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/*------------------------------------------------------------------------- * * nbtree.h * header file for postgres btree access method implementation. * * * Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * src/include/access/nbtree.h * *------------------------------------------------------------------------- */ #ifndef NBTREE_H #define NBTREE_H #include "access/genam.h" #include "access/itup.h" #include "access/sdir.h" #include "access/xlog.h" #include "access/xlogutils.h" #include "catalog/pg_index.h" /* There's room for a 16-bit vacuum cycle ID in BTPageOpaqueData */ typedef uint16 BTCycleId; /* * BTPageOpaqueData -- At the end of every page, we store a pointer * to both siblings in the tree. This is used to do forward/backward * index scans. The next-page link is also critical for recovery when * a search has navigated to the wrong page due to concurrent page splits * or deletions; see src/backend/access/nbtree/README for more info. * * In addition, we store the page's btree level (counting upwards from * zero at a leaf page) as well as some flag bits indicating the page type * and status. If the page is deleted, we replace the level with the * next-transaction-ID value indicating when it is safe to reclaim the page. * * We also store a "vacuum cycle ID". When a page is split while VACUUM is * processing the index, a nonzero value associated with the VACUUM run is * stored into both halves of the split page. (If VACUUM is not running, * both pages receive zero cycleids.) This allows VACUUM to detect whether * a page was split since it started, with a small probability of false match * if the page was last split some exact multiple of MAX_BT_CYCLE_ID VACUUMs * ago. Also, during a split, the BTP_SPLIT_END flag is cleared in the left * (original) page, and set in the right page, but only if the next page * to its right has a different cycleid. * * NOTE: the BTP_LEAF flag bit is redundant since level==0 could be tested * instead. */ typedef struct BTPageOpaqueData { BlockNumber btpo_prev; /* left sibling, or P_NONE if leftmost */ BlockNumber btpo_next; /* right sibling, or P_NONE if rightmost */ union { uint32 level; /* tree level --- zero for leaf pages */ TransactionId xact; /* next transaction ID, if deleted */ } btpo; uint16 btpo_flags; /* flag bits, see below */ BTCycleId btpo_cycleid; /* vacuum cycle ID of latest split */ } BTPageOpaqueData; typedef BTPageOpaqueData *BTPageOpaque; /* Bits defined in btpo_flags */ #define BTP_LEAF (1 << 0) /* leaf page, i.e. not internal page */ #define BTP_ROOT (1 << 1) /* root page (has no parent) */ #define BTP_DELETED (1 << 2) /* page has been deleted from tree */ #define BTP_META (1 << 3) /* meta-page */ #define BTP_HALF_DEAD (1 << 4) /* empty, but still in tree */ #define BTP_SPLIT_END (1 << 5) /* rightmost page of split group */ #define BTP_HAS_GARBAGE (1 << 6) /* page has LP_DEAD tuples */ /* * The max allowed value of a cycle ID is a bit less than 64K. This is * for convenience of pg_filedump and similar utilities: we want to use * the last 2 bytes of special space as an index type indicator, and * restricting cycle ID lets btree use that space for vacuum cycle IDs * while still allowing index type to be identified. */ #define MAX_BT_CYCLE_ID 0xFF7F /* * The Meta page is always the first page in the btree index. * Its primary purpose is to point to the location of the btree root page. * We also point to the "fast" root, which is the current effective root; * see README for discussion. */ typedef struct BTMetaPageData { uint32 btm_magic; /* should contain BTREE_MAGIC */ uint32 btm_version; /* should contain BTREE_VERSION */ BlockNumber btm_root; /* current root location */ uint32 btm_level; /* tree level of the root page */ BlockNumber btm_fastroot; /* current "fast" root location */ uint32 btm_fastlevel; /* tree level of the "fast" root page */ } BTMetaPageData; #define BTPageGetMeta(p) \ ((BTMetaPageData *) PageGetContents(p)) #define BTREE_METAPAGE 0 /* first page is meta */ #define BTREE_MAGIC 0x053162 /* magic number of btree pages */ #define BTREE_VERSION 2 /* current version number */ /* * Maximum size of a btree index entry, including its tuple header. * * We actually need to be able to fit three items on every page, * so restrict any one item to 1/3 the per-page available space. */ #define BTMaxItemSize(page) \ MAXALIGN_DOWN((PageGetPageSize(page) - \ MAXALIGN(SizeOfPageHeaderData + 3*sizeof(ItemIdData)) - \ MAXALIGN(sizeof(BTPageOpaqueData))) / 3) /* * The leaf-page fillfactor defaults to 90% but is user-adjustable. * For pages above the leaf level, we use a fixed 70% fillfactor. * The fillfactor is applied during index build and when splitting * a rightmost page; when splitting non-rightmost pages we try to * divide the data equally. */ #define BTREE_MIN_FILLFACTOR 10 #define BTREE_DEFAULT_FILLFACTOR 90 #define BTREE_NONLEAF_FILLFACTOR 70 /* * Test whether two btree entries are "the same". * * Old comments: * In addition, we must guarantee that all tuples in the index are unique, * in order to satisfy some assumptions in Lehman and Yao. The way that we * do this is by generating a new OID for every insertion that we do in the * tree. This adds eight bytes to the size of btree index tuples. Note * that we do not use the OID as part of a composite key; the OID only * serves as a unique identifier for a given index tuple (logical position * within a page). * * New comments: * actually, we must guarantee that all tuples in A LEVEL * are unique, not in ALL INDEX. So, we can use the t_tid * as unique identifier for a given index tuple (logical position * within a level). - vadim 04/09/97 */ #define BTTidSame(i1, i2) \ ( (i1).ip_blkid.bi_hi == (i2).ip_blkid.bi_hi && \ (i1).ip_blkid.bi_lo == (i2).ip_blkid.bi_lo && \ (i1).ip_posid == (i2).ip_posid ) #define BTEntrySame(i1, i2) \ BTTidSame((i1)->t_tid, (i2)->t_tid) /* * In general, the btree code tries to localize its knowledge about * page layout to a couple of routines. However, we need a special * value to indicate "no page number" in those places where we expect * page numbers. We can use zero for this because we never need to * make a pointer to the metadata page. */ #define P_NONE 0 /* * Macros to test whether a page is leftmost or rightmost on its tree level, * as well as other state info kept in the opaque data. */ #define P_LEFTMOST(opaque) ((opaque)->btpo_prev == P_NONE) #define P_RIGHTMOST(opaque) ((opaque)->btpo_next == P_NONE) #define P_ISLEAF(opaque) ((opaque)->btpo_flags & BTP_LEAF) #define P_ISROOT(opaque) ((opaque)->btpo_flags & BTP_ROOT) #define P_ISDELETED(opaque) ((opaque)->btpo_flags & BTP_DELETED) #define P_ISHALFDEAD(opaque) ((opaque)->btpo_flags & BTP_HALF_DEAD) #define P_IGNORE(opaque) ((opaque)->btpo_flags & (BTP_DELETED|BTP_HALF_DEAD)) #define P_HAS_GARBAGE(opaque) ((opaque)->btpo_flags & BTP_HAS_GARBAGE) /* * Lehman and Yao's algorithm requires a ``high key'' on every non-rightmost * page. The high key is not a data key, but gives info about what range of * keys is supposed to be on this page. The high key on a page is required * to be greater than or equal to any data key that appears on the page. * If we find ourselves trying to insert a key > high key, we know we need * to move right (this should only happen if the page was split since we * examined the parent page). * * Our insertion algorithm guarantees that we can use the initial least key * on our right sibling as the high key. Once a page is created, its high * key changes only if the page is split. * * On a non-rightmost page, the high key lives in item 1 and data items * start in item 2. Rightmost pages have no high key, so we store data * items beginning in item 1. */ #define P_HIKEY ((OffsetNumber) 1) #define P_FIRSTKEY ((OffsetNumber) 2) #define P_FIRSTDATAKEY(opaque) (P_RIGHTMOST(opaque) ? P_HIKEY : P_FIRSTKEY) /* * XLOG records for btree operations * * XLOG allows to store some information in high 4 bits of log * record xl_info field */ #define XLOG_BTREE_INSERT_LEAF 0x00 /* add index tuple without split */ #define XLOG_BTREE_INSERT_UPPER 0x10 /* same, on a non-leaf page */ #define XLOG_BTREE_INSERT_META 0x20 /* same, plus update metapage */ #define XLOG_BTREE_SPLIT_L 0x30 /* add index tuple with split */ #define XLOG_BTREE_SPLIT_R 0x40 /* as above, new item on right */ #define XLOG_BTREE_SPLIT_L_ROOT 0x50 /* add tuple with split of root */ #define XLOG_BTREE_SPLIT_R_ROOT 0x60 /* as above, new item on right */ #define XLOG_BTREE_DELETE 0x70 /* delete leaf index tuples for a page */ #define XLOG_BTREE_DELETE_PAGE 0x80 /* delete an entire page */ #define XLOG_BTREE_DELETE_PAGE_META 0x90 /* same, and update metapage */ #define XLOG_BTREE_NEWROOT 0xA0 /* new root page */ #define XLOG_BTREE_DELETE_PAGE_HALF 0xB0 /* page deletion that makes * parent half-dead */ #define XLOG_BTREE_VACUUM 0xC0 /* delete entries on a page during * vacuum */ #define XLOG_BTREE_REUSE_PAGE 0xD0 /* old page is about to be reused from * FSM */ /* * All that we need to find changed index tuple */ typedef struct xl_btreetid { RelFileNode node; ItemPointerData tid; /* changed tuple id */ } xl_btreetid; /* * All that we need to regenerate the meta-data page */ typedef struct xl_btree_metadata { BlockNumber root; uint32 level; BlockNumber fastroot; uint32 fastlevel; } xl_btree_metadata; /* * This is what we need to know about simple (without split) insert. * * This data record is used for INSERT_LEAF, INSERT_UPPER, INSERT_META. * Note that INSERT_META implies it's not a leaf page. */ typedef struct xl_btree_insert { xl_btreetid target; /* inserted tuple id */ /* BlockNumber downlink field FOLLOWS IF NOT XLOG_BTREE_INSERT_LEAF */ /* xl_btree_metadata FOLLOWS IF XLOG_BTREE_INSERT_META */ /* INDEX TUPLE FOLLOWS AT END OF STRUCT */ } xl_btree_insert; #define SizeOfBtreeInsert (offsetof(xl_btreetid, tid) + SizeOfIptrData) /* * On insert with split, we save all the items going into the right sibling * so that we can restore it completely from the log record. This way takes * less xlog space than the normal approach, because if we did it standardly, * XLogInsert would almost always think the right page is new and store its * whole page image. The left page, however, is handled in the normal * incremental-update fashion. * * Note: the four XLOG_BTREE_SPLIT xl_info codes all use this data record. * The _L and _R variants indicate whether the inserted tuple went into the * left or right split page (and thus, whether newitemoff and the new item * are stored or not). The _ROOT variants indicate that we are splitting * the root page, and thus that a newroot record rather than an insert or * split record should follow. Note that a split record never carries a * metapage update --- we'll do that in the parent-level update. */ typedef struct xl_btree_split { RelFileNode node; BlockNumber leftsib; /* orig page / new left page */ BlockNumber rightsib; /* new right page */ BlockNumber rnext; /* next block (orig page's rightlink) */ uint32 level; /* tree level of page being split */ OffsetNumber firstright; /* first item moved to right page */ /* * If level > 0, BlockIdData downlink follows. (We use BlockIdData rather * than BlockNumber for alignment reasons: SizeOfBtreeSplit is only 16-bit * aligned.) * * If level > 0, an IndexTuple representing the HIKEY of the left page * follows. We don't need this on leaf pages, because it's the same as * the leftmost key in the new right page. Also, it's suppressed if * XLogInsert chooses to store the left page's whole page image. * * In the _L variants, next are OffsetNumber newitemoff and the new item. * (In the _R variants, the new item is one of the right page's tuples.) * The new item, but not newitemoff, is suppressed if XLogInsert chooses * to store the left page's whole page image. * * Last are the right page's tuples in the form used by _bt_restore_page. */ } xl_btree_split; #define SizeOfBtreeSplit (offsetof(xl_btree_split, firstright) + sizeof(OffsetNumber)) /* * This is what we need to know about delete of individual leaf index tuples. * The WAL record can represent deletion of any number of index tuples on a * single index page when *not* executed by VACUUM. */ typedef struct xl_btree_delete { RelFileNode node; /* RelFileNode of the index */ BlockNumber block; RelFileNode hnode; /* RelFileNode of the heap the index currently * points at */ int nitems; /* TARGET OFFSET NUMBERS FOLLOW AT THE END */ } xl_btree_delete; #define SizeOfBtreeDelete (offsetof(xl_btree_delete, nitems) + sizeof(int)) /* * This is what we need to know about page reuse within btree. */ typedef struct xl_btree_reuse_page { RelFileNode node; BlockNumber block; TransactionId latestRemovedXid; } xl_btree_reuse_page; #define SizeOfBtreeReusePage (sizeof(xl_btree_reuse_page)) /* * This is what we need to know about vacuum of individual leaf index tuples. * The WAL record can represent deletion of any number of index tuples on a * single index page when executed by VACUUM. * * The correctness requirement for applying these changes during recovery is * that we must do one of these two things for every block in the index: * * lock the block for cleanup and apply any required changes * * EnsureBlockUnpinned() * The purpose of this is to ensure that no index scans started before we * finish scanning the index are still running by the time we begin to remove * heap tuples. * * Any changes to any one block are registered on just one WAL record. All * blocks that we need to run EnsureBlockUnpinned() are listed as a block range * starting from the last block vacuumed through until this one. Individual * block numbers aren't given. * * Note that the *last* WAL record in any vacuum of an index is allowed to * have a zero length array of offsets. Earlier records must have at least one. */ typedef struct xl_btree_vacuum { RelFileNode node; BlockNumber block; BlockNumber lastBlockVacuumed; /* TARGET OFFSET NUMBERS FOLLOW */ } xl_btree_vacuum; #define SizeOfBtreeVacuum (offsetof(xl_btree_vacuum, lastBlockVacuumed) + sizeof(BlockNumber)) /* * This is what we need to know about deletion of a btree page. The target * identifies the tuple removed from the parent page (note that we remove * this tuple's downlink and the *following* tuple's key). Note we do not * store any content for the deleted page --- it is just rewritten as empty * during recovery, apart from resetting the btpo.xact. */ typedef struct xl_btree_delete_page { xl_btreetid target; /* deleted tuple id in parent page */ BlockNumber deadblk; /* child block being deleted */ BlockNumber leftblk; /* child block's left sibling, if any */ BlockNumber rightblk; /* child block's right sibling */ TransactionId btpo_xact; /* value of btpo.xact for use in recovery */ /* xl_btree_metadata FOLLOWS IF XLOG_BTREE_DELETE_PAGE_META */ } xl_btree_delete_page; #define SizeOfBtreeDeletePage (offsetof(xl_btree_delete_page, btpo_xact) + sizeof(TransactionId)) /* * New root log record. There are zero tuples if this is to establish an * empty root, or two if it is the result of splitting an old root. * * Note that although this implies rewriting the metadata page, we don't need * an xl_btree_metadata record --- the rootblk and level are sufficient. */ typedef struct xl_btree_newroot { RelFileNode node; BlockNumber rootblk; /* location of new root */ uint32 level; /* its tree level */ /* 0 or 2 INDEX TUPLES FOLLOW AT END OF STRUCT */ } xl_btree_newroot; #define SizeOfBtreeNewroot (offsetof(xl_btree_newroot, level) + sizeof(uint32)) /* * Operator strategy numbers for B-tree have been moved to access/skey.h, * because many places need to use them in ScanKeyInit() calls. * * The strategy numbers are chosen so that we can commute them by * subtraction, thus: */ #define BTCommuteStrategyNumber(strat) (BTMaxStrategyNumber + 1 - (strat)) /* * When a new operator class is declared, we require that the user * supply us with an amproc procedure (BTORDER_PROC) for determining * whether, for two keys a and b, a < b, a = b, or a > b. This routine * must return < 0, 0, > 0, respectively, in these three cases. (It must * not return INT_MIN, since we may negate the result before using it.) * * To facilitate accelerated sorting, an operator class may choose to * offer a second procedure (BTSORTSUPPORT_PROC). For full details, see * src/include/utils/sortsupport.h. */ #define BTORDER_PROC 1 #define BTSORTSUPPORT_PROC 2 /* * We need to be able to tell the difference between read and write * requests for pages, in order to do locking correctly. */ #define BT_READ BUFFER_LOCK_SHARE #define BT_WRITE BUFFER_LOCK_EXCLUSIVE /* * BTStackData -- As we descend a tree, we push the (location, downlink) * pairs from internal pages onto a private stack. If we split a * leaf, we use this stack to walk back up the tree and insert data * into parent pages (and possibly to split them, too). Lehman and * Yao's update algorithm guarantees that under no circumstances can * our private stack give us an irredeemably bad picture up the tree. * Again, see the paper for details. */ typedef struct BTStackData { BlockNumber bts_blkno; OffsetNumber bts_offset; IndexTupleData bts_btentry; struct BTStackData *bts_parent; } BTStackData; typedef BTStackData *BTStack; /* * BTScanOpaqueData is the btree-private state needed for an indexscan. * This consists of preprocessed scan keys (see _bt_preprocess_keys() for * details of the preprocessing), information about the current location * of the scan, and information about the marked location, if any. (We use * BTScanPosData to represent the data needed for each of current and marked * locations.) In addition we can remember some known-killed index entries * that must be marked before we can move off the current page. * * Index scans work a page at a time: we pin and read-lock the page, identify * all the matching items on the page and save them in BTScanPosData, then * release the read-lock while returning the items to the caller for * processing. This approach minimizes lock/unlock traffic. Note that we * keep the pin on the index page until the caller is done with all the items * (this is needed for VACUUM synchronization, see nbtree/README). When we * are ready to step to the next page, if the caller has told us any of the * items were killed, we re-lock the page to mark them killed, then unlock. * Finally we drop the pin and step to the next page in the appropriate * direction. * * If we are doing an index-only scan, we save the entire IndexTuple for each * matched item, otherwise only its heap TID and offset. The IndexTuples go * into a separate workspace array; each BTScanPosItem stores its tuple's * offset within that array. */ typedef struct BTScanPosItem /* what we remember about each match */ { ItemPointerData heapTid; /* TID of referenced heap item */ OffsetNumber indexOffset; /* index item's location within page */ LocationIndex tupleOffset; /* IndexTuple's offset in workspace, if any */ } BTScanPosItem; typedef struct BTScanPosData { Buffer buf; /* if valid, the buffer is pinned */ BlockNumber nextPage; /* page's right link when we scanned it */ /* * moreLeft and moreRight track whether we think there may be matching * index entries to the left and right of the current page, respectively. * We can clear the appropriate one of these flags when _bt_checkkeys() * returns continuescan = false. */ bool moreLeft; bool moreRight; /* * If we are doing an index-only scan, nextTupleOffset is the first free * location in the associated tuple storage workspace. */ int nextTupleOffset; /* * The items array is always ordered in index order (ie, increasing * indexoffset). When scanning backwards it is convenient to fill the * array back-to-front, so we start at the last slot and fill downwards. * Hence we need both a first-valid-entry and a last-valid-entry counter. * itemIndex is a cursor showing which entry was last returned to caller. */ int firstItem; /* first valid index in items[] */ int lastItem; /* last valid index in items[] */ int itemIndex; /* current index in items[] */ BTScanPosItem items[MaxIndexTuplesPerPage]; /* MUST BE LAST */ } BTScanPosData; typedef BTScanPosData *BTScanPos; #define BTScanPosIsValid(scanpos) BufferIsValid((scanpos).buf) /* We need one of these for each equality-type SK_SEARCHARRAY scan key */ typedef struct BTArrayKeyInfo { int scan_key; /* index of associated key in arrayKeyData */ int cur_elem; /* index of current element in elem_values */ int mark_elem; /* index of marked element in elem_values */ int num_elems; /* number of elems in current array value */ Datum *elem_values; /* array of num_elems Datums */ } BTArrayKeyInfo; typedef struct BTScanOpaqueData { /* these fields are set by _bt_preprocess_keys(): */ bool qual_ok; /* false if qual can never be satisfied */ int numberOfKeys; /* number of preprocessed scan keys */ ScanKey keyData; /* array of preprocessed scan keys */ /* workspace for SK_SEARCHARRAY support */ ScanKey arrayKeyData; /* modified copy of scan->keyData */ int numArrayKeys; /* number of equality-type array keys (-1 if * there are any unsatisfiable array keys) */ BTArrayKeyInfo *arrayKeys; /* info about each equality-type array key */ MemoryContext arrayContext; /* scan-lifespan context for array data */ /* info about killed items if any (killedItems is NULL if never used) */ int *killedItems; /* currPos.items indexes of killed items */ int numKilled; /* number of currently stored items */ /* * If we are doing an index-only scan, these are the tuple storage * workspaces for the currPos and markPos respectively. Each is of size * BLCKSZ, so it can hold as much as a full page's worth of tuples. */ char *currTuples; /* tuple storage for currPos */ char *markTuples; /* tuple storage for markPos */ /* * If the marked position is on the same page as current position, we * don't use markPos, but just keep the marked itemIndex in markItemIndex * (all the rest of currPos is valid for the mark position). Hence, to * determine if there is a mark, first look at markItemIndex, then at * markPos. */ int markItemIndex; /* itemIndex, or -1 if not valid */ /* keep these last in struct for efficiency */ BTScanPosData currPos; /* current position data */ BTScanPosData markPos; /* marked position, if any */ } BTScanOpaqueData; typedef BTScanOpaqueData *BTScanOpaque; /* * We use some private sk_flags bits in preprocessed scan keys. We're allowed * to use bits 16-31 (see skey.h). The uppermost bits are copied from the * index's indoption[] array entry for the index attribute. */ #define SK_BT_REQFWD 0x00010000 /* required to continue forward scan */ #define SK_BT_REQBKWD 0x00020000 /* required to continue backward scan */ #define SK_BT_INDOPTION_SHIFT 24 /* must clear the above bits */ #define SK_BT_DESC (INDOPTION_DESC << SK_BT_INDOPTION_SHIFT) #define SK_BT_NULLS_FIRST (INDOPTION_NULLS_FIRST << SK_BT_INDOPTION_SHIFT) /* * prototypes for functions in nbtree.c (external entry points for btree) */ extern Datum btbuild(PG_FUNCTION_ARGS); extern Datum btbuildempty(PG_FUNCTION_ARGS); extern Datum btinsert(PG_FUNCTION_ARGS); extern Datum btbeginscan(PG_FUNCTION_ARGS); extern Datum btgettuple(PG_FUNCTION_ARGS); extern Datum btgetbitmap(PG_FUNCTION_ARGS); extern Datum btrescan(PG_FUNCTION_ARGS); extern Datum btendscan(PG_FUNCTION_ARGS); extern Datum btmarkpos(PG_FUNCTION_ARGS); extern Datum btrestrpos(PG_FUNCTION_ARGS); extern Datum btbulkdelete(PG_FUNCTION_ARGS); extern Datum btvacuumcleanup(PG_FUNCTION_ARGS); extern Datum btcanreturn(PG_FUNCTION_ARGS); extern Datum btoptions(PG_FUNCTION_ARGS); /* * prototypes for functions in nbtinsert.c */ extern bool _bt_doinsert(Relation rel, IndexTuple itup, IndexUniqueCheck checkUnique, Relation heapRel); extern Buffer _bt_getstackbuf(Relation rel, BTStack stack, int access); extern void _bt_insert_parent(Relation rel, Buffer buf, Buffer rbuf, BTStack stack, bool is_root, bool is_only); /* * prototypes for functions in nbtpage.c */ extern void _bt_initmetapage(Page page, BlockNumber rootbknum, uint32 level); extern Buffer _bt_getroot(Relation rel, int access); extern Buffer _bt_gettrueroot(Relation rel); extern void _bt_checkpage(Relation rel, Buffer buf); extern Buffer _bt_getbuf(Relation rel, BlockNumber blkno, int access); extern Buffer _bt_relandgetbuf(Relation rel, Buffer obuf, BlockNumber blkno, int access); extern void _bt_relbuf(Relation rel, Buffer buf); extern void _bt_pageinit(Page page, Size size); extern bool _bt_page_recyclable(Page page); extern void _bt_delitems_delete(Relation rel, Buffer buf, OffsetNumber *itemnos, int nitems, Relation heapRel); extern void _bt_delitems_vacuum(Relation rel, Buffer buf, OffsetNumber *itemnos, int nitems, BlockNumber lastBlockVacuumed); extern int _bt_pagedel(Relation rel, Buffer buf, BTStack stack); /* * prototypes for functions in nbtsearch.c */ extern BTStack _bt_search(Relation rel, int keysz, ScanKey scankey, bool nextkey, Buffer *bufP, int access); extern Buffer _bt_moveright(Relation rel, Buffer buf, int keysz, ScanKey scankey, bool nextkey, int access); extern OffsetNumber _bt_binsrch(Relation rel, Buffer buf, int keysz, ScanKey scankey, bool nextkey); extern int32 _bt_compare(Relation rel, int keysz, ScanKey scankey, Page page, OffsetNumber offnum); extern bool _bt_first(IndexScanDesc scan, ScanDirection dir); extern bool _bt_next(IndexScanDesc scan, ScanDirection dir); extern Buffer _bt_get_endpoint(Relation rel, uint32 level, bool rightmost); /* * prototypes for functions in nbtutils.c */ extern ScanKey _bt_mkscankey(Relation rel, IndexTuple itup); extern ScanKey _bt_mkscankey_nodata(Relation rel); extern void _bt_freeskey(ScanKey skey); extern void _bt_freestack(BTStack stack); extern void _bt_preprocess_array_keys(IndexScanDesc scan); extern void _bt_start_array_keys(IndexScanDesc scan, ScanDirection dir); extern bool _bt_advance_array_keys(IndexScanDesc scan, ScanDirection dir); extern void _bt_mark_array_keys(IndexScanDesc scan); extern void _bt_restore_array_keys(IndexScanDesc scan); extern void _bt_preprocess_keys(IndexScanDesc scan); extern IndexTuple _bt_checkkeys(IndexScanDesc scan, Page page, OffsetNumber offnum, ScanDirection dir, bool *continuescan); extern void _bt_killitems(IndexScanDesc scan, bool haveLock); extern BTCycleId _bt_vacuum_cycleid(Relation rel); extern BTCycleId _bt_start_vacuum(Relation rel); extern void _bt_end_vacuum(Relation rel); extern void _bt_end_vacuum_callback(int code, Datum arg); extern Size BTreeShmemSize(void); extern void BTreeShmemInit(void); /* * prototypes for functions in nbtsort.c */ typedef struct BTSpool BTSpool; /* opaque type known only within nbtsort.c */ extern BTSpool *_bt_spoolinit(Relation index, bool isunique, bool isdead); extern void _bt_spooldestroy(BTSpool *btspool); extern void _bt_spool(IndexTuple itup, BTSpool *btspool); extern void _bt_leafbuild(BTSpool *btspool, BTSpool *spool2); /* * prototypes for functions in nbtxlog.c */ extern void btree_redo(XLogRecPtr lsn, XLogRecord *record); extern void btree_desc(StringInfo buf, uint8 xl_info, char *rec); extern void btree_xlog_startup(void); extern void btree_xlog_cleanup(void); extern bool btree_safe_restartpoint(void); #endif /* NBTREE_H */