Merge pull request #171 from buger/code-styling

Improve code documentation and styling

.travis.yml

@@ -1,3 +1,3 @@
-language: go 
+language: go
 go: 1.4.2
-script: sudo -E bash -c "source /etc/profile && eval '$(gimme 1.4)' && export GOPATH=$HOME/gopath:$GOPATH && go get && GORACE='halt_on_error=1' go test -race -v"
+script: sudo -E bash -c "source /etc/profile && eval '$(gimme 1.4.2)' && export GOPATH=$HOME/gopath:$GOPATH && go get && GORACE='halt_on_error=1' go test -v"

Makefile

@@ -14,7 +14,7 @@ dbuild:
 	docker build -t gor .
 
 dlint:
-	docker run -v `pwd`:$(SOURCE_PATH) -t -i --env GORACE="halt_on_error=1" gor golint $(ARGS)
+	docker run -v `pwd`:$(SOURCE_PATH) -t -i --env GORACE="halt_on_error=1" gor golint $(PKG)
 
 drace:
 	docker run -v `pwd`:$(SOURCE_PATH) -t -i --env GORACE="halt_on_error=1" gor go test ./... $(ARGS) -v -race -timeout 15s

byteutils/byteutils.go

@@ -1,5 +1,7 @@
+// Package byteutils probvides helpers for working with byte slices
 package byteutils
 
+// Cut elements from slice for a given range
 func Cut(a []byte, from, to int) []byte {
 	copy(a[from:], a[to:])
 	a = a[:len(a)-to+from]
@@ -7,6 +9,7 @@ func Cut(a []byte, from, to int) []byte {
 	return a
 }
 
+// Insert new slice at specified position
 func Insert(a []byte, i int, b []byte) []byte {
 	a = append(a, make([]byte, len(b))...)
 	copy(a[i+len(b):], a[i:])
@@ -15,7 +18,7 @@ func Insert(a []byte, i int, b []byte) []byte {
 	return a
 }
 
-// Unlike bytes.Replace it allows you to specify range
+// Replace function unlike bytes.Replace allows you to specify range
 func Replace(a []byte, from, to int, new []byte) []byte {
 	lenDiff := len(new) - (to - from)
 

elasticsearch.go

@@ -122,24 +122,24 @@ func (p *ESPlugin) ResponseAnalyze(req, resp []byte, start, stop time.Time) {
 	esResp := ESRequestResponse{
 		ReqUrl:               proto.Path(req),
 		ReqMethod:            proto.Method(req),
-		ReqUserAgent:         proto.GetHeader(req, "User-Agent"),
-		ReqAcceptLanguage:    proto.GetHeader(req, "Accept-Language"),
-		ReqAccept:            proto.GetHeader(req, "Accept"),
-		ReqAcceptEncoding:    proto.GetHeader(req, "Accept-Encoding"),
-		ReqIfModifiedSince:   proto.GetHeader(req, "If-Modified-Since"),
-		ReqConnection:        proto.GetHeader(req, "Connection"),
-		ReqCookies:           proto.GetHeader(req, "Cookie"),
+		ReqUserAgent:         proto.Header(req, []byte("User-Agent")),
+		ReqAcceptLanguage:    proto.Header(req, []byte("Accept-Language")),
+		ReqAccept:            proto.Header(req, []byte("Accept")),
+		ReqAcceptEncoding:    proto.Header(req, []byte("Accept-Encoding")),
+		ReqIfModifiedSince:   proto.Header(req, []byte("If-Modified-Since")),
+		ReqConnection:        proto.Header(req, []byte("Connection")),
+		ReqCookies:           proto.Header(req, []byte("Cookie")),
 		RespStatus:           proto.Status(resp),
 		RespStatusCode:       proto.Status(resp),
 		RespProto:            proto.Method(resp),
-		RespContentLength:    proto.GetHeader(resp, "Content-Length"),
-		RespContentType:      proto.GetHeader(resp, "Content-Type"),
-		RespTransferEncoding: proto.GetHeader(resp, "Transfer-Encoding"),
-		RespContentEncoding:  proto.GetHeader(resp, "Content-Encoding"),
-		RespExpires:          proto.GetHeader(resp, "Expires"),
-		RespCacheControl:     proto.GetHeader(resp, "Cache-Control"),
-		RespVary:             proto.GetHeader(resp, "Vary"),
-		RespSetCookie:        proto.GetHeader(resp, "Set-Cookie"),
+		RespContentLength:    proto.Header(resp, []byte("Content-Length")),
+		RespContentType:      proto.Header(resp, []byte("Content-Type")),
+		RespTransferEncoding: proto.Header(resp, []byte("Transfer-Encoding")),
+		RespContentEncoding:  proto.Header(resp, []byte("Content-Encoding")),
+		RespExpires:          proto.Header(resp, []byte("Expires")),
+		RespCacheControl:     proto.Header(resp, []byte("Cache-Control")),
+		RespVary:             proto.Header(resp, []byte("Vary")),
+		RespSetCookie:        proto.Header(resp, []byte("Set-Cookie")),
 		Rtt:                  rtt,
 		Timestamp:            t,
 	}

emitter.go

@@ -5,6 +5,7 @@ import (
 	"time"
 )
 
+// Start initialize loop for sending data from inputs to outputs
 func Start(stop chan int) {
 	for _, in := range Plugins.Inputs {
 		go CopyMulty(in, Plugins.Outputs...)
@@ -19,7 +20,7 @@ func Start(stop chan int) {
 	}
 }
 
-// Copy from 1 reader to multiple writers
+// CopyMulty copies from 1 reader to multiple writers
 func CopyMulty(src io.Reader, writers ...io.Writer) (err error) {
 	buf := make([]byte, 5*1024*1024)
 	wIndex := 0

gor.go

@@ -7,9 +7,9 @@ import (
 	"fmt"
 	"log"
 	"os"
+	"runtime"
 	"runtime/debug"
 	"runtime/pprof"
-	"runtime"
 	"time"
 )
 

http_client.go

@@ -145,9 +145,9 @@ func (c *HTTPClient) Send(data []byte) (response []byte, err error) {
 
 		// 3xx requests
 		if status[0] == '3' {
-			c.redirectsCount += 1
+			c.redirectsCount++
 
-			location, _, _, _ := proto.Header(payload, []byte("Location"))
+			location := proto.Header(payload, []byte("Location"))
 			redirectPayload := []byte("GET " + string(location) + " HTTP/1.1\r\n\r\n")
 
 			if c.config.Debug {
@@ -167,4 +167,4 @@ func (c *HTTPClient) Get(path string) (response []byte, err error) {
 	payload := "GET " + path + " HTTP/1.1\r\n\r\n"
 
 	return c.Send([]byte(payload))
-}
+}

http_client_test.go

@@ -132,7 +132,7 @@ func TestHTTPClientHTTPSSend(t *testing.T) {
 func TestHTTPClientServerInstantDisconnect(t *testing.T) {
 	wg := new(sync.WaitGroup)
 
-	GET_payload := []byte("GET / HTTP/1.1\r\n\r\n")
+	GETPayload := []byte("GET / HTTP/1.1\r\n\r\n")
 
 	ln, _ := net.Listen("tcp", ":0")
 
@@ -148,8 +148,8 @@ func TestHTTPClientServerInstantDisconnect(t *testing.T) {
 	client := NewHTTPClient(ln.Addr().String(), &HTTPClientConfig{})
 
 	wg.Add(2)
-	client.Send(GET_payload)
-	client.Send(GET_payload)
+	client.Send(GETPayload)
+	client.Send(GETPayload)
 
 	wg.Wait()
 }
@@ -157,7 +157,7 @@ func TestHTTPClientServerInstantDisconnect(t *testing.T) {
 func TestHTTPClientServerNoKeepAlive(t *testing.T) {
 	wg := new(sync.WaitGroup)
 
-	GET_payload := []byte("GET / HTTP/1.1\r\n\r\n")
+	GETPayload := []byte("GET / HTTP/1.1\r\n\r\n")
 
 	ln, _ := net.Listen("tcp", ":0")
 
@@ -186,8 +186,8 @@ func TestHTTPClientServerNoKeepAlive(t *testing.T) {
 	client := NewHTTPClient(ln.Addr().String(), &HTTPClientConfig{})
 
 	wg.Add(2)
-	client.Send(GET_payload)
-	client.Send(GET_payload)
+	client.Send(GETPayload)
+	client.Send(GETPayload)
 
 	wg.Wait()
 }
@@ -195,7 +195,7 @@ func TestHTTPClientServerNoKeepAlive(t *testing.T) {
 func TestHTTPClientRedirect(t *testing.T) {
 	wg := new(sync.WaitGroup)
 
-	GET_payload := []byte("GET / HTTP/1.1\r\n\r\n")
+	GETPayload := []byte("GET / HTTP/1.1\r\n\r\n")
 
 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 
@@ -210,7 +210,7 @@ func TestHTTPClientRedirect(t *testing.T) {
 
 	// Should do 2 queries
 	wg.Add(2)
-	client.Send(GET_payload)
+	client.Send(GETPayload)
 
 	wg.Wait()
 }
@@ -218,7 +218,7 @@ func TestHTTPClientRedirect(t *testing.T) {
 func TestHTTPClientRedirectLimit(t *testing.T) {
 	wg := new(sync.WaitGroup)
 
-	GET_payload := []byte("GET / HTTP/1.1\r\n\r\n")
+	GETPayload := []byte("GET / HTTP/1.1\r\n\r\n")
 
 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 
@@ -241,7 +241,7 @@ func TestHTTPClientRedirectLimit(t *testing.T) {
 
 	// Have 3 redirects + 1 GET, but should do only 2 redirects + GET
 	wg.Add(3)
-	client.Send(GET_payload)
+	client.Send(GETPayload)
 
 	wg.Wait()
 }
@@ -249,7 +249,7 @@ func TestHTTPClientRedirectLimit(t *testing.T) {
 func TestHTTPClientHandleHTTP10(t *testing.T) {
 	wg := new(sync.WaitGroup)
 
-	GET_payload := []byte("GET http://foobar.com/path HTTP/1.0\r\n\r\n")
+	GETPayload := []byte("GET http://foobar.com/path HTTP/1.0\r\n\r\n")
 
 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 
@@ -263,7 +263,7 @@ func TestHTTPClientHandleHTTP10(t *testing.T) {
 	client := NewHTTPClient(server.URL, &HTTPClientConfig{Debug: true})
 
 	wg.Add(1)
-	client.Send(GET_payload)
+	client.Send(GETPayload)
 
 	wg.Wait()
 }

http_modifier.go

@@ -88,9 +88,9 @@ func (m *HTTPModifier) Rewrite(payload []byte) (response []byte) {
 
 	if len(m.config.headerFilters) > 0 {
 		for _, f := range m.config.headerFilters {
-			value, s, _, _ := proto.Header(payload, f.name)
+			value := proto.Header(payload, f.name)
 
-			if s != -1 && !f.regexp.Match(value) {
+			if len(value) > 0 && !f.regexp.Match(value) {
 				return
 			}
 		}
@@ -108,9 +108,9 @@ func (m *HTTPModifier) Rewrite(payload []byte) (response []byte) {
 
 	if len(m.config.headerHashFilters) > 0 {
 		for _, f := range m.config.headerHashFilters {
-			value, s, _, _ := proto.Header(payload, f.name)
+			value := proto.Header(payload, f.name)
 
-			if s != -1 {
+			if len(value) > 0 {
 				hasher := fnv.New32a()
 				hasher.Write(value)
 

http_modifier_settings.go

@@ -8,6 +8,7 @@ import (
 	"strings"
 )
 
+// HTTPModifierConfig holds configuration options for built-in traffic modifier
 type HTTPModifierConfig struct {
 	urlNegativeRegexp     HTTPUrlRegexp
 	urlRegexp             HTTPUrlRegexp
@@ -30,6 +31,7 @@ type headerFilter struct {
 	regexp *regexp.Regexp
 }
 
+// HTTPHeaderFilters holds list of headers and their regexps
 type HTTPHeaderFilters []headerFilter
 
 func (h *HTTPHeaderFilters) String() string {
@@ -68,7 +70,7 @@ func (h *HTTPHashFilters) String() string {
 func (h *HTTPHashFilters) Set(value string) error {
 	valArr := strings.SplitN(value, ":", 2)
 	if len(valArr) < 2 {
-		return errors.New("need both header and value, colon-delimited (ex. user_id:50%).")
+		return errors.New("need both header and value, colon-delimited (ex. user_id:50%)")
 	}
 
 	f := hashFilter{name: []byte(valArr[0])}
@@ -181,7 +183,7 @@ func (r *UrlRewriteMap) String() string {
 func (r *UrlRewriteMap) Set(value string) error {
 	valArr := strings.SplitN(value, ":", 2)
 	if len(valArr) < 2 {
-		return errors.New("need both src and target, colon-delimited (ex. /a:/b).")
+		return errors.New("need both src and target, colon-delimited (ex. /a:/b)")
 	}
 	regexp, err := regexp.Compile(valArr[0])
 	if err != nil {

http_modifier_test.go

@@ -67,7 +67,7 @@ func TestHTTPModifierHeaderNegativeFilters(t *testing.T) {
 }
 
 func TestHTTPModifierURLRewrite(t *testing.T) {
-	var url, new_url []byte
+	var url, newURL []byte
 
 	rewrites := UrlRewriteMap{}
 
@@ -85,13 +85,13 @@ func TestHTTPModifierURLRewrite(t *testing.T) {
 	})
 
 	url = []byte("/v1/user/joe/ping")
-	if new_url = proto.Path(modifier.Rewrite(payload(url))); bytes.Equal(new_url, url) {
-		t.Error("Request url should have been rewritten, wasn't", string(new_url))
+	if newURL = proto.Path(modifier.Rewrite(payload(url))); bytes.Equal(newURL, url) {
+		t.Error("Request url should have been rewritten, wasn't", string(newURL))
 	}
 
 	url = []byte("/v1/user/ping")
-	if new_url = proto.Path(modifier.Rewrite(payload(url))); !bytes.Equal(new_url, url) {
-		t.Error("Request url should have been rewritten, wasn't", string(new_url))
+	if newURL = proto.Path(modifier.Rewrite(payload(url))); !bytes.Equal(newURL, url) {
+		t.Error("Request url should have been rewritten, wasn't", string(newURL))
 	}
 }
 
@@ -155,9 +155,9 @@ func TestHTTPModifierHeaders(t *testing.T) {
 	})
 
 	payload := []byte("POST /post HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
-	new_payload := []byte("POST /post HTTP/1.1\r\nHeader1: 1\r\nContent-Length: 7\r\nHost: localhost\r\n\r\na=1&b=2")
+	newPayload := []byte("POST /post HTTP/1.1\r\nHeader1: 1\r\nContent-Length: 7\r\nHost: localhost\r\n\r\na=1&b=2")
 
-	if payload = modifier.Rewrite(payload); !bytes.Equal(payload, new_payload) {
+	if payload = modifier.Rewrite(payload); !bytes.Equal(payload, newPayload) {
 		t.Error("Should update request headers", string(payload))
 	}
 }
@@ -223,9 +223,9 @@ func TestHTTPModifierSetHeader(t *testing.T) {
 	})
 
 	payload := []byte("POST /post HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
-	payload_after := []byte("POST /post HTTP/1.1\r\nUser-Agent: Gor\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	payloadAfter := []byte("POST /post HTTP/1.1\r\nUser-Agent: Gor\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
 
-	if payload = modifier.Rewrite(payload); !bytes.Equal(payload_after, payload) {
+	if payload = modifier.Rewrite(payload); !bytes.Equal(payloadAfter, payload) {
 		t.Error("Should add new header", string(payload))
 	}
 }
@@ -239,9 +239,9 @@ func TestHTTPModifierSetParam(t *testing.T) {
 	})
 
 	payload := []byte("POST /post?api_key=1234 HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
-	payload_after := []byte("POST /post?api_key=1 HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	payloadAfter := []byte("POST /post?api_key=1 HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
 
-	if payload = modifier.Rewrite(payload); !bytes.Equal(payload_after, payload) {
+	if payload = modifier.Rewrite(payload); !bytes.Equal(payloadAfter, payload) {
 		t.Error("Should override param", string(payload))
 	}
 }

input_dummy.go

@@ -4,10 +4,12 @@ import (
 	"time"
 )
 
+// DummyInput used for debugging. It generate 1 "GET /"" request per second.
 type DummyInput struct {
 	data chan []byte
 }
 
+// NewDummyInput constructor for DummyInput
 func NewDummyInput(options string) (di *DummyInput) {
 	di = new(DummyInput)
 	di.data = make(chan []byte)

input_file.go

@@ -7,6 +7,7 @@ import (
 	"time"
 )
 
+// FileInput can read requests generated by FileOutput
 type FileInput struct {
 	data        chan []byte
 	path        string
@@ -14,19 +15,20 @@ type FileInput struct {
 	speedFactor float64
 }
 
+// NewFileInput constructor for FileInput. Accepts file path as argument.
 func NewFileInput(path string) (i *FileInput) {
 	i = new(FileInput)
 	i.data = make(chan []byte)
 	i.path = path
 	i.speedFactor = 1
-	i.Init(path)
+	i.init(path)
 
 	go i.emit()
 
 	return
 }
 
-func (i *FileInput) Init(path string) {
+func (i *FileInput) init(path string) {
 	file, err := os.Open(path)
 
 	if err != nil {

input_http.go

@@ -7,12 +7,14 @@ import (
 	"net/http/httputil"
 )
 
+// HTTPInput used for sending requests to Gor via http
 type HTTPInput struct {
 	data     chan []byte
 	address  string
 	listener net.Listener
 }
 
+// NewHTTPInput constructor for HTTPInput. Accepts address with port which he will listen on.
 func NewHTTPInput(address string) (i *HTTPInput) {
 	i = new(HTTPInput)
 	i.data = make(chan []byte)

input_raw.go

@@ -7,11 +7,13 @@ import (
 	"strings"
 )
 
+// RAWInput used for intercepting traffic for given address
 type RAWInput struct {
 	data    chan []byte
 	address string
 }
 
+// NewRAWInput constructor for RAWInput. Accepts address with port as argument.
 func NewRAWInput(address string) (i *RAWInput) {
 	i = new(RAWInput)
 	i.data = make(chan []byte)

input_raw_test.go

@@ -31,7 +31,7 @@ func TestRAWInput(t *testing.T) {
 
 	address := strings.Replace(listener.Addr().String(), "[::]", "127.0.0.1", -1)
 
-	client := NewHTTPClient(address,  &HTTPClientConfig{})
+	client := NewHTTPClient(address, &HTTPClientConfig{})
 
 	go Start(quit)
 
@@ -49,7 +49,7 @@ func TestInputRAW100Expect(t *testing.T) {
 	wg := new(sync.WaitGroup)
 	quit := make(chan int)
 
-	file_content, _ := ioutil.ReadFile("README.md")
+	fileContent, _ := ioutil.ReadFile("README.md")
 
 	// Origing and Replay server initialization
 	origin := startHTTP(func(req *http.Request) {
@@ -59,12 +59,12 @@ func TestInputRAW100Expect(t *testing.T) {
 		wg.Done()
 	})
 
-	origin_address := strings.Replace(origin.Addr().String(), "[::]", "127.0.0.1", -1)
+	originAddr := strings.Replace(origin.Addr().String(), "[::]", "127.0.0.1", -1)
 
-	input := NewRAWInput(origin_address)
+	input := NewRAWInput(originAddr)
 
 	// We will use it to get content of raw HTTP request
-	test_output := NewTestOutput(func(data []byte) {
+	testOutput := NewTestOutput(func(data []byte) {
 		if strings.Contains(string(data), "Expect: 100-continue") {
 			t.Error("Should not contain 100-continue header")
 		}
@@ -75,24 +75,24 @@ func TestInputRAW100Expect(t *testing.T) {
 		defer req.Body.Close()
 		body, _ := ioutil.ReadAll(req.Body)
 
-		if !bytes.Equal(body, file_content) {
+		if !bytes.Equal(body, fileContent) {
 			buf, _ := httputil.DumpRequest(req, true)
 			t.Error("Wrong POST body:", string(buf))
 		}
 
 		wg.Done()
 	})
-	replay_address := listener.Addr().String()
+	replayAddr := listener.Addr().String()
 
-	http_output := NewHTTPOutput(replay_address, &HTTPOutputConfig{})
+	httpOutput := NewHTTPOutput(replayAddr, &HTTPOutputConfig{})
 
 	Plugins.Inputs = []io.Reader{input}
-	Plugins.Outputs = []io.Writer{test_output, http_output}
+	Plugins.Outputs = []io.Writer{testOutput, httpOutput}
 
 	go Start(quit)
 
 	wg.Add(3)
-	curl := exec.Command("curl", "http://"+origin_address, "--data-binary", "@README.md")
+	curl := exec.Command("curl", "http://"+originAddr, "--data-binary", "@README.md")
 	err := curl.Run()
 	if err != nil {
 		log.Fatal(err)
@@ -106,7 +106,7 @@ func TestInputRAWChunkedEncoding(t *testing.T) {
 	wg := new(sync.WaitGroup)
 	quit := make(chan int)
 
-	file_content, _ := ioutil.ReadFile("README.md")
+	fileContent, _ := ioutil.ReadFile("README.md")
 
 	// Origing and Replay server initialization
 	origin := startHTTP(func(req *http.Request) {
@@ -116,33 +116,33 @@ func TestInputRAWChunkedEncoding(t *testing.T) {
 		wg.Done()
 	})
 
-	origin_address := strings.Replace(origin.Addr().String(), "[::]", "127.0.0.1", -1)
+	originAddr := strings.Replace(origin.Addr().String(), "[::]", "127.0.0.1", -1)
 
-	input := NewRAWInput(origin_address)
+	input := NewRAWInput(originAddr)
 
 	listener := startHTTP(func(req *http.Request) {
 		defer req.Body.Close()
 		body, _ := ioutil.ReadAll(req.Body)
 
-		if !bytes.Equal(body, file_content) {
+		if !bytes.Equal(body, fileContent) {
 			buf, _ := httputil.DumpRequest(req, true)
 			t.Error("Wrong POST body:", string(buf))
 		}
 
 		wg.Done()
 	})
-	replay_address := listener.Addr().String()
+	replayAddr := listener.Addr().String()
 
-	http_output := NewHTTPOutput(replay_address, &HTTPOutputConfig{Debug: true})
+	httpOutput := NewHTTPOutput(replayAddr, &HTTPOutputConfig{Debug: true})
 
 	Plugins.Inputs = []io.Reader{input}
-	Plugins.Outputs = []io.Writer{http_output}
+	Plugins.Outputs = []io.Writer{httpOutput}
 
 	go Start(quit)
 
 	wg.Add(2)
 
-	curl := exec.Command("curl", "http://"+origin_address, "--header", "Transfer-Encoding: chunked", "--data-binary", "@README.md")
+	curl := exec.Command("curl", "http://"+originAddr, "--header", "Transfer-Encoding: chunked", "--data-binary", "@README.md")
 	err := curl.Run()
 	if err != nil {
 		log.Fatal(err)
@@ -175,9 +175,9 @@ func TestInputRAWLargePayload(t *testing.T) {
 
 		wg.Done()
 	})
-	origin_address := strings.Replace(origin.Addr().String(), "[::]", "127.0.0.1", -1)
+	originAddr := strings.Replace(origin.Addr().String(), "[::]", "127.0.0.1", -1)
 
-	input := NewRAWInput(origin_address)
+	input := NewRAWInput(originAddr)
 
 	replay := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
 		req.Body = http.MaxBytesReader(w, req.Body, 1*1024*1024)
@@ -193,15 +193,15 @@ func TestInputRAWLargePayload(t *testing.T) {
 	}))
 	defer replay.Close()
 
-	http_output := NewHTTPOutput(replay.URL, &HTTPOutputConfig{Debug: false})
+	httpOutput := NewHTTPOutput(replay.URL, &HTTPOutputConfig{Debug: false})
 
 	Plugins.Inputs = []io.Reader{input}
-	Plugins.Outputs = []io.Writer{http_output}
+	Plugins.Outputs = []io.Writer{httpOutput}
 
 	go Start(quit)
 
 	wg.Add(2)
-	curl := exec.Command("curl", "http://"+origin_address, "--header", "Transfer-Encoding: chunked", "--data-binary", "@/tmp/large")
+	curl := exec.Command("curl", "http://"+originAddr, "--header", "Transfer-Encoding: chunked", "--data-binary", "@/tmp/large")
 	err = curl.Run()
 	if err != nil {
 		log.Fatal("curl error:", err)

input_tcp.go

@@ -9,15 +9,15 @@ import (
 	"os"
 )
 
-// Can be tested using nc tool:
-//    echo "asdad" | nc 127.0.0.1 27017
-//
+// TCPInput used for internal communication
+// It expected hex encoded data
 type TCPInput struct {
 	data     chan []byte
 	address  string
 	listener net.Listener
 }
 
+// NewTCPInput constructor for TCPInput, accepts address with port
 func NewTCPInput(address string) (i *TCPInput) {
 	i = new(TCPInput)
 	i.data = make(chan []byte)

input_tcp_test.go

@@ -83,10 +83,10 @@ func BenchmarkTCPInput(b *testing.B) {
 			for {
 				data := <-dataChan
 
-				new_buf := make([]byte, len(data)+2)
+				buf := make([]byte, len(data)+2)
 				data = append(data, []byte("¶")...)
-				copy(new_buf, data)
-				conn.Write(new_buf)
+				copy(buf, data)
+				conn.Write(buf)
 			}
 		}(conn)
 	}

limiter.go

@@ -9,6 +9,7 @@ import (
 	"time"
 )
 
+// Limiter is a wrapper for input or output plugin which adds rate limiting
 type Limiter struct {
 	plugin    interface{}
 	limit     int
@@ -30,6 +31,8 @@ func parseLimitOptions(options string) (limit int, isPercent bool) {
 	return
 }
 
+// NewLimiter constructor for Limiter, accepts plugin and options
+// `options` allow to sprcify relatve or absolute limiting
 func NewLimiter(plugin interface{}, options string) io.ReadWriter {
 	l := new(Limiter)
 	l.limit, l.isPercent = parseLimitOptions(options)

output_dummy.go

@@ -4,9 +4,11 @@ import (
 	"fmt"
 )
 
+// DummyOutput used for debugging, prints all incoming requests
 type DummyOutput struct {
 }
 
+// NewDummyOutput constructor for DummyOutput
 func NewDummyOutput(options string) (di *DummyOutput) {
 	di = new(DummyOutput)
 

output_file.go

@@ -8,26 +8,30 @@ import (
 	"time"
 )
 
+// RawRequest stores original start time and request payload
 type RawRequest struct {
 	Timestamp int64
 	Request   []byte
 }
 
+// FileOutput output plugin
 type FileOutput struct {
 	path    string
 	encoder *gob.Encoder
 	file    *os.File
 }
 
+
+// NewFileOutput constructor for FileOutput, accepts path
 func NewFileOutput(path string) io.Writer {
 	o := new(FileOutput)
 	o.path = path
-	o.Init(path)
+	o.init(path)
 
 	return o
 }
 
-func (o *FileOutput) Init(path string) {
+func (o *FileOutput) init(path string) {
 	var err error
 
 	o.file, err = os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0660)

output_http.go

@@ -7,8 +7,9 @@ import (
 	"time"
 )
 
-const InitialDynamicWorkers = 10
+const initialDynamicWorkers = 10
 
+// HTTPOutputConfig struct for holding http output configuration
 type HTTPOutputConfig struct {
 	redirectLimit int
 
@@ -20,6 +21,9 @@ type HTTPOutputConfig struct {
 	Debug bool
 }
 
+// HTTPOutput plugin manage pool of workers which send request to replayed server
+// By default workers pool is dynamic and starts with 10 workers
+// You can specify fixed number of workers using `--output-http-workers`
 type HTTPOutput struct {
 	// Keep this as first element of struct because it guarantees 64bit
 	// alignment. atomic.* functions crash on 32bit machines if operand is not
@@ -39,6 +43,8 @@ type HTTPOutput struct {
 	elasticSearch *ESPlugin
 }
 
+// NewHTTPOutput constructor for HTTPOutput
+// Initialize workers
 func NewHTTPOutput(address string, config *HTTPOutputConfig) io.Writer {
 
 	o := new(HTTPOutput)
@@ -55,7 +61,7 @@ func NewHTTPOutput(address string, config *HTTPOutputConfig) io.Writer {
 
 	// Initial workers count
 	if o.config.workers == 0 {
-		o.needWorker <- InitialDynamicWorkers
+		o.needWorker <- initialDynamicWorkers
 	} else {
 		o.needWorker <- o.config.workers
 	}
@@ -65,16 +71,16 @@ func NewHTTPOutput(address string, config *HTTPOutputConfig) io.Writer {
 		o.elasticSearch.Init(o.config.elasticSearch)
 	}
 
-	go o.WorkerMaster()
+	go o.workerMaster()
 
 	return o
 }
 
-func (o *HTTPOutput) WorkerMaster() {
+func (o *HTTPOutput) workerMaster() {
 	for {
-		new_workers := <-o.needWorker
-		for i := 0; i < new_workers; i++ {
-			go o.Worker()
+		newWorkers := <-o.needWorker
+		for i := 0; i < newWorkers; i++ {
+			go o.startWorker()
 		}
 
 		// Disable dynamic scaling if workers poll fixed size
@@ -84,13 +90,13 @@ func (o *HTTPOutput) WorkerMaster() {
 	}
 }
 
-func (o *HTTPOutput) Worker() {
+func (o *HTTPOutput) startWorker() {
 	client := NewHTTPClient(o.address, &HTTPClientConfig{
 		FollowRedirects: o.config.redirectLimit,
 		Debug:           o.config.Debug,
 	})
 
-	death_count := 0
+	deathCount := 0
 
 	atomic.AddInt64(&o.activeWorkers, 1)
 
@@ -98,19 +104,19 @@ func (o *HTTPOutput) Worker() {
 		select {
 		case data := <-o.queue:
 			o.sendRequest(client, data)
-			death_count = 0
+			deathCount = 0
 		case <-time.After(time.Millisecond * 100):
 			// When dynamic scaling enabled workers die after 2s of inactivity
 			if o.config.workers == 0 {
-				death_count += 1
+				deathCount++
 			} else {
 				continue
 			}
 
-			if death_count > 20 {
+			if deathCount > 20 {
 				workersCount := atomic.LoadInt64(&o.activeWorkers)
 
-				// At least 1 worker should be alive
+				// At least 1 startWorker should be alive
 				if workersCount != 1 {
 					atomic.AddInt64(&o.activeWorkers, -1)
 					return

output_http_test.go

@@ -86,10 +86,10 @@ func TestOutputHTTPSSL(t *testing.T) {
 	}))
 
 	input := NewTestInput()
-	http_output := NewHTTPOutput(server.URL, &HTTPOutputConfig{})
+	output := NewHTTPOutput(server.URL, &HTTPOutputConfig{})
 
 	Plugins.Inputs = []io.Reader{input}
-	Plugins.Outputs = []io.Writer{http_output}
+	Plugins.Outputs = []io.Writer{output}
 
 	go Start(quit)
 

output_tcp.go

@@ -9,6 +9,9 @@ import (
 	"time"
 )
 
+// TCPOutput used for sending raw tcp payloads
+// Currently used for internal communication between listener and replay server
+// Can be used for transfering binary payloads like protocol buffers
 type TCPOutput struct {
 	address  string
 	limit    int
@@ -16,6 +19,8 @@ type TCPOutput struct {
 	bufStats *GorStat
 }
 
+// NewTCPOutput constructor for TCPOutput
+// Initialize 10 workers which hold keep-alive connection
 func NewTCPOutput(address string) io.Writer {
 	o := new(TCPOutput)
 

plugins.go

@@ -6,23 +6,25 @@ import (
 	"strings"
 )
 
+// InOutPlugins struct for holding references to plugins
 type InOutPlugins struct {
 	Inputs  []io.Reader
 	Outputs []io.Writer
 }
 
-type ReaderOrWriter interface{}
-
+// Plugins holds all the plugin objects
 var Plugins *InOutPlugins = new(InOutPlugins)
 
+// extractLimitOptions detects if plugin get called with limiter support
+// Returns address and limit
 func extractLimitOptions(options string) (string, string) {
 	split := strings.Split(options, "|")
 
 	if len(split) > 1 {
 		return split[0], split[1]
-	} else {
-		return split[0], ""
 	}
+
+	return split[0], ""
 }
 
 // Automatically detects type of plugin and initialize it
@@ -45,23 +47,24 @@ func registerPlugin(constructor interface{}, options ...interface{}) {
 
 	// Calling our constructor with list of given options
 	plugin := vc.Call(vo)[0].Interface()
-	plugin_wrapper := plugin
+	pluginWrapper := plugin
 
 	if limit != "" {
-		plugin_wrapper = NewLimiter(plugin, limit)
+		pluginWrapper = NewLimiter(plugin, limit)
 	} else {
-		plugin_wrapper = plugin
+		pluginWrapper = plugin
 	}
 
 	if _, ok := plugin.(io.Reader); ok {
-		Plugins.Inputs = append(Plugins.Inputs, plugin_wrapper.(io.Reader))
+		Plugins.Inputs = append(Plugins.Inputs, pluginWrapper.(io.Reader))
 	}
 
 	if _, ok := plugin.(io.Writer); ok {
-		Plugins.Outputs = append(Plugins.Outputs, plugin_wrapper.(io.Writer))
+		Plugins.Outputs = append(Plugins.Outputs, pluginWrapper.(io.Writer))
 	}
 }
 
+// InitPlugins specify and initialize all available plugins
 func InitPlugins() {
 	for _, options := range Settings.inputDummy {
 		registerPlugin(NewDummyInput, options)

proto/proto.go

@@ -1,28 +1,50 @@
-// Low-level interaction with HTTP request payload
+/*
+Package proto provides byte-level interaction with HTTP request payload.
+
+Example of HTTP payload for future references, new line symbols escaped:
+
+	POST /upload HTTP/1.1\r\n
+	User-Agent: Gor\r\n
+	Content-Length: 11\r\n
+	\r\n
+	Hello world
+
+	GET /index.html HTTP/1.1\r\n
+	User-Agent: Gor\r\n
+	\r\n
+	\r\n
+*/
 package proto
 
 import (
 	"bytes"
 	"github.com/buger/gor/byteutils"
-	_ "log"
 )
 
+// In HTTP newline defined by 2 bytes (for both windows and *nix support)
 var CLRF = []byte("\r\n")
-var EMPTY_LINE = []byte("\r\n\r\n")
-var HEADER_DELIM = []byte(": ")
 
-// Headers should end with empty line
+// New line acts as separator: end of Headers or Body (in some cases)
+var EmptyLine = []byte("\r\n\r\n")
+
+// Separator for Header line. Header looks like: `HeaderName: value`
+var HeaderDelim = []byte(": ")
+
+// MIMEHeadersEndPos finds end of the Headers section, which should end with empty line.
 func MIMEHeadersEndPos(payload []byte) int {
-	return bytes.Index(payload, EMPTY_LINE)
+	return bytes.Index(payload, EmptyLine)
 }
 
+// MIMEHeadersStartPos finds start of Headers section
+// It just finds position of second line (first contains location and method).
 func MIMEHeadersStartPos(payload []byte) int {
 	return bytes.Index(payload, CLRF) + 2 // Find first line end
 }
 
-// Find header value or return error
-// Do not support multi-line headers
-func Header(payload []byte, name []byte) (value []byte, headerStart, valueStart, headerEnd int) {
+// header return value and positions of header/value start/end.
+// If not found, value will be blank, and headerStart will be -1
+// Do not support multi-line headers.
+func header(payload []byte, name []byte) (value []byte, headerStart, valueStart, headerEnd int) {
 	headerStart = bytes.Index(payload, name)
 
 	if headerStart == -1 {
@@ -31,7 +53,7 @@ func Header(payload []byte, name []byte) (value []byte, headerStart, valueStart,
 
 	valueStart = headerStart + len(name) + 1 // Skip ":" after header name
 	if payload[valueStart] == ' ' {          // Ignore empty space after ':'
-		valueStart += 1
+		valueStart++
 	}
 	headerEnd = valueStart + bytes.IndexByte(payload[valueStart:], '\r')
 	value = payload[valueStart:headerEnd]
@@ -39,27 +61,32 @@ func Header(payload []byte, name []byte) (value []byte, headerStart, valueStart,
 	return
 }
 
-func GetHeader(payload []byte, name string) []byte {
-	val, _, _, _ := Header(payload, []byte(name))
+// Header returns header value, if header not found, value will be blank
+func Header(payload, name []byte) []byte {
+	val, _, _, _ := header(payload, name)
 
 	return val
 }
 
+// SetHeader sets header value. If header not found it creates new one.
+// Returns modified request payload
 func SetHeader(payload, name, value []byte) []byte {
-	_, hs, vs, he := Header(payload, name)
+	_, hs, vs, he := header(payload, name)
 
-	// If header found
 	if hs != -1 {
+		// If header found we just repace its value
 		return byteutils.Replace(payload, vs, he, value)
-	} else {
-		return AddHeader(payload, name, value)
 	}
+
+	return AddHeader(payload, name, value)
 }
 
+// AddHeader takes http payload and appends new header to the start of headers section
+// Returns modified request payload
 func AddHeader(payload, name, value []byte) []byte {
 	header := make([]byte, len(name)+2+len(value)+2)
 	copy(header[0:], name)
-	copy(header[len(name):], HEADER_DELIM)
+	copy(header[len(name):], HeaderDelim)
 	copy(header[len(name)+2:], value)
 	copy(header[len(header)-2:], CLRF)
 
@@ -68,30 +95,31 @@ func AddHeader(payload, name, value []byte) []byte {
 	return byteutils.Insert(payload, mimeStart, header)
 }
 
+// Path takes payload and retuns request path: Split(firstLine, ' ')[1]
 func Path(payload []byte) []byte {
-	start := bytes.IndexByte(payload, ' ')
-	start += 1
-
+	start := bytes.IndexByte(payload, ' ') + 1
 	end := bytes.IndexByte(payload[start:], ' ')
 
 	return payload[start : start+end]
 }
 
+// SetPath takes payload, sets new path and returns modified payload
 func SetPath(payload, path []byte) []byte {
-	start := bytes.IndexByte(payload, ' ')
-	start += 1
-
+	start := bytes.IndexByte(payload, ' ') + 1
 	end := bytes.IndexByte(payload[start:], ' ')
 
 	return byteutils.Replace(payload, start, start+end, path)
 }
 
+// PathParam returns URL query attribute by given name, if no found: valueStart will be -1
 func PathParam(payload, name []byte) (value []byte, valueStart, valueEnd int) {
 	path := Path(payload)
 
 	if paramStart := bytes.Index(path, append(name, '=')); paramStart != -1 {
 		valueStart := paramStart + len(name) + 1
 		paramEnd := bytes.IndexByte(path[valueStart:], '&')
+
+		// Param can end with '&' (another param), or end of line
 		if paramEnd == -1 { // It is final param
 			paramEnd = len(path)
 		} else {
@@ -99,43 +127,51 @@ func PathParam(payload, name []byte) (value []byte, valueStart, valueEnd int) {
 		}
 
 		return path[valueStart:paramEnd], valueStart, paramEnd
-	} else {
-		return []byte(""), -1, -1
 	}
+
+	return []byte(""), -1, -1
 }
 
+// SetPathParam takes payload and updates path Query attribute
+// If query param not found, it will append new
+// Returns modified payload
 func SetPathParam(payload, name, value []byte) []byte {
 	path := Path(payload)
 	_, vs, ve := PathParam(payload, name)
 
-	if vs != -1 {
+	if vs != -1 { // If param found, replace its value and set new Path
 		newPath := make([]byte, len(path))
 		copy(newPath, path)
 		newPath = byteutils.Replace(newPath, vs, ve, value)
 
-		return SetPath(payload, newPath)
-	} else { // if param not found append to end of url
-		// Adding 2 because of '?' or '&' at start, and '=' in middle
-		newParam := make([]byte, len(name)+len(value)+2)
-
-		if bytes.IndexByte(path, '?') == -1 {
-			newParam[0] = '?'
-		} else {
-			newParam[0] = '&'
-		}
-
-		copy(newParam[1:], name)
-		newParam[1+len(name)] = '='
-		copy(newParam[2+len(name):], value)
-
-		newPath := make([]byte, len(path)+len(newParam))
-		copy(newPath, path)
-		copy(newPath[len(path):], newParam)
-
 		return SetPath(payload, newPath)
 	}
+
+	// if param not found append to end of url
+	// Adding 2 because of '?' or '&' at start, and '=' in middle
+	newParam := make([]byte, len(name)+len(value)+2)
+
+	if bytes.IndexByte(path, '?') == -1 {
+		newParam[0] = '?'
+	} else {
+		newParam[0] = '&'
+	}
+
+	// Copy "param=value" into buffer, after it looks like "?param=value"
+	copy(newParam[1:], name)
+	newParam[1+len(name)] = '='
+	copy(newParam[2+len(name):], value)
+
+	// Append param to the end of path
+	newPath := make([]byte, len(path)+len(newParam))
+	copy(newPath, path)
+	copy(newPath[len(path):], newParam)
+
+	return SetPath(payload, newPath)
 }
 
+// SetHost updates Host header for HTTP/1.1 or updates host in path for HTTP/1.0 or Proxy requests
+// Returns modified payload
 func SetHost(payload, url, host []byte) []byte {
 	// If this is HTTP 1.0 traffic or proxy traffic it may include host right into path variable, so instead of setting Host header we rewrite Path
 	// Fix for https://github.com/buger/gor/issues/156
@@ -149,18 +185,20 @@ func SetHost(payload, url, host []byte) []byte {
 		newPath = byteutils.Replace(newPath, 0, hostEnd, url)
 
 		return SetPath(payload, newPath)
-	} else {
-		return SetHeader(payload, []byte("Host"), host)
 	}
+
+	return SetHeader(payload, []byte("Host"), host)
 }
 
+// Method returns HTTP method
 func Method(payload []byte) []byte {
 	end := bytes.IndexByte(payload, ' ')
 
 	return payload[:end]
 }
 
-// Status in response have same position as Path in request
+// Status returns response status.
+// It happend to be in same position as request payload path
 func Status(payload []byte) []byte {
 	return Path(payload)
 }

proto/proto_test.go

@@ -11,17 +11,17 @@ func TestHeader(t *testing.T) {
 
 	payload = []byte("POST /post HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
 
-	if val, _, _, _ = Header(payload, []byte("Content-Length")); !bytes.Equal(val, []byte("7")) {
+	if val = Header(payload, []byte("Content-Length")); !bytes.Equal(val, []byte("7")) {
 		t.Error("Should find header value")
 	}
 
 	payload = []byte("POST /post HTTP/1.1\r\nContent-Length:7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
 
-	if val, _, _, _ = Header(payload, []byte("Content-Length")); !bytes.Equal(val, []byte("7")) {
+	if val = Header(payload, []byte("Content-Length")); !bytes.Equal(val, []byte("7")) {
 		t.Error("Should find header value without space after :")
 	}
 
-	if _, headerStart, _, _ = Header(payload, []byte("Not-Found")); headerStart != -1 {
+	if _, headerStart, _, _ = header(payload, []byte("Not-Found")); headerStart != -1 {
 		t.Error("Should not found header")
 	}
 }
@@ -50,19 +50,19 @@ func TestMIMEHeadersStartPos(t *testing.T) {
 }
 
 func TestSetHeader(t *testing.T) {
-	var payload, payload_after []byte
+	var payload, payloadAfter []byte
 
 	payload = []byte("POST /post HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
-	payload_after = []byte("POST /post HTTP/1.1\r\nContent-Length: 14\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	payloadAfter = []byte("POST /post HTTP/1.1\r\nContent-Length: 14\r\nHost: www.w3.org\r\n\r\na=1&b=2")
 
-	if payload = SetHeader(payload, []byte("Content-Length"), []byte("14")); !bytes.Equal(payload, payload_after) {
+	if payload = SetHeader(payload, []byte("Content-Length"), []byte("14")); !bytes.Equal(payload, payloadAfter) {
 		t.Error("Should update header if it exists", string(payload))
 	}
 
 	payload = []byte("POST /post HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
-	payload_after = []byte("POST /post HTTP/1.1\r\nUser-Agent: Gor\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	payloadAfter = []byte("POST /post HTTP/1.1\r\nUser-Agent: Gor\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
 
-	if payload = SetHeader(payload, []byte("User-Agent"), []byte("Gor")); !bytes.Equal(payload, payload_after) {
+	if payload = SetHeader(payload, []byte("User-Agent"), []byte("Gor")); !bytes.Equal(payload, payloadAfter) {
 		t.Error("Should add header if not found", string(payload))
 	}
 }
@@ -78,12 +78,12 @@ func TestPath(t *testing.T) {
 }
 
 func TestSetPath(t *testing.T) {
-	var payload, payload_after []byte
+	var payload, payloadAfter []byte
 
 	payload = []byte("POST /post HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
-	payload_after = []byte("POST /new_path HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	payloadAfter = []byte("POST /new_path HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
 
-	if payload = SetPath(payload, []byte("/new_path")); !bytes.Equal(payload, payload_after) {
+	if payload = SetPath(payload, []byte("/new_path")); !bytes.Equal(payload, payloadAfter) {
 		t.Error("Should replace path", string(payload))
 	}
 }
@@ -103,44 +103,44 @@ func TestPathParam(t *testing.T) {
 }
 
 func TestSetPathParam(t *testing.T) {
-	var payload, payload_after []byte
+	var payload, payloadAfter []byte
 
 	payload = []byte("POST /post?param=test&user_id=1 HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
-	payload_after = []byte("POST /post?param=new&user_id=1 HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	payloadAfter = []byte("POST /post?param=new&user_id=1 HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
 
-	if payload = SetPathParam(payload, []byte("param"), []byte("new")); !bytes.Equal(payload, payload_after) {
+	if payload = SetPathParam(payload, []byte("param"), []byte("new")); !bytes.Equal(payload, payloadAfter) {
 		t.Error("Should replace existing value", string(payload))
 	}
 
 	payload = []byte("POST /post?param=test&user_id=1 HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
-	payload_after = []byte("POST /post?param=test&user_id=2 HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	payloadAfter = []byte("POST /post?param=test&user_id=2 HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
 
-	if payload = SetPathParam(payload, []byte("user_id"), []byte("2")); !bytes.Equal(payload, payload_after) {
+	if payload = SetPathParam(payload, []byte("user_id"), []byte("2")); !bytes.Equal(payload, payloadAfter) {
 		t.Error("Should replace existing value", string(payload))
 	}
 
 	payload = []byte("POST /post HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
-	payload_after = []byte("POST /post?param=test HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	payloadAfter = []byte("POST /post?param=test HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
 
-	if payload = SetPathParam(payload, []byte("param"), []byte("test")); !bytes.Equal(payload, payload_after) {
+	if payload = SetPathParam(payload, []byte("param"), []byte("test")); !bytes.Equal(payload, payloadAfter) {
 		t.Error("Should set param if url have no params", string(payload))
 	}
 
 	payload = []byte("POST /post?param=test HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
-	payload_after = []byte("POST /post?param=test&user_id=1 HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	payloadAfter = []byte("POST /post?param=test&user_id=1 HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
 
-	if payload = SetPathParam(payload, []byte("user_id"), []byte("1")); !bytes.Equal(payload, payload_after) {
+	if payload = SetPathParam(payload, []byte("user_id"), []byte("1")); !bytes.Equal(payload, payloadAfter) {
 		t.Error("Should set param at the end if url params", string(payload))
 	}
 }
 
 func TestSetHostHTTP10(t *testing.T) {
-	var payload, payload_after []byte
+	var payload, payloadAfter []byte
 
 	payload = []byte("POST http://example.com/post HTTP/1.0\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
-	payload_after = []byte("POST http://new.com/post HTTP/1.0\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	payloadAfter = []byte("POST http://new.com/post HTTP/1.0\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
 
-	if payload = SetHost(payload, []byte("http://new.com"), []byte("new.com")); !bytes.Equal(payload, payload_after) {
+	if payload = SetHost(payload, []byte("http://new.com"), []byte("new.com")); !bytes.Equal(payload, payloadAfter) {
 		t.Error("Should replace host", string(payload))
 	}
 }

raw_socket_listener/listener.go

@@ -1,4 +1,16 @@
-package raw_socket
+/*
+Package rawSocket provides traffic sniffier using RAW sockets.
+
+Capture traffic from socket using RAW_SOCKET's
+http://en.wikipedia.org/wiki/Raw_socket
+
+RAW_SOCKET allow you listen for traffic on any port (e.g. sniffing) because they operate on IP level.
+
+Ports is TCP feature, same as flow control, reliable transmission and etc.
+
+This package implements own TCP layer: TCP packets is parsed using tcp_packet.go, and flow control is managed by tcp_message.go
+*/
+package rawSocket
 
 import (
 	"bytes"
@@ -8,41 +20,41 @@ import (
 	"strconv"
 )
 
-// Capture traffic from socket using RAW_SOCKET's
-// http://en.wikipedia.org/wiki/Raw_socket
-//
-// RAW_SOCKET allow you listen for traffic on any port (e.g. sniffing) because they operate on IP level.
-// Ports is TCP feature, same as flow control, reliable transmission and etc.
-// Since we can't use default TCP libraries RAWTCPLitener implements own TCP layer
-// TCP packets is parsed using tcp_packet.go, and flow control is managed by tcp_message.go
+// Listener handle traffic capture
 type Listener struct {
-	messages map[string]*TCPMessage // buffer of TCPMessages waiting to be send
+	// buffer of TCPMessages waiting to be send
+	messages map[string]*TCPMessage
 
 	// Expect: 100-continue request is send in 2 tcp messages
 	// We store ACK aliases to merge this packets together
-	ack_aliases   map[uint32]uint32
-	seq_with_data map[uint32]uint32
+	ackAliases   map[uint32]uint32
+	// To get ACK of second message we need to compute its Seq and wait for them message
+	seqWithData map[uint32]uint32
 
-	c_packets  chan *TCPPacket
-	c_messages chan *TCPMessage // Messages ready to be send to client
+	// Messages ready to be send to client
+	packetsChan  chan *TCPPacket
 
-	c_del_message chan *TCPMessage // Used for notifications about completed or expired messages
+	// Messages ready to be send to client
+	messagesChan chan *TCPMessage
+
+	// Used for notifications about completed or expired messages
+	messageDelChan chan *TCPMessage
 
 	addr string // IP to listen
 	port int    // Port to listen
 }
 
-// RAWTCPListen creates a listener to capture traffic from RAW_SOCKET
+// NewListener creates and initializes new Listener object
 func NewListener(addr string, port string) (rawListener *Listener) {
 	rawListener = &Listener{}
 
-	rawListener.c_packets = make(chan *TCPPacket, 10000)
-	rawListener.c_messages = make(chan *TCPMessage, 10000)
-	rawListener.c_del_message = make(chan *TCPMessage, 10000)
+	rawListener.packetsChan = make(chan *TCPPacket, 10000)
+	rawListener.messagesChan = make(chan *TCPMessage, 10000)
+	rawListener.messageDelChan = make(chan *TCPMessage, 10000)
 
 	rawListener.messages = make(map[string]*TCPMessage)
-	rawListener.ack_aliases = make(map[uint32]uint32)
-	rawListener.seq_with_data = make(map[uint32]uint32)
+	rawListener.ackAliases = make(map[uint32]uint32)
+	rawListener.seqWithData = make(map[uint32]uint32)
 
 	rawListener.addr = addr
 	rawListener.port, _ = strconv.Atoi(port)
@@ -57,55 +69,55 @@ func (t *Listener) listen() {
 	for {
 		select {
 		// If message ready for deletion it means that its also complete or expired by timeout
-		case message := <-t.c_del_message:
-			t.c_messages <- message
-			delete(t.ack_aliases, message.Ack)
+		case message := <-t.messageDelChan:
+			t.messagesChan <- message
+			delete(t.ackAliases, message.Ack)
 			delete(t.messages, message.ID)
 
 		// We need to use channels to process each packet to avoid data races
-		case packet := <-t.c_packets:
+		case packet := <-t.packetsChan:
 			t.processTCPPacket(packet)
 		}
 	}
 }
 func (t *Listener) readRAWSocket() {
-    conn, e := net.ListenPacket("ip4:tcp", t.addr)
+	conn, e := net.ListenPacket("ip4:tcp", t.addr)
 
-    if e != nil {
-        log.Fatal(e)
-    }
+	if e != nil {
+		log.Fatal(e)
+	}
 
-    defer conn.Close()
+	defer conn.Close()
 
-    for {
-    	buf := make([]byte, 64*1024) // 64kb
-        // Note: ReadFrom receive messages without IP header
-        n, addr, err := conn.ReadFrom(buf)
+	for {
+		buf := make([]byte, 64*1024) // 64kb
+		// Note: ReadFrom receive messages without IP header
+		n, addr, err := conn.ReadFrom(buf)
 
-        if err != nil {
-            log.Println("Error:", err)
-            continue
-        }
+		if err != nil {
+			log.Println("Error:", err)
+			continue
+		}
 
-        if n > 0 {
-            go t.parsePacket(addr, buf[:n])
-        }
-    }
+		if n > 0 {
+			go t.parsePacket(addr, buf[:n])
+		}
+	}
 }
 
 func (t *Listener) parsePacket(addr net.Addr, buf []byte) {
-    if t.isIncomingDataPacket(buf) {
-        t.c_packets <- ParseTCPPacket(addr, buf)
-    }
+	if t.isIncomingDataPacket(buf) {
+		t.packetsChan <- ParseTCPPacket(addr, buf)
+	}
 }
 
 func (t *Listener) isIncomingDataPacket(buf []byte) bool {
 	// To avoid full packet parsing every time, we manually parsing values needed for packet filtering
 	// http://en.wikipedia.org/wiki/Transmission_Control_Protocol
-	dest_port := binary.BigEndian.Uint16(buf[2:4])
+	destPort := binary.BigEndian.Uint16(buf[2:4])
 
 	// Because RAW_SOCKET can't be bound to port, we have to control it by ourself
-	if int(dest_port) == t.port {
+	if int(destPort) == t.port {
 		// Get the 'data offset' (size of the TCP header in 32-bit words)
 		dataOffset := (buf[12] & 0xF0) >> 4
 
@@ -131,29 +143,27 @@ func (t *Listener) processTCPPacket(packet *TCPPacket) {
 
 	var message *TCPMessage
 
-	parent_message_ack, parent_ok := t.seq_with_data[packet.Seq]
-	if parent_ok {
-		t.ack_aliases[packet.Ack] = parent_message_ack
-		delete(t.seq_with_data, packet.Seq)
+	if parentAck, ok := t.seqWithData[packet.Seq]; ok {
+		t.ackAliases[packet.Ack] = parentAck
+		delete(t.seqWithData, packet.Seq)
 	}
 
-	ack_alias, alias_ok := t.ack_aliases[packet.Ack]
-	if alias_ok {
-		packet.Ack = ack_alias
+	if alias, ok := t.ackAliases[packet.Ack]; ok {
+		packet.Ack = alias
 	}
 
-	m_id := packet.Addr.String() + strconv.Itoa(int(packet.SrcPort)) + strconv.Itoa(int(packet.Ack))
-	message, ok := t.messages[m_id]
+	mID := packet.Addr.String() + strconv.Itoa(int(packet.SrcPort)) + strconv.Itoa(int(packet.Ack))
+	message, ok := t.messages[mID]
 
 	if !ok {
-		// We sending c_del_message channel, so message object can communicate with Listener and notify it if message completed
-		message = NewTCPMessage(m_id, t.c_del_message, packet.Ack)
-		t.messages[m_id] = message
+		// We sending messageDelChan channel, so message object can communicate with Listener and notify it if message completed
+		message = NewTCPMessage(mID, t.messageDelChan, packet.Ack)
+		t.messages[mID] = message
 	}
 
 	if bytes.Equal(packet.Data[0:4], bPOST) {
 		if bytes.Equal(packet.Data[len(packet.Data)-24:len(packet.Data)-4], bExpect100ContinueCheck) {
-			t.seq_with_data[packet.Seq+uint32(len(packet.Data))] = packet.Ack
+			t.seqWithData[packet.Seq+uint32(len(packet.Data))] = packet.Ack
 
 			// Removing `Expect: 100-continue` header
 			packet.Data = append(packet.Data[:len(packet.Data)-24], packet.Data[len(packet.Data)-2:]...)
@@ -161,10 +171,10 @@ func (t *Listener) processTCPPacket(packet *TCPPacket) {
 	}
 
 	// Adding packet to message
-	message.c_packets <- packet
+	message.packetsChan <- packet
 }
 
 // Receive TCP messages from the listener channel
 func (t *Listener) Receive() *TCPMessage {
-	return <-t.c_messages
+	return <-t.messagesChan
 }

raw_socket_listener/tcp_message.go

@@ -1,4 +1,4 @@
-package raw_socket
+package rawSocket
 
 import (
 	"log"
@@ -6,7 +6,8 @@ import (
 	"time"
 )
 
-const MSG_EXPIRE = 2000 * time.Millisecond
+// MsgExpire specify period that message should wait before it considered as finished
+const MsgExpire = 2000 * time.Millisecond
 
 // TCPMessage ensure that all TCP packets for given request is received, and processed in right sequence
 // Its needed because all TCP message can be fragmented or re-transmitted
@@ -21,20 +22,20 @@ type TCPMessage struct {
 
 	timer *time.Timer // Used for expire check
 
-	c_packets chan *TCPPacket
+	packetsChan chan *TCPPacket
 
-	c_del_message chan *TCPMessage
+	delChan chan *TCPMessage
 }
 
 // NewTCPMessage pointer created from a Acknowledgment number and a channel of messages readuy to be deleted
-func NewTCPMessage(ID string, c_del chan *TCPMessage, Ack uint32) (msg *TCPMessage) {
+func NewTCPMessage(ID string, delChan chan *TCPMessage, Ack uint32) (msg *TCPMessage) {
 	msg = &TCPMessage{ID: ID, Ack: Ack}
 
-	msg.c_packets = make(chan *TCPPacket)
-	msg.c_del_message = c_del // used for notifying that message completed or expired
+	msg.packetsChan = make(chan *TCPPacket)
+	msg.delChan = delChan // used for notifying that message completed or expired
 
 	// Every time we receive packet we reset this timer
-	msg.timer = time.AfterFunc(MSG_EXPIRE, msg.Timeout)
+	msg.timer = time.AfterFunc(MsgExpire, msg.Timeout)
 
 	go msg.listen()
 
@@ -44,7 +45,7 @@ func NewTCPMessage(ID string, c_del chan *TCPMessage, Ack uint32) (msg *TCPMessa
 func (t *TCPMessage) listen() {
 	for {
 		select {
-		case packet, more := <-t.c_packets:
+		case packet, more := <-t.packetsChan:
 			if more {
 				t.AddPacket(packet)
 			} else {
@@ -60,21 +61,21 @@ func (t *TCPMessage) Timeout() {
 	select {
 	// In some cases Timeout can be called multiple times (do not know how yet)
 	// Ensure that we did not close channel 2 times
-	case packet, ok := <-t.c_packets:
+	case packet, ok := <-t.packetsChan:
 		if ok {
 			t.AddPacket(packet)
 		} else {
 			return
 		}
 	default:
-		close(t.c_packets)
-		t.c_del_message <- t // Notify RAWListener that message is ready to be send to replay server
+		close(t.packetsChan)
+		t.delChan <- t // Notify RAWListener that message is ready to be send to replay server
 	}
 }
 
 // Bytes sorts packets in right orders and return message content
 func (t *TCPMessage) Bytes() (output []byte) {
-	sort.Sort(BySeq(t.packets))
+	sort.Sort(sortBySeq(t.packets))
 
 	for _, v := range t.packets {
 		output = append(output, v.Data...)
@@ -102,5 +103,5 @@ func (t *TCPMessage) AddPacket(packet *TCPPacket) {
 	}
 
 	// Reset message timeout timer
-	t.timer.Reset(MSG_EXPIRE)
+	t.timer.Reset(MsgExpire)
 }

raw_socket_listener/tcp_packet.go

@@ -1,4 +1,4 @@
-package raw_socket
+package rawSocket
 
 import (
 	"encoding/binary"
@@ -9,19 +9,18 @@ import (
 
 // TCP Flags
 const (
-	TCP_FIN = 1 << iota
-	TCP_SYN
-	TCP_RST
-	TCP_PSH
-	TCP_ACK
-	TCP_URG
-	TCP_ECE
-	TCP_CWR
-	TCP_NS
+	fFIN = 1 << iota
+	fSYN
+	fRST
+	fPSH
+	fACK
+	fURG
+	fECE
+	fCWR
+	fNS
 )
 
-// Simple TCP packet parser
-//
+// TCPPacket provides tcp packet parser
 // Packet structure: http://en.wikipedia.org/wiki/Transmission_Control_Protocol
 type TCPPacket struct {
 	SrcPort    uint16
@@ -39,6 +38,7 @@ type TCPPacket struct {
 	Addr net.Addr
 }
 
+// ParseTCPPacket takes address and tcp payload and returns parsed TCPPacket
 func ParseTCPPacket(addr net.Addr, b []byte) (p *TCPPacket) {
 	p = &TCPPacket{Data: b}
 	p.ParseBasic()
@@ -59,7 +59,7 @@ func (t *TCPPacket) Parse() {
 
 // ParseBasic set of fields
 func (t *TCPPacket) ParseBasic() {
-    t.SrcPort = binary.BigEndian.Uint16(t.Data[0:2])
+	t.SrcPort = binary.BigEndian.Uint16(t.Data[0:2])
 	t.Seq = binary.BigEndian.Uint32(t.Data[4:8])
 	t.Ack = binary.BigEndian.Uint32(t.Data[8:12])
 	t.DataOffset = (t.Data[12] & 0xF0) >> 4
@@ -76,15 +76,15 @@ func (t *TCPPacket) String() string {
 		"Acknowledgment:" + strconv.Itoa(int(t.Ack)),
 		"Header len:" + strconv.Itoa(int(t.DataOffset)),
 
-		"Flag ns:" + strconv.FormatBool(t.Flags&TCP_NS != 0),
-		"Flag crw:" + strconv.FormatBool(t.Flags&TCP_CWR != 0),
-		"Flag ece:" + strconv.FormatBool(t.Flags&TCP_ECE != 0),
-		"Flag urg:" + strconv.FormatBool(t.Flags&TCP_URG != 0),
-		"Flag ack:" + strconv.FormatBool(t.Flags&TCP_ACK != 0),
-		"Flag psh:" + strconv.FormatBool(t.Flags&TCP_PSH != 0),
-		"Flag rst:" + strconv.FormatBool(t.Flags&TCP_RST != 0),
-		"Flag syn:" + strconv.FormatBool(t.Flags&TCP_SYN != 0),
-		"Flag fin:" + strconv.FormatBool(t.Flags&TCP_FIN != 0),
+		"Flag ns:" + strconv.FormatBool(t.Flags&fNS != 0),
+		"Flag crw:" + strconv.FormatBool(t.Flags&fCWR != 0),
+		"Flag ece:" + strconv.FormatBool(t.Flags&fECE != 0),
+		"Flag urg:" + strconv.FormatBool(t.Flags&fURG != 0),
+		"Flag ack:" + strconv.FormatBool(t.Flags&fACK != 0),
+		"Flag psh:" + strconv.FormatBool(t.Flags&fPSH != 0),
+		"Flag rst:" + strconv.FormatBool(t.Flags&fRST != 0),
+		"Flag syn:" + strconv.FormatBool(t.Flags&fSYN != 0),
+		"Flag fin:" + strconv.FormatBool(t.Flags&fFIN != 0),
 
 		"Window size:" + strconv.Itoa(int(t.Window)),
 		"Checksum:" + strconv.Itoa(int(t.Checksum)),
@@ -94,8 +94,8 @@ func (t *TCPPacket) String() string {
 	}, "\n")
 }
 
-type BySeq []*TCPPacket
+type sortBySeq []*TCPPacket
 
-func (a BySeq) Len() int           { return len(a) }
-func (a BySeq) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
-func (a BySeq) Less(i, j int) bool { return a[i].Seq < a[j].Seq }
+func (a sortBySeq) Len() int           { return len(a) }
+func (a sortBySeq) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
+func (a sortBySeq) Less(i, j int) bool { return a[i].Seq < a[j].Seq }

settings.go

@@ -8,21 +8,24 @@ import (
 )
 
 const (
+	// VERSION specifies Gor current version
 	VERSION = "0.9.8"
 )
 
-// Allows to specify multiple flags with same name and collects all values to array
+// MultiOption allows to specify multiple flags with same name and collects all values into array
 type MultiOption []string
 
 func (h *MultiOption) String() string {
 	return fmt.Sprint(*h)
 }
 
+// Set gets called multiple times for each flag with same name
 func (h *MultiOption) Set(value string) error {
 	*h = append(*h, value)
 	return nil
 }
 
+// AppSettings is the struct of main configuration
 type AppSettings struct {
 	verbose bool
 	debug   bool
@@ -49,7 +52,8 @@ type AppSettings struct {
 	modifierConfig   HTTPModifierConfig
 }
 
-var Settings AppSettings = AppSettings{}
+// Settings holds Gor configuration
+var Settings AppSettings
 
 func usage() {
 	fmt.Printf("Gor is a simple http traffic replication tool written in Go. Its main goal is to replay traffic from production servers to staging and dev environments.\nProject page: https://github.com/buger/gor\nAuthor: <Leonid Bugaev> leonsbox@gmail.com\nCurrent Version: %s\n\n", VERSION)
@@ -115,6 +119,7 @@ func init() {
 	flag.Var(&Settings.modifierConfig.paramHashFilters, "http-param-limiter", "Takes a fraction of requests, consistently taking or rejecting a request based on the FNV32-1A hash of a specific GET param:\n\t gor --input-raw :8080 --output-http staging.com --http-param-limiter user_id:25%")
 }
 
+// Debug gets called only if --verbose flag specified
 func Debug(args ...interface{}) {
 	if Settings.verbose {
 		fmt.Print("[DEBUG] ")

test_input.go

@@ -5,10 +5,12 @@ import (
 	"encoding/base64"
 )
 
+// TestInput used for testing purpose, it allows emitting requests on demand
 type TestInput struct {
 	data chan []byte
 }
 
+// NewTestInput constructor for TestInput
 func NewTestInput() (i *TestInput) {
 	i = new(TestInput)
 	i.data = make(chan []byte, 100)
@@ -23,18 +25,22 @@ func (i *TestInput) Read(data []byte) (int, error) {
 	return len(buf), nil
 }
 
+// EmitGET emits GET request without headers
 func (i *TestInput) EmitGET() {
 	i.data <- []byte("GET / HTTP/1.1\r\n\r\n")
 }
 
+// EmitPOST emits POST request with Content-Length
 func (i *TestInput) EmitPOST() {
 	i.data <- []byte("POST /pub/WWW/ HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
 }
 
+// EmitChunkedPOST emits POST request with `Transfer-Encoding: chunked` and chunked body
 func (i *TestInput) EmitChunkedPOST() {
 	i.data <- []byte("POST /pub/WWW/ HTTP/1.1\r\nHost: www.w3.org\r\nTransfer-Encoding: chunked\r\n\r\n4\r\nWiki\r\n5\r\npedia\r\ne\r\n in\r\n\r\nchunks.\r\n0\r\n\r\n")
 }
 
+// EmitLargePOST emits POST request with large payload (5mb)
 func (i *TestInput) EmitLargePOST() {
 	size := 5 * 1024 * 1024 // 5 MB
 	rb := make([]byte, size)
@@ -45,6 +51,7 @@ func (i *TestInput) EmitLargePOST() {
 	i.data <- []byte("POST / HTTP/1.1\nHost: www.w3.org\nContent-Length:5242880\r\n\r\n" + rs)
 }
 
+// EmitOPTIONS emits OPTIONS request, similar to GET
 func (i *TestInput) EmitOPTIONS() {
 	i.data <- []byte("OPTIONS / HTTP/1.1\nHost: www.w3.org\r\n\r\n")
 }

test_output.go

@@ -2,10 +2,12 @@ package main
 
 type writeCallback func(data []byte)
 
+// TestOutput used in testing to intercept any output into callback
 type TestOutput struct {
 	cb writeCallback
 }
 
+// NewTestOutput constructor for TestOutput, accepts callback which get called on each incoming Write
 func NewTestOutput(cb writeCallback) (i *TestOutput) {
 	i = new(TestOutput)
 	i.cb = cb