contrib/tre/lib/tre-mem.h

   1 /*
   2   tre-mem.h - TRE memory allocator interface
   3
   4   This software is released under a BSD-style license.
   5   See the file LICENSE for details and copyright.
   6
   7 */
   8
   9 #ifndef TRE_MEM_H
  10 #define TRE_MEM_H 1
  11
  12 #include <stdlib.h>
  13
  14 #define TRE_MEM_BLOCK_SIZE 1024
  15
  16 typedef struct tre_list {
  17   void *data;
  18   struct tre_list *next;
  19 } tre_list_t;
  20
  21 typedef struct tre_mem_struct {
  22   tre_list_t *blocks;
  23   tre_list_t *current;
  24   char *ptr;
  25   size_t n;
  26   int failed;
  27   void **provided;
  28 } *tre_mem_t;
  29
  30
  31 tre_mem_t tre_mem_new_impl(int provided, void *provided_block);
  32 void *tre_mem_alloc_impl(tre_mem_t mem, int provided, void *provided_block,
  33                          int zero, size_t size);
  34
  35 /* Returns a new memory allocator or NULL if out of memory. */
  36 #define tre_mem_new()  tre_mem_new_impl(0, NULL)
  37
  38 /* Allocates a block of `size' bytes from `mem'.  Returns a pointer to the
  39    allocated block or NULL if an underlying malloc() failed. */
  40 #define tre_mem_alloc(mem, size) tre_mem_alloc_impl(mem, 0, NULL, 0, size)
  41
  42 /* Allocates a block of `size' bytes from `mem'.  Returns a pointer to the
  43    allocated block or NULL if an underlying malloc() failed.  The memory
  44    is set to zero. */
  45 #define tre_mem_calloc(mem, size) tre_mem_alloc_impl(mem, 0, NULL, 1, size)
  46
  47 #ifdef TRE_USE_ALLOCA
  48 /* alloca() versions.  Like above, but memory is allocated with alloca()
  49    instead of malloc(). */
  50
  51 #define tre_mem_newa() \
  52   tre_mem_new_impl(1, alloca(sizeof(struct tre_mem_struct)))
  53
  54 #define tre_mem_alloca(mem, size)                                             \
  55   ((mem)->n >= (size)                                                         \
  56    ? tre_mem_alloc_impl((mem), 1, NULL, 0, (size))                            \
  57    : tre_mem_alloc_impl((mem), 1, alloca(TRE_MEM_BLOCK_SIZE), 0, (size)))
  58 #endif /* TRE_USE_ALLOCA */
  59
  60
  61 /* Frees the memory allocator and all memory allocated with it. */
  62 void tre_mem_destroy(tre_mem_t mem);
  63
  64 #endif /* TRE_MEM_H */
  65
  66 /* EOF */