rust-rocksdb/README.md

rust-rocksdb

rust-rocksdb has been tested with version 3.8.1 on linux and OSX. Crate version 0.0.3 should work on the 1.0.0 alpha.

Prerequisites

wget https://github.com/facebook/rocksdb/archive/rocksdb-3.8.tar.gz
tar xvf rocksdb-3.8.tar.gz && cd rocksdb-rocksdb-3.8 && make static_lib

From here, you probably want to sudo make install to copy the library to the system library directory. If you don't want to, or cannot due to your system's security policy, there are many other ways to load a library. One quick and dirty method that may work on linux and OSX is to invoke your code from your project's root directory like so: LD_PRELOAD=/path/to/librocksdb.a cargo run

Running

Cargo.toml

[dependencies]
rocksdb = "~0.0.3"

Code

extern crate rocksdb;
use rocksdb::RocksDB;

fn main() {
    let db = RocksDB::open_default("/path/for/rocksdb/storage").unwrap();
    db.put(b"my key", b"my value");
    db.get(b"my key")
        .map( |value| { 
            println!("retrieved value {}", value.to_utf8().unwrap())
        })
        .on_absent( || { println!("value not found") })
        .on_error( |e| { println!("operational problem encountered: {}", e) });

    db.delete(b"my key");
    db.close();
}

Rustic Merge Operator

extern crate rocksdb;
use rocksdb::{RocksDBOptions, RocksDB, MergeOperands};

fn concat_merge(new_key: &[u8], existing_val: Option<&[u8]>,
    mut operands: &mut MergeOperands) -> Vec<u8> {
    let mut result: Vec<u8> = Vec::with_capacity(operands.size_hint().val0());
    match existing_val {
        Some(v) => result.push_all(v),
        None => (),
    }
    for op in operands {
        result.push_all(op);
    }
    result
}

fn main() {
    let path = "/path/to/rocksdb";
    let opts = RocksDBOptions::new();
    opts.create_if_missing(true);
    opts.add_merge_operator("test operator", concat_merge);
    let db = RocksDB::open(opts, path).unwrap();
    let p = db.put(b"k1", b"a");
    db.merge(b"k1", b"b");
    db.merge(b"k1", b"c");
    db.merge(b"k1", b"d");
    db.merge(b"k1", b"efg");
    let r = db.get(b"k1");
    assert!(r.unwrap().to_utf8().unwrap() == "abcdefg");
    db.close();
}

Apply Some Tunings

Please read the official tuning guide, and most importantly, measure performance under realistic workloads with realistic hardware.

use rocksdb::{RocksDBOptions, RocksDB, new_bloom_filter};
use rocksdb::RocksDBCompactionStyle::RocksDBUniversalCompaction;

fn tuned_for_somebody_elses_disk() -> RocksDB {
    let path = "_rust_rocksdb_optimizetest";
    let opts = RocksDBOptions::new();
    opts.create_if_missing(true);
    opts.set_block_size(524288);
    opts.set_max_open_files(10000);
    opts.set_use_fsync(false);
    opts.set_bytes_per_sync(8388608);
    opts.set_disable_data_sync(false);
    opts.set_block_cache_size_mb(1024);
    opts.set_table_cache_num_shard_bits(6);
    opts.set_max_write_buffer_number(32);
    opts.set_write_buffer_size(536870912);
    opts.set_target_file_size_base(1073741824);
    opts.set_min_write_buffer_number_to_merge(4);
    opts.set_level_zero_stop_writes_trigger(2000);
    opts.set_level_zero_slowdown_writes_trigger(0);
    opts.set_compaction_style(RocksDBUniversalCompaction);
    opts.set_max_background_compactions(4);
    opts.set_max_background_flushes(4);
    opts.set_filter_deletes(false);
    opts.set_disable_auto_compactions(true);

    let filter = new_bloom_filter(10);
    opts.set_filter(filter);

    RocksDB::open(opts, path).unwrap()
}

status

• basic open/put/get/delete/close
• linux support
• rocksdb compiled via cargo
• OSX support
• rustic merge operator
• compaction filter, style
• LRU cache
• destroy/repair
• batch
• iterator
• range
• create/release snapshot
• column family operations
• comparator
• slicetransform
• windows support

Feedback and pull requests welcome!