added Null engine and refactored some code

Author: alash3al

README.md

@@ -19,7 +19,7 @@ Features
 =========
 - Core data structure: `KV`, `List`, `Hashmap` with advanced implementations.
 - Advanced Publish/Subscribe using webhook and websocket!
-- Pluggable Storage Engine (`badgerdb`, `boltdb`, 'leveldb')
+- Pluggable Storage Engine (`badgerdb`, `boltdb`, `leveldb`)
 - Very compatible with any `redis client` including `redis-cli`
 - Standalone with no external dependencies
 - Helpers commands for `Time`, `Encode <hex|md5|sha1|sha256|sha512> <payload>`, `RANDINT`, `RANDSTR`

commands_strings.go

@@ -30,10 +30,16 @@ func setCommand(c Context) {
 		ttlVal = 0
 	}
 
+	// if *flagACK {
 	if err := c.db.Set(k, v, ttlVal); err != nil {
 		c.WriteError(err.Error())
 		return
 	}
+	// } else {
+	// 	kvjobs <- func() {
+	// 		c.db.Set(k, v, ttlVal)
+	// 	}
+	// }
 
 	c.WriteString("OK")
 }

helpers_db.go

@@ -5,13 +5,11 @@ package main
 
 import (
 	"errors"
-	"io/ioutil"
-	"log"
-	"os"
 	"path/filepath"
 	"strings"
 
-	"github.com/alash3al/color"
+	"github.com/alash3al/redix/kvstore/null"
+
 	"github.com/alash3al/redix/kvstore"
 	"github.com/alash3al/redix/kvstore/badgerdb"
 	"github.com/alash3al/redix/kvstore/boltdb"
@@ -46,27 +44,8 @@ func openDB(engine, dbpath string) (kvstore.DB, error) {
 		return boltdb.OpenBolt(dbpath)
 	case "leveldb":
 		return leveldb.OpenLevelDB(dbpath)
-	}
-}
-
-// initDBs - initialize databases from the disk for faster access
-func initDBs() {
-	os.MkdirAll(*flagStorageDir, 0644)
-
-	dirs, _ := ioutil.ReadDir(*flagStorageDir)
-
-	for _, f := range dirs {
-		if !f.IsDir() {
-			continue
-		}
-
-		name := filepath.Base(f.Name())
-
-		_, err := selectDB(name)
-		if err != nil {
-			log.Println(color.RedString(err.Error()))
-			continue
-		}
+	case "null":
+		return null.OpenNull()
 	}
 }
 

init.go

@@ -7,6 +7,7 @@ import (
 	"flag"
 	"fmt"
 	"io/ioutil"
+	"log"
 	"net/url"
 	"os"
 	"path/filepath"
@@ -50,8 +51,6 @@ func init() {
 		return &ret
 	})()
 
-	initDBs()
-
 	snowflakenode, err := snowflake.NewNode(1)
 	if err != nil {
 		fmt.Println(color.RedString(err.Error()))
@@ -60,4 +59,27 @@ func init() {
 	}
 
 	snowflakeGenerator = snowflakenode
+
+	initDBs()
+}
+
+// initDBs - initialize databases from the disk for faster access
+func initDBs() {
+	os.MkdirAll(*flagStorageDir, 0644)
+
+	dirs, _ := ioutil.ReadDir(*flagStorageDir)
+
+	for _, f := range dirs {
+		if !f.IsDir() {
+			continue
+		}
+
+		name := filepath.Base(f.Name())
+
+		_, err := selectDB(name)
+		if err != nil {
+			log.Println(color.RedString(err.Error()))
+			continue
+		}
+	}
 }

kvstore/null/null.go

@@ -0,0 +1,68 @@
+// Copyright 2018 The Redix Authors. All rights reserved.
+// Use of this source code is governed by a Apache 2.0
+// license that can be found in the LICENSE file.
+//
+// null is a db engine based on `/dev/null` style
+package null
+
+import (
+	"github.com/alash3al/redix/kvstore"
+)
+
+// Null - represents a Null db implementation
+type Null struct{}
+
+// OpenNull - Opens the specified path
+func OpenNull() (*Null, error) {
+	return new(Null), nil
+}
+
+// Size - returns the size of the database in bytes
+func (ldb *Null) Size() int64 {
+	return 0
+}
+
+// GC - runs the garbage collector
+func (ldb *Null) GC() error {
+	return nil
+}
+
+// Incr - increment the key by the specified value
+func (ldb *Null) Incr(k string, by int64) (int64, error) {
+	return 1, nil
+}
+
+// Set - sets a key with the specified value and optional ttl
+func (ldb *Null) Set(k, v string, ttl int) error {
+	return nil
+}
+
+// MSet - sets multiple key-value pairs
+func (ldb *Null) MSet(data map[string]string) error {
+	return nil
+}
+
+// Get - fetches the value of the specified k
+func (ldb *Null) Get(k string) (string, error) {
+	return "", nil
+}
+
+// MGet - fetch multiple values of the specified keys
+func (ldb *Null) MGet(keys []string) []string {
+	return nil
+}
+
+// TTL - returns the time to live of the specified key's value
+func (ldb *Null) TTL(key string) int64 {
+	return -2
+}
+
+// Del - removes key(s) from the store
+func (ldb *Null) Del(keys []string) error {
+	return nil
+}
+
+// Scan - iterate over the whole store using the handler function
+func (ldb *Null) Scan(scannerOpt kvstore.ScannerOptions) error {
+	return nil
+}

main.go

@@ -5,12 +5,16 @@ package main
 
 import (
 	"fmt"
+	"strconv"
 
 	"github.com/alash3al/go-color"
 )
 
 func main() {
+	fmt.Println(color.MagentaString(redixBrand))
 	fmt.Printf("⇨ redix server version: %s \n", color.GreenString(redixVersion))
+	fmt.Printf("⇨ redix selected engine: %s \n", color.GreenString(*flagEngine))
+	fmt.Printf("⇨ redix workers count: %s \n", color.GreenString(strconv.Itoa(*flagWorkers)))
 	fmt.Printf("⇨ redix resp server available at: %s \n", color.GreenString(*flagRESPListenAddr))
 	fmt.Printf("⇨ redix http server available at: %s \n", color.GreenString(*flagHTTPListenAddr))
 

vars.go

@@ -21,6 +21,7 @@ var (
 	flagEngineOpions   = flag.String("engine-options", "", "options related to used engine in the url query format, i.e (opt1=val2&opt2=val2)")
 	flagWorkers        = flag.Int("workers", runtime.NumCPU(), "the default workers number")
 	flagVerbose        = flag.Bool("verbose", false, "verbose or not")
+	flagACK            = flag.Bool("ack", true, "acknowledge write or return immediately")
 )
 
 var (
@@ -29,6 +30,7 @@ var (
 	webhooks           *sync.Map
 	websockets         *sync.Map
 	snowflakeGenerator *snowflake.Node
+	kvjobs             chan func()
 )
 
 var (
@@ -114,7 +116,7 @@ var (
 		"badgerdb": true,
 		"boltdb":   true,
 		"leveldb":  true,
-		"tikv":     true,
+		"null":     true,
 	}
 	engineOptions         = url.Values{}
 	defaultPubSubAllTopic = "*"
@@ -124,7 +126,7 @@ const (
 	redixVersion = "1.9"
 	redixBrand   = `
 
-		_______  _______  ______  _________         
+		 _______  _______  ______  _________         
 		(  ____ )(  ____ \(  __  \ \__   __/|\     /|
 		| (    )|| (    \/| (  \  )   ) (   ( \   / )
 		| (____)|| (__    | |   ) |   | |    \ (_) /