opt: performance of lookupCommand

Makefile

@@ -9,7 +9,7 @@ test-cover:
 	go tool cover -html=coverage.txt -o coverage.html
 
 pprof:
-	go tool pprof -http=:18081 "http://localhost:6060/debug/pprof/profile?seconds=30"
+	go tool pprof -http=:18081 "http://192.168.1.6:6060/debug/pprof/profile?seconds=30"
 
 heap:
 	go tool pprof http://localhost:6060/debug/pprof/heap

epoll.go

@@ -60,8 +60,9 @@ func (e *epoll) Remove(conn net.Conn) error {
 
 func (e *epoll) Wait() ([]net.Conn, error) {
 	events := make([]unix.EpollEvent, 100)
+
 retry:
-	n, err := unix.EpollWait(e.fd, events, 0)
+	n, err := unix.EpollWait(e.fd, events, 100)
 	if err != nil {
 		if err == unix.EINTR {
 			goto retry

go.mod

@@ -7,7 +7,6 @@ require (
 	github.com/deckarep/golang-set/v2 v2.6.0
 	github.com/redis/go-redis/v9 v9.5.2
 	github.com/sakeven/RbTree v0.0.0-20240321014605-9899538dc980
-	github.com/sourcegraph/conc v0.3.0
 	github.com/stretchr/testify v1.9.0
 	github.com/xgzlucario/GigaCache v0.0.0-20240531152919-576765cef731
 	github.com/xgzlucario/quicklist v0.0.0-20240530174658-6f1a884f579b
@@ -22,8 +21,6 @@ require (
 	github.com/kr/text v0.2.0 // indirect
 	github.com/mschoch/smat v0.2.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	go.uber.org/atomic v1.7.0 // indirect
-	go.uber.org/multierr v1.9.0 // indirect
 	golang.org/x/exp v0.0.0-20240531132922-fd00a4e0eefc // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -31,21 +31,14 @@ github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZV
 github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
 github.com/sakeven/RbTree v0.0.0-20240321014605-9899538dc980 h1:t5uAkycj8WepkboiZvJzHB+FvkNj+P6Z2dEN4pFajU4=
 github.com/sakeven/RbTree v0.0.0-20240321014605-9899538dc980/go.mod h1:zwEumjdcK6Q/ky/gFPqMviw1p7ZUb+B3pU4ybgOHvns=
-github.com/sourcegraph/conc v0.3.0 h1:OQTbbt6P72L20UqAkXXuLOj79LfEanQ+YQFNpLA9ySo=
-github.com/sourcegraph/conc v0.3.0/go.mod h1:Sdozi7LEKbFPqYX2/J+iBAM6HpqSLTASQIKqDmF7Mt0=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
 github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 github.com/xgzlucario/GigaCache v0.0.0-20240531152919-576765cef731 h1:frRQxMZFCPWfoiWau4bPcYmNDGNVPLqM9nqnsp6Uakg=
 github.com/xgzlucario/GigaCache v0.0.0-20240531152919-576765cef731/go.mod h1:sPwGPAuvd9WdiONTmusXGNocqcY5L/J7+st1upAMlX8=
 github.com/xgzlucario/quicklist v0.0.0-20240530174658-6f1a884f579b h1:C/+nN/kFJ6yrmEhIu+5Ra2jx/W8w+Ayu8pTiZfuU5Xc=
 github.com/xgzlucario/quicklist v0.0.0-20240530174658-6f1a884f579b/go.mod h1:1ZgyZNk91XIllYdOPpwP+9L2RCw6QGSy6alTYF+Z0iU=
-go.uber.org/atomic v1.7.0 h1:ADUqmZGgLDDfbSL9ZmPxKTybcoEYHgpYfELNoN+7hsw=
-go.uber.org/atomic v1.7.0/go.mod h1:fEN4uk6kAWBTFdckzkM89CLk9XfWZrxpCo0nPH17wJc=
-go.uber.org/multierr v1.9.0 h1:7fIwc/ZtS0q++VgcfqFDxSBZVv/Xo49/SYnDFupUwlI=
-go.uber.org/multierr v1.9.0/go.mod h1:X2jQV1h+kxSjClGpnseKVIxpmcjrj7MNnI0bnlfKTVQ=
 golang.org/x/exp v0.0.0-20240531132922-fd00a4e0eefc h1:O9NuF4s+E/PvMIy+9IUZB9znFwUIXEWSstNjek6VpVg=
 golang.org/x/exp v0.0.0-20240531132922-fd00a4e0eefc/go.mod h1:XtvwrStGgqGPLc4cjQfWqZHG1YFdYs6swckp8vpsjnc=
 golang.org/x/sys v0.20.0 h1:Od9JTbYCk261bKm4M/mw7AklTlFYIa0bIp9BgSm1S8Y=

resp_test.go

@@ -3,7 +3,10 @@ package main
 import (
 	"bytes"
 	"errors"
+	"strconv"
+	"strings"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/assert"
 )
@@ -99,6 +102,15 @@ func TestValue(t *testing.T) {
 		data := value.Marshal()
 		assert.Equal(string(data), ErrUnknownType.Error())
 	})
+
+	t.Run("to-lower-nocopy", func(t *testing.T) {
+		for i := 0; i < 1000; i++ {
+			timeFormat := strconv.FormatInt(time.Now().UnixNano(), 36)
+			lower := strings.ToLower(timeFormat)
+			lower2 := ToLowerNoCopy([]byte(lower))
+			assert.Equal(lower, string(lower2))
+		}
+	})
 }
 
 func BenchmarkRESP(b *testing.B) {

rotom.go

@@ -7,10 +7,7 @@ import (
 	"log"
 	"net"
 	"os"
-	"runtime"
-	"strings"
 
-	"github.com/sourcegraph/conc/pool"
 	cache "github.com/xgzlucario/GigaCache"
 	"github.com/xgzlucario/rotom/structx"
 )
@@ -30,21 +27,34 @@ type DB struct {
 }
 
 type Server struct {
-	config     *Config
-	epoller    *epoll
-	workerPool *pool.Pool
+	config  *Config
+	epoller *epoll
 }
 
 type Command struct {
-	name    string
+	// name is command string name.
+	// it should consist of all lowercase letters.
+	name string
+
+	// handler is this command real database handler function.
 	handler func([]Value) Value
-	arity   int // arity represents the minimal number of arguments that command accepts.
-	aofNeed bool
+
+	// arity represents the minimal number of arguments that command accepts.
+	arity int
+
+	// persist indicates whether this command needs to be persisted.
+	// effective when `appendonly` is true.
+	persist bool
 }
 
 var (
-	db       DB
-	server   Server
+	// db is the main database object.
+	db DB
+
+	// server is the main server object.
+	server Server
+
+	// cmdTable is the list of all available commands.
 	cmdTable []Command = []Command{
 		{"ping", pingCommand, 0, false},
 		{"set", setCommand, 2, true},
@@ -53,22 +63,20 @@ var (
 		{"hget", hgetCommand, 2, false},
 		{"hdel", hdelCommand, 2, true},
 		{"hgetall", hgetallCommand, 1, false},
-		// TODO
 	}
 )
 
-func lookupCommand(command string) (*Command, error) {
-	command = strings.ToLower(command)
+func lookupCommand(command []byte) (*Command, error) {
+	cmdStr := b2s(ToLowerNoCopy(command))
 	for _, c := range cmdTable {
-		if c.name == command {
+		if c.name == cmdStr {
 			return &c, nil
 		}
 	}
 	return nil, fmt.Errorf("invalid command: %s", command)
 }
 
 func (cmd *Command) processCommand(args []Value) Value {
-	// Check command arguments.
 	if len(args) < cmd.arity {
 		return newErrValue(ErrWrongArgs(cmd.name))
 	}
@@ -96,7 +104,7 @@ func InitDB(config *Config) (err error) {
 			command := value.array[0].bulk
 			args := value.array[1:]
 
-			cmd, err := lookupCommand(b2s(command))
+			cmd, err := lookupCommand(command)
 			if err == nil {
 				cmd.processCommand(args)
 			}
@@ -123,9 +131,6 @@ func (server *Server) RunServe() {
 	}
 	server.epoller = epoller
 
-	// Start goroutine workerPool.
-	server.workerPool = pool.New().WithMaxGoroutines(runtime.NumCPU())
-
 	go func() {
 		var buf = make([]byte, 512)
 
@@ -185,26 +190,20 @@ func (server *Server) handleConnection(buf []byte, conn net.Conn) {
 		command := value.array[0].bulk
 		var res Value
 
-		// Lookup for command.
-		cmd, err := lookupCommand(b2s(command))
+		cmd, err := lookupCommand(command)
 		if err != nil {
 			res = newErrValue(err)
 
 		} else {
-			// Process command.
 			res = cmd.processCommand(value.array[1:])
 
-			// Write aof file after proccess success.
-			if server.config.AppendOnly && cmd.aofNeed && res.typ != ERROR {
+			if server.config.AppendOnly && cmd.persist && res.typ != ERROR {
 				db.aof.Write(buf)
 			}
 		}
 
-		// Async write result.
-		server.workerPool.Go(func() {
-			if _, err = conn.Write(res.Marshal()); err != nil {
-				log.Println("write reply error:", err)
-			}
-		})
+		if _, err = conn.Write(res.Marshal()); err != nil {
+			log.Println("write reply error:", err)
+		}
 	}
 }

utils.go

@@ -5,3 +5,12 @@ import "unsafe"
 func b2s(b []byte) string {
 	return *(*string)(unsafe.Pointer(&b))
 }
+
+func ToLowerNoCopy(b []byte) []byte {
+	for i, c := range b {
+		if c >= 'A' && c <= 'Z' {
+			b[i] += 'a' - 'A'
+		}
+	}
+	return b
+}