Create a new HeapTupleSatisfiesVacuum() routine in tqual.c that embodies the

validity checking rules for VACUUM.  Make some other rearrangements of the
VACUUM code to allow more code to be shared between full and lazy VACUUM.
Minor code cleanups and added comments for TransactionId manipulations.

1 files changed, 23 insertions, 9 deletions

diff --git a/src/include/utils/tqual.h b/src/include/utils/tqual.h
index 7c3dece02fe..86c88892adf 100644
--- a/src/include/utils/tqual.h
+++ b/src/include/utils/tqual.h
@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: tqual.h,v 1.31 2001/06/18 21:38:02 momjian Exp $
+ * $Id: tqual.h,v 1.32 2001/07/12 04:11:13 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -23,8 +23,9 @@ typedef struct SnapshotData
 {
 	TransactionId xmin;			/* XID < xmin are visible to me */
 	TransactionId xmax;			/* XID >= xmax are invisible to me */
-	uint32		xcnt;			/* # of xact below */
-	TransactionId *xip;			/* array of xacts in progress */
+	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 */
 	ItemPointerData tid;		/* required for Dirty snapshot -:( */
 } SnapshotData;
 
@@ -34,8 +35,8 @@ typedef SnapshotData *Snapshot;
 #define SnapshotSelf				((Snapshot) 0x1)
 #define SnapshotAny					((Snapshot) 0x2)
 
-extern Snapshot SnapshotDirty;
-extern Snapshot QuerySnapshot;
+extern DLLIMPORT Snapshot SnapshotDirty;
+extern DLLIMPORT Snapshot QuerySnapshot;
 extern DLLIMPORT Snapshot SerializableSnapshot;
 
 extern bool ReferentialIntegritySnapshotOverride;
@@ -66,11 +67,11 @@ extern bool ReferentialIntegritySnapshotOverride;
 			(IsSnapshotSelf(snapshot) ? \
 				HeapTupleSatisfiesItself((tuple)->t_data) \
 			: \
-				(IsSnapshotDirty(snapshot) ? \
-					HeapTupleSatisfiesDirty((tuple)->t_data) \
+				(IsSnapshotNow(snapshot) ? \
+					HeapTupleSatisfiesNow((tuple)->t_data) \
 				: \
-					(IsSnapshotNow(snapshot) ? \
-						HeapTupleSatisfiesNow((tuple)->t_data) \
+					(IsSnapshotDirty(snapshot) ? \
+						HeapTupleSatisfiesDirty((tuple)->t_data) \
 					: \
 						HeapTupleSatisfiesSnapshot((tuple)->t_data, snapshot) \
 					) \
@@ -79,18 +80,31 @@ extern bool ReferentialIntegritySnapshotOverride;
 	) \
 )
 
+/* 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 HeapTupleSatisfiesSnapshot(HeapTupleHeader tuple,
 						   Snapshot snapshot);
 extern int	HeapTupleSatisfiesUpdate(HeapTuple tuple);
+extern HTSV_Result HeapTupleSatisfiesVacuum(HeapTupleHeader tuple,
+											TransactionId XmaxRecent);
 
 extern Snapshot GetSnapshotData(bool serializable);
 extern void SetQuerySnapshot(void);