Etc: Efficient Transfer Coding

Etc is a low-level binary encoding package.

It's similar to package bytes with some extra bells and whistles.

Etc in JavaScript

API demo

While being faster than encoding/json, it provides a very similar reflection-based API.

package main

import (
  "github.com/superp00t/etc"
  "github.com/superp00t/etc/yo"
)

type Packet struct {
  ID          uint64
  Location    string
  Coordinates [2]float32
}

func main() {
  pc := Packet{
    ID:       1,
    Location: "Trinity",
    Coordinates: [2]float32{
      33.677216,
      -106.476059,
    },
  }

  data, err := etc.Marshal(pc)
  if err != nil {
    panic(err)
  }

  // Hex dump of "data":
  //
  // 01                     - ID
  // 07                     - 7 byte long string
  //   54 72 69 6e 69 74 79    "Trinity"
  // 78 b5 06 42            - X coordinate float32
  // be f3 d4 c2            - Y coordinate float32
  yo.Spew(data)
  
  var out Packet

  err = etc.Unmarshal(data, &out)
  if err != nil {
    panic(err)
  }
}

Etc also includes cross-platform utilities for easy directory manipulation.

Manual API

// Allocate empty buffer
e := etc.NewBuffer()

// Allocate buffer from string
e := etc.FromString("test")

// Allocate buffer from Base64
e := etc.FromBase64("dGVzdA==")

// Allocate buffer from bytes
e := etc.FromBytes([]byte{'t', 'e', 's', 't'})

// Create buffer as an alias to a file, preserving RAM but costing speed at runtime with disk IO
// Quite useful for parsing large files
e, err := etc.FileController("/tmp/newFile")
if err != nil {
  panic(err)
} else {
  e.Write([]byte("test"))
}

// Load a string from a defined 0-4 sector in buffer, ignoring possible zero padding bytes. This is not recommended and only included to support certain protocols and formats.
e.ReadFixedString(4) // "test"

// Write 64-bit integer to Buffer (using LEB128 integer compression)
e.WriteInt(12345678)

e.ReadInt() // 12345678

e.Base64() // dGVzdM7C8QU= (url encoding)
           //   t     e     s     t     [    12345678 (LEB128) ]
e.Bytes()  // [ 0x74, 0x65, 0x73, 0x74, 0xce, 0xc2, 0xf1, 0x05 ]