redis-roaring

Roaring Bitmaps for Redis

Intro

This project uses the CRoaring library to implement roaring bitmap commands for Redis. These commands can have the same performance as redis' native bitmaps for O(1) operations and be up to 8x faster for O(N) calls, according to microbenchmarks, while consuming less memory than their uncompressed counterparts (benchmark pending).

Pull requests are welcome.

Dependencies

• CRoaring (bitmap compression library used by this redis module)
• cmake (build tools needed for compiling the source code)
• redis (server needed for integration tests)
• hiredis (redis client library needed for performance tests)

Getting started

$ git clone https://github.com/aviggiano/redis-roaring.git
$ cd redis-roaring/
$ configure.sh
$ cd dist 
$ ./redis-server ./redis.conf  

then you can open another terminal and use ./redis-cli to connect to the redis server

Docker

It is also possible to run this project as a docker container:

docker build -t redis-roaring
docker run -p 6379:6379 redis-roaring:latest

Tests

Run the test.sh script for unit tests, integration tests and performance tests. The performance tests can take a while, since they run on a real dataset of integer values.

API

Currently the following operations are supported

• R.SETBIT (same as SETBIT)
• R.GETBIT (same as GETBIT)
• R.BITOP (same as BITOP)
• R.BITCOUNT (same as BITCOUNT without start and end parameters)
• R.BITPOS (same as BITPOS without start and end parameters)
• R.SETINTARRAY (create a roaring bitmap from an integer array)
• R.GETINTARRAY (get an integer array from a roaring bitmap)
• R.SETBITARRAY (create a roaring bitmap from a bit array string)
• R.GETBITARRAY (get a bit array string from a roaring bitmap)

new added API

• R.APPENDINTARRAY (append integers to a roaring bitmap)
• R.RANGEINTARRAY (get an integer array from a roaring bitmap with start and end, so can implements paging)
• R.SETRANGE (set or append integer range to a roaring bitmap)
• R.SETFULL (fill up a roaring bitmap in integer)
• R.STAT (get statistical information of a roaring bitmap)
• R.OPTIMIZE (optimize a roaring bitmap)

Missing commands:

• R.BITFIELD (same as BITFIELD)

API Example

$ redis-cli
# add numbers from 1 util 100 to test roaring bitmap
127.0.0.1:6379> R.SETRANGE test 1 100
# if the key `test` exists and is a roaring bitmap type, append these numbers
# if the key `test` does not exist, add to a new roaring bitmap

# get all the int numbers
127.0.0.1:6379> R.GETINTARRAY test

# fill up the roaring bitmap, then don't use `R.GETINTARRAY` 
# because you need 2^32*4 bytes memory and a very long time
127.0.0.1:6379> R.SETFULL test

# but you can use `R.RANGEINTARRAY` to get numbers from 100 to 1000 
127.0.0.1:6379> R.RANGEINTARRAY test 100 1000

# you can append numbers to an existing roaring bitmap
127.0.0.1:6379> R.APPENDINTARRAY test 111 222 3333 456 999999999 9999990

Performance

Tested using CRoaring's census1881 dataset on the travis build 427489820:

OP	TIME/OP (us)	ST.DEV. (us)
R.SETBIT	31.89	28.49
SETBIT	29.98	29.23
R.GETBIT	29.91	14.60
GETBIT	28.63	14.58
R.BITCOUNT	32.13	0.10
BITCOUNT	192.38	0.96
R.BITPOS	70.27	0.14
BITPOS	87.70	0.62
R.BITOP NOT	156.66	3.15
BITOP NOT	364.46	5.62
R.BITOP AND	81.56	0.48
BITOP AND	492.97	8.32
R.BITOP OR	107.03	2.44
BITOP OR	461.68	8.42
R.BITOP XOR	69.07	2.82
BITOP XOR	440.75	7.90