Shad Ansari | 2f7f9be | 2017-06-07 13:34:53 -0700 | [diff] [blame^] | 1 | /* |
| 2 | <:copyright-BRCM:2016:DUAL/GPL:standard |
| 3 | |
| 4 | Broadcom Proprietary and Confidential.(c) 2016 Broadcom |
| 5 | All Rights Reserved |
| 6 | |
| 7 | Unless you and Broadcom execute a separate written software license |
| 8 | agreement governing use of this software, this software is licensed |
| 9 | to you under the terms of the GNU General Public License version 2 |
| 10 | (the "GPL"), available at http://www.broadcom.com/licenses/GPLv2.php, |
| 11 | with the following added to such license: |
| 12 | |
| 13 | As a special exception, the copyright holders of this software give |
| 14 | you permission to link this software with independent modules, and |
| 15 | to copy and distribute the resulting executable under terms of your |
| 16 | choice, provided that you also meet, for each linked independent |
| 17 | module, the terms and conditions of the license of that module. |
| 18 | An independent module is a module which is not derived from this |
| 19 | software. The special exception does not apply to any modifications |
| 20 | of the software. |
| 21 | |
| 22 | Not withstanding the above, under no circumstances may you combine |
| 23 | this software in any way with any other Broadcom software provided |
| 24 | under a license other than the GPL, without Broadcom's express prior |
| 25 | written consent. |
| 26 | |
| 27 | :> |
| 28 | */ |
| 29 | #include "bcmos_hash_table.h" |
| 30 | |
| 31 | #define ht_overhead sizeof(void *) |
| 32 | |
| 33 | /** Create a hash table using a block pool |
| 34 | * \param[in] pool_parm pointer to block pool parameters |
| 35 | * \param[in] max_data_entries Maximum entries the hash table needs to hold |
| 36 | * \param[in] entry_size Size of each entry in bytes |
| 37 | * \param[in] key_size Size of each key in bytes |
| 38 | * \return pointer to newly created hash table |
| 39 | */ |
| 40 | static hash_table *hash_table_create_in_pool(bcmos_blk_pool_parm *pool_parm, |
| 41 | uint32_t max_data_entries, |
| 42 | uint16_t entry_size, |
| 43 | uint8_t key_size) |
| 44 | { |
| 45 | uint32_t lookup_table_entries = max_data_entries + (max_data_entries / 4); |
| 46 | hash_table *ht; |
| 47 | bcmos_errno err; |
| 48 | |
| 49 | if (pool_parm == NULL) |
| 50 | { |
| 51 | BUG(); |
| 52 | return NULL; |
| 53 | } |
| 54 | |
| 55 | entry_size += key_size; |
| 56 | |
| 57 | ht = bcmos_alloc(sizeof(hash_table)); |
| 58 | if (ht == NULL) |
| 59 | { |
| 60 | BUG(); |
| 61 | return NULL; |
| 62 | } |
| 63 | |
| 64 | ht->obj_len = entry_size; |
| 65 | ht->key_len = key_size; |
| 66 | ht->data_offset = ht_overhead; |
| 67 | ht->ht_lookup_tbl_entries = lookup_table_entries; |
| 68 | ht->ht_max_data_entries = max_data_entries; |
| 69 | ht->look_up_entries_tbl = bcmos_alloc(lookup_table_entries * sizeof(ht_block)); |
| 70 | |
| 71 | if (ht->look_up_entries_tbl == NULL) |
| 72 | { |
| 73 | bcmos_free(ht); |
| 74 | BUG(); |
| 75 | return NULL; |
| 76 | } |
| 77 | |
| 78 | ht->ht_cur_entries = 0; |
| 79 | err = bcmos_blk_pool_create(&ht->key_data_pool, pool_parm); |
| 80 | |
| 81 | if (err != BCM_ERR_OK) |
| 82 | { |
| 83 | bcmos_free(ht->look_up_entries_tbl); |
| 84 | bcmos_free(ht); |
| 85 | BUG(); |
| 86 | return NULL; |
| 87 | } |
| 88 | |
| 89 | if (ht->ht_max_data_entries > ht->ht_lookup_tbl_entries) |
| 90 | { |
| 91 | BUG(); |
| 92 | } |
| 93 | |
| 94 | ht->obj_len -= ht->key_len; |
| 95 | |
| 96 | memset(ht->look_up_entries_tbl, 0, lookup_table_entries * sizeof(ht_block)); |
| 97 | return ht; |
| 98 | } |
| 99 | |
| 100 | hash_table *hash_table_create(uint32_t max_data_entries, |
| 101 | uint16_t entry_size, |
| 102 | uint8_t key_size, |
| 103 | char *pool_name) |
| 104 | { |
| 105 | bcmos_blk_pool_parm parm = {0}; |
| 106 | |
| 107 | parm.name = pool_name; |
| 108 | parm.blk_size = entry_size + key_size + ht_overhead; |
| 109 | parm.num_blks = max_data_entries; |
| 110 | |
| 111 | return hash_table_create_in_pool(&parm, max_data_entries, entry_size, key_size); |
| 112 | } |
| 113 | |
| 114 | /** Hash a length of bytes into a uint32_t |
| 115 | * \param[in] key Bytes to hash |
| 116 | * \param[in] len Number of bytes in key |
| 117 | * \return The hash as a uint32_t |
| 118 | */ |
| 119 | static uint32_t get_hash_for_key(const uint8_t *key, uint8_t len) |
| 120 | { |
| 121 | uint32_t hash = 5381; |
| 122 | uint8_t i; |
| 123 | const uint8_t *tmp = key; |
| 124 | for (i = 0; i < len; tmp++, i++) |
| 125 | { |
| 126 | hash = ((hash << 5) + hash) + (*tmp); |
| 127 | } |
| 128 | |
| 129 | return hash; |
| 130 | } |
| 131 | |
| 132 | /** Gets a hash key used for the keyDataPool in the HashTable |
| 133 | * \param[in] ht Associated hashtable we are getting hash for key for |
| 134 | * \param[in] key Key we are getting hash for |
| 135 | * \return An index into the keyDataPool |
| 136 | */ |
| 137 | static uint32_t get_hash_val_for_key(const hash_table *ht, const uint8_t *key) |
| 138 | { |
| 139 | return get_hash_for_key(key, ht->key_len) % ht->ht_lookup_tbl_entries; |
| 140 | } |
| 141 | |
| 142 | /** Returns the location of the key within an HtBlock |
| 143 | * \param[in] ht Hash table in question |
| 144 | * \param[in] block HtBlock in question |
| 145 | * \return pointer to the data within the block |
| 146 | */ |
| 147 | static uint8_t *get_key_from_block_in_table(const hash_table *ht, ht_block *block) |
| 148 | { |
| 149 | return(uint8_t *) block + ht->data_offset + ht->obj_len; |
| 150 | } |
| 151 | |
| 152 | /** Gets and populates a HtBlock with all of its data |
| 153 | * \param[in] next Next block in this buckets chain |
| 154 | * \param[in] ht Hash table in question |
| 155 | * \param[in] key This blocks key |
| 156 | * \param[in] val This blocks data |
| 157 | * \return The block that we allocated and returned |
| 158 | */ |
| 159 | static ht_block *fill_ht_block(ht_block *next, |
| 160 | hash_table *ht, |
| 161 | const uint8_t *key, |
| 162 | const void *val) |
| 163 | { |
| 164 | ht_block *dest_block = bcmos_blk_pool_alloc(&ht->key_data_pool); |
| 165 | |
| 166 | if (dest_block != NULL) |
| 167 | { |
| 168 | /* storage is nextobj ptr, hash obj, |
| 169 | key which keeps all uint32_t aligned. */ |
| 170 | dest_block->next_chain = next; |
| 171 | |
| 172 | if (val != NULL) |
| 173 | { |
| 174 | memcpy((uint8_t *) dest_block + ht->data_offset, val, ht->obj_len); |
| 175 | } |
| 176 | else |
| 177 | { |
| 178 | memset((uint8_t *) dest_block + ht->data_offset,0,ht->obj_len); |
| 179 | } |
| 180 | |
| 181 | /* Need to put key in after obj */ |
| 182 | memcpy( |
| 183 | (uint8_t *) dest_block + ht->data_offset + ht->obj_len, |
| 184 | key, |
| 185 | ht->key_len); |
| 186 | } |
| 187 | |
| 188 | return dest_block; |
| 189 | } |
| 190 | |
| 191 | /** Determine whether two keys in a particular hash table match |
| 192 | * \param[in] ht Hashtable |
| 193 | * \param[in] key_a first key to compare |
| 194 | * \param[in] key_b second key to compare |
| 195 | * \return whether they are the same |
| 196 | */ |
| 197 | static bcmos_bool is_key_match(const hash_table *ht, const uint8_t *key_a, const uint8_t *key_b) |
| 198 | { |
| 199 | return memcmp(key_a, key_b, ht->key_len) == 0; |
| 200 | } |
| 201 | |
| 202 | /** Searches a chained bucket looking for an instance of the key. If found returns the block if found the key in. |
| 203 | * Prev guy is set to the block in the chain before the block we returned (except in the case * where there is no |
| 204 | * block before the one we returned. |
| 205 | * \param[in] ht HashTable in question |
| 206 | * \param[in] key_to_find Key we wonder if exists |
| 207 | * \param[in] chain_start Where to start looking in the chain |
| 208 | * \param[in] prev_block The previous guy before the block we returned (if exists) |
| 209 | * \return The block that matches doesExists (if exists) |
| 210 | */ |
| 211 | static ht_block *get_key_loc_in_chain( |
| 212 | const hash_table *ht, |
| 213 | const uint8_t *key_to_find, |
| 214 | ht_block *chain_start, |
| 215 | ht_block **prev_block) |
| 216 | { |
| 217 | *prev_block = NULL; |
| 218 | while (chain_start != NULL) |
| 219 | { |
| 220 | if (is_key_match(ht, key_to_find, get_key_from_block_in_table(ht, chain_start))) |
| 221 | { |
| 222 | return chain_start; |
| 223 | } |
| 224 | *prev_block = chain_start; |
| 225 | chain_start = chain_start->next_chain; |
| 226 | } |
| 227 | return NULL; |
| 228 | } |
| 229 | |
| 230 | bcmos_bool hash_table_remove(hash_table *ht, const uint8_t *key) |
| 231 | { |
| 232 | uint32_t hash_val = get_hash_val_for_key(ht, key); |
| 233 | ht_block *prev_entry; |
| 234 | ht_block *entry = get_key_loc_in_chain( |
| 235 | ht, |
| 236 | key, |
| 237 | ht->look_up_entries_tbl[hash_val].next_chain, |
| 238 | &prev_entry); |
| 239 | |
| 240 | if (entry == NULL) |
| 241 | { |
| 242 | /* No one to delete */ |
| 243 | return BCMOS_FALSE; |
| 244 | } |
| 245 | else |
| 246 | { |
| 247 | ht->ht_cur_entries--; |
| 248 | if (prev_entry == NULL) |
| 249 | { |
| 250 | /* last entry */ |
| 251 | ht->look_up_entries_tbl[hash_val].next_chain = entry->next_chain; |
| 252 | } |
| 253 | else |
| 254 | { |
| 255 | prev_entry->next_chain = entry->next_chain; |
| 256 | } |
| 257 | bcmos_blk_pool_free(entry); |
| 258 | return BCMOS_TRUE; |
| 259 | } |
| 260 | } |
| 261 | |
| 262 | /** Returns a pointer to the data within the HT |
| 263 | * \param[in] ht Hashtable in question |
| 264 | * \param[in] block_ptr HtBlock that we wonder where its data is |
| 265 | */ |
| 266 | static void *get_ht_data_ptr(const hash_table *ht, ht_block *block_ptr) |
| 267 | { |
| 268 | return(uint8_t*)block_ptr + ht->data_offset; |
| 269 | } |
| 270 | |
| 271 | |
| 272 | /** Get an entry in the hash table |
| 273 | * \param[in] ht pointer to hash table |
| 274 | * \param[in] key pointer to key data |
| 275 | * \param[in] hash_val hash value of key |
| 276 | * \return pointer to hash table entry |
| 277 | */ |
| 278 | static inline void *ht_get_internal(const hash_table *ht, |
| 279 | const uint8_t *key, |
| 280 | uint32_t hash_val) |
| 281 | { |
| 282 | ht_block *tmp; |
| 283 | ht_block *ret; |
| 284 | ret = get_key_loc_in_chain( |
| 285 | ht, |
| 286 | key, |
| 287 | ht->look_up_entries_tbl[hash_val].next_chain, |
| 288 | &tmp); |
| 289 | if (ret != NULL) |
| 290 | { |
| 291 | return get_ht_data_ptr(ht,ret); |
| 292 | } |
| 293 | else |
| 294 | { |
| 295 | return ret; |
| 296 | } |
| 297 | } |
| 298 | |
| 299 | void *hash_table_get(const hash_table *ht, const uint8_t *key) |
| 300 | { |
| 301 | uint32_t hashVal = get_hash_val_for_key(ht, key); |
| 302 | return ht_get_internal(ht,key,hashVal); |
| 303 | } |
| 304 | |
| 305 | void *hash_table_put(hash_table *ht, const uint8_t *key, const void *val) |
| 306 | { |
| 307 | void *ret_block; |
| 308 | uint32_t hash_val; |
| 309 | if (ht->ht_cur_entries >= ht->ht_max_data_entries) |
| 310 | { |
| 311 | return NULL; |
| 312 | } |
| 313 | hash_val = get_hash_val_for_key(ht, key); |
| 314 | |
| 315 | ret_block = ht_get_internal((const hash_table *) ht, key, hash_val); |
| 316 | if (ret_block != NULL) |
| 317 | { |
| 318 | /* replace existing value with new value */ |
| 319 | if (val != NULL) |
| 320 | { |
| 321 | memcpy(ret_block, val, ht->obj_len); |
| 322 | } |
| 323 | else |
| 324 | { |
| 325 | memset(ret_block, 0, ht->obj_len); |
| 326 | } |
| 327 | return ret_block; |
| 328 | } |
| 329 | else |
| 330 | { |
| 331 | ht_block *new_block=fill_ht_block( |
| 332 | ht->look_up_entries_tbl[hash_val].next_chain, ht, key, val); |
| 333 | if (new_block != NULL) |
| 334 | { |
| 335 | ht->look_up_entries_tbl[hash_val].next_chain = new_block; |
| 336 | ht->ht_cur_entries++; |
| 337 | return get_ht_data_ptr(ht,new_block); |
| 338 | } |
| 339 | else |
| 340 | { |
| 341 | return NULL; |
| 342 | } |
| 343 | } |
| 344 | |
| 345 | } |
| 346 | |
| 347 | ht_iterator ht_iterator_get(const hash_table *ht) |
| 348 | { |
| 349 | ht_iterator to_ret; |
| 350 | to_ret.ht = ht; |
| 351 | to_ret.cur_idx = 0; |
| 352 | to_ret.removed_at = BCMOS_FALSE; |
| 353 | to_ret.still_valid = BCMOS_TRUE; |
| 354 | to_ret.cur_block = NULL; |
| 355 | return to_ret; |
| 356 | } |
| 357 | |
| 358 | ht_iterator ht_iterator_get_by_key(const hash_table *ht, const uint8_t *key) |
| 359 | { |
| 360 | ht_block *tmp; |
| 361 | uint32_t hash_val = get_hash_val_for_key(ht, key); |
| 362 | ht_iterator to_ret = {}; |
| 363 | to_ret.ht = ht; |
| 364 | to_ret.removed_at = BCMOS_FALSE; |
| 365 | to_ret.cur_block = get_key_loc_in_chain(ht, key, ht->look_up_entries_tbl[hash_val].next_chain, &tmp); |
| 366 | to_ret.still_valid = (to_ret.cur_block != NULL); |
| 367 | to_ret.cur_idx = hash_val; |
| 368 | |
| 369 | return to_ret; |
| 370 | } |
| 371 | |
| 372 | /** Advance linear scan iterator |
| 373 | * \param[in] it Iterator to advance |
| 374 | */ |
| 375 | static void ht_iterator_scan_adv(ht_iterator *it) |
| 376 | { |
| 377 | if (it->cur_block != NULL) |
| 378 | { |
| 379 | it->cur_block = it->cur_block->next_chain; |
| 380 | if (it->cur_block != NULL) |
| 381 | { |
| 382 | it->still_valid = BCMOS_TRUE; |
| 383 | return; |
| 384 | } |
| 385 | else |
| 386 | { |
| 387 | it->cur_idx++; |
| 388 | } |
| 389 | } |
| 390 | /* find non null entry */ |
| 391 | while (it->cur_idx < it->ht->ht_lookup_tbl_entries) |
| 392 | { |
| 393 | if (it->ht->look_up_entries_tbl[it->cur_idx].next_chain != NULL) |
| 394 | { |
| 395 | it->cur_block = it->ht->look_up_entries_tbl[it->cur_idx].next_chain; |
| 396 | it->still_valid = BCMOS_TRUE; |
| 397 | return; |
| 398 | } |
| 399 | else |
| 400 | { |
| 401 | it->cur_idx++; |
| 402 | } |
| 403 | } |
| 404 | it->still_valid = BCMOS_FALSE; |
| 405 | } |
| 406 | |
| 407 | void ht_iterator_deref(const ht_iterator *hti, uint8_t **key, void **obj) |
| 408 | { |
| 409 | if (!hti->still_valid) |
| 410 | { |
| 411 | BCMOS_TRACE_ERR("%s: Invalid deref\n", __FUNCTION__); |
| 412 | } |
| 413 | else |
| 414 | { |
| 415 | *key = get_key_from_block_in_table(hti->ht, hti->cur_block); |
| 416 | *obj = get_ht_data_ptr(hti->ht, hti->cur_block); /* to data */ |
| 417 | } |
| 418 | } |
| 419 | |
| 420 | void ht_iterator_remove_at(hash_table *ht, ht_iterator *it) |
| 421 | { |
| 422 | if (ht != it->ht) |
| 423 | { |
| 424 | BCMOS_TRACE_ERR("%s: Incorrect writeable hash table pointer\n", __FUNCTION__); |
| 425 | } |
| 426 | else if (it->removed_at) |
| 427 | { |
| 428 | BCMOS_TRACE_ERR("%s: No delete twice\n", __FUNCTION__); |
| 429 | } |
| 430 | else |
| 431 | { |
| 432 | uint8_t *key; |
| 433 | uint8_t *obj; |
| 434 | ht_iterator_deref(it, &key, (void **) &obj); |
| 435 | it->removed_at = BCMOS_TRUE; |
| 436 | it->still_valid = ht_iterator_next(it); |
| 437 | if (!hash_table_remove(ht, key)) |
| 438 | { |
| 439 | BCMOS_TRACE_ERR("%s: Remove error\n", __FUNCTION__); |
| 440 | } |
| 441 | } |
| 442 | } |
| 443 | |
| 444 | bcmos_bool ht_iterator_next(ht_iterator *it) |
| 445 | { |
| 446 | if (it->still_valid) |
| 447 | { |
| 448 | if (it->removed_at) |
| 449 | { |
| 450 | it->removed_at = BCMOS_FALSE; |
| 451 | } |
| 452 | else |
| 453 | { |
| 454 | ht_iterator_scan_adv(it); |
| 455 | } |
| 456 | } |
| 457 | return it->still_valid; /* No entry found */ |
| 458 | } |
| 459 | |
| 460 | void hash_table_clear(hash_table *ht) |
| 461 | { |
| 462 | ht_iterator it = ht_iterator_get(ht); |
| 463 | while (ht_iterator_next(&it)) |
| 464 | { |
| 465 | ht_iterator_remove_at(ht, &it); |
| 466 | } |
| 467 | } |