From 1852910ef0fd7393da62b88aee66ee092208748e Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 27 Apr 2024 12:41:58 +0200 Subject: Adding upstream version 5.3.1. Signed-off-by: Daniel Baumann --- lib/cache/cdb_api.h | 97 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 97 insertions(+) create mode 100644 lib/cache/cdb_api.h (limited to 'lib/cache/cdb_api.h') diff --git a/lib/cache/cdb_api.h b/lib/cache/cdb_api.h new file mode 100644 index 0000000..d94ea5e --- /dev/null +++ b/lib/cache/cdb_api.h @@ -0,0 +1,97 @@ +/* Copyright (C) 2016-2017 CZ.NIC, z.s.p.o. + * SPDX-License-Identifier: GPL-3.0-or-later +*/ + +#pragma once + +#include + +#include + +/* Cache options. */ +struct kr_cdb_opts { + const char *path; /*!< Cache URI path. */ + size_t maxsize; /*!< Suggested cache size in bytes; pass 0 to keep unchanged/default. */ +}; + +struct kr_cdb_stats { + uint64_t open; + uint64_t close; + uint64_t count; + uint64_t count_entries; + uint64_t clear; + uint64_t commit; + uint64_t read; + uint64_t read_miss; + uint64_t write; + uint64_t remove; + uint64_t remove_miss; + uint64_t match; + uint64_t match_miss; + uint64_t read_leq; + uint64_t read_leq_miss; + double usage_percent; +}; + +/*! Pointer to a cache structure. + * + * This struct is opaque and never defined; the purpose is to get better + * type safety than with void *. + */ +typedef struct kr_cdb *kr_cdb_pt; + +/*! Cache database API. + * This is a simplified version of generic DB API from libknot, + * that is tailored to caching purposes. + */ +struct kr_cdb_api { + const char *name; + + /* Context operations */ + + int (*open)(kr_cdb_pt *db, struct kr_cdb_stats *stat, struct kr_cdb_opts *opts, knot_mm_t *mm); + void (*close)(kr_cdb_pt db, struct kr_cdb_stats *stat); + int (*count)(kr_cdb_pt db, struct kr_cdb_stats *stat); + int (*clear)(kr_cdb_pt db, struct kr_cdb_stats *stat); + + /** Run after a row of operations to release transaction/lock if needed. */ + int (*commit)(kr_cdb_pt db, struct kr_cdb_stats *stat); + + /* Data access */ + + int (*read)(kr_cdb_pt db, struct kr_cdb_stats *stat, + const knot_db_val_t *key, knot_db_val_t *val, int maxcount); + int (*write)(kr_cdb_pt db, struct kr_cdb_stats *stat, const knot_db_val_t *key, + knot_db_val_t *val, int maxcount); + + /** Remove maxcount keys. + * \returns the number of succesfully removed keys or the first error code + * It returns on first error, but ENOENT is not considered an error. */ + int (*remove)(kr_cdb_pt db, struct kr_cdb_stats *stat, + knot_db_val_t keys[], int maxcount); + + /* Specialised operations */ + + /** Find key-value pairs that are prefixed by the given key, limited by maxcount. + * \return the number of pairs or negative error. */ + int (*match)(kr_cdb_pt db, struct kr_cdb_stats *stat, + knot_db_val_t *key, knot_db_val_t keyval[][2], int maxcount); + + /** Less-or-equal search (lexicographic ordering). + * On successful return, key->data and val->data point to DB-owned data. + * return: 0 for equality, > 0 for less, < 0 kr_error */ + int (*read_leq)(kr_cdb_pt db, struct kr_cdb_stats *stat, + knot_db_val_t *key, knot_db_val_t *val); + + /** Return estimated space usage (0--100). */ + double (*usage_percent)(kr_cdb_pt db); + + /** Return the current cache size limit in bytes; could be cached by check_health(). */ + size_t (*get_maxsize)(kr_cdb_pt db); + + /** Perform maintenance. + * In LMDB case it checks whether data.mdb is still the same + * and reopens it if it isn't; it errors out if the file doesn't exist anymore. + * \return 0 if OK, 1 if reopened OK, < 0 kr_error */ + int (*check_health)(kr_cdb_pt db, struct kr_cdb_stats *stat); +}; -- cgit v1.2.3