Replace the use of bufio.Scanner with bufio.Reader so that requests over 64Kb in size can be replayed from a capture file.

This commit is contained in:
Jon Barber
2016-04-21 10:15:48 +01:00
parent 6c410ab978
commit e659f65d76
4 changed files with 275 additions and 23 deletions
+1
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@@ -11,4 +11,5 @@
*.test
.idea
*.iml
gor
+42 -23
View File
@@ -2,6 +2,8 @@ package main
import (
"bufio"
"bytes"
"io"
"log"
"os"
"strconv"
@@ -53,36 +55,53 @@ func (i *FileInput) String() string {
func (i *FileInput) emit() {
var lastTime int64
// reader := bufio.NewReader(conn)
scanner := bufio.NewScanner(i.file)
scanner.Split(payloadScanner)
payloadSeparatorAsBytes := []byte(payloadSeparator)
reader := bufio.NewReader(i.file)
var buffer bytes.Buffer
for scanner.Scan() {
buf := scanner.Bytes()
meta := payloadMeta(buf)
for {
line, err := reader.ReadBytes('\n')
if len(meta) > 2 && meta[0][0] == RequestPayload {
ts, _ := strconv.ParseInt(string(meta[2]), 10, 64)
if lastTime != 0 {
timeDiff := ts - lastTime
if i.speedFactor != 1 {
timeDiff = int64(float64(timeDiff) / i.speedFactor)
}
time.Sleep(time.Duration(timeDiff))
if err != nil {
if err != io.EOF {
log.Fatal(err)
}
break
lastTime = ts
}
// scanner returs only pointer, so to remove data-race we have to allocate new array
newBuf := make([]byte, len(buf))
copy(newBuf, buf)
if bytes.Equal(payloadSeparatorAsBytes[1:], line) {
asBytes := buffer.Bytes()[:buffer.Len()-1]
buffer.Reset()
meta := payloadMeta(asBytes)
if len(meta) > 2 && meta[0][0] == RequestPayload {
ts, _ := strconv.ParseInt(string(meta[2]), 10, 64)
if lastTime != 0 {
timeDiff := ts - lastTime
if i.speedFactor != 1 {
timeDiff = int64(float64(timeDiff) / i.speedFactor)
}
time.Sleep(time.Duration(timeDiff))
}
lastTime = ts
}
// Bytes() returns only pointer, so to remove data-race copy the data to an array
newBuf := make([]byte, len(asBytes))
copy(newBuf, asBytes)
i.data <- newBuf
} else {
buffer.Write(line)
}
i.data <- newBuf
}
log.Println("FileInput: end of file")
log.Printf("FileInput: end of file '%s'\n", i.path)
}
+220
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@@ -0,0 +1,220 @@
package main
import (
"bytes"
"errors"
"io"
"io/ioutil"
"os"
"sync"
"syscall"
"testing"
"time"
)
func TestInputFileWithGET(t *testing.T) {
input := NewTestInput()
rg := NewRequestGenerator([]io.Reader{input}, func() { input.EmitGET() }, 1)
readPayloads := [][]byte{}
// Given a capture file with a GET request
expectedCaptureFile := CreateCaptureFile(rg)
defer expectedCaptureFile.TearDown()
// When the request is read from the capture file
err := ReadFromCaptureFile(expectedCaptureFile.file, 1, func(data []byte) {
readPayloads = append(readPayloads, Duplicate(data))
})
// The read request should match the original request
if err != nil {
t.Error(err)
} else {
if !expectedCaptureFile.PayloadsEqual(readPayloads) {
t.Error("Request read back from file should match")
}
}
}
func TestInputFileWithPayloadLargerThan64Kb(t *testing.T) {
input := NewTestInput()
rg := NewRequestGenerator([]io.Reader{input}, func() { input.EmitSizedPOST(64 * 1024) }, 1)
readPayloads := [][]byte{}
// Given a capture file with a request over 64Kb
expectedCaptureFile := CreateCaptureFile(rg)
defer expectedCaptureFile.TearDown()
// When the request is read from the capture file
err := ReadFromCaptureFile(expectedCaptureFile.file, 1, func(data []byte) {
readPayloads = append(readPayloads, Duplicate(data))
})
// The read request should match the original request
if err != nil {
t.Error(err)
} else {
if !expectedCaptureFile.PayloadsEqual(readPayloads) {
t.Error("Request read back from file should match")
}
}
}
func TestInputFileWithGETAndPOST(t *testing.T) {
input := NewTestInput()
rg := NewRequestGenerator([]io.Reader{input}, func() {
input.EmitGET()
input.EmitPOST()
}, 2)
readPayloads := [][]byte{}
// Given a capture file with a GET request
expectedCaptureFile := CreateCaptureFile(rg)
defer expectedCaptureFile.TearDown()
// When the requests are read from the capture file
err := ReadFromCaptureFile(expectedCaptureFile.file, 2, func(data []byte) {
readPayloads = append(readPayloads, Duplicate(data))
})
// The read requests should match the original request
if err != nil {
t.Error(err)
} else {
if !expectedCaptureFile.PayloadsEqual(readPayloads) {
t.Error("Request read back from file should match")
}
}
}
type CaptureFile struct {
data [][]byte
file *os.File
}
func NewExpectedCaptureFile(data [][]byte, file *os.File) *CaptureFile {
ecf := new(CaptureFile)
ecf.file = file
ecf.data = data
return ecf
}
func (expectedCaptureFile *CaptureFile) TearDown() {
if expectedCaptureFile.file != nil {
syscall.Unlink(expectedCaptureFile.file.Name())
}
}
type RequestGenerator struct {
inputs []io.Reader
emit func()
wg *sync.WaitGroup
}
func NewRequestGenerator(inputs []io.Reader, emit func(), count int) (rg *RequestGenerator) {
rg = new(RequestGenerator)
rg.inputs = inputs
rg.emit = emit
rg.wg = new(sync.WaitGroup)
rg.wg.Add(count)
return
}
func (expectedCaptureFile *CaptureFile) PayloadsEqual(other [][]byte) bool {
if len(expectedCaptureFile.data) != len(other) {
return false
}
for i, payload := range other {
if !bytes.Equal(expectedCaptureFile.data[i], payload) {
return false
}
}
return true
}
func CreateCaptureFile(requestGenerator *RequestGenerator) *CaptureFile {
f, err := ioutil.TempFile("", "testmainconf")
if err != nil {
panic(err)
}
quit := make(chan int)
readPayloads := [][]byte{}
output := NewTestOutput(func(data []byte) {
readPayloads = append(readPayloads, Duplicate(data))
requestGenerator.wg.Done()
})
outputFile := NewFileOutput(f.Name())
Plugins.Inputs = requestGenerator.inputs
Plugins.Outputs = []io.Writer{output, outputFile}
go Start(quit)
requestGenerator.emit()
requestGenerator.wg.Wait()
close(quit)
return NewExpectedCaptureFile(readPayloads, f)
}
func ReadFromCaptureFile(captureFile *os.File, count int, callback writeCallback) (err error) {
quit := make(chan int)
wg := new(sync.WaitGroup)
input := NewFileInput(captureFile.Name())
output := NewTestOutput(func(data []byte) {
callback(data)
wg.Done()
})
Plugins.Inputs = []io.Reader{input}
Plugins.Outputs = []io.Writer{output}
wg.Add(count)
go Start(quit)
done := make(chan int, 1)
go func() {
wg.Wait()
done <- 1
}()
select {
case <-done:
break
case <-time.After(2 * time.Second):
err = errors.New("Timed out")
}
close(quit)
return
}
func Duplicate(data []byte) (duplicate []byte) {
duplicate = make([]byte, len(data))
copy(duplicate, data)
return
}
+12
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@@ -53,6 +53,18 @@ func (i *TestInput) EmitLargePOST() {
rs := base64.URLEncoding.EncodeToString(rb)
i.data <- []byte("POST / HTTP/1.1\nHost: www.w3.org\nContent-Length:5242880\r\n\r\n" + rs)
Debug("Sent large POST")
}
// EmitSizedPOST emit a POST with a payload set to a supplied size
func (i *TestInput) EmitSizedPOST(payloadSize int) {
rb := make([]byte, payloadSize)
rand.Read(rb)
rs := base64.URLEncoding.EncodeToString(rb)
i.data <- []byte("POST / HTTP/1.1\nHost: www.w3.org\nContent-Length:5242880\r\n\r\n" + rs)
Debug("Sent large POST")
}
// EmitOPTIONS emits OPTIONS request, similar to GET