Andrew's git - gitweb.git/blob - vcs-svn/obj

   1/*
   2 * Licensed under a two-clause BSD-style license.
   3 * See LICENSE for details.
   4 */
   5
   6#ifndef OBJ_POOL_H_
   7#define OBJ_POOL_H_
   8
   9#include "git-compat-util.h"
  10
  11#define MAYBE_UNUSED __attribute__((__unused__))
  12
  13#define obj_pool_gen(pre, obj_t, initial_capacity) \
  14static struct { \
  15        uint32_t committed; \
  16        uint32_t size; \
  17        uint32_t capacity; \
  18        obj_t *base; \
  19} pre##_pool = {0, 0, 0, NULL}; \
  20static MAYBE_UNUSED uint32_t pre##_alloc(uint32_t count) \
  21{ \
  22        uint32_t offset; \
  23        if (pre##_pool.size + count > pre##_pool.capacity) { \
  24                while (pre##_pool.size + count > pre##_pool.capacity) \
  25                        if (pre##_pool.capacity) \
  26                                pre##_pool.capacity *= 2; \
  27                        else \
  28                                pre##_pool.capacity = initial_capacity; \
  29                pre##_pool.base = realloc(pre##_pool.base, \
  30                                        pre##_pool.capacity * sizeof(obj_t)); \
  31        } \
  32        offset = pre##_pool.size; \
  33        pre##_pool.size += count; \
  34        return offset; \
  35} \
  36static MAYBE_UNUSED void pre##_free(uint32_t count) \
  37{ \
  38        pre##_pool.size -= count; \
  39} \
  40static MAYBE_UNUSED uint32_t pre##_offset(obj_t *obj) \
  41{ \
  42        return obj == NULL ? ~0 : obj - pre##_pool.base; \
  43} \
  44static MAYBE_UNUSED obj_t *pre##_pointer(uint32_t offset) \
  45{ \
  46        return offset >= pre##_pool.size ? NULL : &pre##_pool.base[offset]; \
  47} \
  48static MAYBE_UNUSED void pre##_commit(void) \
  49{ \
  50        pre##_pool.committed = pre##_pool.size; \
  51} \
  52static MAYBE_UNUSED void pre##_reset(void) \
  53{ \
  54        free(pre##_pool.base); \
  55        pre##_pool.base = NULL; \
  56        pre##_pool.size = 0; \
  57        pre##_pool.capacity = 0; \
  58        pre##_pool.committed = 0; \
  59}
  60
  61#endif