libguile/weak-vector.c

   1 /* Copyright (C) 1995, 1996, 1998, 2000, 2001, 2003, 2006, 2008, 2009,
   2  *   2010, 2011, 2012, 2013 Free Software Foundation, Inc.
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public License
   6  * as published by the Free Software Foundation; either version 3 of
   7  * the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  17  * 02110-1301 USA
  18  */
  19
  20
  21 \f
  22 #ifdef HAVE_CONFIG_H
  23 # include <config.h>
  24 #endif
  25
  26 #include <stdio.h>
  27
  28 #include "libguile/_scm.h"
  29 #include "libguile/vectors.h"
  30
  31 #include "libguile/validate.h"
  32
  33 \f
  34
  35 /* {Weak Vectors}
  36  */
  37
  38 #define VECTOR_MAX_LENGTH (SCM_T_BITS_MAX >> 8)
  39
  40 static SCM
  41 make_weak_vector (size_t len, SCM fill)
  42 #define FUNC_NAME "make-weak-vector"
  43 {
  44   SCM wv;
  45   size_t j;
  46
  47   SCM_ASSERT_RANGE (1, scm_from_size_t (len), len <= VECTOR_MAX_LENGTH);
  48
  49   if (SCM_UNBNDP (fill))
  50     fill = SCM_UNSPECIFIED;
  51
  52   wv = SCM_PACK_POINTER (scm_gc_malloc_pointerless ((len + 1) * sizeof (SCM),
  53                                            "weak vector"));
  54
  55   SCM_SET_CELL_WORD_0 (wv, (len << 8) | scm_tc7_wvect);
  56
  57   if (SCM_HEAP_OBJECT_P (fill))
  58     {
  59       memset (SCM_I_VECTOR_WELTS (wv), 0, len * sizeof (SCM));
  60       for (j = 0; j < len; j++)
  61         scm_c_weak_vector_set_x (wv, j, fill);
  62     }
  63   else
  64     for (j = 0; j < len; j++)
  65       SCM_SIMPLE_VECTOR_SET (wv, j, fill);
  66
  67   return wv;
  68 }
  69 #undef FUNC_NAME
  70
  71 SCM_DEFINE (scm_make_weak_vector, "make-weak-vector", 1, 1, 0,
  72             (SCM size, SCM fill),
  73             "Return a weak vector with @var{size} elements. If the optional\n"
  74             "argument @var{fill} is given, all entries in the vector will be\n"
  75             "set to @var{fill}. The default value for @var{fill} is the\n"
  76             "empty list.")
  77 #define FUNC_NAME s_scm_make_weak_vector
  78 {
  79   return make_weak_vector (scm_to_size_t (size), fill);
  80 }
  81 #undef FUNC_NAME
  82
  83
  84 SCM_REGISTER_PROC(s_list_to_weak_vector, "list->weak-vector", 1, 0, 0, scm_weak_vector);
  85
  86 SCM_DEFINE (scm_weak_vector, "weak-vector", 0, 0, 1,
  87            (SCM lst),
  88             "@deffnx {Scheme Procedure} list->weak-vector lst\n"
  89             "Construct a weak vector from a list: @code{weak-vector} uses\n"
  90             "the list of its arguments while @code{list->weak-vector} uses\n"
  91             "its only argument @var{l} (a list) to construct a weak vector\n"
  92             "the same way @code{list->vector} would.")
  93 #define FUNC_NAME s_scm_weak_vector
  94 {
  95   SCM wv;
  96   size_t i;
  97   long c_size;
  98
  99   SCM_VALIDATE_LIST_COPYLEN (SCM_ARG1, lst, c_size);
 100
 101   wv = make_weak_vector ((size_t) c_size, SCM_BOOL_F);
 102
 103   for (i = 0; scm_is_pair (lst); lst = SCM_CDR (lst), i++)
 104     scm_c_weak_vector_set_x (wv, i, SCM_CAR (lst));
 105
 106   return wv;
 107 }
 108 #undef FUNC_NAME
 109
 110
 111 SCM_DEFINE (scm_weak_vector_p, "weak-vector?", 1, 0, 0,
 112             (SCM obj),
 113             "Return @code{#t} if @var{obj} is a weak vector. Note that all\n"
 114             "weak hashes are also weak vectors.")
 115 #define FUNC_NAME s_scm_weak_vector_p
 116 {
 117   return scm_from_bool (SCM_I_WVECTP (obj));
 118 }
 119 #undef FUNC_NAME
 120
 121
 122 struct weak_vector_ref_data
 123 {
 124   SCM wv;
 125   size_t k;
 126 };
 127
 128 static void*
 129 weak_vector_ref (void *data)
 130 {
 131   struct weak_vector_ref_data *d = data;
 132
 133   return (void *) SCM_UNPACK (SCM_SIMPLE_VECTOR_REF (d->wv, d->k));
 134 }
 135
 136 SCM
 137 scm_c_weak_vector_ref (SCM wv, size_t k)
 138 {
 139   struct weak_vector_ref_data d;
 140   void *ret;
 141
 142   d.wv = wv;
 143   d.k = k;
 144
 145   if (k >= SCM_I_VECTOR_LENGTH (wv))
 146     scm_out_of_range (NULL, scm_from_size_t (k));
 147
 148   ret = GC_call_with_alloc_lock (weak_vector_ref, &d);
 149
 150   if (ret)
 151     return SCM_PACK_POINTER (ret);
 152   else
 153     return SCM_BOOL_F;
 154 }
 155
 156
 157 void
 158 scm_c_weak_vector_set_x (SCM wv, size_t k, SCM x)
 159 {
 160   SCM *elts;
 161   struct weak_vector_ref_data d;
 162   void *prev;
 163
 164   d.wv = wv;
 165   d.k = k;
 166
 167   if (k >= SCM_I_VECTOR_LENGTH (wv))
 168     scm_out_of_range (NULL, scm_from_size_t (k));
 169
 170   prev = GC_call_with_alloc_lock (weak_vector_ref, &d);
 171
 172   elts = SCM_I_VECTOR_WELTS (wv);
 173
 174   if (prev && SCM_HEAP_OBJECT_P (SCM_PACK_POINTER (prev)))
 175     GC_unregister_disappearing_link ((void **) &elts[k]);
 176
 177   elts[k] = x;
 178
 179   if (SCM_HEAP_OBJECT_P (x))
 180     SCM_I_REGISTER_DISAPPEARING_LINK ((void **) &elts[k],
 181                                       SCM2PTR (x));
 182 }
 183
 184
 185 \f
 186 static void
 187 scm_init_weak_vector_builtins (void)
 188 {
 189 #ifndef SCM_MAGIC_SNARFER
 190 #include "libguile/weak-vector.x"
 191 #endif
 192 }
 193
 194 void
 195 scm_init_weak_vectors ()
 196 {
 197   scm_c_register_extension ("libguile-" SCM_EFFECTIVE_VERSION,
 198                             "scm_init_weak_vector_builtins",
 199                             (scm_t_extension_init_func)scm_init_weak_vector_builtins,
 200                             NULL);
 201 }
 202
 203
 204 /*
 205   Local Variables:
 206   c-file-style: "gnu"
 207   End:
 208 */