heapam.h

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/*-------------------------------------------------------------------------
 *
 * heapam.h
 *    POSTGRES heap access method definitions.
 *
 *
 * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/access/heapam.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef HEAPAM_H
#define HEAPAM_H

#include "access/relation.h"    /* for backward compatibility */
#include "access/relscan.h"
#include "access/sdir.h"
#include "access/skey.h"
#include "access/table.h"       /* for backward compatibility */
#include "access/tableam.h"
#include "nodes/lockoptions.h"
#include "nodes/primnodes.h"
#include "storage/bufpage.h"
#include "storage/dsm.h"
#include "storage/lockdefs.h"
#include "storage/shm_toc.h"
#include "utils/relcache.h"
#include "utils/snapshot.h"


/* "options" flag bits for heap_insert */
#define HEAP_INSERT_SKIP_WAL    TABLE_INSERT_SKIP_WAL
#define HEAP_INSERT_SKIP_FSM    TABLE_INSERT_SKIP_FSM
#define HEAP_INSERT_FROZEN      TABLE_INSERT_FROZEN
#define HEAP_INSERT_NO_LOGICAL  TABLE_INSERT_NO_LOGICAL
#define HEAP_INSERT_SPECULATIVE 0x0010

typedef struct BulkInsertStateData *BulkInsertState;
struct TupleTableSlot;

#define MaxLockTupleMode    LockTupleExclusive

/*
 * Descriptor for heap table scans.
 */
typedef struct HeapScanDescData
{
    TableScanDescData rs_base;  /* AM independent part of the descriptor */

    /* state set up at initscan time */
    BlockNumber rs_nblocks;     /* total number of blocks in rel */
    BlockNumber rs_startblock;  /* block # to start at */
    BlockNumber rs_numblocks;   /* max number of blocks to scan */
    /* rs_numblocks is usually InvalidBlockNumber, meaning "scan whole rel" */

    /* scan current state */
    bool        rs_inited;      /* false = scan not init'd yet */
    BlockNumber rs_cblock;      /* current block # in scan, if any */
    Buffer      rs_cbuf;        /* current buffer in scan, if any */
    /* NB: if rs_cbuf is not InvalidBuffer, we hold a pin on that buffer */

    /* rs_numblocks is usually InvalidBlockNumber, meaning "scan whole rel" */
    BufferAccessStrategy rs_strategy;   /* access strategy for reads */

    HeapTupleData rs_ctup;      /* current tuple in scan, if any */

    /* these fields only used in page-at-a-time mode and for bitmap scans */
    int         rs_cindex;      /* current tuple's index in vistuples */
    int         rs_ntuples;     /* number of visible tuples on page */
    OffsetNumber rs_vistuples[MaxHeapTuplesPerPage];    /* their offsets */
}           HeapScanDescData;
typedef struct HeapScanDescData *HeapScanDesc;

/*
 * Descriptor for fetches from heap via an index.
 */
typedef struct IndexFetchHeapData
{
    IndexFetchTableData xs_base;    /* AM independent part of the descriptor */

    Buffer      xs_cbuf;        /* current heap buffer in scan, if any */
    /* NB: if xs_cbuf is not InvalidBuffer, we hold a pin on that buffer */
} IndexFetchHeapData;

/* Result codes for HeapTupleSatisfiesVacuum */
typedef enum
{
    HEAPTUPLE_DEAD,             /* tuple is dead and deletable */
    HEAPTUPLE_LIVE,             /* tuple is live (committed, no deleter) */
    HEAPTUPLE_RECENTLY_DEAD,    /* tuple is dead, but not deletable yet */
    HEAPTUPLE_INSERT_IN_PROGRESS,   /* inserting xact is still in progress */
    HEAPTUPLE_DELETE_IN_PROGRESS    /* deleting xact is still in progress */
} HTSV_Result;

/* ----------------
 *      function prototypes for heap access method
 *
 * heap_create, heap_create_with_catalog, and heap_drop_with_catalog
 * are declared in catalog/heap.h
 * ----------------
 */


/*
 * HeapScanIsValid
 *      True iff the heap scan is valid.
 */
#define HeapScanIsValid(scan) PointerIsValid(scan)

extern TableScanDesc heap_beginscan(Relation relation, Snapshot snapshot,
                                    int nkeys, ScanKey key,
                                    ParallelTableScanDesc parallel_scan,
                                    uint32 flags);
extern void heap_setscanlimits(TableScanDesc scan, BlockNumber startBlk,
                               BlockNumber numBlks);
extern void heapgetpage(TableScanDesc scan, BlockNumber page);
extern void heap_rescan(TableScanDesc scan, ScanKey key, bool set_params,
                        bool allow_strat, bool allow_sync, bool allow_pagemode);
extern void heap_endscan(TableScanDesc scan);
extern HeapTuple heap_getnext(TableScanDesc scan, ScanDirection direction);
extern bool heap_getnextslot(TableScanDesc sscan,
                             ScanDirection direction, struct TupleTableSlot *slot);

extern bool heap_fetch(Relation relation, Snapshot snapshot,
                       HeapTuple tuple, Buffer *userbuf);
extern bool heap_hot_search_buffer(ItemPointer tid, Relation relation,
                                   Buffer buffer, Snapshot snapshot, HeapTuple heapTuple,
                                   bool *all_dead, bool first_call);

extern void heap_get_latest_tid(TableScanDesc scan, ItemPointer tid);
extern void setLastTid(const ItemPointer tid);

extern BulkInsertState GetBulkInsertState(void);
extern void FreeBulkInsertState(BulkInsertState);
extern void ReleaseBulkInsertStatePin(BulkInsertState bistate);

extern void heap_insert(Relation relation, HeapTuple tup, CommandId cid,
                        int options, BulkInsertState bistate);
extern void heap_multi_insert(Relation relation, struct TupleTableSlot **slots,
                              int ntuples, CommandId cid, int options,
                              BulkInsertState bistate);
extern TM_Result heap_delete(Relation relation, ItemPointer tid,
                             CommandId cid, Snapshot crosscheck, bool wait,
                             struct TM_FailureData *tmfd, bool changingPart);
extern void heap_finish_speculative(Relation relation, ItemPointer tid);
extern void heap_abort_speculative(Relation relation, ItemPointer tid);
extern TM_Result heap_update(Relation relation, ItemPointer otid,
                             HeapTuple newtup,
                             CommandId cid, Snapshot crosscheck, bool wait,
                             struct TM_FailureData *tmfd, LockTupleMode *lockmode);
extern TM_Result heap_lock_tuple(Relation relation, HeapTuple tuple,
                                 CommandId cid, LockTupleMode mode, LockWaitPolicy wait_policy,
                                 bool follow_update,
                                 Buffer *buffer, struct TM_FailureData *tmfd);

extern void heap_inplace_update(Relation relation, HeapTuple tuple);
extern bool heap_freeze_tuple(HeapTupleHeader tuple,
                              TransactionId relfrozenxid, TransactionId relminmxid,
                              TransactionId cutoff_xid, TransactionId cutoff_multi);
extern bool heap_tuple_needs_freeze(HeapTupleHeader tuple, TransactionId cutoff_xid,
                                    MultiXactId cutoff_multi, Buffer buf);
extern bool heap_tuple_needs_eventual_freeze(HeapTupleHeader tuple);

extern void simple_heap_insert(Relation relation, HeapTuple tup);
extern void simple_heap_delete(Relation relation, ItemPointer tid);
extern void simple_heap_update(Relation relation, ItemPointer otid,
                               HeapTuple tup);

extern void heap_sync(Relation relation);

extern TransactionId heap_compute_xid_horizon_for_tuples(Relation rel,
                                                         ItemPointerData *items,
                                                         int nitems);

/* in heap/pruneheap.c */
extern void heap_page_prune_opt(Relation relation, Buffer buffer);
extern int  heap_page_prune(Relation relation, Buffer buffer,
                            TransactionId OldestXmin,
                            bool report_stats, TransactionId *latestRemovedXid);
extern void heap_page_prune_execute(Buffer buffer,
                                    OffsetNumber *redirected, int nredirected,
                                    OffsetNumber *nowdead, int ndead,
                                    OffsetNumber *nowunused, int nunused);
extern void heap_get_root_tuples(Page page, OffsetNumber *root_offsets);

/* in heap/syncscan.c */
extern void ss_report_location(Relation rel, BlockNumber location);
extern BlockNumber ss_get_location(Relation rel, BlockNumber relnblocks);
extern void SyncScanShmemInit(void);
extern Size SyncScanShmemSize(void);

/* in heap/vacuumlazy.c */
struct VacuumParams;
extern void heap_vacuum_rel(Relation onerel,
                            struct VacuumParams *params, BufferAccessStrategy bstrategy);
extern void parallel_vacuum_main(dsm_segment *seg, shm_toc *toc);

/* in heap/heapam_visibility.c */
extern bool HeapTupleSatisfiesVisibility(HeapTuple stup, Snapshot snapshot,
                                         Buffer buffer);
extern TM_Result HeapTupleSatisfiesUpdate(HeapTuple stup, CommandId curcid,
                                          Buffer buffer);
extern HTSV_Result HeapTupleSatisfiesVacuum(HeapTuple stup, TransactionId OldestXmin,
                                            Buffer buffer);
extern void HeapTupleSetHintBits(HeapTupleHeader tuple, Buffer buffer,
                                 uint16 infomask, TransactionId xid);
extern bool HeapTupleHeaderIsOnlyLocked(HeapTupleHeader tuple);
extern bool XidInMVCCSnapshot(TransactionId xid, Snapshot snapshot);
extern bool HeapTupleIsSurelyDead(HeapTuple htup, TransactionId OldestXmin);

/*
 * To avoid leaking too much knowledge about reorderbuffer implementation
 * details this is implemented in reorderbuffer.c not heapam_visibility.c
 */
struct HTAB;
extern bool ResolveCminCmaxDuringDecoding(struct HTAB *tuplecid_data,
                                          Snapshot snapshot,
                                          HeapTuple htup,
                                          Buffer buffer,
                                          CommandId *cmin, CommandId *cmax);

#endif                          /* HEAPAM_H */