simplehash: Allow use of simplehash without MemoryContext.
If the SH_RAW_ALLOCATOR is defined, it will be used to allocate bytes
for the hash table, and no dependencies on MemoryContext will exist.
This means, in particular, that the SH_CREATE function will not take
a MemoryContext argument.
Patch by me,
Discussion:
* - SH_DEFINE - if defined function definitions are generated
* - SH_SCOPE - in which scope (e.g. extern, static inline) do function
* declarations reside
+ * - SH_RAW_ALLOCATOR - if defined, memory contexts are not used; instead,
+ * use this to allocate bytes
* - SH_USE_NONDEFAULT_ALLOCATOR - if defined no element allocator functions
* are defined, so you can supply your own
* The following parameters are only relevant when SH_DEFINE is defined:
@@ -121,8 +123,10 @@ typedef struct SH_TYPE
/* hash buckets */
SH_ELEMENT_TYPE *data;
+#ifndef SH_RAW_ALLOCATOR
/* memory context to use for allocations */
MemoryContext ctx;
+#endif
/* user defined data, useful for callbacks */
void *private_data;
@@ -142,8 +146,12 @@ typedef struct SH_ITERATOR
} SH_ITERATOR;
/* externally visible function prototypes */
+#ifdef SH_RAW_ALLOCATOR
+SH_SCOPE SH_TYPE *SH_CREATE(uint32 nelements, void *private_data);
+#else
SH_SCOPE SH_TYPE *SH_CREATE(MemoryContext ctx, uint32 nelements,
void *private_data);
+#endif
SH_SCOPE void SH_DESTROY(SH_TYPE * tb);
SH_SCOPE void SH_RESET(SH_TYPE * tb);
SH_SCOPE void SH_GROW(SH_TYPE * tb, uint32 newsize);
@@ -165,7 +173,9 @@ SH_SCOPE void SH_STAT(SH_TYPE * tb);
/* generate implementation of the hash table */
#ifdef SH_DEFINE
+#ifndef SH_RAW_ALLOCATOR
#include "utils/memutils.h"
+#endif
/* max data array size,we allow up to PG_UINT32_MAX buckets, including 0 */
#define SH_MAX_SIZE (((uint64) PG_UINT32_MAX) + 1)
@@ -328,8 +338,12 @@ static inline void SH_FREE(SH_TYPE * type, void *pointer);
static inline void *
SH_ALLOCATE(SH_TYPE * type, Size size)
{
+#ifdef SH_RAW_ALLOCATOR
+ return SH_RAW_ALLOCATOR(size);
+#else
return MemoryContextAllocExtended(type->ctx, size,
MCXT_ALLOC_HUGE | MCXT_ALLOC_ZERO);
+#endif
}
/* default memory free function */
@@ -350,14 +364,23 @@ SH_FREE(SH_TYPE * type, void *pointer)
* Memory other than for the array of elements will still be allocated from
* the passed-in context.
*/
+#ifdef SH_RAW_ALLOCATOR
+SH_SCOPE SH_TYPE *
+SH_CREATE(uint32 nelements, void *private_data)
+#else
SH_SCOPE SH_TYPE *
SH_CREATE(MemoryContext ctx, uint32 nelements, void *private_data)
+#endif
{
SH_TYPE *tb;
uint64 size;
+#ifdef SH_RAW_ALLOCATOR
+ tb = SH_RAW_ALLOCATOR(sizeof(SH_TYPE));
+#else
tb = MemoryContextAllocZero(ctx, sizeof(SH_TYPE));
tb->ctx = ctx;
+#endif
tb->private_data = private_data;
/* increase nelements by fillfactor, want to store nelements elements */
