPtr, false);
|
|
|
|
return txn->base_snapshot != NULL;
|
|
}
|
|
|
|
|
|
/*
|
|
* ---------------------------------------
|
|
* Disk serialization support
|
|
* ---------------------------------------
|
|
*/
|
|
|
|
/*
|
|
* Ensure the IO buffer is >= sz.
|
|
*/
|
|
static void
|
|
ReorderBufferSerializeReserve(ReorderBuffer *rb, Size sz)
|
|
{
|
|
if (!rb->outbufsize)
|
|
{
|
|
rb->outbuf = MemoryContextAlloc(rb->context, sz);
|
|
rb->outbufsize = sz;
|
|
}
|
|
else if (rb->outbufsize < sz)
|
|
{
|
|
rb->outbuf = repalloc(rb->outbuf, sz);
|
|
rb->outbufsize = sz;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Check whether the transaction tx should spill its data to disk.
|
|
*/
|
|
static void
|
|
ReorderBufferCheckSerializeTXN(ReorderBuffer *rb, ReorderBufferTXN *txn)
|
|
{
|
|
/*
|
|
* TODO: improve accounting so we cheaply can take subtransactions into
|
|
* account here.
|
|
*/
|
|
if (txn->nentries_mem >= max_changes_in_memory)
|
|
{
|
|
ReorderBufferSerializeTXN(rb, txn);
|
|
Assert(txn->nentries_mem == 0);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Spill data of a large transaction (and its subtransactions) to disk.
|
|
*/
|
|
static void
|
|
ReorderBufferSerializeTXN(ReorderBuffer *rb, ReorderBufferTXN *txn)
|
|
{
|
|
dlist_iter subtxn_i;
|
|
dlist_mutable_iter change_i;
|
|
int fd = -1;
|
|
XLogSegNo curOpenSegNo = 0;
|
|
Size spilled = 0;
|
|
|
|
elog(DEBUG2, "spill %u changes in XID %u to disk",
|
|
(uint32) txn->nentries_mem, txn->xid);
|
|
|
|
/* do the same to all child TXs */
|
|
dlist_foreach(subtxn_i, &txn->subtxns)
|
|
{
|
|
ReorderBufferTXN *subtxn;
|
|
|
|
subtxn = dlist_container(ReorderBufferTXN, node, subtxn_i.cur);
|
|
ReorderBufferSerializeTXN(rb, subtxn);
|
|
}
|
|
|
|
/* serialize changestream */
|
|
dlist_foreach_modify(change_i, &txn->changes)
|
|
{
|
|
ReorderBufferChange *change;
|
|
|
|
change = dlist_container(ReorderBufferChange, node, change_i.cur);
|
|
|
|
/*
|
|
* store in segment in which it belongs by start lsn, don't split over
|
|
* multiple segments tho
|
|
*/
|
|
if (fd == -1 ||
|
|
!XLByteInSeg(change->lsn, curOpenSegNo, wal_segment_size))
|
|
{
|
|
char path[MAXPGPATH];
|
|
|
|
if (fd != -1)
|
|
CloseTransientFile(fd);
|
|
|
|
XLByteToSeg(change->lsn, curOpenSegNo, wal_segment_size);
|
|
|
|
/*
|
|
* No need to care about TLIs here, only used during a single run,
|
|
* so each LSN only maps to a specific WAL record.
|
|
*/
|
|
ReorderBufferSerializedPath(path, MyReplicationSlot, txn->xid,
|
|
curOpenSegNo);
|
|
|
|
/* open segment, create it if necessary */
|
|
fd = OpenTransientFile(path,
|
|
O_CREAT | O_WRONLY | O_APPEND | PG_BINARY);
|
|
|
|
if (fd < 0)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open file \"%s\": %m", path)));
|
|
}
|
|
|
|
ReorderBufferSerializeChange(rb, txn, fd, change);
|
|
dlist_delete(&change->node);
|
|
ReorderBufferReturnChange(rb, change);
|
|
|
|
spilled++;
|
|
}
|
|
|
|
Assert(spilled == txn->nentries_mem);
|
|
Assert(dlist_is_empty(&txn->changes));
|
|
txn->nentries_mem = 0;
|
|
txn->serialized = true;
|
|
|
|
if (fd != -1)
|
|
CloseTransientFile(fd);
|
|
}
|
|
|
|
/*
|
|
* Serialize individual change to disk.
|
|
*/
|
|
static void
|
|
ReorderBufferSerializeChange(ReorderBuffer *rb, ReorderBufferTXN *txn,
|
|
int fd, ReorderBufferChange *change)
|
|
{
|
|
ReorderBufferDiskChange *ondisk;
|
|
Size sz = sizeof(ReorderBufferDiskChange);
|
|
|
|
ReorderBufferSerializeReserve(rb, sz);
|
|
|
|
ondisk = (ReorderBufferDiskChange *) rb->outbuf;
|
|
memcpy(&ondisk->change, change, sizeof(ReorderBufferChange));
|
|
|
|
switch (change->action)
|
|
{
|
|
/* fall through these, they're all similar enough */
|
|
case REORDER_BUFFER_CHANGE_INSERT:
|
|
case REORDER_BUFFER_CHANGE_UPDATE:
|
|
case REORDER_BUFFER_CHANGE_DELETE:
|
|
case REORDER_BUFFER_CHANGE_INTERNAL_SPEC_INSERT:
|
|
{
|
|
char *data;
|
|
ReorderBufferTupleBuf *oldtup,
|
|
*newtup;
|
|
Size oldlen = 0;
|
|
Size newlen = 0;
|
|
|
|
oldtup = change->data.tp.oldtuple;
|
|
newtup = change->data.tp.newtuple;
|
|
|
|
if (oldtup)
|
|
{
|
|
sz += sizeof(HeapTupleData);
|
|
oldlen = oldtup->tuple.t_len;
|
|
sz += oldlen;
|
|
}
|
|
|
|
if (newtup)
|
|
{
|
|
sz += sizeof(HeapTupleData);
|
|
newlen = newtup->tuple.t_len;
|
|
sz += newlen;
|
|
}
|
|
|
|
/* make sure we have enough space */
|
|
ReorderBufferSerializeReserve(rb, sz);
|
|
|
|
data = ((char *) rb->outbuf) + sizeof(ReorderBufferDiskChange);
|
|
/* might have been reallocated above */
|
|
ondisk = (ReorderBufferDiskChange *) rb->outbuf;
|
|
|
|
if (oldlen)
|
|
{
|
|
memcpy(data, &oldtup->tuple, sizeof(HeapTupleData));
|
|
data += sizeof(HeapTupleData);
|
|
|
|
memcpy(data, oldtup->tuple.t_data, oldlen);
|
|
data += oldlen;
|
|
}
|
|
|
|
if (newlen)
|
|
{
|
|
memcpy(data, &newtup->tuple, sizeof(HeapTupleData));
|
|
data += sizeof(HeapTupleData);
|
|
|
|
memcpy(data, newtup->tuple.t_data, newlen);
|
|
data += newlen;
|
|
}
|
|
break;
|
|
}
|
|
case REORDER_BUFFER_CHANGE_MESSAGE:
|
|
{
|
|
char *data;
|
|
Size prefix_size = strlen(change->data.msg.prefix) + 1;
|
|
|
|
sz += prefix_size + change->data.msg.message_size +
|
|
sizeof(Size) + sizeof(Size);
|
|
ReorderBufferSerializeReserve(rb, sz);
|
|
|
|
data = ((char *) rb->outbuf) + sizeof(ReorderBufferDiskChange);
|
|
|
|
/* might have been reallocated above */
|
|
ondisk = (ReorderBufferDiskChange *) rb->outbuf;
|
|
|
|
/* write the prefix including the size */
|
|
memcpy(data, &prefix_size, sizeof(Size));
|
|
data += sizeof(Size);
|
|
memcpy(data, change->data.msg.prefix,
|
|
prefix_size);
|
|
data += prefix_size;
|
|
|
|
/* write the message including the size */
|
|
memcpy(data, &change->data.msg.message_size, sizeof(Size));
|
|
data += sizeof(Size);
|
|
memcpy(data, change->data.msg.message,
|
|
change->data.msg.message_size);
|
|
data += change->data.msg.message_size;
|
|
|
|
break;
|
|
}
|
|
case REORDER_BUFFER_CHANGE_INTERNAL_SNAPSHOT:
|
|
{
|
|
Snapshot snap;
|
|
char *data;
|
|
|
|
snap = change->data.snapshot;
|
|
|
|
sz += sizeof(SnapshotData) +
|
|
sizeof(TransactionId) * snap->xcnt +
|
|
sizeof(TransactionId) * snap->subxcnt
|
|
;
|
|
|
|
/* make sure we have enough space */
|
|
ReorderBufferSerializeReserve(rb, sz);
|
|
data = ((char *) rb->outbuf) + sizeof(ReorderBufferDiskChange);
|
|
/* might have been reallocated above */
|
|
ondisk = (ReorderBufferDiskChange *) rb->outbuf;
|
|
|
|
memcpy(data, snap, sizeof(SnapshotData));
|
|
data += sizeof(SnapshotData);
|
|
|
|
if (snap->xcnt)
|
|
{
|
|
memcpy(data, snap->xip,
|
|
sizeof(TransactionId) * snap->xcnt);
|
|
data += sizeof(TransactionId) * snap->xcnt;
|
|
}
|
|
|
|
if (snap->subxcnt)
|
|
{
|
|
memcpy(data, snap->subxip,
|
|
sizeof(TransactionId) * snap->subxcnt);
|
|
data += sizeof(TransactionId) * snap->subxcnt;
|
|
}
|
|
break;
|
|
}
|
|
case REORDER_BUFFER_CHANGE_TRUNCATE:
|
|
{
|
|
Size size;
|
|
char *data;
|
|
|
|
/* account for the OIDs of truncated relations */
|
|
size = sizeof(Oid) * change->data.truncate.nrelids;
|
|
sz += size;
|
|
|
|
/* make sure we have enough space */
|
|
ReorderBufferSerializeReserve(rb, sz);
|
|
|
|
data = ((char *) rb->outbuf) + sizeof(ReorderBufferDiskChange);
|
|
/* might have been reallocated above */
|
|
ondisk = (ReorderBufferDiskChange *) rb->outbuf;
|
|
|
|
memcpy(data, change->data.truncate.relids, size);
|
|
data += size;
|
|
|
|
break;
|
|
}
|
|
case REORDER_BUFFER_CHANGE_INTERNAL_SPEC_CONFIRM:
|
|
case REORDER_BUFFER_CHANGE_INTERNAL_COMMAND_ID:
|
|
case REORDER_BUFFER_CHANGE_INTERNAL_TUPLECID:
|
|
/* ReorderBufferChange contains everything important */
|
|
break;
|
|
}
|
|
|
|
ondisk->size = sz;
|
|
|
|
errno = 0;
|
|
pgstat_report_wait_start(WAIT_EVENT_REORDER_BUFFER_WRITE);
|
|
if (write(fd, rb->outbuf, ondisk->size) != ondisk->size)
|
|
{
|
|
int save_errno = errno;
|
|
|
|
CloseTransientFile(fd);
|
|
|
|
/* if write didn't set errno, assume problem is no disk space */
|
|
errno = save_errno ? save_errno : ENOSPC;
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not write to data file for XID %u: %m",
|
|
txn->xid)));
|
|
}
|
|
pgstat_report_wait_end();
|
|
|
|
Assert(ondisk->change.action == change->action);
|
|
}
|
|
|
|
/*
|
|
* Restore a number of changes spilled to disk back into memory.
|
|
*/
|
|
static Size
|
|
ReorderBufferRestoreChanges(ReorderBuffer *rb, ReorderBufferTXN *txn,
|
|
int *fd, XLogSegNo *segno)
|
|
{
|
|
Size restored = 0;
|
|
XLogSegNo last_segno;
|
|
dlist_mutable_iter cleanup_iter;
|
|
|
|
Assert(txn->first_lsn != InvalidXLogRecPtr);
|
|
Assert(txn->final_lsn != InvalidXLogRecPtr);
|
|
|
|
/* free current entries, so we have memory for more */
|
|
dlist_foreach_modify(cleanup_iter, &txn->changes)
|
|
{
|
|
ReorderBufferChange *cleanup =
|
|
dlist_container(ReorderBufferChange, node, cleanup_iter.cur);
|
|
|
|
dlist_delete(&cleanup->node);
|
|
ReorderBufferReturnChange(rb, cleanup);
|
|
}
|
|
txn->nentries_mem = 0;
|
|
Assert(dlist_is_empty(&txn->changes));
|
|
|
|
XLByteToSeg(txn->final_lsn, last_segno, wal_segment_size);
|
|
|
|
while (restored < max_changes_in_memory && *segno <= last_segno)
|
|
{
|
|
int readBytes;
|
|
ReorderBufferDiskChange *ondisk;
|
|
|
|
if (*fd == -1)
|
|
{
|
|
char path[MAXPGPATH];
|
|
|
|
/* first time in */
|
|
if (*segno == 0)
|
|
XLByteToSeg(txn->first_lsn, *segno, wal_segment_size);
|
|
|
|
Assert(*segno != 0 || dlist_is_empty(&txn->changes));
|
|
|
|
/*
|
|
* No need to care about TLIs here, only used during a single run,
|
|
* so each LSN only maps to a specific WAL record.
|
|
*/
|
|
ReorderBufferSerializedPath(path, MyReplicationSlot, txn->xid,
|
|
*segno);
|
|
|
|
*fd = OpenTransientFile(path, O_RDONLY | PG_BINARY);
|
|
if (*fd < 0 && errno == ENOENT)
|
|
{
|
|
*fd = -1;
|
|
(*segno)++;
|
|
continue;
|
|
}
|
|
else if (*fd < 0)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open file \"%s\": %m",
|
|
path)));
|
|
}
|
|
|
|
/*
|
|
* Read the statically sized part of a change which has information
|
|
* about the total size. If we couldn't read a record, we're at the
|
|
* end of this file.
|
|
*/
|
|
ReorderBufferSerializeReserve(rb, sizeof(ReorderBufferDiskChange));
|
|
pgstat_report_wait_start(WAIT_EVENT_REORDER_BUFFER_READ);
|
|
readBytes = read(*fd, rb->outbuf, sizeof(ReorderBufferDiskChange));
|
|
pgstat_report_wait_end();
|
|
|
|
/* eof */
|
|
if (readBytes == 0)
|
|
{
|
|
CloseTransientFile(*fd);
|
|
*fd = -1;
|
|
(*segno)++;
|
|
continue;
|
|
}
|
|
else if (readBytes < 0)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read from reorderbuffer spill file: %m")));
|
|
else if (readBytes != sizeof(ReorderBufferDiskChange))
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read from reorderbuffer spill file: read %d instead of %u bytes",
|
|
readBytes,
|
|
(uint32) sizeof(ReorderBufferDiskChange))));
|
|
|
|
ondisk = (ReorderBufferDiskChange *) rb->outbuf;
|
|
|
|
ReorderBufferSerializeReserve(rb,
|
|
sizeof(ReorderBufferDiskChange) + ondisk->size);
|
|
ondisk = (ReorderBufferDiskChange *) rb->outbuf;
|
|
|
|
pgstat_report_wait_start(WAIT_EVENT_REORDER_BUFFER_READ);
|
|
readBytes = read(*fd, rb->outbuf + sizeof(ReorderBufferDiskChange),
|
|
ondisk->size - sizeof(ReorderBufferDiskChange));
|
|
pgstat_report_wait_end();
|
|
|
|
if (readBytes < 0)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read from reorderbuffer spill file: %m")));
|
|
else if (readBytes != ondisk->size - sizeof(ReorderBufferDiskChange))
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read from reorderbuffer spill file: read %d instead of %u bytes",
|
|
readBytes,
|
|
(uint32) (ondisk->size - sizeof(ReorderBufferDiskChange)))));
|
|
|
|
/*
|
|
* ok, read a full change from disk, now restore it into proper
|
|
* in-memory format
|
|
*/
|
|
ReorderBufferRestoreChange(rb, txn, rb->outbuf);
|
|
restored++;
|
|
}
|
|
|
|
return restored;
|
|
}
|
|
|
|
/*
|
|
* Convert change from its on-disk format to in-memory format and queue it onto
|
|
* the TXN's ->changes list.
|
|
*
|
|
* Note: although "data" is declared char*, at entry it points to a
|
|
* maxalign'd buffer, making it safe in most of this function to assume
|
|
* that the pointed-to data is suitably aligned for direct access.
|
|
*/
|
|
static void
|
|
ReorderBufferRestoreChange(ReorderBuffer *rb, ReorderBufferTXN *txn,
|
|
char *data)
|
|
{
|
|
ReorderBufferDiskChange *ondisk;
|
|
ReorderBufferChange *change;
|
|
|
|
ondisk = (ReorderBufferDiskChange *) data;
|
|
|
|
change = ReorderBufferGetChange(rb);
|
|
|
|
/* copy static part */
|
|
memcpy(change, &ondisk->change, sizeof(ReorderBufferChange));
|
|
|
|
data += sizeof(ReorderBufferDiskChange);
|
|
|
|
/* restore individual stuff */
|
|
switch (change->action)
|
|
{
|
|
/* fall through these, they're all similar enough */
|
|
case REORDER_BUFFER_CHANGE_INSERT:
|
|
case REORDER_BUFFER_CHANGE_UPDATE:
|
|
case REORDER_BUFFER_CHANGE_DELETE:
|
|
case REORDER_BUFFER_CHANGE_INTERNAL_SPEC_INSERT:
|
|
if (change->data.tp.oldtuple)
|
|
{
|
|
uint32 tuplelen = ((HeapTuple) data)->t_len;
|
|
|
|
change->data.tp.oldtuple =
|
|
ReorderBufferGetTupleBuf(rb, tuplelen - SizeofHeapTupleHeader);
|
|
|
|
/* restore ->tuple */
|
|
memcpy(&change->data.tp.oldtuple->tuple, data,
|
|
sizeof(HeapTupleData));
|
|
data += sizeof(HeapTupleData);
|
|
|
|
/* reset t_data pointer into the new tuplebuf */
|
|
change->data.tp.oldtuple->tuple.t_data =
|
|
ReorderBufferTupleBufData(change->data.tp.oldtuple);
|
|
|
|
/* restore tuple data itself */
|
|
memcpy(change->data.tp.oldtuple->tuple.t_data, data, tuplelen);
|
|
data += tuplelen;
|
|
}
|
|
|
|
if (change->data.tp.newtuple)
|
|
{
|
|
/* here, data might not be suitably aligned! */
|
|
uint32 tuplelen;
|
|
|
|
memcpy(&tuplelen, data + offsetof(HeapTupleData, t_len),
|
|
sizeof(uint32));
|
|
|
|
change->data.tp.newtuple =
|
|
ReorderBufferGetTupleBuf(rb, tuplelen - SizeofHeapTupleHeader);
|
|
|
|
/* restore ->tuple */
|
|
memcpy(&change->data.tp.newtuple->tuple, data,
|
|
sizeof(HeapTupleData));
|
|
data += sizeof(HeapTupleData);
|
|
|
|
/* reset t_data pointer into the new tuplebuf */
|
|
change->data.tp.newtuple->tuple.t_data =
|
|
ReorderBufferTupleBufData(change->data.tp.newtuple);
|
|
|
|
/* restore tuple data itself */
|
|
memcpy(change->data.tp.newtuple->tuple.t_data, data, tuplelen);
|
|
data += tuplelen;
|
|
}
|
|
|
|
break;
|
|
case REORDER_BUFFER_CHANGE_MESSAGE:
|
|
{
|
|
Size prefix_size;
|
|
|
|
/* read prefix */
|
|
memcpy(&prefix_size, data, sizeof(Size));
|
|
data += sizeof(Size);
|
|
change->data.msg.prefix = MemoryContextAlloc(rb->context,
|
|
prefix_size);
|
|
memcpy(change->data.msg.prefix, data, prefix_size);
|
|
Assert(change->data.msg.prefix[prefix_size - 1] == '\0');
|
|
data += prefix_size;
|
|
|
|
/* read the message */
|
|
memcpy(&change->data.msg.message_size, data, sizeof(Size));
|
|
data += sizeof(Size);
|
|
change->data.msg.message = MemoryContextAlloc(rb->context,
|
|
change->data.msg.message_size);
|
|
memcpy(change->data.msg.message, data,
|
|
change->data.msg.message_size);
|
|
data += change->data.msg.message_size;
|
|
|
|
break;
|
|
}
|
|
case REORDER_BUFFER_CHANGE_INTERNAL_SNAPSHOT:
|
|
{
|
|
Snapshot oldsnap;
|
|
Snapshot newsnap;
|
|
Size size;
|
|
|
|
oldsnap = (Snapshot) data;
|
|
|
|
size = sizeof(SnapshotData) +
|
|
sizeof(TransactionId) * oldsnap->xcnt +
|
|
sizeof(TransactionId) * (oldsnap->subxcnt + 0);
|
|
|
|
change->data.snapshot = MemoryContextAllocZero(rb->context, size);
|
|
|
|
newsnap = change->data.snapshot;
|
|
|
|
memcpy(newsnap, data, size);
|
|
newsnap->xip = (TransactionId *)
|
|
(((char *) newsnap) + sizeof(SnapshotData));
|
|
newsnap->subxip = newsnap->xip + newsnap->xcnt;
|
|
newsnap->copied = true;
|
|
break;
|
|
}
|
|
/* the base struct contains all the data, easy peasy */
|
|
case REORDER_BUFFER_CHANGE_TRUNCATE:
|
|
{
|
|
Oid *relids;
|
|
|
|
relids = ReorderBufferGetRelids(rb,
|
|
change->data.truncate.nrelids);
|
|
memcpy(relids, data, change->data.truncate.nrelids * sizeof(Oid));
|
|
change->data.truncate.relids = relids;
|
|
|
|
break;
|
|
}
|
|
case REORDER_BUFFER_CHANGE_INTERNAL_SPEC_CONFIRM:
|
|
case REORDER_BUFFER_CHANGE_INTERNAL_COMMAND_ID:
|
|
case REORDER_BUFFER_CHANGE_INTERNAL_TUPLECID:
|
|
break;
|
|
}
|
|
|
|
dlist_push_tail(&txn->changes, &change->node);
|
|
txn->nentries_mem++;
|
|
}
|
|
|
|
/*
|
|
* Remove all on-disk stored for the passed in transaction.
|
|
*/
|
|
static void
|
|
ReorderBufferRestoreCleanup(ReorderBuffer *rb, ReorderBufferTXN *txn)
|
|
{
|
|
XLogSegNo first;
|
|
XLogSegNo cur;
|
|
XLogSegNo last;
|
|
|
|
Assert(txn->first_lsn != InvalidXLogRecPtr);
|
|
Assert(txn->final_lsn != InvalidXLogRecPtr);
|
|
|
|
XLByteToSeg(txn->first_lsn, first, wal_segment_size);
|
|
XLByteToSeg(txn->final_lsn, last, wal_segment_size);
|
|
|
|
/* iterate over all possible filenames, and delete them */
|
|
for (cur = first; cur <= last; cur++)
|
|
{
|
|
char path[MAXPGPATH];
|
|
|
|
ReorderBufferSerializedPath(path, MyReplicationSlot, txn->xid, cur);
|
|
if (unlink(path) != 0 && errno != ENOENT)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not remove file \"%s\": %m", path)));
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Remove any leftover serialized reorder buffers from a slot directory after a
|
|
* prior crash or decoding session exit.
|
|
*/
|
|
static void
|
|
ReorderBufferCleanupSerializedTXNs(const char *slotname)
|
|
{
|
|
DIR *spill_dir;
|
|
struct dirent *spill_de;
|
|
struct stat statbuf;
|
|
char path[MAXPGPATH * 2 + 12];
|
|
|
|
sprintf(path, "pg_replslot/%s", slotname);
|
|
|
|
/* we're only handling directories here, skip if it's not ours */
|
|
if (lstat(path, &statbuf) == 0 && !S_ISDIR(statbuf.st_mode))
|
|
return;
|
|
|
|
spill_dir = AllocateDir(path);
|
|
while ((spill_de = ReadDirExtended(spill_dir, path, INFO)) != NULL)
|
|
{
|
|
/* only look at names that can be ours */
|
|
if (strncmp(spill_de->d_name, "xid", 3) == 0)
|
|
{
|
|
snprintf(path, sizeof(path),
|
|
"pg_replslot/%s/%s", slotname,
|
|
spill_de->d_name);
|
|
|
|
if (unlink(path) != 0)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not remove file \"%s\" during removal of pg_replslot/%s/xid*: %m",
|
|
path, slotname)));
|
|
}
|
|
}
|
|
FreeDir(spill_dir);
|
|
}
|
|
|
|
/*
|
|
* Given a replication slot, transaction ID and segment number, fill in the
|
|
* corresponding spill file into 'path', which is a caller-owned buffer of size
|
|
* at least MAXPGPATH.
|
|
*/
|
|
static void
|
|
ReorderBufferSerializedPath(char *path, ReplicationSlot *slot, TransactionId xid,
|
|
XLogSegNo segno)
|
|
{
|
|
XLogRecPtr recptr;
|
|
|
|
XLogSegNoOffsetToRecPtr(segno, 0, wal_segment_size, recptr);
|
|
|
|
snprintf(path, MAXPGPATH, "pg_replslot/%s/xid-%u-lsn-%X-%X.spill",
|
|
NameStr(MyReplicationSlot->data.name),
|
|
xid,
|
|
(uint32) (recptr >> 32), (uint32) recptr);
|
|
}
|
|
|
|
/*
|
|
* Delete all data spilled to disk after we've restarted/crashed. It will be
|
|
* recreated when the respective slots are reused.
|
|
*/
|
|
void
|
|
StartupReorderBuffer(void)
|
|
{
|
|
DIR *logical_dir;
|
|
struct dirent *logical_de;
|
|
|
|
logical_dir = AllocateDir("pg_replslot");
|
|
while ((logical_de = ReadDir(logical_dir, "pg_replslot")) != NULL)
|
|
{
|
|
if (strcmp(logical_de->d_name, ".") == 0 ||
|
|
strcmp(logical_de->d_name, "..") == 0)
|
|
continue;
|
|
|
|
/* if it cannot be a slot, skip the directory */
|
|
if (!ReplicationSlotValidateName(logical_de->d_name, DEBUG2))
|
|
continue;
|
|
|
|
/*
|
|
* ok, has to be a surviving logical slot, iterate and delete
|
|
* everything starting with xid-*
|
|
*/
|
|
ReorderBufferCleanupSerializedTXNs(logical_de->d_name);
|
|
}
|
|
FreeDir(logical_dir);
|
|
}
|
|
|
|
/* ---------------------------------------
|
|
* toast reassembly support
|
|
* ---------------------------------------
|
|
*/
|
|
|
|
/*
|
|
* Initialize per tuple toast reconstruction support.
|
|
*/
|
|
static void
|
|
ReorderBufferToastInitHash(ReorderBuffer *rb, ReorderBufferTXN *txn)
|
|
{
|
|
HASHCTL hash_ctl;
|
|
|
|
Assert(txn->toast_hash == NULL);
|
|
|
|
memset(&hash_ctl, 0, sizeof(hash_ctl));
|
|
hash_ctl.keysize = sizeof(Oid);
|
|
hash_ctl.entrysize = sizeof(ReorderBufferToastEnt);
|
|
hash_ctl.hcxt = rb->context;
|
|
txn->toast_hash = hash_create("ReorderBufferToastHash", 5, &hash_ctl,
|
|
HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
|
|
}
|
|
|
|
/*
|
|
* Per toast-chunk handling for toast reconstruction
|
|
*
|
|
* Appends a toast chunk so we can reconstruct it when the tuple "owning" the
|
|
* toasted Datum comes along.
|
|
*/
|
|
static void
|
|
ReorderBufferToastAppendChunk(ReorderBuffer *rb, ReorderBufferTXN *txn,
|
|
Relation relation, ReorderBufferChange *change)
|
|
{
|
|
ReorderBufferToastEnt *ent;
|
|
ReorderBufferTupleBuf *newtup;
|
|
bool found;
|
|
int32 chunksize;
|
|
bool isnull;
|
|
Pointer chunk;
|
|
TupleDesc desc = RelationGetDescr(relation);
|
|
Oid chunk_id;
|
|
int32 chunk_seq;
|
|
|
|
if (txn->toast_hash == NULL)
|
|
ReorderBufferToastInitHash(rb, txn);
|
|
|
|
Assert(IsToastRelation(relation));
|
|
|
|
newtup = change->data.tp.newtuple;
|
|
chunk_id = DatumGetObjectId(fastgetattr(&newtup->tuple, 1, desc, &isnull));
|
|
Assert(!isnull);
|
|
chunk_seq = DatumGetInt32(fastgetattr(&newtup->tuple, 2, desc, &isnull));
|
|
Assert(!isnull);
|
|
|
|
ent = (ReorderBufferToastEnt *)
|
|
hash_search(txn->toast_hash,
|
|
(void *) &chunk_id,
|
|
HASH_ENTER,
|
|
&found);
|
|
|
|
if (!found)
|
|
{
|
|
Assert(ent->chunk_id == chunk_id);
|
|
ent->num_chunks = 0;
|
|
ent->last_chunk_seq = 0;
|
|
ent->size = 0;
|
|
ent->reconstructed = NULL;
|
|
dlist_init(&ent->chunks);
|
|
|
|
if (chunk_seq != 0)
|
|
elog(ERROR, "got sequence entry %d for toast chunk %u instead of seq 0",
|
|
chunk_seq, chunk_id);
|
|
}
|
|
else if (found && chunk_seq != ent->last_chunk_seq + 1)
|
|
elog(ERROR, "got sequence entry %d for toast chunk %u instead of seq %d",
|
|
chunk_seq, chunk_id, ent->last_chunk_seq + 1);
|
|
|
|
chunk = DatumGetPointer(fastgetattr(&newtup->tuple, 3, desc, &isnull));
|
|
Assert(!isnull);
|
|
|
|
/* calculate size so we can allocate the right size at once later */
|
|
if (!VARATT_IS_EXTENDED(chunk))
|
|
chunksize = VARSIZE(chunk) - VARHDRSZ;
|
|
else if (VARATT_IS_SHORT(chunk))
|
|
/* could happen due to heap_form_tuple doing its thing */
|
|
chunksize = VARSIZE_SHORT(chunk) - VARHDRSZ_SHORT;
|
|
else
|
|
elog(ERROR, "unexpected type of toast chunk");
|
|
|
|
ent->size += chunksize;
|
|
ent->last_chunk_seq = chunk_seq;
|
|
ent->num_chunks++;
|
|
dlist_push_tail(&ent->chunks, &change->node);
|
|
}
|
|
|
|
/*
|
|
* Rejigger change->newtuple to point to in-memory toast tuples instead to
|
|
* on-disk toast tuples that may not longer exist (think DROP TABLE or VACUUM).
|
|
*
|
|
* We cannot replace unchanged toast tuples though, so those will still point
|
|
* to on-disk toast data.
|
|
*/
|
|
static void
|
|
ReorderBufferToastReplace(ReorderBuffer *rb, ReorderBufferTXN *txn,
|
|
Relation relation, ReorderBufferChange *change)
|
|
{
|
|
TupleDesc desc;
|
|
int natt;
|
|
Datum *attrs;
|
|
bool *isnull;
|
|
bool *free;
|
|
HeapTuple tmphtup;
|
|
Relation toast_rel;
|
|
TupleDesc toast_desc;
|
|
MemoryContext oldcontext;
|
|
ReorderBufferTupleBuf *newtup;
|
|
|
|
/* no toast tuples changed */
|
|
if (txn->toast_hash == NULL)
|
|
return;
|
|
|
|
oldcontext = MemoryContextSwitchTo(rb->context);
|
|
|
|
/* we should only have toast tuples in an INSERT or UPDATE */
|
|
Assert(change->data.tp.newtuple);
|
|
|
|
desc = RelationGetDescr(relation);
|
|
|
|
toast_rel = RelationIdGetRelation(relation->rd_rel->reltoastrelid);
|
|
toast_desc = RelationGetDescr(toast_rel);
|
|
|
|
/* should we allocate from stack instead? */
|
|
attrs = palloc0(sizeof(Datum) * desc->natts);
|
|
isnull = palloc0(sizeof(bool) * desc->natts);
|
|
free = palloc0(sizeof(bool) * desc->natts);
|
|
|
|
newtup = change->data.tp.newtuple;
|
|
|
|
heap_deform_tuple(&newtup->tuple, desc, attrs, isnull);
|
|
|
|
for (natt = 0; natt < desc->natts; natt++)
|
|
{
|
|
Form_pg_attribute attr = TupleDescAttr(desc, natt);
|
|
ReorderBufferToastEnt *ent;
|
|
struct varlena *varlena;
|
|
|
|
/* va_rawsize is the size of the original datum -- including header */
|
|
struct varatt_external toast_pointer;
|
|
struct varatt_indirect redirect_pointer;
|
|
struct varlena *new_datum = NULL;
|
|
struct varlena *reconstructed;
|
|
dlist_iter it;
|
|
Size data_done = 0;
|
|
|
|
/* system columns aren't toasted */
|
|
if (attr->attnum < 0)
|
|
continue;
|
|
|
|
if (attr->attisdropped)
|
|
continue;
|
|
|
|
/* not a varlena datatype */
|
|
if (attr->attlen != -1)
|
|
continue;
|
|
|
|
/* no data */
|
|
if (isnull[natt])
|
|
continue;
|
|
|
|
/* ok, we know we have a toast datum */
|
|
varlena = (struct varlena *) DatumGetPointer(attrs[natt]);
|
|
|
|
/* no need to do anything if the tuple isn't external */
|
|
if (!VARATT_IS_EXTERNAL(varlena))
|
|
continue;
|
|
|
|
VARATT_EXTERNAL_GET_POINTER(toast_pointer, varlena);
|
|
|
|
/*
|
|
* Check whether the toast tuple changed, replace if so.
|
|
*/
|
|
ent = (ReorderBufferToastEnt *)
|
|
hash_search(txn->toast_hash,
|
|
(void *) &toast_pointer.va_valueid,
|
|
HASH_FIND,
|
|
NULL);
|
|
if (ent == NULL)
|
|
continue;
|
|
|
|
new_datum =
|
|
(struct varlena *) palloc0(INDIRECT_POINTER_SIZE);
|
|
|
|
free[natt] = true;
|
|
|
|
reconstructed = palloc0(toast_pointer.va_rawsize);
|
|
|
|
ent->reconstructed = reconstructed;
|
|
|
|
/* stitch toast tuple back together from its parts */
|
|
dlist_foreach(it, &ent->chunks)
|
|
{
|
|
bool isnull;
|
|
ReorderBufferChange *cchange;
|
|
ReorderBufferTupleBuf *ctup;
|
|
Pointer chunk;
|
|
|
|
cchange = dlist_container(ReorderBufferChange, node, it.cur);
|
|
ctup = cchange->data.tp.newtuple;
|
|
chunk = DatumGetPointer(
|
|
fastgetattr(&ctup->tuple, 3, toast_desc, &isnull));
|
|
|
|
Assert(!isnull);
|
|
Assert(!VARATT_IS_EXTERNAL(chunk));
|
|
Assert(!VARATT_IS_SHORT(chunk));
|
|
|
|
memcpy(VARDATA(reconstructed) + data_done,
|
|
VARDATA(chunk),
|
|
VARSIZE(chunk) - VARHDRSZ);
|
|
data_done += VARSIZE(chunk) - VARHDRSZ;
|
|
}
|
|
Assert(data_done == toast_pointer.va_extsize);
|
|
|
|
/* make sure its marked as compressed or not */
|
|
if (VARATT_EXTERNAL_IS_COMPRESSED(toast_pointer))
|
|
SET_VARSIZE_COMPRESSED(reconstructed, data_done + VARHDRSZ);
|
|
else
|
|
SET_VARSIZE(reconstructed, data_done + VARHDRSZ);
|
|
|
|
memset(&redirect_pointer, 0, sizeof(redirect_pointer));
|
|
redirect_pointer.pointer = reconstructed;
|
|
|
|
SET_VARTAG_EXTERNAL(new_datum, VARTAG_INDIRECT);
|
|
memcpy(VARDATA_EXTERNAL(new_datum), &redirect_pointer,
|
|
sizeof(redirect_pointer));
|
|
|
|
attrs[natt] = PointerGetDatum(new_datum);
|
|
}
|
|
|
|
/*
|
|
* Build tuple in separate memory & copy tuple back into the tuplebuf
|
|
* passed to the output plugin. We can't directly heap_fill_tuple() into
|
|
* the tuplebuf because attrs[] will point back into the current content.
|
|
*/
|
|
tmphtup = heap_form_tuple(desc, attrs, isnull);
|
|
Assert(newtup->tuple.t_len <= MaxHeapTupleSize);
|
|
Assert(ReorderBufferTupleBufData(newtup) == newtup->tuple.t_data);
|
|
|
|
memcpy(newtup->tuple.t_data, tmphtup->t_data, tmphtup->t_len);
|
|
newtup->tuple.t_len = tmphtup->t_len;
|
|
|
|
/*
|
|
* free resources we won't further need, more persistent stuff will be
|
|
* free'd in ReorderBufferToastReset().
|
|
*/
|
|
RelationClose(toast_rel);
|
|
pfree(tmphtup);
|
|
for (natt = 0; natt < desc->natts; natt++)
|
|
{
|
|
if (free[natt])
|
|
pfree(DatumGetPointer(attrs[natt]));
|
|
}
|
|
pfree(attrs);
|
|
pfree(free);
|
|
pfree(isnull);
|
|
|
|
MemoryContextSwitchTo(oldcontext);
|
|
}
|
|
|
|
/*
|
|
* Free all resources allocated for toast reconstruction.
|
|
*/
|
|
static void
|
|
ReorderBufferToastReset(ReorderBuffer *rb, ReorderBufferTXN *txn)
|
|
{
|
|
HASH_SEQ_STATUS hstat;
|
|
ReorderBufferToastEnt *ent;
|
|
|
|
if (txn->toast_hash == NULL)
|
|
return;
|
|
|
|
/* sequentially walk over the hash and free everything */
|
|
hash_seq_init(&hstat, txn->toast_hash);
|
|
while ((ent = (ReorderBufferToastEnt *) hash_seq_search(&hstat)) != NULL)
|
|
{
|
|
dlist_mutable_iter it;
|
|
|
|
if (ent->reconstructed != NULL)
|
|
pfree(ent->reconstructed);
|
|
|
|
dlist_foreach_modify(it, &ent->chunks)
|
|
{
|
|
ReorderBufferChange *change =
|
|
dlist_container(ReorderBufferChange, node, it.cur);
|
|
|
|
dlist_delete(&change->node);
|
|
ReorderBufferReturnChange(rb, change);
|
|
}
|
|
}
|
|
|
|
hash_destroy(txn->toast_hash);
|
|
txn->toast_hash = NULL;
|
|
}
|
|
|
|
|
|
/* ---------------------------------------
|
|
* Visibility support for logical decoding
|
|
*
|
|
*
|
|
* Lookup actual cmin/cmax values when using decoding snapshot. We can't
|
|
* always rely on stored cmin/cmax values because of two scenarios:
|
|
*
|
|
* * A tuple got changed multiple times during a single transaction and thus
|
|
* has got a combocid. Combocid's are only valid for the duration of a
|
|
* single transaction.
|
|
* * A tuple with a cmin but no cmax (and thus no combocid) got
|
|
* deleted/updated in another transaction than the one which created it
|
|
* which we are looking at right now. As only one of cmin, cmax or combocid
|
|
* is actually stored in the heap we don't have access to the value we
|
|
* need anymore.
|
|
*
|
|
* To resolve those problems we have a per-transaction hash of (cmin,
|
|
* cmax) tuples keyed by (relfilenode, ctid) which contains the actual
|
|
* (cmin, cmax) values. That also takes care of combocids by simply
|
|
* not caring about them at all. As we have the real cmin/cmax values
|
|
* combocids aren't interesting.
|
|
*
|
|
* As we only care about catalog tuples here the overhead of this
|
|
* hashtable should be acceptable.
|
|
*
|
|
* Heap rewrites complicate this a bit, check rewriteheap.c for
|
|
* details.
|
|
* -------------------------------------------------------------------------
|
|
*/
|
|
|
|
/* struct for qsort()ing mapping files by lsn somewhat efficiently */
|
|
typedef struct RewriteMappingFile
|
|
{
|
|
XLogRecPtr lsn;
|
|
char fname[MAXPGPATH];
|
|
} RewriteMappingFile;
|
|
|
|
#if NOT_USED
|
|
static void
|
|
DisplayMapping(HTAB *tuplecid_data)
|
|
{
|
|
HASH_SEQ_STATUS hstat;
|
|
ReorderBufferTupleCidEnt *ent;
|
|
|
|
hash_seq_init(&hstat, tuplecid_data);
|
|
while ((ent = (ReorderBufferTupleCidEnt *) hash_seq_search(&hstat)) != NULL)
|
|
{
|
|
elog(DEBUG3, "mapping: node: %u/%u/%u tid: %u/%u cmin: %u, cmax: %u",
|
|
ent->key.relnode.dbNode,
|
|
ent->key.relnode.spcNode,
|
|
ent->key.relnode.relNode,
|
|
ItemPointerGetBlockNumber(&ent->key.tid),
|
|
ItemPointerGetOffsetNumber(&ent->key.tid),
|
|
ent->cmin,
|
|
ent->cmax
|
|
);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Apply a single mapping file to tuplecid_data.
|
|
*
|
|
* The mapping file has to have been verified to be a) committed b) for our
|
|
* transaction c) applied in LSN order.
|
|
*/
|
|
static void
|
|
ApplyLogicalMappingFile(HTAB *tuplecid_data, Oid relid, const char *fname)
|
|
{
|
|
char path[MAXPGPATH];
|
|
int fd;
|
|
int readBytes;
|
|
LogicalRewriteMappingData map;
|
|
|
|
sprintf(path, "pg_logical/mappings/%s", fname);
|
|
fd = OpenTransientFile(path, O_RDONLY | PG_BINARY);
|
|
if (fd < 0)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open file \"%s\": %m", path)));
|
|
|
|
while (true)
|
|
{
|
|
ReorderBufferTupleCidKey key;
|
|
ReorderBufferTupleCidEnt *ent;
|
|
ReorderBufferTupleCidEnt *new_ent;
|
|
bool found;
|
|
|
|
/* be careful about padding */
|
|
memset(&key, 0, sizeof(ReorderBufferTupleCidKey));
|
|
|
|
/* read all mappings till the end of the file */
|
|
pgstat_report_wait_start(WAIT_EVENT_REORDER_LOGICAL_MAPPING_READ);
|
|
readBytes = read(fd, &map, sizeof(LogicalRewriteMappingData));
|
|
pgstat_report_wait_end();
|
|
|
|
if (readBytes < 0)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read file \"%s\": %m",
|
|
path)));
|
|
else if (readBytes == 0) /* EOF */
|
|
break;
|
|
else if (readBytes != sizeof(LogicalRewriteMappingData))
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read from file \"%s\": read %d instead of %d bytes",
|
|
path, readBytes,
|
|
(int32) sizeof(LogicalRewriteMappingData))));
|
|
|
|
key.relnode = map.old_node;
|
|
ItemPointerCopy(&map.old_tid,
|
|
&key.tid);
|
|
|
|
|
|
ent = (ReorderBufferTupleCidEnt *)
|
|
hash_search(tuplecid_data,
|
|
(void *) &key,
|
|
HASH_FIND,
|
|
NULL);
|
|
|
|
/* no existing mapping, no need to update */
|
|
if (!ent)
|
|
continue;
|
|
|
|
key.relnode = map.new_node;
|
|
ItemPointerCopy(&map.new_tid,
|
|
&key.tid);
|
|
|
|
new_ent = (ReorderBufferTupleCidEnt *)
|
|
hash_search(tuplecid_data,
|
|
(void *) &key,
|
|
HASH_ENTER,
|
|
&found);
|
|
|
|
if (found)
|
|
{
|
|
/*
|
|
* Make sure the existing mapping makes sense. We sometime update
|
|
* old records that did not yet have a cmax (e.g. pg_class' own
|
|
* entry while rewriting it) during rewrites, so allow that.
|
|
*/
|
|
Assert(ent->cmin == InvalidCommandId || ent->cmin == new_ent->cmin);
|
|
Assert(ent->cmax == InvalidCommandId || ent->cmax == new_ent->cmax);
|
|
}
|
|
else
|
|
{
|
|
/* update mapping */
|
|
new_ent->cmin = ent->cmin;
|
|
new_ent->cmax = ent->cmax;
|
|
new_ent->combocid = ent->combocid;
|
|
}
|
|
}
|
|
|
|
if (CloseTransientFile(fd))
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not close file \"%s\": %m", path)));
|
|
}
|
|
|
|
|
|
/*
|
|
* Check whether the TransactionOid 'xid' is in the pre-sorted array 'xip'.
|
|
*/
|
|
static bool
|
|
TransactionIdInArray(TransactionId xid, TransactionId *xip, Size num)
|
|
{
|
|
return bsearch(&xid, xip, num,
|
|
sizeof(TransactionId), xidComparator) != NULL;
|
|
}
|
|
|
|
/*
|
|
* qsort() comparator for sorting RewriteMappingFiles in LSN order.
|
|
*/
|
|
static int
|
|
file_sort_by_lsn(const void *a_p, const void *b_p)
|
|
{
|
|
RewriteMappingFile *a = *(RewriteMappingFile **) a_p;
|
|
RewriteMappingFile *b = *(RewriteMappingFile **) b_p;
|
|
|
|
if (a->lsn < b->lsn)
|
|
return -1;
|
|
else if (a->lsn > b->lsn)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Apply any existing logical remapping files if there are any targeted at our
|
|
* transaction for relid.
|
|
*/
|
|
static void
|
|
UpdateLogicalMappings(HTAB *tuplecid_data, Oid relid, Snapshot snapshot)
|
|
{
|
|
DIR *mapping_dir;
|
|
struct dirent *mapping_de;
|
|
List *files = NIL;
|
|
ListCell *file;
|
|
RewriteMappingFile **files_a;
|
|
size_t off;
|
|
Oid dboid = IsSharedRelation(relid) ? InvalidOid : MyDatabaseId;
|
|
|
|
mapping_dir = AllocateDir("pg_logical/mappings");
|
|
while ((mapping_de = ReadDir(mapping_dir, "pg_logical/mappings")) != NULL)
|
|
{
|
|
Oid f_dboid;
|
|
Oid f_relid;
|
|
TransactionId f_mapped_xid;
|
|
TransactionId f_create_xid;
|
|
XLogRecPtr f_lsn;
|
|
uint32 f_hi,
|
|
f_lo;
|
|
RewriteMappingFile *f;
|
|
|
|
if (strcmp(mapping_de->d_name, ".") == 0 ||
|
|
strcmp(mapping_de->d_name, "..") == 0)
|
|
continue;
|
|
|
|
/* Ignore files that aren't ours */
|
|
if (strncmp(mapping_de->d_name, "map-", 4) != 0)
|
|
continue;
|
|
|
|
if (sscanf(mapping_de->d_name, LOGICAL_REWRITE_FORMAT,
|
|
&f_dboid, &f_relid, &f_hi, &f_lo,
|
|
&f_mapped_xid, &f_create_xid) != 6)
|
|
elog(ERROR, "could not parse filename \"%s\"", mapping_de->d_name);
|
|
|
|
f_lsn = ((uint64) f_hi) << 32 | f_lo;
|
|
|
|
/* mapping for another database */
|
|
if (f_dboid != dboid)
|
|
continue;
|
|
|
|
/* mapping for another relation */
|
|
if (f_relid != relid)
|
|
continue;
|
|
|
|
/* did the creating transaction abort? */
|
|
if (!TransactionIdDidCommit(f_create_xid))
|
|
continue;
|
|
|
|
/* not for our transaction */
|
|
if (!TransactionIdInArray(f_mapped_xid, snapshot->subxip, snapshot->subxcnt))
|
|
continue;
|
|
|
|
/* ok, relevant, queue for apply */
|
|
f = palloc(sizeof(RewriteMappingFile));
|
|
f->lsn = f_lsn;
|
|
strcpy(f->fname, mapping_de->d_name);
|
|
files = lappend(files, f);
|
|
}
|
|
FreeDir(mapping_dir);
|
|
|
|
/* build array we can easily sort */
|
|
files_a = palloc(list_length(files) * sizeof(RewriteMappingFile *));
|
|
off = 0;
|
|
foreach(file, files)
|
|
{
|
|
files_a[off++] = lfirst(file);
|
|
}
|
|
|
|
/* sort files so we apply them in LSN order */
|
|
qsort(files_a, list_length(files), sizeof(RewriteMappingFile *),
|
|
file_sort_by_lsn);
|
|
|
|
for (off = 0; off < list_length(files); off++)
|
|
{
|
|
RewriteMappingFile *f = files_a[off];
|
|
|
|
elog(DEBUG1, "applying mapping: \"%s\" in %u", f->fname,
|
|
snapshot->subxip[0]);
|
|
ApplyLogicalMappingFile(tuplecid_data, relid, f->fname);
|
|
pfree(f);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Lookup cmin/cmax of a tuple, during logical decoding where we can't rely on
|
|
* combocids.
|
|
*/
|
|
bool
|
|
ResolveCminCmaxDuringDecoding(HTAB *tuplecid_data,
|
|
Snapshot snapshot,
|
|
HeapTuple htup, Buffer buffer,
|
|
CommandId *cmin, CommandId *cmax)
|
|
{
|
|
ReorderBufferTupleCidKey key;
|
|
ReorderBufferTupleCidEnt *ent;
|
|
ForkNumber forkno;
|
|
BlockNumber blockno;
|
|
bool updated_mapping = false;
|
|
|
|
/* be careful about padding */
|
|
memset(&key, 0, sizeof(key));
|
|
|
|
Assert(!BufferIsLocal(buffer));
|
|
|
|
/*
|
|
* get relfilenode from the buffer, no convenient way to access it other
|
|
* than that.
|
|
*/
|
|
BufferGetTag(buffer, &key.relnode, &forkno, &blockno);
|
|
|
|
/* tuples can only be in the main fork */
|
|
Assert(forkno == MAIN_FORKNUM);
|
|
Assert(blockno == ItemPointerGetBlockNumber(&htup->t_self));
|
|
|
|
ItemPointerCopy(&htup->t_self,
|
|
&key.tid);
|
|
|
|
restart:
|
|
ent = (ReorderBufferTupleCidEnt *)
|
|
hash_search(tuplecid_data,
|
|
(void *) &key,
|
|
HASH_FIND,
|
|
NULL);
|
|
|
|
/*
|
|
* failed to find a mapping, check whether the table was rewritten and
|
|
* apply mapping if so, but only do that once - there can be no new
|
|
* mappings while we are in here since we have to hold a lock on the
|
|
* relation.
|
|
*/
|
|
if (ent == NULL && !updated_mapping)
|
|
{
|
|
UpdateLogicalMappings(tuplecid_data, htup->t_tableOid, snapshot);
|
|
/* now check but don't update for a mapping again */
|
|
updated_mapping = true;
|
|
goto restart;
|
|
}
|
|
else if (ent == NULL)
|
|
return false;
|
|
|
|
if (cmin)
|
|
*cmin = ent->cmin;
|
|
if (cmax)
|
|
*cmax = ent->cmax;
|
|
return true;
|
|
}
|