Description
Package slowpoke is a simple key/value store written using Go's standard library only. Keys are stored in memory (with persistence), values stored on disk.
Description on russian: https://habr.com/post/354224/
Motivation
Replace Bolt with a simpler and more efficient engine.
Slowpoke (from version 2.0) based on pudge
How it works
Keys are stored in memory with persistence to disk. Values stored on disk only.
Slowpoke is parallel
Server
GRPC Server example: okdb
Complex examples
zen platform for authors and their subscribers with a minimalistic design and user-friendly interface.
golang-gin-realworld-example-app
This codebase was created to demonstrate a fully fledged fullstack application built with Golang/Gin/Slowpoke including CRUD operations, authentication, routing, pagination, and more.
Basic example
package main import ( "fmt""github.com/recoilme/slowpoke" ) funcmain(){// create databasefile:="test/example.db"// close all opened databasedeferslowpoke.CloseAll() // init key/valkey:= []byte("foo") val:= []byte("bar") //storeslowpoke.Set(file, key, val) // getres, _:=slowpoke.Get(file, key) //resultfmt.Println(string(res)) }Lazy example
funcTestGob(t*testing.T){file:="test/gob.db"DeleteFile(file) deferCloseAll() typePoststruct{IdintContentstringCategorystring } fori:=0; i<20; i++{post:=&Post{Id: i, Content: "Content:"+strconv.Itoa(i)} err:=SetGob(file, post.Id, post) ch(err, t) } fori:=0; i<20; i++{varpost=new(Post) err:=GetGob(file, i, post) ch(err, t) fmt.Println("i:", i, "Post:", post) } }Advanced example
typePoststruct{IdintContentstringCategorystring } funcmain(){posts:="test/posts"tags:="test/tags"varpairs [][]bytefori:=0; i<40; i++{id:=make([]byte, 4) binary.BigEndian.PutUint32(id, uint32(i)) post:=&Post{Id: i, Content: "Content:"+strconv.Itoa(i), Category: "Category:"+strconv.Itoa(i/10)} b, _:=json.Marshal(post) pairs=append(pairs, id) pairs=append(pairs, b) tag:=fmt.Sprintf("%s:%08d", strconv.Itoa(i/10), i) //store only tags keysslowpoke.Set(tags, []byte(tag), nil) } //store posts fastslowpoke.Sets(posts, pairs) //get last 2 post key with offset 2limit:=uint32(2) offset:=uint32(2) order:=false//desckeys, _:=slowpoke.Keys(posts, nil, limit, offset, order) fmt.Println(keys) //[[0 0 0 37] [0 0 0 36]]//get key/ valuesres:=slowpoke.Gets(posts, keys) fork, v:=rangeres{ifk%2==0{fmt.Print(binary.BigEndian.Uint32(v)) } else{varpPostjson.Unmarshal(v, &p) fmt.Println(p) } } //37{37 Content:37 Category:3}//36{36 Content:36 Category:3}//free from memoryslowpoke.Close(posts) slowpoke.Close(tags) //open Db and read tags by prefix 2:* in ascending ordertagsKeys, _:=slowpoke.Keys(tags, []byte("2:*"), 0, 0, true) for_, v:=rangetagsKeys{fmt.Print(string(v) +", ") } //2:00000020, 2:00000021, 2:00000022, 2:00000023, 2:00000024, 2:00000025, 2:00000026, 2:00000027, 2:00000028, 2:00000029, }Api
All methods are thread-safe.
- Set/Sets/SetGob
Store val and key. If the file does not exist it will be created.
- Get/Gets/GetGob
Return the value for the given key or nil and an error. Get will open the database if necessary.
- Keys
Return keys in ascending/descending order.
With limit and offset.
If from is not nil, return keys lexicographically greater than the from value.
If from ends with asterix *, return keys with the prefix equal to from without the asterix.
Status
Used in production (master branch)
Benchmark
Some tests, MacBook Pro (Retina, 13-inch, Early 2015)
Number of keys: 1000000 Minimum key size: 16, maximum key size: 64 Minimum value size: 128, maximum value size: 512 Concurrency: 2
| pogreb | goleveldb | bolt | badgerdb | pudge | slowpoke | pudge(mem) | |
|---|---|---|---|---|---|---|---|
| 1M (Put+Get), seconds | 187 | 38 | 126 | 34 | 23 | 23 | 2 |
| 1M Put, ops/sec | 5336 | 34743 | 8054 | 33539 | 47298 | 46789 | 439581 |
| 1M Get, ops/sec | 1782423 | 98406 | 499871 | 220597 | 499172 | 445783 | 1652069 |
| FileSize,Mb | 568 | 357 | 552 | 487 | 358 | 358 | 358 |