dlls/dbghelp/storage.c

   1 /*
   2  * Various storage structures (pool allocation, vector, hash table)
   3  *
   4  * Copyright (C) 1993, Eric Youngdale.
   5  *               2004, Eric Pouech
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  20  */
  21
  22
  23 #include <assert.h>
  24 #include <stdlib.h>
  25 #include "wine/debug.h"
  26
  27 #include "dbghelp_private.h"
  28
  29 WINE_DEFAULT_DEBUG_CHANNEL(dbghelp);
  30
  31 void pool_init(struct pool* pool, size_t arena_size)
  32 {
  33     pool->heap = HeapCreate(HEAP_NO_SERIALIZE, arena_size, 0);
  34 }
  35
  36 void pool_destroy(struct pool* pool)
  37 {
  38     HeapDestroy(pool->heap);
  39 }
  40
  41 void* pool_alloc(struct pool* pool, size_t len)
  42 {
  43     return HeapAlloc(pool->heap, 0, len);
  44 }
  45
  46 void* pool_realloc(struct pool* pool, void* ptr, size_t len)
  47 {
  48     return ptr ? HeapReAlloc(pool->heap, 0, ptr, len) : pool_alloc(pool, len);
  49 }
  50
  51 char* pool_strdup(struct pool* pool, const char* str)
  52 {
  53     char* ret;
  54     if ((ret = pool_alloc(pool, strlen(str) + 1))) strcpy(ret, str);
  55     return ret;
  56 }
  57
  58 void vector_init(struct vector* v, unsigned esz, unsigned bucket_sz)
  59 {
  60     v->buckets = NULL;
  61     /* align size on DWORD boundaries */
  62     v->elt_size = (esz + 3) & ~3;
  63     switch (bucket_sz)
  64     {
  65     case    2: v->shift =  1; break;
  66     case    4: v->shift =  2; break;
  67     case    8: v->shift =  3; break;
  68     case   16: v->shift =  4; break;
  69     case   32: v->shift =  5; break;
  70     case   64: v->shift =  6; break;
  71     case  128: v->shift =  7; break;
  72     case  256: v->shift =  8; break;
  73     case  512: v->shift =  9; break;
  74     case 1024: v->shift = 10; break;
  75     default: assert(0);
  76     }
  77     v->num_buckets = 0;
  78     v->buckets_allocated = 0;
  79     v->num_elts = 0;
  80 }
  81
  82 unsigned vector_length(const struct vector* v)
  83 {
  84     return v->num_elts;
  85 }
  86
  87 void* vector_at(const struct vector* v, unsigned pos)
  88 {
  89     unsigned o;
  90
  91     if (pos >= v->num_elts) return NULL;
  92     o = pos & ((1 << v->shift) - 1);
  93     return (char*)v->buckets[pos >> v->shift] + o * v->elt_size;
  94 }
  95
  96 void* vector_add(struct vector* v, struct pool* pool)
  97 {
  98     if (v->num_elts == (v->num_buckets << v->shift))
  99     {
 100         if (v->num_buckets == v->buckets_allocated)
 101         {
 102             /* Double the bucket cache, so it scales well with big vectors.*/
 103             unsigned    new_reserved = v->buckets_allocated ? v->buckets_allocated * 2 : 1;
 104             void*       new;
 105
 106             new = pool_realloc(pool, v->buckets, new_reserved * sizeof(void*));
 107             if (!new) return NULL;
 108             v->buckets = new;
 109             v->buckets_allocated = new_reserved;
 110         }
 111         v->buckets[v->num_buckets] = pool_alloc(pool, v->elt_size << v->shift);
 112         if (!v->buckets[v->num_buckets]) return NULL;
 113         v->num_elts++;
 114         return v->buckets[v->num_buckets++];
 115     }
 116     return vector_at(v, v->num_elts++);
 117 }
 118
 119 /* We construct the sparse array as two vectors (of equal size)
 120  * The first vector (key2index) is the lookup table between the key and
 121  * an index in the second vector (elements)
 122  * When inserting an element, it's always appended in second vector (and
 123  * never moved in memory later on), only the first vector is reordered
 124  */
 125 struct key2index
 126 {
 127     ULONG_PTR           key;
 128     unsigned            index;
 129 };
 130
 131 void sparse_array_init(struct sparse_array* sa, unsigned elt_sz, unsigned bucket_sz)
 132 {
 133     vector_init(&sa->key2index, sizeof(struct key2index), bucket_sz);
 134     vector_init(&sa->elements, elt_sz, bucket_sz);
 135 }
 136
 137 /******************************************************************
 138  *              sparse_array_lookup
 139  *
 140  * Returns the first index which key is >= at passed key
 141  */
 142 static struct key2index* sparse_array_lookup(const struct sparse_array* sa,
 143                                              ULONG_PTR key, unsigned* idx)
 144 {
 145     struct key2index*   pk2i;
 146     unsigned            low, high;
 147
 148     if (!sa->elements.num_elts)
 149     {
 150         *idx = 0;
 151         return NULL;
 152     }
 153     high = sa->elements.num_elts;
 154     pk2i = vector_at(&sa->key2index, high - 1);
 155     if (pk2i->key < key)
 156     {
 157         *idx = high;
 158         return NULL;
 159     }
 160     if (pk2i->key == key)
 161     {
 162         *idx = high - 1;
 163         return pk2i;
 164     }
 165     low = 0;
 166     pk2i = vector_at(&sa->key2index, low);
 167     if (pk2i->key >= key)
 168     {
 169         *idx = 0;
 170         return pk2i;
 171     }
 172     /* now we have: sa(lowest key) < key < sa(highest key) */
 173     while (low < high)
 174     {
 175         *idx = (low + high) / 2;
 176         pk2i = vector_at(&sa->key2index, *idx);
 177         if (pk2i->key > key)            high = *idx;
 178         else if (pk2i->key < key)       low = *idx + 1;
 179         else                            return pk2i;
 180     }
 181     /* binary search could return exact item, we search for highest one
 182      * below the key
 183      */
 184     if (pk2i->key < key)
 185         pk2i = vector_at(&sa->key2index, ++(*idx));
 186     return pk2i;
 187 }
 188
 189 void*   sparse_array_find(const struct sparse_array* sa, ULONG_PTR key)
 190 {
 191     unsigned            idx;
 192     struct key2index*   pk2i;
 193
 194     if ((pk2i = sparse_array_lookup(sa, key, &idx)) && pk2i->key == key)
 195         return vector_at(&sa->elements, pk2i->index);
 196     return NULL;
 197 }
 198
 199 void*   sparse_array_add(struct sparse_array* sa, ULONG_PTR key,
 200                          struct pool* pool)
 201 {
 202     unsigned            idx, i;
 203     struct key2index*   pk2i;
 204     struct key2index*   to;
 205
 206     pk2i = sparse_array_lookup(sa, key, &idx);
 207     if (pk2i && pk2i->key == key)
 208     {
 209         FIXME("re-adding an existing key\n");
 210         return NULL;
 211     }
 212     to = vector_add(&sa->key2index, pool);
 213     if (pk2i)
 214     {
 215         /* we need to shift vector's content... */
 216         /* let's do it brute force... (FIXME) */
 217         assert(sa->key2index.num_elts >= 2);
 218         for (i = sa->key2index.num_elts - 1; i > idx; i--)
 219         {
 220             pk2i = vector_at(&sa->key2index, i - 1);
 221             *to = *pk2i;
 222             to = pk2i;
 223         }
 224     }
 225
 226     to->key = key;
 227     to->index = sa->elements.num_elts;
 228
 229     return vector_add(&sa->elements, pool);
 230 }
 231
 232 unsigned sparse_array_length(const struct sparse_array* sa)
 233 {
 234     return sa->elements.num_elts;
 235 }
 236
 237 static unsigned hash_table_hash(const char* name, unsigned num_buckets)
 238 {
 239     unsigned    hash = 0;
 240     while (*name)
 241     {
 242         hash += *name++;
 243         hash += (hash << 10);
 244         hash ^= (hash >> 6);
 245     }
 246     hash += (hash << 3);
 247     hash ^= (hash >> 11);
 248     hash += (hash << 15);
 249     return hash % num_buckets;
 250 }
 251
 252 void hash_table_init(struct pool* pool, struct hash_table* ht, unsigned num_buckets)
 253 {
 254     ht->num_elts = 0;
 255     ht->num_buckets = num_buckets;
 256     ht->pool = pool;
 257     ht->buckets = NULL;
 258 }
 259
 260 void hash_table_destroy(struct hash_table* ht)
 261 {
 262 #if defined(USE_STATS)
 263     int                         i;
 264     unsigned                    len;
 265     unsigned                    min = 0xffffffff, max = 0, sq = 0;
 266     struct hash_table_elt*      elt;
 267     double                      mean, variance;
 268
 269     for (i = 0; i < ht->num_buckets; i++)
 270     {
 271         for (len = 0, elt = ht->buckets[i]; elt; elt = elt->next) len++;
 272         if (len < min) min = len;
 273         if (len > max) max = len;
 274         sq += len * len;
 275     }
 276     mean = (double)ht->num_elts / ht->num_buckets;
 277     variance = (double)sq / ht->num_buckets - mean * mean;
 278     FIXME("STATS: elts[num:%-4u size:%u mean:%f] buckets[min:%-4u variance:%+f max:%-4u]\n",
 279           ht->num_elts, ht->num_buckets, mean, min, variance, max);
 280
 281     for (i = 0; i < ht->num_buckets; i++)
 282     {
 283         for (len = 0, elt = ht->buckets[i]; elt; elt = elt->next) len++;
 284         if (len == max)
 285         {
 286             FIXME("Longest bucket:\n");
 287             for (elt = ht->buckets[i]; elt; elt = elt->next)
 288                 FIXME("\t%s\n", elt->name);
 289             break;
 290         }
 291
 292     }
 293 #endif
 294 }
 295
 296 void hash_table_add(struct hash_table* ht, struct hash_table_elt* elt)
 297 {
 298     unsigned                    hash = hash_table_hash(elt->name, ht->num_buckets);
 299
 300     if (!ht->buckets)
 301     {
 302         ht->buckets = pool_alloc(ht->pool, ht->num_buckets * sizeof(struct hash_table_bucket));
 303         assert(ht->buckets);
 304         memset(ht->buckets, 0, ht->num_buckets * sizeof(struct hash_table_bucket));
 305     }
 306
 307     /* in some cases, we need to get back the symbols of same name in the order
 308      * in which they've been inserted. So insert new elements at the end of the list.
 309      */
 310     if (!ht->buckets[hash].first)
 311     {
 312         ht->buckets[hash].first = elt;
 313     }
 314     else
 315     {
 316         ht->buckets[hash].last->next = elt;
 317     }
 318     ht->buckets[hash].last = elt;
 319     elt->next = NULL;
 320     ht->num_elts++;
 321 }
 322
 323 void hash_table_iter_init(const struct hash_table* ht,
 324                           struct hash_table_iter* hti, const char* name)
 325 {
 326     hti->ht = ht;
 327     if (name)
 328     {
 329         hti->last = hash_table_hash(name, ht->num_buckets);
 330         hti->index = hti->last - 1;
 331     }
 332     else
 333     {
 334         hti->last = ht->num_buckets - 1;
 335         hti->index = -1;
 336     }
 337     hti->element = NULL;
 338 }
 339
 340 void* hash_table_iter_up(struct hash_table_iter* hti)
 341 {
 342     if (!hti->ht->buckets) return NULL;
 343
 344     if (hti->element) hti->element = hti->element->next;
 345     while (!hti->element && hti->index < hti->last)
 346         hti->element = hti->ht->buckets[++hti->index].first;
 347     return hti->element;
 348 }