ginbtree.c File Reference

#include "postgres.h"
#include "access/gin_private.h"
#include "access/ginxlog.h"
#include "access/xloginsert.h"
#include "miscadmin.h"
#include "storage/predicate.h"
#include "utils/injection_point.h"
#include "utils/memutils.h"
#include "utils/rel.h"

Include dependency graph for ginbtree.c:

Go to the source code of this file.

Functions
static void	ginFindParents (GinBtree btree, GinBtreeStack *stack)
static bool	ginPlaceToPage (GinBtree btree, GinBtreeStack *stack, void *insertdata, BlockNumber updateblkno, Buffer childbuf, GinStatsData *buildStats)
static void	ginFinishSplit (GinBtree btree, GinBtreeStack *stack, bool freestack, GinStatsData *buildStats)
static void	ginFinishOldSplit (GinBtree btree, GinBtreeStack *stack, GinStatsData *buildStats, int access)
int	ginTraverseLock (Buffer buffer, bool searchMode)
GinBtreeStack *	ginFindLeafPage (GinBtree btree, bool searchMode, bool rootConflictCheck)
Buffer	ginStepRight (Buffer buffer, Relation index, int lockmode)
void	freeGinBtreeStack (GinBtreeStack *stack)
void	ginInsertValue (GinBtree btree, GinBtreeStack *stack, void *insertdata, GinStatsData *buildStats)

Function Documentation

freeGinBtreeStack()

void freeGinBtreeStack

(

GinBtreeStack *

stack

)

Definition at line 198 of file ginbtree.c.

{
    while (stack)
    {
        GinBtreeStack *tmp = stack->parent;
 
        if (stack->buffer != InvalidBuffer)
            ReleaseBuffer(stack->buffer);
 
        pfree(stack);
        stack = tmp;
    }
}

References GinBtreeStack::buffer, InvalidBuffer, GinBtreeStack::parent, pfree(), and ReleaseBuffer().

Referenced by entryLoadMoreItems(), ginEntryInsert(), ginFinishSplit(), ginInsertValue(), scanPostingTree(), and startScanEntry().

ginFindLeafPage()

GinBtreeStack* ginFindLeafPage	(	GinBtree	btree,
		bool	searchMode,
		bool	rootConflictCheck
	)

Definition at line 83 of file ginbtree.c.

{
    GinBtreeStack *stack;
 
    stack = (GinBtreeStack *) palloc(sizeof(GinBtreeStack));
    stack->blkno = btree->rootBlkno;
    stack->buffer = ReadBuffer(btree->index, btree->rootBlkno);
    stack->parent = NULL;
    stack->predictNumber = 1;
 
    if (rootConflictCheck)
        CheckForSerializableConflictIn(btree->index, NULL, btree->rootBlkno);
 
    for (;;)
    {
        Page        page;
        BlockNumber child;
        int         access;
 
        stack->off = InvalidOffsetNumber;
 
        page = BufferGetPage(stack->buffer);
 
        access = ginTraverseLock(stack->buffer, searchMode);
 
        /*
         * If we're going to modify the tree, finish any incomplete splits we
         * encounter on the way.
         */
        if (!searchMode && GinPageIsIncompleteSplit(page))
            ginFinishOldSplit(btree, stack, NULL, access);
 
        /*
         * ok, page is correctly locked, we should check to move right ..,
         * root never has a right link, so small optimization
         */
        while (btree->fullScan == false && stack->blkno != btree->rootBlkno &&
               btree->isMoveRight(btree, page))
        {
            BlockNumber rightlink = GinPageGetOpaque(page)->rightlink;
 
            if (rightlink == InvalidBlockNumber)
                /* rightmost page */
                break;
 
            stack->buffer = ginStepRight(stack->buffer, btree->index, access);
            stack->blkno = rightlink;
            page = BufferGetPage(stack->buffer);
 
            if (!searchMode && GinPageIsIncompleteSplit(page))
                ginFinishOldSplit(btree, stack, NULL, access);
        }
 
        if (GinPageIsLeaf(page))    /* we found, return locked page */
            return stack;
 
        /* now we have correct buffer, try to find child */
        child = btree->findChildPage(btree, stack);
 
        LockBuffer(stack->buffer, GIN_UNLOCK);
        Assert(child != InvalidBlockNumber);
        Assert(stack->blkno != child);
 
        if (searchMode)
        {
            /* in search mode we may forget path to leaf */
            stack->blkno = child;
            stack->buffer = ReleaseAndReadBuffer(stack->buffer, btree->index, stack->blkno);
        }
        else
        {
            GinBtreeStack *ptr = (GinBtreeStack *) palloc(sizeof(GinBtreeStack));
 
            ptr->parent = stack;
            stack = ptr;
            stack->blkno = child;
            stack->buffer = ReadBuffer(btree->index, stack->blkno);
            stack->predictNumber = 1;
        }
    }
}

References Assert, GinBtreeStack::blkno, GinBtreeStack::buffer, BufferGetPage(), CheckForSerializableConflictIn(), GinBtreeData::findChildPage, GinBtreeData::fullScan, GIN_UNLOCK, ginFinishOldSplit(), GinPageGetOpaque, GinPageIsIncompleteSplit, GinPageIsLeaf, ginStepRight(), ginTraverseLock(), GinBtreeData::index, InvalidBlockNumber, InvalidOffsetNumber, GinBtreeData::isMoveRight, LockBuffer(), GinBtreeStack::off, palloc(), GinBtreeStack::parent, GinBtreeStack::predictNumber, ReadBuffer(), ReleaseAndReadBuffer(), and GinBtreeData::rootBlkno.

Referenced by entryLoadMoreItems(), ginEntryInsert(), ginInsertItemPointers(), ginScanBeginPostingTree(), and startScanEntry().

ginFindParents()

static void ginFindParents ( GinBtree  btree, GinBtreeStack *  stack  )

static

Definition at line 218 of file ginbtree.c.

{
    Page        page;
    Buffer      buffer;
    BlockNumber blkno,
                leftmostBlkno;
    OffsetNumber offset;
    GinBtreeStack *root;
    GinBtreeStack *ptr;
 
    /*
     * Unwind the stack all the way up to the root, leaving only the root
     * item.
     *
     * Be careful not to release the pin on the root page! The pin on root
     * page is required to lock out concurrent vacuums on the tree.
     */
    root = stack->parent;
    while (root->parent)
    {
        ReleaseBuffer(root->buffer);
        root = root->parent;
    }
 
    Assert(root->blkno == btree->rootBlkno);
    Assert(BufferGetBlockNumber(root->buffer) == btree->rootBlkno);
    root->off = InvalidOffsetNumber;
 
    blkno = root->blkno;
    buffer = root->buffer;
 
    ptr = (GinBtreeStack *) palloc(sizeof(GinBtreeStack));
 
    for (;;)
    {
        LockBuffer(buffer, GIN_EXCLUSIVE);
        page = BufferGetPage(buffer);
        if (GinPageIsLeaf(page))
            elog(ERROR, "Lost path");
 
        if (GinPageIsIncompleteSplit(page))
        {
            Assert(blkno != btree->rootBlkno);
            ptr->blkno = blkno;
            ptr->buffer = buffer;
 
            /*
             * parent may be wrong, but if so, the ginFinishSplit call will
             * recurse to call ginFindParents again to fix it.
             */
            ptr->parent = root;
            ptr->off = InvalidOffsetNumber;
 
            ginFinishOldSplit(btree, ptr, NULL, GIN_EXCLUSIVE);
        }
 
        leftmostBlkno = btree->getLeftMostChild(btree, page);
 
        while ((offset = btree->findChildPtr(btree, page, stack->blkno, InvalidOffsetNumber)) == InvalidOffsetNumber)
        {
            blkno = GinPageGetOpaque(page)->rightlink;
            if (blkno == InvalidBlockNumber)
            {
                /* Link not present in this level */
                LockBuffer(buffer, GIN_UNLOCK);
                /* Do not release pin on the root buffer */
                if (buffer != root->buffer)
                    ReleaseBuffer(buffer);
                break;
            }
            buffer = ginStepRight(buffer, btree->index, GIN_EXCLUSIVE);
            page = BufferGetPage(buffer);
 
            /* finish any incomplete splits, as above */
            if (GinPageIsIncompleteSplit(page))
            {
                Assert(blkno != btree->rootBlkno);
                ptr->blkno = blkno;
                ptr->buffer = buffer;
                ptr->parent = root;
                ptr->off = InvalidOffsetNumber;
 
                ginFinishOldSplit(btree, ptr, NULL, GIN_EXCLUSIVE);
            }
        }
 
        if (blkno != InvalidBlockNumber)
        {
            ptr->blkno = blkno;
            ptr->buffer = buffer;
            ptr->parent = root; /* it may be wrong, but in next call we will
                                 * correct */
            ptr->off = offset;
            stack->parent = ptr;
            return;
        }
 
        /* Descend down to next level */
        blkno = leftmostBlkno;
        buffer = ReadBuffer(btree->index, blkno);
    }
}

References Assert, GinBtreeStack::blkno, GinBtreeStack::buffer, BufferGetBlockNumber(), BufferGetPage(), elog, ERROR, GinBtreeData::findChildPtr, GinBtreeData::getLeftMostChild, GIN_EXCLUSIVE, GIN_UNLOCK, ginFinishOldSplit(), GinPageGetOpaque, GinPageIsIncompleteSplit, GinPageIsLeaf, ginStepRight(), GinBtreeData::index, InvalidBlockNumber, InvalidOffsetNumber, LockBuffer(), GinBtreeStack::off, palloc(), GinBtreeStack::parent, ReadBuffer(), ReleaseBuffer(), root, and GinBtreeData::rootBlkno.

Referenced by ginFinishSplit().

ginFinishOldSplit()

static void ginFinishOldSplit ( GinBtree  btree, GinBtreeStack *  stack, GinStatsData *  buildStats, int  access  )

static

Definition at line 779 of file ginbtree.c.

{
    INJECTION_POINT("gin-finish-incomplete-split");
    elog(DEBUG1, "finishing incomplete split of block %u in gin index \"%s\"",
         stack->blkno, RelationGetRelationName(btree->index));
 
    if (access == GIN_SHARE)
    {
        LockBuffer(stack->buffer, GIN_UNLOCK);
        LockBuffer(stack->buffer, GIN_EXCLUSIVE);
 
        if (!GinPageIsIncompleteSplit(BufferGetPage(stack->buffer)))
        {
            /*
             * Someone else already completed the split while we were not
             * holding the lock.
             */
            return;
        }
    }
 
    ginFinishSplit(btree, stack, false, buildStats);
}

References GinBtreeStack::blkno, GinBtreeStack::buffer, BufferGetPage(), DEBUG1, elog, GIN_EXCLUSIVE, GIN_SHARE, GIN_UNLOCK, ginFinishSplit(), GinPageIsIncompleteSplit, GinBtreeData::index, INJECTION_POINT, LockBuffer(), and RelationGetRelationName.

Referenced by ginFindLeafPage(), ginFindParents(), ginFinishSplit(), and ginInsertValue().

ginFinishSplit()

static void ginFinishSplit ( GinBtree  btree, GinBtreeStack *  stack, bool  freestack, GinStatsData *  buildStats  )

static

Definition at line 672 of file ginbtree.c.

{
    Page        page;
    bool        done;
    bool        first = true;
 
    /* this loop crawls up the stack until the insertion is complete */
    do
    {
        GinBtreeStack *parent = stack->parent;
        void       *insertdata;
        BlockNumber updateblkno;
 
#ifdef USE_INJECTION_POINTS
        if (GinPageIsLeaf(BufferGetPage(stack->buffer)))
            INJECTION_POINT("gin-leave-leaf-split-incomplete");
        else
            INJECTION_POINT("gin-leave-internal-split-incomplete");
#endif
 
        /* search parent to lock */
        LockBuffer(parent->buffer, GIN_EXCLUSIVE);
 
        /*
         * If the parent page was incompletely split, finish that split first,
         * then continue with the current one.
         *
         * Note: we have to finish *all* incomplete splits we encounter, even
         * if we have to move right. Otherwise we might choose as the target a
         * page that has no downlink in the parent, and splitting it further
         * would fail.
         */
        if (GinPageIsIncompleteSplit(BufferGetPage(parent->buffer)))
            ginFinishOldSplit(btree, parent, buildStats, GIN_EXCLUSIVE);
 
        /* move right if it's needed */
        page = BufferGetPage(parent->buffer);
        while ((parent->off = btree->findChildPtr(btree, page, stack->blkno, parent->off)) == InvalidOffsetNumber)
        {
            if (GinPageRightMost(page))
            {
                /*
                 * rightmost page, but we don't find parent, we should use
                 * plain search...
                 */
                LockBuffer(parent->buffer, GIN_UNLOCK);
                ginFindParents(btree, stack);
                parent = stack->parent;
                Assert(parent != NULL);
                break;
            }
 
            parent->buffer = ginStepRight(parent->buffer, btree->index, GIN_EXCLUSIVE);
            parent->blkno = BufferGetBlockNumber(parent->buffer);
            page = BufferGetPage(parent->buffer);
 
            if (GinPageIsIncompleteSplit(BufferGetPage(parent->buffer)))
                ginFinishOldSplit(btree, parent, buildStats, GIN_EXCLUSIVE);
        }
 
        /* insert the downlink */
        insertdata = btree->prepareDownlink(btree, stack->buffer);
        updateblkno = GinPageGetOpaque(BufferGetPage(stack->buffer))->rightlink;
        done = ginPlaceToPage(btree, parent,
                              insertdata, updateblkno,
                              stack->buffer, buildStats);
        pfree(insertdata);
 
        /*
         * If the caller requested to free the stack, unlock and release the
         * child buffer now. Otherwise keep it pinned and locked, but if we
         * have to recurse up the tree, we can unlock the upper pages, only
         * keeping the page at the bottom of the stack locked.
         */
        if (!first || freestack)
            LockBuffer(stack->buffer, GIN_UNLOCK);
        if (freestack)
        {
            ReleaseBuffer(stack->buffer);
            pfree(stack);
        }
        stack = parent;
 
        first = false;
    } while (!done);
 
    /* unlock the parent */
    LockBuffer(stack->buffer, GIN_UNLOCK);
 
    if (freestack)
        freeGinBtreeStack(stack);
}

References Assert, GinBtreeStack::blkno, GinBtreeStack::buffer, BufferGetBlockNumber(), BufferGetPage(), GinBtreeData::findChildPtr, freeGinBtreeStack(), GIN_EXCLUSIVE, GIN_UNLOCK, ginFindParents(), ginFinishOldSplit(), GinPageGetOpaque, GinPageIsIncompleteSplit, GinPageIsLeaf, GinPageRightMost, ginPlaceToPage(), ginStepRight(), GinBtreeData::index, INJECTION_POINT, InvalidOffsetNumber, LockBuffer(), GinBtreeStack::off, GinBtreeStack::parent, pfree(), GinBtreeData::prepareDownlink, and ReleaseBuffer().

Referenced by ginFinishOldSplit(), and ginInsertValue().

ginInsertValue()

void ginInsertValue	(	GinBtree	btree,
		GinBtreeStack *	stack,
		void *	insertdata,
		GinStatsData *	buildStats
	)

Definition at line 816 of file ginbtree.c.

{
    bool        done;
 
    /* If the leaf page was incompletely split, finish the split first */
    if (GinPageIsIncompleteSplit(BufferGetPage(stack->buffer)))
        ginFinishOldSplit(btree, stack, buildStats, GIN_EXCLUSIVE);
 
    done = ginPlaceToPage(btree, stack,
                          insertdata, InvalidBlockNumber,
                          InvalidBuffer, buildStats);
    if (done)
    {
        LockBuffer(stack->buffer, GIN_UNLOCK);
        freeGinBtreeStack(stack);
    }
    else
        ginFinishSplit(btree, stack, true, buildStats);
}

References GinBtreeStack::buffer, BufferGetPage(), freeGinBtreeStack(), GIN_EXCLUSIVE, GIN_UNLOCK, ginFinishOldSplit(), ginFinishSplit(), GinPageIsIncompleteSplit, ginPlaceToPage(), InvalidBlockNumber, InvalidBuffer, and LockBuffer().

Referenced by ginEntryInsert(), and ginInsertItemPointers().

ginPlaceToPage()

static bool ginPlaceToPage ( GinBtree  btree, GinBtreeStack *  stack, void *  insertdata, BlockNumber  updateblkno, Buffer  childbuf, GinStatsData *  buildStats  )

static

Definition at line 337 of file ginbtree.c.

{
    Page        page = BufferGetPage(stack->buffer);
    bool        result;
    GinPlaceToPageRC rc;
    uint16      xlflags = 0;
    Page        childpage = NULL;
    Page        newlpage = NULL,
                newrpage = NULL;
    void       *ptp_workspace = NULL;
    MemoryContext tmpCxt;
    MemoryContext oldCxt;
 
    /*
     * We do all the work of this function and its subfunctions in a temporary
     * memory context.  This avoids leakages and simplifies APIs, since some
     * subfunctions allocate storage that has to survive until we've finished
     * the WAL insertion.
     */
    tmpCxt = AllocSetContextCreate(CurrentMemoryContext,
                                   "ginPlaceToPage temporary context",
                                   ALLOCSET_DEFAULT_SIZES);
    oldCxt = MemoryContextSwitchTo(tmpCxt);
 
    if (GinPageIsData(page))
        xlflags |= GIN_INSERT_ISDATA;
    if (GinPageIsLeaf(page))
    {
        xlflags |= GIN_INSERT_ISLEAF;
        Assert(!BufferIsValid(childbuf));
        Assert(updateblkno == InvalidBlockNumber);
    }
    else
    {
        Assert(BufferIsValid(childbuf));
        Assert(updateblkno != InvalidBlockNumber);
        childpage = BufferGetPage(childbuf);
    }
 
    /*
     * See if the incoming tuple will fit on the page.  beginPlaceToPage will
     * decide if the page needs to be split, and will compute the split
     * contents if so.  See comments for beginPlaceToPage and execPlaceToPage
     * functions for more details of the API here.
     */
    rc = btree->beginPlaceToPage(btree, stack->buffer, stack,
                                 insertdata, updateblkno,
                                 &ptp_workspace,
                                 &newlpage, &newrpage);
 
    if (rc == GPTP_NO_WORK)
    {
        /* Nothing to do */
        result = true;
    }
    else if (rc == GPTP_INSERT)
    {
        /* It will fit, perform the insertion */
        START_CRIT_SECTION();
 
        if (RelationNeedsWAL(btree->index) && !btree->isBuild)
            XLogBeginInsert();
 
        /*
         * Perform the page update, dirty and register stack->buffer, and
         * register any extra WAL data.
         */
        btree->execPlaceToPage(btree, stack->buffer, stack,
                               insertdata, updateblkno, ptp_workspace);
 
        /* An insert to an internal page finishes the split of the child. */
        if (BufferIsValid(childbuf))
        {
            GinPageGetOpaque(childpage)->flags &= ~GIN_INCOMPLETE_SPLIT;
            MarkBufferDirty(childbuf);
            if (RelationNeedsWAL(btree->index) && !btree->isBuild)
                XLogRegisterBuffer(1, childbuf, REGBUF_STANDARD);
        }
 
        if (RelationNeedsWAL(btree->index) && !btree->isBuild)
        {
            XLogRecPtr  recptr;
            ginxlogInsert xlrec;
            BlockIdData childblknos[2];
 
            xlrec.flags = xlflags;
 
            XLogRegisterData((char *) &xlrec, sizeof(ginxlogInsert));
 
            /*
             * Log information about child if this was an insertion of a
             * downlink.
             */
            if (BufferIsValid(childbuf))
            {
                BlockIdSet(&childblknos[0], BufferGetBlockNumber(childbuf));
                BlockIdSet(&childblknos[1], GinPageGetOpaque(childpage)->rightlink);
                XLogRegisterData((char *) childblknos,
                                 sizeof(BlockIdData) * 2);
            }
 
            recptr = XLogInsert(RM_GIN_ID, XLOG_GIN_INSERT);
            PageSetLSN(page, recptr);
            if (BufferIsValid(childbuf))
                PageSetLSN(childpage, recptr);
        }
 
        END_CRIT_SECTION();
 
        /* Insertion is complete. */
        result = true;
    }
    else if (rc == GPTP_SPLIT)
    {
        /*
         * Didn't fit, need to split.  The split has been computed in newlpage
         * and newrpage, which are pointers to palloc'd pages, not associated
         * with buffers.  stack->buffer is not touched yet.
         */
        Buffer      rbuffer;
        BlockNumber savedRightLink;
        ginxlogSplit data;
        Buffer      lbuffer = InvalidBuffer;
        Page        newrootpg = NULL;
 
        /* Get a new index page to become the right page */
        rbuffer = GinNewBuffer(btree->index);
 
        /* During index build, count the new page */
        if (buildStats)
        {
            if (btree->isData)
                buildStats->nDataPages++;
            else
                buildStats->nEntryPages++;
        }
 
        savedRightLink = GinPageGetOpaque(page)->rightlink;
 
        /* Begin setting up WAL record */
        data.locator = btree->index->rd_locator;
        data.flags = xlflags;
        if (BufferIsValid(childbuf))
        {
            data.leftChildBlkno = BufferGetBlockNumber(childbuf);
            data.rightChildBlkno = GinPageGetOpaque(childpage)->rightlink;
        }
        else
            data.leftChildBlkno = data.rightChildBlkno = InvalidBlockNumber;
 
        if (stack->parent == NULL)
        {
            /*
             * splitting the root, so we need to allocate new left page and
             * place pointers to left and right page on root page.
             */
            lbuffer = GinNewBuffer(btree->index);
 
            /* During index build, count the new left page */
            if (buildStats)
            {
                if (btree->isData)
                    buildStats->nDataPages++;
                else
                    buildStats->nEntryPages++;
            }
 
            data.rrlink = InvalidBlockNumber;
            data.flags |= GIN_SPLIT_ROOT;
 
            GinPageGetOpaque(newrpage)->rightlink = InvalidBlockNumber;
            GinPageGetOpaque(newlpage)->rightlink = BufferGetBlockNumber(rbuffer);
 
            /*
             * Construct a new root page containing downlinks to the new left
             * and right pages.  (Do this in a temporary copy rather than
             * overwriting the original page directly, since we're not in the
             * critical section yet.)
             */
            newrootpg = PageGetTempPage(newrpage);
            GinInitPage(newrootpg, GinPageGetOpaque(newlpage)->flags & ~(GIN_LEAF | GIN_COMPRESSED), BLCKSZ);
 
            btree->fillRoot(btree, newrootpg,
                            BufferGetBlockNumber(lbuffer), newlpage,
                            BufferGetBlockNumber(rbuffer), newrpage);
 
            if (GinPageIsLeaf(BufferGetPage(stack->buffer)))
            {
 
                PredicateLockPageSplit(btree->index,
                                       BufferGetBlockNumber(stack->buffer),
                                       BufferGetBlockNumber(lbuffer));
 
                PredicateLockPageSplit(btree->index,
                                       BufferGetBlockNumber(stack->buffer),
                                       BufferGetBlockNumber(rbuffer));
            }
        }
        else
        {
            /* splitting a non-root page */
            data.rrlink = savedRightLink;
 
            GinPageGetOpaque(newrpage)->rightlink = savedRightLink;
            GinPageGetOpaque(newlpage)->flags |= GIN_INCOMPLETE_SPLIT;
            GinPageGetOpaque(newlpage)->rightlink = BufferGetBlockNumber(rbuffer);
 
            if (GinPageIsLeaf(BufferGetPage(stack->buffer)))
            {
 
                PredicateLockPageSplit(btree->index,
                                       BufferGetBlockNumber(stack->buffer),
                                       BufferGetBlockNumber(rbuffer));
            }
        }
 
        /*
         * OK, we have the new contents of the left page in a temporary copy
         * now (newlpage), and likewise for the new contents of the
         * newly-allocated right block. The original page is still unchanged.
         *
         * If this is a root split, we also have a temporary page containing
         * the new contents of the root.
         */
 
        START_CRIT_SECTION();
 
        MarkBufferDirty(rbuffer);
        MarkBufferDirty(stack->buffer);
 
        /*
         * Restore the temporary copies over the real buffers.
         */
        if (stack->parent == NULL)
        {
            /* Splitting the root, three pages to update */
            MarkBufferDirty(lbuffer);
            memcpy(page, newrootpg, BLCKSZ);
            memcpy(BufferGetPage(lbuffer), newlpage, BLCKSZ);
            memcpy(BufferGetPage(rbuffer), newrpage, BLCKSZ);
        }
        else
        {
            /* Normal split, only two pages to update */
            memcpy(page, newlpage, BLCKSZ);
            memcpy(BufferGetPage(rbuffer), newrpage, BLCKSZ);
        }
 
        /* We also clear childbuf's INCOMPLETE_SPLIT flag, if passed */
        if (BufferIsValid(childbuf))
        {
            GinPageGetOpaque(childpage)->flags &= ~GIN_INCOMPLETE_SPLIT;
            MarkBufferDirty(childbuf);
        }
 
        /* write WAL record */
        if (RelationNeedsWAL(btree->index) && !btree->isBuild)
        {
            XLogRecPtr  recptr;
 
            XLogBeginInsert();
 
            /*
             * We just take full page images of all the split pages. Splits
             * are uncommon enough that it's not worth complicating the code
             * to be more efficient.
             */
            if (stack->parent == NULL)
            {
                XLogRegisterBuffer(0, lbuffer, REGBUF_FORCE_IMAGE | REGBUF_STANDARD);
                XLogRegisterBuffer(1, rbuffer, REGBUF_FORCE_IMAGE | REGBUF_STANDARD);
                XLogRegisterBuffer(2, stack->buffer, REGBUF_FORCE_IMAGE | REGBUF_STANDARD);
            }
            else
            {
                XLogRegisterBuffer(0, stack->buffer, REGBUF_FORCE_IMAGE | REGBUF_STANDARD);
                XLogRegisterBuffer(1, rbuffer, REGBUF_FORCE_IMAGE | REGBUF_STANDARD);
            }
            if (BufferIsValid(childbuf))
                XLogRegisterBuffer(3, childbuf, REGBUF_STANDARD);
 
            XLogRegisterData((char *) &data, sizeof(ginxlogSplit));
 
            recptr = XLogInsert(RM_GIN_ID, XLOG_GIN_SPLIT);
 
            PageSetLSN(page, recptr);
            PageSetLSN(BufferGetPage(rbuffer), recptr);
            if (stack->parent == NULL)
                PageSetLSN(BufferGetPage(lbuffer), recptr);
            if (BufferIsValid(childbuf))
                PageSetLSN(childpage, recptr);
        }
        END_CRIT_SECTION();
 
        /*
         * We can release the locks/pins on the new pages now, but keep
         * stack->buffer locked.  childbuf doesn't get unlocked either.
         */
        UnlockReleaseBuffer(rbuffer);
        if (stack->parent == NULL)
            UnlockReleaseBuffer(lbuffer);
 
        /*
         * If we split the root, we're done. Otherwise the split is not
         * complete until the downlink for the new page has been inserted to
         * the parent.
         */
        result = (stack->parent == NULL);
    }
    else
    {
        elog(ERROR, "invalid return code from GIN beginPlaceToPage method: %d", rc);
        result = false;         /* keep compiler quiet */
    }
 
    /* Clean up temp context */
    MemoryContextSwitchTo(oldCxt);
    MemoryContextDelete(tmpCxt);
 
    return result;
}

References ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate, Assert, GinBtreeData::beginPlaceToPage, BlockIdSet(), GinBtreeStack::buffer, BufferGetBlockNumber(), BufferGetPage(), BufferIsValid(), CurrentMemoryContext, data, elog, END_CRIT_SECTION, ERROR, GinBtreeData::execPlaceToPage, GinBtreeData::fillRoot, ginxlogInsert::flags, GIN_COMPRESSED, GIN_INCOMPLETE_SPLIT, GIN_INSERT_ISDATA, GIN_INSERT_ISLEAF, GIN_LEAF, GIN_SPLIT_ROOT, GinInitPage(), GinNewBuffer(), GinPageGetOpaque, GinPageIsData, GinPageIsLeaf, GPTP_INSERT, GPTP_NO_WORK, GPTP_SPLIT, GinBtreeData::index, InvalidBlockNumber, InvalidBuffer, GinBtreeData::isBuild, GinBtreeData::isData, MarkBufferDirty(), MemoryContextDelete(), MemoryContextSwitchTo(), GinStatsData::nDataPages, GinStatsData::nEntryPages, PageGetTempPage(), PageSetLSN(), GinBtreeStack::parent, PredicateLockPageSplit(), RelationData::rd_locator, REGBUF_FORCE_IMAGE, REGBUF_STANDARD, RelationNeedsWAL, START_CRIT_SECTION, UnlockReleaseBuffer(), XLOG_GIN_INSERT, XLOG_GIN_SPLIT, XLogBeginInsert(), XLogInsert(), XLogRegisterBuffer(), and XLogRegisterData().

Referenced by ginFinishSplit(), and ginInsertValue().

ginStepRight()

Buffer ginStepRight	(	Buffer	buffer,
		Relation	index,
		int	lockmode
	)

Definition at line 177 of file ginbtree.c.

{
    Buffer      nextbuffer;
    Page        page = BufferGetPage(buffer);
    bool        isLeaf = GinPageIsLeaf(page);
    bool        isData = GinPageIsData(page);
    BlockNumber blkno = GinPageGetOpaque(page)->rightlink;
 
    nextbuffer = ReadBuffer(index, blkno);
    LockBuffer(nextbuffer, lockmode);
    UnlockReleaseBuffer(buffer);
 
    /* Sanity check that the page we stepped to is of similar kind. */
    page = BufferGetPage(nextbuffer);
    if (isLeaf != GinPageIsLeaf(page) || isData != GinPageIsData(page))
        elog(ERROR, "right sibling of GIN page is of different type");
 
    return nextbuffer;
}

References BufferGetPage(), elog, ERROR, GinPageGetOpaque, GinPageIsData, GinPageIsLeaf, LockBuffer(), ReadBuffer(), and UnlockReleaseBuffer().

Referenced by entryLoadMoreItems(), ginFindLeafPage(), ginFindParents(), ginFinishSplit(), moveRightIfItNeeded(), and scanPostingTree().

ginTraverseLock()

int ginTraverseLock	(	Buffer	buffer,
		bool	searchMode
	)

Definition at line 39 of file ginbtree.c.

{
    Page        page;
    int         access = GIN_SHARE;
 
    LockBuffer(buffer, GIN_SHARE);
    page = BufferGetPage(buffer);
    if (GinPageIsLeaf(page))
    {
        if (searchMode == false)
        {
            /* we should relock our page */
            LockBuffer(buffer, GIN_UNLOCK);
            LockBuffer(buffer, GIN_EXCLUSIVE);
 
            /* But root can become non-leaf during relock */
            if (!GinPageIsLeaf(page))
            {
                /* restore old lock type (very rare) */
                LockBuffer(buffer, GIN_UNLOCK);
                LockBuffer(buffer, GIN_SHARE);
            }
            else
                access = GIN_EXCLUSIVE;
        }
    }
 
    return access;
}

References BufferGetPage(), GIN_EXCLUSIVE, GIN_SHARE, GIN_UNLOCK, GinPageIsLeaf, and LockBuffer().

Referenced by ginFindLeafPage().