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-rw-r--r--src/libknot/db/db.h92
-rw-r--r--src/libknot/db/db_lmdb.c578
-rw-r--r--src/libknot/db/db_lmdb.h73
-rw-r--r--src/libknot/db/db_trie.c176
-rw-r--r--src/libknot/db/db_trie.h40
5 files changed, 959 insertions, 0 deletions
diff --git a/src/libknot/db/db.h b/src/libknot/db/db.h
new file mode 100644
index 0000000..044a2b9
--- /dev/null
+++ b/src/libknot/db/db.h
@@ -0,0 +1,92 @@
+/* Copyright (C) 2017 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+ 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 <https://www.gnu.org/licenses/>.
+ */
+
+/*!
+ * \file
+ *
+ * \brief Structures for binary data handling.
+ *
+ * \addtogroup db
+ * @{
+ */
+
+#pragma once
+
+#include "libknot/mm_ctx.h"
+
+enum {
+ /* Database flags */
+
+ KNOT_DB_RDONLY = 1 << 0, /*!< Read only. */
+ KNOT_DB_SORTED = 1 << 1, /*!< Sorted output. */
+
+ /* Operations */
+
+ KNOT_DB_NOOP = 1 << 2, /*!< No operation. */
+ KNOT_DB_FIRST = 1 << 3, /*!< First entry. */
+ KNOT_DB_LAST = 1 << 4, /*!< Last entry. */
+ KNOT_DB_NEXT = 1 << 5, /*!< Next entry. */
+ KNOT_DB_PREV = 1 << 6, /*!< Previous entry. */
+ KNOT_DB_LEQ = 1 << 7, /*!< Lesser or equal. */
+ KNOT_DB_GEQ = 1 << 8 /*!< Greater or equal. */
+};
+
+typedef void knot_db_t;
+typedef void knot_db_iter_t;
+
+typedef struct knot_db_val {
+ void *data;
+ size_t len;
+} knot_db_val_t;
+
+typedef struct knot_db_txn {
+ knot_db_t *db;
+ void *txn;
+} knot_db_txn_t;
+
+typedef struct knot_db_api {
+ const char *name;
+
+ /* Context operations */
+
+ int (*init)(knot_db_t **db, knot_mm_t *mm, void *opts);
+ void (*deinit)(knot_db_t *db);
+
+ /* Transactions */
+
+ int (*txn_begin)(knot_db_t *db, knot_db_txn_t *txn, unsigned flags);
+ int (*txn_commit)(knot_db_txn_t *txn);
+ void (*txn_abort)(knot_db_txn_t *txn);
+
+ /* Data access */
+
+ int (*count)(knot_db_txn_t *txn);
+ int (*clear)(knot_db_txn_t *txn);
+ int (*find)(knot_db_txn_t *txn, knot_db_val_t *key, knot_db_val_t *val, unsigned flags);
+ int (*insert)(knot_db_txn_t *txn, knot_db_val_t *key, knot_db_val_t *val, unsigned flags);
+ int (*del)(knot_db_txn_t *txn, knot_db_val_t *key);
+
+ /* Iteration */
+
+ knot_db_iter_t *(*iter_begin)(knot_db_txn_t *txn, unsigned flags);
+ knot_db_iter_t *(*iter_seek)(knot_db_iter_t *iter, knot_db_val_t *key, unsigned flags);
+ knot_db_iter_t *(*iter_next)(knot_db_iter_t *iter);
+ int (*iter_key)(knot_db_iter_t *iter, knot_db_val_t *key);
+ int (*iter_val)(knot_db_iter_t *iter, knot_db_val_t *val);
+ void (*iter_finish)(knot_db_iter_t *iter);
+} knot_db_api_t;
+
+/*! @} */
diff --git a/src/libknot/db/db_lmdb.c b/src/libknot/db/db_lmdb.c
new file mode 100644
index 0000000..b5eae09
--- /dev/null
+++ b/src/libknot/db/db_lmdb.c
@@ -0,0 +1,578 @@
+/* Copyright (C) 2022 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+ 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 <https://www.gnu.org/licenses/>.
+ */
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "libknot/attribute.h"
+#include "libknot/errcode.h"
+#include "libknot/db/db_lmdb.h"
+#include "contrib/files.h"
+#include "contrib/mempattern.h"
+
+#include <lmdb.h>
+
+/* Defines */
+#define LMDB_DIR_MODE 0770
+#define LMDB_FILE_MODE 0660
+
+_public_ const unsigned KNOT_DB_LMDB_NOTLS = MDB_NOTLS;
+_public_ const unsigned KNOT_DB_LMDB_RDONLY = MDB_RDONLY;
+_public_ const unsigned KNOT_DB_LMDB_INTEGERKEY = MDB_INTEGERKEY;
+_public_ const unsigned KNOT_DB_LMDB_NOSYNC = MDB_NOSYNC;
+_public_ const unsigned KNOT_DB_LMDB_WRITEMAP = MDB_WRITEMAP;
+_public_ const unsigned KNOT_DB_LMDB_MAPASYNC = MDB_MAPASYNC;
+_public_ const unsigned KNOT_DB_LMDB_DUPSORT = MDB_DUPSORT;
+
+struct lmdb_env
+{
+ bool shared;
+ MDB_dbi dbi;
+ MDB_env *env;
+ knot_mm_t *pool;
+};
+
+/*!
+ * \brief Convert error code returned by LMDB to Knot DNS error code.
+ *
+ * LMDB defines own error codes but uses additional ones from libc:
+ * - LMDB errors do not conflict with Knot DNS ones.
+ * - Significant LMDB errors are mapped to Knot DNS ones.
+ * - Standard errors are converted to negative value to match Knot DNS mapping.
+ */
+static int lmdb_error_to_knot(int error)
+{
+ if (error == MDB_SUCCESS) {
+ return KNOT_EOK;
+ }
+
+ if (error == MDB_NOTFOUND) {
+ return KNOT_ENOENT;
+ }
+
+ if (error == MDB_TXN_FULL) {
+ return KNOT_ELIMIT;
+ }
+
+ if (error == MDB_MAP_FULL || error == ENOSPC) {
+ return KNOT_ESPACE;
+ }
+
+ return -abs(error);
+}
+
+/*! \brief Set the environment map size.
+ * \note This also sets the maximum database size, see mdb_env_set_mapsize
+ */
+static int set_mapsize(MDB_env *env, size_t map_size)
+{
+ long page_size = sysconf(_SC_PAGESIZE);
+ if (page_size <= 0) {
+ return KNOT_ERROR;
+ }
+
+ /* Round to page size. */
+ map_size = (map_size / page_size) * page_size;
+ int ret = mdb_env_set_mapsize(env, map_size);
+ if (ret != MDB_SUCCESS) {
+ return lmdb_error_to_knot(ret);
+ }
+
+ return KNOT_EOK;
+}
+
+/*! \brief Close the database. */
+static void dbase_close(struct lmdb_env *env)
+{
+ mdb_dbi_close(env->env, env->dbi);
+ if (!env->shared) {
+ mdb_env_close(env->env);
+ }
+}
+
+/*! \brief Open database environment. */
+static int dbase_open_env(struct lmdb_env *env, struct knot_db_lmdb_opts *opts)
+{
+ MDB_env *mdb_env = NULL;
+ int ret = mdb_env_create(&mdb_env);
+ if (ret != MDB_SUCCESS) {
+ return lmdb_error_to_knot(ret);
+ }
+
+ ret = make_dir(opts->path, LMDB_DIR_MODE, true);
+ if (ret != KNOT_EOK) {
+ mdb_env_close(mdb_env);
+ return ret;
+ }
+
+ ret = set_mapsize(mdb_env, opts->mapsize);
+ if (ret != KNOT_EOK) {
+ mdb_env_close(mdb_env);
+ return ret;
+ }
+
+ ret = mdb_env_set_maxdbs(mdb_env, opts->maxdbs);
+ if (ret != MDB_SUCCESS) {
+ mdb_env_close(mdb_env);
+ return lmdb_error_to_knot(ret);
+ }
+
+ ret = mdb_env_set_maxreaders(mdb_env, opts->maxreaders);
+ if (ret != MDB_SUCCESS) {
+ mdb_env_close(mdb_env);
+ return lmdb_error_to_knot(ret);
+ }
+
+#ifdef __OpenBSD__
+ /*
+ * Enforce that MDB_WRITEMAP is set.
+ *
+ * MDB assumes a unified buffer cache.
+ *
+ * See https://www.openldap.org/pub/hyc/mdm-paper.pdf section 3.1,
+ * references 17, 18, and 19.
+ *
+ * From Howard Chu: "This requirement can be relaxed in the
+ * current version of the library. If you create the environment
+ * with the MDB_WRITEMAP option then all reads and writes are
+ * performed using mmap, so the file buffer cache is irrelevant.
+ * Of course then you lose the protection that the read-only
+ * map offers."
+ */
+ opts->flags.env |= MDB_WRITEMAP;
+#endif
+
+ ret = mdb_env_open(mdb_env, opts->path, opts->flags.env, LMDB_FILE_MODE);
+ if (ret != MDB_SUCCESS) {
+ mdb_env_close(mdb_env);
+ return lmdb_error_to_knot(ret);
+ }
+
+ /* Keep the environment pointer. */
+ env->env = mdb_env;
+
+ return KNOT_EOK;
+}
+
+static int dbase_open(struct lmdb_env *env, struct knot_db_lmdb_opts *opts)
+{
+ unsigned flags = 0;
+ if (opts->flags.env & KNOT_DB_LMDB_RDONLY) {
+ flags = MDB_RDONLY;
+ }
+
+ /* Open the database. */
+ MDB_txn *txn = NULL;
+ int ret = mdb_txn_begin(env->env, NULL, flags, &txn);
+ if (ret == MDB_READERS_FULL) {
+ int cleared = 0;
+ ret = mdb_reader_check(env->env, &cleared);
+ if (ret == MDB_SUCCESS) {
+ ret = mdb_txn_begin(env->env, NULL, flags, &txn);
+ }
+ }
+ if (ret != MDB_SUCCESS) {
+ mdb_env_close(env->env);
+ return lmdb_error_to_knot(ret);
+ }
+
+ ret = mdb_dbi_open(txn, opts->dbname, opts->flags.db | MDB_CREATE, &env->dbi);
+ if (ret != MDB_SUCCESS) {
+ mdb_txn_abort(txn);
+ mdb_env_close(env->env);
+ return lmdb_error_to_knot(ret);
+ }
+
+ ret = mdb_txn_commit(txn);
+ if (ret != MDB_SUCCESS) {
+ mdb_env_close(env->env);
+ return lmdb_error_to_knot(ret);
+ }
+
+ return KNOT_EOK;
+}
+
+static int init(knot_db_t **db_ptr, knot_mm_t *mm, void *arg)
+{
+ if (db_ptr == NULL || arg == NULL) {
+ return KNOT_EINVAL;
+ }
+
+ struct lmdb_env *env = mm_alloc(mm, sizeof(struct lmdb_env));
+ if (env == NULL) {
+ return KNOT_ENOMEM;
+ }
+
+ memset(env, 0, sizeof(struct lmdb_env));
+ env->pool = mm;
+
+ /* Open new environment. */
+ struct lmdb_env *old_env = *db_ptr;
+ if (old_env == NULL) {
+ int ret = dbase_open_env(env, (struct knot_db_lmdb_opts *)arg);
+ if (ret != KNOT_EOK) {
+ mm_free(mm, env);
+ return ret;
+ }
+ } else {
+ /* Shared environment, this instance just owns the DBI. */
+ env->env = old_env->env;
+ env->shared = true;
+ }
+
+ /* Open the database. */
+ int ret = dbase_open(env, (struct knot_db_lmdb_opts *)arg);
+ if (ret != KNOT_EOK) {
+ mm_free(mm, env);
+ return ret;
+ }
+
+ /* Store the new environment. */
+ *db_ptr = env;
+
+ return KNOT_EOK;
+}
+
+static void deinit(knot_db_t *db)
+{
+ if (db) {
+ struct lmdb_env *env = db;
+
+ dbase_close(env);
+ mm_free(env->pool, env);
+ }
+}
+
+_public_
+int knot_db_lmdb_txn_begin(knot_db_t *db, knot_db_txn_t *txn, knot_db_txn_t *parent,
+ unsigned flags)
+{
+ txn->db = db;
+ txn->txn = NULL;
+
+ unsigned txn_flags = 0;
+ if (flags & KNOT_DB_RDONLY) {
+ txn_flags |= MDB_RDONLY;
+ }
+
+ MDB_txn *parent_txn = (parent != NULL) ? (MDB_txn *)parent->txn : NULL;
+
+ struct lmdb_env *env = db;
+ int ret = mdb_txn_begin(env->env, parent_txn, txn_flags, (MDB_txn **)&txn->txn);
+ if (ret != MDB_SUCCESS) {
+ return lmdb_error_to_knot(ret);
+ }
+
+ return KNOT_EOK;
+}
+
+static int txn_begin(knot_db_t *db, knot_db_txn_t *txn, unsigned flags)
+{
+ return knot_db_lmdb_txn_begin(db, txn, NULL, flags);
+}
+
+static int txn_commit(knot_db_txn_t *txn)
+{
+ int ret = mdb_txn_commit((MDB_txn *)txn->txn);
+ if (ret != MDB_SUCCESS) {
+ return lmdb_error_to_knot(ret);
+ }
+
+ return KNOT_EOK;
+}
+
+static void txn_abort(knot_db_txn_t *txn)
+{
+ mdb_txn_abort((MDB_txn *)txn->txn);
+}
+
+static int count(knot_db_txn_t *txn)
+{
+ struct lmdb_env *env = txn->db;
+
+ MDB_stat stat;
+ int ret = mdb_stat(txn->txn, env->dbi, &stat);
+ if (ret != MDB_SUCCESS) {
+ return lmdb_error_to_knot(ret);
+ }
+
+ return stat.ms_entries;
+}
+
+static int clear(knot_db_txn_t *txn)
+{
+ struct lmdb_env *env = txn->db;
+
+ int ret = mdb_drop(txn->txn, env->dbi, 0);
+ if (ret != MDB_SUCCESS) {
+ return lmdb_error_to_knot(ret);
+ }
+
+ return KNOT_EOK;
+}
+
+static knot_db_iter_t *iter_set(knot_db_iter_t *iter, knot_db_val_t *key, unsigned flags)
+{
+ MDB_cursor *cursor = iter;
+
+ MDB_cursor_op op = MDB_SET;
+ switch(flags) {
+ case KNOT_DB_NOOP: return cursor;
+ case KNOT_DB_FIRST: op = MDB_FIRST; break;
+ case KNOT_DB_LAST: op = MDB_LAST; break;
+ case KNOT_DB_NEXT: op = MDB_NEXT; break;
+ case KNOT_DB_PREV: op = MDB_PREV; break;
+ case KNOT_DB_LEQ:
+ case KNOT_DB_GEQ: op = MDB_SET_RANGE; break;
+ default: break;
+ }
+
+ MDB_val db_key = { 0, NULL };
+ if (key) {
+ db_key.mv_data = key->data;
+ db_key.mv_size = key->len;
+ }
+ MDB_val unused_key = { 0, NULL }, unused_val = { 0, NULL };
+
+ int ret = mdb_cursor_get(cursor, key ? &db_key : &unused_key, &unused_val, op);
+
+ /* LEQ is not supported in LMDB, workaround using GEQ. */
+ if (flags == KNOT_DB_LEQ && key) {
+ /* Searched key is after the last key. */
+ if (ret != MDB_SUCCESS) {
+ return iter_set(iter, NULL, KNOT_DB_LAST);
+ }
+ /* If the searched key != matched, get previous. */
+ if ((key->len != db_key.mv_size) ||
+ (memcmp(key->data, db_key.mv_data, key->len) != 0)) {
+ return iter_set(iter, NULL, KNOT_DB_PREV);
+ }
+ }
+
+ if (ret != MDB_SUCCESS) {
+ mdb_cursor_close(cursor);
+ return NULL;
+ }
+
+ return cursor;
+}
+
+static knot_db_iter_t *iter_begin(knot_db_txn_t *txn, unsigned flags)
+{
+ struct lmdb_env *env = txn->db;
+ MDB_cursor *cursor = NULL;
+
+ int ret = mdb_cursor_open(txn->txn, env->dbi, &cursor);
+ if (ret != MDB_SUCCESS) {
+ return NULL;
+ }
+
+ /* Clear sorted flag, as it's always sorted. */
+ flags &= ~KNOT_DB_SORTED;
+
+ return iter_set(cursor, NULL, (flags == 0) ? KNOT_DB_FIRST : flags);
+}
+
+static knot_db_iter_t *iter_next(knot_db_iter_t *iter)
+{
+ return iter_set(iter, NULL, KNOT_DB_NEXT);
+}
+
+_public_
+int knot_db_lmdb_iter_del(knot_db_iter_t *iter)
+{
+ MDB_cursor *cursor = iter;
+
+ int ret = mdb_cursor_del(cursor, 0);
+ if (ret != MDB_SUCCESS) {
+ return lmdb_error_to_knot(ret);
+ }
+
+ return KNOT_EOK;
+}
+
+static int iter_key(knot_db_iter_t *iter, knot_db_val_t *key)
+{
+ MDB_cursor *cursor = iter;
+
+ MDB_val mdb_key, mdb_val;
+ int ret = mdb_cursor_get(cursor, &mdb_key, &mdb_val, MDB_GET_CURRENT);
+ if (ret != MDB_SUCCESS) {
+ return lmdb_error_to_knot(ret);
+ }
+
+ key->data = mdb_key.mv_data;
+ key->len = mdb_key.mv_size;
+ return KNOT_EOK;
+}
+
+static int iter_val(knot_db_iter_t *iter, knot_db_val_t *val)
+{
+ MDB_cursor *cursor = iter;
+
+ MDB_val mdb_key, mdb_val;
+ int ret = mdb_cursor_get(cursor, &mdb_key, &mdb_val, MDB_GET_CURRENT);
+ if (ret != MDB_SUCCESS) {
+ return lmdb_error_to_knot(ret);
+ }
+
+ val->data = mdb_val.mv_data;
+ val->len = mdb_val.mv_size;
+ return KNOT_EOK;
+}
+
+static void iter_finish(knot_db_iter_t *iter)
+{
+ if (iter == NULL) {
+ return;
+ }
+
+ MDB_cursor *cursor = iter;
+ mdb_cursor_close(cursor);
+}
+
+static int find(knot_db_txn_t *txn, knot_db_val_t *key, knot_db_val_t *val, unsigned flags)
+{
+ knot_db_iter_t *iter = iter_begin(txn, KNOT_DB_NOOP);
+ if (iter == NULL) {
+ return KNOT_ERROR;
+ }
+
+ int ret = KNOT_EOK;
+ if (iter_set(iter, key, flags) == NULL) {
+ return KNOT_ENOENT;
+ } else {
+ ret = iter_val(iter, val);
+ }
+
+ iter_finish(iter);
+ return ret;
+}
+
+static int insert(knot_db_txn_t *txn, knot_db_val_t *key, knot_db_val_t *val, unsigned flags)
+{
+ struct lmdb_env *env = txn->db;
+
+ MDB_val db_key = { key->len, key->data };
+ MDB_val data = { val->len, val->data };
+
+ /* Reserve if only size is declared. */
+ unsigned mdb_flags = 0;
+ if (val->len > 0 && val->data == NULL) {
+ mdb_flags |= MDB_RESERVE;
+ }
+
+ int ret = mdb_put(txn->txn, env->dbi, &db_key, &data, mdb_flags);
+ if (ret != MDB_SUCCESS) {
+ return lmdb_error_to_knot(ret);
+ }
+
+ /* Update the result. */
+ val->data = data.mv_data;
+ val->len = data.mv_size;
+
+ return KNOT_EOK;
+}
+
+static int del(knot_db_txn_t *txn, knot_db_val_t *key)
+{
+ struct lmdb_env *env = txn->db;
+ MDB_val db_key = { key->len, key->data };
+
+ int ret = mdb_del(txn->txn, env->dbi, &db_key, NULL);
+ if (ret != MDB_SUCCESS) {
+ return lmdb_error_to_knot(ret);
+ }
+
+ return KNOT_EOK;
+}
+
+_public_
+int knot_db_lmdb_del_exact(knot_db_txn_t *txn, knot_db_val_t *key, knot_db_val_t *val)
+{
+ struct lmdb_env *env = txn->db;
+ MDB_val db_key = { key->len, key->data };
+ MDB_val data = { val->len, val->data };
+
+ int ret = mdb_del(txn->txn, env->dbi, &db_key, &data);
+ if (ret != MDB_SUCCESS) {
+ return lmdb_error_to_knot(ret);
+ }
+
+ return KNOT_EOK;
+}
+
+_public_
+size_t knot_db_lmdb_get_mapsize(knot_db_t *db)
+{
+ struct lmdb_env *env = db;
+ MDB_envinfo info;
+ if (mdb_env_info(env->env, &info) != MDB_SUCCESS) {
+ return 0;
+ }
+
+ return info.me_mapsize;
+}
+
+// you should SUM all the usages of DBs sharing one mapsize
+_public_
+size_t knot_db_lmdb_get_usage(knot_db_t *db)
+{
+ struct lmdb_env *env = db;
+ knot_db_txn_t txn;
+ knot_db_lmdb_txn_begin(db, &txn, NULL, KNOT_DB_RDONLY);
+ MDB_stat st;
+ if (mdb_stat(txn.txn, env->dbi, &st) != MDB_SUCCESS) {
+ txn_abort(&txn);
+ return 0;
+ }
+ txn_abort(&txn);
+
+ size_t pgs_used = st.ms_branch_pages + st.ms_leaf_pages + st.ms_overflow_pages;
+
+ return (pgs_used * st.ms_psize);
+}
+
+_public_
+const char *knot_db_lmdb_get_path(knot_db_t *db)
+{
+ struct lmdb_env *env = db;
+
+ static const char *path;
+ if (mdb_env_get_path(env->env, &path) == 0) {
+ return path;
+ } else {
+ return "";
+ }
+}
+
+_public_
+const knot_db_api_t *knot_db_lmdb_api(void)
+{
+ static const knot_db_api_t api = {
+ "lmdb",
+ init, deinit,
+ txn_begin, txn_commit, txn_abort,
+ count, clear, find, insert, del,
+ iter_begin, iter_set, iter_next, iter_key, iter_val, iter_finish
+ };
+
+ return &api;
+}
diff --git a/src/libknot/db/db_lmdb.h b/src/libknot/db/db_lmdb.h
new file mode 100644
index 0000000..ef8e664
--- /dev/null
+++ b/src/libknot/db/db_lmdb.h
@@ -0,0 +1,73 @@
+/* Copyright (C) 2019 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+ 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 <https://www.gnu.org/licenses/>.
+ */
+
+/*!
+ * \file
+ *
+ * \addtogroup db
+ * @{
+ */
+
+#pragma once
+
+#include "libknot/db/db.h"
+
+/* Defines. */
+#define KNOT_DB_LMDB_MAPSIZE (100 * 1024 * 1024)
+
+/* LMDB specific flags. */
+extern const unsigned KNOT_DB_LMDB_NOTLS;
+extern const unsigned KNOT_DB_LMDB_RDONLY;
+extern const unsigned KNOT_DB_LMDB_INTEGERKEY;
+extern const unsigned KNOT_DB_LMDB_NOSYNC;
+extern const unsigned KNOT_DB_LMDB_WRITEMAP;
+extern const unsigned KNOT_DB_LMDB_MAPASYNC;
+extern const unsigned KNOT_DB_LMDB_DUPSORT;
+
+/* Native options. */
+struct knot_db_lmdb_opts {
+ const char *path; /*!< Database environment path. */
+ const char *dbname; /*!< Database name (or NULL). */
+ size_t mapsize; /*!< Environment map size. */
+ unsigned maxdbs; /*!< Maximum number of databases in the env. */
+ unsigned maxreaders; /*!< Maximum number of concurrent readers */
+ struct {
+ unsigned env; /*!< Environment flags. */
+ unsigned db; /*!< Database flags. */
+ } flags;
+};
+
+/* Default options. */
+#define KNOT_DB_LMDB_OPTS_INITIALIZER { \
+ NULL, NULL, \
+ KNOT_DB_LMDB_MAPSIZE, \
+ 0, \
+ 126, /* = contrib/lmdb/mdb.c DEFAULT_READERS */ \
+ { 0, 0 } \
+}
+
+const knot_db_api_t *knot_db_lmdb_api(void);
+
+/* LMDB specific operations. */
+int knot_db_lmdb_del_exact(knot_db_txn_t *txn, knot_db_val_t *key, knot_db_val_t *val);
+int knot_db_lmdb_txn_begin(knot_db_t *db, knot_db_txn_t *txn, knot_db_txn_t *parent,
+ unsigned flags);
+int knot_db_lmdb_iter_del(knot_db_iter_t *iter);
+size_t knot_db_lmdb_get_mapsize(knot_db_t *db);
+size_t knot_db_lmdb_get_usage(knot_db_t *db);
+const char *knot_db_lmdb_get_path(knot_db_t *db);
+
+/*! @} */
diff --git a/src/libknot/db/db_trie.c b/src/libknot/db/db_trie.c
new file mode 100644
index 0000000..1bdba8b
--- /dev/null
+++ b/src/libknot/db/db_trie.c
@@ -0,0 +1,176 @@
+/* Copyright (C) 2021 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+ 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 <https://www.gnu.org/licenses/>.
+ */
+
+#include <assert.h>
+
+#include "libknot/attribute.h"
+#include "libknot/errcode.h"
+#include "libknot/db/db_trie.h"
+#include "contrib/qp-trie/trie.h"
+#include "contrib/mempattern.h"
+
+static int init(knot_db_t **db, knot_mm_t *mm, void *arg)
+{
+ if (db == NULL || arg == NULL) {
+ return KNOT_EINVAL;
+ }
+
+ _unused_ struct knot_db_trie_opts *opts = arg;
+ trie_t *trie = trie_create(mm);
+ if (!trie) {
+ return KNOT_ENOMEM;
+ }
+
+ *db = trie;
+
+ return KNOT_EOK;
+}
+
+static void deinit(knot_db_t *db)
+{
+ trie_free((trie_t *)db);
+}
+
+static int txn_begin(knot_db_t *db, knot_db_txn_t *txn, unsigned flags)
+{
+ txn->txn = (void *)(size_t)flags;
+ txn->db = db;
+ return KNOT_EOK; /* N/A */
+}
+
+static int txn_commit(knot_db_txn_t *txn)
+{
+ return KNOT_EOK;
+}
+
+static void txn_abort(knot_db_txn_t *txn)
+{
+}
+
+static int count(knot_db_txn_t *txn)
+{
+ return trie_weight((trie_t *)txn->db);
+}
+
+static int clear(knot_db_txn_t *txn)
+{
+ trie_clear((trie_t *)txn->db);
+
+ return KNOT_EOK;
+}
+
+static int find(knot_db_txn_t *txn, knot_db_val_t *key, knot_db_val_t *val, unsigned flags)
+{
+ trie_val_t *ret = trie_get_try((trie_t *)txn->db, key->data, key->len);
+ if (ret == NULL) {
+ return KNOT_ENOENT;
+ }
+
+ val->data = *ret;
+ val->len = sizeof(trie_val_t); /* Trie doesn't support storing length. */
+ return KNOT_EOK;
+}
+
+static int insert(knot_db_txn_t *txn, knot_db_val_t *key, knot_db_val_t *val, unsigned flags)
+{
+ /* No flags supported. */
+ if (flags != 0) {
+ return KNOT_ENOTSUP;
+ }
+
+ trie_val_t *ret = trie_get_ins((trie_t *)txn->db, key->data, key->len);
+ if (ret == NULL) {
+ return KNOT_ENOMEM;
+ }
+
+ *ret = val->data;
+ return KNOT_EOK;
+}
+
+static int del(knot_db_txn_t *txn, knot_db_val_t *key)
+{
+ return trie_del((trie_t *)txn->db, key->data, key->len, NULL);
+}
+
+static knot_db_iter_t *iter_begin(knot_db_txn_t *txn, unsigned flags)
+{
+ flags &= ~KNOT_DB_SORTED;
+
+ /* No operations other than begin are supported right now. */
+ if (flags != 0) {
+ return NULL;
+ }
+
+ return trie_it_begin((trie_t *)txn->db);
+}
+
+static knot_db_iter_t *iter_seek(knot_db_iter_t *iter, knot_db_val_t *key, unsigned flags)
+{
+ assert(0);
+ return NULL; /* ENOTSUP */
+}
+
+static knot_db_iter_t *iter_next(knot_db_iter_t *iter)
+{
+ trie_it_next((trie_it_t *)iter);
+ if (trie_it_finished((trie_it_t *)iter)) {
+ trie_it_free((trie_it_t *)iter);
+ return NULL;
+ }
+
+ return iter;
+}
+
+static int iter_key(knot_db_iter_t *iter, knot_db_val_t *val)
+{
+ val->data = (void *)trie_it_key((trie_it_t *)iter, &val->len);
+ if (val->data == NULL) {
+ return KNOT_ENOENT;
+ }
+
+ return KNOT_EOK;
+}
+
+static int iter_val(knot_db_iter_t *iter, knot_db_val_t *val)
+{
+ trie_val_t *ret = trie_it_val((trie_it_t *)iter);
+ if (ret == NULL) {
+ return KNOT_ENOENT;
+ }
+
+ val->data = *ret;
+ val->len = sizeof(trie_val_t);
+ return KNOT_EOK;
+}
+
+static void iter_finish(knot_db_iter_t *iter)
+{
+ trie_it_free((trie_it_t *)iter);
+}
+
+_public_
+const knot_db_api_t *knot_db_trie_api(void)
+{
+ static const knot_db_api_t api = {
+ "trie",
+ init, deinit,
+ txn_begin, txn_commit, txn_abort,
+ count, clear, find, insert, del,
+ iter_begin, iter_seek, iter_next, iter_key, iter_val, iter_finish
+ };
+
+ return &api;
+}
diff --git a/src/libknot/db/db_trie.h b/src/libknot/db/db_trie.h
new file mode 100644
index 0000000..fee4722
--- /dev/null
+++ b/src/libknot/db/db_trie.h
@@ -0,0 +1,40 @@
+/* Copyright (C) 2017 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+ 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 <https://www.gnu.org/licenses/>.
+ */
+
+/*!
+ * \file
+ *
+ * \addtogroup db
+ * @{
+ */
+
+#pragma once
+
+#include "libknot/db/db.h"
+
+/* Native options. */
+struct knot_db_trie_opts {
+ unsigned unused;
+};
+
+/* Default options. */
+#define KNOT_DB_TRIE_OPTS_INITIALIZER { \
+ 0 \
+}
+
+const knot_db_api_t *knot_db_trie_api(void);
+
+/*! @} */