reactos/dll/win32/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 #include "dbghelp_private.h"
  23
  24 #ifdef USE_STATS
  25 #include <math.h>
  26 #endif
  27
  28 WINE_DEFAULT_DEBUG_CHANNEL(dbghelp);
  29
  30 struct pool_arena
  31 {
  32     struct list entry;
  33     char       *current;
  34     char       *end;
  35 };
  36
  37 void pool_init(struct pool* a, size_t arena_size)
  38 {
  39     list_init( &a->arena_list );
  40     list_init( &a->arena_full );
  41     a->arena_size = arena_size;
  42 }
  43
  44 void pool_destroy(struct pool* pool)
  45 {
  46     struct pool_arena*  arena;
  47     struct pool_arena*  next;
  48
  49 #ifdef USE_STATS
  50     size_t alloc, used, num;
  51
  52     alloc = used = num = 0;
  53     LIST_FOR_EACH_ENTRY( arena, &pool->arena_list, struct pool_arena, entry )
  54     {
  55         alloc += arena->end - (char *)arena;
  56         used += arena->current - (char*)arena;
  57         num++;
  58     }
  59     LIST_FOR_EACH_ENTRY( arena, &pool->arena_full, struct pool_arena, entry )
  60     {
  61         alloc += arena->end - (char *)arena;
  62         used += arena->current - (char*)arena;
  63         num++;
  64     }
  65     if (alloc == 0) alloc = 1;      /* avoid division by zero */
  66     FIXME("STATS: pool %p has allocated %u kbytes, used %u kbytes in %u arenas, non-allocation ratio: %.2f%%\n",
  67           pool, (unsigned)(alloc >> 10), (unsigned)(used >> 10), (unsigned)num,
  68           100.0 - (float)used / (float)alloc * 100.0);
  69 #endif
  70
  71     LIST_FOR_EACH_ENTRY_SAFE( arena, next, &pool->arena_list, struct pool_arena, entry )
  72     {
  73         list_remove( &arena->entry );
  74         HeapFree(GetProcessHeap(), 0, arena);
  75     }
  76     LIST_FOR_EACH_ENTRY_SAFE( arena, next, &pool->arena_full, struct pool_arena, entry )
  77     {
  78         list_remove( &arena->entry );
  79         HeapFree(GetProcessHeap(), 0, arena);
  80     }
  81 }
  82
  83 void* pool_alloc(struct pool* pool, size_t len)
  84 {
  85     struct pool_arena*  arena;
  86     void*               ret;
  87     size_t size;
  88
  89     len = (len + 3) & ~3; /* round up size on DWORD boundary */
  90
  91     LIST_FOR_EACH_ENTRY( arena, &pool->arena_list, struct pool_arena, entry )
  92     {
  93         if (arena->end - arena->current >= len)
  94         {
  95             ret = arena->current;
  96             arena->current += len;
  97             if (arena->current + 16 >= arena->end)
  98             {
  99                 list_remove( &arena->entry );
 100                 list_add_tail( &pool->arena_full, &arena->entry );
 101             }
 102             return ret;
 103         }
 104     }
 105
 106     size = max( pool->arena_size, len );
 107     arena = HeapAlloc(GetProcessHeap(), 0, size + sizeof(struct pool_arena));
 108     if (!arena) return NULL;
 109
 110     ret = arena + 1;
 111     arena->current = (char*)ret + len;
 112     arena->end = (char*)ret + size;
 113     if (arena->current + 16 >= arena->end)
 114         list_add_tail( &pool->arena_full, &arena->entry );
 115     else
 116         list_add_head( &pool->arena_list, &arena->entry );
 117     return ret;
 118 }
 119
 120 char* pool_strdup(struct pool* pool, const char* str)
 121 {
 122     char* ret;
 123     if ((ret = pool_alloc(pool, strlen(str) + 1))) strcpy(ret, str);
 124     return ret;
 125 }
 126
 127 void vector_init(struct vector* v, unsigned esz, unsigned bucket_sz)
 128 {
 129     v->buckets = NULL;
 130     /* align size on DWORD boundaries */
 131     v->elt_size = (esz + 3) & ~3;
 132     switch (bucket_sz)
 133     {
 134     case    2: v->shift =  1; break;
 135     case    4: v->shift =  2; break;
 136     case    8: v->shift =  3; break;
 137     case   16: v->shift =  4; break;
 138     case   32: v->shift =  5; break;
 139     case   64: v->shift =  6; break;
 140     case  128: v->shift =  7; break;
 141     case  256: v->shift =  8; break;
 142     case  512: v->shift =  9; break;
 143     case 1024: v->shift = 10; break;
 144     default: assert(0);
 145     }
 146     v->num_buckets = 0;
 147     v->buckets_allocated = 0;
 148     v->num_elts = 0;
 149 }
 150
 151 unsigned vector_length(const struct vector* v)
 152 {
 153     return v->num_elts;
 154 }
 155
 156 void* vector_at(const struct vector* v, unsigned pos)
 157 {
 158     unsigned o;
 159
 160     if (pos >= v->num_elts) return NULL;
 161     o = pos & ((1 << v->shift) - 1);
 162     return (char*)v->buckets[pos >> v->shift] + o * v->elt_size;
 163 }
 164
 165 void* vector_add(struct vector* v, struct pool* pool)
 166 {
 167     unsigned    ncurr = v->num_elts++;
 168
 169     /* check that we don't wrap around */
 170     assert(v->num_elts > ncurr);
 171     if (ncurr == (v->num_buckets << v->shift))
 172     {
 173         if(v->num_buckets == v->buckets_allocated)
 174         {
 175             /* Double the bucket cache, so it scales well with big vectors.*/
 176             unsigned    new_reserved;
 177             void*       new;
 178
 179             new_reserved = 2*v->buckets_allocated;
 180             if(new_reserved == 0) new_reserved = 1;
 181
 182             /* Don't even try to resize memory.
 183                Pool datastructure is very inefficient with reallocs. */
 184             new = pool_alloc(pool, new_reserved * sizeof(void*));
 185             memcpy(new, v->buckets, v->buckets_allocated * sizeof(void*));
 186             v->buckets = new;
 187             v->buckets_allocated = new_reserved;
 188         }
 189         v->buckets[v->num_buckets] = pool_alloc(pool, v->elt_size << v->shift);
 190         return v->buckets[v->num_buckets++];
 191     }
 192     return vector_at(v, ncurr);
 193 }
 194
 195 /* We construct the sparse array as two vectors (of equal size)
 196  * The first vector (key2index) is the lookup table between the key and
 197  * an index in the second vector (elements)
 198  * When inserting an element, it's always appended in second vector (and
 199  * never moved in memory later on), only the first vector is reordered
 200  */
 201 struct key2index
 202 {
 203     unsigned long       key;
 204     unsigned            index;
 205 };
 206
 207 void sparse_array_init(struct sparse_array* sa, unsigned elt_sz, unsigned bucket_sz)
 208 {
 209     vector_init(&sa->key2index, sizeof(struct key2index), bucket_sz);
 210     vector_init(&sa->elements, elt_sz, bucket_sz);
 211 }
 212
 213 /******************************************************************
 214  *              sparse_array_lookup
 215  *
 216  * Returns the first index which key is >= at passed key
 217  */
 218 static struct key2index* sparse_array_lookup(const struct sparse_array* sa,
 219                                              unsigned long key, unsigned* idx)
 220 {
 221     struct key2index*   pk2i;
 222     unsigned            low, high;
 223
 224     if (!sa->elements.num_elts)
 225     {
 226         *idx = 0;
 227         return NULL;
 228     }
 229     high = sa->elements.num_elts;
 230     pk2i = vector_at(&sa->key2index, high - 1);
 231     if (pk2i->key < key)
 232     {
 233         *idx = high;
 234         return NULL;
 235     }
 236     if (pk2i->key == key)
 237     {
 238         *idx = high - 1;
 239         return pk2i;
 240     }
 241     low = 0;
 242     pk2i = vector_at(&sa->key2index, low);
 243     if (pk2i->key >= key)
 244     {
 245         *idx = 0;
 246         return pk2i;
 247     }
 248     /* now we have: sa(lowest key) < key < sa(highest key) */
 249     while (low < high)
 250     {
 251         *idx = (low + high) / 2;
 252         pk2i = vector_at(&sa->key2index, *idx);
 253         if (pk2i->key > key)            high = *idx;
 254         else if (pk2i->key < key)       low = *idx + 1;
 255         else                            return pk2i;
 256     }
 257     /* binary search could return exact item, we search for highest one
 258      * below the key
 259      */
 260     if (pk2i->key < key)
 261         pk2i = vector_at(&sa->key2index, ++(*idx));
 262     return pk2i;
 263 }
 264
 265 void*   sparse_array_find(const struct sparse_array* sa, unsigned long key)
 266 {
 267     unsigned            idx;
 268     struct key2index*   pk2i;
 269
 270     if ((pk2i = sparse_array_lookup(sa, key, &idx)) && pk2i->key == key)
 271         return vector_at(&sa->elements, pk2i->index);
 272     return NULL;
 273 }
 274
 275 void*   sparse_array_add(struct sparse_array* sa, unsigned long key,
 276                          struct pool* pool)
 277 {
 278     unsigned            idx, i;
 279     struct key2index*   pk2i;
 280     struct key2index*   to;
 281
 282     pk2i = sparse_array_lookup(sa, key, &idx);
 283     if (pk2i && pk2i->key == key)
 284     {
 285         FIXME("re adding an existing key\n");
 286         return NULL;
 287     }
 288     to = vector_add(&sa->key2index, pool);
 289     if (pk2i)
 290     {
 291         /* we need to shift vector's content... */
 292         /* let's do it brute force... (FIXME) */
 293         assert(sa->key2index.num_elts >= 2);
 294         for (i = sa->key2index.num_elts - 1; i > idx; i--)
 295         {
 296             pk2i = vector_at(&sa->key2index, i - 1);
 297             *to = *pk2i;
 298             to = pk2i;
 299         }
 300     }
 301
 302     to->key = key;
 303     to->index = sa->elements.num_elts;
 304
 305     return vector_add(&sa->elements, pool);
 306 }
 307
 308 unsigned sparse_array_length(const struct sparse_array* sa)
 309 {
 310     return sa->elements.num_elts;
 311 }
 312
 313 static unsigned hash_table_hash(const char* name, unsigned num_buckets)
 314 {
 315     unsigned    hash = 0;
 316     while (*name)
 317     {
 318         hash += *name++;
 319         hash += (hash << 10);
 320         hash ^= (hash >> 6);
 321     }
 322     hash += (hash << 3);
 323     hash ^= (hash >> 11);
 324     hash += (hash << 15);
 325     return hash % num_buckets;
 326 }
 327
 328 void hash_table_init(struct pool* pool, struct hash_table* ht, unsigned num_buckets)
 329 {
 330     ht->num_elts = 0;
 331     ht->num_buckets = num_buckets;
 332     ht->pool = pool;
 333     ht->buckets = NULL;
 334 }
 335
 336 void hash_table_destroy(struct hash_table* ht)
 337 {
 338 #if defined(USE_STATS)
 339     int                         i;
 340     unsigned                    len;
 341     unsigned                    min = 0xffffffff, max = 0, sq = 0;
 342     struct hash_table_elt*      elt;
 343     double                      mean, variance;
 344
 345     for (i = 0; i < ht->num_buckets; i++)
 346     {
 347         for (len = 0, elt = ht->buckets[i]; elt; elt = elt->next) len++;
 348         if (len < min) min = len;
 349         if (len > max) max = len;
 350         sq += len * len;
 351     }
 352     mean = (double)ht->num_elts / ht->num_buckets;
 353     variance = (double)sq / ht->num_buckets - mean * mean;
 354     FIXME("STATS: elts[num:%-4u size:%u mean:%f] buckets[min:%-4u variance:%+f max:%-4u]\n",
 355           ht->num_elts, ht->num_buckets, mean, min, variance, max);
 356 #if 1
 357     for (i = 0; i < ht->num_buckets; i++)
 358     {
 359         for (len = 0, elt = ht->buckets[i]; elt; elt = elt->next) len++;
 360         if (len == max)
 361         {
 362             FIXME("Longuest bucket:\n");
 363             for (elt = ht->buckets[i]; elt; elt = elt->next)
 364                 FIXME("\t%s\n", elt->name);
 365             break;
 366         }
 367
 368     }
 369 #endif
 370 #endif
 371 }
 372
 373 void hash_table_add(struct hash_table* ht, struct hash_table_elt* elt)
 374 {
 375     unsigned                    hash = hash_table_hash(elt->name, ht->num_buckets);
 376
 377     if (!ht->buckets)
 378     {
 379         ht->buckets = pool_alloc(ht->pool, ht->num_buckets * sizeof(struct hash_table_bucket));
 380         assert(ht->buckets);
 381         memset(ht->buckets, 0, ht->num_buckets * sizeof(struct hash_table_bucket));
 382     }
 383
 384     /* in some cases, we need to get back the symbols of same name in the order
 385      * in which they've been inserted. So insert new elements at the end of the list.
 386      */
 387     if (!ht->buckets[hash].first)
 388     {
 389         ht->buckets[hash].first = elt;
 390     }
 391     else
 392     {
 393         ht->buckets[hash].last->next = elt;
 394     }
 395     ht->buckets[hash].last = elt;
 396     elt->next = NULL;
 397     ht->num_elts++;
 398 }
 399
 400 void hash_table_iter_init(const struct hash_table* ht,
 401                           struct hash_table_iter* hti, const char* name)
 402 {
 403     hti->ht = ht;
 404     if (name)
 405     {
 406         hti->last = hash_table_hash(name, ht->num_buckets);
 407         hti->index = hti->last - 1;
 408     }
 409     else
 410     {
 411         hti->last = ht->num_buckets - 1;
 412         hti->index = -1;
 413     }
 414     hti->element = NULL;
 415 }
 416
 417 void* hash_table_iter_up(struct hash_table_iter* hti)
 418 {
 419     if (!hti->ht->buckets) return NULL;
 420
 421     if (hti->element) hti->element = hti->element->next;
 422     while (!hti->element && hti->index < hti->last)
 423         hti->element = hti->ht->buckets[++hti->index].first;
 424     return hti->element;
 425 }