THRIFT-2132 Go: Support for Multiplexing Services on any Transport, Protocol and Server
Client: Go
Patch: Aleksey Pesternikov
diff --git a/lib/go/test/Makefile.am b/lib/go/test/Makefile.am
index 3055942..ca8fa64 100644
--- a/lib/go/test/Makefile.am
+++ b/lib/go/test/Makefile.am
@@ -24,11 +24,13 @@
 gopath: $(top_srcdir)/compiler/cpp/thrift $(THRIFTTEST) \
 				IncludesTest.thrift \
 				NamespacedTest.thrift \
+				MultiplexedProtocolTest.thrift \
 				OnewayTest.thrift
 	mkdir -p gopath/src
 	grep -v list.*map.*list.*map $(THRIFTTEST) > ThriftTest.thrift
 	$(THRIFT) -r IncludesTest.thrift
 	$(THRIFT) BinaryKeyTest.thrift
+	$(THRIFT) MultiplexedProtocolTest.thrift
 	$(THRIFT) OnewayTest.thrift
 	ln -nfs ../../../thrift gopath/src/thrift
 	ln -nfs ../../tests gopath/src/tests
diff --git a/lib/go/test/MultiplexedProtocolTest.thrift b/lib/go/test/MultiplexedProtocolTest.thrift
new file mode 100644
index 0000000..0e21061
--- /dev/null
+++ b/lib/go/test/MultiplexedProtocolTest.thrift
@@ -0,0 +1,27 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements. See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership. The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License. You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied. See the License for the
+# specific language governing permissions and limitations
+# under the License.
+#
+
+service First {
+	i64 returnOne();
+}
+
+service Second {
+	i64 returnTwo();
+}
+
diff --git a/lib/go/test/tests/multiplexed_protocol_test.go b/lib/go/test/tests/multiplexed_protocol_test.go
new file mode 100644
index 0000000..ee14ee8
--- /dev/null
+++ b/lib/go/test/tests/multiplexed_protocol_test.go
@@ -0,0 +1,163 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package tests
+
+import (
+	"MuliplexedProtocolTest"
+	"net"
+	"testing"
+	"thrift"
+	"time"
+)
+
+func FindAvailableTCPServerPort() net.Addr {
+	if l, err := net.Listen("tcp", "127.0.0.1:0"); err != nil {
+		panic("Could not find available server port")
+	} else {
+		defer l.Close()
+		return l.Addr()
+	}
+}
+
+type FirstImpl struct{}
+
+func (f *FirstImpl) ReturnOne() (r int64, err error) {
+	return 1, nil
+}
+
+type SecondImpl struct{}
+
+func (s *SecondImpl) ReturnTwo() (r int64, err error) {
+	return 2, nil
+}
+
+const TIMEOUT = time.Second
+
+var addr net.Addr
+var server *thrift.TSimpleServer
+
+var processor = thrift.NewTMultiplexedProcessor()
+
+func TestInitTwoServers(t *testing.T) {
+	var err error
+	protocolFactory := thrift.NewTBinaryProtocolFactoryDefault()
+	transportFactory := thrift.NewTTransportFactory()
+	transportFactory = thrift.NewTFramedTransportFactory(transportFactory)
+	addr = FindAvailableTCPServerPort()
+	serverTransport, err := thrift.NewTServerSocketTimeout(addr.String(), TIMEOUT)
+	if err != nil {
+		t.Fatal("Unable to create server socket", err)
+	}
+	server = thrift.NewTSimpleServer4(processor, serverTransport, transportFactory, protocolFactory)
+
+	firstProcessor := MuliplexedProtocolTest.NewFirstProcessor(&FirstImpl{})
+	processor.RegisterProcessor("FirstService", firstProcessor)
+
+	secondProcessor := MuliplexedProtocolTest.NewSecondProcessor(&SecondImpl{})
+	processor.RegisterProcessor("SecondService", secondProcessor)
+
+	go server.Serve()
+}
+
+var firstClient *MuliplexedProtocolTest.FirstClient
+
+func TestInitClient1(t *testing.T) {
+	socket := thrift.NewTSocketFromAddrTimeout(addr, TIMEOUT)
+	transport := thrift.NewTFramedTransport(socket)
+	var protocol thrift.TProtocol = thrift.NewTBinaryProtocolTransport(transport)
+	protocol = thrift.NewTMultiplexedProtocol(protocol, "FirstService")
+	firstClient = MuliplexedProtocolTest.NewFirstClientProtocol(transport, protocol, protocol)
+	err := transport.Open()
+	if err != nil {
+		t.Fatal("Unable to open client socket", err)
+	}
+}
+
+var secondClient *MuliplexedProtocolTest.SecondClient
+
+func TestInitClient2(t *testing.T) {
+	socket := thrift.NewTSocketFromAddrTimeout(addr, TIMEOUT)
+	transport := thrift.NewTFramedTransport(socket)
+	var protocol thrift.TProtocol = thrift.NewTBinaryProtocolTransport(transport)
+	protocol = thrift.NewTMultiplexedProtocol(protocol, "SecondService")
+	secondClient = MuliplexedProtocolTest.NewSecondClientProtocol(transport, protocol, protocol)
+	err := transport.Open()
+	if err != nil {
+		t.Fatal("Unable to open client socket", err)
+	}
+}
+
+//create client without service prefix
+func createLegacyClient(t *testing.T) *MuliplexedProtocolTest.SecondClient {
+	socket := thrift.NewTSocketFromAddrTimeout(addr, TIMEOUT)
+	transport := thrift.NewTFramedTransport(socket)
+	var protocol thrift.TProtocol = thrift.NewTBinaryProtocolTransport(transport)
+	legacyClient := MuliplexedProtocolTest.NewSecondClientProtocol(transport, protocol, protocol)
+	err := transport.Open()
+	if err != nil {
+		t.Fatal("Unable to open client socket", err)
+	}
+	return legacyClient
+}
+
+func TestCallFirst(t *testing.T) {
+	ret, err := firstClient.ReturnOne()
+	if err != nil {
+		t.Fatal("Unable to call first server:", err)
+	}
+	if ret != 1 {
+		t.Fatal("Unexpected result from server: ", ret)
+	}
+}
+
+func TestCallSecond(t *testing.T) {
+	ret, err := secondClient.ReturnTwo()
+	if err != nil {
+		t.Fatal("Unable to call second server:", err)
+	}
+	if ret != 2 {
+		t.Fatal("Unexpected result from server: ", ret)
+	}
+}
+
+func TestCallLegacy(t *testing.T) {
+	legacyClient := createLegacyClient(t)
+	ret, err := legacyClient.ReturnTwo()
+	//expect error since default processor is not registered
+	if err == nil {
+		t.Fatal("Expecting error")
+	}
+	//register default processor and call again
+	processor.RegisterDefault(MuliplexedProtocolTest.NewSecondProcessor(&SecondImpl{}))
+	legacyClient = createLegacyClient(t)
+	ret, err = legacyClient.ReturnTwo()
+	if err != nil {
+		t.Fatal("Unable to call legacy server:", err)
+	}
+	if ret != 2 {
+		t.Fatal("Unexpected result from server: ", ret)
+	}
+}
+
+func TestShutdownServerAndClients(t *testing.T) {
+	firstClient.Transport.Close()
+	secondClient.Transport.Close()
+	server.Stop()
+}
diff --git a/lib/go/thrift/multiplexed_protocol.go b/lib/go/thrift/multiplexed_protocol.go
new file mode 100644
index 0000000..3157e0d
--- /dev/null
+++ b/lib/go/thrift/multiplexed_protocol.go
@@ -0,0 +1,169 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package thrift
+
+import (
+	"fmt"
+	"strings"
+)
+
+/*
+TMultiplexedProtocol is a protocol-independent concrete decorator
+that allows a Thrift client to communicate with a multiplexing Thrift server,
+by prepending the service name to the function name during function calls.
+
+NOTE: THIS IS NOT USED BY SERVERS.  On the server, use TMultiplexedProcessor to handle request
+from a multiplexing client.
+
+This example uses a single socket transport to invoke two services:
+
+socket := thrift.NewTSocketFromAddrTimeout(addr, TIMEOUT)
+transport := thrift.NewTFramedTransport(socket)
+protocol := thrift.NewTBinaryProtocolTransport(transport)
+
+mp := thrift.NewTMultiplexedProtocol(protocol, "Calculator")
+service := Calculator.NewCalculatorClient(mp)
+
+mp2 := thrift.NewTMultiplexedProtocol(protocol, "WeatherReport")
+service2 := WeatherReport.NewWeatherReportClient(mp2)
+
+err := transport.Open()
+if err != nil {
+	t.Fatal("Unable to open client socket", err)
+}
+
+fmt.Println(service.Add(2,2))
+fmt.Println(service2.GetTemperature())
+*/
+
+type TMultiplexedProtocol struct {
+	TProtocol
+	serviceName string
+}
+
+const MULTIPLEXED_SEPARATOR = ":"
+
+func NewTMultiplexedProtocol(protocol TProtocol, serviceName string) *TMultiplexedProtocol {
+	return &TMultiplexedProtocol{
+		TProtocol:   protocol,
+		serviceName: serviceName,
+	}
+}
+
+func (t *TMultiplexedProtocol) WriteMessageBegin(name string, typeId TMessageType, seqid int32) error {
+	if typeId == CALL || typeId == ONEWAY {
+		return t.TProtocol.WriteMessageBegin(t.serviceName+MULTIPLEXED_SEPARATOR+name, typeId, seqid)
+	} else {
+		return t.TProtocol.WriteMessageBegin(name, typeId, seqid)
+	}
+}
+
+/*
+TMultiplexedProcessor is a TProcessor allowing
+a single TServer to provide multiple services.
+
+To do so, you instantiate the processor and then register additional
+processors with it, as shown in the following example:
+
+var processor = thrift.NewTMultiplexedProcessor()
+
+firstProcessor :=
+processor.RegisterProcessor("FirstService", firstProcessor)
+
+processor.registerProcessor(
+  "Calculator",
+  Calculator.NewCalculatorProcessor(&CalculatorHandler{}),
+)
+
+processor.registerProcessor(
+  "WeatherReport",
+  WeatherReport.NewWeatherReportProcessor(&WeatherReportHandler{}),
+)
+
+serverTransport, err := thrift.NewTServerSocketTimeout(addr, TIMEOUT)
+if err != nil {
+  t.Fatal("Unable to create server socket", err)
+}
+server := thrift.NewTSimpleServer2(processor, serverTransport)
+server.Serve();
+*/
+
+type TMultiplexedProcessor struct {
+	serviceProcessorMap map[string]TProcessor
+	DefaultProcessor    TProcessor
+}
+
+func NewTMultiplexedProcessor() *TMultiplexedProcessor {
+	return &TMultiplexedProcessor{
+		serviceProcessorMap: make(map[string]TProcessor),
+	}
+}
+
+func (t *TMultiplexedProcessor) RegisterDefault(processor TProcessor) {
+	t.DefaultProcessor = processor
+}
+
+func (t *TMultiplexedProcessor) RegisterProcessor(name string, processor TProcessor) {
+	if t.serviceProcessorMap == nil {
+		t.serviceProcessorMap = make(map[string]TProcessor)
+	}
+	t.serviceProcessorMap[name] = processor
+}
+
+func (t *TMultiplexedProcessor) Process(in, out TProtocol) (bool, TException) {
+	name, typeId, seqid, err := in.ReadMessageBegin()
+	if err != nil {
+		return false, err
+	}
+	if typeId != CALL && typeId != ONEWAY {
+		return false, fmt.Errorf("Unexpected message type %v", typeId)
+	}
+	//extract the service name
+	v := strings.SplitN(name, MULTIPLEXED_SEPARATOR, 2)
+	if len(v) != 2 {
+		if t.DefaultProcessor != nil {
+			smb := NewStoredMessageProtocol(in, name, typeId, seqid)
+			return t.DefaultProcessor.Process(smb, out)
+		}
+		return false, fmt.Errorf("Service name not found in message name: %s.  Did you forget to use a TMultiplexProtocol in your client?", name)
+	}
+	actualProcessor, ok := t.serviceProcessorMap[v[0]]
+	if !ok {
+		return false, fmt.Errorf("Service name not found: %s.  Did you forget to call registerProcessor()?", v[0])
+	}
+	smb := NewStoredMessageProtocol(in, v[1], typeId, seqid)
+	return actualProcessor.Process(smb, out)
+}
+
+//Protocol that use stored message for ReadMessageBegin
+type storedMessageProtocol struct {
+	TProtocol
+	name   string
+	typeId TMessageType
+	seqid  int32
+}
+
+func NewStoredMessageProtocol(protocol TProtocol, name string, typeId TMessageType, seqid int32) *storedMessageProtocol {
+	return &storedMessageProtocol{protocol, name, typeId, seqid}
+}
+
+func (s *storedMessageProtocol) ReadMessageBegin() (name string, typeId TMessageType, seqid int32, err error) {
+	return s.name, s.typeId, s.seqid, nil
+}