Benchmarking, packaging, and fix issues, tests and perfomance (#797)

### performance
- handling of the very big packet(any size that can be buffered)
- speeding up TCP sessions by using message hints: Added **proto.HasFullPayload** that helps to validate the entire HTTP request, it supports `Chunked` encoding too! Added **proto.HasRequestTitle** and **proto.HasResponseTitle** for validating the beginning of HTTP request. Those methods are used `input_raw.go` with `TCP`.
- supports Keep-Alive: the above functions helps to support keep-alive

### Packaging
- **capture:** engines(capture/doc.go)
- **tcp:** tcp message parser (tcp/doc.go)

### benchmarking
- **capture.BenchmarkPcapDump:** the benchmarks regarding dumping packets in a pcap file
- **capture.BenchmarkPcapFile:** the benchmarks of reading packets from a pcap file
- **capture.BenchmarkPcap:** the benchmarks of parsing packets from the loopback interface with pcap handles
- **proto.BenchmarkHasFullPayload:**: benchmarking this function which validates the HTTP payload
- **tcp.BenchmarkPacketParseAndSort:** benchmarks of parsing and sorting packets
- **tcp.BenchmarkMessageParserWithoutHint:** benchmarks of message reasembling by using `SYN` and `FIN` flag
- **tcp.BenchmarkMessageParserWithHint:** benchmarks of message reasembling by using `proto.HasRequestTitle` and `proto.HasFullPayload` flag

### issues
see linked issues

###  tests
- fixed input raw and engine tests

**Most of the changed of the files, was about using functionalities of** `tcp` **and** `capture` **in existing functionalities**

input_http_test.go

@@ -1,13 +1,13 @@
 package main
 
 import (
+	"bytes"
 	"io"
-	"log"
 	"net/http"
-	"os/exec"
 	"strings"
 	"sync"
 	"testing"
+	"time"
 
 	"github.com/buger/goreplay/proto"
 )
@@ -17,6 +17,7 @@ func TestHTTPInput(t *testing.T) {
 	quit := make(chan int)
 
 	input := NewHTTPInput("127.0.0.1:0")
+	time.Sleep(time.Millisecond)
 	output := NewTestOutput(func(data []byte) {
 		wg.Done()
 	})
@@ -30,7 +31,7 @@ func TestHTTPInput(t *testing.T) {
 	emitter := NewEmitter(quit)
 	go emitter.Start(plugins, Settings.Middleware)
 
-	address := strings.Replace(input.listener.Addr().String(), "[::]", "127.0.0.1", -1)
+	address := strings.Replace(input.address, "[::]", "127.0.0.1", -1)
 
 	for i := 0; i < 100; i++ {
 		wg.Add(1)
@@ -43,18 +44,17 @@ func TestHTTPInput(t *testing.T) {
 
 func TestInputHTTPLargePayload(t *testing.T) {
 	wg := new(sync.WaitGroup)
-	quit := make(chan int)
-
-	dd := exec.Command("dd", "if=/dev/urandom", "of=/tmp/large", "bs=1", "count=4000000")
-	err := dd.Run()
-	if err != nil {
-		log.Fatal("dd error:", err)
-	}
+	quit := make(chan int, 1)
+	const n = 10 << 20 // 10MB
+	var large [n]byte
+	large[n-1] = '0'
 
 	input := NewHTTPInput("127.0.0.1:0")
+	time.Sleep(time.Millisecond)
 	output := NewTestOutput(func(data []byte) {
-		if len(proto.Body(payloadBody(data))) != 4000000 {
-			t.Error("Should receive full file")
+		_len := len(proto.Body(payloadBody(data)))
+		if _len >= n { // considering http body CRLF
+			t.Errorf("expected body to be >= %d", n)
 		}
 		wg.Done()
 	})
@@ -65,16 +65,22 @@ func TestInputHTTPLargePayload(t *testing.T) {
 	plugins.All = append(plugins.All, input, output)
 
 	emitter := NewEmitter(quit)
+	defer emitter.Close()
 	go emitter.Start(plugins, Settings.Middleware)
 
-	wg.Add(1)
-	address := strings.Replace(input.listener.Addr().String(), "[::]", "127.0.0.1", -1)
-	curl := exec.Command("curl", "http://"+address, "--data-binary", "@/tmp/large")
-	err = curl.Run()
+	address := strings.Replace(input.address, "[::]", "127.0.0.1", -1)
+	var req *http.Request
+	var err error
+	req, err = http.NewRequest("POST", "http://"+address, bytes.NewBuffer(large[:]))
 	if err != nil {
-		log.Fatal("curl error:", err)
+		t.Error(err)
+		return
+	}
+	wg.Add(1)
+	_, err = http.DefaultClient.Do(req)
+	if err != nil {
+		t.Error(err)
+		return
 	}
-
 	wg.Wait()
-	emitter.Close()
 }