trAvis - MANAGER

Edit File: tqual.h

/*------------------------------------------------------------------------- * * tqual.h * POSTGRES "time qualification" definitions, ie, tuple visibility rules. * * Should be moved/renamed... - vadim 07/28/98 * * Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * src/include/utils/tqual.h * *------------------------------------------------------------------------- */ #ifndef TQUAL_H #define TQUAL_H #include "utils/snapshot.h" /* Static variables representing various special snapshot semantics */ extern PGDLLIMPORT SnapshotData SnapshotNowData; extern PGDLLIMPORT SnapshotData SnapshotSelfData; extern PGDLLIMPORT SnapshotData SnapshotAnyData; extern PGDLLIMPORT SnapshotData SnapshotToastData; #define SnapshotNow (&SnapshotNowData) #define SnapshotSelf (&SnapshotSelfData) #define SnapshotAny (&SnapshotAnyData) #define SnapshotToast (&SnapshotToastData) /* * We don't provide a static SnapshotDirty variable because it would be * non-reentrant. Instead, users of that snapshot type should declare a * local variable of type SnapshotData, and initialize it with this macro. */ #define InitDirtySnapshot(snapshotdata) \ ((snapshotdata).satisfies = HeapTupleSatisfiesDirty) /* This macro encodes the knowledge of which snapshots are MVCC-safe */ #define IsMVCCSnapshot(snapshot) \ ((snapshot)->satisfies == HeapTupleSatisfiesMVCC) /* * HeapTupleSatisfiesVisibility * True iff heap tuple satisfies a time qual. * * Notes: * Assumes heap tuple is valid. * Beware of multiple evaluations of snapshot argument. * Hint bits in the HeapTuple's t_infomask may be updated as a side effect; * if so, the indicated buffer is marked dirty. */ #define HeapTupleSatisfiesVisibility(tuple, snapshot, buffer) \ ((*(snapshot)->satisfies) ((tuple)->t_data, snapshot, buffer)) /* 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; /* These are the "satisfies" test routines for the various snapshot types */ extern bool HeapTupleSatisfiesMVCC(HeapTupleHeader tuple, Snapshot snapshot, Buffer buffer); extern bool HeapTupleSatisfiesNow(HeapTupleHeader tuple, Snapshot snapshot, Buffer buffer); extern bool HeapTupleSatisfiesSelf(HeapTupleHeader tuple, Snapshot snapshot, Buffer buffer); extern bool HeapTupleSatisfiesAny(HeapTupleHeader tuple, Snapshot snapshot, Buffer buffer); extern bool HeapTupleSatisfiesToast(HeapTupleHeader tuple, Snapshot snapshot, Buffer buffer); extern bool HeapTupleSatisfiesDirty(HeapTupleHeader tuple, Snapshot snapshot, Buffer buffer); /* Special "satisfies" routines with different APIs */ extern HTSU_Result HeapTupleSatisfiesUpdate(HeapTupleHeader tuple, CommandId curcid, Buffer buffer); extern HTSV_Result HeapTupleSatisfiesVacuum(HeapTupleHeader tuple, TransactionId OldestXmin, Buffer buffer); extern bool HeapTupleIsSurelyDead(HeapTupleHeader tuple, TransactionId OldestXmin); extern bool XidInMVCCSnapshot(TransactionId xid, Snapshot snapshot); extern void HeapTupleSetHintBits(HeapTupleHeader tuple, Buffer buffer, uint16 infomask, TransactionId xid); #endif /* TQUAL_H */