https://github.com/dreamacro/protobytes
https://github.com/dreamacro/protobytes
bytes golang io
Last synced: 9 months ago
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- Host: GitHub
- URL: https://github.com/dreamacro/protobytes
- Owner: Dreamacro
- License: mit
- Created: 2023-03-21T11:40:22.000Z (almost 3 years ago)
- Default Branch: main
- Last Pushed: 2025-03-22T14:29:55.000Z (10 months ago)
- Last Synced: 2025-04-21T18:21:32.986Z (9 months ago)
- Topics: bytes, golang, io
- Language: Go
- Homepage:
- Size: 40 KB
- Stars: 21
- Watchers: 2
- Forks: 34
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# Protobytes
Protobytes is a Go library inspired by Rust's crate bytes. It provides a series of methods for big-endian and little-endian number operations, as well as a helper for `io.Reader`.
## Purpose
The goal of this library is to provide an easy-to-use `bytes.Buffer`. However, it has been split into `BytesReader` and `BytesWriter`, which perform similarly to using `bytes.Buffer` directly.
When using `bytes.Buffer`, `binary.Write` has poor performance and unnecessary allocation. Instead, you can use the methods provided by protobytes.
## Usage
`BytesReader` and `BytesWriter` are similar to `bytes.Buffer`, but they are not thread-safe. `bytes.Buffer`, `binary.Write` and `[]byte` conversion is very easy and cheap.
```go
buf := make([]byte, 0, 1024)
w := BytesWriter(buf)
w.ReadFull(rand.Reader, 64)
w.PutUint8(0x01)
w.PutUint16be(0x0203)
r := BytesReader(w.Bytes())
randomBytes, r := r.SplitAt(64) // split to two BytesReader
r.ReadUint8() // auto step forward
r.ReadUint16be()
```
example for parse proxy protocol v2 using `BytesReader`:
```go
hexStr := "0d0a0d0a000d0a515549540a20120c000c22384eac10000104d21f90"
buf, _ := hex.DecodeString(hexStr)
r := BytesReader(buf)
if r.Len() < 16 {
panic("short buffer")
}
sign, r := r.SplitAt(12)
if !bytes.Equal(signature, sign) {
panic("invalid signature")
}
header := &Header{}
switch command := r.ReadUint8(); command {
case LOCAL, PROXY:
header.Command = command
default:
panic(fmt.Errorf("invalid command %x", command))
}
switch protocol := r.ReadUint8(); protocol {
case UNSPEC, TCPOverIPv4, UDPOverIPv4, TCPOverIPv6, UDPOverIPv6, UNIXStream, UNIXDatagram:
header.TransportProtocol = protocol
default:
panic(fmt.Errorf("invalid protocol %x", protocol))
}
length := r.ReadUint16le()
switch length {
case lengthIPv4, lengthIPv6, lengthUnix:
default:
panic(fmt.Errorf("invalid length %x", length))
}
if r.Len() < int(length) {
panic("short buffer")
}
switch length {
case lengthIPv4:
srcAddr := r.ReadIPv4()
dstAddr := r.ReadIPv4()
srcPort := r.ReadUint16be()
dstPort := r.ReadUint16be()
header.SourceAddr = netip.AddrPortFrom(srcAddr, srcPort)
header.DestinationAddr = netip.AddrPortFrom(dstAddr, dstPort)
case lengthIPv6:
srcAddr := r.ReadIPv6()
dstAddr := r.ReadIPv6()
srcPort := r.ReadUint16be()
dstPort := r.ReadUint16be()
header.SourceAddr = netip.AddrPortFrom(srcAddr, srcPort)
header.DestinationAddr = netip.AddrPortFrom(dstAddr, dstPort)
default:
panic(fmt.Errorf("unsupported protocol %x", length))
}
fmt.Printf("%+v\n", header)
```