1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/knight/shared/KeHashTable.cpp Fri Aug 15 05:22:26 2008 +0000
1.3 @@ -0,0 +1,409 @@
1.4 +#include <KeHashTable.h>
1.5 +
1.6 +using namespace Knight;
1.7 +
1.8 +struct KeHashNode
1.9 +{
1.10 + KeHashNode *next;
1.11 + uint32_t key_hash;
1.12 + const void *key;
1.13 + void *value;
1.14 +};
1.15 +
1.16 +namespace Knight
1.17 +{
1.18 + class KeHashTable
1.19 + {
1.20 + public:
1.21 + KeHashNode **buckets;
1.22 + uint32_t num_buckets;
1.23 + uint32_t shift;
1.24 + uint32_t num_entries;
1.25 + KeHashGenerator key_gen;
1.26 + KeHashMarshal key_m;
1.27 + KeHashMarshal val_m;
1.28 + ke_allocator_t *node_alloc;
1.29 + size_t key_offs;
1.30 + size_t val_offs;
1.31 + size_t node_size;
1.32 + uint32_t grow_limit;
1.33 + KeHashNode *free_list;
1.34 + bool keep_free_list;
1.35 + };
1.36 +}
1.37 +
1.38 +void *ke_DefHashMalloc(ke_allocator_t *alloc, size_t amt)
1.39 +{
1.40 + return malloc(amt);
1.41 +}
1.42 +
1.43 +void ke_DefHashFree(ke_allocator_t *alloc, void *addr)
1.44 +{
1.45 + free(addr);
1.46 +}
1.47 +
1.48 +ke_allocator_t s_DefHashAllocator =
1.49 +{
1.50 + ke_DefHashMalloc,
1.51 + ke_DefHashFree,
1.52 + NULL
1.53 +};
1.54 +
1.55 +KeHashTable *Knight::KE_CreateHashTable(
1.56 + uint32_t bits,
1.57 + KeHashGenerator key_gen,
1.58 + const KeHashMarshal *key_marshal,
1.59 + const KeHashMarshal *val_marshal,
1.60 + ke_allocator_t *nodeAlloc,
1.61 + bool keep_free_list)
1.62 +{
1.63 + KeHashTable *table;
1.64 +
1.65 + if (bits >= 27)
1.66 + {
1.67 + bits = 26;
1.68 + }
1.69 + else if (bits < 4)
1.70 + {
1.71 + bits = 4;
1.72 + }
1.73 +
1.74 + /* Validate marshals. */
1.75 + if ((key_marshal->bytes != 0
1.76 + && key_marshal->ctor == NULL)
1.77 + || (val_marshal->bytes != 0
1.78 + && val_marshal->ctor == NULL))
1.79 + {
1.80 + return NULL;
1.81 + }
1.82 +
1.83 + table = new KeHashTable;
1.84 + table->key_gen = key_gen;
1.85 + table->key_m = *key_marshal;
1.86 + table->val_m = *val_marshal;
1.87 + table->num_entries = 0;
1.88 + table->shift = bits;
1.89 + table->node_alloc = nodeAlloc == NULL ? &s_DefHashAllocator : nodeAlloc;
1.90 + table->num_buckets = (1 << bits);
1.91 + table->grow_limit = (uint32_t)(0.9f * table->num_buckets);
1.92 + table->keep_free_list = keep_free_list;
1.93 + table->free_list = NULL;
1.94 + table->buckets = (KeHashNode **)malloc(sizeof(KeHashNode *) * table->num_buckets);
1.95 + memset(table->buckets, 0, sizeof(KeHashNode *) * table->num_buckets);
1.96 +
1.97 + table->key_offs = sizeof(KeHashNode);
1.98 + if (table->key_m.bytes != 0 && table->key_m.bytes % 8 != 0)
1.99 + {
1.100 + table->key_m.bytes += 8;
1.101 + table->key_m.bytes -= (table->key_m.bytes % 8);
1.102 + }
1.103 +
1.104 + table->val_offs = table->key_offs + table->key_m.bytes;
1.105 + table->node_size = table->val_offs + table->val_m.bytes;
1.106 +
1.107 + return table;
1.108 +}
1.109 +
1.110 +#define KE_GET_BUCKET(tbl, hsh) (&(tbl)->buckets[((hsh) * 0x9E3779B9) >> (tbl)->shift])
1.111 +
1.112 +KeHashNode **ke_HashInternalFind(KeHashTable *table, uint32_t key_hash, const void *key)
1.113 +{
1.114 + KeHashNode *node;
1.115 + KeHashNode **bucket;
1.116 +
1.117 + bucket = KE_GET_BUCKET(table, key_hash);
1.118 +
1.119 + /* :TODO: move to the front once found? */
1.120 +
1.121 + while ((node = *bucket) != NULL)
1.122 + {
1.123 + if (node->key_hash == key_hash
1.124 + && ((table->key_m.cmp != NULL && table->key_m.cmp(node->key, key))
1.125 + || node->key == key))
1.126 + {
1.127 + return bucket;
1.128 + }
1.129 + bucket = &node->next;
1.130 + }
1.131 +
1.132 + return bucket;
1.133 +}
1.134 +
1.135 +void ke_ResizeHashTable(KeHashTable *table, uint32_t new_shift)
1.136 +{
1.137 + uint32_t entries;
1.138 + KeHashNode *next;
1.139 + KeHashNode *node;
1.140 + KeHashNode **rbucket;
1.141 + KeHashNode **old_buckets;
1.142 + uint32_t old_num_buckets;
1.143 +
1.144 + /* Save old data */
1.145 + old_num_buckets = table->num_buckets;
1.146 + old_buckets = table->buckets;
1.147 + entries = table->num_entries;
1.148 +
1.149 + /* Save new data */
1.150 + table->num_buckets = (1 << new_shift);
1.151 + table->shift = new_shift;
1.152 + table->grow_limit = (uint32_t)(0.9f * table->num_buckets);
1.153 +
1.154 + table->buckets = (KeHashNode **)malloc(sizeof(KeHashNode *) * table->num_buckets);
1.155 + memset(table->buckets, 0, sizeof(KeHashNode *) * table->num_buckets);
1.156 +
1.157 + /* For each old bucket... */
1.158 + for (uint32_t i = 0;
1.159 + i < old_num_buckets && entries != 0;
1.160 + i++)
1.161 + {
1.162 + node = old_buckets[i];
1.163 + /* Get each item in its list... */
1.164 + while (node != NULL)
1.165 + {
1.166 + next = node->next;
1.167 +
1.168 + /* Find the new replacement bucket it needs to go in. */
1.169 + rbucket = KE_GET_BUCKET(table, node->key_hash);
1.170 +
1.171 + /* Link this node to the next node in the new bucket. */
1.172 + if (*rbucket == NULL)
1.173 + {
1.174 + node->next = NULL;
1.175 + }
1.176 + else
1.177 + {
1.178 + node->next = *rbucket;
1.179 + }
1.180 +
1.181 + /* Add us to the front of that bucket's list. */
1.182 + *rbucket = node;
1.183 +
1.184 + node = next;
1.185 + }
1.186 + }
1.187 +
1.188 + free(old_buckets);
1.189 +}
1.190 +
1.191 +void Knight::KE_AddToHashTable(KeHashTable *table, const void *key, void *val)
1.192 +{
1.193 + KeHashNode *node;
1.194 + uint32_t key_hash;
1.195 + KeHashNode **bucket;
1.196 +
1.197 + key_hash = table->key_gen(key);
1.198 + bucket = ke_HashInternalFind(table, key_hash, key);
1.199 +
1.200 + if ((node = *bucket) != NULL)
1.201 + {
1.202 + /* Already in the table */
1.203 + if ((table->val_m.cmp != NULL && table->val_m.cmp(node->value, val))
1.204 + || node->value == val)
1.205 + {
1.206 + return;
1.207 + }
1.208 +
1.209 + /* Destroy old value if it's set. */
1.210 + if (node->value != NULL && table->val_m.dtor != NULL)
1.211 + {
1.212 + table->val_m.dtor(node->value);
1.213 + }
1.214 +
1.215 + /* Construct or set the new value. */
1.216 + if (table->val_m.bytes != 0)
1.217 + {
1.218 + table->val_m.ctor(node->value, val);
1.219 + }
1.220 + else
1.221 + {
1.222 + node->value = val;
1.223 + }
1.224 +
1.225 + return;
1.226 + }
1.227 +
1.228 + /* If we're overloaded, we may need to resize.
1.229 + * Right now, we do this if we hit a .9 entry:buckets ratio.
1.230 + */
1.231 + if (table->num_entries >= table->grow_limit)
1.232 + {
1.233 + ke_ResizeHashTable(table, table->shift << 1);
1.234 + bucket = ke_HashInternalFind(table, key_hash, key);
1.235 + }
1.236 +
1.237 + if (table->free_list != NULL)
1.238 + {
1.239 + node = table->free_list;
1.240 + table->free_list = node->next;
1.241 + }
1.242 + else
1.243 + {
1.244 + node = (KeHashNode *)table->node_alloc->alloc(table->node_alloc, table->node_size);
1.245 + }
1.246 +
1.247 + if (table->key_m.bytes == 0)
1.248 + {
1.249 + node->key = key;
1.250 + }
1.251 + else
1.252 + {
1.253 + node->key = (char *)node + table->key_offs;
1.254 + table->key_m.ctor((void *)node->key, key);
1.255 + }
1.256 +
1.257 + if (table->val_m.bytes == 0)
1.258 + {
1.259 + node->value = val;
1.260 + }
1.261 + else
1.262 + {
1.263 + node->value = (char *)node + table->val_offs;
1.264 + table->val_m.ctor(node->value, val);
1.265 + }
1.266 +
1.267 + node->next = *bucket;
1.268 + node->key_hash = key_hash;
1.269 + *bucket = node;
1.270 +}
1.271 +
1.272 +inline void ke_CleanUpHashNode(KeHashTable *table, KeHashNode *node)
1.273 +{
1.274 + /* Destroy old value if it's set. */
1.275 + if (node->value != NULL && table->val_m.dtor != NULL)
1.276 + {
1.277 + table->val_m.dtor(node->value);
1.278 + }
1.279 +
1.280 + /* Destroy the key. */
1.281 + if (table->key_m.dtor != NULL)
1.282 + {
1.283 + table->key_m.dtor(node->key);
1.284 + }
1.285 +
1.286 + /* Deallocate us as appropriate. */
1.287 + if (table->keep_free_list)
1.288 + {
1.289 + node->next = table->free_list;
1.290 + table->free_list = node;
1.291 + }
1.292 + else
1.293 + {
1.294 + table->node_alloc->dealloc(table->node_alloc, node);
1.295 + }
1.296 +}
1.297 +
1.298 +void Knight::KE_RemoveFromHashTable(KeHashTable *table, const void *key)
1.299 +{
1.300 + KeHashNode *node;
1.301 + uint32_t key_hash;
1.302 + KeHashNode **bucket;
1.303 +
1.304 + key_hash = table->key_gen(key);
1.305 + bucket = ke_HashInternalFind(table, key_hash, key);
1.306 +
1.307 + if ((node = *bucket) == NULL)
1.308 + {
1.309 + return;
1.310 + }
1.311 +
1.312 + /* Link the bucket to its next (removing us). */
1.313 + *bucket = node->next;
1.314 +
1.315 + ke_CleanUpHashNode(table, node);
1.316 +}
1.317 +
1.318 +bool Knight::KE_FindInHashTable(KeHashTable *table, const void *key, void **value)
1.319 +{
1.320 + KeHashNode *node;
1.321 + uint32_t key_hash;
1.322 + KeHashNode **bucket;
1.323 +
1.324 + key_hash = table->key_gen(key);
1.325 + bucket = ke_HashInternalFind(table, key_hash, key);
1.326 +
1.327 + if ((node = *bucket) == NULL)
1.328 + {
1.329 + return false;
1.330 + }
1.331 +
1.332 + if (value != NULL)
1.333 + {
1.334 + *value = node->value;
1.335 + }
1.336 +
1.337 + return true;
1.338 +}
1.339 +
1.340 +void Knight::KE_DestroyHashTable(KeHashTable *table)
1.341 +{
1.342 + KeHashNode *node, *next;
1.343 +
1.344 + /* Turn off this caching! */
1.345 + table->keep_free_list = false;
1.346 +
1.347 + /* Find entries in buckets that need to be freed. */
1.348 + for (uint32_t i = 0; i < table->num_buckets; i++)
1.349 + {
1.350 + node = table->buckets[i];
1.351 +
1.352 + while (node != NULL)
1.353 + {
1.354 + next = node->next;
1.355 + ke_CleanUpHashNode(table, node);
1.356 + node = next;
1.357 + }
1.358 + }
1.359 +
1.360 + /* Free the free list */
1.361 + while (table->free_list != NULL)
1.362 + {
1.363 + next = table->free_list->next;
1.364 + ke_CleanUpHashNode(table, table->free_list);
1.365 + table->free_list = next;
1.366 + }
1.367 +
1.368 + /* Destroy everything now. */
1.369 + free(table->buckets);
1.370 + delete table;
1.371 +}
1.372 +
1.373 +void Knight::KE_ClearHashTable(KeHashTable *table)
1.374 +{
1.375 + KeHashNode *node, *next;
1.376 +
1.377 + /* Free every entry in the table. */
1.378 + for (uint32_t i = 0; i < table->num_buckets; i++)
1.379 + {
1.380 + node = table->buckets[i];
1.381 +
1.382 + while (node != NULL)
1.383 + {
1.384 + next = node->next;
1.385 + ke_CleanUpHashNode(table, node);
1.386 + node = next;
1.387 + }
1.388 + }
1.389 +}
1.390 +
1.391 +#if defined _MSC_VER && (defined _M_IX86 || defined _M_AMD64 || defined _M_X64)
1.392 +#pragma intrinsic(_rotl)
1.393 +#endif
1.394 +
1.395 +uint32_t Knight::KE_HashString(const void *str)
1.396 +{
1.397 + uint32_t h;
1.398 + const unsigned char *us;
1.399 +
1.400 + h = 0;
1.401 +
1.402 + for (us = (const unsigned char *)str; *us != 0; us++)
1.403 + {
1.404 +#if defined _MSC_VER && (defined _M_IX86 || defined _M_AMD64 || defined _M_X64)
1.405 + h = _rotl(h, 4) ^ *us;
1.406 +#else
1.407 + h = ((h << 4) | (h >> 28)) ^ *us;
1.408 +#endif
1.409 + }
1.410 +
1.411 + return h;
1.412 +}
