1 // Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
2 // This source code is licensed under both the GPLv2 (found in the
3 // COPYING file in the root directory) and Apache 2.0 License
4 // (found in the LICENSE.Apache file in the root directory).
5
6 #include <stdio.h>
7 #include <string.h>
8 #include <stdlib.h>
9 #include <assert.h>
10
11 #include "rocksdb/c.h"
12
13 #include <unistd.h> // sysconf() - get CPU count
14
15 const char DBPath[] = "/tmp/rocksdb_simple_example";
16 const char DBBackupPath[] = "/tmp/rocksdb_simple_example_backup";
17
main(int argc,char ** argv)18 int main(int argc, char **argv) {
19 rocksdb_t *db;
20 rocksdb_backup_engine_t *be;
21 rocksdb_options_t *options = rocksdb_options_create();
22 // Optimize RocksDB. This is the easiest way to
23 // get RocksDB to perform well
24 long cpus = sysconf(_SC_NPROCESSORS_ONLN); // get # of online cores
25 rocksdb_options_increase_parallelism(options, (int)(cpus));
26 rocksdb_options_optimize_level_style_compaction(options, 0);
27 // create the DB if it's not already present
28 rocksdb_options_set_create_if_missing(options, 1);
29
30 // open DB
31 char *err = NULL;
32 db = rocksdb_open(options, DBPath, &err);
33 assert(!err);
34
35 // open Backup Engine that we will use for backing up our database
36 be = rocksdb_backup_engine_open(options, DBBackupPath, &err);
37 assert(!err);
38
39 // Put key-value
40 rocksdb_writeoptions_t *writeoptions = rocksdb_writeoptions_create();
41 const char key[] = "key";
42 const char *value = "value";
43 rocksdb_put(db, writeoptions, key, strlen(key), value, strlen(value) + 1,
44 &err);
45 assert(!err);
46 // Get value
47 rocksdb_readoptions_t *readoptions = rocksdb_readoptions_create();
48 size_t len;
49 char *returned_value =
50 rocksdb_get(db, readoptions, key, strlen(key), &len, &err);
51 assert(!err);
52 assert(strcmp(returned_value, "value") == 0);
53 free(returned_value);
54
55 // create new backup in a directory specified by DBBackupPath
56 rocksdb_backup_engine_create_new_backup(be, db, &err);
57 assert(!err);
58
59 rocksdb_close(db);
60
61 // If something is wrong, you might want to restore data from last backup
62 rocksdb_restore_options_t *restore_options = rocksdb_restore_options_create();
63 rocksdb_backup_engine_restore_db_from_latest_backup(be, DBPath, DBPath,
64 restore_options, &err);
65 assert(!err);
66 rocksdb_restore_options_destroy(restore_options);
67
68 db = rocksdb_open(options, DBPath, &err);
69 assert(!err);
70
71 // cleanup
72 rocksdb_writeoptions_destroy(writeoptions);
73 rocksdb_readoptions_destroy(readoptions);
74 rocksdb_options_destroy(options);
75 rocksdb_backup_engine_close(be);
76 rocksdb_close(db);
77
78 return 0;
79 }
80