Dogcows Code - chaz/yoink/blob - yajl/src/yajl_bytestack.h

   1 /*
   2  * Copyright 2009, Lloyd Hilaiel.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are
   6  * met:
   7  *
   8  *  1. Redistributions of source code must retain the above copyright
   9  *     notice, this list of conditions and the following disclaimer.
  10  *
  11  *  2. Redistributions in binary form must reproduce the above copyright
  12  *     notice, this list of conditions and the following disclaimer in
  13  *     the documentation and/or other materials provided with the
  14  *     distribution.
  15  *
  16  *  3. Neither the name of Lloyd Hilaiel nor the names of its
  17  *     contributors may be used to endorse or promote products derived
  18  *     from this software without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  22  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  23  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
  24  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  25  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  26  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  28  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  29  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  30  * POSSIBILITY OF SUCH DAMAGE.
  31  */
  32
  33 /*
  34  * A header only implementation of a simple stack of bytes, used in YAJL
  35  * to maintain parse state.
  36  */
  37
  38 #ifndef __YAJL_BYTESTACK_H__
  39 #define __YAJL_BYTESTACK_H__
  40
  41 #include "yajl/yajl_common.h"
  42
  43 #define YAJL_BS_INC 128
  44
  45 typedef struct yajl_bytestack_t
  46 {
  47     unsigned char * stack;
  48     unsigned int size;
  49     unsigned int used;
  50     yajl_alloc_funcs * yaf;
  51 } yajl_bytestack;
  52
  53 /* initialize a bytestack */
  54 #define yajl_bs_init(obs, _yaf) {               \
  55         (obs).stack = NULL;                     \
  56         (obs).size = 0;                         \
  57         (obs).used = 0;                         \
  58         (obs).yaf = (_yaf);                     \
  59     }                                           \
  60
  61
  62 /* initialize a bytestack */
  63 #define yajl_bs_free(obs)                 \
  64     if ((obs).stack) (obs).yaf->free((obs).yaf->ctx, (obs).stack);
  65
  66 #define yajl_bs_current(obs)               \
  67     (assert((obs).used > 0), (obs).stack[(obs).used - 1])
  68
  69 #define yajl_bs_push(obs, byte) {                       \
  70     if (((obs).size - (obs).used) == 0) {               \
  71         (obs).size += YAJL_BS_INC;                      \
  72         (obs).stack = (obs).yaf->realloc((obs).yaf->ctx,\
  73                                          (void *) (obs).stack, (obs).size);\
  74     }                                                   \
  75     (obs).stack[((obs).used)++] = (byte);               \
  76 }
  77
  78 /* removes the top item of the stack, returns nothing */
  79 #define yajl_bs_pop(obs) { ((obs).used)--; }
  80
  81 #define yajl_bs_set(obs, byte)                          \
  82     (obs).stack[((obs).used) - 1] = (byte);
  83
  84
  85 #endif