brin_pageops.c File Reference

#include "postgres.h"
#include "access/brin_page.h"
#include "access/brin_pageops.h"
#include "access/brin_revmap.h"
#include "access/brin_xlog.h"
#include "access/xloginsert.h"
#include "miscadmin.h"
#include "storage/bufmgr.h"
#include "storage/freespace.h"
#include "storage/lmgr.h"
#include "storage/smgr.h"
#include "utils/rel.h"

Include dependency graph for brin_pageops.c:

Go to the source code of this file.

Macros
#define	BrinMaxItemSize

Functions
static Buffer	brin_getinsertbuffer (Relation irel, Buffer oldbuf, Size itemsz, bool *extended)
static Size	br_page_get_freespace (Page page)
static void	brin_initialize_empty_new_buffer (Relation idxrel, Buffer buffer)
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, 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)

Macro Definition Documentation

BrinMaxItemSize

#define BrinMaxItemSize

Value:

    MAXALIGN_DOWN(BLCKSZ - \
                  (MAXALIGN(SizeOfPageHeaderData + \
                            sizeof(ItemIdData)) + \
                   MAXALIGN(sizeof(BrinSpecialSpace))))

Definition at line 29 of file brin_pageops.c.

Function Documentation

br_page_get_freespace()

static Size br_page_get_freespace ( Page  page )

static

Definition at line 913 of file brin_pageops.c.

{
    if (!BRIN_IS_REGULAR_PAGE(page) ||
        (BrinPageFlags(page) & BRIN_EVACUATE_PAGE) != 0)
        return 0;
    else
        return PageGetFreeSpace(page);
}

References BRIN_EVACUATE_PAGE, BRIN_IS_REGULAR_PAGE, BrinPageFlags, and PageGetFreeSpace().

Referenced by brin_doinsert(), brin_doupdate(), brin_getinsertbuffer(), brin_initialize_empty_new_buffer(), and brin_page_cleanup().

brin_can_do_samepage_update()

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

Definition at line 324 of file brin_pageops.c.

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

References BufferGetPage(), 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,
		BrinTuple *	tup,
		Size	itemsz
	)

Definition at line 343 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, (Item) 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((char *) &xlrec, SizeOfBrinInsert);
 
        XLogRegisterBuffer(0, *buffer, REGBUF_STANDARD | (extended ? REGBUF_WILL_INIT : 0));
        XLogRegisterBufData(0, (char *) 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, FreeSpaceMapVacuumRange(), xl_brin_insert::heapBlk, InvalidBuffer, InvalidOffsetNumber, ItemPointerSet(), LockBuffer(), MarkBufferDirty(), MAXALIGN, xl_brin_insert::offnum, PageAddItem, PageSetLSN(), xl_brin_insert::pagesPerRange, 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 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
	)

Definition at line 54 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, (Item) unconstify(BrinTuple *, 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((char *) &xlrec, SizeOfBrinSamepageUpdate);
 
            XLogRegisterBuffer(0, oldbuf, REGBUF_STANDARD);
            XLogRegisterBufData(0, (char *) unconstify(BrinTuple *, 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, (Item) unconstify(BrinTuple *, 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((char *) &xlrec, SizeOfBrinUpdate);
 
            XLogRegisterBuffer(0, newbuf, REGBUF_STANDARD | (extended ? REGBUF_WILL_INIT : 0));
            XLogRegisterBufData(0, (char *) unconstify(BrinTuple *, 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, FreeSpaceMapVacuumRange(), xl_brin_insert::heapBlk, xl_brin_update::insert, InvalidBlockNumber, InvalidBuffer, InvalidOffsetNumber, ItemIdGetLength, ItemIdIsNormal, ItemPointerSet(), LockBuffer(), MarkBufferDirty(), MAXALIGN, xl_brin_insert::offnum, xl_brin_samepage_update::offnum, xl_brin_update::oldOffnum, PageAddItem, PageGetItem(), PageGetItemId(), PageGetMaxOffsetNumber(), PageIndexTupleDeleteNoCompact(), PageIndexTupleOverwrite(), PageSetLSN(), xl_brin_insert::pagesPerRange, RecordPageWithFreeSpace(), REGBUF_STANDARD, REGBUF_WILL_INIT, RelationGetRelationName, RelationNeedsWAL, SizeOfBrinSamepageUpdate, SizeOfBrinUpdate, START_CRIT_SECTION, unconstify, 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
	)

Definition at line 565 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, BrinTuple::bt_blkno, buf, BUFFER_LOCK_SHARE, BUFFER_LOCK_UNLOCK, BufferGetPage(), CHECK_FOR_INTERRUPTS, FirstOffsetNumber, ItemIdGetLength, ItemIdIsUsed, LockBuffer(), PageGetItem(), PageGetItemId(), PageGetMaxOffsetNumber(), and UnlockReleaseBuffer().

Referenced by revmap_physical_extend().

brin_getinsertbuffer()

static Buffer brin_getinsertbuffer ( Relation  irel, Buffer  oldbuf, Size  itemsz, bool *  extended  )

static

Definition at line 691 of file brin_pageops.c.

{
    BlockNumber oldblk;
    BlockNumber newblk;
    Page        page;
    Size        freespace;
 
    /* callers must have checked */
    Assert(itemsz <= BrinMaxItemSize);
 
    if (BufferIsValid(oldbuf))
        oldblk = BufferGetBlockNumber(oldbuf);
    else
        oldblk = InvalidBlockNumber;
 
    /* Choose initial target page, re-using existing target if known */
    newblk = RelationGetTargetBlock(irel);
    if (newblk == InvalidBlockNumber)
        newblk = GetPageWithFreeSpace(irel, itemsz);
 
    /*
     * Loop until we find a page with sufficient free space.  By the time we
     * return to caller out of this loop, both buffers are valid and locked;
     * if we have to restart here, neither page is locked and newblk isn't
     * pinned (if it's even valid).
     */
    for (;;)
    {
        Buffer      buf;
        bool        extensionLockHeld = false;
 
        CHECK_FOR_INTERRUPTS();
 
        *extended = false;
 
        if (newblk == InvalidBlockNumber)
        {
            /*
             * There's not enough free space in any existing index page,
             * according to the FSM: extend the relation to obtain a shiny new
             * page.
             */
            if (!RELATION_IS_LOCAL(irel))
            {
                LockRelationForExtension(irel, ExclusiveLock);
                extensionLockHeld = true;
            }
            buf = ReadBuffer(irel, P_NEW);
            newblk = BufferGetBlockNumber(buf);
            *extended = true;
 
            BRIN_elog((DEBUG2, "brin_getinsertbuffer: extending to page %u",
                       BufferGetBlockNumber(buf)));
        }
        else if (newblk == oldblk)
        {
            /*
             * There's an odd corner-case here where the FSM is out-of-date,
             * and gave us the old page.
             */
            buf = oldbuf;
        }
        else
        {
            buf = ReadBuffer(irel, newblk);
        }
 
        /*
         * We lock the old buffer first, if it's earlier than the new one; but
         * then we need to check that it hasn't been turned into a revmap page
         * concurrently.  If we detect that that happened, give up and tell
         * caller to start over.
         */
        if (BufferIsValid(oldbuf) && oldblk < newblk)
        {
            LockBuffer(oldbuf, BUFFER_LOCK_EXCLUSIVE);
            if (!BRIN_IS_REGULAR_PAGE(BufferGetPage(oldbuf)))
            {
                LockBuffer(oldbuf, BUFFER_LOCK_UNLOCK);
 
                /*
                 * It is possible that the new page was obtained from
                 * extending the relation.  In that case, we must be sure to
                 * record it in the FSM before leaving, because otherwise the
                 * space would be lost forever.  However, we cannot let an
                 * uninitialized page get in the FSM, so we need to initialize
                 * it first.
                 */
                if (*extended)
                    brin_initialize_empty_new_buffer(irel, buf);
 
                if (extensionLockHeld)
                    UnlockRelationForExtension(irel, ExclusiveLock);
 
                ReleaseBuffer(buf);
 
                if (*extended)
                {
                    FreeSpaceMapVacuumRange(irel, newblk, newblk + 1);
                    /* shouldn't matter, but don't confuse caller */
                    *extended = false;
                }
 
                return InvalidBuffer;
            }
        }
 
        LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
 
        if (extensionLockHeld)
            UnlockRelationForExtension(irel, ExclusiveLock);
 
        page = BufferGetPage(buf);
 
        /*
         * We have a new buffer to insert into.  Check that the new page has
         * enough free space, and return it if it does; otherwise start over.
         * (br_page_get_freespace also checks that the FSM didn't hand us a
         * page that has since been repurposed for the revmap.)
         */
        freespace = *extended ?
            BrinMaxItemSize : br_page_get_freespace(page);
        if (freespace >= itemsz)
        {
            RelationSetTargetBlock(irel, newblk);
 
            /*
             * Lock the old buffer if not locked already.  Note that in this
             * case we know for sure it's a regular page: it's later than the
             * new page we just got, which is not a revmap page, and revmap
             * pages are always consecutive.
             */
            if (BufferIsValid(oldbuf) && oldblk > newblk)
            {
                LockBuffer(oldbuf, BUFFER_LOCK_EXCLUSIVE);
                Assert(BRIN_IS_REGULAR_PAGE(BufferGetPage(oldbuf)));
            }
 
            return buf;
        }
 
        /* This page is no good. */
 
        /*
         * If an entirely new page does not contain enough free space for the
         * new item, then surely that item is oversized.  Complain loudly; but
         * first make sure we initialize the page and record it as free, for
         * next time.
         */
        if (*extended)
        {
            brin_initialize_empty_new_buffer(irel, buf);
            /* since this should not happen, skip FreeSpaceMapVacuum */
 
            ereport(ERROR,
                    (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
                     errmsg("index row size %zu exceeds maximum %zu for index \"%s\"",
                            itemsz, freespace, RelationGetRelationName(irel))));
            return InvalidBuffer;   /* keep compiler quiet */
        }
 
        if (newblk != oldblk)
            UnlockReleaseBuffer(buf);
        if (BufferIsValid(oldbuf) && oldblk <= newblk)
            LockBuffer(oldbuf, BUFFER_LOCK_UNLOCK);
 
        /*
         * Update the FSM with the new, presumably smaller, freespace value
         * for this page, then search for a new target page.
         */
        newblk = RecordAndGetPageWithFreeSpace(irel, newblk, freespace, itemsz);
    }
}

References Assert(), br_page_get_freespace(), BRIN_elog, brin_initialize_empty_new_buffer(), BRIN_IS_REGULAR_PAGE, BrinMaxItemSize, buf, BUFFER_LOCK_EXCLUSIVE, BUFFER_LOCK_UNLOCK, BufferGetBlockNumber(), BufferGetPage(), BufferIsValid(), CHECK_FOR_INTERRUPTS, DEBUG2, ereport, errcode(), errmsg(), ERROR, ExclusiveLock, FreeSpaceMapVacuumRange(), GetPageWithFreeSpace(), InvalidBlockNumber, InvalidBuffer, LockBuffer(), LockRelationForExtension(), P_NEW, ReadBuffer(), RecordAndGetPageWithFreeSpace(), RELATION_IS_LOCAL, RelationGetRelationName, RelationGetTargetBlock, RelationSetTargetBlock, ReleaseBuffer(), UnlockRelationForExtension(), and UnlockReleaseBuffer().

Referenced by brin_doinsert(), and brin_doupdate().

brin_initialize_empty_new_buffer()

static void brin_initialize_empty_new_buffer ( Relation  idxrel, Buffer  buffer  )

static

Definition at line 881 of file brin_pageops.c.

{
    Page        page;
 
    BRIN_elog((DEBUG2,
               "brin_initialize_empty_new_buffer: initializing blank page %u",
               BufferGetBlockNumber(buffer)));
 
    START_CRIT_SECTION();
    page = BufferGetPage(buffer);
    brin_page_init(page, BRIN_PAGETYPE_REGULAR);
    MarkBufferDirty(buffer);
    log_newpage_buffer(buffer, true);
    END_CRIT_SECTION();
 
    /*
     * We update the FSM for this page, but this is not WAL-logged.  This is
     * acceptable because VACUUM will scan the index and update the FSM with
     * pages whose FSM records were forgotten in a crash.
     */
    RecordPageWithFreeSpace(idxrel, BufferGetBlockNumber(buffer),
                            br_page_get_freespace(page));
}

References br_page_get_freespace(), BRIN_elog, brin_page_init(), BRIN_PAGETYPE_REGULAR, BufferGetBlockNumber(), BufferGetPage(), DEBUG2, END_CRIT_SECTION, log_newpage_buffer(), MarkBufferDirty(), RecordPageWithFreeSpace(), and START_CRIT_SECTION.

Referenced by brin_doupdate(), brin_getinsertbuffer(), and brin_page_cleanup().

brin_metapage_init()

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

Definition at line 487 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
	)

Definition at line 625 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(), LockBuffer(), LockRelationForExtension(), PageIsNew(), RecordPageWithFreeSpace(), ShareLock, and UnlockRelationForExtension().

Referenced by brin_vacuum_scan().

brin_page_init()

void brin_page_init	(	Page	page,
		uint16	type
	)

Definition at line 476 of file brin_pageops.c.

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

References BrinPageType, PageInit(), and generate_unaccent_rules::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
	)

Definition at line 525 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(), FirstOffsetNumber, ItemIdIsUsed, MarkBufferDirtyHint(), PageGetItemId(), PageGetMaxOffsetNumber(), and PageIsNew().

Referenced by revmap_physical_extend().