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Diffstat (limited to 'src/vppinfra/bihash_template.h')
| -rw-r--r-- | src/vppinfra/bihash_template.h | 419 |
1 files changed, 419 insertions, 0 deletions
diff --git a/src/vppinfra/bihash_template.h b/src/vppinfra/bihash_template.h new file mode 100644 index 00000000..ea1b6f7b --- /dev/null +++ b/src/vppinfra/bihash_template.h @@ -0,0 +1,419 @@ +/* + Copyright (c) 2014 Cisco and/or its affiliates. + + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. +*/ + +/** @cond DOCUMENTATION_IS_IN_BIHASH_DOC_H */ + +/* + * Note: to instantiate the template multiple times in a single file, + * #undef __included_bihash_template_h__... + */ +#ifndef __included_bihash_template_h__ +#define __included_bihash_template_h__ + +#include <vppinfra/heap.h> +#include <vppinfra/format.h> +#include <vppinfra/pool.h> + +#ifndef BIHASH_TYPE +#error BIHASH_TYPE not defined +#endif + +#define _bv(a,b) a##b +#define __bv(a,b) _bv(a,b) +#define BV(a) __bv(a,BIHASH_TYPE) + +#define _bvt(a,b) a##b##_t +#define __bvt(a,b) _bvt(a,b) +#define BVT(a) __bvt(a,BIHASH_TYPE) + +typedef struct BV (clib_bihash_value) +{ + union + { + BVT (clib_bihash_kv) kvp[BIHASH_KVP_PER_PAGE]; + struct BV (clib_bihash_value) * next_free; + }; +} BVT (clib_bihash_value); + +#if BIHASH_KVP_CACHE_SIZE > 5 +#error Requested KVP cache LRU data exceeds 16 bits +#endif + +typedef struct +{ + union + { + struct + { + u32 offset; + u8 linear_search; + u8 log2_pages; + u16 cache_lru; + }; + u64 as_u64; + }; +#if BIHASH_KVP_CACHE_SIZE > 0 + BVT (clib_bihash_kv) cache[BIHASH_KVP_CACHE_SIZE]; +#endif +} BVT (clib_bihash_bucket); + +typedef struct +{ + BVT (clib_bihash_value) * values; + BVT (clib_bihash_bucket) * buckets; + volatile u32 *writer_lock; + + BVT (clib_bihash_value) ** working_copies; + int *working_copy_lengths; + BVT (clib_bihash_bucket) saved_bucket; + + u32 nbuckets; + u32 log2_nbuckets; + u32 linear_buckets; + u8 *name; + + u64 cache_hits; + u64 cache_misses; + + BVT (clib_bihash_value) ** freelists; + void *mheap; + +} BVT (clib_bihash); + + +static inline void +BV (clib_bihash_update_lru) (BVT (clib_bihash_bucket) * b, u8 slot) +{ + u16 value, tmp, mask; + u8 found_lru_pos; + u16 save_hi; + + if (BIHASH_KVP_CACHE_SIZE < 2) + return; + + ASSERT (slot < BIHASH_KVP_CACHE_SIZE); + + /* First, find the slot in cache_lru */ + mask = slot; + if (BIHASH_KVP_CACHE_SIZE > 1) + mask |= slot << 3; + if (BIHASH_KVP_CACHE_SIZE > 2) + mask |= slot << 6; + if (BIHASH_KVP_CACHE_SIZE > 3) + mask |= slot << 9; + if (BIHASH_KVP_CACHE_SIZE > 4) + mask |= slot << 12; + + value = b->cache_lru; + tmp = value ^ mask; + + /* Already the most-recently used? */ + if ((tmp & 7) == 0) + return; + + found_lru_pos = ((tmp & (7 << 3)) == 0) ? 1 : 0; + if (BIHASH_KVP_CACHE_SIZE > 2) + found_lru_pos = ((tmp & (7 << 6)) == 0) ? 2 : found_lru_pos; + if (BIHASH_KVP_CACHE_SIZE > 3) + found_lru_pos = ((tmp & (7 << 9)) == 0) ? 3 : found_lru_pos; + if (BIHASH_KVP_CACHE_SIZE > 4) + found_lru_pos = ((tmp & (7 << 12)) == 0) ? 4 : found_lru_pos; + + ASSERT (found_lru_pos); + + /* create a mask to kill bits in or above slot */ + mask = 0xFFFF << found_lru_pos; + mask <<= found_lru_pos; + mask <<= found_lru_pos; + mask ^= 0xFFFF; + tmp = value & mask; + + /* Save bits above slot */ + mask ^= 0xFFFF; + mask <<= 3; + save_hi = value & mask; + + value = save_hi | (tmp << 3) | slot; + + b->cache_lru = value; +} + +void +BV (clib_bihash_update_lru_not_inline) (BVT (clib_bihash_bucket) * b, + u8 slot); + +static inline u8 BV (clib_bihash_get_lru) (BVT (clib_bihash_bucket) * b) +{ +#if BIHASH_KVP_CACHE_SIZE > 0 + return (b->cache_lru >> (3 * (BIHASH_KVP_CACHE_SIZE - 1))) & 7; +#else + return 0; +#endif +} + +static inline void BV (clib_bihash_reset_cache) (BVT (clib_bihash_bucket) * b) +{ +#if BIHASH_KVP_CACHE_SIZE > 0 + u16 initial_lru_value; + + memset (b->cache, 0xff, sizeof (b->cache)); + + /* + * We'll want the cache to be loaded from slot 0 -> slot N, so + * the initial LRU order is reverse index order. + */ + if (BIHASH_KVP_CACHE_SIZE == 1) + initial_lru_value = 0; + else if (BIHASH_KVP_CACHE_SIZE == 2) + initial_lru_value = (0 << 3) | (1 << 0); + else if (BIHASH_KVP_CACHE_SIZE == 3) + initial_lru_value = (0 << 6) | (1 << 3) | (2 << 0); + else if (BIHASH_KVP_CACHE_SIZE == 4) + initial_lru_value = (0 << 9) | (1 << 6) | (2 << 3) | (3 << 0); + else if (BIHASH_KVP_CACHE_SIZE == 5) + initial_lru_value = (0 << 12) | (1 << 9) | (2 << 6) | (3 << 3) | (4 << 0); + + b->cache_lru = initial_lru_value; +#endif +} + +static inline int BV (clib_bihash_lock_bucket) (BVT (clib_bihash_bucket) * b) +{ + BVT (clib_bihash_bucket) tmp_b; + u64 rv; + + tmp_b.as_u64 = 0; + tmp_b.cache_lru = 1 << 15; + + rv = __sync_fetch_and_or (&b->as_u64, tmp_b.as_u64); + tmp_b.as_u64 = rv; + /* Was already locked? */ + if (tmp_b.cache_lru & (1 << 15)) + return 0; + return 1; +} + +static inline void BV (clib_bihash_unlock_bucket) + (BVT (clib_bihash_bucket) * b) +{ + BVT (clib_bihash_bucket) tmp_b; + + tmp_b.as_u64 = b->as_u64; + tmp_b.cache_lru &= ~(1 << 15); + b->as_u64 = tmp_b.as_u64; +} + +static inline void *BV (clib_bihash_get_value) (BVT (clib_bihash) * h, + uword offset) +{ + u8 *hp = h->mheap; + u8 *vp = hp + offset; + + return (void *) vp; +} + +static inline uword BV (clib_bihash_get_offset) (BVT (clib_bihash) * h, + void *v) +{ + u8 *hp, *vp; + + hp = (u8 *) h->mheap; + vp = (u8 *) v; + + ASSERT ((vp - hp) < 0x100000000ULL); + return vp - hp; +} + +void BV (clib_bihash_init) + (BVT (clib_bihash) * h, char *name, u32 nbuckets, uword memory_size); + +void BV (clib_bihash_free) (BVT (clib_bihash) * h); + +int BV (clib_bihash_add_del) (BVT (clib_bihash) * h, + BVT (clib_bihash_kv) * add_v, int is_add); +int BV (clib_bihash_search) (BVT (clib_bihash) * h, + BVT (clib_bihash_kv) * search_v, + BVT (clib_bihash_kv) * return_v); + +void BV (clib_bihash_foreach_key_value_pair) (BVT (clib_bihash) * h, + void *callback, void *arg); + +format_function_t BV (format_bihash); +format_function_t BV (format_bihash_kvp); +format_function_t BV (format_bihash_lru); + +static inline int BV (clib_bihash_search_inline) + (BVT (clib_bihash) * h, BVT (clib_bihash_kv) * key_result) +{ + u64 hash; + u32 bucket_index; + BVT (clib_bihash_value) * v; + BVT (clib_bihash_bucket) * b; +#if BIHASH_KVP_CACHE_SIZE > 0 + BVT (clib_bihash_kv) * kvp; +#endif + int i, limit; + + hash = BV (clib_bihash_hash) (key_result); + + bucket_index = hash & (h->nbuckets - 1); + b = &h->buckets[bucket_index]; + + if (b->offset == 0) + return -1; + +#if BIHASH_KVP_CACHE_SIZE > 0 + /* Check the cache, if not currently locked */ + if (PREDICT_TRUE ((b->cache_lru & (1 << 15)) == 0)) + { + limit = BIHASH_KVP_CACHE_SIZE; + kvp = b->cache; + for (i = 0; i < limit; i++) + { + if (BV (clib_bihash_key_compare) (kvp[i].key, key_result->key)) + { + *key_result = kvp[i]; + h->cache_hits++; + return 0; + } + } + } +#endif + + hash >>= h->log2_nbuckets; + + v = BV (clib_bihash_get_value) (h, b->offset); + + /* If the bucket has unresolvable collisions, use linear search */ + limit = BIHASH_KVP_PER_PAGE; + v += (b->linear_search == 0) ? hash & ((1 << b->log2_pages) - 1) : 0; + if (PREDICT_FALSE (b->linear_search)) + limit <<= b->log2_pages; + + for (i = 0; i < limit; i++) + { + if (BV (clib_bihash_key_compare) (v->kvp[i].key, key_result->key)) + { + *key_result = v->kvp[i]; + +#if BIHASH_KVP_CACHE_SIZE > 0 + u8 cache_slot; + /* Try to lock the bucket */ + if (BV (clib_bihash_lock_bucket) (b)) + { + cache_slot = BV (clib_bihash_get_lru) (b); + b->cache[cache_slot] = v->kvp[i]; + BV (clib_bihash_update_lru) (b, cache_slot); + + /* Unlock the bucket */ + BV (clib_bihash_unlock_bucket) (b); + h->cache_misses++; + } +#endif + return 0; + } + } + return -1; +} + +static inline int BV (clib_bihash_search_inline_2) + (BVT (clib_bihash) * h, + BVT (clib_bihash_kv) * search_key, BVT (clib_bihash_kv) * valuep) +{ + u64 hash; + u32 bucket_index; + BVT (clib_bihash_value) * v; + BVT (clib_bihash_bucket) * b; +#if BIHASH_KVP_CACHE_SIZE > 0 + BVT (clib_bihash_kv) * kvp; +#endif + int i, limit; + + ASSERT (valuep); + + hash = BV (clib_bihash_hash) (search_key); + + bucket_index = hash & (h->nbuckets - 1); + b = &h->buckets[bucket_index]; + + if (b->offset == 0) + return -1; + + /* Check the cache, if currently unlocked */ +#if BIHASH_KVP_CACHE_SIZE > 0 + if (PREDICT_TRUE ((b->cache_lru & (1 << 15)) == 0)) + { + limit = BIHASH_KVP_CACHE_SIZE; + kvp = b->cache; + for (i = 0; i < limit; i++) + { + if (BV (clib_bihash_key_compare) (kvp[i].key, search_key->key)) + { + *valuep = kvp[i]; + h->cache_hits++; + return 0; + } + } + } +#endif + + hash >>= h->log2_nbuckets; + v = BV (clib_bihash_get_value) (h, b->offset); + + /* If the bucket has unresolvable collisions, use linear search */ + limit = BIHASH_KVP_PER_PAGE; + v += (b->linear_search == 0) ? hash & ((1 << b->log2_pages) - 1) : 0; + if (PREDICT_FALSE (b->linear_search)) + limit <<= b->log2_pages; + + for (i = 0; i < limit; i++) + { + if (BV (clib_bihash_key_compare) (v->kvp[i].key, search_key->key)) + { + *valuep = v->kvp[i]; + +#if BIHASH_KVP_CACHE_SIZE > 0 + u8 cache_slot; + + /* Try to lock the bucket */ + if (BV (clib_bihash_lock_bucket) (b)) + { + cache_slot = BV (clib_bihash_get_lru) (b); + b->cache[cache_slot] = v->kvp[i]; + BV (clib_bihash_update_lru) (b, cache_slot); + + /* Reenable the cache */ + BV (clib_bihash_unlock_bucket) (b); + h->cache_misses++; + } +#endif + return 0; + } + } + return -1; +} + +#endif /* __included_bihash_template_h__ */ + +/** @endcond */ + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ |