Added SQLite3 backend support.

backend.go

@@ -5,6 +5,6 @@ type Backend interface {
 	InTransaction() bool
 	Store(hash, key, value []byte) (bool, error)
 	BeginTransaction() error
-	CommitTransAction() error
+	CommitTransaction() error
 	Shutdown() error
 }

connection.go

@@ -85,7 +85,7 @@ func (c *Connection) Exec() bool {
 	}
 	arr := c.boolArray
 	c.boolArray = []bool{}
-	if err := c.backend.CommitTransAction(); err != nil {
+	if err := c.backend.CommitTransaction(); err != nil {
 		return c.writeError(err)
 	}
 	return c.writeBoolArray(arr)

leveldb.go

@@ -27,6 +27,11 @@ func NewLeveDBBackend(path string, cacheSize int) (ldb *LevelDBBackend, err erro
 }
 
 func (ldb *LevelDBBackend) Shutdown() error {
+    tx := ldb.tx
+    if tx != nil {
+        ldb.tx = nil
+        tx.Close()
+    }
 	ldb.db.Close()
 	ldb.cache.Close()
 	return nil
@@ -78,7 +83,7 @@ func (ldb *LevelDBBackend) BeginTransaction() error {
 	return nil
 }
 
-func (ldb *LevelDBBackend) CommitTransAction() error {
+func (ldb *LevelDBBackend) CommitTransaction() error {
 	tx := ldb.tx
 	ldb.tx = nil
 	wo := leveldb.NewWriteOptions()

main.go

@@ -13,9 +13,11 @@ func main() {
 
 	var port int
 	var host string
+	var driver string
 	var cacheSize int
 
 	flag.IntVar(&port, "port", 6379, "port to bind")
+	flag.StringVar(&driver, "driver", "leveldb", "type of database (leveldb, sqlite)")
 	flag.StringVar(&host, "host", "", "host to bind")
 	flag.IntVar(&cacheSize, "cache", 32, "cache size in MB")
 	flag.Parse()
@@ -29,9 +31,15 @@ func main() {
 	var err error
 	var backend Backend
 
+    if driver == "sqlite" {
+        if backend, err = NewSqliteBackend(args[0]); err != nil {
+            log.Fatal(err)
+        }
+    } else {
         if backend, err = NewLeveDBBackend(args[0], cacheSize); err != nil {
             log.Fatal(err)
         }
+    }
 	defer backend.Shutdown()
 
 	var listener net.Listener

parser.go

@@ -38,9 +38,7 @@ func (rp *RedisParser) nextLine() []byte {
 		rp.consumer.ConsumeError(err)
 		return nil
 	}
-	line = bytes.TrimRight(line, "\r\n")
-	log.Printf("%q", line)
-	return line
+	return bytes.TrimRight(line, "\r\n")
 }
 
 func (rp *RedisParser) dispatch(line []byte) bool {
@@ -179,13 +177,13 @@ func (rce *RedisCommandExecutor) execute() bool {
 		}
 		hash, ok1 := rce.args[1].([]byte)
 		key, ok2 := rce.args[2].([]byte)
-		block, ok3 := rce.args[3].([]byte)
+		value, ok3 := rce.args[3].([]byte)
 
 		if !ok1 || !ok2 || !ok3 {
 			log.Printf("WARM HSET data are not byte slices,")
 			return false
 		}
-		return rce.commands.Hset(hash, key, block)
+		return rce.commands.Hset(hash, key, value)
 
 	case "MULTI":
 		return rce.commands.Multi()
@@ -198,25 +196,14 @@ func (rce *RedisCommandExecutor) execute() bool {
 }
 
 func (rce *RedisCommandExecutor) ConsumeSimpleString(s string) bool {
-	log.Printf("simple string: %s", s)
 	return rce.push(s)
 }
 
-func shorten(data []byte) string {
-	if len(data) > 10 {
-		return fmt.Sprintf("%.10q...", data)
-	}
-	return fmt.Sprintf("%q", data)
-}
-
 func (rce *RedisCommandExecutor) ConsumeBulkString(data []byte) bool {
-	s := shorten(data)
-	log.Printf("buld string: len = %d: %s", len(data), s)
 	return rce.push(data)
 }
 
 func (rce *RedisCommandExecutor) ConsumeInteger(i int64) bool {
-	log.Printf("integer: %d", i)
 	return rce.push(i)
 }
 
@@ -226,7 +213,6 @@ func (rce *RedisCommandExecutor) ConsumeError(err error) bool {
 }
 
 func (rce *RedisCommandExecutor) ConsumeArray(i int64) bool {
-	log.Printf("array: %d", i)
 	if rce.missing > 0 {
 		log.Println("WARN: Nested arrays are not supported!")
 		return false

sqlite.go

@@ -0,0 +1,194 @@
+package main
+
+import (
+	"database/sql"
+	"log"
+	"strconv"
+	"sync"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+var globalLock sync.RWMutex
+
+const (
+	fetchSql  = "SELECT data FROM blocks WHERE pos = ?"
+	existsSql = "SELECT 1 FROM blocks WHERE pos = ?"
+	updateSql = "UPDATE blocks SET data = ? WHERE pos = ?"
+	insertSql = "INSERT INTO blocks (pos, data) VALUES (?, ?)"
+)
+
+type SqliteBackend struct {
+	db         *sql.DB
+	tx         *sql.Tx
+	existsStmt *sql.Stmt
+	fetchStmt  *sql.Stmt
+	insertStmt *sql.Stmt
+	updateStmt *sql.Stmt
+}
+
+func NewSqliteBackend(path string) (sqlb *SqliteBackend, err error) {
+
+	res := SqliteBackend{}
+
+	if res.db, err = sql.Open("sqlite3", path); err != nil {
+		return
+	}
+
+	if res.existsStmt, err = res.db.Prepare(existsSql); err != nil {
+		res.closeAll()
+		return
+	}
+
+	if res.fetchStmt, err = res.db.Prepare(fetchSql); err != nil {
+		res.closeAll()
+		return
+	}
+
+	if res.insertStmt, err = res.db.Prepare(insertSql); err != nil {
+		res.closeAll()
+		return
+	}
+
+	if res.updateStmt, err = res.db.Prepare(updateSql); err != nil {
+		res.closeAll()
+		return
+	}
+
+	sqlb = &res
+	return
+}
+
+func rollbackTx(tx **sql.Tx) error {
+	t := *tx
+	if t != nil {
+		*tx = nil
+		return t.Rollback()
+	}
+	return nil
+}
+
+func closeStmt(stmt **sql.Stmt) error {
+	s := *stmt
+	if s != nil {
+		*stmt = nil
+		return s.Close()
+	}
+	return nil
+}
+
+func closeDB(db **sql.DB) error {
+	d := *db
+	if d != nil {
+		*db = nil
+		return d.Close()
+	}
+	return nil
+}
+
+func (sqlb *SqliteBackend) closeAll() error {
+	rollbackTx(&sqlb.tx)
+	closeStmt(&sqlb.fetchStmt)
+	closeStmt(&sqlb.insertStmt)
+	closeStmt(&sqlb.updateStmt)
+	closeStmt(&sqlb.existsStmt)
+	return closeDB(&sqlb.db)
+}
+
+func (sqlb *SqliteBackend) Shutdown() error {
+	globalLock.Lock()
+	defer globalLock.Unlock()
+
+	return sqlb.closeAll()
+}
+
+func (sqlb *SqliteBackend) txStmt(stmt *sql.Stmt) *sql.Stmt {
+	if sqlb.tx != nil {
+		return sqlb.tx.Stmt(stmt)
+	}
+	return stmt
+}
+
+func bytes2pos(key []byte) (pos int64, err error) {
+	return strconv.ParseInt(string(key), 10, 64)
+}
+
+func (sqlb *SqliteBackend) Fetch(hash, key []byte) (data []byte, err error) {
+	var pos int64
+	if pos, err = bytes2pos(key); err != nil {
+		return
+	}
+
+	globalLock.RLock()
+	defer globalLock.RUnlock()
+
+	fetchStmt := sqlb.txStmt(sqlb.fetchStmt)
+	err2 := fetchStmt.QueryRow(pos).Scan(&data)
+	if err2 == sql.ErrNoRows {
+		return
+	}
+	err = err2
+	return
+}
+
+func (sqlb *SqliteBackend) InTransaction() bool {
+	return sqlb.tx != nil
+}
+
+func (sqlb *SqliteBackend) Store(hash, key, value []byte) (exists bool, err error) {
+	var pos int64
+	if pos, err = bytes2pos(key); err != nil {
+		return
+	}
+
+	globalLock.Lock()
+	defer globalLock.Unlock()
+
+	existsStmt := sqlb.txStmt(sqlb.existsStmt)
+	var x int
+	err2 := existsStmt.QueryRow(pos).Scan(&x)
+
+	if err2 == sql.ErrNoRows {
+		exists = false
+	} else if err2 != nil {
+		err = err2
+		return
+	} else {
+		exists = true
+	}
+
+	if exists {
+		updateStmt := sqlb.txStmt(sqlb.updateStmt)
+		_, err = updateStmt.Exec(value, pos)
+	} else {
+		insertStmt := sqlb.txStmt(sqlb.insertStmt)
+		_, err = insertStmt.Exec(pos, value)
+	}
+	return
+}
+
+func (sqlb *SqliteBackend) BeginTransaction() (err error) {
+	if sqlb.tx != nil {
+		log.Println("WARN: Already running transaction.")
+		return nil
+	}
+
+	globalLock.Lock()
+	defer globalLock.Unlock()
+	sqlb.tx, err = sqlb.db.Begin()
+	return
+}
+
+func (sqlb *SqliteBackend) CommitTransaction() error {
+
+	tx := sqlb.tx
+	if tx == nil {
+		log.Println("WARN: No transaction running.")
+		return nil
+	}
+
+	globalLock.Lock()
+	defer globalLock.Unlock()
+	sqlb.tx = nil
+	return tx.Commit()
+}