RoaringBitmap数据结构的Go移植
jopen
10年前
Roaring bitmap数据结构的一个Go语言移植，Java版本可以查看：http://www.open-open.com/lib/view/open1419558335250.html。
Java 和 Go 两个版本的二进制相兼容，因此用Java程序保存的bitmaps，可以用Go加载，反之亦然。
依赖
- go get github.com/smartystreets/goconvey/convey
- go get github.com/willf/bitset
Naturally, you also need to grab the roaring code itself:
- go get github.com/tgruben/roaring
示例
Here is a simplified but complete example:
package main import ( "fmt" "github.com/tgruben/roaring" "bytes" ) func main() { // example inspired by https://github.com/fzandona/goroa 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.NewRoaringBitmap() 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) // 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:= NewRoaringBitmap() newrb.ReadFrom(buf) if rb1.Equals(newrb) { fmt.Println("I wrote the content to a byte stream and read it back.") } }