使用 Golang 编写 Redis 模块.zip

# Go Redis module go-rm will let you write redis module in golang. Read in | [中文](./README-zh_CN.md) | [English](./README.md) | [Spanish](./README-es.md) ## Modules * [redismodule](https://github.com/redismodule) * [rxhash](https://github.com/redismodule/rxhash) ## Demo ```bash # Ensure you installed the newest redis # for example by using brew you can # brew reinstall redis --HEAD # Build redis module go build -v -buildmode=c-shared github.com/redismodule/rxhash/cmd/rxhash # Start redis-server and load our module with debug log redis-server --loadmodule rxhash --loglevel debug ``` __Connect to out redis-server__ ```bash # Test hgetset redis-cli hset a a 1 #> (integer) 1 redis-cli hgetset a a 2 #> "1" redis-cli hget a a #> "2" # Return nil if field not exists redis-cli hgetset a b 2 #> (nil) redis-cli hgetset a b 3 #> "2" ``` Wow, it works, now you can distribute this redis module to you friends. :P ## How to write a module Implement a redis module is as easy as you write a cli app in go, this is all you need to implement above command. ```go package main import "github.com/wenerme/go-rm/rm" func main() { // In case someone try to run this rm.Run() } func init() { rm.Mod = CreateMyMod() } func CreateMyMod() *rm.Module { mod := rm.NewMod() mod.Name = "hashex" mod.Version = 1 mod.Commands = []rm.Command{CreateCommand_HGETSET()} return mod } func CreateCommand_HGETSET() rm.Command { return rm.Command{ Usage: "HGETSET key field value", Desc: `Sets the 'field' in Hash 'key' to 'value' and returns the previous value, if any. Reply: String, the previous value or NULL if 'field' didn't exist. `, Name: "hgetset", Flags: "write fast deny-oom", FirstKey:1, LastKey:1, KeyStep:1, Action: func(cmd rm.CmdContext) int { ctx, args := cmd.Ctx, cmd.Args if len(cmd.Args) != 4 { return ctx.WrongArity() } ctx.AutoMemory() key, ok := openHashKey(ctx, args[1]) if !ok { return rm.ERR } // get the current value of the hash element var val rm.String; key.HashGet(rm.HASH_NONE, cmd.Args[2], (*uintptr)(&val)) // set the element to the new value key.HashSet(rm.HASH_NONE, cmd.Args[2], cmd.Args[3]) if val.IsNull() { ctx.ReplyWithNull() } else { ctx.ReplyWithString(val) } return rm.OK }, } } // open the key and make sure it is indeed a Hash and not empty func openHashKey(ctx rm.Ctx, k rm.String) (rm.Key, bool) { key := ctx.OpenKey(k, rm.READ | rm.WRITE) if key.KeyType() != rm.KEYTYPE_EMPTY && key.KeyType() != rm.KEYTYPE_HASH { ctx.ReplyWithError(rm.ERRORMSG_WRONGTYPE) return rm.Key(0), false } return key, true } ``` ## Fantasy * A module management module, supplies * mod.search * Search module from repository(github?) * Repository structure like this ``` /namespace /module-name /bin /darwin_amd64 module-name.so module-name.sha /linux_amd64 module-name.go ``` * mod.get * Download module to ~/.redismodule * Because module is write in go, so we can build for almost any platform * We can use tag/commit to version the binary, so we can download the old version too * mod.install * Install downloaded module by calling redis command * ... * A cluster management module * Easy to create/manage/monitor redis3 cluster * A json data type to demonstration how to add new data type in redis. * json.fmt key template * json.path key path \[pretty] * json.get key \[pretty] * json.set key value * this will validate the json format ## Pitfall * C can not call Go function, so every callback is pre-generated * 200 commands at most * 5 data type at most * limits are easy to change, just need a proper max value * Go can not call var_args, function call is pre-generated * HashSet/HashGet can accept 20 args at most * limits are easy to change, just need a proper max value * Don't know what happens when unload a golang shared module * Single module * Multi module * Is there runtime are shared ? * Module write in go can not report it's memory usage to redis, max memory limits is useless * If a module write in go also include a third party write in other language, the memory usage is unknown * Module can only accept command, seems there is no way to call redis initiative. ## TODO * Find a proper limits for data types and var_args