Dogcows Code - chaz/yoink/blob - src/Moof/yajl/src/yajl_buf.c

   1 /*
   2  * Copyright 2007-2009, 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 #include "yajl_buf.h"
  34
  35 #include <assert.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38
  39 #define YAJL_BUF_INIT_SIZE 2048
  40
  41 struct yajl_buf_t {
  42     unsigned int len;
  43     unsigned int used;
  44     unsigned char * data;
  45     yajl_alloc_funcs * alloc;
  46 };
  47
  48 static
  49 void yajl_buf_ensure_available(yajl_buf buf, unsigned int want)
  50 {
  51     unsigned int need;
  52
  53     assert(buf != NULL);
  54
  55     /* first call */
  56     if (buf->data == NULL) {
  57         buf->len = YAJL_BUF_INIT_SIZE;
  58         buf->data = (unsigned char *) YA_MALLOC(buf->alloc, buf->len);
  59         buf->data[0] = 0;
  60     }
  61
  62     need = buf->len;
  63
  64     while (want >= (need - buf->used)) need <<= 1;
  65
  66     if (need != buf->len) {
  67         buf->data = (unsigned char *) YA_REALLOC(buf->alloc, buf->data, need);
  68         buf->len = need;
  69     }
  70 }
  71
  72 yajl_buf yajl_buf_alloc(yajl_alloc_funcs * alloc)
  73 {
  74     yajl_buf b = YA_MALLOC(alloc, sizeof(struct yajl_buf_t));
  75     memset((void *) b, 0, sizeof(struct yajl_buf_t));
  76     b->alloc = alloc;
  77     return b;
  78 }
  79
  80 void yajl_buf_free(yajl_buf buf)
  81 {
  82     assert(buf != NULL);
  83     if (buf->data) YA_FREE(buf->alloc, buf->data);
  84     YA_FREE(buf->alloc, buf);
  85 }
  86
  87 void yajl_buf_append(yajl_buf buf, const void * data, unsigned int len)
  88 {
  89     yajl_buf_ensure_available(buf, len);
  90     if (len > 0) {
  91         assert(data != NULL);
  92         memcpy(buf->data + buf->used, data, len);
  93         buf->used += len;
  94         buf->data[buf->used] = 0;
  95     }
  96 }
  97
  98 void yajl_buf_clear(yajl_buf buf)
  99 {
 100     buf->used = 0;
 101     if (buf->data) buf->data[buf->used] = 0;
 102 }
 103
 104 const unsigned char * yajl_buf_data(yajl_buf buf)
 105 {
 106     return buf->data;
 107 }
 108
 109 unsigned int yajl_buf_len(yajl_buf buf)
 110 {
 111     return buf->used;
 112 }
 113
 114 void
 115 yajl_buf_truncate(yajl_buf buf, unsigned int len)
 116 {
 117     assert(len <= buf->used);
 118     buf->used = len;
 119 }