regex/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 __private_extern__ tre_mem_t tre_mem_new_impl(int provided,
  32                                               void *provided_block);
  33 __private_extern__ void *tre_mem_alloc_impl(tre_mem_t mem, int provided,
  34                                             void *provided_block,
  35                                             int zero, size_t size);
  36
  37 /* Returns a new memory allocator or NULL if out of memory. */
  38 #define tre_mem_new()  tre_mem_new_impl(0, NULL)
  39
  40 /* Allocates a block of `size' bytes from `mem'.  Returns a pointer to the
  41    allocated block or NULL if an underlying malloc() failed. */
  42 #define tre_mem_alloc(mem, size) tre_mem_alloc_impl(mem, 0, NULL, 0, size)
  43
  44 /* Allocates a block of `size' bytes from `mem'.  Returns a pointer to the
  45    allocated block or NULL if an underlying malloc() failed.  The memory
  46    is set to zero. */
  47 #define tre_mem_calloc(mem, size) tre_mem_alloc_impl(mem, 0, NULL, 1, size)
  48
  49 #ifdef TRE_USE_ALLOCA
  50 /* alloca() versions.  Like above, but memory is allocated with alloca()
  51    instead of malloc(). */
  52
  53 #define tre_mem_newa() \
  54   tre_mem_new_impl(1, alloca(sizeof(struct tre_mem_struct)))
  55
  56 #define tre_mem_alloca(mem, size)                                             \
  57   ((mem)->n >= (size)                                                         \
  58    ? tre_mem_alloc_impl((mem), 1, NULL, 0, (size))                            \
  59    : tre_mem_alloc_impl((mem), 1, alloca(TRE_MEM_BLOCK_SIZE), 0, (size)))
  60 #endif /* TRE_USE_ALLOCA */
  61
  62
  63 /* Frees the memory allocator and all memory allocated with it. */
  64 __private_extern__ void tre_mem_destroy(tre_mem_t mem);
  65
  66 #endif /* TRE_MEM_H */
  67
  68 /* EOF */