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Diffstat (limited to 'src/rocksdb/examples/c_simple_example.c')
-rw-r--r-- | src/rocksdb/examples/c_simple_example.c | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/src/rocksdb/examples/c_simple_example.c b/src/rocksdb/examples/c_simple_example.c new file mode 100644 index 000000000..5564361d1 --- /dev/null +++ b/src/rocksdb/examples/c_simple_example.c @@ -0,0 +1,79 @@ +// Copyright (c) 2011-present, Facebook, Inc. All rights reserved. +// This source code is licensed under both the GPLv2 (found in the +// COPYING file in the root directory) and Apache 2.0 License +// (found in the LICENSE.Apache file in the root directory). + +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <assert.h> + +#include "rocksdb/c.h" + +#include <unistd.h> // sysconf() - get CPU count + +const char DBPath[] = "/tmp/rocksdb_simple_example"; +const char DBBackupPath[] = "/tmp/rocksdb_simple_example_backup"; + +int main(int argc, char **argv) { + rocksdb_t *db; + rocksdb_backup_engine_t *be; + rocksdb_options_t *options = rocksdb_options_create(); + // Optimize RocksDB. This is the easiest way to + // get RocksDB to perform well + long cpus = sysconf(_SC_NPROCESSORS_ONLN); // get # of online cores + rocksdb_options_increase_parallelism(options, (int)(cpus)); + rocksdb_options_optimize_level_style_compaction(options, 0); + // create the DB if it's not already present + rocksdb_options_set_create_if_missing(options, 1); + + // open DB + char *err = NULL; + db = rocksdb_open(options, DBPath, &err); + assert(!err); + + // open Backup Engine that we will use for backing up our database + be = rocksdb_backup_engine_open(options, DBBackupPath, &err); + assert(!err); + + // Put key-value + rocksdb_writeoptions_t *writeoptions = rocksdb_writeoptions_create(); + const char key[] = "key"; + const char *value = "value"; + rocksdb_put(db, writeoptions, key, strlen(key), value, strlen(value) + 1, + &err); + assert(!err); + // Get value + rocksdb_readoptions_t *readoptions = rocksdb_readoptions_create(); + size_t len; + char *returned_value = + rocksdb_get(db, readoptions, key, strlen(key), &len, &err); + assert(!err); + assert(strcmp(returned_value, "value") == 0); + free(returned_value); + + // create new backup in a directory specified by DBBackupPath + rocksdb_backup_engine_create_new_backup(be, db, &err); + assert(!err); + + rocksdb_close(db); + + // If something is wrong, you might want to restore data from last backup + rocksdb_restore_options_t *restore_options = rocksdb_restore_options_create(); + rocksdb_backup_engine_restore_db_from_latest_backup(be, DBPath, DBPath, + restore_options, &err); + assert(!err); + rocksdb_restore_options_destroy(restore_options); + + db = rocksdb_open(options, DBPath, &err); + assert(!err); + + // cleanup + rocksdb_writeoptions_destroy(writeoptions); + rocksdb_readoptions_destroy(readoptions); + rocksdb_options_destroy(options); + rocksdb_backup_engine_close(be); + rocksdb_close(db); + + return 0; +} |