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// Copyright (c) 2016 Martin Atkins
// Permission is hereby granted, free of charge, to any person obtaining a copy of
// this software and associated documentation files (the "Software"), to deal in
// the Software without restriction, including without limitation the rights to
// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
// of the Software, and to permit persons to whom the Software is furnished to do
// so, subject to the following conditions:
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
package demux
import (
"bytes"
"fmt"
"io"
"reflect"
"testing"
)
func TestDemultiplex(t *testing.T) {
type TestCase struct {
Input []string
ExpectedReplies []string
ExpectedEvents []string
}
testCases := []TestCase{
{
Input: []string{},
ExpectedReplies: []string{},
ExpectedEvents: []string{},
},
{
Input: []string{
"SUCCESS: foo bar baz",
},
ExpectedReplies: []string{
"SUCCESS: foo bar baz",
},
ExpectedEvents: []string{},
},
{
Input: []string{
">STATE:1234,ASSIGN_IP,,10.0.0.1,",
},
ExpectedReplies: []string{},
ExpectedEvents: []string{
"STATE:1234,ASSIGN_IP,,10.0.0.1,",
},
},
{
Input: []string{
">STATE:1234,ASSIGN_IP,,10.0.0.1,",
">STATE:5678,ASSIGN_IP,,10.0.0.1,",
">STATE:9012,ASSIGN_IP,,10.0.0.1,",
},
ExpectedReplies: []string{},
ExpectedEvents: []string{
"STATE:1234,ASSIGN_IP,,10.0.0.1,",
"STATE:5678,ASSIGN_IP,,10.0.0.1,",
"STATE:9012,ASSIGN_IP,,10.0.0.1,",
},
},
{
Input: []string{
">STATE:1234,ASSIGN_IP,,10.0.0.1,",
"SUCCESS: foo bar baz",
">STATE:5678,ASSIGN_IP,,10.0.0.1,",
},
ExpectedReplies: []string{
"SUCCESS: foo bar baz",
},
ExpectedEvents: []string{
"STATE:1234,ASSIGN_IP,,10.0.0.1,",
"STATE:5678,ASSIGN_IP,,10.0.0.1,",
},
},
{
Input: []string{
"SUCCESS: foo bar baz",
">STATE:1234,ASSIGN_IP,,10.0.0.1,",
"SUCCESS: baz bar foo",
},
ExpectedReplies: []string{
"SUCCESS: foo bar baz",
"SUCCESS: baz bar foo",
},
ExpectedEvents: []string{
"STATE:1234,ASSIGN_IP,,10.0.0.1,",
},
},
}
for i, testCase := range testCases {
r := mockReader(testCase.Input)
gotReplies, gotEvents := captureMsgs(r)
if !reflect.DeepEqual(gotReplies, testCase.ExpectedReplies) {
t.Errorf(
"test %d returned incorrect replies\ngot %#v\nwant %#v",
i, gotReplies, testCase.ExpectedReplies,
)
}
if !reflect.DeepEqual(gotEvents, testCase.ExpectedEvents) {
t.Errorf(
"test %d returned incorrect events\ngot %#v\nwant %#v",
i, gotEvents, testCase.ExpectedEvents,
)
}
}
}
func TestDemultiplex_error(t *testing.T) {
r := &alwaysErroringReader{}
gotReplies, gotEvents := captureMsgs(r)
expectedReplies := []string{}
expectedEvents := []string{
"FATAL:Error reading from OpenVPN",
}
if !reflect.DeepEqual(gotReplies, expectedReplies) {
t.Errorf(
"incorrect replies\ngot %#v\nwant %#v",
gotReplies, expectedReplies,
)
}
if !reflect.DeepEqual(gotEvents, expectedEvents) {
t.Errorf(
"incorrect events\ngot %#v\nwant %#v",
gotEvents, expectedEvents,
)
}
}
func mockReader(msgs []string) io.Reader {
var buf []byte
for _, msg := range msgs {
buf = append(buf, []byte(msg)...)
buf = append(buf, '\n')
}
return bytes.NewReader(buf)
}
func captureMsgs(r io.Reader) (replies, events []string) {
replyCh := make(chan []byte)
eventCh := make(chan []byte)
replies = make([]string, 0)
events = make([]string, 0)
go Demultiplex(r, replyCh, eventCh)
for replyCh != nil || eventCh != nil {
select {
case msg, ok := <-replyCh:
if ok {
replies = append(replies, string(msg))
} else {
replyCh = nil
}
case msg, ok := <-eventCh:
if ok {
events = append(events, string(msg))
} else {
eventCh = nil
}
}
}
return replies, events
}
type alwaysErroringReader struct{}
func (r *alwaysErroringReader) Read(buf []byte) (int, error) {
return 0, fmt.Errorf("mock error")
}
// Somewhat-contrived example of blocking for a reply while concurrently
// processing asynchronous events.
func ExampleDemultiplex() {
// In a real caller we would have a net.IPConn as our reader,
// but we'll use a bytes reader here as a test.
r := bytes.NewReader([]byte(
// A reply to a hypothetical command interspersed between
// two asynchronous events.
">HOLD:Waiting for hold release\nSUCCESS: foo\n>FATAL:baz\n",
))
// No strong need for buffering on this channel because usually
// a message sender will immediately block waiting for the
// associated response message.
replyCh := make(chan []byte)
// Make sure the event channel buffer is deep enough that slow event
// processing won't significantly delay synchronous replies. If you
// process events quickly, or if you aren't sending any commands
// concurrently with acting on events, then this is not so important.
eventCh := make(chan []byte, 10)
// Start demultiplexing the message stream in the background.
// This goroutine will exit once the reader signals EOF.
go Demultiplex(r, replyCh, eventCh)
// Some coroutine has sent a hypothetical message to OpenVPN,
// and it can directly block until the associated reply arrives.
// The events will be concurrently handled by our event loop
// below while we wait for the reply to show up.
go func() {
replyMsgBuf := <-replyCh
fmt.Printf("Command reply: %s\n", string(replyMsgBuf))
}()
// Main event loop deals with the async events as they arrive,
// independently of any commands that are pending.
for msgBuf := range eventCh {
fmt.Printf("Event: %s\n", string(msgBuf))
}
}
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