src/gallium/auxiliary/util/u_dynarray.h

   1 /**************************************************************************
   2  *
   3  * Copyright 2010 Luca Barbieri
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining
   6  * a copy of this software and associated documentation files (the
   7  * "Software"), to deal in the Software without restriction, including
   8  * without limitation the rights to use, copy, modify, merge, publish,
   9  * distribute, sublicense, and/or sell copies of the Software, and to
  10  * permit persons to whom the Software is furnished to do so, subject to
  11  * the following conditions:
  12  *
  13  * The above copyright notice and this permission notice (including the
  14  * next paragraph) shall be included in all copies or substantial
  15  * portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  18  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  19  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  20  * IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
  21  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  22  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  23  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  24  *
  25  **************************************************************************/
  26
  27 #ifndef U_DYNARRAY_H
  28 #define U_DYNARRAY_H
  29
  30 #include "pipe/p_compiler.h"
  31 #include "util/u_memory.h"
  32
  33 /* A zero-initialized version of this is guaranteed to represent an
  34  * empty array.
  35  *
  36  * Also, size <= capacity and data != 0 if and only if capacity != 0
  37  * capacity will always be the allocation size of data
  38  */
  39 struct util_dynarray
  40 {
  41    void *data;
  42    unsigned size;
  43    unsigned capacity;
  44 };
  45
  46 static INLINE void
  47 util_dynarray_init(struct util_dynarray *buf)
  48 {
  49    memset(buf, 0, sizeof(*buf));
  50 }
  51
  52 static INLINE void
  53 util_dynarray_fini(struct util_dynarray *buf)
  54 {
  55    if(buf->data)
  56    {
  57       FREE(buf->data);
  58       util_dynarray_init(buf);
  59    }
  60 }
  61
  62 /* use util_dynarray_trim to reduce the allocated storage */
  63 static INLINE void *
  64 util_dynarray_resize(struct util_dynarray *buf, unsigned newsize)
  65 {
  66    char *p;
  67    if(newsize > buf->capacity)
  68    {
  69       unsigned newcap = buf->capacity << 1;
  70       if(newsize > newcap)
  71               newcap = newsize;
  72       buf->data = REALLOC(buf->data, buf->capacity, newcap);
  73       buf->capacity = newcap;
  74    }
  75
  76    p = (char *)buf->data + buf->size;
  77    buf->size = newsize;
  78    return p;
  79 }
  80
  81 static INLINE void *
  82 util_dynarray_grow(struct util_dynarray *buf, int diff)
  83 {
  84    return util_dynarray_resize(buf, buf->size + diff);
  85 }
  86
  87 static INLINE void
  88 util_dynarray_trim(struct util_dynarray *buf)
  89 {
  90    if (buf->size != buf->capacity) {
  91       if (buf->size) {
  92          buf->data = REALLOC(buf->data, buf->capacity, buf->size);
  93          buf->capacity = buf->size;
  94       }
  95       else {
  96          FREE(buf->data);
  97          buf->data = 0;
  98          buf->capacity = 0;
  99       }
 100    }
 101 }
 102
 103 #define util_dynarray_append(buf, type, v) do {type __v = (v); memcpy(util_dynarray_grow((buf), sizeof(type)), &__v, sizeof(type));} while(0)
 104 #define util_dynarray_top_ptr(buf, type) (type*)((char*)(buf)->data + (buf)->size - sizeof(type))
 105 #define util_dynarray_top(buf, type) *util_dynarray_top_ptr(buf, type)
 106 #define util_dynarray_pop_ptr(buf, type) (type*)((char*)(buf)->data + ((buf)->size -= sizeof(type)))
 107 #define util_dynarray_pop(buf, type) *util_dynarray_pop_ptr(buf, type)
 108 #define util_dynarray_contains(buf, type) ((buf)->size >= sizeof(type))
 109
 110 #endif /* U_DYNARRAY_H */
 111