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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 12:15:05 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 12:15:05 +0000
commit46651ce6fe013220ed397add242004d764fc0153 (patch)
tree6e5299f990f88e60174a1d3ae6e48eedd2688b2b /src/include/access/ginblock.h
parentInitial commit. (diff)
downloadpostgresql-14-46651ce6fe013220ed397add242004d764fc0153.tar.xz
postgresql-14-46651ce6fe013220ed397add242004d764fc0153.zip
Adding upstream version 14.5.upstream/14.5upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+/*--------------------------------------------------------------------------
+ * ginblock.h
+ * details of structures stored in GIN index blocks
+ *
+ * Copyright (c) 2006-2021, PostgreSQL Global Development Group
+ *
+ * src/include/access/ginblock.h
+ *--------------------------------------------------------------------------
+ */
+#ifndef GINBLOCK_H
+#define GINBLOCK_H
+
+#include "access/transam.h"
+#include "storage/block.h"
+#include "storage/bufpage.h"
+#include "storage/itemptr.h"
+#include "storage/off.h"
+
+/*
+ * Page opaque data in an inverted index page.
+ *
+ * Note: GIN does not include a page ID word as do the other index types.
+ * This is OK because the opaque data is only 8 bytes and so can be reliably
+ * distinguished by size. Revisit this if the size ever increases.
+ * Further note: as of 9.2, SP-GiST also uses 8-byte special space, as does
+ * BRIN as of 9.5. This is still OK, as long as GIN isn't using all of the
+ * high-order bits in its flags word, because that way the flags word cannot
+ * match the page IDs used by SP-GiST and BRIN.
+ */
+typedef struct GinPageOpaqueData
+{
+ BlockNumber rightlink; /* next page if any */
+ OffsetNumber maxoff; /* number of PostingItems on GIN_DATA &
+ * ~GIN_LEAF page. On GIN_LIST page, number of
+ * heap tuples. */
+ uint16 flags; /* see bit definitions below */
+} GinPageOpaqueData;
+
+typedef GinPageOpaqueData *GinPageOpaque;
+
+#define GIN_DATA (1 << 0)
+#define GIN_LEAF (1 << 1)
+#define GIN_DELETED (1 << 2)
+#define GIN_META (1 << 3)
+#define GIN_LIST (1 << 4)
+#define GIN_LIST_FULLROW (1 << 5) /* makes sense only on GIN_LIST page */
+#define GIN_INCOMPLETE_SPLIT (1 << 6) /* page was split, but parent not
+ * updated */
+#define GIN_COMPRESSED (1 << 7)
+
+/* Page numbers of fixed-location pages */
+#define GIN_METAPAGE_BLKNO (0)
+#define GIN_ROOT_BLKNO (1)
+
+typedef struct GinMetaPageData
+{
+ /*
+ * Pointers to head and tail of pending list, which consists of GIN_LIST
+ * pages. These store fast-inserted entries that haven't yet been moved
+ * into the regular GIN structure.
+ */
+ BlockNumber head;
+ BlockNumber tail;
+
+ /*
+ * Free space in bytes in the pending list's tail page.
+ */
+ uint32 tailFreeSize;
+
+ /*
+ * We store both number of pages and number of heap tuples that are in the
+ * pending list.
+ */
+ BlockNumber nPendingPages;
+ int64 nPendingHeapTuples;
+
+ /*
+ * Statistics for planner use (accurate as of last VACUUM)
+ */
+ BlockNumber nTotalPages;
+ BlockNumber nEntryPages;
+ BlockNumber nDataPages;
+ int64 nEntries;
+
+ /*
+ * GIN version number (ideally this should have been at the front, but too
+ * late now. Don't move it!)
+ *
+ * Currently 2 (for indexes initialized in 9.4 or later)
+ *
+ * Version 1 (indexes initialized in version 9.1, 9.2 or 9.3), is
+ * compatible, but may contain uncompressed posting tree (leaf) pages and
+ * posting lists. They will be converted to compressed format when
+ * modified.
+ *
+ * Version 0 (indexes initialized in 9.0 or before) is compatible but may
+ * be missing null entries, including both null keys and placeholders.
+ * Reject full-index-scan attempts on such indexes.
+ */
+ int32 ginVersion;
+} GinMetaPageData;
+
+#define GIN_CURRENT_VERSION 2
+
+#define GinPageGetMeta(p) \
+ ((GinMetaPageData *) PageGetContents(p))
+
+/*
+ * Macros for accessing a GIN index page's opaque data
+ */
+#define GinPageGetOpaque(page) ( (GinPageOpaque) PageGetSpecialPointer(page) )
+
+#define GinPageIsLeaf(page) ( (GinPageGetOpaque(page)->flags & GIN_LEAF) != 0 )
+#define GinPageSetLeaf(page) ( GinPageGetOpaque(page)->flags |= GIN_LEAF )
+#define GinPageSetNonLeaf(page) ( GinPageGetOpaque(page)->flags &= ~GIN_LEAF )
+#define GinPageIsData(page) ( (GinPageGetOpaque(page)->flags & GIN_DATA) != 0 )
+#define GinPageSetData(page) ( GinPageGetOpaque(page)->flags |= GIN_DATA )
+#define GinPageIsList(page) ( (GinPageGetOpaque(page)->flags & GIN_LIST) != 0 )
+#define GinPageSetList(page) ( GinPageGetOpaque(page)->flags |= GIN_LIST )
+#define GinPageHasFullRow(page) ( (GinPageGetOpaque(page)->flags & GIN_LIST_FULLROW) != 0 )
+#define GinPageSetFullRow(page) ( GinPageGetOpaque(page)->flags |= GIN_LIST_FULLROW )
+#define GinPageIsCompressed(page) ( (GinPageGetOpaque(page)->flags & GIN_COMPRESSED) != 0 )
+#define GinPageSetCompressed(page) ( GinPageGetOpaque(page)->flags |= GIN_COMPRESSED )
+
+#define GinPageIsDeleted(page) ( (GinPageGetOpaque(page)->flags & GIN_DELETED) != 0 )
+#define GinPageSetDeleted(page) ( GinPageGetOpaque(page)->flags |= GIN_DELETED)
+#define GinPageSetNonDeleted(page) ( GinPageGetOpaque(page)->flags &= ~GIN_DELETED)
+#define GinPageIsIncompleteSplit(page) ( (GinPageGetOpaque(page)->flags & GIN_INCOMPLETE_SPLIT) != 0 )
+
+#define GinPageRightMost(page) ( GinPageGetOpaque(page)->rightlink == InvalidBlockNumber)
+
+/*
+ * We should reclaim deleted page only once every transaction started before
+ * its deletion is over.
+ */
+#define GinPageGetDeleteXid(page) ( ((PageHeader) (page))->pd_prune_xid )
+#define GinPageSetDeleteXid(page, xid) ( ((PageHeader) (page))->pd_prune_xid = xid)
+extern bool GinPageIsRecyclable(Page page);
+
+/*
+ * We use our own ItemPointerGet(BlockNumber|OffsetNumber)
+ * to avoid Asserts, since sometimes the ip_posid isn't "valid"
+ */
+#define GinItemPointerGetBlockNumber(pointer) \
+ (ItemPointerGetBlockNumberNoCheck(pointer))
+
+#define GinItemPointerGetOffsetNumber(pointer) \
+ (ItemPointerGetOffsetNumberNoCheck(pointer))
+
+#define GinItemPointerSetBlockNumber(pointer, blkno) \
+ (ItemPointerSetBlockNumber((pointer), (blkno)))
+
+#define GinItemPointerSetOffsetNumber(pointer, offnum) \
+ (ItemPointerSetOffsetNumber((pointer), (offnum)))
+
+
+/*
+ * Special-case item pointer values needed by the GIN search logic.
+ * MIN: sorts less than any valid item pointer
+ * MAX: sorts greater than any valid item pointer
+ * LOSSY PAGE: indicates a whole heap page, sorts after normal item
+ * pointers for that page
+ * Note that these are all distinguishable from an "invalid" item pointer
+ * (which is InvalidBlockNumber/0) as well as from all normal item
+ * pointers (which have item numbers in the range 1..MaxHeapTuplesPerPage).
+ */
+#define ItemPointerSetMin(p) \
+ ItemPointerSet((p), (BlockNumber)0, (OffsetNumber)0)
+#define ItemPointerIsMin(p) \
+ (GinItemPointerGetOffsetNumber(p) == (OffsetNumber)0 && \
+ GinItemPointerGetBlockNumber(p) == (BlockNumber)0)
+#define ItemPointerSetMax(p) \
+ ItemPointerSet((p), InvalidBlockNumber, (OffsetNumber)0xffff)
+#define ItemPointerSetLossyPage(p, b) \
+ ItemPointerSet((p), (b), (OffsetNumber)0xffff)
+#define ItemPointerIsLossyPage(p) \
+ (GinItemPointerGetOffsetNumber(p) == (OffsetNumber)0xffff && \
+ GinItemPointerGetBlockNumber(p) != InvalidBlockNumber)
+
+/*
+ * Posting item in a non-leaf posting-tree page
+ */
+typedef struct
+{
+ /* We use BlockIdData not BlockNumber to avoid padding space wastage */
+ BlockIdData child_blkno;
+ ItemPointerData key;
+} PostingItem;
+
+#define PostingItemGetBlockNumber(pointer) \
+ BlockIdGetBlockNumber(&(pointer)->child_blkno)
+
+#define PostingItemSetBlockNumber(pointer, blockNumber) \
+ BlockIdSet(&((pointer)->child_blkno), (blockNumber))
+
+/*
+ * Category codes to distinguish placeholder nulls from ordinary NULL keys.
+ *
+ * The first two code values were chosen to be compatible with the usual usage
+ * of bool isNull flags. However, casting between bool and GinNullCategory is
+ * risky because of the possibility of different bit patterns and type sizes,
+ * so it is no longer done.
+ *
+ * GIN_CAT_EMPTY_QUERY is never stored in the index; and notice that it is
+ * chosen to sort before not after regular key values.
+ */
+typedef signed char GinNullCategory;
+
+#define GIN_CAT_NORM_KEY 0 /* normal, non-null key value */
+#define GIN_CAT_NULL_KEY 1 /* null key value */
+#define GIN_CAT_EMPTY_ITEM 2 /* placeholder for zero-key item */
+#define GIN_CAT_NULL_ITEM 3 /* placeholder for null item */
+#define GIN_CAT_EMPTY_QUERY (-1) /* placeholder for full-scan query */
+
+/*
+ * Access macros for null category byte in entry tuples
+ */
+#define GinCategoryOffset(itup,ginstate) \
+ (IndexInfoFindDataOffset((itup)->t_info) + \
+ ((ginstate)->oneCol ? 0 : sizeof(int16)))
+#define GinGetNullCategory(itup,ginstate) \
+ (*((GinNullCategory *) ((char*)(itup) + GinCategoryOffset(itup,ginstate))))
+#define GinSetNullCategory(itup,ginstate,c) \
+ (*((GinNullCategory *) ((char*)(itup) + GinCategoryOffset(itup,ginstate))) = (c))
+
+/*
+ * Access macros for leaf-page entry tuples (see discussion in README)
+ */
+#define GinGetNPosting(itup) GinItemPointerGetOffsetNumber(&(itup)->t_tid)
+#define GinSetNPosting(itup,n) ItemPointerSetOffsetNumber(&(itup)->t_tid,n)
+#define GIN_TREE_POSTING ((OffsetNumber)0xffff)
+#define GinIsPostingTree(itup) (GinGetNPosting(itup) == GIN_TREE_POSTING)
+#define GinSetPostingTree(itup, blkno) ( GinSetNPosting((itup),GIN_TREE_POSTING), ItemPointerSetBlockNumber(&(itup)->t_tid, blkno) )
+#define GinGetPostingTree(itup) GinItemPointerGetBlockNumber(&(itup)->t_tid)
+
+#define GIN_ITUP_COMPRESSED (1U << 31)
+#define GinGetPostingOffset(itup) (GinItemPointerGetBlockNumber(&(itup)->t_tid) & (~GIN_ITUP_COMPRESSED))
+#define GinSetPostingOffset(itup,n) ItemPointerSetBlockNumber(&(itup)->t_tid,(n)|GIN_ITUP_COMPRESSED)
+#define GinGetPosting(itup) ((Pointer) ((char*)(itup) + GinGetPostingOffset(itup)))
+#define GinItupIsCompressed(itup) ((GinItemPointerGetBlockNumber(&(itup)->t_tid) & GIN_ITUP_COMPRESSED) != 0)
+
+/*
+ * Maximum size of an item on entry tree page. Make sure that we fit at least
+ * three items on each page. (On regular B-tree indexes, we must fit at least
+ * three items: two data items and the "high key". In GIN entry tree, we don't
+ * currently store the high key explicitly, we just use the rightmost item on
+ * the page, so it would actually be enough to fit two items.)
+ */
+#define GinMaxItemSize \
+ Min(INDEX_SIZE_MASK, \
+ MAXALIGN_DOWN(((BLCKSZ - \
+ MAXALIGN(SizeOfPageHeaderData + 3 * sizeof(ItemIdData)) - \
+ MAXALIGN(sizeof(GinPageOpaqueData))) / 3)))
+
+/*
+ * Access macros for non-leaf entry tuples
+ */
+#define GinGetDownlink(itup) GinItemPointerGetBlockNumber(&(itup)->t_tid)
+#define GinSetDownlink(itup,blkno) ItemPointerSet(&(itup)->t_tid, blkno, InvalidOffsetNumber)
+
+
+/*
+ * Data (posting tree) pages
+ *
+ * Posting tree pages don't store regular tuples. Non-leaf pages contain
+ * PostingItems, which are pairs of ItemPointers and child block numbers.
+ * Leaf pages contain GinPostingLists and an uncompressed array of item
+ * pointers.
+ *
+ * In a leaf page, the compressed posting lists are stored after the regular
+ * page header, one after each other. Although we don't store regular tuples,
+ * pd_lower is used to indicate the end of the posting lists. After that, free
+ * space follows. This layout is compatible with the "standard" heap and
+ * index page layout described in bufpage.h, so that we can e.g set buffer_std
+ * when writing WAL records.
+ *
+ * In the special space is the GinPageOpaque struct.
+ */
+#define GinDataLeafPageGetPostingList(page) \
+ (GinPostingList *) ((PageGetContents(page) + MAXALIGN(sizeof(ItemPointerData))))
+#define GinDataLeafPageGetPostingListSize(page) \
+ (((PageHeader) page)->pd_lower - MAXALIGN(SizeOfPageHeaderData) - MAXALIGN(sizeof(ItemPointerData)))
+
+#define GinDataLeafPageIsEmpty(page) \
+ (GinPageIsCompressed(page) ? (GinDataLeafPageGetPostingListSize(page) == 0) : (GinPageGetOpaque(page)->maxoff < FirstOffsetNumber))
+
+#define GinDataLeafPageGetFreeSpace(page) PageGetExactFreeSpace(page)
+
+#define GinDataPageGetRightBound(page) ((ItemPointer) PageGetContents(page))
+/*
+ * Pointer to the data portion of a posting tree page. For internal pages,
+ * that's the beginning of the array of PostingItems. For compressed leaf
+ * pages, the first compressed posting list. For uncompressed (pre-9.4) leaf
+ * pages, it's the beginning of the ItemPointer array.
+ */
+#define GinDataPageGetData(page) \
+ (PageGetContents(page) + MAXALIGN(sizeof(ItemPointerData)))
+/* non-leaf pages contain PostingItems */
+#define GinDataPageGetPostingItem(page, i) \
+ ((PostingItem *) (GinDataPageGetData(page) + ((i)-1) * sizeof(PostingItem)))
+
+/*
+ * Note: there is no GinDataPageGetDataSize macro, because before version
+ * 9.4, we didn't set pd_lower on data pages. There can be pages in the index
+ * that were binary-upgraded from earlier versions and still have an invalid
+ * pd_lower, so we cannot trust it in general. Compressed posting tree leaf
+ * pages are new in 9.4, however, so we can trust them; see
+ * GinDataLeafPageGetPostingListSize.
+ */
+#define GinDataPageSetDataSize(page, size) \
+ { \
+ Assert(size <= GinDataPageMaxDataSize); \
+ ((PageHeader) page)->pd_lower = (size) + MAXALIGN(SizeOfPageHeaderData) + MAXALIGN(sizeof(ItemPointerData)); \
+ }
+
+#define GinNonLeafDataPageGetFreeSpace(page) \
+ (GinDataPageMaxDataSize - \
+ GinPageGetOpaque(page)->maxoff * sizeof(PostingItem))
+
+#define GinDataPageMaxDataSize \
+ (BLCKSZ - MAXALIGN(SizeOfPageHeaderData) \
+ - MAXALIGN(sizeof(ItemPointerData)) \
+ - MAXALIGN(sizeof(GinPageOpaqueData)))
+
+/*
+ * List pages
+ */
+#define GinListPageSize \
+ ( BLCKSZ - SizeOfPageHeaderData - MAXALIGN(sizeof(GinPageOpaqueData)) )
+
+/*
+ * A compressed posting list.
+ *
+ * Note: This requires 2-byte alignment.
+ */
+typedef struct
+{
+ ItemPointerData first; /* first item in this posting list (unpacked) */
+ uint16 nbytes; /* number of bytes that follow */
+ unsigned char bytes[FLEXIBLE_ARRAY_MEMBER]; /* varbyte encoded items */
+} GinPostingList;
+
+#define SizeOfGinPostingList(plist) (offsetof(GinPostingList, bytes) + SHORTALIGN((plist)->nbytes) )
+#define GinNextPostingListSegment(cur) ((GinPostingList *) (((char *) (cur)) + SizeOfGinPostingList((cur))))
+
+#endif /* GINBLOCK_H */