diff --git a/doc/Changelog b/doc/Changelog index bb06725a8..5716f1392 100644 --- a/doc/Changelog +++ b/doc/Changelog @@ -2,6 +2,7 @@ - #1217. DNSCrypt support, with --enable-dnscrypt, libsodium and then enabled in the config file from Manu Bretelle. - make depend, autoconf, remove warnings about statement before var. + - lru_demote and lruhash_insert_or_retrieve functions for getdns. 17 March 2017: Wouter - Patch for view functionality for local-data-ptr from Björn Ketelaars. diff --git a/util/storage/lruhash.c b/util/storage/lruhash.c index 97e999605..cef9fb0b8 100644 --- a/util/storage/lruhash.c +++ b/util/storage/lruhash.c @@ -543,3 +543,89 @@ lruhash_traverse(struct lruhash* h, int wr, } lock_quick_unlock(&h->lock); } + +/* + * Demote: the opposite of touch, move an entry to the bottom + * of the LRU pile. + */ + +void +lru_demote(struct lruhash* table, struct lruhash_entry* entry) +{ + log_assert(table && entry); + if (entry == table->lru_end) + return; /* nothing to do */ + /* remove from current lru position */ + lru_remove(table, entry); + /* add at end */ + entry->lru_next = NULL; + entry->lru_prev = table->lru_end; + + if (table->lru_end == NULL) + { + table->lru_start = entry; + } + else + { + table->lru_end->lru_next = entry; + } + table->lru_end = entry; +} + +struct lruhash_entry* +lruhash_insert_or_retrieve(struct lruhash* table, hashvalue_type hash, + struct lruhash_entry* entry, void* data, void* cb_arg) +{ + struct lruhash_bin* bin; + struct lruhash_entry* found, *reclaimlist = NULL; + size_t need_size; + fptr_ok(fptr_whitelist_hash_sizefunc(table->sizefunc)); + fptr_ok(fptr_whitelist_hash_delkeyfunc(table->delkeyfunc)); + fptr_ok(fptr_whitelist_hash_deldatafunc(table->deldatafunc)); + fptr_ok(fptr_whitelist_hash_compfunc(table->compfunc)); + fptr_ok(fptr_whitelist_hash_markdelfunc(table->markdelfunc)); + need_size = table->sizefunc(entry->key, data); + if (cb_arg == NULL) cb_arg = table->cb_arg; + + /* find bin */ + lock_quick_lock(&table->lock); + bin = &table->array[hash & table->size_mask]; + lock_quick_lock(&bin->lock); + + /* see if entry exists already */ + if ((found = bin_find_entry(table, bin, hash, entry->key)) != NULL) { + /* if so: keep the existing data - acquire a writelock */ + lock_rw_wrlock(&found->lock); + } + else + { + /* if not: add to bin */ + entry->overflow_next = bin->overflow_list; + bin->overflow_list = entry; + lru_front(table, entry); + table->num++; + table->space_used += need_size; + /* return the entry that was presented, and lock it */ + found = entry; + lock_rw_wrlock(&found->lock); + } + lock_quick_unlock(&bin->lock); + if (table->space_used > table->space_max) + reclaim_space(table, &reclaimlist); + if (table->num >= table->size) + table_grow(table); + lock_quick_unlock(&table->lock); + + /* finish reclaim if any (outside of critical region) */ + while (reclaimlist) { + struct lruhash_entry* n = reclaimlist->overflow_next; + void* d = reclaimlist->data; + (*table->delkeyfunc)(reclaimlist->key, cb_arg); + (*table->deldatafunc)(d, cb_arg); + reclaimlist = n; + } + + /* return the entry that was selected */ + return found; +} + diff --git a/util/storage/lruhash.h b/util/storage/lruhash.h index c39374082..af06b6229 100644 --- a/util/storage/lruhash.h +++ b/util/storage/lruhash.h @@ -301,6 +301,38 @@ void lru_touch(struct lruhash* table, struct lruhash_entry* entry); */ void lruhash_setmarkdel(struct lruhash* table, lruhash_markdelfunc_type md); +/************************* getdns functions ************************/ +/*** these are used by getdns only and not by unbound. ***/ + +/** + * Demote entry, so it becomes the least recently used in the LRU list. + * Caller must hold hash table lock. The entry must be inserted already. + * @param table: hash table. + * @param entry: entry to make last in LRU. + */ +void lru_demote(struct lruhash* table, struct lruhash_entry* entry); + +/** + * Insert a new element into the hashtable, or retrieve the corresponding + * element of it exits. + * + * If key is already present data pointer in that entry is kept. + * If it is not present, a new entry is created. In that case, + * the space calculation function is called with the key, data. + * If necessary the least recently used entries are deleted to make space. + * If necessary the hash array is grown up. + * + * @param table: hash table. + * @param hash: hash value. User calculates the hash. + * @param entry: identifies the entry. + * @param data: the data. + * @param cb_override: if not null overrides the cb_arg for the deletefunc. + * @return: pointer to the existing entry if the key was already present, + * or to the entry argument if it was not. + */ +struct lruhash_entry* lruhash_insert_or_retrieve(struct lruhash* table, hashvalue_type hash, + struct lruhash_entry* entry, void* data, void* cb_arg); + /************************* Internal functions ************************/ /*** these are only exposed for unit tests. ***/