d77176912b
* Migrate to go modules * make vendor * Update mvdan.cc/xurls * make vendor * Update code.gitea.io/git * make fmt-check * Update github.com/go-sql-driver/mysql * make vendor
246 lines
8.2 KiB
Markdown
246 lines
8.2 KiB
Markdown
roaring [](https://travis-ci.org/RoaringBitmap/roaring) [](https://coveralls.io/github/RoaringBitmap/roaring?branch=master) [](https://godoc.org/github.com/RoaringBitmap/roaring) [](https://goreportcard.com/report/github.com/RoaringBitmap/roaring)
|
|
=============
|
|
|
|
This is a go version of the Roaring bitmap data structure.
|
|
|
|
|
|
|
|
Roaring bitmaps are used by several major systems such as [Apache Lucene][lucene] and derivative systems such as [Solr][solr] and
|
|
[Elasticsearch][elasticsearch], [Metamarkets' Druid][druid], [LinkedIn Pinot][pinot], [Netflix Atlas][atlas], [Apache Spark][spark], [OpenSearchServer][opensearchserver], [Cloud Torrent][cloudtorrent], [Whoosh][whoosh], [Pilosa][pilosa], [Microsoft Visual Studio Team Services (VSTS)][vsts], and eBay's [Apache Kylin][kylin].
|
|
|
|
[lucene]: https://lucene.apache.org/
|
|
[solr]: https://lucene.apache.org/solr/
|
|
[elasticsearch]: https://www.elastic.co/products/elasticsearch
|
|
[druid]: http://druid.io/
|
|
[spark]: https://spark.apache.org/
|
|
[opensearchserver]: http://www.opensearchserver.com
|
|
[cloudtorrent]: https://github.com/jpillora/cloud-torrent
|
|
[whoosh]: https://bitbucket.org/mchaput/whoosh/wiki/Home
|
|
[pilosa]: https://www.pilosa.com/
|
|
[kylin]: http://kylin.apache.org/
|
|
[pinot]: http://github.com/linkedin/pinot/wiki
|
|
[vsts]: https://www.visualstudio.com/team-services/
|
|
[atlas]: https://github.com/Netflix/atlas
|
|
|
|
Roaring bitmaps are found to work well in many important applications:
|
|
|
|
> Use Roaring for bitmap compression whenever possible. Do not use other bitmap compression methods ([Wang et al., SIGMOD 2017](http://db.ucsd.edu/wp-content/uploads/2017/03/sidm338-wangA.pdf))
|
|
|
|
|
|
The ``roaring`` Go library is used by
|
|
* [Cloud Torrent](https://github.com/jpillora/cloud-torrent): a self-hosted remote torrent client
|
|
* [runv](https://github.com/hyperhq/runv): an Hypervisor-based runtime for the Open Containers Initiative
|
|
* [InfluxDB](https://www.influxdata.com)
|
|
* [Pilosa](https://www.pilosa.com/)
|
|
* [Bleve](http://www.blevesearch.com)
|
|
|
|
This library is used in production in several systems, it is part of the [Awesome Go collection](https://awesome-go.com).
|
|
|
|
|
|
There are also [Java](https://github.com/RoaringBitmap/RoaringBitmap) and [C/C++](https://github.com/RoaringBitmap/CRoaring) versions. The Java, C, C++ and Go version are binary compatible: e.g, you can save bitmaps
|
|
from a Java program and load them back in Go, and vice versa. We have a [format specification](https://github.com/RoaringBitmap/RoaringFormatSpec).
|
|
|
|
|
|
This code is licensed under Apache License, Version 2.0 (ASL2.0).
|
|
|
|
Copyright 2016-... by the authors.
|
|
|
|
|
|
### References
|
|
|
|
- Daniel Lemire, Owen Kaser, Nathan Kurz, Luca Deri, Chris O'Hara, François Saint-Jacques, Gregory Ssi-Yan-Kai, Roaring Bitmaps: Implementation of an Optimized Software Library, Software: Practice and Experience 48 (4), 2018 [arXiv:1709.07821](https://arxiv.org/abs/1709.07821)
|
|
- Samy Chambi, Daniel Lemire, Owen Kaser, Robert Godin,
|
|
Better bitmap performance with Roaring bitmaps,
|
|
Software: Practice and Experience 46 (5), 2016.
|
|
http://arxiv.org/abs/1402.6407 This paper used data from http://lemire.me/data/realroaring2014.html
|
|
- Daniel Lemire, Gregory Ssi-Yan-Kai, Owen Kaser, Consistently faster and smaller compressed bitmaps with Roaring, Software: Practice and Experience 46 (11), 2016. http://arxiv.org/abs/1603.06549
|
|
|
|
|
|
### Dependencies
|
|
|
|
Dependencies are fetched automatically by giving the `-t` flag to `go get`.
|
|
|
|
they include
|
|
- github.com/smartystreets/goconvey/convey
|
|
- github.com/willf/bitset
|
|
- github.com/mschoch/smat
|
|
- github.com/glycerine/go-unsnap-stream
|
|
- github.com/philhofer/fwd
|
|
- github.com/jtolds/gls
|
|
|
|
Note that the smat library requires Go 1.6 or better.
|
|
|
|
#### Installation
|
|
|
|
- go get -t github.com/RoaringBitmap/roaring
|
|
|
|
|
|
### Example
|
|
|
|
Here is a simplified but complete example:
|
|
|
|
```go
|
|
package main
|
|
|
|
import (
|
|
"fmt"
|
|
"github.com/RoaringBitmap/roaring"
|
|
"bytes"
|
|
)
|
|
|
|
|
|
func main() {
|
|
// example inspired by https://github.com/fzandona/goroar
|
|
fmt.Println("==roaring==")
|
|
rb1 := roaring.BitmapOf(1, 2, 3, 4, 5, 100, 1000)
|
|
fmt.Println(rb1.String())
|
|
|
|
rb2 := roaring.BitmapOf(3, 4, 1000)
|
|
fmt.Println(rb2.String())
|
|
|
|
rb3 := roaring.New()
|
|
fmt.Println(rb3.String())
|
|
|
|
fmt.Println("Cardinality: ", rb1.GetCardinality())
|
|
|
|
fmt.Println("Contains 3? ", rb1.Contains(3))
|
|
|
|
rb1.And(rb2)
|
|
|
|
rb3.Add(1)
|
|
rb3.Add(5)
|
|
|
|
rb3.Or(rb1)
|
|
|
|
// computes union of the three bitmaps in parallel using 4 workers
|
|
roaring.ParOr(4, rb1, rb2, rb3)
|
|
// computes intersection of the three bitmaps in parallel using 4 workers
|
|
roaring.ParAnd(4, rb1, rb2, rb3)
|
|
|
|
|
|
// prints 1, 3, 4, 5, 1000
|
|
i := rb3.Iterator()
|
|
for i.HasNext() {
|
|
fmt.Println(i.Next())
|
|
}
|
|
fmt.Println()
|
|
|
|
// next we include an example of serialization
|
|
buf := new(bytes.Buffer)
|
|
rb1.WriteTo(buf) // we omit error handling
|
|
newrb:= roaring.New()
|
|
newrb.ReadFrom(buf)
|
|
if rb1.Equals(newrb) {
|
|
fmt.Println("I wrote the content to a byte stream and read it back.")
|
|
}
|
|
}
|
|
```
|
|
|
|
If you wish to use serialization and handle errors, you might want to
|
|
consider the following sample of code:
|
|
|
|
```go
|
|
rb := BitmapOf(1, 2, 3, 4, 5, 100, 1000)
|
|
buf := new(bytes.Buffer)
|
|
size,err:=rb.WriteTo(buf)
|
|
if err != nil {
|
|
t.Errorf("Failed writing")
|
|
}
|
|
newrb:= New()
|
|
size,err=newrb.ReadFrom(buf)
|
|
if err != nil {
|
|
t.Errorf("Failed reading")
|
|
}
|
|
if ! rb.Equals(newrb) {
|
|
t.Errorf("Cannot retrieve serialized version")
|
|
}
|
|
```
|
|
|
|
Given N integers in [0,x), then the serialized size in bytes of
|
|
a Roaring bitmap should never exceed this bound:
|
|
|
|
`` 8 + 9 * ((long)x+65535)/65536 + 2 * N ``
|
|
|
|
That is, given a fixed overhead for the universe size (x), Roaring
|
|
bitmaps never use more than 2 bytes per integer. You can call
|
|
``BoundSerializedSizeInBytes`` for a more precise estimate.
|
|
|
|
|
|
### Documentation
|
|
|
|
Current documentation is available at http://godoc.org/github.com/RoaringBitmap/roaring
|
|
|
|
### Goroutine safety
|
|
|
|
In general, it should not generally be considered safe to access
|
|
the same bitmaps using different goroutines--they are left
|
|
unsynchronized for performance. Should you want to access
|
|
a Bitmap from more than one goroutine, you should
|
|
provide synchronization. Typically this is done by using channels to pass
|
|
the *Bitmap around (in Go style; so there is only ever one owner),
|
|
or by using `sync.Mutex` to serialize operations on Bitmaps.
|
|
|
|
### Coverage
|
|
|
|
We test our software. For a report on our test coverage, see
|
|
|
|
https://coveralls.io/github/RoaringBitmap/roaring?branch=master
|
|
|
|
### Benchmark
|
|
|
|
Type
|
|
|
|
go test -bench Benchmark -run -
|
|
|
|
To run benchmarks on [Real Roaring Datasets](https://github.com/RoaringBitmap/real-roaring-datasets)
|
|
run the following:
|
|
|
|
```sh
|
|
go get github.com/RoaringBitmap/real-roaring-datasets
|
|
BENCH_REAL_DATA=1 go test -bench BenchmarkRealData -run -
|
|
```
|
|
|
|
### Iterative use
|
|
|
|
You can use roaring with gore:
|
|
|
|
- go get -u github.com/motemen/gore
|
|
- Make sure that ``$GOPATH/bin`` is in your ``$PATH``.
|
|
- go get github/RoaringBitmap/roaring
|
|
|
|
```go
|
|
$ gore
|
|
gore version 0.2.6 :help for help
|
|
gore> :import github.com/RoaringBitmap/roaring
|
|
gore> x:=roaring.New()
|
|
gore> x.Add(1)
|
|
gore> x.String()
|
|
"{1}"
|
|
```
|
|
|
|
|
|
### Fuzzy testing
|
|
|
|
You can help us test further the library with fuzzy testing:
|
|
|
|
go get github.com/dvyukov/go-fuzz/go-fuzz
|
|
go get github.com/dvyukov/go-fuzz/go-fuzz-build
|
|
go test -tags=gofuzz -run=TestGenerateSmatCorpus
|
|
go-fuzz-build github.com/RoaringBitmap/roaring
|
|
go-fuzz -bin=./roaring-fuzz.zip -workdir=workdir/ -timeout=200
|
|
|
|
Let it run, and if the # of crashers is > 0, check out the reports in
|
|
the workdir where you should be able to find the panic goroutine stack
|
|
traces.
|
|
|
|
### Alternative in Go
|
|
|
|
There is a Go version wrapping the C/C++ implementation https://github.com/RoaringBitmap/gocroaring
|
|
|
|
For an alternative implementation in Go, see https://github.com/fzandona/goroar
|
|
The two versions were written independently.
|
|
|
|
|
|
### Mailing list/discussion group
|
|
|
|
https://groups.google.com/forum/#!forum/roaring-bitmaps
|