xactdesc.c

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/*-------------------------------------------------------------------------
 *
 * xactdesc.c
 *    rmgr descriptor routines for access/transam/xact.c
 *
 * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *    src/backend/access/rmgrdesc/xactdesc.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"
 
#include "access/transam.h"
#include "access/xact.h"
#include "replication/origin.h"
#include "storage/sinval.h"
#include "storage/standbydefs.h"
#include "utils/timestamp.h"
 
/*
 * Parse the WAL format of an xact commit and abort records into an easier to
 * understand format.
 *
 * These routines are in xactdesc.c because they're accessed in backend (when
 * replaying WAL) and frontend (pg_waldump) code. This file is the only xact
 * specific one shared between both. They're complicated enough that
 * duplication would be bothersome.
 */
 
void
ParseCommitRecord(uint8 info, xl_xact_commit *xlrec, xl_xact_parsed_commit *parsed)
{
    char       *data = ((char *) xlrec) + MinSizeOfXactCommit;
 
    memset(parsed, 0, sizeof(*parsed));
 
    parsed->xinfo = 0;          /* default, if no XLOG_XACT_HAS_INFO is
                                 * present */
 
    parsed->xact_time = xlrec->xact_time;
 
    if (info & XLOG_XACT_HAS_INFO)
    {
        xl_xact_xinfo *xl_xinfo = (xl_xact_xinfo *) data;
 
        parsed->xinfo = xl_xinfo->xinfo;
 
        data += sizeof(xl_xact_xinfo);
    }
 
    if (parsed->xinfo & XACT_XINFO_HAS_DBINFO)
    {
        xl_xact_dbinfo *xl_dbinfo = (xl_xact_dbinfo *) data;
 
        parsed->dbId = xl_dbinfo->dbId;
        parsed->tsId = xl_dbinfo->tsId;
 
        data += sizeof(xl_xact_dbinfo);
    }
 
    if (parsed->xinfo & XACT_XINFO_HAS_SUBXACTS)
    {
        xl_xact_subxacts *xl_subxacts = (xl_xact_subxacts *) data;
 
        parsed->nsubxacts = xl_subxacts->nsubxacts;
        parsed->subxacts = xl_subxacts->subxacts;
 
        data += MinSizeOfXactSubxacts;
        data += parsed->nsubxacts * sizeof(TransactionId);
    }
 
    if (parsed->xinfo & XACT_XINFO_HAS_RELFILELOCATORS)
    {
        xl_xact_relfilelocators *xl_rellocators = (xl_xact_relfilelocators *) data;
 
        parsed->nrels = xl_rellocators->nrels;
        parsed->xlocators = xl_rellocators->xlocators;
 
        data += MinSizeOfXactRelfileLocators;
        data += xl_rellocators->nrels * sizeof(RelFileLocator);
    }
 
    if (parsed->xinfo & XACT_XINFO_HAS_DROPPED_STATS)
    {
        xl_xact_stats_items *xl_drops = (xl_xact_stats_items *) data;
 
        parsed->nstats = xl_drops->nitems;
        parsed->stats = xl_drops->items;
 
        data += MinSizeOfXactStatsItems;
        data += xl_drops->nitems * sizeof(xl_xact_stats_item);
    }
 
    if (parsed->xinfo & XACT_XINFO_HAS_INVALS)
    {
        xl_xact_invals *xl_invals = (xl_xact_invals *) data;
 
        parsed->nmsgs = xl_invals->nmsgs;
        parsed->msgs = xl_invals->msgs;
 
        data += MinSizeOfXactInvals;
        data += xl_invals->nmsgs * sizeof(SharedInvalidationMessage);
    }
 
    if (parsed->xinfo & XACT_XINFO_HAS_TWOPHASE)
    {
        xl_xact_twophase *xl_twophase = (xl_xact_twophase *) data;
 
        parsed->twophase_xid = xl_twophase->xid;
 
        data += sizeof(xl_xact_twophase);
 
        if (parsed->xinfo & XACT_XINFO_HAS_GID)
        {
            strlcpy(parsed->twophase_gid, data, sizeof(parsed->twophase_gid));
            data += strlen(data) + 1;
        }
    }
 
    /* Note: no alignment is guaranteed after this point */
 
    if (parsed->xinfo & XACT_XINFO_HAS_ORIGIN)
    {
        xl_xact_origin xl_origin;
 
        /* no alignment is guaranteed, so copy onto stack */
        memcpy(&xl_origin, data, sizeof(xl_origin));
 
        parsed->origin_lsn = xl_origin.origin_lsn;
        parsed->origin_timestamp = xl_origin.origin_timestamp;
 
        data += sizeof(xl_xact_origin);
    }
}
 
void
ParseAbortRecord(uint8 info, xl_xact_abort *xlrec, xl_xact_parsed_abort *parsed)
{
    char       *data = ((char *) xlrec) + MinSizeOfXactAbort;
 
    memset(parsed, 0, sizeof(*parsed));
 
    parsed->xinfo = 0;          /* default, if no XLOG_XACT_HAS_INFO is
                                 * present */
 
    parsed->xact_time = xlrec->xact_time;
 
    if (info & XLOG_XACT_HAS_INFO)
    {
        xl_xact_xinfo *xl_xinfo = (xl_xact_xinfo *) data;
 
        parsed->xinfo = xl_xinfo->xinfo;
 
        data += sizeof(xl_xact_xinfo);
    }
 
    if (parsed->xinfo & XACT_XINFO_HAS_DBINFO)
    {
        xl_xact_dbinfo *xl_dbinfo = (xl_xact_dbinfo *) data;
 
        parsed->dbId = xl_dbinfo->dbId;
        parsed->tsId = xl_dbinfo->tsId;
 
        data += sizeof(xl_xact_dbinfo);
    }
 
    if (parsed->xinfo & XACT_XINFO_HAS_SUBXACTS)
    {
        xl_xact_subxacts *xl_subxacts = (xl_xact_subxacts *) data;
 
        parsed->nsubxacts = xl_subxacts->nsubxacts;
        parsed->subxacts = xl_subxacts->subxacts;
 
        data += MinSizeOfXactSubxacts;
        data += parsed->nsubxacts * sizeof(TransactionId);
    }
 
    if (parsed->xinfo & XACT_XINFO_HAS_RELFILELOCATORS)
    {
        xl_xact_relfilelocators *xl_rellocator = (xl_xact_relfilelocators *) data;
 
        parsed->nrels = xl_rellocator->nrels;
        parsed->xlocators = xl_rellocator->xlocators;
 
        data += MinSizeOfXactRelfileLocators;
        data += xl_rellocator->nrels * sizeof(RelFileLocator);
    }
 
    if (parsed->xinfo & XACT_XINFO_HAS_DROPPED_STATS)
    {
        xl_xact_stats_items *xl_drops = (xl_xact_stats_items *) data;
 
        parsed->nstats = xl_drops->nitems;
        parsed->stats = xl_drops->items;
 
        data += MinSizeOfXactStatsItems;
        data += xl_drops->nitems * sizeof(xl_xact_stats_item);
    }
 
    if (parsed->xinfo & XACT_XINFO_HAS_TWOPHASE)
    {
        xl_xact_twophase *xl_twophase = (xl_xact_twophase *) data;
 
        parsed->twophase_xid = xl_twophase->xid;
 
        data += sizeof(xl_xact_twophase);
 
        if (parsed->xinfo & XACT_XINFO_HAS_GID)
        {
            strlcpy(parsed->twophase_gid, data, sizeof(parsed->twophase_gid));
            data += strlen(data) + 1;
        }
    }
 
    /* Note: no alignment is guaranteed after this point */
 
    if (parsed->xinfo & XACT_XINFO_HAS_ORIGIN)
    {
        xl_xact_origin xl_origin;
 
        /* no alignment is guaranteed, so copy onto stack */
        memcpy(&xl_origin, data, sizeof(xl_origin));
 
        parsed->origin_lsn = xl_origin.origin_lsn;
        parsed->origin_timestamp = xl_origin.origin_timestamp;
 
        data += sizeof(xl_xact_origin);
    }
}
 
/*
 * ParsePrepareRecord
 */
void
ParsePrepareRecord(uint8 info, xl_xact_prepare *xlrec, xl_xact_parsed_prepare *parsed)
{
    char       *bufptr;
 
    bufptr = ((char *) xlrec) + MAXALIGN(sizeof(xl_xact_prepare));
 
    memset(parsed, 0, sizeof(*parsed));
 
    parsed->xact_time = xlrec->prepared_at;
    parsed->origin_lsn = xlrec->origin_lsn;
    parsed->origin_timestamp = xlrec->origin_timestamp;
    parsed->twophase_xid = xlrec->xid;
    parsed->dbId = xlrec->database;
    parsed->nsubxacts = xlrec->nsubxacts;
    parsed->nrels = xlrec->ncommitrels;
    parsed->nabortrels = xlrec->nabortrels;
    parsed->nstats = xlrec->ncommitstats;
    parsed->nabortstats = xlrec->nabortstats;
    parsed->nmsgs = xlrec->ninvalmsgs;
 
    strncpy(parsed->twophase_gid, bufptr, xlrec->gidlen);
    bufptr += MAXALIGN(xlrec->gidlen);
 
    parsed->subxacts = (TransactionId *) bufptr;
    bufptr += MAXALIGN(xlrec->nsubxacts * sizeof(TransactionId));
 
    parsed->xlocators = (RelFileLocator *) bufptr;
    bufptr += MAXALIGN(xlrec->ncommitrels * sizeof(RelFileLocator));
 
    parsed->abortlocators = (RelFileLocator *) bufptr;
    bufptr += MAXALIGN(xlrec->nabortrels * sizeof(RelFileLocator));
 
    parsed->stats = (xl_xact_stats_item *) bufptr;
    bufptr += MAXALIGN(xlrec->ncommitstats * sizeof(xl_xact_stats_item));
 
    parsed->abortstats = (xl_xact_stats_item *) bufptr;
    bufptr += MAXALIGN(xlrec->nabortstats * sizeof(xl_xact_stats_item));
 
    parsed->msgs = (SharedInvalidationMessage *) bufptr;
    bufptr += MAXALIGN(xlrec->ninvalmsgs * sizeof(SharedInvalidationMessage));
}
 
static void
xact_desc_relations(StringInfo buf, char *label, int nrels,
                    RelFileLocator *xlocators)
{
    int         i;
 
    if (nrels > 0)
    {
        appendStringInfo(buf, "; %s:", label);
        for (i = 0; i < nrels; i++)
        {
            appendStringInfo(buf, " %s",
                             relpathperm(xlocators[i], MAIN_FORKNUM).str);
        }
    }
}
 
static void
xact_desc_subxacts(StringInfo buf, int nsubxacts, TransactionId *subxacts)
{
    int         i;
 
    if (nsubxacts > 0)
    {
        appendStringInfoString(buf, "; subxacts:");
        for (i = 0; i < nsubxacts; i++)
            appendStringInfo(buf, " %u", subxacts[i]);
    }
}
 
static void
xact_desc_stats(StringInfo buf, const char *label,
                int ndropped, xl_xact_stats_item *dropped_stats)
{
    int         i;
 
    if (ndropped > 0)
    {
        appendStringInfo(buf, "; %sdropped stats:", label);
        for (i = 0; i < ndropped; i++)
        {
            uint64      objid =
                ((uint64) dropped_stats[i].objid_hi) << 32 | dropped_stats[i].objid_lo;
 
            appendStringInfo(buf, " %d/%u/%" PRIu64,
                             dropped_stats[i].kind,
                             dropped_stats[i].dboid,
                             objid);
        }
    }
}
 
static void
xact_desc_commit(StringInfo buf, uint8 info, xl_xact_commit *xlrec, ReplOriginId origin_id)
{
    xl_xact_parsed_commit parsed;
 
    ParseCommitRecord(info, xlrec, &parsed);
 
    /* If this is a prepared xact, show the xid of the original xact */
    if (TransactionIdIsValid(parsed.twophase_xid))
        appendStringInfo(buf, "%u: ", parsed.twophase_xid);
 
    appendStringInfoString(buf, timestamptz_to_str(xlrec->xact_time));
 
    xact_desc_relations(buf, "rels", parsed.nrels, parsed.xlocators);
    xact_desc_subxacts(buf, parsed.nsubxacts, parsed.subxacts);
    xact_desc_stats(buf, "", parsed.nstats, parsed.stats);
 
    standby_desc_invalidations(buf, parsed.nmsgs, parsed.msgs, parsed.dbId,
                               parsed.tsId,
                               XactCompletionRelcacheInitFileInval(parsed.xinfo));
 
    if (XactCompletionApplyFeedback(parsed.xinfo))
        appendStringInfoString(buf, "; apply_feedback");
 
    if (XactCompletionForceSyncCommit(parsed.xinfo))
        appendStringInfoString(buf, "; sync");
 
    if (parsed.xinfo & XACT_XINFO_HAS_ORIGIN)
    {
        appendStringInfo(buf, "; origin: node %u, lsn %X/%08X, at %s",
                         origin_id,
                         LSN_FORMAT_ARGS(parsed.origin_lsn),
                         timestamptz_to_str(parsed.origin_timestamp));
    }
}
 
static void
xact_desc_abort(StringInfo buf, uint8 info, xl_xact_abort *xlrec, ReplOriginId origin_id)
{
    xl_xact_parsed_abort parsed;
 
    ParseAbortRecord(info, xlrec, &parsed);
 
    /* If this is a prepared xact, show the xid of the original xact */
    if (TransactionIdIsValid(parsed.twophase_xid))
        appendStringInfo(buf, "%u: ", parsed.twophase_xid);
 
    appendStringInfoString(buf, timestamptz_to_str(xlrec->xact_time));
 
    xact_desc_relations(buf, "rels", parsed.nrels, parsed.xlocators);
    xact_desc_subxacts(buf, parsed.nsubxacts, parsed.subxacts);
 
    if (parsed.xinfo & XACT_XINFO_HAS_ORIGIN)
    {
        appendStringInfo(buf, "; origin: node %u, lsn %X/%08X, at %s",
                         origin_id,
                         LSN_FORMAT_ARGS(parsed.origin_lsn),
                         timestamptz_to_str(parsed.origin_timestamp));
    }
 
    xact_desc_stats(buf, "", parsed.nstats, parsed.stats);
}
 
static void
xact_desc_prepare(StringInfo buf, uint8 info, xl_xact_prepare *xlrec, ReplOriginId origin_id)
{
    xl_xact_parsed_prepare parsed;
 
    ParsePrepareRecord(info, xlrec, &parsed);
 
    appendStringInfo(buf, "gid %s: ", parsed.twophase_gid);
    appendStringInfoString(buf, timestamptz_to_str(parsed.xact_time));
 
    xact_desc_relations(buf, "rels(commit)", parsed.nrels, parsed.xlocators);
    xact_desc_relations(buf, "rels(abort)", parsed.nabortrels,
                        parsed.abortlocators);
    xact_desc_stats(buf, "commit ", parsed.nstats, parsed.stats);
    xact_desc_stats(buf, "abort ", parsed.nabortstats, parsed.abortstats);
    xact_desc_subxacts(buf, parsed.nsubxacts, parsed.subxacts);
 
    standby_desc_invalidations(buf, parsed.nmsgs, parsed.msgs, parsed.dbId,
                               parsed.tsId, xlrec->initfileinval);
 
    /*
     * Check if the replication origin has been set in this record in the same
     * way as PrepareRedoAdd().
     */
    if (origin_id != InvalidReplOriginId)
        appendStringInfo(buf, "; origin: node %u, lsn %X/%08X, at %s",
                         origin_id,
                         LSN_FORMAT_ARGS(parsed.origin_lsn),
                         timestamptz_to_str(parsed.origin_timestamp));
}
 
static void
xact_desc_assignment(StringInfo buf, xl_xact_assignment *xlrec)
{
    int         i;
 
    appendStringInfoString(buf, "subxacts:");
 
    for (i = 0; i < xlrec->nsubxacts; i++)
        appendStringInfo(buf, " %u", xlrec->xsub[i]);
}
 
void
xact_desc(StringInfo buf, XLogReaderState *record)
{
    char       *rec = XLogRecGetData(record);
    uint8       info = XLogRecGetInfo(record) & XLOG_XACT_OPMASK;
 
    if (info == XLOG_XACT_COMMIT || info == XLOG_XACT_COMMIT_PREPARED)
    {
        xl_xact_commit *xlrec = (xl_xact_commit *) rec;
 
        xact_desc_commit(buf, XLogRecGetInfo(record), xlrec,
                         XLogRecGetOrigin(record));
    }
    else if (info == XLOG_XACT_ABORT || info == XLOG_XACT_ABORT_PREPARED)
    {
        xl_xact_abort *xlrec = (xl_xact_abort *) rec;
 
        xact_desc_abort(buf, XLogRecGetInfo(record), xlrec,
                        XLogRecGetOrigin(record));
    }
    else if (info == XLOG_XACT_PREPARE)
    {
        xl_xact_prepare *xlrec = (xl_xact_prepare *) rec;
 
        xact_desc_prepare(buf, XLogRecGetInfo(record), xlrec,
                          XLogRecGetOrigin(record));
    }
    else if (info == XLOG_XACT_ASSIGNMENT)
    {
        xl_xact_assignment *xlrec = (xl_xact_assignment *) rec;
 
        /*
         * Note that we ignore the WAL record's xid, since we're more
         * interested in the top-level xid that issued the record and which
         * xids are being reported here.
         */
        appendStringInfo(buf, "xtop %u: ", xlrec->xtop);
        xact_desc_assignment(buf, xlrec);
    }
    else if (info == XLOG_XACT_INVALIDATIONS)
    {
        xl_xact_invals *xlrec = (xl_xact_invals *) rec;
 
        standby_desc_invalidations(buf, xlrec->nmsgs, xlrec->msgs, InvalidOid,
                                   InvalidOid, false);
    }
}
 
const char *
xact_identify(uint8 info)
{
    const char *id = NULL;
 
    switch (info & XLOG_XACT_OPMASK)
    {
        case XLOG_XACT_COMMIT:
            id = "COMMIT";
            break;
        case XLOG_XACT_PREPARE:
            id = "PREPARE";
            break;
        case XLOG_XACT_ABORT:
            id = "ABORT";
            break;
        case XLOG_XACT_COMMIT_PREPARED:
            id = "COMMIT_PREPARED";
            break;
        case XLOG_XACT_ABORT_PREPARED:
            id = "ABORT_PREPARED";
            break;
        case XLOG_XACT_ASSIGNMENT:
            id = "ASSIGNMENT";
            break;
        case XLOG_XACT_INVALIDATIONS:
            id = "INVALIDATION";
            break;
    }
 
    return id;
}