/* Copyright (C) 2014-2017 CZ.NIC, z.s.p.o. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . */ #pragma once #include #include #include #include "lib/cache/cdb_api.h" #include "lib/defines.h" #include "contrib/ucw/config.h" /*uint*/ /** When knot_pkt is passed from cache without ->wire, this is the ->size. */ static const size_t PKT_SIZE_NOWIRE = -1; #include "lib/module.h" /* Prototypes for the 'cache' module implementation. */ int cache_peek(kr_layer_t *ctx, knot_pkt_t *pkt); int cache_stash(kr_layer_t *ctx, knot_pkt_t *pkt); /** * Cache structure, keeps API, instance and metadata. */ struct kr_cache { knot_db_t *db; /**< Storage instance */ const struct kr_cdb_api *api; /**< Storage engine */ struct { uint32_t hit; /**< Number of cache hits */ uint32_t miss; /**< Number of cache misses */ uint32_t insert; /**< Number of insertions */ uint32_t delete; /**< Number of deletions */ } stats; uint32_t ttl_min, ttl_max; /**< TTL limits */ /* A pair of stamps for detection of real-time shifts during runtime. */ struct timeval checkpoint_walltime; /**< Wall time on the last check-point. */ uint64_t checkpoint_monotime; /**< Monotonic milliseconds on the last check-point. */ }; /** * Open/create cache with provided storage options. * @param cache cache structure to be initialized * @param api storage engine API * @param opts storage-specific options (may be NULL for default) * @param mm memory context. * @return 0 or an error code */ KR_EXPORT int kr_cache_open(struct kr_cache *cache, const struct kr_cdb_api *api, struct kr_cdb_opts *opts, knot_mm_t *mm); /** * Path to cache file to remove on critical out-of-space error. (do NOT modify it) */ KR_EXPORT extern const char *kr_cache_emergency_file_to_remove; /** * Close persistent cache. * @note This doesn't clear the data, just closes the connection to the database. * @param cache structure */ KR_EXPORT void kr_cache_close(struct kr_cache *cache); /** Run after a row of operations to release transaction/lock if needed. */ KR_EXPORT int kr_cache_sync(struct kr_cache *cache); /** * Return true if cache is open and enabled. */ static inline bool kr_cache_is_open(struct kr_cache *cache) { return cache->db != NULL; } /** (Re)set the time pair to the current values. */ static inline void kr_cache_make_checkpoint(struct kr_cache *cache) { cache->checkpoint_monotime = kr_now(); gettimeofday(&cache->checkpoint_walltime, NULL); } /** * Insert RRSet into cache, replacing any existing data. * @param cache cache structure * @param rr inserted RRSet * @param rrsig RRSIG for inserted RRSet (optional) * @param rank rank of the data * @param timestamp current time * @return 0 or an errcode */ KR_EXPORT int kr_cache_insert_rr(struct kr_cache *cache, const knot_rrset_t *rr, const knot_rrset_t *rrsig, uint8_t rank, uint32_t timestamp); /** * Clear all items from the cache. * @param cache cache structure * @return 0 or an errcode */ KR_EXPORT int kr_cache_clear(struct kr_cache *cache); /* ** This interface is temporary. ** */ struct kr_cache_p { uint32_t time; /**< The time of inception. */ uint32_t ttl; /**< TTL at inception moment. Assuming it fits into int32_t ATM. */ uint8_t rank; /**< See enum kr_rank */ struct { /* internal: pointer to eh struct */ void *raw_data, *raw_bound; }; }; KR_EXPORT int kr_cache_peek_exact(struct kr_cache *cache, const knot_dname_t *name, uint16_t type, struct kr_cache_p *peek); /* Parameters (qry, name, type) are used for timestamp and stale-serving decisions. */ KR_EXPORT int32_t kr_cache_ttl(const struct kr_cache_p *peek, const struct kr_query *qry, const knot_dname_t *name, uint16_t type); KR_EXPORT int kr_cache_materialize(knot_rdataset_t *dst, const struct kr_cache_p *ref, knot_mm_t *pool); /** * Remove an entry from cache. * @param cache cache structure * @param name dname * @param type rr type * @return number of deleted records, or negative error code * @note only "exact hits" are considered ATM, and * some other information may be removed alongside. */ KR_EXPORT int kr_cache_remove(struct kr_cache *cache, const knot_dname_t *name, uint16_t type); /** * Get keys matching a dname lf prefix * @param cache cache structure * @param name dname * @param exact_name whether to only consider exact name matches * @param keyval matched key-value pairs * @param maxcount limit on the number of returned key-value pairs * @return result count or an errcode * @note the cache keys are matched by prefix, i.e. it very much depends * on their structure; CACHE_KEY_DEF. */ KR_EXPORT int kr_cache_match(struct kr_cache *cache, const knot_dname_t *name, bool exact_name, knot_db_val_t keyval[][2], int maxcount); /** * Remove a subtree in cache. It's like _match but removing them instead of returning. * @return number of deleted entries or an errcode */ KR_EXPORT int kr_cache_remove_subtree(struct kr_cache *cache, const knot_dname_t *name, bool exact_name, int maxcount); /** * Find the closest cached zone apex for a name (in cache). * @param is_DS start searching one name higher * @return the number of labels to remove from the name, or negative error code * @note timestamp is found by a syscall, and stale-serving is not considered */ KR_EXPORT int kr_cache_closest_apex(struct kr_cache *cache, const knot_dname_t *name, bool is_DS, knot_dname_t **apex); /** * Unpack dname and type from db key * @param key db key representation * @param buf output buffer of domain name in dname format * @param type output for type * @return length of dname or an errcode * @note only "exact hits" are considered ATM, moreover xNAME records * are "hidden" as NS. (see comments in struct entry_h) */ KR_EXPORT int kr_unpack_cache_key(knot_db_val_t key, knot_dname_t *buf, uint16_t *type);