epan/wmem/wmem_array.c

   1 /* wmem_array.c
   2  * Wireshark Memory Manager Array
   3  * Copyright 2013, Evan Huus <eapache@gmail.com>
   4  *
   5  * $Id$
   6  *
   7  * Wireshark - Network traffic analyzer
   8  * By Gerald Combs <gerald@wireshark.org>
   9  * Copyright 1998 Gerald Combs
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License along
  22  * with this program; if not, write to the Free Software Foundation, Inc.,
  23  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  24  */
  25
  26 #include "config.h"
  27
  28 #include <string.h>
  29 #include <stdlib.h>
  30 #include <glib.h>
  31
  32 #include "wmem_core.h"
  33 #include "wmem_array.h"
  34
  35 /* Holds a wmem-allocated array.
  36  *  elem_len is the size of each element
  37  *  elem_count is the number of used elements
  38  *  alloc_count is the length (in elems) of the raw buffer pointed to by buf,
  39  *      regardless of how many elems are used (the contents)
  40  */
  41 struct _wmem_array_t {
  42     wmem_allocator_t *allocator;
  43
  44     guint8 *buf;
  45
  46     gsize elem_size;
  47
  48     guint elem_count;
  49     guint alloc_count;
  50 };
  51
  52 wmem_array_t *
  53 wmem_array_sized_new(wmem_allocator_t *allocator, gsize elem_size,
  54                      guint alloc_count)
  55 {
  56     wmem_array_t *array;
  57
  58     array = wmem_new(allocator, wmem_array_t);
  59
  60     array->allocator   = allocator;
  61     array->elem_size   = elem_size;
  62     array->elem_count  = 0;
  63     array->alloc_count = alloc_count ? alloc_count : 1;
  64
  65     array->buf = (guint8 *)wmem_alloc(array->allocator,
  66             array->elem_size * array->alloc_count);
  67
  68     return array;
  69 }
  70
  71 wmem_array_t *
  72 wmem_array_new(wmem_allocator_t *allocator, const gsize elem_size)
  73 {
  74     wmem_array_t *array;
  75
  76     array = wmem_array_sized_new(allocator, elem_size, 1);
  77
  78     return array;
  79 }
  80
  81 static void
  82 wmem_array_grow(wmem_array_t *array, const guint to_add)
  83 {
  84     guint new_alloc_count, new_count;
  85
  86     new_alloc_count = array->alloc_count;
  87     new_count = array->elem_count + to_add;
  88
  89     while (new_alloc_count < new_count) {
  90         new_alloc_count *= 2;
  91     }
  92
  93     if (new_alloc_count == array->alloc_count) {
  94         return;
  95     }
  96
  97     array->buf = (guint8 *)wmem_realloc(array->allocator, array->buf,
  98             new_alloc_count * array->elem_size);
  99
 100     array->alloc_count = new_alloc_count;
 101 }
 102
 103 void
 104 wmem_array_append(wmem_array_t *array, const void *in, guint count)
 105 {
 106     wmem_array_grow(array, count);
 107
 108     memcpy(&array->buf[array->elem_count * array->elem_size], in,
 109             count * array->elem_size);
 110
 111     array->elem_count += count;
 112 }
 113
 114 void *
 115 wmem_array_index(wmem_array_t *array, guint array_index)
 116 {
 117     g_assert(array_index < array->elem_count);
 118     return &array->buf[array_index * array->elem_size];
 119 }
 120
 121 void
 122 wmem_array_sort(wmem_array_t *array, int (*compar)(const void*,const void*))
 123 {
 124     qsort(array->buf, array->elem_count, array->elem_size, compar);
 125 }
 126
 127 void *
 128 wmem_array_get_raw(wmem_array_t *array)
 129 {
 130     return array->buf;
 131 }
 132
 133 guint
 134 wmem_array_get_count(wmem_array_t *array)
 135 {
 136     return array->elem_count;
 137 }
 138
 139 /*
 140  * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
 141  *
 142  * Local variables:
 143  * c-basic-offset: 4
 144  * tab-width: 8
 145  * indent-tabs-mode: nil
 146  * End:
 147  *
 148  * vi: set shiftwidth=4 tabstop=8 expandtab:
 149  * :indentSize=4:tabSize=8:noTabs=true:
 150  */