sys/libprop/prop_stack.c

   1 /* $NetBSD: prop_stack.c,v 1.2 2007/08/30 12:23:54 joerg Exp $ */
   2
   3 /*-
   4  * Copyright (c) 2007 Joerg Sonnenberger <joerg@NetBSD.org>.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  21  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  22  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  23  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  24  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  25  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  26  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  27  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  28  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include "prop_stack.h"
  33 #include "prop_object_impl.h"
  34
  35 void
  36 _prop_stack_init(prop_stack_t stack)
  37 {
  38         stack->used_intern_elems = 0;
  39         SLIST_INIT(&stack->extern_elems);
  40 }
  41
  42 bool
  43 _prop_stack_push(prop_stack_t stack, prop_object_t obj, void *data1,
  44     void *data2, void *data3)
  45 {
  46         struct _prop_stack_extern_elem *eelem;
  47         struct _prop_stack_intern_elem *ielem;
  48
  49         if (stack->used_intern_elems == PROP_STACK_INTERN_ELEMS) {
  50                 eelem = _PROP_MALLOC(sizeof(*eelem), M_TEMP);
  51
  52                 if (eelem == NULL)
  53                         return false;
  54
  55                 eelem->object = obj;
  56                 eelem->object_data[0] = data1;
  57                 eelem->object_data[1] = data2;
  58                 eelem->object_data[2] = data3;
  59
  60                 SLIST_INSERT_HEAD(&stack->extern_elems, eelem, stack_link);
  61
  62                 return true;
  63         }
  64
  65         _PROP_ASSERT(stack->used_intern_elems < PROP_STACK_INTERN_ELEMS);
  66         _PROP_ASSERT(SLIST_EMPTY(&stack->extern_elems));
  67
  68         ielem = &stack->intern_elems[stack->used_intern_elems];
  69         ielem->object = obj;
  70         ielem->object_data[0] = data1;
  71         ielem->object_data[1] = data2;
  72         ielem->object_data[2] = data3;
  73
  74         ++stack->used_intern_elems;
  75
  76         return true;
  77 }
  78
  79 bool
  80 _prop_stack_pop(prop_stack_t stack, prop_object_t *obj, void **data1,
  81     void **data2, void **data3)
  82 {
  83         struct _prop_stack_extern_elem *eelem;
  84         struct _prop_stack_intern_elem *ielem;
  85
  86         if (stack->used_intern_elems == 0)
  87                 return false;
  88
  89         if ((eelem = SLIST_FIRST(&stack->extern_elems)) != NULL) {
  90                 _PROP_ASSERT(stack->used_intern_elems == PROP_STACK_INTERN_ELEMS);
  91
  92                 SLIST_REMOVE_HEAD(&stack->extern_elems, stack_link);
  93                 if (obj)
  94                         *obj = eelem->object;
  95                 if (data1)
  96                         *data1 = eelem->object_data[0];
  97                 if (data2)
  98                         *data2 = eelem->object_data[1];
  99                 if (data3)
 100                         *data3 = eelem->object_data[2];
 101                 _PROP_FREE(eelem, M_TEMP);
 102                 return true;
 103         }
 104
 105         --stack->used_intern_elems;
 106         ielem = &stack->intern_elems[stack->used_intern_elems];
 107
 108         if (obj)
 109                 *obj = ielem->object;
 110         if (data1)
 111                 *data1 = ielem->object_data[0];
 112         if (data2)
 113                 *data2 = ielem->object_data[1];
 114         if (data3)
 115                 *data3 = ielem->object_data[2];
 116
 117         return true;
 118 }