static Size FreePageBtreeSearchLeaf(FreePageBtree *btp, Size first_page);
static FreePageBtree *FreePageBtreeSplitPage(FreePageManager *fpm,
FreePageBtree *btp);
+static void FreePageBtreeUpdateParentPointers(char *base, FreePageBtree *btp);
static void FreePageManagerDumpBtree(FreePageManager *fpm, FreePageBtree *btp,
- int level, StringInfo buf);
+ FreePageBtree *parent, int level, StringInfo buf);
static void FreePageManagerDumpSpans(FreePageManager *fpm,
FreePageSpanLeader *span, Size expected_pages,
StringInfo buf);
static bool FreePageManagerGetInternal(FreePageManager *fpm, Size npages,
Size *first_page);
+static bool FreePageManagerPutInternal(FreePageManager *fpm, Size first_page,
+ Size npages, bool soft);
static void FreePagePopSpanLeader(FreePageManager *fpm, Size pageno);
static void FreePagePushSpanLeader(FreePageManager *fpm, Size first_page,
Size npages);
-static bool FreePageManagerPutInternal(FreePageManager *fpm, Size first_page,
- Size npages, bool soft);
/*
* Initialize a new, empty free page manager.
appendStringInfo(&buf, "btree depth %u:\n", fpm->btree_depth);
root = relptr_access(base, fpm->btree_root);
- FreePageManagerDumpBtree(fpm, root, 0, &buf);
+ FreePageManagerDumpBtree(fpm, root, NULL, 0, &buf);
}
else if (fpm->singleton_npages > 0)
{
if (np != NULL && btp->hdr.nused + np->hdr.nused <= max)
{
if (btp->hdr.magic == FREE_PAGE_LEAF_MAGIC)
+ {
memcpy(&btp->u.leaf_key[btp->hdr.nused], &np->u.leaf_key[0],
sizeof(FreePageBtreeLeafKey) * np->hdr.nused);
+ btp->hdr.nused += np->hdr.nused;
+ }
else
+ {
memcpy(&btp->u.internal_key[btp->hdr.nused], &np->u.internal_key[0],
sizeof(FreePageBtreeInternalKey) * np->hdr.nused);
- btp->hdr.nused += np->hdr.nused;
+ btp->hdr.nused += np->hdr.nused;
+ FreePageBtreeUpdateParentPointers(base, btp);
+ }
FreePageBtreeRemovePage(fpm, np);
return;
}
if (np != NULL && btp->hdr.nused + np->hdr.nused <= max)
{
if (btp->hdr.magic == FREE_PAGE_LEAF_MAGIC)
+ {
memcpy(&np->u.leaf_key[np->hdr.nused], &btp->u.leaf_key[0],
sizeof(FreePageBtreeLeafKey) * btp->hdr.nused);
+ np->hdr.nused += btp->hdr.nused;
+ }
else
+ {
memcpy(&np->u.internal_key[np->hdr.nused], &btp->u.internal_key[0],
sizeof(FreePageBtreeInternalKey) * btp->hdr.nused);
+ np->hdr.nused += btp->hdr.nused;
+ FreePageBtreeUpdateParentPointers(base, np);
+ }
np->hdr.nused += btp->hdr.nused;
FreePageBtreeRemovePage(fpm, btp);
return;
Size first_page;
Size index;
+ first_page = FreePageBtreeFirstKey(p);
p = relptr_access(base, p->hdr.parent);
if (p == NULL)
return NULL; /* we were passed the rightmost page */
- first_page = FreePageBtreeFirstKey(p);
index = FreePageBtreeSearchInternal(p, first_page);
if (index > 0)
{
+ Assert(p->u.internal_key[index].first_page == first_page);
p = relptr_access(base, p->u.internal_key[index - 1].child);
break;
}
Size first_page;
Size index;
+ first_page = FreePageBtreeFirstKey(p);
p = relptr_access(base, p->hdr.parent);
if (p == NULL)
return NULL; /* we were passed the rightmost page */
- first_page = FreePageBtreeFirstKey(p);
index = FreePageBtreeSearchInternal(p, first_page);
if (index < p->hdr.nused - 1)
{
+ Assert(p->u.internal_key[index].first_page == first_page);
p = relptr_access(base, p->u.internal_key[index + 1].child);
break;
}
{
char *base = fpm_segment_base(fpm);
FreePageBtree *parent;
+ Size index;
+ Size first_page;
for (;;)
{
- Size index;
- Size first_page;
-
/* Find parent page. */
parent = relptr_access(base, btp->hdr.parent);
if (parent == NULL)
return;
}
- /* Find and remove the downlink. */
- first_page = FreePageBtreeFirstKey(btp);
- if (parent->hdr.magic == FREE_PAGE_LEAF_MAGIC)
- {
- index = FreePageBtreeSearchLeaf(parent, first_page);
- Assert(index < parent->hdr.nused);
- if (index < parent->hdr.nused - 1)
- memmove(&parent->u.leaf_key[index],
- &parent->u.leaf_key[index + 1],
- sizeof(FreePageBtreeLeafKey)
- * (parent->hdr.nused - index - 1));
- }
- else
- {
- index = FreePageBtreeSearchInternal(parent, first_page);
- Assert(index < parent->hdr.nused);
- if (index < parent->hdr.nused - 1)
- memmove(&parent->u.internal_key[index],
- &parent->u.internal_key[index + 1],
- sizeof(FreePageBtreeInternalKey)
- * (btp->hdr.nused - index - 1));
- }
- parent->hdr.nused--;
-
- /* Recycle target page. */
- FreePageBtreeRecycle(fpm, fpm_pointer_to_page(base, btp));
-
/*
- * If the parent has become empty in turn, we must loop around and
- * remove it in turn. If not, we can break out of the loop, but must
- * adjust ancestor keys if we updated the first key on the page.
+ * If the parent contains only one item, we need to remove it as
+ * well.
*/
- if (parent->hdr.nused > 0)
- {
- if (index == 0)
- FreePageBtreeAdjustAncestorKeys(fpm, parent);
+ if (parent->hdr.nused > 1)
break;
- }
+ FreePageBtreeRecycle(fpm, fpm_pointer_to_page(base, btp));
btp = parent;
}
- /* Consider whether to consolidate the parent with a sibings. */
+ /* Find and remove the downlink. */
+ first_page = FreePageBtreeFirstKey(btp);
+ if (parent->hdr.magic == FREE_PAGE_LEAF_MAGIC)
+ {
+ index = FreePageBtreeSearchLeaf(parent, first_page);
+ Assert(index < parent->hdr.nused);
+ if (index < parent->hdr.nused - 1)
+ memmove(&parent->u.leaf_key[index],
+ &parent->u.leaf_key[index + 1],
+ sizeof(FreePageBtreeLeafKey)
+ * (parent->hdr.nused - index - 1));
+ }
+ else
+ {
+ index = FreePageBtreeSearchInternal(parent, first_page);
+ Assert(index < parent->hdr.nused);
+ if (index < parent->hdr.nused - 1)
+ memmove(&parent->u.internal_key[index],
+ &parent->u.internal_key[index + 1],
+ sizeof(FreePageBtreeInternalKey)
+ * (parent->hdr.nused - index - 1));
+ }
+ parent->hdr.nused--;
+ Assert(parent->hdr.nused > 0);
+
+ /* Recycle the page. */
+ FreePageBtreeRecycle(fpm, fpm_pointer_to_page(base, btp));
+
+ /* Adjust ancestor keys if needed. */
+ if (index == 0)
+ FreePageBtreeAdjustAncestorKeys(fpm, parent);
+
+ /* Consider whether to consolidate the parent with a sibling. */
FreePageBtreeConsolidate(fpm, parent);
}
else
result->split_pages = 0;
+ /* Descend to appropriate child page. */
+ Assert(index < btp->hdr.nused);
child = relptr_access(base, btp->u.internal_key[index].child);
- Assert(relptr_access(base, child->hdr.parent) == btp);
+ if (relptr_access(base, child->hdr.parent) != btp)
+ {
+ elog(LOG, "btp = %zu, child = %zu, child parent = %zu",
+ fpm_pointer_to_page(base, btp),
+ fpm_pointer_to_page(base, child),
+ fpm_pointer_to_page(base, relptr_access(base, child->hdr.parent)));
+ elog(FATAL, "%s", FreePageManagerDump(fpm));
+ }
btp = child;
}
memcpy(&newsibling->u.internal_key,
&btp->u.internal_key[btp->hdr.nused],
sizeof(FreePageBtreeInternalKey) * newsibling->hdr.nused);
+ FreePageBtreeUpdateParentPointers(fpm_segment_base(fpm), newsibling);
}
return newsibling;
}
+/*
+ * When internal pages are split or merged, the parent pointers of their
+ * children must be updated.
+ */
+static void
+FreePageBtreeUpdateParentPointers(char *base, FreePageBtree *btp)
+{
+ Size i;
+
+ Assert(btp->hdr.magic == FREE_PAGE_INTERNAL_MAGIC);
+ for (i = 0; i < btp->hdr.nused; ++i)
+ {
+ FreePageBtree *child;
+
+ child = relptr_access(base, btp->u.internal_key[i].child);
+ relptr_store(base, child->hdr.parent, btp);
+ }
+}
+
/*
* Debugging dump of btree data.
*/
static void
-FreePageManagerDumpBtree(FreePageManager *fpm, FreePageBtree *btp, int level,
- StringInfo buf)
+FreePageManagerDumpBtree(FreePageManager *fpm, FreePageBtree *btp,
+ FreePageBtree *parent, int level, StringInfo buf)
{
char *base = fpm_segment_base(fpm);
Size pageno = fpm_pointer_to_page(base, btp);
Size index;
+ FreePageBtree *check_parent;
check_stack_depth();
- appendStringInfo(buf, " %zu@%d %c:", pageno, level,
+ check_parent = relptr_access(base, btp->hdr.parent);
+ appendStringInfo(buf, " %zu@%d %c", pageno, level,
btp->hdr.magic == FREE_PAGE_INTERNAL_MAGIC ? 'i' : 'l');
+ if (parent != check_parent)
+ appendStringInfo(buf, " [actual parent %zu, expected %zu]",
+ fpm_pointer_to_page(base, check_parent),
+ fpm_pointer_to_page(base, parent));
+ appendStringInfoChar(buf, ':');
for (index = 0; index < btp->hdr.nused; ++index)
{
if (btp->hdr.magic == FREE_PAGE_INTERNAL_MAGIC)
FreePageBtree *child;
child = relptr_access(base, btp->u.internal_key[index].child);
- FreePageManagerDumpBtree(fpm, child, level + 1, buf);
+ FreePageManagerDumpBtree(fpm, child, btp, level + 1, buf);
}
}
}
return true;
}
-/*
- * Remove a FreePageSpanLeader from the linked-list that contains it, either
- * because we're changing the size of the span, or because we're allocating it.
- */
-static void
-FreePagePopSpanLeader(FreePageManager *fpm, Size pageno)
-{
- char *base = fpm_segment_base(fpm);
- FreePageSpanLeader *span;
- FreePageSpanLeader *next;
- FreePageSpanLeader *prev;
-
- span = (FreePageSpanLeader *) fpm_page_to_pointer(base, pageno);
-
- next = relptr_access(base, span->next);
- prev = relptr_access(base, span->prev);
- if (next != NULL)
- relptr_copy(next->prev, span->prev);
- if (prev != NULL)
- relptr_copy(prev->next, span->next);
- else
- {
- Size f = Min(span->npages, FPM_NUM_FREELISTS) - 1;
-
- Assert(fpm->freelist[f].relptr_off == pageno * FPM_PAGE_SIZE);
- relptr_copy(fpm->freelist[f], span->next);
- }
-}
-
-/*
- * Initialize a new FreePageSpanLeader and put it on the appropriate free list.
- */
-static void
-FreePagePushSpanLeader(FreePageManager *fpm, Size first_page, Size npages)
-{
- char *base = fpm_segment_base(fpm);
- Size f = Min(npages, FPM_NUM_FREELISTS) - 1;
- FreePageSpanLeader *head = relptr_access(base, fpm->freelist[f]);
- FreePageSpanLeader *span;
-
- span = (FreePageSpanLeader *) fpm_page_to_pointer(base, first_page);
- span->magic = FREE_PAGE_SPAN_LEADER_MAGIC;
- span->npages = npages;
- relptr_store(base, span->next, head);
- relptr_store(base, span->prev, (FreePageSpanLeader *) NULL);
- if (head != NULL)
- relptr_store(base, head->prev, span);
- relptr_store(base, fpm->freelist[f], span);
-}
-
/*
* Put a range of pages into the btree and freelists, consolidating it with
* existing free spans just before and/or after it. If 'soft' is true,
index = FreePageBtreeSearchInternal(insert_into, key);
FreePageBtreeInsertInternal(base, insert_into, index,
key, child);
+ relptr_store(base, child->hdr.parent, insert_into);
if (index == 0 && insert_into == split_target)
FreePageBtreeAdjustAncestorKeys(fpm, split_target);
}
index = FreePageBtreeSearchInternal(parent, key);
FreePageBtreeInsertInternal(base, parent, index,
key, newsibling);
+ relptr_store(base, newsibling->hdr.parent, parent);
if (index == 0)
FreePageBtreeAdjustAncestorKeys(fpm, parent);
break;
* free list, and we're done.
*/
FreePagePushSpanLeader(fpm, first_page, npages);
+
return true;
}
}
return true;
}
+
+/*
+ * Remove a FreePageSpanLeader from the linked-list that contains it, either
+ * because we're changing the size of the span, or because we're allocating it.
+ */
+static void
+FreePagePopSpanLeader(FreePageManager *fpm, Size pageno)
+{
+ char *base = fpm_segment_base(fpm);
+ FreePageSpanLeader *span;
+ FreePageSpanLeader *next;
+ FreePageSpanLeader *prev;
+
+ span = (FreePageSpanLeader *) fpm_page_to_pointer(base, pageno);
+
+ next = relptr_access(base, span->next);
+ prev = relptr_access(base, span->prev);
+ if (next != NULL)
+ relptr_copy(next->prev, span->prev);
+ if (prev != NULL)
+ relptr_copy(prev->next, span->next);
+ else
+ {
+ Size f = Min(span->npages, FPM_NUM_FREELISTS) - 1;
+
+ Assert(fpm->freelist[f].relptr_off == pageno * FPM_PAGE_SIZE);
+ relptr_copy(fpm->freelist[f], span->next);
+ }
+}
+
+/*
+ * Initialize a new FreePageSpanLeader and put it on the appropriate free list.
+ */
+static void
+FreePagePushSpanLeader(FreePageManager *fpm, Size first_page, Size npages)
+{
+ char *base = fpm_segment_base(fpm);
+ Size f = Min(npages, FPM_NUM_FREELISTS) - 1;
+ FreePageSpanLeader *head = relptr_access(base, fpm->freelist[f]);
+ FreePageSpanLeader *span;
+
+ span = (FreePageSpanLeader *) fpm_page_to_pointer(base, first_page);
+ span->magic = FREE_PAGE_SPAN_LEADER_MAGIC;
+ span->npages = npages;
+ relptr_store(base, span->next, head);
+ relptr_store(base, span->prev, (FreePageSpanLeader *) NULL);
+ if (head != NULL)
+ relptr_store(base, head->prev, span);
+ relptr_store(base, fpm->freelist[f], span);
+}
projects / users / rhaas / postgres.git / commitdiff