diff options
Diffstat (limited to 'hicn-plugin/src/cache_policies/cs_lru.c')
| -rwxr-xr-x | hicn-plugin/src/cache_policies/cs_lru.c | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/hicn-plugin/src/cache_policies/cs_lru.c b/hicn-plugin/src/cache_policies/cs_lru.c new file mode 100755 index 000000000..f35bee3c9 --- /dev/null +++ b/hicn-plugin/src/cache_policies/cs_lru.c @@ -0,0 +1,213 @@ +/* + * Copyright (c) 2017-2019 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. + */ + +#include "../hashtb.h" +#include "../strategy_dpo_manager.h" +#include "../error.h" +#include "cs_lru.h" +#include "cs_policy.h" + +hicn_cs_policy_vft_t hicn_cs_lru = { + .hicn_cs_insert = &hicn_cs_lru_insert, + .hicn_cs_update = &hicn_cs_lru_update_head, + .hicn_cs_dequeue = &hicn_cs_lru_dequeue, + .hicn_cs_delete_get = &hicn_cs_lru_delete_get, + .hicn_cs_trim = &hicn_cs_lru_trim, +}; + +/* + * Insert a new CS element at the head of the CS LRU + */ +void +hicn_cs_lru_insert (hicn_pit_cs_t * p, hicn_hash_node_t * node, + hicn_pcs_entry_t * pcs, hicn_cs_policy_t * policy_state) +{ + hicn_hash_node_t *lrunode; + hicn_pcs_entry_t *lrupcs; + u32 idx; + + idx = hicn_hashtb_node_idx_from_node (p->pcs_table, node); + + if (policy_state->head != 0) + { + lrunode = hicn_hashtb_node_from_idx (p->pcs_table, policy_state->head); + lrupcs = hicn_pit_get_data (lrunode); + + ASSERT (lrupcs->u.cs.cs_lru_prev == 0); + lrupcs->u.cs.cs_lru_prev = idx; + + pcs->u.cs.cs_lru_prev = 0; + pcs->u.cs.cs_lru_next = policy_state->head; + + policy_state->head = idx; + } + else + { + ASSERT (policy_state->tail == 0); /* We think the list is + * empty */ + + policy_state->head = policy_state->tail = idx; + + pcs->u.cs.cs_lru_next = pcs->u.cs.cs_lru_prev = 0; + } + + policy_state->count++; +} + +void +hicn_cs_lru_delete_get (hicn_pit_cs_t * p, hicn_cs_policy_t * policy_state, + hicn_hash_node_t ** nodep, + hicn_pcs_entry_t ** pcs_entry, + hicn_hash_entry_t ** hash_entry) +{ + *nodep = hicn_hashtb_node_from_idx (p->pcs_table, policy_state->tail); + *pcs_entry = hicn_pit_get_data (*nodep); + + *hash_entry = hicn_hashtb_get_entry (p->pcs_table, (*nodep)->entry_idx, + (*nodep)->bucket_id, + (*nodep)->hn_flags & + HICN_HASH_NODE_OVERFLOW_BUCKET); +} + +/* + * Dequeue an LRU element, for example when it has expired. + */ +void +hicn_cs_lru_dequeue (hicn_pit_cs_t * pit, hicn_hash_node_t * pnode, + hicn_pcs_entry_t * pcs, hicn_cs_policy_t * lru) +{ + hicn_hash_node_t *lrunode; + hicn_pcs_entry_t *lrupcs; + + if (pcs->u.cs.cs_lru_prev != 0) + { + /* Not already on the head of the LRU */ + lrunode = hicn_hashtb_node_from_idx (pit->pcs_table, + pcs->u.cs.cs_lru_prev); + lrupcs = hicn_pit_get_data (lrunode); + + lrupcs->u.cs.cs_lru_next = pcs->u.cs.cs_lru_next; + } + else + { + ASSERT (lru->head == + hicn_hashtb_node_idx_from_node (pit->pcs_table, pnode)); + lru->head = pcs->u.cs.cs_lru_next; + } + + if (pcs->u.cs.cs_lru_next != 0) + { + /* Not already the end of the LRU */ + lrunode = hicn_hashtb_node_from_idx (pit->pcs_table, + pcs->u.cs.cs_lru_next); + lrupcs = hicn_pit_get_data (lrunode); + + lrupcs->u.cs.cs_lru_prev = pcs->u.cs.cs_lru_prev; + } + else + { + /* This was the last LRU element */ + ASSERT (lru->tail == + hicn_hashtb_node_idx_from_node (pit->pcs_table, pnode)); + lru->tail = pcs->u.cs.cs_lru_prev; + } + + pcs->u.cs.cs_lru_next = pcs->u.cs.cs_lru_prev = 0; + lru->count--; +} + +/* + * Move a CS LRU element to the head, probably after it's been used. + */ +void +hicn_cs_lru_update_head (hicn_pit_cs_t * pit, hicn_hash_node_t * pnode, + hicn_pcs_entry_t * pcs, hicn_cs_policy_t * lru) +{ + if (pcs->u.cs.cs_lru_prev != 0) + { + /* + * Not already on the head of the LRU, detach it from its + * current position + */ + hicn_cs_lru_dequeue (pit, pnode, pcs, lru); + + /* Now detached from the list; attach at head */ + hicn_cs_lru_insert (pit, pnode, pcs, lru); + + } + else + { + ASSERT (lru->head == + hicn_hashtb_node_idx_from_node (pit->pcs_table, pnode)); + } +} + +/* + * Remove a batch of nodes from the CS LRU, copying their node indexes into + * the caller's array. We expect this is done when the LRU size exceeds the + * CS's limit. Return the number of removed nodes. + */ +int +hicn_cs_lru_trim (hicn_pit_cs_t * pit, u32 * node_list, int sz, + hicn_cs_policy_t * lru) +{ + hicn_hash_node_t *lrunode; + hicn_pcs_entry_t *lrupcs; + u32 idx; + int i; + + idx = lru->tail; + + for (i = 0; i < sz; i++) + { + + if (idx == 0) + { + break; + } + lrunode = hicn_hashtb_node_from_idx (pit->pcs_table, idx); + lrupcs = hicn_pit_get_data (lrunode); + + node_list[i] = idx; + + idx = lrupcs->u.cs.cs_lru_prev; + lrupcs->u.cs.cs_lru_prev = 0; + lrupcs->u.cs.cs_lru_next = 0; + } + + lru->count -= i; + + lru->tail = idx; + if (idx != 0) + { + lrunode = hicn_hashtb_node_from_idx (pit->pcs_table, idx); + lrupcs = hicn_pit_get_data (lrunode); + + lrupcs->u.cs.cs_lru_next = 0; + } + else + { + /* If the tail is empty, the whole lru is empty */ + lru->head = 0; + } + + return (i); +} + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: eval: (c-set-style "gnu") End: + */ |