Change dynahash.c and hsearch.h to use int64 instead of long

michaelpq · michaelpq · commit 13b935cd5217 · 2025-08-22T11:59:02.000+09:00
This code was relying on "long", which is signed 8 bytes everywhere except on Windows where it is 4 bytes, that could potentially expose it to overflows, even if the current uses in the code are fine as far as I know. This code is now able to rely on the same sizeof() variable everywhere, with int64. long was used for sizes, partition counts and entry counts. Some callers of the dynahash.c routines used long declarations, that can be cleaned up to use int64 instead. There was one shortcut based on SIZEOF_LONG, that can be removed. long is entirely removed from dynahash.c and hsearch.h. Similar work was done in b1e5c9f. Reviewed-by: Peter Eisentraut <peter@eisentraut.org> Reviewed-by: Chao Li <li.evan.chao@gmail.com> Discussion: https://postgr.es/m/aKQYp-bKTRtRauZ6@paquier.xyz
diff --git a/contrib/pg_stat_statements/pg_stat_statements.c b/contrib/pg_stat_statements/pg_stat_statements.c
@@ -2713,8 +2713,8 @@ entry_reset(Oid userid, Oid dbid, int64 queryid, bool minmax_only)
 	HASH_SEQ_STATUS hash_seq;
 	pgssEntry  *entry;
 	FILE	   *qfile;
-	long		num_entries;
-	long		num_remove = 0;
+	int64		num_entries;
+	int64		num_remove = 0;
 	pgssHashKey key;
 	TimestampTz stats_reset;
 
diff --git a/src/backend/catalog/storage.c b/src/backend/catalog/storage.c
@@ -586,7 +586,7 @@ RelFileLocatorSkippingWAL(RelFileLocator rlocator)
 Size
 EstimatePendingSyncsSpace(void)
 {
-	long		entries;
+	int64		entries;
 
 	entries = pendingSyncHash ? hash_get_num_entries(pendingSyncHash) : 0;
 	return mul_size(1 + entries, sizeof(RelFileLocator));
diff --git a/src/backend/storage/ipc/shmem.c b/src/backend/storage/ipc/shmem.c
@@ -330,8 +330,8 @@ InitShmemIndex(void)
  */
 HTAB *
 ShmemInitHash(const char *name,		/* table string name for shmem index */
-			  long init_size,	/* initial table size */
-			  long max_size,	/* max size of the table */
+			  int64 init_size,	/* initial table size */
+			  int64 max_size,	/* max size of the table */
 			  HASHCTL *infoP,	/* info about key and bucket size */
 			  int hash_flags)	/* info about infoP */
 {
diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c
@@ -443,7 +443,7 @@ void
 LockManagerShmemInit(void)
 {
 	HASHCTL		info;
-	long		init_table_size,
+	int64		init_table_size,
 				max_table_size;
 	bool		found;
 
diff --git a/src/backend/storage/lmgr/predicate.c b/src/backend/storage/lmgr/predicate.c
@@ -1145,7 +1145,7 @@ void
 PredicateLockShmemInit(void)
 {
 	HASHCTL		info;
-	long		max_table_size;
+	int64		max_table_size;
 	Size		requestSize;
 	bool		found;
 
diff --git a/src/backend/utils/hash/dynahash.c b/src/backend/utils/hash/dynahash.c
@@ -154,7 +154,7 @@ typedef HASHBUCKET *HASHSEGMENT;
 typedef struct
 {
 	slock_t		mutex;			/* spinlock for this freelist */
-	long		nentries;		/* number of entries in associated buckets */
+	int64		nentries;		/* number of entries in associated buckets */
 	HASHELEMENT *freeList;		/* chain of free elements */
 } FreeListData;
 
@@ -182,18 +182,18 @@ struct HASHHDR
 
 	/* These fields can change, but not in a partitioned table */
 	/* Also, dsize can't change in a shared table, even if unpartitioned */
-	long		dsize;			/* directory size */
-	long		nsegs;			/* number of allocated segments (<= dsize) */
+	int64		dsize;			/* directory size */
+	int64		nsegs;			/* number of allocated segments (<= dsize) */
 	uint32		max_bucket;		/* ID of maximum bucket in use */
 	uint32		high_mask;		/* mask to modulo into entire table */
 	uint32		low_mask;		/* mask to modulo into lower half of table */
 
 	/* These fields are fixed at hashtable creation */
 	Size		keysize;		/* hash key length in bytes */
 	Size		entrysize;		/* total user element size in bytes */
-	long		num_partitions; /* # partitions (must be power of 2), or 0 */
-	long		max_dsize;		/* 'dsize' limit if directory is fixed size */
-	long		ssize;			/* segment size --- must be power of 2 */
+	int64		num_partitions; /* # partitions (must be power of 2), or 0 */
+	int64		max_dsize;		/* 'dsize' limit if directory is fixed size */
+	int64		ssize;			/* segment size --- must be power of 2 */
 	int			sshift;			/* segment shift = log2(ssize) */
 	int			nelem_alloc;	/* number of entries to allocate at once */
 	bool		isfixed;		/* if true, don't enlarge */
@@ -236,7 +236,7 @@ struct HTAB
 
 	/* We keep local copies of these fixed values to reduce contention */
 	Size		keysize;		/* hash key length in bytes */
-	long		ssize;			/* segment size --- must be power of 2 */
+	int64		ssize;			/* segment size --- must be power of 2 */
 	int			sshift;			/* segment shift = log2(ssize) */
 
 	/*
@@ -277,12 +277,12 @@ static bool expand_table(HTAB *hashp);
 static HASHBUCKET get_hash_entry(HTAB *hashp, int freelist_idx);
 static void hdefault(HTAB *hashp);
 static int	choose_nelem_alloc(Size entrysize);
-static bool init_htab(HTAB *hashp, long nelem);
+static bool init_htab(HTAB *hashp, int64 nelem);
 pg_noreturn static void hash_corrupted(HTAB *hashp);
 static uint32 hash_initial_lookup(HTAB *hashp, uint32 hashvalue,
 								  HASHBUCKET **bucketptr);
-static long next_pow2_long(long num);
-static int	next_pow2_int(long num);
+static int64 next_pow2_int64(int64 num);
+static int	next_pow2_int(int64 num);
 static void register_seq_scan(HTAB *hashp);
 static void deregister_seq_scan(HTAB *hashp);
 static bool has_seq_scans(HTAB *hashp);
@@ -355,7 +355,7 @@ string_compare(const char *key1, const char *key2, Size keysize)
  * large nelem will penalize hash_seq_search speed without buying much.
  */
 HTAB *
-hash_create(const char *tabname, long nelem, const HASHCTL *info, int flags)
+hash_create(const char *tabname, int64 nelem, const HASHCTL *info, int flags)
 {
 	HTAB	   *hashp;
 	HASHHDR    *hctl;
@@ -697,7 +697,7 @@ choose_nelem_alloc(Size entrysize)
  * arrays
  */
 static bool
-init_htab(HTAB *hashp, long nelem)
+init_htab(HTAB *hashp, int64 nelem)
 {
 	HASHHDR    *hctl = hashp->hctl;
 	HASHSEGMENT *segp;
@@ -780,20 +780,20 @@ init_htab(HTAB *hashp, long nelem)
  * NB: assumes that all hash structure parameters have default values!
  */
 Size
-hash_estimate_size(long num_entries, Size entrysize)
+hash_estimate_size(int64 num_entries, Size entrysize)
 {
 	Size		size;
-	long		nBuckets,
+	int64		nBuckets,
 				nSegments,
 				nDirEntries,
 				nElementAllocs,
 				elementSize,
 				elementAllocCnt;
 
 	/* estimate number of buckets wanted */
-	nBuckets = next_pow2_long(num_entries);
+	nBuckets = next_pow2_int64(num_entries);
 	/* # of segments needed for nBuckets */
-	nSegments = next_pow2_long((nBuckets - 1) / DEF_SEGSIZE + 1);
+	nSegments = next_pow2_int64((nBuckets - 1) / DEF_SEGSIZE + 1);
 	/* directory entries */
 	nDirEntries = DEF_DIRSIZE;
 	while (nDirEntries < nSegments)
@@ -826,17 +826,17 @@ hash_estimate_size(long num_entries, Size entrysize)
  *
  * XXX this had better agree with the behavior of init_htab()...
  */
-long
-hash_select_dirsize(long num_entries)
+int64
+hash_select_dirsize(int64 num_entries)
 {
-	long		nBuckets,
+	int64		nBuckets,
 				nSegments,
 				nDirEntries;
 
 	/* estimate number of buckets wanted */
-	nBuckets = next_pow2_long(num_entries);
+	nBuckets = next_pow2_int64(num_entries);
 	/* # of segments needed for nBuckets */
-	nSegments = next_pow2_long((nBuckets - 1) / DEF_SEGSIZE + 1);
+	nSegments = next_pow2_int64((nBuckets - 1) / DEF_SEGSIZE + 1);
 	/* directory entries */
 	nDirEntries = DEF_DIRSIZE;
 	while (nDirEntries < nSegments)
@@ -887,7 +887,7 @@ hash_stats(const char *caller, HTAB *hashp)
 	HASHHDR    *hctl = hashp->hctl;
 
 	elog(DEBUG4,
-		 "hash_stats:  Caller: %s  Table Name: \"%s\"  Accesses: " UINT64_FORMAT "  Collisions: " UINT64_FORMAT "  Expansions: " UINT64_FORMAT "  Entries: %ld  Key Size: %zu  Max Bucket: %u  Segment Count: %ld",
+		 "hash_stats:  Caller: %s  Table Name: \"%s\"  Accesses: " UINT64_FORMAT "  Collisions: " UINT64_FORMAT "  Expansions: " UINT64_FORMAT "  Entries: " INT64_FORMAT "  Key Size: %zu  Max Bucket: %u  Segment Count: " INT64_FORMAT,
 		 caller != NULL ? caller : "(unknown)", hashp->tabname, hctl->accesses,
 		 hctl->collisions, hctl->expansions, hash_get_num_entries(hashp),
 		 hctl->keysize, hctl->max_bucket, hctl->nsegs);
@@ -993,7 +993,7 @@ hash_search_with_hash_value(HTAB *hashp,
 		 * Can't split if running in partitioned mode, nor if frozen, nor if
 		 * table is the subject of any active hash_seq_search scans.
 		 */
-		if (hctl->freeList[0].nentries > (long) hctl->max_bucket &&
+		if (hctl->freeList[0].nentries > (int64) hctl->max_bucket &&
 			!IS_PARTITIONED(hctl) && !hashp->frozen &&
 			!has_seq_scans(hashp))
 			(void) expand_table(hashp);
@@ -1332,11 +1332,11 @@ get_hash_entry(HTAB *hashp, int freelist_idx)
 /*
  * hash_get_num_entries -- get the number of entries in a hashtable
  */
-long
+int64
 hash_get_num_entries(HTAB *hashp)
 {
 	int			i;
-	long		sum = hashp->hctl->freeList[0].nentries;
+	int64		sum = hashp->hctl->freeList[0].nentries;
 
 	/*
 	 * We currently don't bother with acquiring the mutexes; it's only
@@ -1417,9 +1417,9 @@ hash_seq_search(HASH_SEQ_STATUS *status)
 	HTAB	   *hashp;
 	HASHHDR    *hctl;
 	uint32		max_bucket;
-	long		ssize;
-	long		segment_num;
-	long		segment_ndx;
+	int64		ssize;
+	int64		segment_num;
+	int64		segment_ndx;
 	HASHSEGMENT segp;
 	uint32		curBucket;
 	HASHELEMENT *curElem;
@@ -1548,11 +1548,11 @@ expand_table(HTAB *hashp)
 	HASHHDR    *hctl = hashp->hctl;
 	HASHSEGMENT old_seg,
 				new_seg;
-	long		old_bucket,
+	int64		old_bucket,
 				new_bucket;
-	long		new_segnum,
+	int64		new_segnum,
 				new_segndx;
-	long		old_segnum,
+	int64		old_segnum,
 				old_segndx;
 	HASHBUCKET *oldlink,
 			   *newlink;
@@ -1620,7 +1620,7 @@ expand_table(HTAB *hashp)
 		 currElement = nextElement)
 	{
 		nextElement = currElement->link;
-		if ((long) calc_bucket(hctl, currElement->hashvalue) == old_bucket)
+		if ((int64) calc_bucket(hctl, currElement->hashvalue) == old_bucket)
 		{
 			*oldlink = currElement;
 			oldlink = &currElement->link;
@@ -1644,9 +1644,9 @@ dir_realloc(HTAB *hashp)
 {
 	HASHSEGMENT *p;
 	HASHSEGMENT *old_p;
-	long		new_dsize;
-	long		old_dirsize;
-	long		new_dirsize;
+	int64		new_dsize;
+	int64		old_dirsize;
+	int64		new_dirsize;
 
 	if (hashp->hctl->max_dsize != NO_MAX_DSIZE)
 		return false;
@@ -1780,8 +1780,8 @@ hash_initial_lookup(HTAB *hashp, uint32 hashvalue, HASHBUCKET **bucketptr)
 {
 	HASHHDR    *hctl = hashp->hctl;
 	HASHSEGMENT segp;
-	long		segment_num;
-	long		segment_ndx;
+	int64		segment_num;
+	int64		segment_ndx;
 	uint32		bucket;
 
 	bucket = calc_bucket(hctl, hashvalue);
@@ -1814,33 +1814,29 @@ hash_corrupted(HTAB *hashp)
 
 /* calculate ceil(log base 2) of num */
 int
-my_log2(long num)
+my_log2(int64 num)
 {
 	/*
 	 * guard against too-large input, which would be invalid for
 	 * pg_ceil_log2_*()
 	 */
-	if (num > LONG_MAX / 2)
-		num = LONG_MAX / 2;
+	if (num > PG_INT64_MAX / 2)
+		num = PG_INT64_MAX / 2;
 
-#if SIZEOF_LONG < 8
-	return pg_ceil_log2_32(num);
-#else
 	return pg_ceil_log2_64(num);
-#endif
 }
 
-/* calculate first power of 2 >= num, bounded to what will fit in a long */
-static long
-next_pow2_long(long num)
+/* calculate first power of 2 >= num, bounded to what will fit in a int64 */
+static int64
+next_pow2_int64(int64 num)
 {
 	/* my_log2's internal range check is sufficient */
 	return 1L << my_log2(num);
 }
 
 /* calculate first power of 2 >= num, bounded to what will fit in an int */
 static int
-next_pow2_int(long num)
+next_pow2_int(int64 num)
 {
 	if (num > INT_MAX / 2)
 		num = INT_MAX / 2;
diff --git a/src/include/storage/shmem.h b/src/include/storage/shmem.h
@@ -35,7 +35,7 @@ extern void *ShmemAllocNoError(Size size);
 extern void *ShmemAllocUnlocked(Size size);
 extern bool ShmemAddrIsValid(const void *addr);
 extern void InitShmemIndex(void);
-extern HTAB *ShmemInitHash(const char *name, long init_size, long max_size,
+extern HTAB *ShmemInitHash(const char *name, int64 init_size, int64 max_size,
 						   HASHCTL *infoP, int hash_flags);
 extern void *ShmemInitStruct(const char *name, Size size, bool *foundPtr);
 extern Size add_size(Size s1, Size s2);
diff --git a/src/include/utils/dynahash.h b/src/include/utils/dynahash.h
@@ -15,6 +15,6 @@
 #ifndef DYNAHASH_H
 #define DYNAHASH_H
 
-extern int	my_log2(long num);
+extern int	my_log2(int64 num);
 
 #endif							/* DYNAHASH_H */
diff --git a/src/include/utils/hsearch.h b/src/include/utils/hsearch.h
@@ -65,12 +65,12 @@ typedef struct HTAB HTAB;
 typedef struct HASHCTL
 {
 	/* Used if HASH_PARTITION flag is set: */
-	long		num_partitions; /* # partitions (must be power of 2) */
+	int64		num_partitions; /* # partitions (must be power of 2) */
 	/* Used if HASH_SEGMENT flag is set: */
-	long		ssize;			/* segment size */
+	int64		ssize;			/* segment size */
 	/* Used if HASH_DIRSIZE flag is set: */
-	long		dsize;			/* (initial) directory size */
-	long		max_dsize;		/* limit to dsize if dir size is limited */
+	int64		dsize;			/* (initial) directory size */
+	int64		max_dsize;		/* limit to dsize if dir size is limited */
 	/* Used if HASH_ELEM flag is set (which is now required): */
 	Size		keysize;		/* hash key length in bytes */
 	Size		entrysize;		/* total user element size in bytes */
@@ -129,7 +129,7 @@ typedef struct
 /*
  * prototypes for functions in dynahash.c
  */
-extern HTAB *hash_create(const char *tabname, long nelem,
+extern HTAB *hash_create(const char *tabname, int64 nelem,
 						 const HASHCTL *info, int flags);
 extern void hash_destroy(HTAB *hashp);
 extern void hash_stats(const char *caller, HTAB *hashp);
@@ -141,16 +141,16 @@ extern void *hash_search_with_hash_value(HTAB *hashp, const void *keyPtr,
 										 bool *foundPtr);
 extern bool hash_update_hash_key(HTAB *hashp, void *existingEntry,
 								 const void *newKeyPtr);
-extern long hash_get_num_entries(HTAB *hashp);
+extern int64 hash_get_num_entries(HTAB *hashp);
 extern void hash_seq_init(HASH_SEQ_STATUS *status, HTAB *hashp);
 extern void hash_seq_init_with_hash_value(HASH_SEQ_STATUS *status,
 										  HTAB *hashp,
 										  uint32 hashvalue);
 extern void *hash_seq_search(HASH_SEQ_STATUS *status);
 extern void hash_seq_term(HASH_SEQ_STATUS *status);
 extern void hash_freeze(HTAB *hashp);
-extern Size hash_estimate_size(long num_entries, Size entrysize);
-extern long hash_select_dirsize(long num_entries);
+extern Size hash_estimate_size(int64 num_entries, Size entrysize);
+extern int64 hash_select_dirsize(int64 num_entries);
 extern Size hash_get_shared_size(HASHCTL *info, int flags);
 extern void AtEOXact_HashTables(bool isCommit);
 extern void AtEOSubXact_HashTables(bool isCommit, int nestDepth);

Original file line number	Diff line number	Diff line change
`@@ -586,7 +586,7 @@ RelFileLocatorSkippingWAL(RelFileLocator rlocator)`
`586`	`586`	`Size`
`587`	`587`	`EstimatePendingSyncsSpace(void)`
`588`	`588`	`{`
`589`		`- long entries;`
	`589`	`+ int64 entries;`
`590`	`590`
`591`	`591`	`entries = pendingSyncHash ? hash_get_num_entries(pendingSyncHash) : 0;`
`592`	`592`	`return mul_size(1 + entries, sizeof(RelFileLocator));`
Original file line number	Diff line number	Diff line change
`@@ -443,7 +443,7 @@ void`
`443`	`443`	`LockManagerShmemInit(void)`
`444`	`444`	`{`
`445`	`445`	`HASHCTL info;`
`446`		`- long init_table_size,`
	`446`	`+ int64 init_table_size,`
`447`	`447`	`max_table_size;`
`448`	`448`	`bool found;`
`449`	`449`
Original file line number	Diff line number	Diff line change
`@@ -1145,7 +1145,7 @@ void`
`1145`	`1145`	`PredicateLockShmemInit(void)`
`1146`	`1146`	`{`
`1147`	`1147`	`HASHCTL info;`
`1148`		`- long max_table_size;`
	`1148`	`+ int64 max_table_size;`
`1149`	`1149`	`Size requestSize;`
`1150`	`1150`	`bool found;`
`1151`	`1151`