Initial commit – wire format implementation and some host client commands.

This commit is contained in:
Zach Klippenstein 2015-04-11 14:45:29 -07:00
commit 8d46dec61d
13 changed files with 1013 additions and 0 deletions

201
LICENSE.txt Normal file
View file

@ -0,0 +1,201 @@
Apache License
Version 2.0, January 2004
http://www.apache.org/licenses/
TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
1. Definitions.
"License" shall mean the terms and conditions for use, reproduction,
and distribution as defined by Sections 1 through 9 of this document.
"Licensor" shall mean the copyright owner or entity authorized by
the copyright owner that is granting the License.
"Legal Entity" shall mean the union of the acting entity and all
other entities that control, are controlled by, or are under common
control with that entity. For the purposes of this definition,
"control" means (i) the power, direct or indirect, to cause the
direction or management of such entity, whether by contract or
otherwise, or (ii) ownership of fifty percent (50%) or more of the
outstanding shares, or (iii) beneficial ownership of such entity.
"You" (or "Your") shall mean an individual or Legal Entity
exercising permissions granted by this License.
"Source" form shall mean the preferred form for making modifications,
including but not limited to software source code, documentation
source, and configuration files.
"Object" form shall mean any form resulting from mechanical
transformation or translation of a Source form, including but
not limited to compiled object code, generated documentation,
and conversions to other media types.
"Work" shall mean the work of authorship, whether in Source or
Object form, made available under the License, as indicated by a
copyright notice that is included in or attached to the work
(an example is provided in the Appendix below).
"Derivative Works" shall mean any work, whether in Source or Object
form, that is based on (or derived from) the Work and for which the
editorial revisions, annotations, elaborations, or other modifications
represent, as a whole, an original work of authorship. For the purposes
of this License, Derivative Works shall not include works that remain
separable from, or merely link (or bind by name) to the interfaces of,
the Work and Derivative Works thereof.
"Contribution" shall mean any work of authorship, including
the original version of the Work and any modifications or additions
to that Work or Derivative Works thereof, that is intentionally
submitted to Licensor for inclusion in the Work by the copyright owner
or by an individual or Legal Entity authorized to submit on behalf of
the copyright owner. For the purposes of this definition, "submitted"
means any form of electronic, verbal, or written communication sent
to the Licensor or its representatives, including but not limited to
communication on electronic mailing lists, source code control systems,
and issue tracking systems that are managed by, or on behalf of, the
Licensor for the purpose of discussing and improving the Work, but
excluding communication that is conspicuously marked or otherwise
designated in writing by the copyright owner as "Not a Contribution."
"Contributor" shall mean Licensor and any individual or Legal Entity
on behalf of whom a Contribution has been received by Licensor and
subsequently incorporated within the Work.
2. Grant of Copyright License. Subject to the terms and conditions of
this License, each Contributor hereby grants to You a perpetual,
worldwide, non-exclusive, no-charge, royalty-free, irrevocable
copyright license to reproduce, prepare Derivative Works of,
publicly display, publicly perform, sublicense, and distribute the
Work and such Derivative Works in Source or Object form.
3. Grant of Patent License. Subject to the terms and conditions of
this License, each Contributor hereby grants to You a perpetual,
worldwide, non-exclusive, no-charge, royalty-free, irrevocable
(except as stated in this section) patent license to make, have made,
use, offer to sell, sell, import, and otherwise transfer the Work,
where such license applies only to those patent claims licensable
by such Contributor that are necessarily infringed by their
Contribution(s) alone or by combination of their Contribution(s)
with the Work to which such Contribution(s) was submitted. If You
institute patent litigation against any entity (including a
cross-claim or counterclaim in a lawsuit) alleging that the Work
or a Contribution incorporated within the Work constitutes direct
or contributory patent infringement, then any patent licenses
granted to You under this License for that Work shall terminate
as of the date such litigation is filed.
4. Redistribution. You may reproduce and distribute copies of the
Work or Derivative Works thereof in any medium, with or without
modifications, and in Source or Object form, provided that You
meet the following conditions:
(a) You must give any other recipients of the Work or
Derivative Works a copy of this License; and
(b) You must cause any modified files to carry prominent notices
stating that You changed the files; and
(c) You must retain, in the Source form of any Derivative Works
that You distribute, all copyright, patent, trademark, and
attribution notices from the Source form of the Work,
excluding those notices that do not pertain to any part of
the Derivative Works; and
(d) If the Work includes a "NOTICE" text file as part of its
distribution, then any Derivative Works that You distribute must
include a readable copy of the attribution notices contained
within such NOTICE file, excluding those notices that do not
pertain to any part of the Derivative Works, in at least one
of the following places: within a NOTICE text file distributed
as part of the Derivative Works; within the Source form or
documentation, if provided along with the Derivative Works; or,
within a display generated by the Derivative Works, if and
wherever such third-party notices normally appear. The contents
of the NOTICE file are for informational purposes only and
do not modify the License. You may add Your own attribution
notices within Derivative Works that You distribute, alongside
or as an addendum to the NOTICE text from the Work, provided
that such additional attribution notices cannot be construed
as modifying the License.
You may add Your own copyright statement to Your modifications and
may provide additional or different license terms and conditions
for use, reproduction, or distribution of Your modifications, or
for any such Derivative Works as a whole, provided Your use,
reproduction, and distribution of the Work otherwise complies with
the conditions stated in this License.
5. Submission of Contributions. Unless You explicitly state otherwise,
any Contribution intentionally submitted for inclusion in the Work
by You to the Licensor shall be under the terms and conditions of
this License, without any additional terms or conditions.
Notwithstanding the above, nothing herein shall supersede or modify
the terms of any separate license agreement you may have executed
with Licensor regarding such Contributions.
6. Trademarks. This License does not grant permission to use the trade
names, trademarks, service marks, or product names of the Licensor,
except as required for reasonable and customary use in describing the
origin of the Work and reproducing the content of the NOTICE file.
7. Disclaimer of Warranty. Unless required by applicable law or
agreed to in writing, Licensor provides the Work (and each
Contributor provides its Contributions) on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
implied, including, without limitation, any warranties or conditions
of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
PARTICULAR PURPOSE. You are solely responsible for determining the
appropriateness of using or redistributing the Work and assume any
risks associated with Your exercise of permissions under this License.
8. Limitation of Liability. In no event and under no legal theory,
whether in tort (including negligence), contract, or otherwise,
unless required by applicable law (such as deliberate and grossly
negligent acts) or agreed to in writing, shall any Contributor be
liable to You for damages, including any direct, indirect, special,
incidental, or consequential damages of any character arising as a
result of this License or out of the use or inability to use the
Work (including but not limited to damages for loss of goodwill,
work stoppage, computer failure or malfunction, or any and all
other commercial damages or losses), even if such Contributor
has been advised of the possibility of such damages.
9. Accepting Warranty or Additional Liability. While redistributing
the Work or Derivative Works thereof, You may choose to offer,
and charge a fee for, acceptance of support, warranty, indemnity,
or other liability obligations and/or rights consistent with this
License. However, in accepting such obligations, You may act only
on Your own behalf and on Your sole responsibility, not on behalf
of any other Contributor, and only if You agree to indemnify,
defend, and hold each Contributor harmless for any liability
incurred by, or claims asserted against, such Contributor by reason
of your accepting any such warranty or additional liability.
END OF TERMS AND CONDITIONS
APPENDIX: How to apply the Apache License to your work.
To apply the Apache License to your work, attach the following
boilerplate notice, with the fields enclosed by brackets "{}"
replaced with your own identifying information. (Don't include
the brackets!) The text should be enclosed in the appropriate
comment syntax for the file format. We also recommend that a
file or class name and description of purpose be included on the
same "printed page" as the copyright notice for easier
identification within third-party archives.
Copyright {yyyy} {name of copyright owner}
Licensed 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.

5
README.md Normal file
View file

@ -0,0 +1,5 @@
#goadb
[![GoDoc](https://godoc.org/github.com/zach-klippenstein/goadb?status.svg)](https://godoc.org/github.com/zach-klippenstein/goadb)
A Golang library for interacting with the Android Debug Bridge (adb).

33
cmd/demo/demo.go Normal file
View file

@ -0,0 +1,33 @@
package main
import (
"fmt"
"log"
adb "github.com/zach-klippenstein/goadb"
"github.com/zach-klippenstein/goadb/wire"
)
func main() {
client := &adb.HostClient{wire.Dial}
fmt.Println("Starting server…")
client.StartServer()
serverVersion, err := client.GetServerVersion()
if err != nil {
log.Fatal(err)
}
fmt.Println("Server version:", serverVersion)
devices, err := client.ListDevices()
if err != nil {
log.Fatal(err)
}
fmt.Println("Devices:")
for _, device := range devices {
fmt.Printf("\t%+v\n", *device)
}
fmt.Println("Killing server…")
client.KillServer()
}

78
cmd/raw-adb/raw-adb.go Normal file
View file

@ -0,0 +1,78 @@
package main
import (
"bufio"
"flag"
"fmt"
"io"
"log"
"os"
"strings"
"github.com/zach-klippenstein/goadb/wire"
)
var port = flag.Int("p", wire.AdbPort, "port the adb server is listening on")
func main() {
flag.Parse()
fmt.Println("using port", *port)
printServerVersion()
for {
line := readLine()
err := doCommand(line)
if err != nil {
fmt.Println("error:", err)
}
}
}
func printServerVersion() {
err := doCommand("host:version")
if err != nil {
log.Fatal(err)
}
}
func readLine() string {
fmt.Print("> ")
line, err := bufio.NewReader(os.Stdin).ReadString('\n')
if err != nil && err != io.EOF {
log.Fatal(err)
}
return strings.TrimSpace(line)
}
func doCommand(cmd string) error {
conn, err := wire.DialPort(*port)
if err != nil {
log.Fatal(err)
}
defer conn.Close()
if err := wire.SendMessageString(conn, cmd); err != nil {
return err
}
status, err := conn.ReadStatus()
if err != nil {
return err
}
var msg string
for err == nil {
msg, err = wire.ReadMessageString(conn)
if err == nil {
fmt.Printf("%s> %s\n", status, msg)
}
}
if err != io.EOF {
return err
}
return nil
}

92
devices.go Normal file
View file

@ -0,0 +1,92 @@
package goadb
import (
"bufio"
"fmt"
"strings"
)
// Device represents a connected Android device.
type Device struct {
// Always set.
Serial string
// Product, device, and model are not set in the short form.
Product string
Model string
Device string
// Only set for devices connected via USB.
Usb string
}
// IsUsb returns true if the device is connected via USB.
func (d *Device) IsUsb() bool {
return d.Usb != ""
}
func newDevice(serial string, attrs map[string]string) (*Device, error) {
if serial == "" {
return nil, fmt.Errorf("device serial cannot be blank")
}
return &Device{
Serial: serial,
Product: attrs["product"],
Model: attrs["model"],
Device: attrs["device"],
Usb: attrs["usb"],
}, nil
}
func parseDeviceList(list string, lineParseFunc func(string) (*Device, error)) ([]*Device, error) {
var devices []*Device
scanner := bufio.NewScanner(strings.NewReader(list))
for scanner.Scan() {
device, err := lineParseFunc(scanner.Text())
if err != nil {
return nil, err
}
devices = append(devices, device)
}
if err := scanner.Err(); err != nil {
return nil, err
}
return devices, nil
}
func parseDeviceShort(line string) (*Device, error) {
fields := strings.Fields(line)
if len(fields) != 2 {
return nil, fmt.Errorf("malformed device line, expected 2 fields but found %d", len(fields))
}
return newDevice(fields[0], map[string]string{})
}
func parseDeviceLong(line string) (*Device, error) {
fields := strings.Fields(line)
if len(fields) < 5 {
return nil, fmt.Errorf("malformed device line, expected at least 5 fields but found %d", len(fields))
}
attrs := parseDeviceAttributes(fields[2:])
return newDevice(fields[0], attrs)
}
func parseDeviceAttributes(fields []string) map[string]string {
attrs := map[string]string{}
for _, field := range fields {
key, val := parseKeyVal(field)
attrs[key] = val
}
return attrs
}
// Parses a key:val pair and returns key, val.
func parseKeyVal(pair string) (string, string) {
split := strings.Split(pair, ":")
return split[0], split[1]
}

45
devices_test.go Normal file
View file

@ -0,0 +1,45 @@
package goadb
import (
"testing"
"github.com/stretchr/testify/assert"
)
func ParseDeviceList(t *testing.T) {
devs, err := parseDeviceList(`192.168.56.101:5555 device
05856558`, parseDeviceShort)
assert.NoError(t, err)
assert.Len(t, devs, 2)
assert.Equal(t, "192.168.56.101:5555", devs[0].Serial)
assert.Equal(t, "05856558", devs[1].Serial)
}
func TestParseDeviceShort(t *testing.T) {
dev, err := parseDeviceShort("192.168.56.101:5555 device\n")
assert.NoError(t, err)
assert.Equal(t, &Device{
Serial: "192.168.56.101:5555"}, dev)
}
func TestParseDeviceLong(t *testing.T) {
dev, err := parseDeviceLong("SERIAL device product:PRODUCT model:MODEL device:DEVICE\n")
assert.NoError(t, err)
assert.Equal(t, &Device{
Serial: "SERIAL",
Product: "PRODUCT",
Model: "MODEL",
Device: "DEVICE"}, dev)
}
func TestParseDeviceLongUsb(t *testing.T) {
dev, err := parseDeviceLong("SERIAL device usb:1234 product:PRODUCT model:MODEL device:DEVICE \n")
assert.NoError(t, err)
assert.Equal(t, &Device{
Serial: "SERIAL",
Product: "PRODUCT",
Model: "MODEL",
Device: "DEVICE",
Usb: "1234"}, dev)
}

156
host_client.go Normal file
View file

@ -0,0 +1,156 @@
/*
Go interface to the Android Debug Bridge (adb).
The client/server spec is defined at https://android.googlesource.com/platform/system/core/+/master/adb/OVERVIEW.TXT.
WARNING This library is under heavy development, and its API is likely to change without notice.
*/
package goadb
import (
"fmt"
"os/exec"
"strconv"
"github.com/zach-klippenstein/goadb/wire"
)
// Dialer is a function that knows how to create a connection to an adb server.
type Dialer func() (*wire.Conn, error)
/*
Interacts with host services on the adb server.
Eg.
dialer := &HostClient{wire.Dial}
dialer.GetServerVersion()
TODO make this a real example.
TODO Finish implementing services.
See list of services at https://android.googlesource.com/platform/system/core/+/master/adb/SERVICES.TXT.
*/
type HostClient struct {
Dialer
}
// GetServerVersion asks the ADB server for its internal version number.
func (c *HostClient) GetServerVersion() (int, error) {
resp, err := c.roundTripSingleResponse([]byte("host:version"))
if err != nil {
return 0, err
}
version, err := strconv.ParseInt(string(resp), 16, 32)
return int(version), err
}
/*
KillServer tells the server to quit immediately.
Corresponds to the command:
adb kill-server
*/
func (c *HostClient) KillServer() error {
conn, err := c.Dialer()
if err != nil {
return err
}
defer conn.Close()
if err = conn.SendMessage([]byte("host:kill")); err != nil {
return err
}
return nil
}
/*
StartServer ensures there is a server running.
Currently implemented by just running
adb start-server
*/
func (c *HostClient) StartServer() error {
cmd := exec.Command("adb", "start-server")
return cmd.Run()
}
/*
ListDeviceSerials returns the serial numbers of all attached devices.
Corresponds to the command:
adb devices
*/
func (c *HostClient) ListDeviceSerials() ([]string, error) {
resp, err := c.roundTripSingleResponse([]byte("host:devices"))
if err != nil {
return nil, err
}
devices, err := parseDeviceList(string(resp), parseDeviceShort)
if err != nil {
return nil, err
}
serials := make([]string, len(devices))
for i, dev := range devices {
serials[i] = dev.Serial
}
return serials, nil
}
/*
ListDevices returns the list of connected devices.
Corresponds to the command:
adb devices -l
*/
func (c *HostClient) ListDevices() ([]*Device, error) {
resp, err := c.roundTripSingleResponse([]byte("host:devices-l"))
if err != nil {
return nil, err
}
return parseDeviceList(string(resp), parseDeviceLong)
}
func (c *HostClient) roundTripSingleResponse(req []byte) (resp []byte, err error) {
conn, err := c.Dialer()
if err != nil {
return nil, err
}
defer conn.Close()
if err = conn.SendMessage(req); err != nil {
return nil, err
}
err = c.readStatusFailureAsError(conn)
if err != nil {
return nil, err
}
return conn.ReadMessage()
}
// Reads the status, and if failure, reads the message and returns it as an error.
// If the status is success, doesn't read the message.
func (c *HostClient) readStatusFailureAsError(conn *wire.Conn) error {
status, err := conn.ReadStatus()
if err != nil {
return err
}
if !status.IsSuccess() {
msg, err := conn.ReadMessage()
if err != nil {
return err
}
return fmt.Errorf("server error: %s", msg)
}
return nil
}

54
host_client_test.go Normal file
View file

@ -0,0 +1,54 @@
package goadb
import (
"io"
"testing"
"github.com/stretchr/testify/assert"
"github.com/zach-klippenstein/goadb/wire"
)
func TestGetServerVersion(t *testing.T) {
client := &HostClient{mockDialer(&MockServer{
Status: wire.StatusSuccess,
Messages: []string{"000a"},
})}
v, err := client.GetServerVersion()
assert.NoError(t, err)
assert.Equal(t, 10, v)
}
func mockDialer(s *MockServer) Dialer {
return func() (*wire.Conn, error) {
return &wire.Conn{s, s, s}, nil
}
}
type MockServer struct {
Status wire.StatusCode
Messages []string
nextMsgIndex int
}
func (s *MockServer) ReadStatus() (wire.StatusCode, error) {
return s.Status, nil
}
func (s *MockServer) ReadMessage() ([]byte, error) {
if s.nextMsgIndex >= len(s.Messages) {
return nil, io.EOF
}
s.nextMsgIndex++
return []byte(s.Messages[s.nextMsgIndex-1]), nil
}
func (s *MockServer) SendMessage(msg []byte) error {
return nil
}
func (s *MockServer) Close() error {
return nil
}

69
wire/conn.go Normal file
View file

@ -0,0 +1,69 @@
/*
The wire package implements the low-level part of the client/server wire protocol.
The protocol spec can be found at
https://android.googlesource.com/platform/system/core/+/master/adb/OVERVIEW.TXT.
For most cases, usage looks something like:
conn := wire.Dial()
conn.SendMessage(data)
conn.ReadStatus() == "OKAY" || "FAIL"
conn.ReadMessage()
conn.Close()
For some messages, the server will return more than one message (but still a single
status). Generally, after calling ReadStatus once, you should call ReadMessage until
it returns an io.EOF error.
For most commands, the server will close the connection after sending the response.
You should still always call Close() when you're done with the connection.
*/
package wire
import (
"fmt"
"io"
"net"
)
const (
// Default port the adb server listens on.
AdbPort = 5037
// The official implementation of adb imposes an undocumented 255-byte limit
// on messages.
MaxMessageLength = 255
)
// Conn is a connection to an adb server.
type Conn struct {
Scanner
Sender
io.Closer
}
// Dial connects to the adb server on the default port, AdbPort.
func Dial() (*Conn, error) {
return DialPort(AdbPort)
}
// Dial connects to the adb server on port.
func DialPort(port int) (*Conn, error) {
return DialAddr(fmt.Sprintf("localhost:%d", port))
}
// Dial connects to the adb server at address.
func DialAddr(address string) (*Conn, error) {
netConn, err := net.Dial("tcp", address)
if err != nil {
return nil, err
}
return &Conn{
Scanner: NewScanner(netConn),
Sender: NewSender(netConn),
Closer: netConn,
}, nil
}
var _ io.Closer = &Conn{}

102
wire/scanner.go Normal file
View file

@ -0,0 +1,102 @@
package wire
import (
"fmt"
"io"
"strconv"
)
// StatusCodes are returned by the server. If the code indicates failure, the
// next message will be the error.
type StatusCode string
const (
StatusSuccess StatusCode = "OKAY"
StatusFailure = "FAIL"
StatusNone = ""
)
func (status StatusCode) IsSuccess() bool {
return status == StatusSuccess
}
/*
Scanner reads tokens from a server.
See Conn for more details.
*/
type Scanner interface {
ReadStatus() (StatusCode, error)
ReadMessage() ([]byte, error)
}
type realScanner struct {
reader io.Reader
}
func NewScanner(r io.Reader) Scanner {
return &realScanner{r}
}
func ReadMessageString(s Scanner) (string, error) {
msg, err := s.ReadMessage()
if err != nil {
return string(msg), err
}
return string(msg), nil
}
func (s *realScanner) ReadStatus() (StatusCode, error) {
status := make([]byte, 4)
n, err := io.ReadFull(s.reader, status)
if err != nil && err != io.ErrUnexpectedEOF {
return "", err
} else if err == io.ErrUnexpectedEOF {
return StatusCode(status), incompleteMessage("status", n, 4)
}
return StatusCode(status), nil
}
func (s *realScanner) ReadMessage() ([]byte, error) {
length, err := s.readLength()
if err != nil {
return nil, err
}
data := make([]byte, length)
n, err := io.ReadFull(s.reader, data)
if err != nil && err != io.ErrUnexpectedEOF {
return data, fmt.Errorf("error reading message data: %v", err)
} else if err == io.ErrUnexpectedEOF {
return data, incompleteMessage("message data", n, length)
}
return data, nil
}
func (s *realScanner) readLength() (int, error) {
lengthHex := make([]byte, 4)
n, err := io.ReadFull(s.reader, lengthHex)
if err != nil && err != io.ErrUnexpectedEOF {
return 0, err
} else if err == io.ErrUnexpectedEOF {
return 0, incompleteMessage("length", n, 4)
}
length, err := strconv.ParseInt(string(lengthHex), 16, 64)
if err != nil {
return 0, fmt.Errorf("invalid hex length: %v", err)
}
// Clip the length to 255, as per the Google implementation.
if length > MaxMessageLength {
length = MaxMessageLength
}
return int(length), nil
}
func incompleteMessage(description string, actual int, expected int) error {
return fmt.Errorf("incomplete %s: read %d bytes, expecting %d", description, actual, expected)
}
var _ Scanner = &realScanner{}

106
wire/scanner_test.go Normal file
View file

@ -0,0 +1,106 @@
package wire
import (
"bufio"
"bytes"
"io"
"testing"
"github.com/stretchr/testify/assert"
)
func TestReadStatusOkay(t *testing.T) {
s := NewScannerString("OKAYd")
status, err := s.ReadStatus()
assert.NoError(t, err)
assert.True(t, status.IsSuccess())
assertNotEof(t, s)
}
func TestReadIncompleteStatus(t *testing.T) {
s := NewScannerString("oka")
_, err := s.ReadStatus()
assert.Equal(t, incompleteMessage("status", 3, 4), err)
assertEof(t, s)
}
func TestReadLength(t *testing.T) {
s := NewScannerString("000a")
l, err := s.readLength()
assert.NoError(t, err)
assert.Equal(t, 10, l)
assertEof(t, s)
}
func TestReadIncompleteLength(t *testing.T) {
s := NewScannerString("aaa")
_, err := s.readLength()
assert.Equal(t, incompleteMessage("length", 3, 4), err)
assertEof(t, s)
}
func TestReadMessage(t *testing.T) {
s := NewScannerString("0005hello")
msg, err := ReadMessageString(s)
assert.NoError(t, err)
assert.Len(t, msg, 5)
assert.Equal(t, "hello", msg)
assertEof(t, s)
}
func TestReadMessageWithExtraData(t *testing.T) {
s := NewScannerString("0005hellothere")
msg, err := ReadMessageString(s)
assert.NoError(t, err)
assert.Len(t, msg, 5)
assert.Equal(t, "hello", msg)
assertNotEof(t, s)
}
func TestReadLongerMessage(t *testing.T) {
s := NewScannerString("001b192.168.56.101:5555 device\n")
msg, err := ReadMessageString(s)
assert.NoError(t, err)
assert.Len(t, msg, 27)
assert.Equal(t, "192.168.56.101:5555 device\n", msg)
assertEof(t, s)
}
func TestReadEmptyMessage(t *testing.T) {
s := NewScannerString("0000")
msg, err := ReadMessageString(s)
assert.NoError(t, err)
assert.Equal(t, "", msg)
assertEof(t, s)
}
func TestReadIncompleteMessage(t *testing.T) {
s := NewScannerString("0005hel")
msg, err := ReadMessageString(s)
assert.Error(t, err)
assert.Equal(t, incompleteMessage("message data", 3, 5), err)
assert.Equal(t, "hel\000\000", msg)
assertEof(t, s)
}
func NewScannerString(str string) *realScanner {
return NewScanner(NewEofBuffer(str)).(*realScanner)
}
// NewEofBuffer returns a bytes.Buffer of str that returns an EOF error
// at the end of input, instead of just returning 0 bytes read.
func NewEofBuffer(str string) *bufio.Reader {
return bufio.NewReader(io.LimitReader(bytes.NewBufferString(str), int64(len(str))))
}
func assertEof(t *testing.T, s *realScanner) {
msg, err := s.ReadMessage()
assert.Equal(t, io.EOF, err)
assert.Nil(t, msg)
}
func assertNotEof(t *testing.T, s *realScanner) {
n, err := s.reader.Read(make([]byte, 1))
assert.Equal(t, 1, n)
assert.NoError(t, err)
}

45
wire/sender.go Normal file
View file

@ -0,0 +1,45 @@
package wire
import (
"fmt"
"io"
)
// Sender sends messages to the server.
type Sender interface {
SendMessage(msg []byte) error
}
type realSender struct {
writer io.Writer
}
func NewSender(w io.Writer) Sender {
return &realSender{w}
}
func SendMessageString(s Sender, msg string) error {
return s.SendMessage([]byte(msg))
}
func (s *realSender) SendMessage(msg []byte) error {
if len(msg) > MaxMessageLength {
return fmt.Errorf("message length exceeds maximum: %d", len(msg))
}
lengthAndMsg := fmt.Sprintf("%04x%s", len(msg), msg)
return writeFully(s.writer, []byte(lengthAndMsg))
}
func writeFully(w io.Writer, data []byte) error {
for len(data) > 0 {
n, err := w.Write(data)
if err != nil {
return err
}
data = data[n:]
}
return nil
}
var _ Sender = &realSender{}

27
wire/sender_test.go Normal file
View file

@ -0,0 +1,27 @@
package wire
import (
"bytes"
"testing"
"github.com/stretchr/testify/assert"
)
func TestWriteMessage(t *testing.T) {
s, b := NewTestSender()
err := SendMessageString(s, "hello")
assert.NoError(t, err)
assert.Equal(t, "0005hello", b.String())
}
func TestWriteEmptyMessage(t *testing.T) {
s, b := NewTestSender()
err := SendMessageString(s, "")
assert.NoError(t, err)
assert.Equal(t, "0000", b.String())
}
func NewTestSender() (Sender, *bytes.Buffer) {
var buf bytes.Buffer
return NewSender(&buf), &buf
}