brin_pageops.h File Reference

#include "access/brin_revmap.h"

Include dependency graph for brin_pageops.h:

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Go to the source code of this file.

Functions
bool	brin_doupdate (Relation idxrel, BlockNumber pagesPerRange, BrinRevmap *revmap, BlockNumber heapBlk, Buffer oldbuf, OffsetNumber oldoff, const BrinTuple *origtup, Size origsz, const BrinTuple *newtup, Size newsz, bool samepage)
bool	brin_can_do_samepage_update (Buffer buffer, Size origsz, Size newsz)
OffsetNumber	brin_doinsert (Relation idxrel, BlockNumber pagesPerRange, BrinRevmap *revmap, Buffer *buffer, BlockNumber heapBlk, const BrinTuple *tup, Size itemsz)
void	brin_page_init (Page page, uint16 type)
void	brin_metapage_init (Page page, BlockNumber pagesPerRange, uint16 version)
bool	brin_start_evacuating_page (Relation idxRel, Buffer buf)
void	brin_evacuate_page (Relation idxRel, BlockNumber pagesPerRange, BrinRevmap *revmap, Buffer buf)
void	brin_page_cleanup (Relation idxrel, Buffer buf)

Function Documentation

brin_can_do_samepage_update()

bool brin_can_do_samepage_update ( Buffer  buffer, Size  origsz, Size  newsz  )

extern

Definition at line 322 of file brin_pageops.c.

{
    return
        ((newsz <= origsz) ||
         PageGetExactFreeSpace(BufferGetPage(buffer)) >= (newsz - origsz));
}

References BufferGetPage(), fb(), and PageGetExactFreeSpace().

Referenced by brin_doupdate(), brininsert(), and summarize_range().

brin_doinsert()

OffsetNumber brin_doinsert ( Relation  idxrel, BlockNumber  pagesPerRange, BrinRevmap *  revmap, Buffer *  buffer, BlockNumber  heapBlk, const BrinTuple *  tup, Size  itemsz  )

extern

Definition at line 341 of file brin_pageops.c.

{
    Page        page;
    BlockNumber blk;
    OffsetNumber off;
    Size        freespace = 0;
    Buffer      revmapbuf;
    ItemPointerData tid;
    bool        extended;
 
    Assert(itemsz == MAXALIGN(itemsz));
 
    /* If the item is oversized, don't even bother. */
    if (itemsz > BrinMaxItemSize)
    {
        ereport(ERROR,
                (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
                 errmsg("index row size %zu exceeds maximum %zu for index \"%s\"",
                        itemsz, BrinMaxItemSize, RelationGetRelationName(idxrel))));
        return InvalidOffsetNumber; /* keep compiler quiet */
    }
 
    /* Make sure the revmap is long enough to contain the entry we need */
    brinRevmapExtend(revmap, heapBlk);
 
    /*
     * Acquire lock on buffer supplied by caller, if any.  If it doesn't have
     * enough space, unpin it to obtain a new one below.
     */
    if (BufferIsValid(*buffer))
    {
        /*
         * It's possible that another backend (or ourselves!) extended the
         * revmap over the page we held a pin on, so we cannot assume that
         * it's still a regular page.
         */
        LockBuffer(*buffer, BUFFER_LOCK_EXCLUSIVE);
        if (br_page_get_freespace(BufferGetPage(*buffer)) < itemsz)
        {
            UnlockReleaseBuffer(*buffer);
            *buffer = InvalidBuffer;
        }
    }
 
    /*
     * If we still don't have a usable buffer, have brin_getinsertbuffer
     * obtain one for us.
     */
    if (!BufferIsValid(*buffer))
    {
        do
            *buffer = brin_getinsertbuffer(idxrel, InvalidBuffer, itemsz, &extended);
        while (!BufferIsValid(*buffer));
    }
    else
        extended = false;
 
    /* Now obtain lock on revmap buffer */
    revmapbuf = brinLockRevmapPageForUpdate(revmap, heapBlk);
 
    page = BufferGetPage(*buffer);
    blk = BufferGetBlockNumber(*buffer);
 
    /* Execute the actual insertion */
    START_CRIT_SECTION();
    if (extended)
        brin_page_init(page, BRIN_PAGETYPE_REGULAR);
    off = PageAddItem(page, tup, itemsz, InvalidOffsetNumber, false, false);
    if (off == InvalidOffsetNumber)
        elog(ERROR, "failed to add BRIN tuple to new page");
    MarkBufferDirty(*buffer);
 
    /* needed to update FSM below */
    if (extended)
        freespace = br_page_get_freespace(page);
 
    ItemPointerSet(&tid, blk, off);
    brinSetHeapBlockItemptr(revmapbuf, pagesPerRange, heapBlk, tid);
    MarkBufferDirty(revmapbuf);
 
    /* XLOG stuff */
    if (RelationNeedsWAL(idxrel))
    {
        xl_brin_insert xlrec;
        XLogRecPtr  recptr;
        uint8       info;
 
        info = XLOG_BRIN_INSERT | (extended ? XLOG_BRIN_INIT_PAGE : 0);
        xlrec.heapBlk = heapBlk;
        xlrec.pagesPerRange = pagesPerRange;
        xlrec.offnum = off;
 
        XLogBeginInsert();
        XLogRegisterData(&xlrec, SizeOfBrinInsert);
 
        XLogRegisterBuffer(0, *buffer, REGBUF_STANDARD | (extended ? REGBUF_WILL_INIT : 0));
        XLogRegisterBufData(0, tup, itemsz);
 
        XLogRegisterBuffer(1, revmapbuf, 0);
 
        recptr = XLogInsert(RM_BRIN_ID, info);
 
        PageSetLSN(page, recptr);
        PageSetLSN(BufferGetPage(revmapbuf), recptr);
    }
 
    END_CRIT_SECTION();
 
    /* Tuple is firmly on buffer; we can release our locks */
    LockBuffer(*buffer, BUFFER_LOCK_UNLOCK);
    LockBuffer(revmapbuf, BUFFER_LOCK_UNLOCK);
 
    BRIN_elog((DEBUG2, "inserted tuple (%u,%u) for range starting at %u",
               blk, off, heapBlk));
 
    if (extended)
    {
        RecordPageWithFreeSpace(idxrel, blk, freespace);
        FreeSpaceMapVacuumRange(idxrel, blk, blk + 1);
    }
 
    return off;
}

References Assert, br_page_get_freespace(), BRIN_elog, brin_getinsertbuffer(), brin_page_init(), BRIN_PAGETYPE_REGULAR, brinLockRevmapPageForUpdate(), BrinMaxItemSize, brinRevmapExtend(), brinSetHeapBlockItemptr(), BUFFER_LOCK_EXCLUSIVE, BUFFER_LOCK_UNLOCK, BufferGetBlockNumber(), BufferGetPage(), BufferIsValid(), DEBUG2, elog, END_CRIT_SECTION, ereport, errcode(), errmsg(), ERROR, fb(), FreeSpaceMapVacuumRange(), xl_brin_insert::heapBlk, InvalidBuffer, InvalidOffsetNumber, ItemPointerSet(), LockBuffer(), MarkBufferDirty(), MAXALIGN, PageAddItem, PageSetLSN(), RecordPageWithFreeSpace(), REGBUF_STANDARD, REGBUF_WILL_INIT, RelationGetRelationName, RelationNeedsWAL, SizeOfBrinInsert, START_CRIT_SECTION, UnlockReleaseBuffer(), XLOG_BRIN_INIT_PAGE, XLOG_BRIN_INSERT, XLogBeginInsert(), XLogInsert(), XLogRegisterBufData(), XLogRegisterBuffer(), and XLogRegisterData().

Referenced by _brin_parallel_merge(), brin_fill_empty_ranges(), form_and_insert_tuple(), and summarize_range().

brin_doupdate()

bool brin_doupdate ( Relation  idxrel, BlockNumber  pagesPerRange, BrinRevmap *  revmap, BlockNumber  heapBlk, Buffer  oldbuf, OffsetNumber  oldoff, const BrinTuple *  origtup, Size  origsz, const BrinTuple *  newtup, Size  newsz, bool  samepage  )

extern

Definition at line 53 of file brin_pageops.c.

{
    Page        oldpage;
    ItemId      oldlp;
    BrinTuple  *oldtup;
    Size        oldsz;
    Buffer      newbuf;
    BlockNumber newblk = InvalidBlockNumber;
    bool        extended;
 
    Assert(newsz == MAXALIGN(newsz));
 
    /* If the item is oversized, don't bother. */
    if (newsz > BrinMaxItemSize)
    {
        ereport(ERROR,
                (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
                 errmsg("index row size %zu exceeds maximum %zu for index \"%s\"",
                        newsz, BrinMaxItemSize, RelationGetRelationName(idxrel))));
        return false;           /* keep compiler quiet */
    }
 
    /* make sure the revmap is long enough to contain the entry we need */
    brinRevmapExtend(revmap, heapBlk);
 
    if (!samepage)
    {
        /* need a page on which to put the item */
        newbuf = brin_getinsertbuffer(idxrel, oldbuf, newsz, &extended);
        if (!BufferIsValid(newbuf))
        {
            Assert(!extended);
            return false;
        }
 
        /*
         * Note: it's possible (though unlikely) that the returned newbuf is
         * the same as oldbuf, if brin_getinsertbuffer determined that the old
         * buffer does in fact have enough space.
         */
        if (newbuf == oldbuf)
        {
            Assert(!extended);
            newbuf = InvalidBuffer;
        }
        else
            newblk = BufferGetBlockNumber(newbuf);
    }
    else
    {
        LockBuffer(oldbuf, BUFFER_LOCK_EXCLUSIVE);
        newbuf = InvalidBuffer;
        extended = false;
    }
    oldpage = BufferGetPage(oldbuf);
    oldlp = PageGetItemId(oldpage, oldoff);
 
    /*
     * Check that the old tuple wasn't updated concurrently: it might have
     * moved someplace else entirely, and for that matter the whole page
     * might've become a revmap page.  Note that in the first two cases
     * checked here, the "oldlp" we just calculated is garbage; but
     * PageGetItemId() is simple enough that it was safe to do that
     * calculation anyway.
     */
    if (!BRIN_IS_REGULAR_PAGE(oldpage) ||
        oldoff > PageGetMaxOffsetNumber(oldpage) ||
        !ItemIdIsNormal(oldlp))
    {
        LockBuffer(oldbuf, BUFFER_LOCK_UNLOCK);
 
        /*
         * If this happens, and the new buffer was obtained by extending the
         * relation, then we need to ensure we don't leave it uninitialized or
         * forget about it.
         */
        if (BufferIsValid(newbuf))
        {
            if (extended)
                brin_initialize_empty_new_buffer(idxrel, newbuf);
            UnlockReleaseBuffer(newbuf);
            if (extended)
                FreeSpaceMapVacuumRange(idxrel, newblk, newblk + 1);
        }
        return false;
    }
 
    oldsz = ItemIdGetLength(oldlp);
    oldtup = (BrinTuple *) PageGetItem(oldpage, oldlp);
 
    /*
     * ... or it might have been updated in place to different contents.
     */
    if (!brin_tuples_equal(oldtup, oldsz, origtup, origsz))
    {
        LockBuffer(oldbuf, BUFFER_LOCK_UNLOCK);
        if (BufferIsValid(newbuf))
        {
            /* As above, initialize and record new page if we got one */
            if (extended)
                brin_initialize_empty_new_buffer(idxrel, newbuf);
            UnlockReleaseBuffer(newbuf);
            if (extended)
                FreeSpaceMapVacuumRange(idxrel, newblk, newblk + 1);
        }
        return false;
    }
 
    /*
     * Great, the old tuple is intact.  We can proceed with the update.
     *
     * If there's enough room in the old page for the new tuple, replace it.
     *
     * Note that there might now be enough space on the page even though the
     * caller told us there isn't, if a concurrent update moved another tuple
     * elsewhere or replaced a tuple with a smaller one.
     */
    if (((BrinPageFlags(oldpage) & BRIN_EVACUATE_PAGE) == 0) &&
        brin_can_do_samepage_update(oldbuf, origsz, newsz))
    {
        START_CRIT_SECTION();
        if (!PageIndexTupleOverwrite(oldpage, oldoff, newtup, newsz))
            elog(ERROR, "failed to replace BRIN tuple");
        MarkBufferDirty(oldbuf);
 
        /* XLOG stuff */
        if (RelationNeedsWAL(idxrel))
        {
            xl_brin_samepage_update xlrec;
            XLogRecPtr  recptr;
            uint8       info = XLOG_BRIN_SAMEPAGE_UPDATE;
 
            xlrec.offnum = oldoff;
 
            XLogBeginInsert();
            XLogRegisterData(&xlrec, SizeOfBrinSamepageUpdate);
 
            XLogRegisterBuffer(0, oldbuf, REGBUF_STANDARD);
            XLogRegisterBufData(0, newtup, newsz);
 
            recptr = XLogInsert(RM_BRIN_ID, info);
 
            PageSetLSN(oldpage, recptr);
        }
 
        END_CRIT_SECTION();
 
        LockBuffer(oldbuf, BUFFER_LOCK_UNLOCK);
 
        if (BufferIsValid(newbuf))
        {
            /* As above, initialize and record new page if we got one */
            if (extended)
                brin_initialize_empty_new_buffer(idxrel, newbuf);
            UnlockReleaseBuffer(newbuf);
            if (extended)
                FreeSpaceMapVacuumRange(idxrel, newblk, newblk + 1);
        }
 
        return true;
    }
    else if (newbuf == InvalidBuffer)
    {
        /*
         * Not enough space, but caller said that there was. Tell them to
         * start over.
         */
        LockBuffer(oldbuf, BUFFER_LOCK_UNLOCK);
        return false;
    }
    else
    {
        /*
         * Not enough free space on the oldpage. Put the new tuple on the new
         * page, and update the revmap.
         */
        Page        newpage = BufferGetPage(newbuf);
        Buffer      revmapbuf;
        ItemPointerData newtid;
        OffsetNumber newoff;
        Size        freespace = 0;
 
        revmapbuf = brinLockRevmapPageForUpdate(revmap, heapBlk);
 
        START_CRIT_SECTION();
 
        /*
         * We need to initialize the page if it's newly obtained.  Note we
         * will WAL-log the initialization as part of the update, so we don't
         * need to do that here.
         */
        if (extended)
            brin_page_init(newpage, BRIN_PAGETYPE_REGULAR);
 
        PageIndexTupleDeleteNoCompact(oldpage, oldoff);
        newoff = PageAddItem(newpage, newtup, newsz, InvalidOffsetNumber, false, false);
        if (newoff == InvalidOffsetNumber)
            elog(ERROR, "failed to add BRIN tuple to new page");
        MarkBufferDirty(oldbuf);
        MarkBufferDirty(newbuf);
 
        /* needed to update FSM below */
        if (extended)
            freespace = br_page_get_freespace(newpage);
 
        ItemPointerSet(&newtid, newblk, newoff);
        brinSetHeapBlockItemptr(revmapbuf, pagesPerRange, heapBlk, newtid);
        MarkBufferDirty(revmapbuf);
 
        /* XLOG stuff */
        if (RelationNeedsWAL(idxrel))
        {
            xl_brin_update xlrec;
            XLogRecPtr  recptr;
            uint8       info;
 
            info = XLOG_BRIN_UPDATE | (extended ? XLOG_BRIN_INIT_PAGE : 0);
 
            xlrec.insert.offnum = newoff;
            xlrec.insert.heapBlk = heapBlk;
            xlrec.insert.pagesPerRange = pagesPerRange;
            xlrec.oldOffnum = oldoff;
 
            XLogBeginInsert();
 
            /* new page */
            XLogRegisterData(&xlrec, SizeOfBrinUpdate);
 
            XLogRegisterBuffer(0, newbuf, REGBUF_STANDARD | (extended ? REGBUF_WILL_INIT : 0));
            XLogRegisterBufData(0, newtup, newsz);
 
            /* revmap page */
            XLogRegisterBuffer(1, revmapbuf, 0);
 
            /* old page */
            XLogRegisterBuffer(2, oldbuf, REGBUF_STANDARD);
 
            recptr = XLogInsert(RM_BRIN_ID, info);
 
            PageSetLSN(oldpage, recptr);
            PageSetLSN(newpage, recptr);
            PageSetLSN(BufferGetPage(revmapbuf), recptr);
        }
 
        END_CRIT_SECTION();
 
        LockBuffer(revmapbuf, BUFFER_LOCK_UNLOCK);
        LockBuffer(oldbuf, BUFFER_LOCK_UNLOCK);
        UnlockReleaseBuffer(newbuf);
 
        if (extended)
        {
            RecordPageWithFreeSpace(idxrel, newblk, freespace);
            FreeSpaceMapVacuumRange(idxrel, newblk, newblk + 1);
        }
 
        return true;
    }
}

References Assert, br_page_get_freespace(), brin_can_do_samepage_update(), BRIN_EVACUATE_PAGE, brin_getinsertbuffer(), brin_initialize_empty_new_buffer(), BRIN_IS_REGULAR_PAGE, brin_page_init(), BRIN_PAGETYPE_REGULAR, brin_tuples_equal(), brinLockRevmapPageForUpdate(), BrinMaxItemSize, BrinPageFlags, brinRevmapExtend(), brinSetHeapBlockItemptr(), BUFFER_LOCK_EXCLUSIVE, BUFFER_LOCK_UNLOCK, BufferGetBlockNumber(), BufferGetPage(), BufferIsValid(), elog, END_CRIT_SECTION, ereport, errcode(), errmsg(), ERROR, fb(), FreeSpaceMapVacuumRange(), xl_brin_update::insert, InvalidBlockNumber, InvalidBuffer, InvalidOffsetNumber, ItemIdGetLength, ItemIdIsNormal, ItemPointerSet(), LockBuffer(), MarkBufferDirty(), MAXALIGN, xl_brin_insert::offnum, xl_brin_samepage_update::offnum, PageAddItem, PageGetItem(), PageGetItemId(), PageGetMaxOffsetNumber(), PageIndexTupleDeleteNoCompact(), PageIndexTupleOverwrite(), PageSetLSN(), RecordPageWithFreeSpace(), REGBUF_STANDARD, REGBUF_WILL_INIT, RelationGetRelationName, RelationNeedsWAL, SizeOfBrinSamepageUpdate, SizeOfBrinUpdate, START_CRIT_SECTION, UnlockReleaseBuffer(), XLOG_BRIN_INIT_PAGE, XLOG_BRIN_SAMEPAGE_UPDATE, XLOG_BRIN_UPDATE, XLogBeginInsert(), XLogInsert(), XLogRegisterBufData(), XLogRegisterBuffer(), and XLogRegisterData().

Referenced by brin_evacuate_page(), brininsert(), and summarize_range().

brin_evacuate_page()

void brin_evacuate_page ( Relation  idxRel, BlockNumber  pagesPerRange, BrinRevmap *  revmap, Buffer  buf  )

extern

Definition at line 562 of file brin_pageops.c.

{
    OffsetNumber off;
    OffsetNumber maxoff;
    Page        page;
    BrinTuple  *btup = NULL;
    Size        btupsz = 0;
 
    page = BufferGetPage(buf);
 
    Assert(BrinPageFlags(page) & BRIN_EVACUATE_PAGE);
 
    maxoff = PageGetMaxOffsetNumber(page);
    for (off = FirstOffsetNumber; off <= maxoff; off++)
    {
        BrinTuple  *tup;
        Size        sz;
        ItemId      lp;
 
        CHECK_FOR_INTERRUPTS();
 
        lp = PageGetItemId(page, off);
        if (ItemIdIsUsed(lp))
        {
            sz = ItemIdGetLength(lp);
            tup = (BrinTuple *) PageGetItem(page, lp);
            tup = brin_copy_tuple(tup, sz, btup, &btupsz);
 
            LockBuffer(buf, BUFFER_LOCK_UNLOCK);
 
            if (!brin_doupdate(idxRel, pagesPerRange, revmap, tup->bt_blkno,
                               buf, off, tup, sz, tup, sz, false))
                off--;          /* retry */
 
            LockBuffer(buf, BUFFER_LOCK_SHARE);
 
            /* It's possible that someone extended the revmap over this page */
            if (!BRIN_IS_REGULAR_PAGE(page))
                break;
        }
    }
 
    UnlockReleaseBuffer(buf);
}

References Assert, brin_copy_tuple(), brin_doupdate(), BRIN_EVACUATE_PAGE, BRIN_IS_REGULAR_PAGE, BrinPageFlags, buf, BUFFER_LOCK_SHARE, BUFFER_LOCK_UNLOCK, BufferGetPage(), CHECK_FOR_INTERRUPTS, fb(), FirstOffsetNumber, ItemIdGetLength, ItemIdIsUsed, LockBuffer(), PageGetItem(), PageGetItemId(), PageGetMaxOffsetNumber(), and UnlockReleaseBuffer().

Referenced by revmap_physical_extend().

brin_metapage_init()

void brin_metapage_init ( Page  page, BlockNumber  pagesPerRange, uint16  version  )

extern

Definition at line 484 of file brin_pageops.c.

{
    BrinMetaPageData *metadata;
 
    brin_page_init(page, BRIN_PAGETYPE_META);
 
    metadata = (BrinMetaPageData *) PageGetContents(page);
 
    metadata->brinMagic = BRIN_META_MAGIC;
    metadata->brinVersion = version;
    metadata->pagesPerRange = pagesPerRange;
 
    /*
     * Note we cheat here a little.  0 is not a valid revmap block number
     * (because it's the metapage buffer), but doing this enables the first
     * revmap page to be created when the index is.
     */
    metadata->lastRevmapPage = 0;
 
    /*
     * Set pd_lower just past the end of the metadata.  This is essential,
     * because without doing so, metadata will be lost if xlog.c compresses
     * the page.
     */
    ((PageHeader) page)->pd_lower =
        ((char *) metadata + sizeof(BrinMetaPageData)) - (char *) page;
}

References BRIN_META_MAGIC, brin_page_init(), BRIN_PAGETYPE_META, BrinMetaPageData::brinMagic, BrinMetaPageData::brinVersion, BrinMetaPageData::lastRevmapPage, PageGetContents(), and BrinMetaPageData::pagesPerRange.

Referenced by brin_xlog_createidx(), brinbuild(), and brinbuildempty().

brin_page_cleanup()

void brin_page_cleanup ( Relation  idxrel, Buffer  buf  )

extern

Definition at line 622 of file brin_pageops.c.

{
    Page        page = BufferGetPage(buf);
 
    /*
     * If a page was left uninitialized, initialize it now; also record it in
     * FSM.
     *
     * Somebody else might be extending the relation concurrently.  To avoid
     * re-initializing the page before they can grab the buffer lock, we
     * acquire the extension lock momentarily.  Since they hold the extension
     * lock from before getting the page and after its been initialized, we're
     * sure to see their initialization.
     */
    if (PageIsNew(page))
    {
        LockRelationForExtension(idxrel, ShareLock);
        UnlockRelationForExtension(idxrel, ShareLock);
 
        LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
        if (PageIsNew(page))
        {
            brin_initialize_empty_new_buffer(idxrel, buf);
            LockBuffer(buf, BUFFER_LOCK_UNLOCK);
            return;
        }
        LockBuffer(buf, BUFFER_LOCK_UNLOCK);
    }
 
    /* Nothing to be done for non-regular index pages */
    if (BRIN_IS_META_PAGE(BufferGetPage(buf)) ||
        BRIN_IS_REVMAP_PAGE(BufferGetPage(buf)))
        return;
 
    /* Measure free space and record it */
    RecordPageWithFreeSpace(idxrel, BufferGetBlockNumber(buf),
                            br_page_get_freespace(page));
}

References br_page_get_freespace(), brin_initialize_empty_new_buffer(), BRIN_IS_META_PAGE, BRIN_IS_REVMAP_PAGE, buf, BUFFER_LOCK_EXCLUSIVE, BUFFER_LOCK_UNLOCK, BufferGetBlockNumber(), BufferGetPage(), fb(), LockBuffer(), LockRelationForExtension(), PageIsNew(), RecordPageWithFreeSpace(), ShareLock, and UnlockRelationForExtension().

Referenced by brin_vacuum_scan().

brin_page_init()

void brin_page_init ( Page  page, uint16  type  )

extern

Definition at line 473 of file brin_pageops.c.

{
    PageInit(page, BLCKSZ, sizeof(BrinSpecialSpace));
 
    BrinPageType(page) = type;
}

References BrinPageType, fb(), PageInit(), and type.

Referenced by brin_doinsert(), brin_doupdate(), brin_initialize_empty_new_buffer(), brin_metapage_init(), brin_xlog_insert_update(), brin_xlog_revmap_extend(), and revmap_physical_extend().

brin_start_evacuating_page()

bool brin_start_evacuating_page ( Relation  idxRel, Buffer  buf  )

extern

Definition at line 522 of file brin_pageops.c.

{
    OffsetNumber off;
    OffsetNumber maxoff;
    Page        page;
 
    page = BufferGetPage(buf);
 
    if (PageIsNew(page))
        return false;
 
    maxoff = PageGetMaxOffsetNumber(page);
    for (off = FirstOffsetNumber; off <= maxoff; off++)
    {
        ItemId      lp;
 
        lp = PageGetItemId(page, off);
        if (ItemIdIsUsed(lp))
        {
            /*
             * Prevent other backends from adding more stuff to this page:
             * BRIN_EVACUATE_PAGE informs br_page_get_freespace that this page
             * can no longer be used to add new tuples.  Note that this flag
             * is not WAL-logged, except accidentally.
             */
            BrinPageFlags(page) |= BRIN_EVACUATE_PAGE;
            MarkBufferDirtyHint(buf, true);
 
            return true;
        }
    }
    return false;
}

References BRIN_EVACUATE_PAGE, BrinPageFlags, buf, BufferGetPage(), fb(), FirstOffsetNumber, ItemIdIsUsed, MarkBufferDirtyHint(), PageGetItemId(), PageGetMaxOffsetNumber(), and PageIsNew().

Referenced by revmap_physical_extend().