rdb-rs - fast and efficient RDB parsing utility

Introduction

Redis is an open source, BSD licensed, advanced key-value cache and store. It is often referred to as a data structure server since keys can contain strings, hashes, lists, sets, sorted sets, bitmaps and hyperloglogs.

Redis’ RDB file is a binary representation of the in-memory store. This binary file is sufficient to completely restore Redis’ state.

Optimizing for fast read/writes means the on-disk format should be as close as possible to the in-memory representation. This is the approach taken by the RDB file. As a consequence, you cannot parse the RDB file without some understanding of Redis’ in-memory representation of data structures.

rdb-rs is a library and tool to parse RDB and dump it into another format like JSON or the Redis protocol.

It is based on Sripathi Krishnan's redis-rdb-tools and compatible with the latest Redis RDB version 7.

Getting started

rdb-rs is offered both as a library and as a stand-alone command line tool.

Command-line tool

The command line tool can be used to dump an existing RDB file in one of the provided formats:

rdb --format json dump.rdb
# [{"key":"value"}]
rdb --format protocol dump.rdb
# *2
# $6
# SELECT
# $1
# 0
# *3
# $3
# SET
# $3
# key
# $5
# value

See the help output for more info how to use it:

rdb --help
# Usage: target/rdb [options] dump.rdb
#
# Options:
#     -f --format FORMAT  Format to output. Valid: json, plain, nil, protocol
#     -k --keys KEYS      Keys to show. Can be a regular expression
#     -d --databases DB   Database to show
#     -t --type TYPE      Type to show
#     -h --help           print this help menu

Library

Using the library is as easy as calling the rdb::parse function and pass it a stream to read from and a formatter to use.

use std::old_io::{BufferedReader, File};

let file = File::open(&Path::new("dump.rdb"));
let reader = BufferedReader::new(file);
rdb::parse(reader, rdb::formatter::JSON::new(), rdb::filter::Simple::new());

rdb-rs brings 4 pre-defined formatters, which can be used:

Plain: Just plain output for testing
JSON: JSON-encoded output
Nil: Surpresses all output
Protocol: Formats the data in RESP, the Redis Serialization Protocol

It's easy to build your own formatter. All you need to do is implementing the Formatter trait.

Code

The code is available on GitHub: github.com/badboy/rdb-rs.
Submit bugs, requests and improvements to the issue tracker. You can also contact me via or twitter.

Documentation

The included documentation of the RDB format is largely based on RDB_File_Format.textile and RDB_Version_History.textile. Thanks to Sripathi Krishnan and his work on the redis-rdb-tools.

Crate documentation

The full code documentation is available online.

rdb-rs

RDB documentation