#include "postgres.h"
#include "access/xact.h"
#include "access/xlog.h"
#include "access/xlog_internal.h"
#include "access/xloginsert.h"
#include "catalog/pg_control.h"
#include "common/pg_lzcompress.h"
#include "executor/instrument.h"
#include "miscadmin.h"
#include "pg_trace.h"
#include "replication/origin.h"
#include "storage/bufmgr.h"
#include "storage/proc.h"
#include "utils/memutils.h"
#include "utils/pgstat_internal.h"

Include dependency graph for xloginsert.c:

Data Structures
struct	registered_buffer

Macros
#define	LZ4_MAX_BLCKSZ 0

#define	ZSTD_MAX_BLCKSZ 0

#define	PGLZ_MAX_BLCKSZ PGLZ_MAX_OUTPUT(BLCKSZ)

#define	COMPRESS_BUFSIZE Max(Max(PGLZ_MAX_BLCKSZ, LZ4_MAX_BLCKSZ), ZSTD_MAX_BLCKSZ)

#define	SizeOfXlogOrigin (sizeof(RepOriginId) + sizeof(char))

#define	SizeOfXLogTransactionId (sizeof(TransactionId) + sizeof(char))

#define	HEADER_SCRATCH_SIZE

Functions
static XLogRecData *	XLogRecordAssemble (RmgrId rmid, uint8 info, XLogRecPtr RedoRecPtr, bool doPageWrites, XLogRecPtr fpw_lsn, int num_fpi, uint64 fpi_bytes, bool topxid_included)

static bool	XLogCompressBackupBlock (const PageData page, uint16 hole_offset, uint16 hole_length, void dest, uint16 *dlen)

void	XLogBeginInsert (void)

void	XLogEnsureRecordSpace (int max_block_id, int ndatas)

void	XLogResetInsertion (void)

void	XLogRegisterBuffer (uint8 block_id, Buffer buffer, uint8 flags)

void	XLogRegisterBlock (uint8 block_id, RelFileLocator rlocator, ForkNumber forknum, BlockNumber blknum, const PageData page, uint8 flags)

void	XLogRegisterData (const void *data, uint32 len)

void	XLogRegisterBufData (uint8 block_id, const void *data, uint32 len)

void	XLogSetRecordFlags (uint8 flags)

XLogRecPtr	XLogInsert (RmgrId rmid, uint8 info)

XLogRecPtr	XLogSimpleInsertInt64 (RmgrId rmid, uint8 info, int64 value)

bool	XLogCheckBufferNeedsBackup (Buffer buffer)

XLogRecPtr	XLogSaveBufferForHint (Buffer buffer, bool buffer_std)

XLogRecPtr	log_newpage (RelFileLocator *rlocator, ForkNumber forknum, BlockNumber blkno, Page page, bool page_std)

void	log_newpages (RelFileLocator rlocator, ForkNumber forknum, int num_pages, BlockNumber blknos, Page *pages, bool page_std)

XLogRecPtr	log_newpage_buffer (Buffer buffer, bool page_std)

void	log_newpage_range (Relation rel, ForkNumber forknum, BlockNumber startblk, BlockNumber endblk, bool page_std)

void	InitXLogInsert (void)

Macro Definition Documentation

◆ COMPRESS_BUFSIZE

#define COMPRESS_BUFSIZE Max(Max(PGLZ_MAX_BLCKSZ, LZ4_MAX_BLCKSZ), ZSTD_MAX_BLCKSZ)

Definition at line 64 of file xloginsert.c.

◆ HEADER_SCRATCH_SIZE

#define HEADER_SCRATCH_SIZE

Value:

    (SizeOfXLogRecord + \
     MaxSizeOfXLogRecordBlockHeader * (XLR_MAX_BLOCK_ID + 1) + \
     SizeOfXLogRecordDataHeaderLong + SizeOfXlogOrigin + \
     SizeOfXLogTransactionId)

Definition at line 121 of file xloginsert.c.

{
    Assert(max_registered_block_id == 0);
    Assert(mainrdata_last == (XLogRecData *) &mainrdata_head);
    Assert(mainrdata_len == 0);
 
    /* cross-check on whether we should be here or not */
    if (!XLogInsertAllowed())
        elog(ERROR, "cannot make new WAL entries during recovery");
 
    if (begininsert_called)
        elog(ERROR, "XLogBeginInsert was already called");
 
    begininsert_called = true;
}
 
/*
 * Ensure that there are enough buffer and data slots in the working area,
 * for subsequent XLogRegisterBuffer, XLogRegisterData and XLogRegisterBufData
 * calls.
 *
 * There is always space for a small number of buffers and data chunks, enough
 * for most record types. This function is for the exceptional cases that need
 * more.
 */
void
XLogEnsureRecordSpace(int max_block_id, int ndatas)
{
    int         nbuffers;
 
    /*
     * This must be called before entering a critical section, because
     * allocating memory inside a critical section can fail. repalloc() will
     * check the same, but better to check it here too so that we fail
     * consistently even if the arrays happen to be large enough already.
     */
    Assert(CritSectionCount == 0);
 
    /* the minimum values can't be decreased */
    if (max_block_id < XLR_NORMAL_MAX_BLOCK_ID)
        max_block_id = XLR_NORMAL_MAX_BLOCK_ID;
    if (ndatas < XLR_NORMAL_RDATAS)
        ndatas = XLR_NORMAL_RDATAS;
 
    if (max_block_id > XLR_MAX_BLOCK_ID)
        elog(ERROR, "maximum number of WAL record block references exceeded");
    nbuffers = max_block_id + 1;
 
    if (nbuffers > max_registered_buffers)
    {
        registered_buffers = (registered_buffer *)
            repalloc(registered_buffers, sizeof(registered_buffer) * nbuffers);
 
        /*
         * At least the padding bytes in the structs must be zeroed, because
         * they are included in WAL data, but initialize it all for tidiness.
         */
        MemSet(&registered_buffers[max_registered_buffers], 0,
               (nbuffers - max_registered_buffers) * sizeof(registered_buffer));
        max_registered_buffers = nbuffers;
    }
 
    if (ndatas > max_rdatas)
    {
        rdatas = (XLogRecData *) repalloc(rdatas, sizeof(XLogRecData) * ndatas);
        max_rdatas = ndatas;
    }
}
 
/*
 * Reset WAL record construction buffers.
 */
void
XLogResetInsertion(void)
{
    int         i;
 
    for (i = 0; i < max_registered_block_id; i++)
        registered_buffers[i].in_use = false;
 
    num_rdatas = 0;
    max_registered_block_id = 0;
    mainrdata_len = 0;
    mainrdata_last = (XLogRecData *) &mainrdata_head;
    curinsert_flags = 0;
    begininsert_called = false;
}
 
/*
 * Register a reference to a buffer with the WAL record being constructed.
 * This must be called for every page that the WAL-logged operation modifies.
 */
void
XLogRegisterBuffer(uint8 block_id, Buffer buffer, uint8 flags)
{
    registered_buffer *regbuf;
 
    /* NO_IMAGE doesn't make sense with FORCE_IMAGE */
    Assert(!((flags & REGBUF_FORCE_IMAGE) && (flags & (REGBUF_NO_IMAGE))));
    Assert(begininsert_called);
 
    /*
     * Ordinarily, buffer should be exclusive-locked and marked dirty before
     * we get here, otherwise we could end up violating one of the rules in
     * access/transam/README.
     *
     * Some callers intentionally register a clean page and never update that
     * page's LSN; in that case they can pass the flag REGBUF_NO_CHANGE to
     * bypass these checks.
     */
#ifdef USE_ASSERT_CHECKING
    if (!(flags & REGBUF_NO_CHANGE))
        Assert(BufferIsLockedByMeInMode(buffer, BUFFER_LOCK_EXCLUSIVE) &&
               BufferIsDirty(buffer));
#endif
 
    if (block_id >= max_registered_block_id)
    {
        if (block_id >= max_registered_buffers)
            elog(ERROR, "too many registered buffers");
        max_registered_block_id = block_id + 1;
    }
 
    regbuf = &registered_buffers[block_id];
 
    BufferGetTag(buffer, &regbuf->rlocator, &regbuf->forkno, &regbuf->block);
    regbuf->page = BufferGetPage(buffer);
    regbuf->flags = flags;
    regbuf->rdata_tail = (XLogRecData *) &regbuf->rdata_head;
    regbuf->rdata_len = 0;
 
    /*
     * Check that this page hasn't already been registered with some other
     * block_id.
     */
#ifdef USE_ASSERT_CHECKING
    {
        int         i;
 
        for (i = 0; i < max_registered_block_id; i++)
        {
            registered_buffer *regbuf_old = &registered_buffers[i];
 
            if (i == block_id || !regbuf_old->in_use)
                continue;
 
            Assert(!RelFileLocatorEquals(regbuf_old->rlocator, regbuf->rlocator) ||
                   regbuf_old->forkno != regbuf->forkno ||
                   regbuf_old->block != regbuf->block);
        }
    }
#endif
 
    regbuf->in_use = true;
}
 
/*
 * Like XLogRegisterBuffer, but for registering a block that's not in the
 * shared buffer pool (i.e. when you don't have a Buffer for it).
 */
void
XLogRegisterBlock(uint8 block_id, RelFileLocator *rlocator, ForkNumber forknum,
                  BlockNumber blknum, const PageData *page, uint8 flags)
{
    registered_buffer *regbuf;
 
    Assert(begininsert_called);
 
    if (block_id >= max_registered_block_id)
        max_registered_block_id = block_id + 1;
 
    if (block_id >= max_registered_buffers)
        elog(ERROR, "too many registered buffers");
 
    regbuf = &registered_buffers[block_id];
 
    regbuf->rlocator = *rlocator;
    regbuf->forkno = forknum;
    regbuf->block = blknum;
    regbuf->page = page;
    regbuf->flags = flags;
    regbuf->rdata_tail = (XLogRecData *) &regbuf->rdata_head;
    regbuf->rdata_len = 0;
 
    /*
     * Check that this page hasn't already been registered with some other
     * block_id.
     */
#ifdef USE_ASSERT_CHECKING
    {
        int         i;
 
        for (i = 0; i < max_registered_block_id; i++)
        {
            registered_buffer *regbuf_old = &registered_buffers[i];
 
            if (i == block_id || !regbuf_old->in_use)
                continue;
 
            Assert(!RelFileLocatorEquals(regbuf_old->rlocator, regbuf->rlocator) ||
                   regbuf_old->forkno != regbuf->forkno ||
                   regbuf_old->block != regbuf->block);
        }
    }
#endif
 
    regbuf->in_use = true;
}
 
/*
 * Add data to the WAL record that's being constructed.
 *
 * The data is appended to the "main chunk", available at replay with
 * XLogRecGetData().
 */
void
XLogRegisterData(const void *data, uint32 len)
{
    XLogRecData *rdata;
 
    Assert(begininsert_called);
 
    if (num_rdatas >= max_rdatas)
        ereport(ERROR,
                (errmsg_internal("too much WAL data"),
                 errdetail_internal("%d out of %d data segments are already in use.",
                                    num_rdatas, max_rdatas)));
    rdata = &rdatas[num_rdatas++];
 
    rdata->data = data;
    rdata->len = len;
 
    /*
     * we use the mainrdata_last pointer to track the end of the chain, so no
     * need to clear 'next' here.
     */
 
    mainrdata_last->next = rdata;
    mainrdata_last = rdata;
 
    mainrdata_len += len;
}
 
/*
 * Add buffer-specific data to the WAL record that's being constructed.
 *
 * Block_id must reference a block previously registered with
 * XLogRegisterBuffer(). If this is called more than once for the same
 * block_id, the data is appended.
 *
 * The maximum amount of data that can be registered per block is 65535
 * bytes. That should be plenty; if you need more than BLCKSZ bytes to
 * reconstruct the changes to the page, you might as well just log a full
 * copy of it. (the "main data" that's not associated with a block is not
 * limited)
 */
void
XLogRegisterBufData(uint8 block_id, const void *data, uint32 len)
{
    registered_buffer *regbuf;
    XLogRecData *rdata;
 
    Assert(begininsert_called);
 
    /* find the registered buffer struct */
    regbuf = &registered_buffers[block_id];
    if (!regbuf->in_use)
        elog(ERROR, "no block with id %d registered with WAL insertion",
             block_id);
 
    /*
     * Check against max_rdatas and ensure we do not register more data per
     * buffer than can be handled by the physical data format; i.e. that
     * regbuf->rdata_len does not grow beyond what
     * XLogRecordBlockHeader->data_length can hold.
     */
    if (num_rdatas >= max_rdatas)
        ereport(ERROR,
                (errmsg_internal("too much WAL data"),
                 errdetail_internal("%d out of %d data segments are already in use.",
                                    num_rdatas, max_rdatas)));
    if (regbuf->rdata_len + len > UINT16_MAX || len > UINT16_MAX)
        ereport(ERROR,
                (errmsg_internal("too much WAL data"),
                 errdetail_internal("Registering more than maximum %u bytes allowed to block %u: current %u bytes, adding %u bytes.",
                                    UINT16_MAX, block_id, regbuf->rdata_len, len)));
 
    rdata = &rdatas[num_rdatas++];
 
    rdata->data = data;
    rdata->len = len;
 
    regbuf->rdata_tail->next = rdata;
    regbuf->rdata_tail = rdata;
    regbuf->rdata_len += len;
}
 
/*
 * Set insert status flags for the upcoming WAL record.
 *
 * The flags that can be used here are:
 * - XLOG_INCLUDE_ORIGIN, to determine if the replication origin should be
 *   included in the record.
 * - XLOG_MARK_UNIMPORTANT, to signal that the record is not important for
 *   durability, which allows to avoid triggering WAL archiving and other
 *   background activity.
 */
void
XLogSetRecordFlags(uint8 flags)
{
    Assert(begininsert_called);
    curinsert_flags |= flags;
}
 
/*
 * Insert an XLOG record having the specified RMID and info bytes, with the
 * body of the record being the data and buffer references registered earlier
 * with XLogRegister* calls.
 *
 * Returns XLOG pointer to end of record (beginning of next record).
 * This can be used as LSN for data pages affected by the logged action.
 * (LSN is the XLOG point up to which the XLOG must be flushed to disk
 * before the data page can be written out.  This implements the basic
 * WAL rule "write the log before the data".)
 */
XLogRecPtr
XLogInsert(RmgrId rmid, uint8 info)
{
    XLogRecPtr  EndPos;
 
    /* XLogBeginInsert() must have been called. */
    if (!begininsert_called)
        elog(ERROR, "XLogBeginInsert was not called");
 
    /*
     * The caller can set rmgr bits, XLR_SPECIAL_REL_UPDATE and
     * XLR_CHECK_CONSISTENCY; the rest are reserved for use by me.
     */
    if ((info & ~(XLR_RMGR_INFO_MASK |
                  XLR_SPECIAL_REL_UPDATE |
                  XLR_CHECK_CONSISTENCY)) != 0)
        elog(PANIC, "invalid xlog info mask %02X", info);
 
    TRACE_POSTGRESQL_WAL_INSERT(rmid, info);
 
    /*
     * In bootstrap mode, we don't actually log anything but XLOG resources;
     * return a phony record pointer.
     */
    if (IsBootstrapProcessingMode() && rmid != RM_XLOG_ID)
    {
        XLogResetInsertion();
        EndPos = SizeOfXLogLongPHD; /* start of 1st chkpt record */
        return EndPos;
    }
 
    do
    {
        XLogRecPtr  RedoRecPtr;
        bool        doPageWrites;
        bool        topxid_included = false;
        XLogRecPtr  fpw_lsn;
        XLogRecData *rdt;
        int         num_fpi = 0;
        uint64      fpi_bytes = 0;
 
        /*
         * Get values needed to decide whether to do full-page writes. Since
         * we don't yet have an insertion lock, these could change under us,
         * but XLogInsertRecord will recheck them once it has a lock.
         */
        GetFullPageWriteInfo(&RedoRecPtr, &doPageWrites);
 
        rdt = XLogRecordAssemble(rmid, info, RedoRecPtr, doPageWrites,
                                 &fpw_lsn, &num_fpi, &fpi_bytes,
                                 &topxid_included);
 
        EndPos = XLogInsertRecord(rdt, fpw_lsn, curinsert_flags, num_fpi,
                                  fpi_bytes, topxid_included);
    } while (!XLogRecPtrIsValid(EndPos));
 
    XLogResetInsertion();
 
    return EndPos;
}
 
/*
 * Simple wrapper to XLogInsert to insert a WAL record with elementary
 * contents (only an int64 is supported as value currently).
 */
XLogRecPtr
XLogSimpleInsertInt64(RmgrId rmid, uint8 info, int64 value)
{
    XLogBeginInsert();
    XLogRegisterData(&value, sizeof(value));
    return XLogInsert(rmid, info);
}
 
/*
 * Assemble a WAL record from the registered data and buffers into an
 * XLogRecData chain, ready for insertion with XLogInsertRecord().
 *
 * The record header fields are filled in, except for the xl_prev field. The
 * calculated CRC does not include the record header yet.
 *
 * If there are any registered buffers, and a full-page image was not taken
 * of all of them, *fpw_lsn is set to the lowest LSN among such pages. This
 * signals that the assembled record is only good for insertion on the
 * assumption that the RedoRecPtr and doPageWrites values were up-to-date.
 *
 * *topxid_included is set if the topmost transaction ID is logged with the
 * current subtransaction.
 */
static XLogRecData *
XLogRecordAssemble(RmgrId rmid, uint8 info,
                   XLogRecPtr RedoRecPtr, bool doPageWrites,
                   XLogRecPtr *fpw_lsn, int *num_fpi, uint64 *fpi_bytes,
                   bool *topxid_included)
{
    XLogRecData *rdt;
    uint64      total_len = 0;
    int         block_id;
    pg_crc32c   rdata_crc;
    registered_buffer *prev_regbuf = NULL;
    XLogRecData *rdt_datas_last;
    XLogRecord *rechdr;
    char       *scratch = hdr_scratch;
 
    /*
     * Note: this function can be called multiple times for the same record.
     * All the modifications we do to the rdata chains below must handle that.
     */
 
    /* The record begins with the fixed-size header */
    rechdr = (XLogRecord *) scratch;
    scratch += SizeOfXLogRecord;
 
    hdr_rdt.next = NULL;
    rdt_datas_last = &hdr_rdt;
    hdr_rdt.data = hdr_scratch;
 
    /*
     * Enforce consistency checks for this record if user is looking for it.
     * Do this before at the beginning of this routine to give the possibility
     * for callers of XLogInsert() to pass XLR_CHECK_CONSISTENCY directly for
     * a record.
     */
    if (wal_consistency_checking[rmid])
        info |= XLR_CHECK_CONSISTENCY;
 
    /*
     * Make an rdata chain containing all the data portions of all block
     * references. This includes the data for full-page images. Also append
     * the headers for the block references in the scratch buffer.
     */
    *fpw_lsn = InvalidXLogRecPtr;
    for (block_id = 0; block_id < max_registered_block_id; block_id++)
    {
        registered_buffer *regbuf = &registered_buffers[block_id];
        bool        needs_backup;
        bool        needs_data;
        XLogRecordBlockHeader bkpb;
        XLogRecordBlockImageHeader bimg;
        XLogRecordBlockCompressHeader cbimg = {0};
        bool        samerel;
        bool        is_compressed = false;
        bool        include_image;
 
        if (!regbuf->in_use)
            continue;
 
        /* Determine if this block needs to be backed up */
        if (regbuf->flags & REGBUF_FORCE_IMAGE)
            needs_backup = true;
        else if (regbuf->flags & REGBUF_NO_IMAGE)
            needs_backup = false;
        else if (!doPageWrites)
            needs_backup = false;
        else
        {
            /*
             * We assume page LSN is first data on *every* page that can be
             * passed to XLogInsert, whether it has the standard page layout
             * or not.
             */
            XLogRecPtr  page_lsn = PageGetLSN(regbuf->page);
 
            needs_backup = (page_lsn <= RedoRecPtr);
            if (!needs_backup)
            {
                if (!XLogRecPtrIsValid(*fpw_lsn) || page_lsn < *fpw_lsn)
                    *fpw_lsn = page_lsn;
            }
        }
 
        /* Determine if the buffer data needs to included */
        if (regbuf->rdata_len == 0)
            needs_data = false;
        else if ((regbuf->flags & REGBUF_KEEP_DATA) != 0)
            needs_data = true;
        else
            needs_data = !needs_backup;
 
        bkpb.id = block_id;
        bkpb.fork_flags = regbuf->forkno;
        bkpb.data_length = 0;
 
        if ((regbuf->flags & REGBUF_WILL_INIT) == REGBUF_WILL_INIT)
            bkpb.fork_flags |= BKPBLOCK_WILL_INIT;
 
        /*
         * If needs_backup is true or WAL checking is enabled for current
         * resource manager, log a full-page write for the current block.
         */
        include_image = needs_backup || (info & XLR_CHECK_CONSISTENCY) != 0;
 
        if (include_image)
        {
            const PageData *page = regbuf->page;
            uint16      compressed_len = 0;
 
            /*
             * The page needs to be backed up, so calculate its hole length
             * and offset.
             */
            if (regbuf->flags & REGBUF_STANDARD)
            {
                /* Assume we can omit data between pd_lower and pd_upper */
                uint16      lower = ((PageHeader) page)->pd_lower;
                uint16      upper = ((PageHeader) page)->pd_upper;
 
                if (lower >= SizeOfPageHeaderData &&
                    upper > lower &&
                    upper <= BLCKSZ)
                {
                    bimg.hole_offset = lower;
                    cbimg.hole_length = upper - lower;
                }
                else
                {
                    /* No "hole" to remove */
                    bimg.hole_offset = 0;
                    cbimg.hole_length = 0;
                }
            }
            else
            {
                /* Not a standard page header, don't try to eliminate "hole" */
                bimg.hole_offset = 0;
                cbimg.hole_length = 0;
            }
 
            /*
             * Try to compress a block image if wal_compression is enabled
             */
            if (wal_compression != WAL_COMPRESSION_NONE)
            {
                is_compressed =
                    XLogCompressBackupBlock(page, bimg.hole_offset,
                                            cbimg.hole_length,
                                            regbuf->compressed_page,
                                            &compressed_len);
            }
 
            /*
             * Fill in the remaining fields in the XLogRecordBlockHeader
             * struct
             */
            bkpb.fork_flags |= BKPBLOCK_HAS_IMAGE;
 
            /* Report a full page image constructed for the WAL record */
            *num_fpi += 1;
 
            /*
             * Construct XLogRecData entries for the page content.
             */
            rdt_datas_last->next = &regbuf->bkp_rdatas[0];
            rdt_datas_last = rdt_datas_last->next;
 
            bimg.bimg_info = (cbimg.hole_length == 0) ? 0 : BKPIMAGE_HAS_HOLE;
 
            /*
             * If WAL consistency checking is enabled for the resource manager
             * of this WAL record, a full-page image is included in the record
             * for the block modified. During redo, the full-page is replayed
             * only if BKPIMAGE_APPLY is set.
             */
            if (needs_backup)
                bimg.bimg_info |= BKPIMAGE_APPLY;
 
            if (is_compressed)
            {
                /* The current compression is stored in the WAL record */
                bimg.length = compressed_len;
 
                /* Set the compression method used for this block */
                switch ((WalCompression) wal_compression)
                {
                    case WAL_COMPRESSION_PGLZ:
                        bimg.bimg_info |= BKPIMAGE_COMPRESS_PGLZ;
                        break;
 
                    case WAL_COMPRESSION_LZ4:
#ifdef USE_LZ4
                        bimg.bimg_info |= BKPIMAGE_COMPRESS_LZ4;
#else
                        elog(ERROR, "LZ4 is not supported by this build");
#endif
                        break;
 
                    case WAL_COMPRESSION_ZSTD:
#ifdef USE_ZSTD
                        bimg.bimg_info |= BKPIMAGE_COMPRESS_ZSTD;
#else
                        elog(ERROR, "zstd is not supported by this build");
#endif
                        break;
 
                    case WAL_COMPRESSION_NONE:
                        Assert(false);  /* cannot happen */
                        break;
                        /* no default case, so that compiler will warn */
                }
 
                rdt_datas_last->data = regbuf->compressed_page;
                rdt_datas_last->len = compressed_len;
            }
            else
            {
                bimg.length = BLCKSZ - cbimg.hole_length;
 
                if (cbimg.hole_length == 0)
                {
                    rdt_datas_last->data = page;
                    rdt_datas_last->len = BLCKSZ;
                }
                else
                {
                    /* must skip the hole */
                    rdt_datas_last->data = page;
                    rdt_datas_last->len = bimg.hole_offset;
 
                    rdt_datas_last->next = &regbuf->bkp_rdatas[1];
                    rdt_datas_last = rdt_datas_last->next;
 
                    rdt_datas_last->data =
                        page + (bimg.hole_offset + cbimg.hole_length);
                    rdt_datas_last->len =
                        BLCKSZ - (bimg.hole_offset + cbimg.hole_length);
                }
            }
 
            total_len += bimg.length;
 
            /* Track the WAL full page images in bytes */
            *fpi_bytes += bimg.length;
        }
 
        if (needs_data)
        {
            /*
             * When copying to XLogRecordBlockHeader, the length is narrowed
             * to an uint16.  Double-check that it is still correct.
             */
            Assert(regbuf->rdata_len <= UINT16_MAX);
 
            /*
             * Link the caller-supplied rdata chain for this buffer to the
             * overall list.
             */
            bkpb.fork_flags |= BKPBLOCK_HAS_DATA;
            bkpb.data_length = (uint16) regbuf->rdata_len;
            total_len += regbuf->rdata_len;
 
            rdt_datas_last->next = regbuf->rdata_head;
            rdt_datas_last = regbuf->rdata_tail;
        }
 
        if (prev_regbuf && RelFileLocatorEquals(regbuf->rlocator, prev_regbuf->rlocator))
        {
            samerel = true;
            bkpb.fork_flags |= BKPBLOCK_SAME_REL;
        }
        else
            samerel = false;
        prev_regbuf = regbuf;
 
        /* Ok, copy the header to the scratch buffer */
        memcpy(scratch, &bkpb, SizeOfXLogRecordBlockHeader);
        scratch += SizeOfXLogRecordBlockHeader;
        if (include_image)
        {
            memcpy(scratch, &bimg, SizeOfXLogRecordBlockImageHeader);
            scratch += SizeOfXLogRecordBlockImageHeader;
            if (cbimg.hole_length != 0 && is_compressed)
            {
                memcpy(scratch, &cbimg,
                       SizeOfXLogRecordBlockCompressHeader);
                scratch += SizeOfXLogRecordBlockCompressHeader;
            }
        }
        if (!samerel)
        {
            memcpy(scratch, &regbuf->rlocator, sizeof(RelFileLocator));
            scratch += sizeof(RelFileLocator);
        }
        memcpy(scratch, &regbuf->block, sizeof(BlockNumber));
        scratch += sizeof(BlockNumber);
    }
 
    /* followed by the record's origin, if any */
    if ((curinsert_flags & XLOG_INCLUDE_ORIGIN) &&
        replorigin_session_origin != InvalidRepOriginId)
    {
        *(scratch++) = (char) XLR_BLOCK_ID_ORIGIN;
        memcpy(scratch, &replorigin_session_origin, sizeof(replorigin_session_origin));
        scratch += sizeof(replorigin_session_origin);
    }
 
    /* followed by toplevel XID, if not already included in previous record */
    if (IsSubxactTopXidLogPending())
    {
        TransactionId xid = GetTopTransactionIdIfAny();
 
        /* Set the flag that the top xid is included in the WAL */
        *topxid_included = true;
 
        *(scratch++) = (char) XLR_BLOCK_ID_TOPLEVEL_XID;
        memcpy(scratch, &xid, sizeof(TransactionId));
        scratch += sizeof(TransactionId);
    }
 
    /* followed by main data, if any */
    if (mainrdata_len > 0)
    {
        if (mainrdata_len > 255)
        {
            uint32      mainrdata_len_4b;
 
            if (mainrdata_len > PG_UINT32_MAX)
                ereport(ERROR,
                        (errmsg_internal("too much WAL data"),
                         errdetail_internal("Main data length is %" PRIu64 " bytes for a maximum of %u bytes.",
                                            mainrdata_len,
                                            PG_UINT32_MAX)));
 
            mainrdata_len_4b = (uint32) mainrdata_len;
            *(scratch++) = (char) XLR_BLOCK_ID_DATA_LONG;
            memcpy(scratch, &mainrdata_len_4b, sizeof(uint32));
            scratch += sizeof(uint32);
        }
        else
        {
            *(scratch++) = (char) XLR_BLOCK_ID_DATA_SHORT;
            *(scratch++) = (uint8) mainrdata_len;
        }
        rdt_datas_last->next = mainrdata_head;
        rdt_datas_last = mainrdata_last;
        total_len += mainrdata_len;
    }
    rdt_datas_last->next = NULL;
 
    hdr_rdt.len = (scratch - hdr_scratch);
    total_len += hdr_rdt.len;
 
    /*
     * Calculate CRC of the data
     *
     * Note that the record header isn't added into the CRC initially since we
     * don't know the prev-link yet.  Thus, the CRC will represent the CRC of
     * the whole record in the order: rdata, then backup blocks, then record
     * header.
     */
    INIT_CRC32C(rdata_crc);
    COMP_CRC32C(rdata_crc, hdr_scratch + SizeOfXLogRecord, hdr_rdt.len - SizeOfXLogRecord);
    for (rdt = hdr_rdt.next; rdt != NULL; rdt = rdt->next)
        COMP_CRC32C(rdata_crc, rdt->data, rdt->len);
 
    /*
     * Ensure that the XLogRecord is not too large.
     *
     * XLogReader machinery is only able to handle records up to a certain
     * size (ignoring machine resource limitations), so make sure that we will
     * not emit records larger than the sizes advertised to be supported.
     */
    if (total_len > XLogRecordMaxSize)
        ereport(ERROR,
                (errmsg_internal("oversized WAL record"),
                 errdetail_internal("WAL record would be %" PRIu64 " bytes (of maximum %u bytes); rmid %u flags %u.",
                                    total_len, XLogRecordMaxSize, rmid, info)));
 
    /*
     * Fill in the fields in the record header. Prev-link is filled in later,
     * once we know where in the WAL the record will be inserted. The CRC does
     * not include the record header yet.
     */
    rechdr->xl_xid = GetCurrentTransactionIdIfAny();
    rechdr->xl_tot_len = (uint32) total_len;
    rechdr->xl_info = info;
    rechdr->xl_rmid = rmid;
    rechdr->xl_prev = InvalidXLogRecPtr;
    rechdr->xl_crc = rdata_crc;
 
    return &hdr_rdt;
}
 
/*
 * Create a compressed version of a backup block image.
 *
 * Returns false if compression fails (i.e., compressed result is actually
 * bigger than original). Otherwise, returns true and sets 'dlen' to
 * the length of compressed block image.
 */
static bool
XLogCompressBackupBlock(const PageData *page, uint16 hole_offset, uint16 hole_length,
                        void *dest, uint16 *dlen)
{
    int32       orig_len = BLCKSZ - hole_length;
    int32       len = -1;
    int32       extra_bytes = 0;
    const void *source;
    PGAlignedBlock tmp;
 
    if (hole_length != 0)
    {
        /* must skip the hole */
        memcpy(tmp.data, page, hole_offset);
        memcpy(tmp.data + hole_offset,
               page + (hole_offset + hole_length),
               BLCKSZ - (hole_length + hole_offset));
        source = tmp.data;
 
        /*
         * Extra data needs to be stored in WAL record for the compressed
         * version of block image if the hole exists.
         */
        extra_bytes = SizeOfXLogRecordBlockCompressHeader;
    }
    else
        source = page;
 
    switch ((WalCompression) wal_compression)
    {
        case WAL_COMPRESSION_PGLZ:
            len = pglz_compress(source, orig_len, dest, PGLZ_strategy_default);
            break;
 
        case WAL_COMPRESSION_LZ4:
#ifdef USE_LZ4
            len = LZ4_compress_default(source, dest, orig_len,
                                       COMPRESS_BUFSIZE);
            if (len <= 0)
                len = -1;       /* failure */
#else
            elog(ERROR, "LZ4 is not supported by this build");
#endif
            break;
 
        case WAL_COMPRESSION_ZSTD:
#ifdef USE_ZSTD
            len = ZSTD_compress(dest, COMPRESS_BUFSIZE, source, orig_len,
                                ZSTD_CLEVEL_DEFAULT);
            if (ZSTD_isError(len))
                len = -1;       /* failure */
#else
            elog(ERROR, "zstd is not supported by this build");
#endif
            break;
 
        case WAL_COMPRESSION_NONE:
            Assert(false);      /* cannot happen */
            break;
            /* no default case, so that compiler will warn */
    }
 
    /*
     * We recheck the actual size even if compression reports success and see
     * if the number of bytes saved by compression is larger than the length
     * of extra data needed for the compressed version of block image.
     */
    if (len >= 0 &&
        len + extra_bytes < orig_len)
    {
        *dlen = (uint16) len;   /* successful compression */
        return true;
    }
    return false;
}
 
/*
 * Determine whether the buffer referenced has to be backed up.
 *
 * Since we don't yet have the insert lock, fullPageWrites and runningBackups
 * (which forces full-page writes) could change later, so the result should
 * be used for optimization purposes only.
 */
bool
XLogCheckBufferNeedsBackup(Buffer buffer)
{
    XLogRecPtr  RedoRecPtr;
    bool        doPageWrites;
    Page        page;
 
    GetFullPageWriteInfo(&RedoRecPtr, &doPageWrites);
 
    page = BufferGetPage(buffer);
 
    if (doPageWrites && PageGetLSN(page) <= RedoRecPtr)
        return true;            /* buffer requires backup */
 
    return false;               /* buffer does not need to be backed up */
}
 
/*
 * Write a backup block if needed when we are setting a hint. Note that
 * this may be called for a variety of page types, not just heaps.
 *
 * Callable while holding just share lock on the buffer content.
 *
 * We can't use the plain backup block mechanism since that relies on the
 * Buffer being exclusively locked. Since some modifications (setting LSN, hint
 * bits) are allowed in a sharelocked buffer that can lead to wal checksum
 * failures. So instead we copy the page and insert the copied data as normal
 * record data.
 *
 * We only need to do something if page has not yet been full page written in
 * this checkpoint round. The LSN of the inserted wal record is returned if we
 * had to write, InvalidXLogRecPtr otherwise.
 *
 * It is possible that multiple concurrent backends could attempt to write WAL
 * records. In that case, multiple copies of the same block would be recorded
 * in separate WAL records by different backends, though that is still OK from
 * a correctness perspective.
 */
XLogRecPtr
XLogSaveBufferForHint(Buffer buffer, bool buffer_std)
{
    XLogRecPtr  recptr = InvalidXLogRecPtr;
    XLogRecPtr  lsn;
    XLogRecPtr  RedoRecPtr;
 
    /*
     * Ensure no checkpoint can change our view of RedoRecPtr.
     */
    Assert((MyProc->delayChkptFlags & DELAY_CHKPT_START) != 0);
 
    /*
     * Update RedoRecPtr so that we can make the right decision
     */
    RedoRecPtr = GetRedoRecPtr();
 
    /*
     * We assume page LSN is first data on *every* page that can be passed to
     * XLogInsert, whether it has the standard page layout or not. Since we're
     * only holding a share-lock on the page, we must take the buffer header
     * lock when we look at the LSN.
     */
    lsn = BufferGetLSNAtomic(buffer);
 
    if (lsn <= RedoRecPtr)
    {
        int         flags = 0;
        PGAlignedBlock copied_buffer;
        char       *origdata = (char *) BufferGetBlock(buffer);
        RelFileLocator rlocator;
        ForkNumber  forkno;
        BlockNumber blkno;
 
        /*
         * Copy buffer so we don't have to worry about concurrent hint bit or
         * lsn updates. We assume pd_lower/upper cannot be changed without an
         * exclusive lock, so the contents bkp are not racy.
         */
        if (buffer_std)
        {
            /* Assume we can omit data between pd_lower and pd_upper */
            Page        page = BufferGetPage(buffer);
            uint16      lower = ((PageHeader) page)->pd_lower;
            uint16      upper = ((PageHeader) page)->pd_upper;
 
            memcpy(copied_buffer.data, origdata, lower);
            memcpy(copied_buffer.data + upper, origdata + upper, BLCKSZ - upper);
        }
        else
            memcpy(copied_buffer.data, origdata, BLCKSZ);
 
        XLogBeginInsert();
 
        if (buffer_std)
            flags |= REGBUF_STANDARD;
 
        BufferGetTag(buffer, &rlocator, &forkno, &blkno);
        XLogRegisterBlock(0, &rlocator, forkno, blkno, copied_buffer.data, flags);
 
        recptr = XLogInsert(RM_XLOG_ID, XLOG_FPI_FOR_HINT);
    }
 
    return recptr;
}
 
/*
 * Write a WAL record containing a full image of a page. Caller is responsible
 * for writing the page to disk after calling this routine.
 *
 * Note: If you're using this function, you should be building pages in private
 * memory and writing them directly to smgr.  If you're using buffers, call
 * log_newpage_buffer instead.
 *
 * If the page follows the standard page layout, with a PageHeader and unused
 * space between pd_lower and pd_upper, set 'page_std' to true. That allows
 * the unused space to be left out from the WAL record, making it smaller.
 */
XLogRecPtr
log_newpage(RelFileLocator *rlocator, ForkNumber forknum, BlockNumber blkno,
            Page page, bool page_std)
{
    int         flags;
    XLogRecPtr  recptr;
 
    flags = REGBUF_FORCE_IMAGE;
    if (page_std)
        flags |= REGBUF_STANDARD;
 
    XLogBeginInsert();
    XLogRegisterBlock(0, rlocator, forknum, blkno, page, flags);
    recptr = XLogInsert(RM_XLOG_ID, XLOG_FPI);
 
    /*
     * The page may be uninitialized. If so, we can't set the LSN because that
     * would corrupt the page.
     */
    if (!PageIsNew(page))
    {
        PageSetLSN(page, recptr);
    }
 
    return recptr;
}
 
/*
 * Like log_newpage(), but allows logging multiple pages in one operation.
 * It is more efficient than calling log_newpage() for each page separately,
 * because we can write multiple pages in a single WAL record.
 */
void
log_newpages(RelFileLocator *rlocator, ForkNumber forknum, int num_pages,
             BlockNumber *blknos, Page *pages, bool page_std)
{
    int         flags;
    XLogRecPtr  recptr;
    int         i;
    int         j;
 
    flags = REGBUF_FORCE_IMAGE;
    if (page_std)
        flags |= REGBUF_STANDARD;
 
    /*
     * Iterate over all the pages. They are collected into batches of
     * XLR_MAX_BLOCK_ID pages, and a single WAL-record is written for each
     * batch.
     */
    XLogEnsureRecordSpace(XLR_MAX_BLOCK_ID - 1, 0);
 
    i = 0;
    while (i < num_pages)
    {
        int         batch_start = i;
        int         nbatch;
 
        XLogBeginInsert();
 
        nbatch = 0;
        while (nbatch < XLR_MAX_BLOCK_ID && i < num_pages)
        {
            XLogRegisterBlock(nbatch, rlocator, forknum, blknos[i], pages[i], flags);
            i++;
            nbatch++;
        }
 
        recptr = XLogInsert(RM_XLOG_ID, XLOG_FPI);
 
        for (j = batch_start; j < i; j++)
        {
            /*
             * The page may be uninitialized. If so, we can't set the LSN
             * because that would corrupt the page.
             */
            if (!PageIsNew(pages[j]))
            {
                PageSetLSN(pages[j], recptr);
            }
        }
    }
}
 
/*
 * Write a WAL record containing a full image of a page.
 *
 * Caller should initialize the buffer and mark it dirty before calling this
 * function.  This function will set the page LSN.
 *
 * If the page follows the standard page layout, with a PageHeader and unused
 * space between pd_lower and pd_upper, set 'page_std' to true. That allows
 * the unused space to be left out from the WAL record, making it smaller.
 */
XLogRecPtr
log_newpage_buffer(Buffer buffer, bool page_std)
{
    Page        page = BufferGetPage(buffer);
    RelFileLocator rlocator;
    ForkNumber  forknum;
    BlockNumber blkno;
 
    /* Shared buffers should be modified in a critical section. */
    Assert(CritSectionCount > 0);
 
    BufferGetTag(buffer, &rlocator, &forknum, &blkno);
 
    return log_newpage(&rlocator, forknum, blkno, page, page_std);
}
 
/*
 * WAL-log a range of blocks in a relation.
 *
 * An image of all pages with block numbers 'startblk' <= X < 'endblk' is
 * written to the WAL. If the range is large, this is done in multiple WAL
 * records.
 *
 * If all page follows the standard page layout, with a PageHeader and unused
 * space between pd_lower and pd_upper, set 'page_std' to true. That allows
 * the unused space to be left out from the WAL records, making them smaller.
 *
 * NOTE: This function acquires exclusive-locks on the pages. Typically, this
 * is used on a newly-built relation, and the caller is holding a
 * AccessExclusiveLock on it, so no other backend can be accessing it at the
 * same time. If that's not the case, you must ensure that this does not
 * cause a deadlock through some other means.
 */
void
log_newpage_range(Relation rel, ForkNumber forknum,
                  BlockNumber startblk, BlockNumber endblk,
                  bool page_std)
{
    int         flags;
    BlockNumber blkno;
 
    flags = REGBUF_FORCE_IMAGE;
    if (page_std)
        flags |= REGBUF_STANDARD;
 
    /*
     * Iterate over all the pages in the range. They are collected into
     * batches of XLR_MAX_BLOCK_ID pages, and a single WAL-record is written
     * for each batch.
     */
    XLogEnsureRecordSpace(XLR_MAX_BLOCK_ID - 1, 0);
 
    blkno = startblk;
    while (blkno < endblk)
    {
        Buffer      bufpack[XLR_MAX_BLOCK_ID];
        XLogRecPtr  recptr;
        int         nbufs;
        int         i;
 
        CHECK_FOR_INTERRUPTS();
 
        /* Collect a batch of blocks. */
        nbufs = 0;
        while (nbufs < XLR_MAX_BLOCK_ID && blkno < endblk)
        {
            Buffer      buf = ReadBufferExtended(rel, forknum, blkno,
                                                 RBM_NORMAL, NULL);
 
            LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
 
            /*
             * Completely empty pages are not WAL-logged. Writing a WAL record
             * would change the LSN, and we don't want that. We want the page
             * to stay empty.
             */
            if (!PageIsNew(BufferGetPage(buf)))
                bufpack[nbufs++] = buf;
            else
                UnlockReleaseBuffer(buf);
            blkno++;
        }
 
        /* Nothing more to do if all remaining blocks were empty. */
        if (nbufs == 0)
            break;
 
        /* Write WAL record for this batch. */
        XLogBeginInsert();
 
        START_CRIT_SECTION();
        for (i = 0; i < nbufs; i++)
        {
            MarkBufferDirty(bufpack[i]);
            XLogRegisterBuffer(i, bufpack[i], flags);
        }
 
        recptr = XLogInsert(RM_XLOG_ID, XLOG_FPI);
 
        for (i = 0; i < nbufs; i++)
        {
            PageSetLSN(BufferGetPage(bufpack[i]), recptr);
            UnlockReleaseBuffer(bufpack[i]);
        }
        END_CRIT_SECTION();
    }
}
 
/*
 * Allocate working buffers needed for WAL record construction.
 */
void
InitXLogInsert(void)
{
#ifdef USE_ASSERT_CHECKING
 
    /*
     * Check that any records assembled can be decoded.  This is capped based
     * on what XLogReader would require at its maximum bound.  The XLOG_BLCKSZ
     * addend covers the larger allocate_recordbuf() demand.  This code path
     * is called once per backend, more than enough for this check.
     */
    size_t      max_required =
        DecodeXLogRecordRequiredSpace(XLogRecordMaxSize + XLOG_BLCKSZ);
 
    Assert(AllocSizeIsValid(max_required));
#endif
 
    /* Initialize the working areas */
    if (xloginsert_cxt == NULL)
    {
        xloginsert_cxt = AllocSetContextCreate(TopMemoryContext,
                                               "WAL record construction",
                                               ALLOCSET_DEFAULT_SIZES);
    }
 
    if (registered_buffers == NULL)
    {
        registered_buffers = (registered_buffer *)
            MemoryContextAllocZero(xloginsert_cxt,
                                   sizeof(registered_buffer) * (XLR_NORMAL_MAX_BLOCK_ID + 1));
        max_registered_buffers = XLR_NORMAL_MAX_BLOCK_ID + 1;
    }
    if (rdatas == NULL)
    {
        rdatas = MemoryContextAlloc(xloginsert_cxt,
                                    sizeof(XLogRecData) * XLR_NORMAL_RDATAS);
        max_rdatas = XLR_NORMAL_RDATAS;
    }
 
    /*
     * Allocate a buffer to hold the header information for a WAL record.
     */
    if (hdr_scratch == NULL)
        hdr_scratch = MemoryContextAllocZero(xloginsert_cxt,
                                             HEADER_SCRATCH_SIZE);
}

◆ LZ4_MAX_BLCKSZ

#define LZ4_MAX_BLCKSZ 0

Definition at line 52 of file xloginsert.c.

◆ PGLZ_MAX_BLCKSZ

#define PGLZ_MAX_BLCKSZ PGLZ_MAX_OUTPUT(BLCKSZ)

Definition at line 61 of file xloginsert.c.

◆ SizeOfXlogOrigin

#define SizeOfXlogOrigin (sizeof(RepOriginId) + sizeof(char))

Definition at line 118 of file xloginsert.c.

◆ SizeOfXLogTransactionId

#define SizeOfXLogTransactionId (sizeof(TransactionId) + sizeof(char))

Definition at line 119 of file xloginsert.c.

◆ ZSTD_MAX_BLCKSZ

#define ZSTD_MAX_BLCKSZ 0

Definition at line 58 of file xloginsert.c.

Function Documentation

◆ InitXLogInsert()

void InitXLogInsert ( void )

Definition at line 1370 of file xloginsert.c.

{
#ifdef USE_ASSERT_CHECKING
 
    /*
     * Check that any records assembled can be decoded.  This is capped based
     * on what XLogReader would require at its maximum bound.  The XLOG_BLCKSZ
     * addend covers the larger allocate_recordbuf() demand.  This code path
     * is called once per backend, more than enough for this check.
     */
    size_t      max_required =
        DecodeXLogRecordRequiredSpace(XLogRecordMaxSize + XLOG_BLCKSZ);
 
    Assert(AllocSizeIsValid(max_required));
#endif
 
    /* Initialize the working areas */
    if (xloginsert_cxt == NULL)
    {
        xloginsert_cxt = AllocSetContextCreate(TopMemoryContext,
                                               "WAL record construction",
                                               ALLOCSET_DEFAULT_SIZES);
    }
 
    if (registered_buffers == NULL)
    {
        registered_buffers = (registered_buffer *)
            MemoryContextAllocZero(xloginsert_cxt,
                                   sizeof(registered_buffer) * (XLR_NORMAL_MAX_BLOCK_ID + 1));
        max_registered_buffers = XLR_NORMAL_MAX_BLOCK_ID + 1;
    }
    if (rdatas == NULL)
    {
        rdatas = MemoryContextAlloc(xloginsert_cxt,
                                    sizeof(XLogRecData) * XLR_NORMAL_RDATAS);
        max_rdatas = XLR_NORMAL_RDATAS;
    }
 
    /*
     * Allocate a buffer to hold the header information for a WAL record.
     */
    if (hdr_scratch == NULL)
        hdr_scratch = MemoryContextAllocZero(xloginsert_cxt,
                                             HEADER_SCRATCH_SIZE);
}

References ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate, AllocSizeIsValid, Assert, DecodeXLogRecordRequiredSpace(), fb(), hdr_scratch, HEADER_SCRATCH_SIZE, max_rdatas, max_registered_buffers, MemoryContextAlloc(), MemoryContextAllocZero(), rdatas, registered_buffers, TopMemoryContext, xloginsert_cxt, XLogRecordMaxSize, XLR_NORMAL_MAX_BLOCK_ID, and XLR_NORMAL_RDATAS.

Referenced by BaseInit().

◆ log_newpage()

XLogRecPtr log_newpage	(	RelFileLocator *	rlocator,
		ForkNumber	forknum,
		BlockNumber	blkno,
		Page	page,
		bool	page_std
	)

Definition at line 1165 of file xloginsert.c.

{
    int         flags;
    XLogRecPtr  recptr;
 
    flags = REGBUF_FORCE_IMAGE;
    if (page_std)
        flags |= REGBUF_STANDARD;
 
    XLogBeginInsert();
    XLogRegisterBlock(0, rlocator, forknum, blkno, page, flags);
    recptr = XLogInsert(RM_XLOG_ID, XLOG_FPI);
 
    /*
     * The page may be uninitialized. If so, we can't set the LSN because that
     * would corrupt the page.
     */
    if (!PageIsNew(page))
    {
        PageSetLSN(page, recptr);
    }
 
    return recptr;
}

References fb(), PageIsNew(), PageSetLSN(), REGBUF_FORCE_IMAGE, REGBUF_STANDARD, XLOG_FPI, XLogBeginInsert(), XLogInsert(), and XLogRegisterBlock().

Referenced by _hash_alloc_buckets(), _hash_init(), and log_newpage_buffer().

◆ log_newpage_buffer()

XLogRecPtr log_newpage_buffer	(	Buffer	buffer,
		bool	page_std
	)

Definition at line 1259 of file xloginsert.c.

{
    Page        page = BufferGetPage(buffer);
    RelFileLocator rlocator;
    ForkNumber  forknum;
    BlockNumber blkno;
 
    /* Shared buffers should be modified in a critical section. */
    Assert(CritSectionCount > 0);
 
    BufferGetTag(buffer, &rlocator, &forknum, &blkno);
 
    return log_newpage(&rlocator, forknum, blkno, page, page_std);
}

References Assert, BufferGetPage(), BufferGetTag(), CritSectionCount, and log_newpage().

Referenced by brin_initialize_empty_new_buffer(), brinbuildempty(), FreeSpaceMapPrepareTruncateRel(), ginbuildempty(), gistbuildempty(), heap_force_common(), lazy_scan_new_or_empty(), RelationCopyStorageUsingBuffer(), and visibilitymap_prepare_truncate().

◆ log_newpage_range()

void log_newpage_range	(	Relation	rel,
		ForkNumber	forknum,
		BlockNumber	startblk,
		BlockNumber	endblk,
		bool	page_std
	)

Definition at line 1292 of file xloginsert.c.

{
    int         flags;
    BlockNumber blkno;
 
    flags = REGBUF_FORCE_IMAGE;
    if (page_std)
        flags |= REGBUF_STANDARD;
 
    /*
     * Iterate over all the pages in the range. They are collected into
     * batches of XLR_MAX_BLOCK_ID pages, and a single WAL-record is written
     * for each batch.
     */
    XLogEnsureRecordSpace(XLR_MAX_BLOCK_ID - 1, 0);
 
    blkno = startblk;
    while (blkno < endblk)
    {
        Buffer      bufpack[XLR_MAX_BLOCK_ID];
        XLogRecPtr  recptr;
        int         nbufs;
        int         i;
 
        CHECK_FOR_INTERRUPTS();
 
        /* Collect a batch of blocks. */
        nbufs = 0;
        while (nbufs < XLR_MAX_BLOCK_ID && blkno < endblk)
        {
            Buffer      buf = ReadBufferExtended(rel, forknum, blkno,
                                                 RBM_NORMAL, NULL);
 
            LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
 
            /*
             * Completely empty pages are not WAL-logged. Writing a WAL record
             * would change the LSN, and we don't want that. We want the page
             * to stay empty.
             */
            if (!PageIsNew(BufferGetPage(buf)))
                bufpack[nbufs++] = buf;
            else
                UnlockReleaseBuffer(buf);
            blkno++;
        }
 
        /* Nothing more to do if all remaining blocks were empty. */
        if (nbufs == 0)
            break;
 
        /* Write WAL record for this batch. */
        XLogBeginInsert();
 
        START_CRIT_SECTION();
        for (i = 0; i < nbufs; i++)
        {
            MarkBufferDirty(bufpack[i]);
            XLogRegisterBuffer(i, bufpack[i], flags);
        }
 
        recptr = XLogInsert(RM_XLOG_ID, XLOG_FPI);
 
        for (i = 0; i < nbufs; i++)
        {
            PageSetLSN(BufferGetPage(bufpack[i]), recptr);
            UnlockReleaseBuffer(bufpack[i]);
        }
        END_CRIT_SECTION();
    }
}

References buf, BUFFER_LOCK_EXCLUSIVE, BufferGetPage(), CHECK_FOR_INTERRUPTS, END_CRIT_SECTION, fb(), i, LockBuffer(), MarkBufferDirty(), PageIsNew(), PageSetLSN(), RBM_NORMAL, ReadBufferExtended(), REGBUF_FORCE_IMAGE, REGBUF_STANDARD, START_CRIT_SECTION, UnlockReleaseBuffer(), XLOG_FPI, XLogBeginInsert(), XLogEnsureRecordSpace(), XLogInsert(), XLogRegisterBuffer(), and XLR_MAX_BLOCK_ID.

Referenced by ginbuild(), gistbuild(), smgrDoPendingSyncs(), and spgbuild().

◆ log_newpages()

void log_newpages	(	RelFileLocator *	rlocator,
		ForkNumber	forknum,
		int	num_pages,
		BlockNumber *	blknos,
		Page *	pages,
		bool	page_std
	)

Definition at line 1197 of file xloginsert.c.

{
    int         flags;
    XLogRecPtr  recptr;
    int         i;
    int         j;
 
    flags = REGBUF_FORCE_IMAGE;
    if (page_std)
        flags |= REGBUF_STANDARD;
 
    /*
     * Iterate over all the pages. They are collected into batches of
     * XLR_MAX_BLOCK_ID pages, and a single WAL-record is written for each
     * batch.
     */
    XLogEnsureRecordSpace(XLR_MAX_BLOCK_ID - 1, 0);
 
    i = 0;
    while (i < num_pages)
    {
        int         batch_start = i;
        int         nbatch;
 
        XLogBeginInsert();
 
        nbatch = 0;
        while (nbatch < XLR_MAX_BLOCK_ID && i < num_pages)
        {
            XLogRegisterBlock(nbatch, rlocator, forknum, blknos[i], pages[i], flags);
            i++;
            nbatch++;
        }
 
        recptr = XLogInsert(RM_XLOG_ID, XLOG_FPI);
 
        for (j = batch_start; j < i; j++)
        {
            /*
             * The page may be uninitialized. If so, we can't set the LSN
             * because that would corrupt the page.
             */
            if (!PageIsNew(pages[j]))
            {
                PageSetLSN(pages[j], recptr);
            }
        }
    }
}

References batch_start(), fb(), i, j, PageIsNew(), PageSetLSN(), REGBUF_FORCE_IMAGE, REGBUF_STANDARD, XLOG_FPI, XLogBeginInsert(), XLogEnsureRecordSpace(), XLogInsert(), XLogRegisterBlock(), and XLR_MAX_BLOCK_ID.

Referenced by smgr_bulk_flush().

◆ XLogBeginInsert()

void XLogBeginInsert ( void )

Definition at line 152 of file xloginsert.c.

{
    Assert(max_registered_block_id == 0);
    Assert(mainrdata_last == (XLogRecData *) &mainrdata_head);
    Assert(mainrdata_len == 0);
 
    /* cross-check on whether we should be here or not */
    if (!XLogInsertAllowed())
        elog(ERROR, "cannot make new WAL entries during recovery");
 
    if (begininsert_called)
        elog(ERROR, "XLogBeginInsert was already called");
 
    begininsert_called = true;
}

References Assert, begininsert_called, elog, ERROR, mainrdata_head, mainrdata_last, mainrdata_len, max_registered_block_id, and XLogInsertAllowed().

Referenced by _bt_allocbuf(), _bt_dedup_pass(), _bt_delitems_delete(), _bt_delitems_vacuum(), _bt_getroot(), _bt_insertonpg(), _bt_mark_page_halfdead(), _bt_newlevel(), _bt_set_cleanup_info(), _bt_split(), _bt_unlink_halfdead_page(), _hash_addovflpage(), _hash_doinsert(), _hash_expandtable(), _hash_freeovflpage(), _hash_init(), _hash_splitbucket(), _hash_squeezebucket(), _hash_vacuum_one_page(), addLeafTuple(), AssignTransactionId(), brin_doinsert(), brin_doupdate(), brinbuild(), brinRevmapDesummarizeRange(), CreateCheckPoint(), CreateDatabaseUsingFileCopy(), CreateDirAndVersionFile(), CreateEndOfRecoveryRecord(), CreateOverwriteContrecordRecord(), createPostingTree(), CreateTableSpace(), do_pg_backup_stop(), doPickSplit(), DropTableSpace(), EndPrepare(), ExecuteTruncateGuts(), fill_seq_fork_with_data(), GenericXLogFinish(), ginDeletePage(), ginHeapTupleFastInsert(), ginPlaceToPage(), ginUpdateStats(), ginVacuumPostingTreeLeaf(), gistXLogAssignLSN(), gistXLogDelete(), gistXLogPageDelete(), gistXLogPageReuse(), gistXLogSplit(), gistXLogUpdate(), hashbucketcleanup(), hashbulkdelete(), heap_abort_speculative(), heap_delete(), heap_finish_speculative(), heap_inplace_update_and_unlock(), heap_insert(), heap_lock_tuple(), heap_lock_updated_tuple_rec(), heap_multi_insert(), heap_update(), log_heap_new_cid(), log_heap_prune_and_freeze(), log_heap_update(), log_heap_visible(), log_newpage(), log_newpage_range(), log_newpages(), log_smgrcreate(), log_split_page(), LogAccessExclusiveLocks(), LogCurrentRunningXacts(), logical_heap_rewrite_flush_mappings(), LogLogicalInvalidations(), LogLogicalMessage(), LogStandbyInvalidations(), movedb(), moveLeafs(), MultiXactIdCreateFromMembers(), nextval_internal(), pg_truncate_visibility_map(), RelationTruncate(), remove_dbtablespaces(), replorigin_advance(), replorigin_state_clear(), RequestXLogSwitch(), revmap_physical_extend(), SetSequence(), shiftList(), spgAddNodeAction(), spgSplitNodeAction(), test_custom_rmgrs_insert_wal_record(), UpdateFullPageWrites(), vacuumLeafPage(), vacuumLeafRoot(), vacuumRedirectAndPlaceholder(), write_logical_decoding_status_update_record(), write_relmap_file(), writeListPage(), WriteMTruncateXlogRec(), WriteTruncateXlogRec(), WriteTruncateXlogRec(), XactLogAbortRecord(), XactLogCommitRecord(), XLogPutNextOid(), XLogReportParameters(), XLogRestorePoint(), XLogSaveBufferForHint(), XLogSimpleInsertInt64(), and xlogVacuumPage().

◆ XLogCheckBufferNeedsBackup()

bool XLogCheckBufferNeedsBackup ( Buffer buffer )

Definition at line 1049 of file xloginsert.c.

{
    XLogRecPtr  RedoRecPtr;
    bool        doPageWrites;
    Page        page;
 
    GetFullPageWriteInfo(&RedoRecPtr, &doPageWrites);
 
    page = BufferGetPage(buffer);
 
    if (doPageWrites && PageGetLSN(page) <= RedoRecPtr)
        return true;            /* buffer requires backup */
 
    return false;               /* buffer does not need to be backed up */
}

References BufferGetPage(), doPageWrites, GetFullPageWriteInfo(), PageGetLSN(), and RedoRecPtr.

Referenced by heap_page_will_freeze(), and log_heap_update().

◆ XLogCompressBackupBlock()

static bool XLogCompressBackupBlock	(	const PageData *	page,
		uint16	hole_offset,
		uint16	hole_length,
		void *	dest,
		uint16 *	dlen
	)

static

Definition at line 966 of file xloginsert.c.

{
    int32       orig_len = BLCKSZ - hole_length;
    int32       len = -1;
    int32       extra_bytes = 0;
    const void *source;
    PGAlignedBlock tmp;
 
    if (hole_length != 0)
    {
        /* must skip the hole */
        memcpy(tmp.data, page, hole_offset);
        memcpy(tmp.data + hole_offset,
               page + (hole_offset + hole_length),
               BLCKSZ - (hole_length + hole_offset));
        source = tmp.data;
 
        /*
         * Extra data needs to be stored in WAL record for the compressed
         * version of block image if the hole exists.
         */
        extra_bytes = SizeOfXLogRecordBlockCompressHeader;
    }
    else
        source = page;
 
    switch ((WalCompression) wal_compression)
    {
        case WAL_COMPRESSION_PGLZ:
            len = pglz_compress(source, orig_len, dest, PGLZ_strategy_default);
            break;
 
        case WAL_COMPRESSION_LZ4:
#ifdef USE_LZ4
            len = LZ4_compress_default(source, dest, orig_len,
                                       COMPRESS_BUFSIZE);
            if (len <= 0)
                len = -1;       /* failure */
#else
            elog(ERROR, "LZ4 is not supported by this build");
#endif
            break;
 
        case WAL_COMPRESSION_ZSTD:
#ifdef USE_ZSTD
            len = ZSTD_compress(dest, COMPRESS_BUFSIZE, source, orig_len,
                                ZSTD_CLEVEL_DEFAULT);
            if (ZSTD_isError(len))
                len = -1;       /* failure */
#else
            elog(ERROR, "zstd is not supported by this build");
#endif
            break;
 
        case WAL_COMPRESSION_NONE:
            Assert(false);      /* cannot happen */
            break;
            /* no default case, so that compiler will warn */
    }
 
    /*
     * We recheck the actual size even if compression reports success and see
     * if the number of bytes saved by compression is larger than the length
     * of extra data needed for the compressed version of block image.
     */
    if (len >= 0 &&
        len + extra_bytes < orig_len)
    {
        *dlen = (uint16) len;   /* successful compression */
        return true;
    }
    return false;
}

References Assert, COMPRESS_BUFSIZE, PGAlignedBlock::data, elog, ERROR, fb(), len, pglz_compress(), PGLZ_strategy_default, SizeOfXLogRecordBlockCompressHeader, source, wal_compression, WAL_COMPRESSION_LZ4, WAL_COMPRESSION_NONE, WAL_COMPRESSION_PGLZ, and WAL_COMPRESSION_ZSTD.

Referenced by XLogRecordAssemble().

◆ XLogEnsureRecordSpace()

void XLogEnsureRecordSpace	(	int	max_block_id,
		int	ndatas
	)

Definition at line 178 of file xloginsert.c.

{
    int         nbuffers;
 
    /*
     * This must be called before entering a critical section, because
     * allocating memory inside a critical section can fail. repalloc() will
     * check the same, but better to check it here too so that we fail
     * consistently even if the arrays happen to be large enough already.
     */
    Assert(CritSectionCount == 0);
 
    /* the minimum values can't be decreased */
    if (max_block_id < XLR_NORMAL_MAX_BLOCK_ID)
        max_block_id = XLR_NORMAL_MAX_BLOCK_ID;
    if (ndatas < XLR_NORMAL_RDATAS)
        ndatas = XLR_NORMAL_RDATAS;
 
    if (max_block_id > XLR_MAX_BLOCK_ID)
        elog(ERROR, "maximum number of WAL record block references exceeded");
    nbuffers = max_block_id + 1;
 
    if (nbuffers > max_registered_buffers)
    {
        registered_buffers = (registered_buffer *)
            repalloc(registered_buffers, sizeof(registered_buffer) * nbuffers);
 
        /*
         * At least the padding bytes in the structs must be zeroed, because
         * they are included in WAL data, but initialize it all for tidiness.
         */
        MemSet(&registered_buffers[max_registered_buffers], 0,
               (nbuffers - max_registered_buffers) * sizeof(registered_buffer));
        max_registered_buffers = nbuffers;
    }
 
    if (ndatas > max_rdatas)
    {
        rdatas = (XLogRecData *) repalloc(rdatas, sizeof(XLogRecData) * ndatas);
        max_rdatas = ndatas;
    }
}

References Assert, CritSectionCount, elog, ERROR, fb(), max_rdatas, max_registered_buffers, MemSet, rdatas, registered_buffers, repalloc(), XLR_MAX_BLOCK_ID, XLR_NORMAL_MAX_BLOCK_ID, and XLR_NORMAL_RDATAS.

Referenced by _hash_freeovflpage(), _hash_squeezebucket(), EndPrepare(), gistplacetopage(), log_newpage_range(), log_newpages(), and shiftList().

◆ XLogInsert()

XLogRecPtr XLogInsert	(	RmgrId	rmid,
		uint8	info
	)

Definition at line 478 of file xloginsert.c.

{
    XLogRecPtr  EndPos;
 
    /* XLogBeginInsert() must have been called. */
    if (!begininsert_called)
        elog(ERROR, "XLogBeginInsert was not called");
 
    /*
     * The caller can set rmgr bits, XLR_SPECIAL_REL_UPDATE and
     * XLR_CHECK_CONSISTENCY; the rest are reserved for use by me.
     */
    if ((info & ~(XLR_RMGR_INFO_MASK |
                  XLR_SPECIAL_REL_UPDATE |
                  XLR_CHECK_CONSISTENCY)) != 0)
        elog(PANIC, "invalid xlog info mask %02X", info);
 
    TRACE_POSTGRESQL_WAL_INSERT(rmid, info);
 
    /*
     * In bootstrap mode, we don't actually log anything but XLOG resources;
     * return a phony record pointer.
     */
    if (IsBootstrapProcessingMode() && rmid != RM_XLOG_ID)
    {
        XLogResetInsertion();
        EndPos = SizeOfXLogLongPHD; /* start of 1st chkpt record */
        return EndPos;
    }
 
    do
    {
        XLogRecPtr  RedoRecPtr;
        bool        doPageWrites;
        bool        topxid_included = false;
        XLogRecPtr  fpw_lsn;
        XLogRecData *rdt;
        int         num_fpi = 0;
        uint64      fpi_bytes = 0;
 
        /*
         * Get values needed to decide whether to do full-page writes. Since
         * we don't yet have an insertion lock, these could change under us,
         * but XLogInsertRecord will recheck them once it has a lock.
         */
        GetFullPageWriteInfo(&RedoRecPtr, &doPageWrites);
 
        rdt = XLogRecordAssemble(rmid, info, RedoRecPtr, doPageWrites,
                                 &fpw_lsn, &num_fpi, &fpi_bytes,
                                 &topxid_included);
 
        EndPos = XLogInsertRecord(rdt, fpw_lsn, curinsert_flags, num_fpi,
                                  fpi_bytes, topxid_included);
    } while (!XLogRecPtrIsValid(EndPos));
 
    XLogResetInsertion();
 
    return EndPos;
}

References begininsert_called, curinsert_flags, doPageWrites, elog, ERROR, fb(), GetFullPageWriteInfo(), IsBootstrapProcessingMode, PANIC, RedoRecPtr, SizeOfXLogLongPHD, XLogInsertRecord(), XLogRecordAssemble(), XLogRecPtrIsValid, XLogResetInsertion(), XLR_CHECK_CONSISTENCY, XLR_RMGR_INFO_MASK, and XLR_SPECIAL_REL_UPDATE.

Referenced by _bt_allocbuf(), _bt_dedup_pass(), _bt_delitems_delete(), _bt_delitems_vacuum(), _bt_getroot(), _bt_insertonpg(), _bt_mark_page_halfdead(), _bt_newlevel(), _bt_set_cleanup_info(), _bt_split(), _bt_unlink_halfdead_page(), _hash_addovflpage(), _hash_doinsert(), _hash_expandtable(), _hash_freeovflpage(), _hash_init(), _hash_splitbucket(), _hash_squeezebucket(), _hash_vacuum_one_page(), addLeafTuple(), AssignTransactionId(), brin_doinsert(), brin_doupdate(), brinbuild(), brinRevmapDesummarizeRange(), CreateCheckPoint(), CreateDatabaseUsingFileCopy(), CreateDirAndVersionFile(), CreateEndOfRecoveryRecord(), CreateOverwriteContrecordRecord(), createPostingTree(), CreateTableSpace(), do_pg_backup_stop(), doPickSplit(), DropTableSpace(), EndPrepare(), ExecuteTruncateGuts(), fill_seq_fork_with_data(), GenericXLogFinish(), ginDeletePage(), ginHeapTupleFastInsert(), ginPlaceToPage(), ginUpdateStats(), ginVacuumPostingTreeLeaf(), gistXLogAssignLSN(), gistXLogDelete(), gistXLogPageDelete(), gistXLogPageReuse(), gistXLogSplit(), gistXLogUpdate(), hashbucketcleanup(), hashbulkdelete(), heap_abort_speculative(), heap_delete(), heap_finish_speculative(), heap_inplace_update_and_unlock(), heap_insert(), heap_lock_tuple(), heap_lock_updated_tuple_rec(), heap_multi_insert(), heap_update(), log_heap_new_cid(), log_heap_prune_and_freeze(), log_heap_update(), log_heap_visible(), log_newpage(), log_newpage_range(), log_newpages(), log_smgrcreate(), log_split_page(), LogAccessExclusiveLocks(), LogCurrentRunningXacts(), logical_heap_rewrite_flush_mappings(), LogLogicalInvalidations(), LogLogicalMessage(), LogStandbyInvalidations(), movedb(), moveLeafs(), MultiXactIdCreateFromMembers(), nextval_internal(), pg_truncate_visibility_map(), RelationTruncate(), remove_dbtablespaces(), replorigin_advance(), replorigin_state_clear(), RequestXLogSwitch(), revmap_physical_extend(), SetSequence(), shiftList(), spgAddNodeAction(), spgSplitNodeAction(), test_custom_rmgrs_insert_wal_record(), UpdateFullPageWrites(), vacuumLeafPage(), vacuumLeafRoot(), vacuumRedirectAndPlaceholder(), write_logical_decoding_status_update_record(), write_relmap_file(), writeListPage(), WriteMTruncateXlogRec(), WriteTruncateXlogRec(), WriteTruncateXlogRec(), XactLogAbortRecord(), XactLogCommitRecord(), XLogPutNextOid(), XLogReportParameters(), XLogRestorePoint(), XLogSaveBufferForHint(), XLogSimpleInsertInt64(), and xlogVacuumPage().

◆ XLogRecordAssemble()

static XLogRecData * XLogRecordAssemble	(	RmgrId	rmid,
		uint8	info,
		XLogRecPtr	RedoRecPtr,
		bool	doPageWrites,
		XLogRecPtr *	fpw_lsn,
		int *	num_fpi,
		uint64 *	fpi_bytes,
		bool *	topxid_included
	)

static

Definition at line 566 of file xloginsert.c.

{
    XLogRecData *rdt;
    uint64      total_len = 0;
    int         block_id;
    pg_crc32c   rdata_crc;
    registered_buffer *prev_regbuf = NULL;
    XLogRecData *rdt_datas_last;
    XLogRecord *rechdr;
    char       *scratch = hdr_scratch;
 
    /*
     * Note: this function can be called multiple times for the same record.
     * All the modifications we do to the rdata chains below must handle that.
     */
 
    /* The record begins with the fixed-size header */
    rechdr = (XLogRecord *) scratch;
    scratch += SizeOfXLogRecord;
 
    hdr_rdt.next = NULL;
    rdt_datas_last = &hdr_rdt;
    hdr_rdt.data = hdr_scratch;
 
    /*
     * Enforce consistency checks for this record if user is looking for it.
     * Do this before at the beginning of this routine to give the possibility
     * for callers of XLogInsert() to pass XLR_CHECK_CONSISTENCY directly for
     * a record.
     */
    if (wal_consistency_checking[rmid])
        info |= XLR_CHECK_CONSISTENCY;
 
    /*
     * Make an rdata chain containing all the data portions of all block
     * references. This includes the data for full-page images. Also append
     * the headers for the block references in the scratch buffer.
     */
    *fpw_lsn = InvalidXLogRecPtr;
    for (block_id = 0; block_id < max_registered_block_id; block_id++)
    {
        registered_buffer *regbuf = &registered_buffers[block_id];
        bool        needs_backup;
        bool        needs_data;
        XLogRecordBlockHeader bkpb;
        XLogRecordBlockImageHeader bimg;
        XLogRecordBlockCompressHeader cbimg = {0};
        bool        samerel;
        bool        is_compressed = false;
        bool        include_image;
 
        if (!regbuf->in_use)
            continue;
 
        /* Determine if this block needs to be backed up */
        if (regbuf->flags & REGBUF_FORCE_IMAGE)
            needs_backup = true;
        else if (regbuf->flags & REGBUF_NO_IMAGE)
            needs_backup = false;
        else if (!doPageWrites)
            needs_backup = false;
        else
        {
            /*
             * We assume page LSN is first data on *every* page that can be
             * passed to XLogInsert, whether it has the standard page layout
             * or not.
             */
            XLogRecPtr  page_lsn = PageGetLSN(regbuf->page);
 
            needs_backup = (page_lsn <= RedoRecPtr);
            if (!needs_backup)
            {
                if (!XLogRecPtrIsValid(*fpw_lsn) || page_lsn < *fpw_lsn)
                    *fpw_lsn = page_lsn;
            }
        }
 
        /* Determine if the buffer data needs to included */
        if (regbuf->rdata_len == 0)
            needs_data = false;
        else if ((regbuf->flags & REGBUF_KEEP_DATA) != 0)
            needs_data = true;
        else
            needs_data = !needs_backup;
 
        bkpb.id = block_id;
        bkpb.fork_flags = regbuf->forkno;
        bkpb.data_length = 0;
 
        if ((regbuf->flags & REGBUF_WILL_INIT) == REGBUF_WILL_INIT)
            bkpb.fork_flags |= BKPBLOCK_WILL_INIT;
 
        /*
         * If needs_backup is true or WAL checking is enabled for current
         * resource manager, log a full-page write for the current block.
         */
        include_image = needs_backup || (info & XLR_CHECK_CONSISTENCY) != 0;
 
        if (include_image)
        {
            const PageData *page = regbuf->page;
            uint16      compressed_len = 0;
 
            /*
             * The page needs to be backed up, so calculate its hole length
             * and offset.
             */
            if (regbuf->flags & REGBUF_STANDARD)
            {
                /* Assume we can omit data between pd_lower and pd_upper */
                uint16      lower = ((PageHeader) page)->pd_lower;
                uint16      upper = ((PageHeader) page)->pd_upper;
 
                if (lower >= SizeOfPageHeaderData &&
                    upper > lower &&
                    upper <= BLCKSZ)
                {
                    bimg.hole_offset = lower;
                    cbimg.hole_length = upper - lower;
                }
                else
                {
                    /* No "hole" to remove */
                    bimg.hole_offset = 0;
                    cbimg.hole_length = 0;
                }
            }
            else
            {
                /* Not a standard page header, don't try to eliminate "hole" */
                bimg.hole_offset = 0;
                cbimg.hole_length = 0;
            }
 
            /*
             * Try to compress a block image if wal_compression is enabled
             */
            if (wal_compression != WAL_COMPRESSION_NONE)
            {
                is_compressed =
                    XLogCompressBackupBlock(page, bimg.hole_offset,
                                            cbimg.hole_length,
                                            regbuf->compressed_page,
                                            &compressed_len);
            }
 
            /*
             * Fill in the remaining fields in the XLogRecordBlockHeader
             * struct
             */
            bkpb.fork_flags |= BKPBLOCK_HAS_IMAGE;
 
            /* Report a full page image constructed for the WAL record */
            *num_fpi += 1;
 
            /*
             * Construct XLogRecData entries for the page content.
             */
            rdt_datas_last->next = &regbuf->bkp_rdatas[0];
            rdt_datas_last = rdt_datas_last->next;
 
            bimg.bimg_info = (cbimg.hole_length == 0) ? 0 : BKPIMAGE_HAS_HOLE;
 
            /*
             * If WAL consistency checking is enabled for the resource manager
             * of this WAL record, a full-page image is included in the record
             * for the block modified. During redo, the full-page is replayed
             * only if BKPIMAGE_APPLY is set.
             */
            if (needs_backup)
                bimg.bimg_info |= BKPIMAGE_APPLY;
 
            if (is_compressed)
            {
                /* The current compression is stored in the WAL record */
                bimg.length = compressed_len;
 
                /* Set the compression method used for this block */
                switch ((WalCompression) wal_compression)
                {
                    case WAL_COMPRESSION_PGLZ:
                        bimg.bimg_info |= BKPIMAGE_COMPRESS_PGLZ;
                        break;
 
                    case WAL_COMPRESSION_LZ4:
#ifdef USE_LZ4
                        bimg.bimg_info |= BKPIMAGE_COMPRESS_LZ4;
#else
                        elog(ERROR, "LZ4 is not supported by this build");
#endif
                        break;
 
                    case WAL_COMPRESSION_ZSTD:
#ifdef USE_ZSTD
                        bimg.bimg_info |= BKPIMAGE_COMPRESS_ZSTD;
#else
                        elog(ERROR, "zstd is not supported by this build");
#endif
                        break;
 
                    case WAL_COMPRESSION_NONE:
                        Assert(false);  /* cannot happen */
                        break;
                        /* no default case, so that compiler will warn */
                }
 
                rdt_datas_last->data = regbuf->compressed_page;
                rdt_datas_last->len = compressed_len;
            }
            else
            {
                bimg.length = BLCKSZ - cbimg.hole_length;
 
                if (cbimg.hole_length == 0)
                {
                    rdt_datas_last->data = page;
                    rdt_datas_last->len = BLCKSZ;
                }
                else
                {
                    /* must skip the hole */
                    rdt_datas_last->data = page;
                    rdt_datas_last->len = bimg.hole_offset;
 
                    rdt_datas_last->next = &regbuf->bkp_rdatas[1];
                    rdt_datas_last = rdt_datas_last->next;
 
                    rdt_datas_last->data =
                        page + (bimg.hole_offset + cbimg.hole_length);
                    rdt_datas_last->len =
                        BLCKSZ - (bimg.hole_offset + cbimg.hole_length);
                }
            }
 
            total_len += bimg.length;
 
            /* Track the WAL full page images in bytes */
            *fpi_bytes += bimg.length;
        }
 
        if (needs_data)
        {
            /*
             * When copying to XLogRecordBlockHeader, the length is narrowed
             * to an uint16.  Double-check that it is still correct.
             */
            Assert(regbuf->rdata_len <= UINT16_MAX);
 
            /*
             * Link the caller-supplied rdata chain for this buffer to the
             * overall list.
             */
            bkpb.fork_flags |= BKPBLOCK_HAS_DATA;
            bkpb.data_length = (uint16) regbuf->rdata_len;
            total_len += regbuf->rdata_len;
 
            rdt_datas_last->next = regbuf->rdata_head;
            rdt_datas_last = regbuf->rdata_tail;
        }
 
        if (prev_regbuf && RelFileLocatorEquals(regbuf->rlocator, prev_regbuf->rlocator))
        {
            samerel = true;
            bkpb.fork_flags |= BKPBLOCK_SAME_REL;
        }
        else
            samerel = false;
        prev_regbuf = regbuf;
 
        /* Ok, copy the header to the scratch buffer */
        memcpy(scratch, &bkpb, SizeOfXLogRecordBlockHeader);
        scratch += SizeOfXLogRecordBlockHeader;
        if (include_image)
        {
            memcpy(scratch, &bimg, SizeOfXLogRecordBlockImageHeader);
            scratch += SizeOfXLogRecordBlockImageHeader;
            if (cbimg.hole_length != 0 && is_compressed)
            {
                memcpy(scratch, &cbimg,
                       SizeOfXLogRecordBlockCompressHeader);
                scratch += SizeOfXLogRecordBlockCompressHeader;
            }
        }
        if (!samerel)
        {
            memcpy(scratch, &regbuf->rlocator, sizeof(RelFileLocator));
            scratch += sizeof(RelFileLocator);
        }
        memcpy(scratch, &regbuf->block, sizeof(BlockNumber));
        scratch += sizeof(BlockNumber);
    }
 
    /* followed by the record's origin, if any */
    if ((curinsert_flags & XLOG_INCLUDE_ORIGIN) &&
        replorigin_session_origin != InvalidRepOriginId)
    {
        *(scratch++) = (char) XLR_BLOCK_ID_ORIGIN;
        memcpy(scratch, &replorigin_session_origin, sizeof(replorigin_session_origin));
        scratch += sizeof(replorigin_session_origin);
    }
 
    /* followed by toplevel XID, if not already included in previous record */
    if (IsSubxactTopXidLogPending())
    {
        TransactionId xid = GetTopTransactionIdIfAny();
 
        /* Set the flag that the top xid is included in the WAL */
        *topxid_included = true;
 
        *(scratch++) = (char) XLR_BLOCK_ID_TOPLEVEL_XID;
        memcpy(scratch, &xid, sizeof(TransactionId));
        scratch += sizeof(TransactionId);
    }
 
    /* followed by main data, if any */
    if (mainrdata_len > 0)
    {
        if (mainrdata_len > 255)
        {
            uint32      mainrdata_len_4b;
 
            if (mainrdata_len > PG_UINT32_MAX)
                ereport(ERROR,
                        (errmsg_internal("too much WAL data"),
                         errdetail_internal("Main data length is %" PRIu64 " bytes for a maximum of %u bytes.",
                                            mainrdata_len,
                                            PG_UINT32_MAX)));
 
            mainrdata_len_4b = (uint32) mainrdata_len;
            *(scratch++) = (char) XLR_BLOCK_ID_DATA_LONG;
            memcpy(scratch, &mainrdata_len_4b, sizeof(uint32));
            scratch += sizeof(uint32);
        }
        else
        {
            *(scratch++) = (char) XLR_BLOCK_ID_DATA_SHORT;
            *(scratch++) = (uint8) mainrdata_len;
        }
        rdt_datas_last->next = mainrdata_head;
        rdt_datas_last = mainrdata_last;
        total_len += mainrdata_len;
    }
    rdt_datas_last->next = NULL;
 
    hdr_rdt.len = (scratch - hdr_scratch);
    total_len += hdr_rdt.len;
 
    /*
     * Calculate CRC of the data
     *
     * Note that the record header isn't added into the CRC initially since we
     * don't know the prev-link yet.  Thus, the CRC will represent the CRC of
     * the whole record in the order: rdata, then backup blocks, then record
     * header.
     */
    INIT_CRC32C(rdata_crc);
    COMP_CRC32C(rdata_crc, hdr_scratch + SizeOfXLogRecord, hdr_rdt.len - SizeOfXLogRecord);
    for (rdt = hdr_rdt.next; rdt != NULL; rdt = rdt->next)
        COMP_CRC32C(rdata_crc, rdt->data, rdt->len);
 
    /*
     * Ensure that the XLogRecord is not too large.
     *
     * XLogReader machinery is only able to handle records up to a certain
     * size (ignoring machine resource limitations), so make sure that we will
     * not emit records larger than the sizes advertised to be supported.
     */
    if (total_len > XLogRecordMaxSize)
        ereport(ERROR,
                (errmsg_internal("oversized WAL record"),
                 errdetail_internal("WAL record would be %" PRIu64 " bytes (of maximum %u bytes); rmid %u flags %u.",
                                    total_len, XLogRecordMaxSize, rmid, info)));
 
    /*
     * Fill in the fields in the record header. Prev-link is filled in later,
     * once we know where in the WAL the record will be inserted. The CRC does
     * not include the record header yet.
     */
    rechdr->xl_xid = GetCurrentTransactionIdIfAny();
    rechdr->xl_tot_len = (uint32) total_len;
    rechdr->xl_info = info;
    rechdr->xl_rmid = rmid;
    rechdr->xl_prev = InvalidXLogRecPtr;
    rechdr->xl_crc = rdata_crc;
 
    return &hdr_rdt;
}

References Assert, BKPBLOCK_HAS_DATA, BKPBLOCK_HAS_IMAGE, BKPBLOCK_SAME_REL, BKPBLOCK_WILL_INIT, BKPIMAGE_APPLY, BKPIMAGE_COMPRESS_LZ4, BKPIMAGE_COMPRESS_PGLZ, BKPIMAGE_COMPRESS_ZSTD, BKPIMAGE_HAS_HOLE, COMP_CRC32C, curinsert_flags, XLogRecData::data, doPageWrites, elog, ereport, errdetail_internal(), errmsg_internal(), ERROR, fb(), GetCurrentTransactionIdIfAny(), GetTopTransactionIdIfAny(), hdr_rdt, hdr_scratch, INIT_CRC32C, InvalidRepOriginId, InvalidXLogRecPtr, IsSubxactTopXidLogPending(), XLogRecData::len, lower(), mainrdata_head, mainrdata_last, mainrdata_len, max_registered_block_id, XLogRecData::next, PageGetLSN(), PG_UINT32_MAX, RedoRecPtr, REGBUF_FORCE_IMAGE, REGBUF_KEEP_DATA, REGBUF_NO_IMAGE, REGBUF_STANDARD, REGBUF_WILL_INIT, registered_buffers, RelFileLocatorEquals, replorigin_session_origin, SizeOfPageHeaderData, SizeOfXLogRecord, SizeOfXLogRecordBlockCompressHeader, SizeOfXLogRecordBlockHeader, SizeOfXLogRecordBlockImageHeader, upper(), wal_compression, WAL_COMPRESSION_LZ4, WAL_COMPRESSION_NONE, WAL_COMPRESSION_PGLZ, WAL_COMPRESSION_ZSTD, wal_consistency_checking, XLOG_INCLUDE_ORIGIN, XLogCompressBackupBlock(), XLogRecordMaxSize, XLogRecPtrIsValid, XLR_BLOCK_ID_DATA_LONG, XLR_BLOCK_ID_DATA_SHORT, XLR_BLOCK_ID_ORIGIN, XLR_BLOCK_ID_TOPLEVEL_XID, and XLR_CHECK_CONSISTENCY.

Referenced by XLogInsert().

◆ XLogRegisterBlock()

void XLogRegisterBlock	(	uint8	block_id,
		RelFileLocator *	rlocator,
		ForkNumber	forknum,
		BlockNumber	blknum,
		const PageData *	page,
		uint8	flags
	)

Definition at line 313 of file xloginsert.c.

{
    registered_buffer *regbuf;
 
    Assert(begininsert_called);
 
    if (block_id >= max_registered_block_id)
        max_registered_block_id = block_id + 1;
 
    if (block_id >= max_registered_buffers)
        elog(ERROR, "too many registered buffers");
 
    regbuf = &registered_buffers[block_id];
 
    regbuf->rlocator = *rlocator;
    regbuf->forkno = forknum;
    regbuf->block = blknum;
    regbuf->page = page;
    regbuf->flags = flags;
    regbuf->rdata_tail = (XLogRecData *) &regbuf->rdata_head;
    regbuf->rdata_len = 0;
 
    /*
     * Check that this page hasn't already been registered with some other
     * block_id.
     */
#ifdef USE_ASSERT_CHECKING
    {
        int         i;
 
        for (i = 0; i < max_registered_block_id; i++)
        {
            registered_buffer *regbuf_old = &registered_buffers[i];
 
            if (i == block_id || !regbuf_old->in_use)
                continue;
 
            Assert(!RelFileLocatorEquals(regbuf_old->rlocator, regbuf->rlocator) ||
                   regbuf_old->forkno != regbuf->forkno ||
                   regbuf_old->block != regbuf->block);
        }
    }
#endif
 
    regbuf->in_use = true;
}

References Assert, begininsert_called, elog, ERROR, fb(), i, max_registered_block_id, max_registered_buffers, registered_buffers, RelFileLocatorEquals, and registered_buffer::rlocator.

Referenced by heap_inplace_update_and_unlock(), log_newpage(), log_newpages(), and XLogSaveBufferForHint().

◆ XLogRegisterBufData()

void XLogRegisterBufData	(	uint8	block_id,
		const void *	data,
		uint32	len
	)

Definition at line 409 of file xloginsert.c.

{
    registered_buffer *regbuf;
    XLogRecData *rdata;
 
    Assert(begininsert_called);
 
    /* find the registered buffer struct */
    regbuf = &registered_buffers[block_id];
    if (!regbuf->in_use)
        elog(ERROR, "no block with id %d registered with WAL insertion",
             block_id);
 
    /*
     * Check against max_rdatas and ensure we do not register more data per
     * buffer than can be handled by the physical data format; i.e. that
     * regbuf->rdata_len does not grow beyond what
     * XLogRecordBlockHeader->data_length can hold.
     */
    if (num_rdatas >= max_rdatas)
        ereport(ERROR,
                (errmsg_internal("too much WAL data"),
                 errdetail_internal("%d out of %d data segments are already in use.",
                                    num_rdatas, max_rdatas)));
    if (regbuf->rdata_len + len > UINT16_MAX || len > UINT16_MAX)
        ereport(ERROR,
                (errmsg_internal("too much WAL data"),
                 errdetail_internal("Registering more than maximum %u bytes allowed to block %u: current %u bytes, adding %u bytes.",
                                    UINT16_MAX, block_id, regbuf->rdata_len, len)));
 
    rdata = &rdatas[num_rdatas++];
 
    rdata->data = data;
    rdata->len = len;
 
    regbuf->rdata_tail->next = rdata;
    regbuf->rdata_tail = rdata;
    regbuf->rdata_len += len;
}

References Assert, begininsert_called, XLogRecData::data, data, elog, ereport, errdetail_internal(), errmsg_internal(), ERROR, fb(), len, max_rdatas, num_rdatas, rdatas, and registered_buffers.

Referenced by _bt_dedup_pass(), _bt_delitems_delete(), _bt_delitems_vacuum(), _bt_getroot(), _bt_insertonpg(), _bt_newlevel(), _bt_set_cleanup_info(), _bt_split(), _bt_unlink_halfdead_page(), _hash_addovflpage(), _hash_doinsert(), _hash_expandtable(), _hash_freeovflpage(), _hash_squeezebucket(), brin_doinsert(), brin_doupdate(), dataExecPlaceToPageInternal(), dataExecPlaceToPageLeaf(), entryExecPlaceToPage(), GenericXLogFinish(), ginHeapTupleFastInsert(), ginVacuumPostingTreeLeaf(), gistXLogSplit(), gistXLogUpdate(), hashbucketcleanup(), heap_inplace_update_and_unlock(), heap_insert(), heap_multi_insert(), log_heap_prune_and_freeze(), log_heap_update(), and writeListPage().

◆ XLogRegisterBuffer()

void XLogRegisterBuffer	(	uint8	block_id,
		Buffer	buffer,
		uint8	flags
	)

Definition at line 245 of file xloginsert.c.

{
    registered_buffer *regbuf;
 
    /* NO_IMAGE doesn't make sense with FORCE_IMAGE */
    Assert(!((flags & REGBUF_FORCE_IMAGE) && (flags & (REGBUF_NO_IMAGE))));
    Assert(begininsert_called);
 
    /*
     * Ordinarily, buffer should be exclusive-locked and marked dirty before
     * we get here, otherwise we could end up violating one of the rules in
     * access/transam/README.
     *
     * Some callers intentionally register a clean page and never update that
     * page's LSN; in that case they can pass the flag REGBUF_NO_CHANGE to
     * bypass these checks.
     */
#ifdef USE_ASSERT_CHECKING
    if (!(flags & REGBUF_NO_CHANGE))
        Assert(BufferIsLockedByMeInMode(buffer, BUFFER_LOCK_EXCLUSIVE) &&
               BufferIsDirty(buffer));
#endif
 
    if (block_id >= max_registered_block_id)
    {
        if (block_id >= max_registered_buffers)
            elog(ERROR, "too many registered buffers");
        max_registered_block_id = block_id + 1;
    }
 
    regbuf = &registered_buffers[block_id];
 
    BufferGetTag(buffer, &regbuf->rlocator, &regbuf->forkno, &regbuf->block);
    regbuf->page = BufferGetPage(buffer);
    regbuf->flags = flags;
    regbuf->rdata_tail = (XLogRecData *) &regbuf->rdata_head;
    regbuf->rdata_len = 0;
 
    /*
     * Check that this page hasn't already been registered with some other
     * block_id.
     */
#ifdef USE_ASSERT_CHECKING
    {
        int         i;
 
        for (i = 0; i < max_registered_block_id; i++)
        {
            registered_buffer *regbuf_old = &registered_buffers[i];
 
            if (i == block_id || !regbuf_old->in_use)
                continue;
 
            Assert(!RelFileLocatorEquals(regbuf_old->rlocator, regbuf->rlocator) ||
                   regbuf_old->forkno != regbuf->forkno ||
                   regbuf_old->block != regbuf->block);
        }
    }
#endif
 
    regbuf->in_use = true;
}

References Assert, begininsert_called, BUFFER_LOCK_EXCLUSIVE, BufferGetPage(), BufferGetTag(), BufferIsDirty(), BufferIsLockedByMeInMode(), elog, ERROR, fb(), i, max_registered_block_id, max_registered_buffers, REGBUF_FORCE_IMAGE, REGBUF_NO_CHANGE, REGBUF_NO_IMAGE, registered_buffers, and RelFileLocatorEquals.

Referenced by _bt_dedup_pass(), _bt_delitems_delete(), _bt_delitems_vacuum(), _bt_getroot(), _bt_insertonpg(), _bt_mark_page_halfdead(), _bt_newlevel(), _bt_set_cleanup_info(), _bt_split(), _bt_unlink_halfdead_page(), _hash_addovflpage(), _hash_doinsert(), _hash_expandtable(), _hash_freeovflpage(), _hash_init(), _hash_splitbucket(), _hash_squeezebucket(), _hash_vacuum_one_page(), addLeafTuple(), brin_doinsert(), brin_doupdate(), brinbuild(), brinRevmapDesummarizeRange(), createPostingTree(), dataExecPlaceToPageInternal(), dataExecPlaceToPageLeaf(), doPickSplit(), entryExecPlaceToPage(), fill_seq_fork_with_data(), GenericXLogFinish(), ginDeletePage(), ginHeapTupleFastInsert(), ginPlaceToPage(), ginUpdateStats(), ginVacuumPostingTreeLeaf(), gistXLogDelete(), gistXLogPageDelete(), gistXLogSplit(), gistXLogUpdate(), hashbucketcleanup(), hashbulkdelete(), heap_abort_speculative(), heap_delete(), heap_finish_speculative(), heap_insert(), heap_lock_tuple(), heap_lock_updated_tuple_rec(), heap_multi_insert(), heap_update(), log_heap_prune_and_freeze(), log_heap_update(), log_heap_visible(), log_newpage_range(), log_split_page(), moveLeafs(), nextval_internal(), revmap_physical_extend(), SetSequence(), shiftList(), spgAddNodeAction(), spgSplitNodeAction(), vacuumLeafPage(), vacuumLeafRoot(), vacuumRedirectAndPlaceholder(), writeListPage(), and xlogVacuumPage().

◆ XLogRegisterData()

void XLogRegisterData	(	const void *	data,
		uint32	len
	)

Definition at line 368 of file xloginsert.c.

{
    XLogRecData *rdata;
 
    Assert(begininsert_called);
 
    if (num_rdatas >= max_rdatas)
        ereport(ERROR,
                (errmsg_internal("too much WAL data"),
                 errdetail_internal("%d out of %d data segments are already in use.",
                                    num_rdatas, max_rdatas)));
    rdata = &rdatas[num_rdatas++];
 
    rdata->data = data;
    rdata->len = len;
 
    /*
     * we use the mainrdata_last pointer to track the end of the chain, so no
     * need to clear 'next' here.
     */
 
    mainrdata_last->next = rdata;
    mainrdata_last = rdata;
 
    mainrdata_len += len;
}

References Assert, begininsert_called, XLogRecData::data, data, ereport, errdetail_internal(), errmsg_internal(), ERROR, fb(), len, mainrdata_last, mainrdata_len, max_rdatas, XLogRecData::next, num_rdatas, and rdatas.

Referenced by _bt_allocbuf(), _bt_dedup_pass(), _bt_delitems_delete(), _bt_delitems_vacuum(), _bt_getroot(), _bt_insertonpg(), _bt_mark_page_halfdead(), _bt_newlevel(), _bt_split(), _bt_unlink_halfdead_page(), _hash_addovflpage(), _hash_doinsert(), _hash_expandtable(), _hash_freeovflpage(), _hash_init(), _hash_splitbucket(), _hash_squeezebucket(), _hash_vacuum_one_page(), addLeafTuple(), AssignTransactionId(), brin_doinsert(), brin_doupdate(), brinbuild(), brinRevmapDesummarizeRange(), CreateCheckPoint(), CreateDatabaseUsingFileCopy(), CreateDirAndVersionFile(), CreateEndOfRecoveryRecord(), CreateOverwriteContrecordRecord(), createPostingTree(), CreateTableSpace(), do_pg_backup_stop(), doPickSplit(), DropTableSpace(), EndPrepare(), ExecuteTruncateGuts(), fill_seq_fork_with_data(), ginDeletePage(), ginHeapTupleFastInsert(), ginPlaceToPage(), ginUpdateStats(), gistXLogAssignLSN(), gistXLogDelete(), gistXLogPageDelete(), gistXLogPageReuse(), gistXLogSplit(), gistXLogUpdate(), hashbucketcleanup(), hashbulkdelete(), heap_abort_speculative(), heap_delete(), heap_finish_speculative(), heap_inplace_update_and_unlock(), heap_insert(), heap_lock_tuple(), heap_lock_updated_tuple_rec(), heap_multi_insert(), heap_update(), log_heap_new_cid(), log_heap_prune_and_freeze(), log_heap_update(), log_heap_visible(), log_smgrcreate(), LogAccessExclusiveLocks(), LogCurrentRunningXacts(), logical_heap_rewrite_flush_mappings(), LogLogicalInvalidations(), LogLogicalMessage(), LogStandbyInvalidations(), movedb(), moveLeafs(), MultiXactIdCreateFromMembers(), nextval_internal(), pg_truncate_visibility_map(), RelationTruncate(), remove_dbtablespaces(), replorigin_advance(), replorigin_state_clear(), revmap_physical_extend(), SetSequence(), shiftList(), spgAddNodeAction(), spgSplitNodeAction(), test_custom_rmgrs_insert_wal_record(), UpdateFullPageWrites(), vacuumLeafPage(), vacuumLeafRoot(), vacuumRedirectAndPlaceholder(), write_logical_decoding_status_update_record(), write_relmap_file(), writeListPage(), WriteMTruncateXlogRec(), WriteTruncateXlogRec(), WriteTruncateXlogRec(), XactLogAbortRecord(), XactLogCommitRecord(), XLogPutNextOid(), XLogReportParameters(), XLogRestorePoint(), and XLogSimpleInsertInt64().

◆ XLogResetInsertion()

void XLogResetInsertion ( void )

Definition at line 225 of file xloginsert.c.

{
    int         i;
 
    for (i = 0; i < max_registered_block_id; i++)
        registered_buffers[i].in_use = false;
 
    num_rdatas = 0;
    max_registered_block_id = 0;
    mainrdata_len = 0;
    mainrdata_last = (XLogRecData *) &mainrdata_head;
    curinsert_flags = 0;
    begininsert_called = false;
}

References begininsert_called, curinsert_flags, i, mainrdata_head, mainrdata_last, mainrdata_len, max_registered_block_id, num_rdatas, and registered_buffers.

Referenced by AbortSubTransaction(), AbortTransaction(), and XLogInsert().

◆ XLogSaveBufferForHint()

XLogRecPtr XLogSaveBufferForHint	(	Buffer	buffer,
		bool	buffer_std
	)

Definition at line 1087 of file xloginsert.c.

{
    XLogRecPtr  recptr = InvalidXLogRecPtr;
    XLogRecPtr  lsn;
    XLogRecPtr  RedoRecPtr;
 
    /*
     * Ensure no checkpoint can change our view of RedoRecPtr.
     */
    Assert((MyProc->delayChkptFlags & DELAY_CHKPT_START) != 0);
 
    /*
     * Update RedoRecPtr so that we can make the right decision
     */
    RedoRecPtr = GetRedoRecPtr();
 
    /*
     * We assume page LSN is first data on *every* page that can be passed to
     * XLogInsert, whether it has the standard page layout or not. Since we're
     * only holding a share-lock on the page, we must take the buffer header
     * lock when we look at the LSN.
     */
    lsn = BufferGetLSNAtomic(buffer);
 
    if (lsn <= RedoRecPtr)
    {
        int         flags = 0;
        PGAlignedBlock copied_buffer;
        char       *origdata = (char *) BufferGetBlock(buffer);
        RelFileLocator rlocator;
        ForkNumber  forkno;
        BlockNumber blkno;
 
        /*
         * Copy buffer so we don't have to worry about concurrent hint bit or
         * lsn updates. We assume pd_lower/upper cannot be changed without an
         * exclusive lock, so the contents bkp are not racy.
         */
        if (buffer_std)
        {
            /* Assume we can omit data between pd_lower and pd_upper */
            Page        page = BufferGetPage(buffer);
            uint16      lower = ((PageHeader) page)->pd_lower;
            uint16      upper = ((PageHeader) page)->pd_upper;
 
            memcpy(copied_buffer.data, origdata, lower);
            memcpy(copied_buffer.data + upper, origdata + upper, BLCKSZ - upper);
        }
        else
            memcpy(copied_buffer.data, origdata, BLCKSZ);
 
        XLogBeginInsert();
 
        if (buffer_std)
            flags |= REGBUF_STANDARD;
 
        BufferGetTag(buffer, &rlocator, &forkno, &blkno);
        XLogRegisterBlock(0, &rlocator, forkno, blkno, copied_buffer.data, flags);
 
        recptr = XLogInsert(RM_XLOG_ID, XLOG_FPI_FOR_HINT);
    }
 
    return recptr;
}

References Assert, BufferGetBlock(), BufferGetLSNAtomic(), BufferGetPage(), BufferGetTag(), DELAY_CHKPT_START, PGPROC::delayChkptFlags, fb(), GetRedoRecPtr(), InvalidXLogRecPtr, lower(), MyProc, RedoRecPtr, REGBUF_STANDARD, upper(), XLOG_FPI_FOR_HINT, XLogBeginInsert(), XLogInsert(), and XLogRegisterBlock().

Referenced by MarkBufferDirtyHint().

◆ XLogSetRecordFlags()

void XLogSetRecordFlags ( uint8 flags )

Definition at line 460 of file xloginsert.c.

{
    Assert(begininsert_called);
    curinsert_flags |= flags;
}

References Assert, begininsert_called, and curinsert_flags.

Referenced by EndPrepare(), ExecuteTruncateGuts(), gistXLogAssignLSN(), heap_delete(), heap_finish_speculative(), heap_insert(), heap_multi_insert(), log_heap_update(), LogAccessExclusiveLocks(), LogCurrentRunningXacts(), LogLogicalMessage(), RequestXLogSwitch(), test_custom_rmgrs_insert_wal_record(), XactLogAbortRecord(), and XactLogCommitRecord().

◆ XLogSimpleInsertInt64()

XLogRecPtr XLogSimpleInsertInt64	(	RmgrId	rmid,
		uint8	info,
		int64	value
	)

Definition at line 543 of file xloginsert.c.

{
    XLogBeginInsert();
    XLogRegisterData(&value, sizeof(value));
    return XLogInsert(rmid, info);
}

References value, XLogBeginInsert(), XLogInsert(), and XLogRegisterData().

Referenced by ExtendCLOG(), ExtendCommitTs(), ExtendMultiXactMember(), and ExtendMultiXactOffset().

Variable Documentation

◆ begininsert_called

bool begininsert_called = false

static

Definition at line 134 of file xloginsert.c.

Referenced by XLogBeginInsert(), XLogInsert(), XLogRegisterBlock(), XLogRegisterBufData(), XLogRegisterBuffer(), XLogRegisterData(), XLogResetInsertion(), and XLogSetRecordFlags().

◆ curinsert_flags

uint8 curinsert_flags = 0

static

Definition at line 105 of file xloginsert.c.

Referenced by XLogInsert(), XLogRecordAssemble(), XLogResetInsertion(), and XLogSetRecordFlags().

◆ hdr_rdt

XLogRecData hdr_rdt

static

Definition at line 115 of file xloginsert.c.

Referenced by XLogRecordAssemble().

◆ hdr_scratch

char* hdr_scratch = NULL

static

Definition at line 116 of file xloginsert.c.

Referenced by InitXLogInsert(), and XLogRecordAssemble().

◆ mainrdata_head

XLogRecData* mainrdata_head

static

Definition at line 100 of file xloginsert.c.

Referenced by XLogBeginInsert(), XLogRecordAssemble(), and XLogResetInsertion().

◆ mainrdata_last

XLogRecData* mainrdata_last = (XLogRecData *) &mainrdata_head

static

Definition at line 101 of file xloginsert.c.

Referenced by XLogBeginInsert(), XLogRecordAssemble(), XLogRegisterData(), and XLogResetInsertion().

◆ mainrdata_len

uint64 mainrdata_len

static

Definition at line 102 of file xloginsert.c.

Referenced by XLogBeginInsert(), XLogRecordAssemble(), XLogRegisterData(), and XLogResetInsertion().

◆ max_rdatas

int max_rdatas

static

Definition at line 132 of file xloginsert.c.

Referenced by InitXLogInsert(), XLogEnsureRecordSpace(), XLogRegisterBufData(), and XLogRegisterData().

◆ max_registered_block_id

int max_registered_block_id = 0

static

Definition at line 93 of file xloginsert.c.

Referenced by XLogBeginInsert(), XLogRecordAssemble(), XLogRegisterBlock(), XLogRegisterBuffer(), and XLogResetInsertion().

◆ max_registered_buffers

int max_registered_buffers

static

Definition at line 92 of file xloginsert.c.

Referenced by InitXLogInsert(), XLogEnsureRecordSpace(), XLogRegisterBlock(), and XLogRegisterBuffer().

◆ num_rdatas

int num_rdatas

static

Definition at line 131 of file xloginsert.c.

Referenced by XLogRegisterBufData(), XLogRegisterData(), and XLogResetInsertion().

◆ rdatas

XLogRecData* rdatas

static

Definition at line 130 of file xloginsert.c.

Referenced by InitXLogInsert(), XLogEnsureRecordSpace(), XLogRegisterBufData(), and XLogRegisterData().

◆ registered_buffers

registered_buffer* registered_buffers

static

Definition at line 91 of file xloginsert.c.

Referenced by InitXLogInsert(), XLogEnsureRecordSpace(), XLogRecordAssemble(), XLogRegisterBlock(), XLogRegisterBufData(), XLogRegisterBuffer(), and XLogResetInsertion().

◆ xloginsert_cxt

MemoryContext xloginsert_cxt

static

Definition at line 137 of file xloginsert.c.

Referenced by InitXLogInsert().

Variables
static registered_buffer *	registered_buffers

static int	max_registered_buffers

static int	max_registered_block_id = 0

static XLogRecData *	mainrdata_head

static XLogRecData *	mainrdata_last = (XLogRecData *) &mainrdata_head

static uint64	mainrdata_len

static uint8	curinsert_flags = 0

static XLogRecData	hdr_rdt

static char *	hdr_scratch = NULL

static XLogRecData *	rdatas

static int	num_rdatas

static int	max_rdatas

static bool	begininsert_called = false

static MemoryContext	xloginsert_cxt

Data Structures

Macros

Functions

Variables

Macro Definition Documentation

◆ COMPRESS_BUFSIZE

◆ HEADER_SCRATCH_SIZE

◆ LZ4_MAX_BLCKSZ

◆ PGLZ_MAX_BLCKSZ

◆ SizeOfXlogOrigin

◆ SizeOfXLogTransactionId

◆ ZSTD_MAX_BLCKSZ

Function Documentation

◆ InitXLogInsert()

◆ log_newpage()

◆ log_newpage_buffer()

◆ log_newpage_range()

◆ log_newpages()

◆ XLogBeginInsert()

◆ XLogCheckBufferNeedsBackup()

◆ XLogCompressBackupBlock()

◆ XLogEnsureRecordSpace()

◆ XLogInsert()

◆ XLogRecordAssemble()

◆ XLogRegisterBlock()

◆ XLogRegisterBufData()

◆ XLogRegisterBuffer()

◆ XLogRegisterData()

◆ XLogResetInsertion()

◆ XLogSaveBufferForHint()

◆ XLogSetRecordFlags()

◆ XLogSimpleInsertInt64()

Variable Documentation

◆ begininsert_called

◆ curinsert_flags

◆ hdr_rdt

◆ hdr_scratch

◆ mainrdata_head

◆ mainrdata_last

◆ mainrdata_len

◆ max_rdatas

◆ max_registered_block_id

◆ max_registered_buffers

◆ num_rdatas

◆ rdatas

◆ registered_buffers

◆ xloginsert_cxt