mirror of https://github.com/facebook/rocksdb.git
80 lines
2.6 KiB
C
80 lines
2.6 KiB
C
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
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// This source code is licensed under both the GPLv2 (found in the
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// COPYING file in the root directory) and Apache 2.0 License
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// (found in the LICENSE.Apache file in the root directory).
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#include <stdio.h>
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#include <string.h>
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#include <stdlib.h>
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#include <assert.h>
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#include "rocksdb/c.h"
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#include <unistd.h> // sysconf() - get CPU count
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const char DBPath[] = "/tmp/rocksdb_simple_example";
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const char DBBackupPath[] = "/tmp/rocksdb_simple_example_backup";
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int main(int argc, char **argv) {
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rocksdb_t *db;
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rocksdb_backup_engine_t *be;
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rocksdb_options_t *options = rocksdb_options_create();
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// Optimize RocksDB. This is the easiest way to
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// get RocksDB to perform well
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long cpus = sysconf(_SC_NPROCESSORS_ONLN); // get # of online cores
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rocksdb_options_increase_parallelism(options, (int)(cpus));
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rocksdb_options_optimize_level_style_compaction(options, 0);
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// create the DB if it's not already present
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rocksdb_options_set_create_if_missing(options, 1);
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// open DB
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char *err = NULL;
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db = rocksdb_open(options, DBPath, &err);
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assert(!err);
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// open Backup Engine that we will use for backing up our database
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be = rocksdb_backup_engine_open(options, DBBackupPath, &err);
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assert(!err);
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// Put key-value
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rocksdb_writeoptions_t *writeoptions = rocksdb_writeoptions_create();
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const char key[] = "key";
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const char *value = "value";
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rocksdb_put(db, writeoptions, key, strlen(key), value, strlen(value) + 1,
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&err);
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assert(!err);
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// Get value
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rocksdb_readoptions_t *readoptions = rocksdb_readoptions_create();
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size_t len;
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char *returned_value =
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rocksdb_get(db, readoptions, key, strlen(key), &len, &err);
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assert(!err);
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assert(strcmp(returned_value, "value") == 0);
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free(returned_value);
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// create new backup in a directory specified by DBBackupPath
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rocksdb_backup_engine_create_new_backup(be, db, &err);
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assert(!err);
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rocksdb_close(db);
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// If something is wrong, you might want to restore data from last backup
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rocksdb_restore_options_t *restore_options = rocksdb_restore_options_create();
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rocksdb_backup_engine_restore_db_from_latest_backup(be, DBPath, DBPath,
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restore_options, &err);
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assert(!err);
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rocksdb_restore_options_destroy(restore_options);
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db = rocksdb_open(options, DBPath, &err);
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assert(!err);
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// cleanup
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rocksdb_writeoptions_destroy(writeoptions);
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rocksdb_readoptions_destroy(readoptions);
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rocksdb_options_destroy(options);
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rocksdb_backup_engine_close(be);
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rocksdb_close(db);
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return 0;
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}
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