The focus here was to **reduce allocation in TCP parser** but speed may have hopeful improved too!
pool no longer use map's key of **string** it uses **uint64**
**Benchmarks** was revamped to be more clear
if you want to compare these results copy the benchmark in tcp/bench_test.go@reduce-allocation to tcp/bench_test.go@master:
**before(master)**:
```
BenchmarkPacketParseAndSort-4 1000000 1006 ns/op 64 B/op 2 allocs/op
BenchmarkMessageParserWithoutHint-4 625 1772309 ns/op 1000 packets/op 419096 B/op 10045 allocs/op
BenchmarkMessageParserWithHint-4 74 14969926 ns/op 1000 chunks/op 1002 packets/op 450992 B/op 10126 allocs/op
```
**After(this branch)**:
```
BenchmarkPacketParseAndSort-4 1267662 941 ns/op 64 B/op 2 allocs/op
BenchmarkMessageParserWithoutHint-4 2256 523474 ns/op 1000 packets/op 243530 B/op 1037 allocs/op
BenchmarkMessageParserWithHint-4 80 13990955 ns/op 1000 chunks/op 1002 packets/op 268609 B/op 1099 allocs/op
```
### 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**
