Quelle  pg_controldata.c

/*-------------------------------------------------------------------------
 *
 * pg_controldata.c
 *
 * Routines to expose the contents of the control data file via
 * a set of SQL functions.
 *
 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * IDENTIFICATION
 *   src/backend/utils/misc/pg_controldata.c
 *-------------------------------------------------------------------------
 */

#include "postgres.h"

#include "access/htup_details.h"
#include "access/transam.h"
#include "access/xlog.h"
#include "access/xlog_internal.h"
#include "catalog/pg_control.h"
#include "common/controldata_utils.h"
#include "funcapi.h"
#include "miscadmin.h"
#include "storage/lwlock.h"
#include "utils/builtins.h"
#include "utils/pg_lsn.h"
#include "utils/timestamp.h"

Datum
pg_control_system(PG_FUNCTION_ARGS)
{
 Datum  values[4];
 bool  nulls[4];
 TupleDesc tupdesc;
 HeapTuple htup;
 ControlFileData *ControlFile;
 bool  crc_ok;

 if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
  elog(ERROR, "return type must be a row type");

 /* read the control file */
 LWLockAcquire(ControlFileLock, LW_SHARED);
 ControlFile = get_controlfile(DataDir, &crc_ok);
 LWLockRelease(ControlFileLock);
 if (!crc_ok)
  ereport(ERROR,
    (errmsg("calculated CRC checksum does not match value stored in file")));

 values[0] = Int32GetDatum(ControlFile->pg_control_version);
 nulls[0] = false;

 values[1] = Int32GetDatum(ControlFile->catalog_version_no);
 nulls[1] = false;

 values[2] = Int64GetDatum(ControlFile->system_identifier);
 nulls[2] = false;

 values[3] = TimestampTzGetDatum(time_t_to_timestamptz(ControlFile->time));
 nulls[3] = false;

 htup = heap_form_tuple(tupdesc, values, nulls);

 PG_RETURN_DATUM(HeapTupleGetDatum(htup));
}

Datum
pg_control_checkpoint(PG_FUNCTION_ARGS)
{
 Datum  values[18];
 bool  nulls[18];
 TupleDesc tupdesc;
 HeapTuple htup;
 ControlFileData *ControlFile;
 XLogSegNo segno;
 char  xlogfilename[MAXFNAMELEN];
 bool  crc_ok;

 if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
  elog(ERROR, "return type must be a row type");

 /* Read the control file. */
 LWLockAcquire(ControlFileLock, LW_SHARED);
 ControlFile = get_controlfile(DataDir, &crc_ok);
 LWLockRelease(ControlFileLock);
 if (!crc_ok)
  ereport(ERROR,
    (errmsg("calculated CRC checksum does not match value stored in file")));

 /*
  * Calculate name of the WAL file containing the latest checkpoint's REDO
  * start point.
 */
 XLByteToSeg(ControlFile->checkPointCopy.redo, segno, wal_segment_size);
 XLogFileName(xlogfilename, ControlFile->checkPointCopy.ThisTimeLineID,
     segno, wal_segment_size);

 /* Populate the values and null arrays */
 values[0] = LSNGetDatum(ControlFile->checkPoint);
 nulls[0] = false;

 values[1] = LSNGetDatum(ControlFile->checkPointCopy.redo);
 nulls[1] = false;

 values[2] = CStringGetTextDatum(xlogfilename);
 nulls[2] = false;

 values[3] = Int32GetDatum(ControlFile->checkPointCopy.ThisTimeLineID);
 nulls[3] = false;

 values[4] = Int32GetDatum(ControlFile->checkPointCopy.PrevTimeLineID);
 nulls[4] = false;

 values[5] = BoolGetDatum(ControlFile->checkPointCopy.fullPageWrites);
 nulls[5] = false;

 values[6] = CStringGetTextDatum(psprintf("%u:%u",
            EpochFromFullTransactionId(ControlFile->checkPointCopy.nextXid),
            XidFromFullTransactionId(ControlFile->checkPointCopy.nextXid)));
 nulls[6] = false;

 values[7] = ObjectIdGetDatum(ControlFile->checkPointCopy.nextOid);
 nulls[7] = false;

 values[8] = TransactionIdGetDatum(ControlFile->checkPointCopy.nextMulti);
 nulls[8] = false;

 values[9] = TransactionIdGetDatum(ControlFile->checkPointCopy.nextMultiOffset);
 nulls[9] = false;

 values[10] = TransactionIdGetDatum(ControlFile->checkPointCopy.oldestXid);
 nulls[10] = false;

 values[11] = ObjectIdGetDatum(ControlFile->checkPointCopy.oldestXidDB);
 nulls[11] = false;

 values[12] = TransactionIdGetDatum(ControlFile->checkPointCopy.oldestActiveXid);
 nulls[12] = false;

 values[13] = TransactionIdGetDatum(ControlFile->checkPointCopy.oldestMulti);
 nulls[13] = false;

 values[14] = ObjectIdGetDatum(ControlFile->checkPointCopy.oldestMultiDB);
 nulls[14] = false;

 values[15] = TransactionIdGetDatum(ControlFile->checkPointCopy.oldestCommitTsXid);
 nulls[15] = false;

 values[16] = TransactionIdGetDatum(ControlFile->checkPointCopy.newestCommitTsXid);
 nulls[16] = false;

 values[17] = TimestampTzGetDatum(time_t_to_timestamptz(ControlFile->checkPointCopy.time));
 nulls[17] = false;

 htup = heap_form_tuple(tupdesc, values, nulls);

 PG_RETURN_DATUM(HeapTupleGetDatum(htup));
}

Datum
pg_control_recovery(PG_FUNCTION_ARGS)
{
 Datum  values[5];
 bool  nulls[5];
 TupleDesc tupdesc;
 HeapTuple htup;
 ControlFileData *ControlFile;
 bool  crc_ok;

 if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
  elog(ERROR, "return type must be a row type");

 /* read the control file */
 LWLockAcquire(ControlFileLock, LW_SHARED);
 ControlFile = get_controlfile(DataDir, &crc_ok);
 LWLockRelease(ControlFileLock);
 if (!crc_ok)
  ereport(ERROR,
    (errmsg("calculated CRC checksum does not match value stored in file")));

 values[0] = LSNGetDatum(ControlFile->minRecoveryPoint);
 nulls[0] = false;

 values[1] = Int32GetDatum(ControlFile->minRecoveryPointTLI);
 nulls[1] = false;

 values[2] = LSNGetDatum(ControlFile->backupStartPoint);
 nulls[2] = false;

 values[3] = LSNGetDatum(ControlFile->backupEndPoint);
 nulls[3] = false;

 values[4] = BoolGetDatum(ControlFile->backupEndRequired);
 nulls[4] = false;

 htup = heap_form_tuple(tupdesc, values, nulls);

 PG_RETURN_DATUM(HeapTupleGetDatum(htup));
}

Datum
pg_control_init(PG_FUNCTION_ARGS)
{
 Datum  values[12];
 bool  nulls[12];
 TupleDesc tupdesc;
 HeapTuple htup;
 ControlFileData *ControlFile;
 bool  crc_ok;

 if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
  elog(ERROR, "return type must be a row type");

 /* read the control file */
 LWLockAcquire(ControlFileLock, LW_SHARED);
 ControlFile = get_controlfile(DataDir, &crc_ok);
 LWLockRelease(ControlFileLock);
 if (!crc_ok)
  ereport(ERROR,
    (errmsg("calculated CRC checksum does not match value stored in file")));

 values[0] = Int32GetDatum(ControlFile->maxAlign);
 nulls[0] = false;

 values[1] = Int32GetDatum(ControlFile->blcksz);
 nulls[1] = false;

 values[2] = Int32GetDatum(ControlFile->relseg_size);
 nulls[2] = false;

 values[3] = Int32GetDatum(ControlFile->xlog_blcksz);
 nulls[3] = false;

 values[4] = Int32GetDatum(ControlFile->xlog_seg_size);
 nulls[4] = false;

 values[5] = Int32GetDatum(ControlFile->nameDataLen);
 nulls[5] = false;

 values[6] = Int32GetDatum(ControlFile->indexMaxKeys);
 nulls[6] = false;

 values[7] = Int32GetDatum(ControlFile->toast_max_chunk_size);
 nulls[7] = false;

 values[8] = Int32GetDatum(ControlFile->loblksize);
 nulls[8] = false;

 values[9] = BoolGetDatum(ControlFile->float8ByVal);
 nulls[9] = false;

 values[10] = Int32GetDatum(ControlFile->data_checksum_version);
 nulls[10] = false;

 values[11] = BoolGetDatum(ControlFile->default_char_signedness);
 nulls[11] = false;

 htup = heap_form_tuple(tupdesc, values, nulls);

 PG_RETURN_DATUM(HeapTupleGetDatum(htup));
}