/src/postgres/src/backend/access/spgist/spgxlog.c

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/*-------------------------------------------------------------------------
 *
 * spgxlog.c
 *    WAL replay logic for SP-GiST
 *
 *
 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * IDENTIFICATION
 *       src/backend/access/spgist/spgxlog.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"

#include "access/bufmask.h"
#include "access/spgist_private.h"
#include "access/spgxlog.h"
#include "access/xlogutils.h"
#include "storage/standby.h"
#include "utils/memutils.h"


static MemoryContext opCtx;   /* working memory for operations */


/*
 * Prepare a dummy SpGistState, with just the minimum info needed for replay.
 *
 * At present, all we need is enough info to support spgFormDeadTuple(),
 * plus the isBuild flag.
 */
static void
fillFakeState(SpGistState *state, spgxlogState stateSrc)
{
  memset(state, 0, sizeof(*state));

  state->redirectXid = stateSrc.redirectXid;
  state->isBuild = stateSrc.isBuild;
  state->deadTupleStorage = palloc0(SGDTSIZE);
}

/*
 * Add a leaf tuple, or replace an existing placeholder tuple.  This is used
 * to replay SpGistPageAddNewItem() operations.  If the offset points at an
 * existing tuple, it had better be a placeholder tuple.
 */
static void
addOrReplaceTuple(Page page, Item tuple, int size, OffsetNumber offset)
{
  if (offset <= PageGetMaxOffsetNumber(page))
  {
    SpGistDeadTuple dt = (SpGistDeadTuple) PageGetItem(page,
                               PageGetItemId(page, offset));

    if (dt->tupstate != SPGIST_PLACEHOLDER)
      elog(ERROR, "SPGiST tuple to be replaced is not a placeholder");

    Assert(SpGistPageGetOpaque(page)->nPlaceholder > 0);
    SpGistPageGetOpaque(page)->nPlaceholder--;

    PageIndexTupleDelete(page, offset);
  }

  Assert(offset <= PageGetMaxOffsetNumber(page) + 1);

  if (PageAddItem(page, tuple, size, offset, false, false) != offset)
    elog(ERROR, "failed to add item of size %u to SPGiST index page",
       size);
}

static void
spgRedoAddLeaf(XLogReaderState *record)
{
  XLogRecPtr  lsn = record->EndRecPtr;
  char     *ptr = XLogRecGetData(record);
  spgxlogAddLeaf *xldata = (spgxlogAddLeaf *) ptr;
  char     *leafTuple;
  SpGistLeafTupleData leafTupleHdr;
  Buffer    buffer;
  Page    page;
  XLogRedoAction action;

  ptr += sizeof(spgxlogAddLeaf);
  leafTuple = ptr;
  /* the leaf tuple is unaligned, so make a copy to access its header */
  memcpy(&leafTupleHdr, leafTuple, sizeof(SpGistLeafTupleData));

  /*
   * In normal operation we would have both current and parent pages locked
   * simultaneously; but in WAL replay it should be safe to update the leaf
   * page before updating the parent.
   */
  if (xldata->newPage)
  {
    buffer = XLogInitBufferForRedo(record, 0);
    SpGistInitBuffer(buffer,
             SPGIST_LEAF | (xldata->storesNulls ? SPGIST_NULLS : 0));
    action = BLK_NEEDS_REDO;
  }
  else
    action = XLogReadBufferForRedo(record, 0, &buffer);

  if (action == BLK_NEEDS_REDO)
  {
    page = BufferGetPage(buffer);

    /* insert new tuple */
    if (xldata->offnumLeaf != xldata->offnumHeadLeaf)
    {
      /* normal cases, tuple was added by SpGistPageAddNewItem */
      addOrReplaceTuple(page, (Item) leafTuple, leafTupleHdr.size,
                xldata->offnumLeaf);

      /* update head tuple's chain link if needed */
      if (xldata->offnumHeadLeaf != InvalidOffsetNumber)
      {
        SpGistLeafTuple head;

        head = (SpGistLeafTuple) PageGetItem(page,
                           PageGetItemId(page, xldata->offnumHeadLeaf));
        Assert(SGLT_GET_NEXTOFFSET(head) == SGLT_GET_NEXTOFFSET(&leafTupleHdr));
        SGLT_SET_NEXTOFFSET(head, xldata->offnumLeaf);
      }
    }
    else
    {
      /* replacing a DEAD tuple */
      PageIndexTupleDelete(page, xldata->offnumLeaf);
      if (PageAddItem(page,
              (Item) leafTuple, leafTupleHdr.size,
              xldata->offnumLeaf, false, false) != xldata->offnumLeaf)
        elog(ERROR, "failed to add item of size %u to SPGiST index page",
           leafTupleHdr.size);
    }

    PageSetLSN(page, lsn);
    MarkBufferDirty(buffer);
  }
  if (BufferIsValid(buffer))
    UnlockReleaseBuffer(buffer);

  /* update parent downlink if necessary */
  if (xldata->offnumParent != InvalidOffsetNumber)
  {
    if (XLogReadBufferForRedo(record, 1, &buffer) == BLK_NEEDS_REDO)
    {
      SpGistInnerTuple tuple;
      BlockNumber blknoLeaf;

      XLogRecGetBlockTag(record, 0, NULL, NULL, &blknoLeaf);

      page = BufferGetPage(buffer);

      tuple = (SpGistInnerTuple) PageGetItem(page,
                           PageGetItemId(page, xldata->offnumParent));

      spgUpdateNodeLink(tuple, xldata->nodeI,
                blknoLeaf, xldata->offnumLeaf);

      PageSetLSN(page, lsn);
      MarkBufferDirty(buffer);
    }
    if (BufferIsValid(buffer))
      UnlockReleaseBuffer(buffer);
  }
}

static void
spgRedoMoveLeafs(XLogReaderState *record)
{
  XLogRecPtr  lsn = record->EndRecPtr;
  char     *ptr = XLogRecGetData(record);
  spgxlogMoveLeafs *xldata = (spgxlogMoveLeafs *) ptr;
  SpGistState state;
  OffsetNumber *toDelete;
  OffsetNumber *toInsert;
  int     nInsert;
  Buffer    buffer;
  Page    page;
  XLogRedoAction action;
  BlockNumber blknoDst;

  XLogRecGetBlockTag(record, 1, NULL, NULL, &blknoDst);

  fillFakeState(&state, xldata->stateSrc);

  nInsert = xldata->replaceDead ? 1 : xldata->nMoves + 1;

  ptr += SizeOfSpgxlogMoveLeafs;
  toDelete = (OffsetNumber *) ptr;
  ptr += sizeof(OffsetNumber) * xldata->nMoves;
  toInsert = (OffsetNumber *) ptr;
  ptr += sizeof(OffsetNumber) * nInsert;

  /* now ptr points to the list of leaf tuples */

  /*
   * In normal operation we would have all three pages (source, dest, and
   * parent) locked simultaneously; but in WAL replay it should be safe to
   * update them one at a time, as long as we do it in the right order.
   */

  /* Insert tuples on the dest page (do first, so redirect is valid) */
  if (xldata->newPage)
  {
    buffer = XLogInitBufferForRedo(record, 1);
    SpGistInitBuffer(buffer,
             SPGIST_LEAF | (xldata->storesNulls ? SPGIST_NULLS : 0));
    action = BLK_NEEDS_REDO;
  }
  else
    action = XLogReadBufferForRedo(record, 1, &buffer);

  if (action == BLK_NEEDS_REDO)
  {
    int     i;

    page = BufferGetPage(buffer);

    for (i = 0; i < nInsert; i++)
    {
      char     *leafTuple;
      SpGistLeafTupleData leafTupleHdr;

      /*
       * the tuples are not aligned, so must copy to access the size
       * field.
       */
      leafTuple = ptr;
      memcpy(&leafTupleHdr, leafTuple,
           sizeof(SpGistLeafTupleData));

      addOrReplaceTuple(page, (Item) leafTuple,
                leafTupleHdr.size, toInsert[i]);
      ptr += leafTupleHdr.size;
    }

    PageSetLSN(page, lsn);
    MarkBufferDirty(buffer);
  }
  if (BufferIsValid(buffer))
    UnlockReleaseBuffer(buffer);

  /* Delete tuples from the source page, inserting a redirection pointer */
  if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
  {
    page = BufferGetPage(buffer);

    spgPageIndexMultiDelete(&state, page, toDelete, xldata->nMoves,
                state.isBuild ? SPGIST_PLACEHOLDER : SPGIST_REDIRECT,
                SPGIST_PLACEHOLDER,
                blknoDst,
                toInsert[nInsert - 1]);

    PageSetLSN(page, lsn);
    MarkBufferDirty(buffer);
  }
  if (BufferIsValid(buffer))
    UnlockReleaseBuffer(buffer);

  /* And update the parent downlink */
  if (XLogReadBufferForRedo(record, 2, &buffer) == BLK_NEEDS_REDO)
  {
    SpGistInnerTuple tuple;

    page = BufferGetPage(buffer);

    tuple = (SpGistInnerTuple) PageGetItem(page,
                         PageGetItemId(page, xldata->offnumParent));

    spgUpdateNodeLink(tuple, xldata->nodeI,
              blknoDst, toInsert[nInsert - 1]);

    PageSetLSN(page, lsn);
    MarkBufferDirty(buffer);
  }
  if (BufferIsValid(buffer))
    UnlockReleaseBuffer(buffer);
}

static void
spgRedoAddNode(XLogReaderState *record)
{
  XLogRecPtr  lsn = record->EndRecPtr;
  char     *ptr = XLogRecGetData(record);
  spgxlogAddNode *xldata = (spgxlogAddNode *) ptr;
  char     *innerTuple;
  SpGistInnerTupleData innerTupleHdr;
  SpGistState state;
  Buffer    buffer;
  Page    page;
  XLogRedoAction action;

  ptr += sizeof(spgxlogAddNode);
  innerTuple = ptr;
  /* the tuple is unaligned, so make a copy to access its header */
  memcpy(&innerTupleHdr, innerTuple, sizeof(SpGistInnerTupleData));

  fillFakeState(&state, xldata->stateSrc);

  if (!XLogRecHasBlockRef(record, 1))
  {
    /* update in place */
    Assert(xldata->parentBlk == -1);
    if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
    {
      page = BufferGetPage(buffer);

      PageIndexTupleDelete(page, xldata->offnum);
      if (PageAddItem(page, (Item) innerTuple, innerTupleHdr.size,
              xldata->offnum,
              false, false) != xldata->offnum)
        elog(ERROR, "failed to add item of size %u to SPGiST index page",
           innerTupleHdr.size);

      PageSetLSN(page, lsn);
      MarkBufferDirty(buffer);
    }
    if (BufferIsValid(buffer))
      UnlockReleaseBuffer(buffer);
  }
  else
  {
    BlockNumber blkno;
    BlockNumber blknoNew;

    XLogRecGetBlockTag(record, 0, NULL, NULL, &blkno);
    XLogRecGetBlockTag(record, 1, NULL, NULL, &blknoNew);

    /*
     * In normal operation we would have all three pages (source, dest,
     * and parent) locked simultaneously; but in WAL replay it should be
     * safe to update them one at a time, as long as we do it in the right
     * order. We must insert the new tuple before replacing the old tuple
     * with the redirect tuple.
     */

    /* Install new tuple first so redirect is valid */
    if (xldata->newPage)
    {
      /* AddNode is not used for nulls pages */
      buffer = XLogInitBufferForRedo(record, 1);
      SpGistInitBuffer(buffer, 0);
      action = BLK_NEEDS_REDO;
    }
    else
      action = XLogReadBufferForRedo(record, 1, &buffer);
    if (action == BLK_NEEDS_REDO)
    {
      page = BufferGetPage(buffer);

      addOrReplaceTuple(page, (Item) innerTuple,
                innerTupleHdr.size, xldata->offnumNew);

      /*
       * If parent is in this same page, update it now.
       */
      if (xldata->parentBlk == 1)
      {
        SpGistInnerTuple parentTuple;

        parentTuple = (SpGistInnerTuple) PageGetItem(page,
                               PageGetItemId(page, xldata->offnumParent));

        spgUpdateNodeLink(parentTuple, xldata->nodeI,
                  blknoNew, xldata->offnumNew);
      }
      PageSetLSN(page, lsn);
      MarkBufferDirty(buffer);
    }
    if (BufferIsValid(buffer))
      UnlockReleaseBuffer(buffer);

    /* Delete old tuple, replacing it with redirect or placeholder tuple */
    if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
    {
      SpGistDeadTuple dt;

      page = BufferGetPage(buffer);

      if (state.isBuild)
        dt = spgFormDeadTuple(&state, SPGIST_PLACEHOLDER,
                    InvalidBlockNumber,
                    InvalidOffsetNumber);
      else
        dt = spgFormDeadTuple(&state, SPGIST_REDIRECT,
                    blknoNew,
                    xldata->offnumNew);

      PageIndexTupleDelete(page, xldata->offnum);
      if (PageAddItem(page, (Item) dt, dt->size,
              xldata->offnum,
              false, false) != xldata->offnum)
        elog(ERROR, "failed to add item of size %u to SPGiST index page",
           dt->size);

      if (state.isBuild)
        SpGistPageGetOpaque(page)->nPlaceholder++;
      else
        SpGistPageGetOpaque(page)->nRedirection++;

      /*
       * If parent is in this same page, update it now.
       */
      if (xldata->parentBlk == 0)
      {
        SpGistInnerTuple parentTuple;

        parentTuple = (SpGistInnerTuple) PageGetItem(page,
                               PageGetItemId(page, xldata->offnumParent));

        spgUpdateNodeLink(parentTuple, xldata->nodeI,
                  blknoNew, xldata->offnumNew);
      }
      PageSetLSN(page, lsn);
      MarkBufferDirty(buffer);
    }
    if (BufferIsValid(buffer))
      UnlockReleaseBuffer(buffer);

    /*
     * Update parent downlink (if we didn't do it as part of the source or
     * destination page update already).
     */
    if (xldata->parentBlk == 2)
    {
      if (XLogReadBufferForRedo(record, 2, &buffer) == BLK_NEEDS_REDO)
      {
        SpGistInnerTuple parentTuple;

        page = BufferGetPage(buffer);

        parentTuple = (SpGistInnerTuple) PageGetItem(page,
                               PageGetItemId(page, xldata->offnumParent));

        spgUpdateNodeLink(parentTuple, xldata->nodeI,
                  blknoNew, xldata->offnumNew);

        PageSetLSN(page, lsn);
        MarkBufferDirty(buffer);
      }
      if (BufferIsValid(buffer))
        UnlockReleaseBuffer(buffer);
    }
  }
}

static void
spgRedoSplitTuple(XLogReaderState *record)
{
  XLogRecPtr  lsn = record->EndRecPtr;
  char     *ptr = XLogRecGetData(record);
  spgxlogSplitTuple *xldata = (spgxlogSplitTuple *) ptr;
  char     *prefixTuple;
  SpGistInnerTupleData prefixTupleHdr;
  char     *postfixTuple;
  SpGistInnerTupleData postfixTupleHdr;
  Buffer    buffer;
  Page    page;
  XLogRedoAction action;

  ptr += sizeof(spgxlogSplitTuple);
  prefixTuple = ptr;
  /* the prefix tuple is unaligned, so make a copy to access its header */
  memcpy(&prefixTupleHdr, prefixTuple, sizeof(SpGistInnerTupleData));
  ptr += prefixTupleHdr.size;
  postfixTuple = ptr;
  /* postfix tuple is also unaligned */
  memcpy(&postfixTupleHdr, postfixTuple, sizeof(SpGistInnerTupleData));

  /*
   * In normal operation we would have both pages locked simultaneously; but
   * in WAL replay it should be safe to update them one at a time, as long
   * as we do it in the right order.
   */

  /* insert postfix tuple first to avoid dangling link */
  if (!xldata->postfixBlkSame)
  {
    if (xldata->newPage)
    {
      buffer = XLogInitBufferForRedo(record, 1);
      /* SplitTuple is not used for nulls pages */
      SpGistInitBuffer(buffer, 0);
      action = BLK_NEEDS_REDO;
    }
    else
      action = XLogReadBufferForRedo(record, 1, &buffer);
    if (action == BLK_NEEDS_REDO)
    {
      page = BufferGetPage(buffer);

      addOrReplaceTuple(page, (Item) postfixTuple,
                postfixTupleHdr.size, xldata->offnumPostfix);

      PageSetLSN(page, lsn);
      MarkBufferDirty(buffer);
    }
    if (BufferIsValid(buffer))
      UnlockReleaseBuffer(buffer);
  }

  /* now handle the original page */
  if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
  {
    page = BufferGetPage(buffer);

    PageIndexTupleDelete(page, xldata->offnumPrefix);
    if (PageAddItem(page, (Item) prefixTuple, prefixTupleHdr.size,
            xldata->offnumPrefix, false, false) != xldata->offnumPrefix)
      elog(ERROR, "failed to add item of size %u to SPGiST index page",
         prefixTupleHdr.size);

    if (xldata->postfixBlkSame)
      addOrReplaceTuple(page, (Item) postfixTuple,
                postfixTupleHdr.size,
                xldata->offnumPostfix);

    PageSetLSN(page, lsn);
    MarkBufferDirty(buffer);
  }
  if (BufferIsValid(buffer))
    UnlockReleaseBuffer(buffer);
}

static void
spgRedoPickSplit(XLogReaderState *record)
{
  XLogRecPtr  lsn = record->EndRecPtr;
  char     *ptr = XLogRecGetData(record);
  spgxlogPickSplit *xldata = (spgxlogPickSplit *) ptr;
  char     *innerTuple;
  SpGistInnerTupleData innerTupleHdr;
  SpGistState state;
  OffsetNumber *toDelete;
  OffsetNumber *toInsert;
  uint8    *leafPageSelect;
  Buffer    srcBuffer;
  Buffer    destBuffer;
  Buffer    innerBuffer;
  Page    srcPage;
  Page    destPage;
  Page    page;
  int     i;
  BlockNumber blknoInner;
  XLogRedoAction action;

  XLogRecGetBlockTag(record, 2, NULL, NULL, &blknoInner);

  fillFakeState(&state, xldata->stateSrc);

  ptr += SizeOfSpgxlogPickSplit;
  toDelete = (OffsetNumber *) ptr;
  ptr += sizeof(OffsetNumber) * xldata->nDelete;
  toInsert = (OffsetNumber *) ptr;
  ptr += sizeof(OffsetNumber) * xldata->nInsert;
  leafPageSelect = (uint8 *) ptr;
  ptr += sizeof(uint8) * xldata->nInsert;

  innerTuple = ptr;
  /* the inner tuple is unaligned, so make a copy to access its header */
  memcpy(&innerTupleHdr, innerTuple, sizeof(SpGistInnerTupleData));
  ptr += innerTupleHdr.size;

  /* now ptr points to the list of leaf tuples */

  if (xldata->isRootSplit)
  {
    /* when splitting root, we touch it only in the guise of new inner */
    srcBuffer = InvalidBuffer;
    srcPage = NULL;
  }
  else if (xldata->initSrc)
  {
    /* just re-init the source page */
    srcBuffer = XLogInitBufferForRedo(record, 0);
    srcPage = (Page) BufferGetPage(srcBuffer);

    SpGistInitBuffer(srcBuffer,
             SPGIST_LEAF | (xldata->storesNulls ? SPGIST_NULLS : 0));
    /* don't update LSN etc till we're done with it */
  }
  else
  {
    /*
     * Delete the specified tuples from source page.  (In case we're in
     * Hot Standby, we need to hold lock on the page till we're done
     * inserting leaf tuples and the new inner tuple, else the added
     * redirect tuple will be a dangling link.)
     */
    srcPage = NULL;
    if (XLogReadBufferForRedo(record, 0, &srcBuffer) == BLK_NEEDS_REDO)
    {
      srcPage = BufferGetPage(srcBuffer);

      /*
       * We have it a bit easier here than in doPickSplit(), because we
       * know the inner tuple's location already, so we can inject the
       * correct redirection tuple now.
       */
      if (!state.isBuild)
        spgPageIndexMultiDelete(&state, srcPage,
                    toDelete, xldata->nDelete,
                    SPGIST_REDIRECT,
                    SPGIST_PLACEHOLDER,
                    blknoInner,
                    xldata->offnumInner);
      else
        spgPageIndexMultiDelete(&state, srcPage,
                    toDelete, xldata->nDelete,
                    SPGIST_PLACEHOLDER,
                    SPGIST_PLACEHOLDER,
                    InvalidBlockNumber,
                    InvalidOffsetNumber);

      /* don't update LSN etc till we're done with it */
    }
  }

  /* try to access dest page if any */
  if (!XLogRecHasBlockRef(record, 1))
  {
    destBuffer = InvalidBuffer;
    destPage = NULL;
  }
  else if (xldata->initDest)
  {
    /* just re-init the dest page */
    destBuffer = XLogInitBufferForRedo(record, 1);
    destPage = (Page) BufferGetPage(destBuffer);

    SpGistInitBuffer(destBuffer,
             SPGIST_LEAF | (xldata->storesNulls ? SPGIST_NULLS : 0));
    /* don't update LSN etc till we're done with it */
  }
  else
  {
    /*
     * We could probably release the page lock immediately in the
     * full-page-image case, but for safety let's hold it till later.
     */
    if (XLogReadBufferForRedo(record, 1, &destBuffer) == BLK_NEEDS_REDO)
      destPage = (Page) BufferGetPage(destBuffer);
    else
      destPage = NULL; /* don't do any page updates */
  }

  /* restore leaf tuples to src and/or dest page */
  for (i = 0; i < xldata->nInsert; i++)
  {
    char     *leafTuple;
    SpGistLeafTupleData leafTupleHdr;

    /* the tuples are not aligned, so must copy to access the size field. */
    leafTuple = ptr;
    memcpy(&leafTupleHdr, leafTuple, sizeof(SpGistLeafTupleData));
    ptr += leafTupleHdr.size;

    page = leafPageSelect[i] ? destPage : srcPage;
    if (page == NULL)
      continue;     /* no need to touch this page */

    addOrReplaceTuple(page, (Item) leafTuple, leafTupleHdr.size,
              toInsert[i]);
  }

  /* Now update src and dest page LSNs if needed */
  if (srcPage != NULL)
  {
    PageSetLSN(srcPage, lsn);
    MarkBufferDirty(srcBuffer);
  }
  if (destPage != NULL)
  {
    PageSetLSN(destPage, lsn);
    MarkBufferDirty(destBuffer);
  }

  /* restore new inner tuple */
  if (xldata->initInner)
  {
    innerBuffer = XLogInitBufferForRedo(record, 2);
    SpGistInitBuffer(innerBuffer, (xldata->storesNulls ? SPGIST_NULLS : 0));
    action = BLK_NEEDS_REDO;
  }
  else
    action = XLogReadBufferForRedo(record, 2, &innerBuffer);

  if (action == BLK_NEEDS_REDO)
  {
    page = BufferGetPage(innerBuffer);

    addOrReplaceTuple(page, (Item) innerTuple, innerTupleHdr.size,
              xldata->offnumInner);

    /* if inner is also parent, update link while we're here */
    if (xldata->innerIsParent)
    {
      SpGistInnerTuple parent;

      parent = (SpGistInnerTuple) PageGetItem(page,
                          PageGetItemId(page, xldata->offnumParent));
      spgUpdateNodeLink(parent, xldata->nodeI,
                blknoInner, xldata->offnumInner);
    }

    PageSetLSN(page, lsn);
    MarkBufferDirty(innerBuffer);
  }
  if (BufferIsValid(innerBuffer))
    UnlockReleaseBuffer(innerBuffer);

  /*
   * Now we can release the leaf-page locks.  It's okay to do this before
   * updating the parent downlink.
   */
  if (BufferIsValid(srcBuffer))
    UnlockReleaseBuffer(srcBuffer);
  if (BufferIsValid(destBuffer))
    UnlockReleaseBuffer(destBuffer);

  /* update parent downlink, unless we did it above */
  if (XLogRecHasBlockRef(record, 3))
  {
    Buffer    parentBuffer;

    if (XLogReadBufferForRedo(record, 3, &parentBuffer) == BLK_NEEDS_REDO)
    {
      SpGistInnerTuple parent;

      page = BufferGetPage(parentBuffer);

      parent = (SpGistInnerTuple) PageGetItem(page,
                          PageGetItemId(page, xldata->offnumParent));
      spgUpdateNodeLink(parent, xldata->nodeI,
                blknoInner, xldata->offnumInner);

      PageSetLSN(page, lsn);
      MarkBufferDirty(parentBuffer);
    }
    if (BufferIsValid(parentBuffer))
      UnlockReleaseBuffer(parentBuffer);
  }
  else
    Assert(xldata->innerIsParent || xldata->isRootSplit);
}

static void
spgRedoVacuumLeaf(XLogReaderState *record)
{
  XLogRecPtr  lsn = record->EndRecPtr;
  char     *ptr = XLogRecGetData(record);
  spgxlogVacuumLeaf *xldata = (spgxlogVacuumLeaf *) ptr;
  OffsetNumber *toDead;
  OffsetNumber *toPlaceholder;
  OffsetNumber *moveSrc;
  OffsetNumber *moveDest;
  OffsetNumber *chainSrc;
  OffsetNumber *chainDest;
  SpGistState state;
  Buffer    buffer;
  Page    page;
  int     i;

  fillFakeState(&state, xldata->stateSrc);

  ptr += SizeOfSpgxlogVacuumLeaf;
  toDead = (OffsetNumber *) ptr;
  ptr += sizeof(OffsetNumber) * xldata->nDead;
  toPlaceholder = (OffsetNumber *) ptr;
  ptr += sizeof(OffsetNumber) * xldata->nPlaceholder;
  moveSrc = (OffsetNumber *) ptr;
  ptr += sizeof(OffsetNumber) * xldata->nMove;
  moveDest = (OffsetNumber *) ptr;
  ptr += sizeof(OffsetNumber) * xldata->nMove;
  chainSrc = (OffsetNumber *) ptr;
  ptr += sizeof(OffsetNumber) * xldata->nChain;
  chainDest = (OffsetNumber *) ptr;

  if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
  {
    page = BufferGetPage(buffer);

    spgPageIndexMultiDelete(&state, page,
                toDead, xldata->nDead,
                SPGIST_DEAD, SPGIST_DEAD,
                InvalidBlockNumber,
                InvalidOffsetNumber);

    spgPageIndexMultiDelete(&state, page,
                toPlaceholder, xldata->nPlaceholder,
                SPGIST_PLACEHOLDER, SPGIST_PLACEHOLDER,
                InvalidBlockNumber,
                InvalidOffsetNumber);

    /* see comments in vacuumLeafPage() */
    for (i = 0; i < xldata->nMove; i++)
    {
      ItemId    idSrc = PageGetItemId(page, moveSrc[i]);
      ItemId    idDest = PageGetItemId(page, moveDest[i]);
      ItemIdData  tmp;

      tmp = *idSrc;
      *idSrc = *idDest;
      *idDest = tmp;
    }

    spgPageIndexMultiDelete(&state, page,
                moveSrc, xldata->nMove,
                SPGIST_PLACEHOLDER, SPGIST_PLACEHOLDER,
                InvalidBlockNumber,
                InvalidOffsetNumber);

    for (i = 0; i < xldata->nChain; i++)
    {
      SpGistLeafTuple lt;

      lt = (SpGistLeafTuple) PageGetItem(page,
                         PageGetItemId(page, chainSrc[i]));
      Assert(lt->tupstate == SPGIST_LIVE);
      SGLT_SET_NEXTOFFSET(lt, chainDest[i]);
    }

    PageSetLSN(page, lsn);
    MarkBufferDirty(buffer);
  }
  if (BufferIsValid(buffer))
    UnlockReleaseBuffer(buffer);
}

static void
spgRedoVacuumRoot(XLogReaderState *record)
{
  XLogRecPtr  lsn = record->EndRecPtr;
  char     *ptr = XLogRecGetData(record);
  spgxlogVacuumRoot *xldata = (spgxlogVacuumRoot *) ptr;
  OffsetNumber *toDelete;
  Buffer    buffer;
  Page    page;

  toDelete = xldata->offsets;

  if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
  {
    page = BufferGetPage(buffer);

    /* The tuple numbers are in order */
    PageIndexMultiDelete(page, toDelete, xldata->nDelete);

    PageSetLSN(page, lsn);
    MarkBufferDirty(buffer);
  }
  if (BufferIsValid(buffer))
    UnlockReleaseBuffer(buffer);
}

static void
spgRedoVacuumRedirect(XLogReaderState *record)
{
  XLogRecPtr  lsn = record->EndRecPtr;
  char     *ptr = XLogRecGetData(record);
  spgxlogVacuumRedirect *xldata = (spgxlogVacuumRedirect *) ptr;
  OffsetNumber *itemToPlaceholder;
  Buffer    buffer;

  itemToPlaceholder = xldata->offsets;

  /*
   * If any redirection tuples are being removed, make sure there are no
   * live Hot Standby transactions that might need to see them.
   */
  if (InHotStandby)
  {
    RelFileLocator locator;

    XLogRecGetBlockTag(record, 0, &locator, NULL, NULL);
    ResolveRecoveryConflictWithSnapshot(xldata->snapshotConflictHorizon,
                      xldata->isCatalogRel,
                      locator);
  }

  if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
  {
    Page    page = BufferGetPage(buffer);
    SpGistPageOpaque opaque = SpGistPageGetOpaque(page);
    int     i;

    /* Convert redirect pointers to plain placeholders */
    for (i = 0; i < xldata->nToPlaceholder; i++)
    {
      SpGistDeadTuple dt;

      dt = (SpGistDeadTuple) PageGetItem(page,
                         PageGetItemId(page, itemToPlaceholder[i]));
      Assert(dt->tupstate == SPGIST_REDIRECT);
      dt->tupstate = SPGIST_PLACEHOLDER;
      ItemPointerSetInvalid(&dt->pointer);
    }

    Assert(opaque->nRedirection >= xldata->nToPlaceholder);
    opaque->nRedirection -= xldata->nToPlaceholder;
    opaque->nPlaceholder += xldata->nToPlaceholder;

    /* Remove placeholder tuples at end of page */
    if (xldata->firstPlaceholder != InvalidOffsetNumber)
    {
      int     max = PageGetMaxOffsetNumber(page);
      OffsetNumber *toDelete;

      toDelete = palloc(sizeof(OffsetNumber) * max);

      for (i = xldata->firstPlaceholder; i <= max; i++)
        toDelete[i - xldata->firstPlaceholder] = i;

      i = max - xldata->firstPlaceholder + 1;
      Assert(opaque->nPlaceholder >= i);
      opaque->nPlaceholder -= i;

      /* The array is sorted, so can use PageIndexMultiDelete */
      PageIndexMultiDelete(page, toDelete, i);

      pfree(toDelete);
    }

    PageSetLSN(page, lsn);
    MarkBufferDirty(buffer);
  }
  if (BufferIsValid(buffer))
    UnlockReleaseBuffer(buffer);
}

void
spg_redo(XLogReaderState *record)
{
  uint8   info = XLogRecGetInfo(record) & ~XLR_INFO_MASK;
  MemoryContext oldCxt;

  oldCxt = MemoryContextSwitchTo(opCtx);
  switch (info)
  {
    case XLOG_SPGIST_ADD_LEAF:
      spgRedoAddLeaf(record);
      break;
    case XLOG_SPGIST_MOVE_LEAFS:
      spgRedoMoveLeafs(record);
      break;
    case XLOG_SPGIST_ADD_NODE:
      spgRedoAddNode(record);
      break;
    case XLOG_SPGIST_SPLIT_TUPLE:
      spgRedoSplitTuple(record);
      break;
    case XLOG_SPGIST_PICKSPLIT:
      spgRedoPickSplit(record);
      break;
    case XLOG_SPGIST_VACUUM_LEAF:
      spgRedoVacuumLeaf(record);
      break;
    case XLOG_SPGIST_VACUUM_ROOT:
      spgRedoVacuumRoot(record);
      break;
    case XLOG_SPGIST_VACUUM_REDIRECT:
      spgRedoVacuumRedirect(record);
      break;
    default:
      elog(PANIC, "spg_redo: unknown op code %u", info);
  }

  MemoryContextSwitchTo(oldCxt);
  MemoryContextReset(opCtx);
}

void
spg_xlog_startup(void)
{
  opCtx = AllocSetContextCreate(CurrentMemoryContext,
                  "SP-GiST temporary context",
                  ALLOCSET_DEFAULT_SIZES);
}

void
spg_xlog_cleanup(void)
{
  MemoryContextDelete(opCtx);
  opCtx = NULL;
}

/*
 * Mask a SpGist page before performing consistency checks on it.
 */
void
spg_mask(char *pagedata, BlockNumber blkno)
{
  Page    page = (Page) pagedata;
  PageHeader  pagehdr = (PageHeader) page;

  mask_page_lsn_and_checksum(page);

  mask_page_hint_bits(page);

  /*
   * Mask the unused space, but only if the page's pd_lower appears to have
   * been set correctly.
   */
  if (pagehdr->pd_lower >= SizeOfPageHeaderData)
    mask_unused_space(page);
}

Coverage Report

Created: 2025-06-13 06:06