Add server starter

Open and open funtions renamed in db.go as open and opendAndLoad function names. Open name is used
in server.go to create a connection for server and database. Due to renaming Open and open functions
, test files, example code in /example and README changed.

README.md

@@ -20,7 +20,7 @@ import (
 )
 
 func main() {
-    db, err := kvs.Open("users")
+    db, err := kvs.Open(":1234", "users")
     if err != nil {
         log.Fatalf(err.Error())
     }

db.go

@@ -30,10 +30,10 @@ const (
 	fileExtension = ".kvs"
 )
 
-// Open creates data file for newly creating database. If the database file is
+// open creates data file for newly creating database. If the database file is
 // already exists, it returns error without creating anything. name indicates
 // database name.
-func Open(name string) (*Kvs, error) {
+func open(name string) (*Kvs, error) {
 	fullPath := baseDir + name + fileExtension
 
 	// Check database's base directory
@@ -58,12 +58,13 @@ func Open(name string) (*Kvs, error) {
 			kv:     m,
 		}, nil
 	} else {
-		return open(name)
+		return openAndLoad(name)
 	}
 }
 
-// open opens the named database for file operations.
-func open(dbName string) (*Kvs, error) {
+// openAndLoad opens the named database file for file operations. Also, loads
+// the database file into map to in-memory operations.
+func openAndLoad(dbName string) (*Kvs, error) {
 	mu := sync.Mutex{}
 	mu.Lock()
 	defer mu.Unlock()

db_test.go

@@ -6,7 +6,7 @@ import (
 )
 
 func TestOpen(t *testing.T) {
-	tmpDb, err := Open(t.Name())
+	tmpDb, err := open(t.Name())
 	if err != nil {
 		t.Fatalf(err.Error())
 	}
@@ -25,7 +25,7 @@ func TestOpen(t *testing.T) {
 }
 
 func TestOpenExistsFile(t *testing.T) {
-	tmpDb, err := Open(t.Name())
+	tmpDb, err := open(t.Name())
 	if err != nil {
 		t.Fatalf(err.Error())
 	}
@@ -38,7 +38,7 @@ func TestOpenExistsFile(t *testing.T) {
 	}
 	t.Logf("TmpDb created: %s", t.Name())
 
-	tmpDb2, err := Open(t.Name())
+	tmpDb2, err := open(t.Name())
 	if err != nil {
 		t.Fatalf("It should not be nil.")
 	}
@@ -55,7 +55,7 @@ func TestOpenExistsFile(t *testing.T) {
 }
 
 func TestKvs_Close(t *testing.T) {
-	db, err := Open(t.Name())
+	db, err := open(t.Name())
 	if err != nil {
 		t.Fatalf(err.Error())
 	}
@@ -75,7 +75,7 @@ func TestKvs_Close(t *testing.T) {
 }
 
 func TestWrite(t *testing.T) {
-	db, err := Open(t.Name())
+	db, err := open(t.Name())
 	if err != nil {
 		t.Fatalf(err.Error())
 	}
@@ -104,7 +104,7 @@ func TestWrite(t *testing.T) {
 }
 
 func TestLoad(t *testing.T) {
-	db, err := Open(t.Name())
+	db, err := open(t.Name())
 	if err != nil {
 		t.Fatalf(err.Error())
 	}

example/main.go

@@ -7,7 +7,7 @@ import (
 )
 
 func main() {
-	db, err := kvs.Open("users")
+	db, err := kvs.Open(":1234", "users")
 	if err != nil {
 		log.Fatalf(err.Error())
 	}

get_test.go

@@ -6,7 +6,7 @@ import (
 )
 
 func TestKvs_GetEmpty(t *testing.T) {
-	db, err := Open(t.Name())
+	db, err := open(t.Name())
 	if err != nil {
 		t.Fatalf(err.Error())
 	}
@@ -32,7 +32,7 @@ func TestKvs_GetEmpty(t *testing.T) {
 }
 
 func TestKvs_Get(t *testing.T) {
-	db, err := Open(t.Name())
+	db, err := open(t.Name())
 	if err != nil {
 		t.Fatalf(err.Error())
 	}

server.go

@@ -0,0 +1,24 @@
+package kvs
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+)
+
+// Open creates an HTTP and database connection. HTTP connection listens HTTP
+// requests from client and database connection listens database commands from
+// server. addr is the HTTP address and dbName is the database name. If HTTP
+// address is empty, localhost and default port is used. In contrast, dbName
+// needs to be specified. If it is not specified, it returns error and the
+// connection is not established.
+func Open(addr string, dbName string) (*Kvs, error) {
+	if dbName == "" {
+		return nil, fmt.Errorf("empty database name is not valid")
+	}
+	if addr == "" {
+		addr = ":1234"
+	}
+	go log.Fatal(http.ListenAndServe(addr, nil))
+	return open(dbName)
+}

set_test.go

@@ -6,7 +6,7 @@ import (
 )
 
 func TestKvs_Set(t *testing.T) {
-	db, err := Open(t.Name())
+	db, err := open(t.Name())
 	if err != nil {
 		t.Fatalf(err.Error())
 	}