/*-------------------------------------------------------------------------

 *

 * xlogdesc.c

 *    rmgr descriptor routines for access/transam/xlog.c

 *

 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group

 * Portions Copyright (c) 1994, Regents of the University of California

 *

 *

 * IDENTIFICATION

 *    src/backend/access/rmgrdesc/xlogdesc.c

 *

 *-------------------------------------------------------------------------

 */

#include "postgres.h"

#include "access/transam.h"

#include "access/xlog.h"

#include "access/xlog_internal.h"

#include "catalog/pg_control.h"

#include "utils/guc.h"

#include "utils/timestamp.h"

/*

 * GUC support

 */

const struct config_enum_entry wal_level_options[] = {

  {"minimal", WAL_LEVEL_MINIMAL, false},

  {"replica", WAL_LEVEL_REPLICA, false},

  {"archive", WAL_LEVEL_REPLICA, true}, /* deprecated */

  {"hot_standby", WAL_LEVEL_REPLICA, true}, /* deprecated */

  {"logical", WAL_LEVEL_LOGICAL, false},

  {NULL, 0, false}

};

/*

 * Find a string representation for wal_level

 */

static const char *

get_wal_level_string(int wal_level)

{

  const struct config_enum_entry *entry;

  const char *wal_level_str = "?";

  for (entry = wal_level_options; entry->name; entry++)

  {

    if (entry->val == wal_level)

    {

      wal_level_str = entry->name;

      break;

    }

  }

  return wal_level_str;

}

void

xlog_desc(StringInfo buf, XLogReaderState *record)

{

  char     *rec = XLogRecGetData(record);

  uint8   info = XLogRecGetInfo(record) & ~XLR_INFO_MASK;

  if (info == XLOG_CHECKPOINT_SHUTDOWN ||

    info == XLOG_CHECKPOINT_ONLINE)

  {

    CheckPoint *checkpoint = (CheckPoint *) rec;

    appendStringInfo(buf, "redo %X/%X; "

             "tli %u; prev tli %u; fpw %s; wal_level %s; xid %u:%u; oid %u; multi %u; offset %u; "

             "oldest xid %u in DB %u; oldest multi %u in DB %u; "

             "oldest/newest commit timestamp xid: %u/%u; "

             "oldest running xid %u; %s",

             LSN_FORMAT_ARGS(checkpoint->redo),

             checkpoint->ThisTimeLineID,

             checkpoint->PrevTimeLineID,

             checkpoint->fullPageWrites ? "true" : "false",

             get_wal_level_string(checkpoint->wal_level),

             EpochFromFullTransactionId(checkpoint->nextXid),

             XidFromFullTransactionId(checkpoint->nextXid),

             checkpoint->nextOid,

             checkpoint->nextMulti,

             checkpoint->nextMultiOffset,

             checkpoint->oldestXid,

             checkpoint->oldestXidDB,

             checkpoint->oldestMulti,

             checkpoint->oldestMultiDB,

             checkpoint->oldestCommitTsXid,

             checkpoint->newestCommitTsXid,

             checkpoint->oldestActiveXid,

             (info == XLOG_CHECKPOINT_SHUTDOWN) ? "shutdown" : "online");

  }

  else if (info == XLOG_NEXTOID)

  {

    Oid     nextOid;

    memcpy(&nextOid, rec, sizeof(Oid));

    appendStringInfo(buf, "%u", nextOid);

  }

  else if (info == XLOG_RESTORE_POINT)

  {

    xl_restore_point *xlrec = (xl_restore_point *) rec;

    appendStringInfoString(buf, xlrec->rp_name);

  }

  else if (info == XLOG_FPI || info == XLOG_FPI_FOR_HINT)

  {

    /* no further information to print */

  }

  else if (info == XLOG_BACKUP_END)

  {

    XLogRecPtr  startpoint;

    memcpy(&startpoint, rec, sizeof(XLogRecPtr));

    appendStringInfo(buf, "%X/%X", LSN_FORMAT_ARGS(startpoint));

  }

  else if (info == XLOG_PARAMETER_CHANGE)

  {

    xl_parameter_change xlrec;

    const char *wal_level_str;

    memcpy(&xlrec, rec, sizeof(xl_parameter_change));

    wal_level_str = get_wal_level_string(xlrec.wal_level);

    appendStringInfo(buf, "max_connections=%d max_worker_processes=%d "

             "max_wal_senders=%d max_prepared_xacts=%d "

             "max_locks_per_xact=%d wal_level=%s "

             "wal_log_hints=%s track_commit_timestamp=%s",

             xlrec.MaxConnections,

             xlrec.max_worker_processes,

             xlrec.max_wal_senders,

             xlrec.max_prepared_xacts,

             xlrec.max_locks_per_xact,

             wal_level_str,

             xlrec.wal_log_hints ? "on" : "off",

             xlrec.track_commit_timestamp ? "on" : "off");

  }

  else if (info == XLOG_FPW_CHANGE)

  {

    bool    fpw;

    memcpy(&fpw, rec, sizeof(bool));

    appendStringInfoString(buf, fpw ? "true" : "false");

  }

  else if (info == XLOG_END_OF_RECOVERY)

  {

    xl_end_of_recovery xlrec;

    memcpy(&xlrec, rec, sizeof(xl_end_of_recovery));

    appendStringInfo(buf, "tli %u; prev tli %u; time %s; wal_level %s",

             xlrec.ThisTimeLineID, xlrec.PrevTimeLineID,

             timestamptz_to_str(xlrec.end_time),

             get_wal_level_string(xlrec.wal_level));

  }

  else if (info == XLOG_OVERWRITE_CONTRECORD)

  {

    xl_overwrite_contrecord xlrec;

    memcpy(&xlrec, rec, sizeof(xl_overwrite_contrecord));

    appendStringInfo(buf, "lsn %X/%X; time %s",

             LSN_FORMAT_ARGS(xlrec.overwritten_lsn),

             timestamptz_to_str(xlrec.overwrite_time));

  }

  else if (info == XLOG_CHECKPOINT_REDO)

  {

    int     wal_level;

    memcpy(&wal_level, rec, sizeof(int));

    appendStringInfo(buf, "wal_level %s", get_wal_level_string(wal_level));

  }

}

const char *

xlog_identify(uint8 info)

{

  const char *id = NULL;

  switch (info & ~XLR_INFO_MASK)

  {

    case XLOG_CHECKPOINT_SHUTDOWN:

      id = "CHECKPOINT_SHUTDOWN";

      break;

    case XLOG_CHECKPOINT_ONLINE:

      id = "CHECKPOINT_ONLINE";

      break;

    case XLOG_NOOP:

      id = "NOOP";

      break;

    case XLOG_NEXTOID:

      id = "NEXTOID";

      break;

    case XLOG_SWITCH:

      id = "SWITCH";

      break;

    case XLOG_BACKUP_END:

      id = "BACKUP_END";

      break;

    case XLOG_PARAMETER_CHANGE:

      id = "PARAMETER_CHANGE";

      break;

    case XLOG_RESTORE_POINT:

      id = "RESTORE_POINT";

      break;

    case XLOG_FPW_CHANGE:

      id = "FPW_CHANGE";

      break;

    case XLOG_END_OF_RECOVERY:

      id = "END_OF_RECOVERY";

      break;

    case XLOG_OVERWRITE_CONTRECORD:

      id = "OVERWRITE_CONTRECORD";

      break;

    case XLOG_FPI:

      id = "FPI";

      break;

    case XLOG_FPI_FOR_HINT:

      id = "FPI_FOR_HINT";

      break;

    case XLOG_CHECKPOINT_REDO:

      id = "CHECKPOINT_REDO";

      break;

  }

  return id;

}

/*

 * Returns a string giving information about all the blocks in an

 * XLogRecord.

 */

void

XLogRecGetBlockRefInfo(XLogReaderState *record, bool pretty,

             bool detailed_format, StringInfo buf,

             uint32 *fpi_len)

{

  int     block_id;

  Assert(record != NULL);

  if (detailed_format && pretty)

    appendStringInfoChar(buf, '\n');

  for (block_id = 0; block_id <= XLogRecMaxBlockId(record); block_id++)

  {

    RelFileLocator rlocator;

    ForkNumber  forknum;

    BlockNumber blk;

    if (!XLogRecGetBlockTagExtended(record, block_id,

                    &rlocator, &forknum, &blk, NULL))

      continue;

    if (detailed_format)

    {

      /* Get block references in detailed format. */

      if (pretty)

        appendStringInfoChar(buf, '\t');

      else if (block_id > 0)

        appendStringInfoChar(buf, ' ');

      appendStringInfo(buf,

               "blkref #%d: rel %u/%u/%u fork %s blk %u",

               block_id,

               rlocator.spcOid, rlocator.dbOid, rlocator.relNumber,

               forkNames[forknum],

               blk);

      if (XLogRecHasBlockImage(record, block_id))

      {

        uint8   bimg_info = XLogRecGetBlock(record, block_id)->bimg_info;

        /* Calculate the amount of FPI data in the record. */

        if (fpi_len)

          *fpi_len += XLogRecGetBlock(record, block_id)->bimg_len;

        if (BKPIMAGE_COMPRESSED(bimg_info))

        {

          const char *method;

          if ((bimg_info & BKPIMAGE_COMPRESS_PGLZ) != 0)

            method = "pglz";

          else if ((bimg_info & BKPIMAGE_COMPRESS_LZ4) != 0)

            method = "lz4";

          else if ((bimg_info & BKPIMAGE_COMPRESS_ZSTD) != 0)

            method = "zstd";

          else

            method = "unknown";

          appendStringInfo(buf,

                   " (FPW%s); hole: offset: %u, length: %u, "

                   "compression saved: %u, method: %s",

                   XLogRecBlockImageApply(record, block_id) ?

                   "" : " for WAL verification",

                   XLogRecGetBlock(record, block_id)->hole_offset,

                   XLogRecGetBlock(record, block_id)->hole_length,

                   BLCKSZ -

                   XLogRecGetBlock(record, block_id)->hole_length -

                   XLogRecGetBlock(record, block_id)->bimg_len,

                   method);

        }

        else

        {

          appendStringInfo(buf,

                   " (FPW%s); hole: offset: %u, length: %u",

                   XLogRecBlockImageApply(record, block_id) ?

                   "" : " for WAL verification",

                   XLogRecGetBlock(record, block_id)->hole_offset,

                   XLogRecGetBlock(record, block_id)->hole_length);

        }

      }

      if (pretty)

        appendStringInfoChar(buf, '\n');

    }

    else

    {

      /* Get block references in short format. */

      if (forknum != MAIN_FORKNUM)

      {

        appendStringInfo(buf,

                 ", blkref #%d: rel %u/%u/%u fork %s blk %u",

                 block_id,

                 rlocator.spcOid, rlocator.dbOid, rlocator.relNumber,

                 forkNames[forknum],

                 blk);

      }

      else

      {

        appendStringInfo(buf,

                 ", blkref #%d: rel %u/%u/%u blk %u",

                 block_id,

                 rlocator.spcOid, rlocator.dbOid, rlocator.relNumber,

                 blk);

      }

      if (XLogRecHasBlockImage(record, block_id))

      {

        /* Calculate the amount of FPI data in the record. */

        if (fpi_len)

          *fpi_len += XLogRecGetBlock(record, block_id)->bimg_len;

        if (XLogRecBlockImageApply(record, block_id))

          appendStringInfoString(buf, " FPW");

        else

          appendStringInfoString(buf, " FPW for WAL verification");

      }

    }

  }

  if (!detailed_format && pretty)

    appendStringInfoChar(buf, '\n');

}