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/*-------------------------------------------------------------------------
*
* tqual.h
* POSTGRES "time" qualification definitions, ie, tuple visibility rules.
*
* Should be moved/renamed... - vadim 07/28/98
*
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/utils/tqual.h,v 1.49 2003/11/29 22:41:16 pgsql Exp $
*
*-------------------------------------------------------------------------
*/
#ifndef TQUAL_H
#define TQUAL_H
#include "access/htup.h"
#include "access/xact.h"
typedef struct SnapshotData
{
TransactionId xmin; /* XID < xmin are visible to me */
TransactionId xmax; /* XID >= xmax are invisible to me */
uint32 xcnt; /* # of xact ids in xip[] */
TransactionId *xip; /* array of xact IDs in progress */
/* note: all ids in xip[] satisfy xmin <= xip[i] < xmax */
CommandId curcid; /* in my xact, CID < curcid are visible */
ItemPointerData tid; /* required for Dirty snapshot -:( */
} SnapshotData;
typedef SnapshotData *Snapshot;
#define SnapshotNow ((Snapshot) 0x0)
#define SnapshotSelf ((Snapshot) 0x1)
#define SnapshotAny ((Snapshot) 0x2)
#define SnapshotToast ((Snapshot) 0x3)
extern DLLIMPORT Snapshot SnapshotDirty;
extern DLLIMPORT Snapshot QuerySnapshot;
extern DLLIMPORT Snapshot SerializableSnapshot;
extern TransactionId RecentXmin;
extern TransactionId RecentGlobalXmin;
/*
* HeapTupleSatisfiesVisibility
* True iff heap tuple satisfies a time qual.
*
* Notes:
* Assumes heap tuple is valid.
* Beware of multiple evaluations of snapshot argument.
*/
#define HeapTupleSatisfiesVisibility(tuple, snapshot) \
((snapshot) == SnapshotNow ? \
HeapTupleSatisfiesNow((tuple)->t_data) \
: \
((snapshot) == SnapshotSelf ? \
HeapTupleSatisfiesItself((tuple)->t_data) \
: \
((snapshot) == SnapshotAny ? \
true \
: \
((snapshot) == SnapshotToast ? \
HeapTupleSatisfiesToast((tuple)->t_data) \
: \
((snapshot) == SnapshotDirty ? \
HeapTupleSatisfiesDirty((tuple)->t_data) \
: \
HeapTupleSatisfiesSnapshot((tuple)->t_data, snapshot) \
) \
) \
) \
) \
)
/* Result codes for HeapTupleSatisfiesUpdate */
#define HeapTupleMayBeUpdated 0
#define HeapTupleInvisible 1
#define HeapTupleSelfUpdated 2
#define HeapTupleUpdated 3
#define HeapTupleBeingUpdated 4
/* 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;
extern bool HeapTupleSatisfiesItself(HeapTupleHeader tuple);
extern bool HeapTupleSatisfiesNow(HeapTupleHeader tuple);
extern bool HeapTupleSatisfiesDirty(HeapTupleHeader tuple);
extern bool HeapTupleSatisfiesToast(HeapTupleHeader tuple);
extern bool HeapTupleSatisfiesSnapshot(HeapTupleHeader tuple,
Snapshot snapshot);
extern int HeapTupleSatisfiesUpdate(HeapTupleHeader tuple,
CommandId curcid);
extern HTSV_Result HeapTupleSatisfiesVacuum(HeapTupleHeader tuple,
TransactionId OldestXmin);
extern Snapshot GetSnapshotData(Snapshot snapshot, bool serializable);
extern void SetQuerySnapshot(void);
extern Snapshot CopyQuerySnapshot(void);
extern Snapshot CopyCurrentSnapshot(void);
extern void FreeXactSnapshot(void);
#endif /* TQUAL_H */
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