MessagePack encoding for Golang

A performance-optimized fork of vmihailenco/msgpack/v5, maintained by Basekick Labs. Built for Arc, a high-performance time-series database. The upstream module path is preserved for drop-in compatibility.

What's New in v6

Decode — ~21% faster, ~50% less memory:

• Zero-allocation byte-slice reader for Unmarshal()
• *interface{} fast path bypasses reflect for the most common decode pattern

Encode — ~12% faster, ~43% fewer allocations:

• Pooled byte buffer in Marshal() eliminates per-call bytes.Buffer
• Native WriteByte on the Marshal path removes per-byte heap allocations
• Type-switch fast paths for map[string]interface{} and []interface{}

Security:

• OOM protection: slice and map allocations from untrusted input are capped at 1M elements

See CHANGELOG.md for full details.

Resources

• Discord
• Reference
• Examples

Features

• Primitives, arrays, maps, structs, time.Time and interface{}.
• Appengine *datastore.Key and datastore.Cursor.
• CustomEncoder/CustomDecoder interfaces for custom encoding.
• Extensions to encode type information.
• Renaming fields via msgpack:"my_field_name" and alias via msgpack:"alias:another_name".
• Omitting individual empty fields via msgpack:",omitempty" tag or all empty fields in a struct.
• Map keys sorting.
• Encoding/decoding all structs as arrays or individual structs.
• Encoder.SetCustomStructTag with Decoder.SetCustomStructTag can turn msgpack into drop-in replacement for any tag.
• Simple but very fast and efficient queries.

Installation

msgpack supports 2 last Go versions and requires support for Go modules. So make sure to initialize a Go module:

go mod init github.com/my/repo

And then install msgpack (the module path is unchanged from upstream for drop-in compatibility):

go get github.com/vmihailenco/msgpack/v5

Quickstart

import "github.com/vmihailenco/msgpack/v5"

func ExampleMarshal() {
    type Item struct {
        Foo string
    }

    b, err := msgpack.Marshal(&Item{Foo: "bar"})
    if err != nil {
        panic(err)
    }

    var item Item
    err = msgpack.Unmarshal(b, &item)
    if err != nil {
        panic(err)
    }
    fmt.Println(item.Foo)
    // Output: bar
}

Contributors

Thanks to all the people who already contributed!