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Prototype split build
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@x4m
x4m committed Dec 21, 2021
1 parent 0e6e7f0 commit 0f2ed5f
Showing 1 changed file with 138 additions and 36 deletions.
174 changes: 138 additions & 36 deletions src/backend/access/gist/gistbuild.c
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Expand Up @@ -120,7 +120,11 @@ typedef struct
*/
typedef struct GistSortedBuildPageState
{
Page page;
Page pages_candidates[128];
Page union_tuples;
int pages_count;
int ages[128];
int current_age;
struct GistSortedBuildPageState *parent; /* Upper level, if any */
} GistSortedBuildPageState;

Expand All @@ -134,7 +138,9 @@ static void gist_indexsortbuild_pagestate_add(GISTBuildState *state,
GistSortedBuildPageState *pagestate,
IndexTuple itup);
static void gist_indexsortbuild_pagestate_flush(GISTBuildState *state,
GistSortedBuildPageState *pagestate);
GistSortedBuildPageState *pagestate, int index);
static void gist_indexsortbuild_pagestate_check_flush(GISTBuildState *state,
GistSortedBuildPageState *pagestate, int max_pages_left);
static void gist_indexsortbuild_flush_ready_pages(GISTBuildState *state);

static void gistInitBuffering(GISTBuildState *buildstate);
Expand Down Expand Up @@ -415,11 +421,15 @@ gist_indexsortbuild(GISTBuildState *state)
state->pages_written++;

/* Allocate a temporary buffer for the first leaf page. */
leafstate = palloc(sizeof(GistSortedBuildPageState));
leafstate->page = page;
leafstate = palloc0(sizeof(GistSortedBuildPageState));
leafstate->pages_candidates[0] = page;
leafstate->pages_count = 1;
leafstate->parent = NULL;
gistinitpage(page, F_LEAF);

leafstate->union_tuples = palloc0(BLCKSZ);
gistinitpage(leafstate->union_tuples, 0);

/*
* Fill index pages with tuples in the sorted order.
*/
Expand All @@ -435,29 +445,29 @@ gist_indexsortbuild(GISTBuildState *state)
* Keep in mind that flush can build a new root.
*/
pagestate = leafstate;
while (pagestate->parent != NULL)
while (pagestate->pages_count != 1)
{
GistSortedBuildPageState *parent;

gist_indexsortbuild_pagestate_flush(state, pagestate);
gist_indexsortbuild_pagestate_check_flush(state, pagestate, 0);
parent = pagestate->parent;
pfree(pagestate->page);
//pfree(pagestate->page);
pfree(pagestate);
pagestate = parent;
}

gist_indexsortbuild_flush_ready_pages(state);

/* Write out the root */
PageSetLSN(pagestate->page, GistBuildLSN);
PageSetChecksumInplace(pagestate->page, GIST_ROOT_BLKNO);
PageSetLSN(pagestate->pages_candidates[0], GistBuildLSN);
PageSetChecksumInplace(pagestate->pages_candidates[0], GIST_ROOT_BLKNO);
smgrwrite(RelationGetSmgr(state->indexrel), MAIN_FORKNUM, GIST_ROOT_BLKNO,
pagestate->page, true);
pagestate->pages_candidates[0], true);
if (RelationNeedsWAL(state->indexrel))
log_newpage(&state->indexrel->rd_node, MAIN_FORKNUM, GIST_ROOT_BLKNO,
pagestate->page, true);
pagestate->pages_candidates[0], true);

pfree(pagestate->page);
//pfree(pagestate->page);
pfree(pagestate);
}

Expand All @@ -470,27 +480,113 @@ gist_indexsortbuild_pagestate_add(GISTBuildState *state,
GistSortedBuildPageState *pagestate,
IndexTuple itup)
{
Size sizeNeeded;
if (PageIsEmpty(pagestate->union_tuples))
{
Assert(pagestate->pages_count == 1);
gistfillbuffer(pagestate->pages_candidates[0], &itup, 1, InvalidOffsetNumber);
gistfillbuffer(pagestate->union_tuples, &itup, 1, InvalidOffsetNumber);
return;
}

do
{
int idx = gistchoose(state->indexrel, pagestate->union_tuples, itup, state->giststate) - FirstOffsetNumber;
Page target = pagestate->pages_candidates[idx];
uint32 flags = GistPageIsLeaf(target)? F_LEAF : 0;
Size sizeNeeded;
int i;

/* Does the tuple fit? If not, split */
sizeNeeded = IndexTupleSize(itup) + sizeof(ItemIdData) + state->freespace;
if (PageGetFreeSpace(target) < sizeNeeded)
{
int tlen;
IndexTuple *itvec = gistextractpage(target, &tlen);
SplitedPageLayout *dist = gistSplit(state->indexrel, target, itvec, tlen, state->giststate);
memset(target, 0 , BLCKSZ);
gistinitpage(target, flags);

char *data = (char *) (dist->list);

for (i = 0; i < dist->block.num; i++)
{
IndexTuple thistup = (IndexTuple) data;

if (PageAddItem(target, (Item) data, IndexTupleSize(thistup), i + FirstOffsetNumber, false, false) == InvalidOffsetNumber)
elog(ERROR, "failed to add item to index page in \"%s\"", RelationGetRelationName(state->indexrel));

data += IndexTupleSize(thistup);
}
PageIndexTupleOverwrite(pagestate->union_tuples, idx + FirstOffsetNumber, (Item)dist->itup, IndexTupleSize(dist->itup));
dist = dist->next;

for (;dist != NULL; dist = dist->next)
{
data = (char *) (dist->list);
target = pagestate->pages_candidates[pagestate->pages_count] = palloc0(BLCKSZ);
pagestate->ages[pagestate->pages_count] = pagestate->current_age;
gistinitpage(target, flags);
for (i = 0; i < dist->block.num; i++)
{
IndexTuple thistup = (IndexTuple) data;

if (PageAddItem(target, (Item) data, IndexTupleSize(thistup), i + FirstOffsetNumber, false, false) == InvalidOffsetNumber)
elog(ERROR, "failed to add item to index page in \"%s\"", RelationGetRelationName(state->indexrel));

data += IndexTupleSize(thistup);
}
gistfillbuffer(pagestate->union_tuples, &dist->itup, 1, InvalidOffsetNumber);
pagestate->pages_count++;
}

continue;
}

gistfillbuffer(pagestate->pages_candidates[idx], &itup, 1, InvalidOffsetNumber);
pagestate->ages[idx] = pagestate->current_age++;

/* Does the tuple fit? If not, flush */
sizeNeeded = IndexTupleSize(itup) + sizeof(ItemIdData) + state->freespace;
if (PageGetFreeSpace(pagestate->page) < sizeNeeded)
gist_indexsortbuild_pagestate_flush(state, pagestate);
IndexTuple union_tuple = (IndexTuple) PageGetItem(pagestate->union_tuples, PageGetItemId(pagestate->union_tuples, idx + FirstOffsetNumber));
IndexTuple newtup = gistgetadjusted(state->indexrel, union_tuple, itup, state->giststate);
if (newtup)
{
PageIndexTupleOverwrite(pagestate->union_tuples, idx + FirstOffsetNumber, (Item)newtup, IndexTupleSize(newtup));
}
break;
} while(true);

gistfillbuffer(pagestate->page, &itup, 1, InvalidOffsetNumber);
gist_indexsortbuild_pagestate_check_flush(state, pagestate, 4);
}

static void
gist_indexsortbuild_pagestate_check_flush(GISTBuildState *state,
GistSortedBuildPageState *pagestate, int max_pages_left)
{
while(pagestate->pages_count > max_pages_left)
{
int i;
int min_age = PG_INT32_MAX;
int victim = -1;
for (i = 0; i < pagestate->pages_count; i++)
{
if (pagestate->ages[i] < min_age)
{
victim = i;
min_age = pagestate->ages[i];
}
}
gist_indexsortbuild_pagestate_flush(state, pagestate, victim);
}
}

static void
gist_indexsortbuild_pagestate_flush(GISTBuildState *state,
GistSortedBuildPageState *pagestate)
GistSortedBuildPageState *pagestate, int index)
{
GistSortedBuildPageState *parent;
IndexTuple *itvec;
IndexTuple union_tuple;
int vect_len;
bool isleaf;
BlockNumber blkno;
MemoryContext oldCtx;
int i;

/* check once per page */
CHECK_FOR_INTERRUPTS();
Expand All @@ -505,20 +601,16 @@ gist_indexsortbuild_pagestate_flush(GISTBuildState *state,
*/
blkno = state->pages_allocated++;
state->ready_blknos[state->ready_num_pages] = blkno;
state->ready_pages[state->ready_num_pages] = pagestate->page;
state->ready_pages[state->ready_num_pages] = pagestate->pages_candidates[index];
state->ready_num_pages++;

isleaf = GistPageIsLeaf(pagestate->page);
isleaf = GistPageIsLeaf(pagestate->pages_candidates[index]);

/*
* Form a downlink tuple to represent all the tuples on the page.
*/
oldCtx = MemoryContextSwitchTo(state->giststate->tempCxt);
itvec = gistextractpage(pagestate->page, &vect_len);
union_tuple = gistunion(state->indexrel, itvec, vect_len,
state->giststate);
union_tuple = (IndexTuple) PageGetItem(pagestate->union_tuples, PageGetItemId(pagestate->union_tuples, index + FirstOffsetNumber));
ItemPointerSetBlockNumber(&(union_tuple->t_tid), blkno);
MemoryContextSwitchTo(oldCtx);

/*
* Insert the downlink to the parent page. If this was the root, create a
Expand All @@ -527,18 +619,28 @@ gist_indexsortbuild_pagestate_flush(GISTBuildState *state,
parent = pagestate->parent;
if (parent == NULL)
{
parent = palloc(sizeof(GistSortedBuildPageState));
parent->page = (Page) palloc(BLCKSZ);
parent = palloc0(sizeof(GistSortedBuildPageState));
parent->pages_candidates[0] = (Page) palloc(BLCKSZ);
parent->pages_count = 1;
parent->parent = NULL;
gistinitpage(parent->page, 0);
gistinitpage(parent->pages_candidates[0], 0);

parent->union_tuples = palloc0(BLCKSZ);
gistinitpage(parent->union_tuples, 0);

pagestate->parent = parent;
}
gist_indexsortbuild_pagestate_add(state, parent, union_tuple);

/* Re-initialize the page buffer for next page on this level. */
pagestate->page = palloc(BLCKSZ);
gistinitpage(pagestate->page, isleaf ? F_LEAF : 0);
/* Cleanup page from leftovers */
for (i = index + 1; i < pagestate->pages_count; i++)
{
pagestate->ages[i - 1] = pagestate->ages[i];
pagestate->pages_candidates[i - 1] = pagestate->pages_candidates[i];
}
pagestate->pages_count--;

PageIndexTupleDelete(pagestate->union_tuples, index + FirstOffsetNumber);

/*
* Set the right link to point to the previous page. This is just for
Expand All @@ -551,7 +653,7 @@ gist_indexsortbuild_pagestate_flush(GISTBuildState *state,
* right-links form a chain through all the pages in the same level, the
* order doesn't matter.
*/
GistPageGetOpaque(pagestate->page)->rightlink = blkno;
//GistPageGetOpaque(pagestate->page)->rightlink = blkno;
}

static void
Expand Down

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