libbanshee/engine/array.c

   1 /*
   2  * Copyright (c) 2000-2001
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  */
  30
  31 #include <regions.h>
  32 #include <assert.h>
  33 #include <limits.h>
  34 #include "array.h"
  35
  36 struct array {
  37   region sameregion r;
  38   void *sameregion data;
  39   size_t elemsize;
  40   type_t elemtype;
  41   size_t nelems, nalloc;
  42 };
  43
  44 struct array *new_array(region r, size_t initialsize,
  45                         size_t typesize, type_t typeinfo)
  46 {
  47   struct array *a = ralloc(r, struct array);
  48
  49   a->r = r;
  50   a->data = typed_rarrayalloc(r, initialsize, typesize, typeinfo);
  51   a->elemsize = typesize;
  52   a->elemtype = typeinfo;
  53   a->nelems = 0;
  54   a->nalloc = initialsize;
  55
  56   return a;
  57 }
  58
  59 void *array_extend(struct array *a, int by)
  60 {
  61   size_t oldelems = a->nelems;
  62
  63   if (by < 0)
  64     assert(((unsigned int)-by) <= a->nelems && by != INT_MIN);
  65   else if (a->nelems + by > a->nalloc)
  66     {
  67       size_t newsize = a->nalloc * 2 + by;
  68       void *newdata = typed_rarrayalloc(a->r, newsize, a->elemsize, a->elemtype);
  69
  70       /* XXX: could work harder to support really large array sizes
  71          (this code will fail for a->nalloc >= (max(size_t)-by)/2) */
  72       assert(newsize > a->nalloc); /* die when we get really big */
  73       typed_rarraycopy(newdata, a->data, a->nelems, a->elemsize, a->elemtype);
  74       a->data = newdata;
  75       a->nalloc = newsize;
  76     }
  77   a->nelems += by;
  78
  79   return (char *)a->data + a->elemsize * oldelems;
  80 }
  81
  82 void array_reset(struct array *a)
  83 {
  84   a->nelems = 0;
  85 }
  86
  87 size_t array_length(struct array *a)
  88 {
  89   return a->nelems;
  90 }
  91
  92 void *array_data(struct array *a)
  93 {
  94   return a->data;
  95 }
  96