decode.c File Reference

#include "postgres.h"
#include "access/heapam_xlog.h"
#include "access/transam.h"
#include "access/xact.h"
#include "access/xlog_internal.h"
#include "access/xlogreader.h"
#include "access/xlogrecord.h"
#include "catalog/pg_control.h"
#include "replication/decode.h"
#include "replication/logical.h"
#include "replication/message.h"
#include "replication/reorderbuffer.h"
#include "replication/snapbuild.h"
#include "storage/standbydefs.h"

Include dependency graph for decode.c:

Go to the source code of this file.

Functions
static void	DecodeInsert (LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
static void	DecodeUpdate (LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
static void	DecodeDelete (LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
static void	DecodeTruncate (LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
static void	DecodeMultiInsert (LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
static void	DecodeSpecConfirm (LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
static void	DecodeCommit (LogicalDecodingContext *ctx, XLogRecordBuffer *buf, xl_xact_parsed_commit *parsed, TransactionId xid, bool two_phase)
static void	DecodeAbort (LogicalDecodingContext *ctx, XLogRecordBuffer *buf, xl_xact_parsed_abort *parsed, TransactionId xid, bool two_phase)
static void	DecodePrepare (LogicalDecodingContext *ctx, XLogRecordBuffer *buf, xl_xact_parsed_prepare *parsed)
static void	DecodeXLogTuple (char *data, Size len, HeapTuple tuple)
static bool	FilterPrepare (LogicalDecodingContext *ctx, TransactionId xid, const char *gid)
static bool	DecodeTXNNeedSkip (LogicalDecodingContext *ctx, XLogRecordBuffer *buf, Oid txn_dbid, ReplOriginId origin_id)
void	LogicalDecodingProcessRecord (LogicalDecodingContext *ctx, XLogReaderState *record)
void	xlog_decode (LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
void	xact_decode (LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
void	standby_decode (LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
void	heap2_decode (LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
void	heap_decode (LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
static bool	FilterByOrigin (LogicalDecodingContext *ctx, ReplOriginId origin_id)
void	logicalmsg_decode (LogicalDecodingContext *ctx, XLogRecordBuffer *buf)

Function Documentation

DecodeAbort()

static void DecodeAbort ( LogicalDecodingContext *  ctx, XLogRecordBuffer *  buf, xl_xact_parsed_abort *  parsed, TransactionId  xid, bool  two_phase  )

static

Definition at line 832 of file decode.c.

{
    int         i;
    XLogRecPtr  origin_lsn = InvalidXLogRecPtr;
    TimestampTz abort_time = parsed->xact_time;
    ReplOriginId origin_id = XLogRecGetOrigin(buf->record);
    bool        skip_xact;
 
    if (parsed->xinfo & XACT_XINFO_HAS_ORIGIN)
    {
        origin_lsn = parsed->origin_lsn;
        abort_time = parsed->origin_timestamp;
    }
 
    /*
     * Check whether we need to process this transaction. See
     * DecodeTXNNeedSkip for the reasons why we sometimes want to skip the
     * transaction.
     */
    skip_xact = DecodeTXNNeedSkip(ctx, buf, parsed->dbId, origin_id);
 
    /*
     * Send the final rollback record for a prepared transaction unless we
     * need to skip it. For non-two-phase xacts, simply forget the xact.
     */
    if (two_phase && !skip_xact)
    {
        ReorderBufferFinishPrepared(ctx->reorder, xid, buf->origptr, buf->endptr,
                                    InvalidXLogRecPtr,
                                    abort_time, origin_id, origin_lsn,
                                    parsed->twophase_gid, false);
    }
    else
    {
        for (i = 0; i < parsed->nsubxacts; i++)
        {
            ReorderBufferAbort(ctx->reorder, parsed->subxacts[i],
                               buf->record->EndRecPtr, abort_time);
        }
 
        ReorderBufferAbort(ctx->reorder, xid, buf->record->EndRecPtr,
                           abort_time);
    }
 
    /* update the decoding stats */
    UpdateDecodingStats(ctx);
}

References buf, DecodeTXNNeedSkip(), fb(), i, InvalidXLogRecPtr, LogicalDecodingContext::reorder, ReorderBufferAbort(), ReorderBufferFinishPrepared(), two_phase, UpdateDecodingStats(), XACT_XINFO_HAS_ORIGIN, and XLogRecGetOrigin.

Referenced by xact_decode().

DecodeCommit()

static void DecodeCommit ( LogicalDecodingContext *  ctx, XLogRecordBuffer *  buf, xl_xact_parsed_commit *  parsed, TransactionId  xid, bool  two_phase  )

static

Definition at line 661 of file decode.c.

{
    XLogRecPtr  origin_lsn = InvalidXLogRecPtr;
    TimestampTz commit_time = parsed->xact_time;
    ReplOriginId origin_id = XLogRecGetOrigin(buf->record);
    int         i;
 
    if (parsed->xinfo & XACT_XINFO_HAS_ORIGIN)
    {
        origin_lsn = parsed->origin_lsn;
        commit_time = parsed->origin_timestamp;
    }
 
    SnapBuildCommitTxn(ctx->snapshot_builder, buf->origptr, xid,
                       parsed->nsubxacts, parsed->subxacts,
                       parsed->xinfo);
 
    /* ----
     * Check whether we are interested in this specific transaction, and tell
     * the reorderbuffer to forget the content of the (sub-)transactions
     * if not.
     *
     * We can't just use ReorderBufferAbort() here, because we need to execute
     * the transaction's invalidations.  This currently won't be needed if
     * we're just skipping over the transaction because currently we only do
     * so during startup, to get to the first transaction the client needs. As
     * we have reset the catalog caches before starting to read WAL, and we
     * haven't yet touched any catalogs, there can't be anything to invalidate.
     * But if we're "forgetting" this commit because it happened in another
     * database, the invalidations might be important, because they could be
     * for shared catalogs and we might have loaded data into the relevant
     * syscaches.
     * ---
     */
    if (DecodeTXNNeedSkip(ctx, buf, parsed->dbId, origin_id))
    {
        for (i = 0; i < parsed->nsubxacts; i++)
        {
            ReorderBufferForget(ctx->reorder, parsed->subxacts[i], buf->origptr);
        }
        ReorderBufferForget(ctx->reorder, xid, buf->origptr);
 
        return;
    }
 
    /* tell the reorderbuffer about the surviving subtransactions */
    for (i = 0; i < parsed->nsubxacts; i++)
    {
        ReorderBufferCommitChild(ctx->reorder, xid, parsed->subxacts[i],
                                 buf->origptr, buf->endptr);
    }
 
    /*
     * Send the final commit record if the transaction data is already
     * decoded, otherwise, process the entire transaction.
     */
    if (two_phase)
    {
        ReorderBufferFinishPrepared(ctx->reorder, xid, buf->origptr, buf->endptr,
                                    SnapBuildGetTwoPhaseAt(ctx->snapshot_builder),
                                    commit_time, origin_id, origin_lsn,
                                    parsed->twophase_gid, true);
    }
    else
    {
        ReorderBufferCommit(ctx->reorder, xid, buf->origptr, buf->endptr,
                            commit_time, origin_id, origin_lsn);
    }
 
    /*
     * Update the decoding stats at transaction prepare/commit/abort.
     * Additionally we send the stats when we spill or stream the changes to
     * avoid losing them in case the decoding is interrupted. It is not clear
     * that sending more or less frequently than this would be better.
     */
    UpdateDecodingStats(ctx);
}

References buf, DecodeTXNNeedSkip(), fb(), i, InvalidXLogRecPtr, LogicalDecodingContext::reorder, ReorderBufferCommit(), ReorderBufferCommitChild(), ReorderBufferFinishPrepared(), ReorderBufferForget(), SnapBuildCommitTxn(), SnapBuildGetTwoPhaseAt(), LogicalDecodingContext::snapshot_builder, two_phase, UpdateDecodingStats(), XACT_XINFO_HAS_ORIGIN, and XLogRecGetOrigin.

Referenced by xact_decode().

DecodeDelete()

static void DecodeDelete ( LogicalDecodingContext *  ctx, XLogRecordBuffer *  buf  )

static

Definition at line 1014 of file decode.c.

{
    XLogReaderState *r = buf->record;
    xl_heap_delete *xlrec;
    ReorderBufferChange *change;
    RelFileLocator target_locator;
 
    xlrec = (xl_heap_delete *) XLogRecGetData(r);
 
    /* only interested in our database */
    XLogRecGetBlockTag(r, 0, &target_locator, NULL, NULL);
    if (target_locator.dbOid != ctx->slot->data.database)
        return;
 
    /* output plugin doesn't look for this origin, no need to queue */
    if (FilterByOrigin(ctx, XLogRecGetOrigin(r)))
        return;
 
    change = ReorderBufferAllocChange(ctx->reorder);
 
    if (xlrec->flags & XLH_DELETE_IS_SUPER)
        change->action = REORDER_BUFFER_CHANGE_INTERNAL_SPEC_ABORT;
    else
        change->action = REORDER_BUFFER_CHANGE_DELETE;
 
    change->origin_id = XLogRecGetOrigin(r);
 
    memcpy(&change->data.tp.rlocator, &target_locator, sizeof(RelFileLocator));
 
    /* old primary key stored */
    if (xlrec->flags & XLH_DELETE_CONTAINS_OLD)
    {
        Size        datalen = XLogRecGetDataLen(r) - SizeOfHeapDelete;
        Size        tuplelen = datalen - SizeOfHeapHeader;
 
        Assert(XLogRecGetDataLen(r) > (SizeOfHeapDelete + SizeOfHeapHeader));
 
        change->data.tp.oldtuple =
            ReorderBufferAllocTupleBuf(ctx->reorder, tuplelen);
 
        DecodeXLogTuple((char *) xlrec + SizeOfHeapDelete,
                        datalen, change->data.tp.oldtuple);
    }
 
    change->data.tp.clear_toast_afterwards = true;
 
    ReorderBufferQueueChange(ctx->reorder, XLogRecGetXid(r), buf->origptr,
                             change, false);
}

References ReorderBufferChange::action, Assert, buf, ReorderBufferChange::clear_toast_afterwards, ReorderBufferChange::data, ReplicationSlot::data, ReplicationSlotPersistentData::database, RelFileLocator::dbOid, DecodeXLogTuple(), fb(), FilterByOrigin(), ReorderBufferChange::oldtuple, ReorderBufferChange::origin_id, XLogReaderState::record, LogicalDecodingContext::reorder, REORDER_BUFFER_CHANGE_DELETE, REORDER_BUFFER_CHANGE_INTERNAL_SPEC_ABORT, ReorderBufferAllocChange(), ReorderBufferAllocTupleBuf(), ReorderBufferQueueChange(), ReorderBufferChange::rlocator, SizeOfHeapDelete, SizeOfHeapHeader, LogicalDecodingContext::slot, ReorderBufferChange::tp, XLH_DELETE_CONTAINS_OLD, XLH_DELETE_IS_SUPER, XLogRecGetBlockTag(), XLogRecGetData, XLogRecGetDataLen, XLogRecGetOrigin, and XLogRecGetXid.

Referenced by heap_decode().

DecodeInsert()

static void DecodeInsert ( LogicalDecodingContext *  ctx, XLogRecordBuffer *  buf  )

static

Definition at line 888 of file decode.c.

{
    Size        datalen;
    char       *tupledata;
    Size        tuplelen;
    XLogReaderState *r = buf->record;
    xl_heap_insert *xlrec;
    ReorderBufferChange *change;
    RelFileLocator target_locator;
 
    xlrec = (xl_heap_insert *) XLogRecGetData(r);
 
    /*
     * Ignore insert records without new tuples (this does happen when
     * raw_heap_insert marks the TOAST record as HEAP_INSERT_NO_LOGICAL).
     */
    if (!(xlrec->flags & XLH_INSERT_CONTAINS_NEW_TUPLE))
        return;
 
    /* only interested in our database */
    XLogRecGetBlockTag(r, 0, &target_locator, NULL, NULL);
    if (target_locator.dbOid != ctx->slot->data.database)
        return;
 
    /* output plugin doesn't look for this origin, no need to queue */
    if (FilterByOrigin(ctx, XLogRecGetOrigin(r)))
        return;
 
    change = ReorderBufferAllocChange(ctx->reorder);
    if (!(xlrec->flags & XLH_INSERT_IS_SPECULATIVE))
        change->action = REORDER_BUFFER_CHANGE_INSERT;
    else
        change->action = REORDER_BUFFER_CHANGE_INTERNAL_SPEC_INSERT;
    change->origin_id = XLogRecGetOrigin(r);
 
    memcpy(&change->data.tp.rlocator, &target_locator, sizeof(RelFileLocator));
 
    tupledata = XLogRecGetBlockData(r, 0, &datalen);
    tuplelen = datalen - SizeOfHeapHeader;
 
    change->data.tp.newtuple =
        ReorderBufferAllocTupleBuf(ctx->reorder, tuplelen);
 
    DecodeXLogTuple(tupledata, datalen, change->data.tp.newtuple);
 
    change->data.tp.clear_toast_afterwards = true;
 
    ReorderBufferQueueChange(ctx->reorder, XLogRecGetXid(r), buf->origptr,
                             change,
                             xlrec->flags & XLH_INSERT_ON_TOAST_RELATION);
}

References ReorderBufferChange::action, buf, ReorderBufferChange::clear_toast_afterwards, ReorderBufferChange::data, ReplicationSlot::data, ReplicationSlotPersistentData::database, RelFileLocator::dbOid, DecodeXLogTuple(), fb(), FilterByOrigin(), ReorderBufferChange::newtuple, ReorderBufferChange::origin_id, XLogReaderState::record, LogicalDecodingContext::reorder, REORDER_BUFFER_CHANGE_INSERT, REORDER_BUFFER_CHANGE_INTERNAL_SPEC_INSERT, ReorderBufferAllocChange(), ReorderBufferAllocTupleBuf(), ReorderBufferQueueChange(), ReorderBufferChange::rlocator, SizeOfHeapHeader, LogicalDecodingContext::slot, ReorderBufferChange::tp, XLH_INSERT_CONTAINS_NEW_TUPLE, XLH_INSERT_IS_SPECULATIVE, XLH_INSERT_ON_TOAST_RELATION, XLogRecGetBlockData(), XLogRecGetBlockTag(), XLogRecGetData, XLogRecGetOrigin, and XLogRecGetXid.

Referenced by heap_decode().

DecodeMultiInsert()

static void DecodeMultiInsert ( LogicalDecodingContext *  ctx, XLogRecordBuffer *  buf  )

static

Definition at line 1106 of file decode.c.

{
    XLogReaderState *r = buf->record;
    xl_heap_multi_insert *xlrec;
    int         i;
    char       *data;
    char       *tupledata;
    Size        tuplelen;
    RelFileLocator rlocator;
 
    xlrec = (xl_heap_multi_insert *) XLogRecGetData(r);
 
    /*
     * Ignore insert records without new tuples.  This happens when a
     * multi_insert is done on a catalog or on a non-persistent relation.
     */
    if (!(xlrec->flags & XLH_INSERT_CONTAINS_NEW_TUPLE))
        return;
 
    /* only interested in our database */
    XLogRecGetBlockTag(r, 0, &rlocator, NULL, NULL);
    if (rlocator.dbOid != ctx->slot->data.database)
        return;
 
    /* output plugin doesn't look for this origin, no need to queue */
    if (FilterByOrigin(ctx, XLogRecGetOrigin(r)))
        return;
 
    /*
     * We know that this multi_insert isn't for a catalog, so the block should
     * always have data even if a full-page write of it is taken.
     */
    tupledata = XLogRecGetBlockData(r, 0, &tuplelen);
    Assert(tupledata != NULL);
 
    data = tupledata;
    for (i = 0; i < xlrec->ntuples; i++)
    {
        ReorderBufferChange *change;
        xl_multi_insert_tuple *xlhdr;
        int         datalen;
        HeapTuple   tuple;
        HeapTupleHeader header;
 
        change = ReorderBufferAllocChange(ctx->reorder);
        change->action = REORDER_BUFFER_CHANGE_INSERT;
        change->origin_id = XLogRecGetOrigin(r);
 
        memcpy(&change->data.tp.rlocator, &rlocator, sizeof(RelFileLocator));
 
        xlhdr = (xl_multi_insert_tuple *) SHORTALIGN(data);
        data = ((char *) xlhdr) + SizeOfMultiInsertTuple;
        datalen = xlhdr->datalen;
 
        change->data.tp.newtuple =
            ReorderBufferAllocTupleBuf(ctx->reorder, datalen);
 
        tuple = change->data.tp.newtuple;
        header = tuple->t_data;
 
        /* not a disk based tuple */
        ItemPointerSetInvalid(&tuple->t_self);
 
        /*
         * We can only figure this out after reassembling the transactions.
         */
        tuple->t_tableOid = InvalidOid;
 
        tuple->t_len = datalen + SizeofHeapTupleHeader;
 
        memset(header, 0, SizeofHeapTupleHeader);
 
        memcpy((char *) tuple->t_data + SizeofHeapTupleHeader, data, datalen);
        header->t_infomask = xlhdr->t_infomask;
        header->t_infomask2 = xlhdr->t_infomask2;
        header->t_hoff = xlhdr->t_hoff;
 
        /*
         * Reset toast reassembly state only after the last row in the last
         * xl_multi_insert_tuple record emitted by one heap_multi_insert()
         * call.
         */
        if (xlrec->flags & XLH_INSERT_LAST_IN_MULTI &&
            (i + 1) == xlrec->ntuples)
            change->data.tp.clear_toast_afterwards = true;
        else
            change->data.tp.clear_toast_afterwards = false;
 
        ReorderBufferQueueChange(ctx->reorder, XLogRecGetXid(r),
                                 buf->origptr, change, false);
 
        /* move to the next xl_multi_insert_tuple entry */
        data += datalen;
    }
    Assert(data == tupledata + tuplelen);
}

References ReorderBufferChange::action, Assert, buf, ReorderBufferChange::clear_toast_afterwards, ReorderBufferChange::data, ReplicationSlot::data, data, ReplicationSlotPersistentData::database, RelFileLocator::dbOid, fb(), FilterByOrigin(), i, InvalidOid, ItemPointerSetInvalid(), ReorderBufferChange::newtuple, ReorderBufferChange::origin_id, XLogReaderState::record, LogicalDecodingContext::reorder, REORDER_BUFFER_CHANGE_INSERT, ReorderBufferAllocChange(), ReorderBufferAllocTupleBuf(), ReorderBufferQueueChange(), ReorderBufferChange::rlocator, SHORTALIGN, SizeofHeapTupleHeader, SizeOfMultiInsertTuple, LogicalDecodingContext::slot, HeapTupleData::t_data, HeapTupleHeaderData::t_hoff, HeapTupleHeaderData::t_infomask, HeapTupleHeaderData::t_infomask2, HeapTupleData::t_len, HeapTupleData::t_self, HeapTupleData::t_tableOid, ReorderBufferChange::tp, XLH_INSERT_CONTAINS_NEW_TUPLE, XLH_INSERT_LAST_IN_MULTI, XLogRecGetBlockData(), XLogRecGetBlockTag(), XLogRecGetData, XLogRecGetOrigin, and XLogRecGetXid.

Referenced by heap2_decode().

DecodePrepare()

static void DecodePrepare ( LogicalDecodingContext *  ctx, XLogRecordBuffer *  buf, xl_xact_parsed_prepare *  parsed  )

static

Definition at line 757 of file decode.c.

{
    SnapBuild  *builder = ctx->snapshot_builder;
    XLogRecPtr  origin_lsn = parsed->origin_lsn;
    TimestampTz prepare_time = parsed->xact_time;
    ReplOriginId origin_id = XLogRecGetOrigin(buf->record);
    int         i;
    TransactionId xid = parsed->twophase_xid;
 
    if (parsed->origin_timestamp != 0)
        prepare_time = parsed->origin_timestamp;
 
    /*
     * Remember the prepare info for a txn so that it can be used later in
     * commit prepared if required. See ReorderBufferFinishPrepared.
     */
    if (!ReorderBufferRememberPrepareInfo(ctx->reorder, xid, buf->origptr,
                                          buf->endptr, prepare_time, origin_id,
                                          origin_lsn))
        return;
 
    /* We can't start streaming unless a consistent state is reached. */
    if (SnapBuildCurrentState(builder) < SNAPBUILD_CONSISTENT)
    {
        ReorderBufferSkipPrepare(ctx->reorder, xid);
        return;
    }
 
    /*
     * Check whether we need to process this transaction. See
     * DecodeTXNNeedSkip for the reasons why we sometimes want to skip the
     * transaction.
     *
     * We can't call ReorderBufferForget as we did in DecodeCommit as the txn
     * hasn't yet been committed, removing this txn before a commit might
     * result in the computation of an incorrect restart_lsn. See
     * SnapBuildProcessRunningXacts. But we need to process cache
     * invalidations if there are any for the reasons mentioned in
     * DecodeCommit.
     */
    if (DecodeTXNNeedSkip(ctx, buf, parsed->dbId, origin_id))
    {
        ReorderBufferSkipPrepare(ctx->reorder, xid);
        ReorderBufferInvalidate(ctx->reorder, xid, buf->origptr);
        return;
    }
 
    /* Tell the reorderbuffer about the surviving subtransactions. */
    for (i = 0; i < parsed->nsubxacts; i++)
    {
        ReorderBufferCommitChild(ctx->reorder, xid, parsed->subxacts[i],
                                 buf->origptr, buf->endptr);
    }
 
    /* replay actions of all transaction + subtransactions in order */
    ReorderBufferPrepare(ctx->reorder, xid, parsed->twophase_gid);
 
    /*
     * Update the decoding stats at transaction prepare/commit/abort.
     * Additionally we send the stats when we spill or stream the changes to
     * avoid losing them in case the decoding is interrupted. It is not clear
     * that sending more or less frequently than this would be better.
     */
    UpdateDecodingStats(ctx);
}

References buf, DecodeTXNNeedSkip(), fb(), i, LogicalDecodingContext::reorder, ReorderBufferCommitChild(), ReorderBufferInvalidate(), ReorderBufferPrepare(), ReorderBufferRememberPrepareInfo(), ReorderBufferSkipPrepare(), SNAPBUILD_CONSISTENT, SnapBuildCurrentState(), LogicalDecodingContext::snapshot_builder, UpdateDecodingStats(), and XLogRecGetOrigin.

Referenced by xact_decode().

DecodeSpecConfirm()

static void DecodeSpecConfirm ( LogicalDecodingContext *  ctx, XLogRecordBuffer *  buf  )

static

Definition at line 1210 of file decode.c.

{
    XLogReaderState *r = buf->record;
    ReorderBufferChange *change;
    RelFileLocator target_locator;
 
    /* only interested in our database */
    XLogRecGetBlockTag(r, 0, &target_locator, NULL, NULL);
    if (target_locator.dbOid != ctx->slot->data.database)
        return;
 
    /* output plugin doesn't look for this origin, no need to queue */
    if (FilterByOrigin(ctx, XLogRecGetOrigin(r)))
        return;
 
    change = ReorderBufferAllocChange(ctx->reorder);
    change->action = REORDER_BUFFER_CHANGE_INTERNAL_SPEC_CONFIRM;
    change->origin_id = XLogRecGetOrigin(r);
 
    memcpy(&change->data.tp.rlocator, &target_locator, sizeof(RelFileLocator));
 
    change->data.tp.clear_toast_afterwards = true;
 
    ReorderBufferQueueChange(ctx->reorder, XLogRecGetXid(r), buf->origptr,
                             change, false);
}

References ReorderBufferChange::action, buf, ReorderBufferChange::clear_toast_afterwards, ReorderBufferChange::data, ReplicationSlot::data, ReplicationSlotPersistentData::database, RelFileLocator::dbOid, fb(), FilterByOrigin(), ReorderBufferChange::origin_id, XLogReaderState::record, LogicalDecodingContext::reorder, REORDER_BUFFER_CHANGE_INTERNAL_SPEC_CONFIRM, ReorderBufferAllocChange(), ReorderBufferQueueChange(), ReorderBufferChange::rlocator, LogicalDecodingContext::slot, ReorderBufferChange::tp, XLogRecGetBlockTag(), XLogRecGetOrigin, and XLogRecGetXid.

Referenced by heap_decode().

DecodeTruncate()

static void DecodeTruncate ( LogicalDecodingContext *  ctx, XLogRecordBuffer *  buf  )

static

Definition at line 1068 of file decode.c.

{
    XLogReaderState *r = buf->record;
    xl_heap_truncate *xlrec;
    ReorderBufferChange *change;
 
    xlrec = (xl_heap_truncate *) XLogRecGetData(r);
 
    /* only interested in our database */
    if (xlrec->dbId != ctx->slot->data.database)
        return;
 
    /* output plugin doesn't look for this origin, no need to queue */
    if (FilterByOrigin(ctx, XLogRecGetOrigin(r)))
        return;
 
    change = ReorderBufferAllocChange(ctx->reorder);
    change->action = REORDER_BUFFER_CHANGE_TRUNCATE;
    change->origin_id = XLogRecGetOrigin(r);
    if (xlrec->flags & XLH_TRUNCATE_CASCADE)
        change->data.truncate.cascade = true;
    if (xlrec->flags & XLH_TRUNCATE_RESTART_SEQS)
        change->data.truncate.restart_seqs = true;
    change->data.truncate.nrelids = xlrec->nrelids;
    change->data.truncate.relids = ReorderBufferAllocRelids(ctx->reorder,
                                                            xlrec->nrelids);
    memcpy(change->data.truncate.relids, xlrec->relids,
           xlrec->nrelids * sizeof(Oid));
    ReorderBufferQueueChange(ctx->reorder, XLogRecGetXid(r),
                             buf->origptr, change, false);
}

References ReorderBufferChange::action, buf, ReorderBufferChange::cascade, ReorderBufferChange::data, ReplicationSlot::data, ReplicationSlotPersistentData::database, fb(), FilterByOrigin(), ReorderBufferChange::nrelids, ReorderBufferChange::origin_id, XLogReaderState::record, ReorderBufferChange::relids, LogicalDecodingContext::reorder, REORDER_BUFFER_CHANGE_TRUNCATE, ReorderBufferAllocChange(), ReorderBufferAllocRelids(), ReorderBufferQueueChange(), ReorderBufferChange::restart_seqs, LogicalDecodingContext::slot, ReorderBufferChange::truncate, XLH_TRUNCATE_CASCADE, XLH_TRUNCATE_RESTART_SEQS, XLogRecGetData, XLogRecGetOrigin, and XLogRecGetXid.

Referenced by heap_decode().

DecodeTXNNeedSkip()

static bool DecodeTXNNeedSkip ( LogicalDecodingContext *  ctx, XLogRecordBuffer *  buf, Oid  txn_dbid, ReplOriginId  origin_id  )

static

Definition at line 1290 of file decode.c.

{
    if (SnapBuildXactNeedsSkip(ctx->snapshot_builder, buf->origptr) ||
        (txn_dbid != InvalidOid && txn_dbid != ctx->slot->data.database) ||
        FilterByOrigin(ctx, origin_id))
        return true;
 
    /*
     * We also skip decoding in fast_forward mode. In passing set the
     * processing_required flag to indicate that if it were not for
     * fast_forward mode, processing would have been required.
     */
    if (ctx->fast_forward)
    {
        ctx->processing_required = true;
        return true;
    }
 
    return false;
}

References buf, ReplicationSlot::data, ReplicationSlotPersistentData::database, LogicalDecodingContext::fast_forward, fb(), FilterByOrigin(), InvalidOid, LogicalDecodingContext::processing_required, LogicalDecodingContext::slot, SnapBuildXactNeedsSkip(), and LogicalDecodingContext::snapshot_builder.

Referenced by DecodeAbort(), DecodeCommit(), and DecodePrepare().

DecodeUpdate()

static void DecodeUpdate ( LogicalDecodingContext *  ctx, XLogRecordBuffer *  buf  )

static

Definition at line 947 of file decode.c.

{
    XLogReaderState *r = buf->record;
    xl_heap_update *xlrec;
    ReorderBufferChange *change;
    char       *data;
    RelFileLocator target_locator;
 
    xlrec = (xl_heap_update *) XLogRecGetData(r);
 
    /* only interested in our database */
    XLogRecGetBlockTag(r, 0, &target_locator, NULL, NULL);
    if (target_locator.dbOid != ctx->slot->data.database)
        return;
 
    /* output plugin doesn't look for this origin, no need to queue */
    if (FilterByOrigin(ctx, XLogRecGetOrigin(r)))
        return;
 
    change = ReorderBufferAllocChange(ctx->reorder);
    change->action = REORDER_BUFFER_CHANGE_UPDATE;
    change->origin_id = XLogRecGetOrigin(r);
    memcpy(&change->data.tp.rlocator, &target_locator, sizeof(RelFileLocator));
 
    if (xlrec->flags & XLH_UPDATE_CONTAINS_NEW_TUPLE)
    {
        Size        datalen;
        Size        tuplelen;
 
        data = XLogRecGetBlockData(r, 0, &datalen);
 
        tuplelen = datalen - SizeOfHeapHeader;
 
        change->data.tp.newtuple =
            ReorderBufferAllocTupleBuf(ctx->reorder, tuplelen);
 
        DecodeXLogTuple(data, datalen, change->data.tp.newtuple);
    }
 
    if (xlrec->flags & XLH_UPDATE_CONTAINS_OLD)
    {
        Size        datalen;
        Size        tuplelen;
 
        /* caution, remaining data in record is not aligned */
        data = XLogRecGetData(r) + SizeOfHeapUpdate;
        datalen = XLogRecGetDataLen(r) - SizeOfHeapUpdate;
        tuplelen = datalen - SizeOfHeapHeader;
 
        change->data.tp.oldtuple =
            ReorderBufferAllocTupleBuf(ctx->reorder, tuplelen);
 
        DecodeXLogTuple(data, datalen, change->data.tp.oldtuple);
    }
 
    change->data.tp.clear_toast_afterwards = true;
 
    ReorderBufferQueueChange(ctx->reorder, XLogRecGetXid(r), buf->origptr,
                             change, false);
}

References ReorderBufferChange::action, buf, ReorderBufferChange::clear_toast_afterwards, ReorderBufferChange::data, ReplicationSlot::data, data, ReplicationSlotPersistentData::database, RelFileLocator::dbOid, DecodeXLogTuple(), fb(), FilterByOrigin(), ReorderBufferChange::newtuple, ReorderBufferChange::oldtuple, ReorderBufferChange::origin_id, XLogReaderState::record, LogicalDecodingContext::reorder, REORDER_BUFFER_CHANGE_UPDATE, ReorderBufferAllocChange(), ReorderBufferAllocTupleBuf(), ReorderBufferQueueChange(), ReorderBufferChange::rlocator, SizeOfHeapHeader, SizeOfHeapUpdate, LogicalDecodingContext::slot, ReorderBufferChange::tp, XLH_UPDATE_CONTAINS_NEW_TUPLE, XLH_UPDATE_CONTAINS_OLD, XLogRecGetBlockData(), XLogRecGetBlockTag(), XLogRecGetData, XLogRecGetDataLen, XLogRecGetOrigin, and XLogRecGetXid.

Referenced by heap_decode().

DecodeXLogTuple()

static void DecodeXLogTuple ( char *  data, Size  len, HeapTuple  tuple  )

static

Definition at line 1246 of file decode.c.

{
    xl_heap_header xlhdr;
    int         datalen = len - SizeOfHeapHeader;
    HeapTupleHeader header;
 
    Assert(datalen >= 0);
 
    tuple->t_len = datalen + SizeofHeapTupleHeader;
    header = tuple->t_data;
 
    /* not a disk based tuple */
    ItemPointerSetInvalid(&tuple->t_self);
 
    /* we can only figure this out after reassembling the transactions */
    tuple->t_tableOid = InvalidOid;
 
    /* data is not stored aligned, copy to aligned storage */
    memcpy(&xlhdr, data, SizeOfHeapHeader);
 
    memset(header, 0, SizeofHeapTupleHeader);
 
    memcpy(((char *) tuple->t_data) + SizeofHeapTupleHeader,
           data + SizeOfHeapHeader,
           datalen);
 
    header->t_infomask = xlhdr.t_infomask;
    header->t_infomask2 = xlhdr.t_infomask2;
    header->t_hoff = xlhdr.t_hoff;
}

References Assert, data, fb(), InvalidOid, ItemPointerSetInvalid(), len, SizeOfHeapHeader, SizeofHeapTupleHeader, HeapTupleData::t_data, HeapTupleHeaderData::t_hoff, HeapTupleHeaderData::t_infomask, HeapTupleHeaderData::t_infomask2, HeapTupleData::t_len, HeapTupleData::t_self, and HeapTupleData::t_tableOid.

Referenced by DecodeDelete(), DecodeInsert(), and DecodeUpdate().

FilterByOrigin()

static bool FilterByOrigin ( LogicalDecodingContext *  ctx, ReplOriginId  origin_id  )

inlinestatic

Definition at line 568 of file decode.c.

{
    if (ctx->callbacks.filter_by_origin_cb == NULL)
        return false;
 
    return filter_by_origin_cb_wrapper(ctx, origin_id);
}

References LogicalDecodingContext::callbacks, fb(), OutputPluginCallbacks::filter_by_origin_cb, and filter_by_origin_cb_wrapper().

Referenced by DecodeDelete(), DecodeInsert(), DecodeMultiInsert(), DecodeSpecConfirm(), DecodeTruncate(), DecodeTXNNeedSkip(), DecodeUpdate(), and logicalmsg_decode().

FilterPrepare()

static bool FilterPrepare ( LogicalDecodingContext *  ctx, TransactionId  xid, const char *  gid  )

inlinestatic

Definition at line 545 of file decode.c.

{
    /*
     * Skip if decoding of two-phase transactions at PREPARE time is not
     * enabled. In that case, all two-phase transactions are considered
     * filtered out and will be applied as regular transactions at COMMIT
     * PREPARED.
     */
    if (!ctx->twophase)
        return true;
 
    /*
     * The filter_prepare callback is optional. When not supplied, all
     * prepared transactions should go through.
     */
    if (ctx->callbacks.filter_prepare_cb == NULL)
        return false;
 
    return filter_prepare_cb_wrapper(ctx, xid, gid);
}

References LogicalDecodingContext::callbacks, fb(), OutputPluginCallbacks::filter_prepare_cb, filter_prepare_cb_wrapper(), and LogicalDecodingContext::twophase.

Referenced by xact_decode().

heap2_decode()

void heap2_decode	(	LogicalDecodingContext *	ctx,
		XLogRecordBuffer *	buf
	)

Definition at line 400 of file decode.c.

{
    uint8       info = XLogRecGetInfo(buf->record) & XLOG_HEAP_OPMASK;
    TransactionId xid = XLogRecGetXid(buf->record);
    SnapBuild  *builder = ctx->snapshot_builder;
 
    ReorderBufferProcessXid(ctx->reorder, xid, buf->origptr);
 
    /*
     * If we don't have snapshot or we are just fast-forwarding, there is no
     * point in decoding data changes. However, it's crucial to build the base
     * snapshot during fast-forward mode (as is done in
     * SnapBuildProcessChange()) because we require the snapshot's xmin when
     * determining the candidate catalog_xmin for the replication slot. See
     * SnapBuildProcessRunningXacts().
     */
    if (SnapBuildCurrentState(builder) < SNAPBUILD_FULL_SNAPSHOT)
        return;
 
    switch (info)
    {
        case XLOG_HEAP2_MULTI_INSERT:
            if (SnapBuildProcessChange(builder, xid, buf->origptr) &&
                !ctx->fast_forward)
                DecodeMultiInsert(ctx, buf);
            break;
        case XLOG_HEAP2_NEW_CID:
            if (!ctx->fast_forward)
            {
                xl_heap_new_cid *xlrec;
 
                xlrec = (xl_heap_new_cid *) XLogRecGetData(buf->record);
                SnapBuildProcessNewCid(builder, xid, buf->origptr, xlrec);
            }
            break;
        case XLOG_HEAP2_REWRITE:
 
            /*
             * Although these records only exist to serve the needs of logical
             * decoding, all the work happens as part of crash or archive
             * recovery, so we don't need to do anything here.
             */
            break;
 
            /*
             * Everything else here is just low level physical stuff we're not
             * interested in.
             */
        case XLOG_HEAP2_PRUNE_ON_ACCESS:
        case XLOG_HEAP2_PRUNE_VACUUM_SCAN:
        case XLOG_HEAP2_PRUNE_VACUUM_CLEANUP:
        case XLOG_HEAP2_VISIBLE:
        case XLOG_HEAP2_LOCK_UPDATED:
            break;
        default:
            elog(ERROR, "unexpected RM_HEAP2_ID record type: %u", info);
    }
}

References buf, DecodeMultiInsert(), elog, ERROR, LogicalDecodingContext::fast_forward, fb(), LogicalDecodingContext::reorder, ReorderBufferProcessXid(), SNAPBUILD_FULL_SNAPSHOT, SnapBuildCurrentState(), SnapBuildProcessChange(), SnapBuildProcessNewCid(), LogicalDecodingContext::snapshot_builder, XLOG_HEAP2_LOCK_UPDATED, XLOG_HEAP2_MULTI_INSERT, XLOG_HEAP2_NEW_CID, XLOG_HEAP2_PRUNE_ON_ACCESS, XLOG_HEAP2_PRUNE_VACUUM_CLEANUP, XLOG_HEAP2_PRUNE_VACUUM_SCAN, XLOG_HEAP2_REWRITE, XLOG_HEAP2_VISIBLE, XLOG_HEAP_OPMASK, XLogRecGetData, XLogRecGetInfo, and XLogRecGetXid.

heap_decode()

void heap_decode	(	LogicalDecodingContext *	ctx,
		XLogRecordBuffer *	buf
	)

Definition at line 463 of file decode.c.

{
    uint8       info = XLogRecGetInfo(buf->record) & XLOG_HEAP_OPMASK;
    TransactionId xid = XLogRecGetXid(buf->record);
    SnapBuild  *builder = ctx->snapshot_builder;
 
    ReorderBufferProcessXid(ctx->reorder, xid, buf->origptr);
 
    /*
     * If we don't have snapshot or we are just fast-forwarding, there is no
     * point in decoding data changes. However, it's crucial to build the base
     * snapshot during fast-forward mode (as is done in
     * SnapBuildProcessChange()) because we require the snapshot's xmin when
     * determining the candidate catalog_xmin for the replication slot. See
     * SnapBuildProcessRunningXacts().
     */
    if (SnapBuildCurrentState(builder) < SNAPBUILD_FULL_SNAPSHOT)
        return;
 
    switch (info)
    {
        case XLOG_HEAP_INSERT:
            if (SnapBuildProcessChange(builder, xid, buf->origptr) &&
                !ctx->fast_forward)
                DecodeInsert(ctx, buf);
            break;
 
            /*
             * Treat HOT update as normal updates. There is no useful
             * information in the fact that we could make it a HOT update
             * locally and the WAL layout is compatible.
             */
        case XLOG_HEAP_HOT_UPDATE:
        case XLOG_HEAP_UPDATE:
            if (SnapBuildProcessChange(builder, xid, buf->origptr) &&
                !ctx->fast_forward)
                DecodeUpdate(ctx, buf);
            break;
 
        case XLOG_HEAP_DELETE:
            if (SnapBuildProcessChange(builder, xid, buf->origptr) &&
                !ctx->fast_forward)
                DecodeDelete(ctx, buf);
            break;
 
        case XLOG_HEAP_TRUNCATE:
            if (SnapBuildProcessChange(builder, xid, buf->origptr) &&
                !ctx->fast_forward)
                DecodeTruncate(ctx, buf);
            break;
 
        case XLOG_HEAP_INPLACE:
 
            /*
             * Inplace updates are only ever performed on catalog tuples and
             * can, per definition, not change tuple visibility.  Since we
             * also don't decode catalog tuples, we're not interested in the
             * record's contents.
             */
            break;
 
        case XLOG_HEAP_CONFIRM:
            if (SnapBuildProcessChange(builder, xid, buf->origptr) &&
                !ctx->fast_forward)
                DecodeSpecConfirm(ctx, buf);
            break;
 
        case XLOG_HEAP_LOCK:
            /* we don't care about row level locks for now */
            break;
 
        default:
            elog(ERROR, "unexpected RM_HEAP_ID record type: %u", info);
            break;
    }
}

References buf, DecodeDelete(), DecodeInsert(), DecodeSpecConfirm(), DecodeTruncate(), DecodeUpdate(), elog, ERROR, LogicalDecodingContext::fast_forward, LogicalDecodingContext::reorder, ReorderBufferProcessXid(), SNAPBUILD_FULL_SNAPSHOT, SnapBuildCurrentState(), SnapBuildProcessChange(), LogicalDecodingContext::snapshot_builder, XLOG_HEAP_CONFIRM, XLOG_HEAP_DELETE, XLOG_HEAP_HOT_UPDATE, XLOG_HEAP_INPLACE, XLOG_HEAP_INSERT, XLOG_HEAP_LOCK, XLOG_HEAP_OPMASK, XLOG_HEAP_TRUNCATE, XLOG_HEAP_UPDATE, XLogRecGetInfo, and XLogRecGetXid.

LogicalDecodingProcessRecord()

void LogicalDecodingProcessRecord	(	LogicalDecodingContext *	ctx,
		XLogReaderState *	record
	)

Definition at line 88 of file decode.c.

{
    XLogRecordBuffer buf;
    TransactionId txid;
    RmgrData    rmgr;
 
    buf.origptr = ctx->reader->ReadRecPtr;
    buf.endptr = ctx->reader->EndRecPtr;
    buf.record = record;
 
    txid = XLogRecGetTopXid(record);
 
    /*
     * If the top-level xid is valid, we need to assign the subxact to the
     * top-level xact. We need to do this for all records, hence we do it
     * before the switch.
     */
    if (TransactionIdIsValid(txid))
    {
        ReorderBufferAssignChild(ctx->reorder,
                                 txid,
                                 XLogRecGetXid(record),
                                 buf.origptr);
    }
 
    rmgr = GetRmgr(XLogRecGetRmid(record));
 
    if (rmgr.rm_decode != NULL)
        rmgr.rm_decode(ctx, &buf);
    else
    {
        /* just deal with xid, and done */
        ReorderBufferProcessXid(ctx->reorder, XLogRecGetXid(record),
                                buf.origptr);
    }
}

References buf, XLogReaderState::EndRecPtr, fb(), GetRmgr(), LogicalDecodingContext::reader, XLogReaderState::ReadRecPtr, LogicalDecodingContext::reorder, ReorderBufferAssignChild(), ReorderBufferProcessXid(), TransactionIdIsValid, XLogRecGetRmid, XLogRecGetTopXid, and XLogRecGetXid.

Referenced by DecodingContextFindStartpoint(), LogicalReplicationSlotCheckPendingWal(), LogicalSlotAdvanceAndCheckSnapState(), pg_logical_slot_get_changes_guts(), and XLogSendLogical().

logicalmsg_decode()

void logicalmsg_decode	(	LogicalDecodingContext *	ctx,
		XLogRecordBuffer *	buf
	)

Definition at line 580 of file decode.c.

{
    SnapBuild  *builder = ctx->snapshot_builder;
    XLogReaderState *r = buf->record;
    TransactionId xid = XLogRecGetXid(r);
    uint8       info = XLogRecGetInfo(r) & ~XLR_INFO_MASK;
    ReplOriginId origin_id = XLogRecGetOrigin(r);
    Snapshot    snapshot = NULL;
    xl_logical_message *message;
 
    if (info != XLOG_LOGICAL_MESSAGE)
        elog(ERROR, "unexpected RM_LOGICALMSG_ID record type: %u", info);
 
    ReorderBufferProcessXid(ctx->reorder, XLogRecGetXid(r), buf->origptr);
 
    /* If we don't have snapshot, there is no point in decoding messages */
    if (SnapBuildCurrentState(builder) < SNAPBUILD_FULL_SNAPSHOT)
        return;
 
    message = (xl_logical_message *) XLogRecGetData(r);
 
    if (message->dbId != ctx->slot->data.database ||
        FilterByOrigin(ctx, origin_id))
        return;
 
    if (message->transactional &&
        !SnapBuildProcessChange(builder, xid, buf->origptr))
        return;
    else if (!message->transactional &&
             (SnapBuildCurrentState(builder) != SNAPBUILD_CONSISTENT ||
              SnapBuildXactNeedsSkip(builder, buf->origptr)))
        return;
 
    /*
     * We also skip decoding in fast_forward mode. This check must be last
     * because we don't want to set the processing_required flag unless we
     * have a decodable message.
     */
    if (ctx->fast_forward)
    {
        /*
         * We need to set processing_required flag to notify the message's
         * existence to the caller. Usually, the flag is set when either the
         * COMMIT or ABORT records are decoded, but this must be turned on
         * here because the non-transactional logical message is decoded
         * without waiting for these records.
         */
        if (!message->transactional)
            ctx->processing_required = true;
 
        return;
    }
 
    /*
     * If this is a non-transactional change, get the snapshot we're expected
     * to use. We only get here when the snapshot is consistent, and the
     * change is not meant to be skipped.
     *
     * For transactional changes we don't need a snapshot, we'll use the
     * regular snapshot maintained by ReorderBuffer. We just leave it NULL.
     */
    if (!message->transactional)
        snapshot = SnapBuildGetOrBuildSnapshot(builder);
 
    ReorderBufferQueueMessage(ctx->reorder, xid, snapshot, buf->endptr,
                              message->transactional,
                              message->message, /* first part of message is
                                                 * prefix */
                              message->message_size,
                              message->message + message->prefix_size);
}

References buf, ReplicationSlot::data, ReplicationSlotPersistentData::database, xl_logical_message::dbId, elog, ERROR, LogicalDecodingContext::fast_forward, fb(), FilterByOrigin(), xl_logical_message::message, xl_logical_message::message_size, xl_logical_message::prefix_size, LogicalDecodingContext::processing_required, XLogReaderState::record, LogicalDecodingContext::reorder, ReorderBufferProcessXid(), ReorderBufferQueueMessage(), LogicalDecodingContext::slot, SNAPBUILD_CONSISTENT, SNAPBUILD_FULL_SNAPSHOT, SnapBuildCurrentState(), SnapBuildGetOrBuildSnapshot(), SnapBuildProcessChange(), SnapBuildXactNeedsSkip(), LogicalDecodingContext::snapshot_builder, xl_logical_message::transactional, XLOG_LOGICAL_MESSAGE, XLogRecGetData, XLogRecGetInfo, XLogRecGetOrigin, and XLogRecGetXid.

standby_decode()

void standby_decode	(	LogicalDecodingContext *	ctx,
		XLogRecordBuffer *	buf
	)

Definition at line 354 of file decode.c.

{
    SnapBuild  *builder = ctx->snapshot_builder;
    XLogReaderState *r = buf->record;
    uint8       info = XLogRecGetInfo(r) & ~XLR_INFO_MASK;
 
    ReorderBufferProcessXid(ctx->reorder, XLogRecGetXid(r), buf->origptr);
 
    switch (info)
    {
        case XLOG_RUNNING_XACTS:
            {
                xl_running_xacts *running = (xl_running_xacts *) XLogRecGetData(r);
 
                SnapBuildProcessRunningXacts(builder, buf->origptr, running);
 
                /*
                 * Abort all transactions that we keep track of, that are
                 * older than the record's oldestRunningXid. This is the most
                 * convenient spot for doing so since, in contrast to shutdown
                 * or end-of-recovery checkpoints, we have information about
                 * all running transactions which includes prepared ones,
                 * while shutdown checkpoints just know that no non-prepared
                 * transactions are in progress.
                 */
                ReorderBufferAbortOld(ctx->reorder, running->oldestRunningXid);
            }
            break;
        case XLOG_STANDBY_LOCK:
            break;
        case XLOG_INVALIDATIONS:
 
            /*
             * We are processing the invalidations at the command level via
             * XLOG_XACT_INVALIDATIONS.  So we don't need to do anything here.
             */
            break;
        default:
            elog(ERROR, "unexpected RM_STANDBY_ID record type: %u", info);
    }
}

References buf, elog, ERROR, fb(), xl_running_xacts::oldestRunningXid, XLogReaderState::record, LogicalDecodingContext::reorder, ReorderBufferAbortOld(), ReorderBufferProcessXid(), SnapBuildProcessRunningXacts(), LogicalDecodingContext::snapshot_builder, XLOG_INVALIDATIONS, XLOG_RUNNING_XACTS, XLOG_STANDBY_LOCK, XLogRecGetData, XLogRecGetInfo, and XLogRecGetXid.

xact_decode()

void xact_decode	(	LogicalDecodingContext *	ctx,
		XLogRecordBuffer *	buf
	)

Definition at line 196 of file decode.c.

{
    SnapBuild  *builder = ctx->snapshot_builder;
    ReorderBuffer *reorder = ctx->reorder;
    XLogReaderState *r = buf->record;
    uint8       info = XLogRecGetInfo(r) & XLOG_XACT_OPMASK;
 
    /*
     * If the snapshot isn't yet fully built, we cannot decode anything, so
     * bail out.
     */
    if (SnapBuildCurrentState(builder) < SNAPBUILD_FULL_SNAPSHOT)
        return;
 
    switch (info)
    {
        case XLOG_XACT_COMMIT:
        case XLOG_XACT_COMMIT_PREPARED:
            {
                xl_xact_commit *xlrec;
                xl_xact_parsed_commit parsed;
                TransactionId xid;
                bool        two_phase = false;
 
                xlrec = (xl_xact_commit *) XLogRecGetData(r);
                ParseCommitRecord(XLogRecGetInfo(buf->record), xlrec, &parsed);
 
                if (!TransactionIdIsValid(parsed.twophase_xid))
                    xid = XLogRecGetXid(r);
                else
                    xid = parsed.twophase_xid;
 
                /*
                 * We would like to process the transaction in a two-phase
                 * manner iff output plugin supports two-phase commits and
                 * doesn't filter the transaction at prepare time.
                 */
                if (info == XLOG_XACT_COMMIT_PREPARED)
                    two_phase = !(FilterPrepare(ctx, xid,
                                                parsed.twophase_gid));
 
                DecodeCommit(ctx, buf, &parsed, xid, two_phase);
                break;
            }
        case XLOG_XACT_ABORT:
        case XLOG_XACT_ABORT_PREPARED:
            {
                xl_xact_abort *xlrec;
                xl_xact_parsed_abort parsed;
                TransactionId xid;
                bool        two_phase = false;
 
                xlrec = (xl_xact_abort *) XLogRecGetData(r);
                ParseAbortRecord(XLogRecGetInfo(buf->record), xlrec, &parsed);
 
                if (!TransactionIdIsValid(parsed.twophase_xid))
                    xid = XLogRecGetXid(r);
                else
                    xid = parsed.twophase_xid;
 
                /*
                 * We would like to process the transaction in a two-phase
                 * manner iff output plugin supports two-phase commits and
                 * doesn't filter the transaction at prepare time.
                 */
                if (info == XLOG_XACT_ABORT_PREPARED)
                    two_phase = !(FilterPrepare(ctx, xid,
                                                parsed.twophase_gid));
 
                DecodeAbort(ctx, buf, &parsed, xid, two_phase);
                break;
            }
        case XLOG_XACT_ASSIGNMENT:
 
            /*
             * We assign subxact to the toplevel xact while processing each
             * record if required.  So, we don't need to do anything here. See
             * LogicalDecodingProcessRecord.
             */
            break;
        case XLOG_XACT_INVALIDATIONS:
            {
                TransactionId xid;
                xl_xact_invals *invals;
 
                xid = XLogRecGetXid(r);
                invals = (xl_xact_invals *) XLogRecGetData(r);
 
                /*
                 * Execute the invalidations for xid-less transactions,
                 * otherwise, accumulate them so that they can be processed at
                 * the commit time.
                 */
                if (TransactionIdIsValid(xid))
                {
                    if (!ctx->fast_forward)
                        ReorderBufferAddInvalidations(reorder, xid,
                                                      buf->origptr,
                                                      invals->nmsgs,
                                                      invals->msgs);
                    ReorderBufferXidSetCatalogChanges(ctx->reorder, xid,
                                                      buf->origptr);
                }
                else if (!ctx->fast_forward)
                    ReorderBufferImmediateInvalidation(ctx->reorder,
                                                       invals->nmsgs,
                                                       invals->msgs);
 
                break;
            }
        case XLOG_XACT_PREPARE:
            {
                xl_xact_parsed_prepare parsed;
                xl_xact_prepare *xlrec;
 
                /* ok, parse it */
                xlrec = (xl_xact_prepare *) XLogRecGetData(r);
                ParsePrepareRecord(XLogRecGetInfo(buf->record),
                                   xlrec, &parsed);
 
                /*
                 * We would like to process the transaction in a two-phase
                 * manner iff output plugin supports two-phase commits and
                 * doesn't filter the transaction at prepare time.
                 */
                if (FilterPrepare(ctx, parsed.twophase_xid,
                                  parsed.twophase_gid))
                {
                    ReorderBufferProcessXid(reorder, parsed.twophase_xid,
                                            buf->origptr);
                    break;
                }
 
                /*
                 * Note that if the prepared transaction has locked [user]
                 * catalog tables exclusively then decoding prepare can block
                 * till the main transaction is committed because it needs to
                 * lock the catalog tables.
                 *
                 * XXX Now, this can even lead to a deadlock if the prepare
                 * transaction is waiting to get it logically replicated for
                 * distributed 2PC. This can be avoided by disallowing
                 * preparing transactions that have locked [user] catalog
                 * tables exclusively but as of now, we ask users not to do
                 * such an operation.
                 */
                DecodePrepare(ctx, buf, &parsed);
                break;
            }
        default:
            elog(ERROR, "unexpected RM_XACT_ID record type: %u", info);
    }
}

References buf, DecodeAbort(), DecodeCommit(), DecodePrepare(), elog, ERROR, LogicalDecodingContext::fast_forward, fb(), FilterPrepare(), ParseAbortRecord(), ParseCommitRecord(), ParsePrepareRecord(), XLogReaderState::record, LogicalDecodingContext::reorder, ReorderBufferAddInvalidations(), ReorderBufferImmediateInvalidation(), ReorderBufferProcessXid(), ReorderBufferXidSetCatalogChanges(), SNAPBUILD_FULL_SNAPSHOT, SnapBuildCurrentState(), LogicalDecodingContext::snapshot_builder, TransactionIdIsValid, two_phase, XLOG_XACT_ABORT, XLOG_XACT_ABORT_PREPARED, XLOG_XACT_ASSIGNMENT, XLOG_XACT_COMMIT, XLOG_XACT_COMMIT_PREPARED, XLOG_XACT_INVALIDATIONS, XLOG_XACT_OPMASK, XLOG_XACT_PREPARE, XLogRecGetData, XLogRecGetInfo, and XLogRecGetXid.

xlog_decode()

void xlog_decode	(	LogicalDecodingContext *	ctx,
		XLogRecordBuffer *	buf
	)

Definition at line 129 of file decode.c.

{
    SnapBuild  *builder = ctx->snapshot_builder;
    uint8       info = XLogRecGetInfo(buf->record) & ~XLR_INFO_MASK;
 
    ReorderBufferProcessXid(ctx->reorder, XLogRecGetXid(buf->record),
                            buf->origptr);
 
    switch (info)
    {
            /* this is also used in END_OF_RECOVERY checkpoints */
        case XLOG_CHECKPOINT_SHUTDOWN:
        case XLOG_END_OF_RECOVERY:
            SnapBuildSerializationPoint(builder, buf->origptr);
 
            break;
        case XLOG_CHECKPOINT_ONLINE:
 
            /*
             * a RUNNING_XACTS record will have been logged near to this, we
             * can restart from there.
             */
            break;
        case XLOG_LOGICAL_DECODING_STATUS_CHANGE:
            {
                bool        logical_decoding;
 
                memcpy(&logical_decoding, XLogRecGetData(buf->record), sizeof(bool));
 
                /*
                 * Error out as we should not decode this WAL record.
                 *
                 * Logical decoding is disabled, and existing logical slots on
                 * the standby are invalidated when this WAL record is
                 * replayed. No logical decoder can process this WAL record
                 * until replay completes, and by then the slots are already
                 * invalidated. Furthermore, no new logical slots can be
                 * created while logical decoding is disabled. This cannot
                 * occur even on primary either, since it will not restart
                 * with wal_level < replica if any logical slots exist.
                 */
                elog(ERROR, "unexpected logical decoding status change %d",
                     logical_decoding);
 
                break;
            }
        case XLOG_NOOP:
        case XLOG_NEXTOID:
        case XLOG_SWITCH:
        case XLOG_BACKUP_END:
        case XLOG_PARAMETER_CHANGE:
        case XLOG_RESTORE_POINT:
        case XLOG_FPW_CHANGE:
        case XLOG_FPI_FOR_HINT:
        case XLOG_FPI:
        case XLOG_OVERWRITE_CONTRECORD:
        case XLOG_CHECKPOINT_REDO:
            break;
        default:
            elog(ERROR, "unexpected RM_XLOG_ID record type: %u", info);
    }
}

References buf, elog, ERROR, fb(), LogicalDecodingContext::reorder, ReorderBufferProcessXid(), SnapBuildSerializationPoint(), LogicalDecodingContext::snapshot_builder, XLOG_BACKUP_END, XLOG_CHECKPOINT_ONLINE, XLOG_CHECKPOINT_REDO, XLOG_CHECKPOINT_SHUTDOWN, XLOG_END_OF_RECOVERY, XLOG_FPI, XLOG_FPI_FOR_HINT, XLOG_FPW_CHANGE, XLOG_LOGICAL_DECODING_STATUS_CHANGE, XLOG_NEXTOID, XLOG_NOOP, XLOG_OVERWRITE_CONTRECORD, XLOG_PARAMETER_CHANGE, XLOG_RESTORE_POINT, XLOG_SWITCH, XLogRecGetData, XLogRecGetInfo, and XLogRecGetXid.