Code:play 

package main

import (
	"fmt"

	"github.com/vmihailenco/msgpack"
)

func main() {
	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

Code:play 

package main

import (
	"bytes"
	"fmt"

	"github.com/vmihailenco/msgpack"
)

func main() {
	type Item struct {
		_msgpack struct{} `msgpack:",asArray"`
		Foo      string
		Bar      string
	}

	var buf bytes.Buffer
	enc := msgpack.NewEncoder(&buf)
	err := enc.Encode(&Item{Foo: "foo", Bar: "bar"})
	if err != nil {
		panic(err)
	}

	dec := msgpack.NewDecoder(&buf)
	v, err := dec.DecodeInterface()
	if err != nil {
		panic(err)
	}
	fmt.Println(v)
}

Output:

[foo bar]

Code:play 

package main

import (
	"fmt"

	"github.com/vmihailenco/msgpack"
)

func main() {
	in := map[string]interface{}{"foo": 1, "hello": "world"}
	b, err := msgpack.Marshal(in)
	if err != nil {
		panic(err)
	}

	var out map[string]interface{}
	err = msgpack.Unmarshal(b, &out)
	if err != nil {
		panic(err)
	}

	fmt.Println("foo =", out["foo"])
	fmt.Println("hello =", out["hello"])

}

Output:

foo = 1
hello = world

Code:play 

package main

import (
	"fmt"

	"github.com/vmihailenco/msgpack"
)

func main() {
	type Item struct {
		Foo string
		Bar string
	}

	item := &Item{
		Foo: "hello",
	}
	b, err := msgpack.Marshal(item)
	if err != nil {
		panic(err)
	}
	fmt.Printf("item: %q\n", b)

	type ItemOmitEmpty struct {
		_msgpack struct{} `msgpack:",omitempty"`
		Foo      string
		Bar      string
	}

	itemOmitEmpty := &ItemOmitEmpty{
		Foo: "hello",
	}
	b, err = msgpack.Marshal(itemOmitEmpty)
	if err != nil {
		panic(err)
	}
	fmt.Printf("item2: %q\n", b)

}

Output:

item: "\x82\xa3Foo\xa5hello\xa3Bar\xa0"
item2: "\x81\xa3Foo\xa5hello"

Code:play 

package main

import (
	"encoding/binary"
	"fmt"
	"time"

	"github.com/vmihailenco/msgpack"
)

func init() {
	msgpack.RegisterExt(0, (*EventTime)(nil))
}

// https://github.com/fluent/fluentd/wiki/Forward-Protocol-Specification-v1#eventtime-ext-format
type EventTime struct {
	time.Time
}

var _ msgpack.Marshaler = (*EventTime)(nil)
var _ msgpack.Unmarshaler = (*EventTime)(nil)

func (tm *EventTime) MarshalMsgpack() ([]byte, error) {
	b := make([]byte, 8)
	binary.BigEndian.PutUint32(b, uint32(tm.Unix()))
	binary.BigEndian.PutUint32(b[4:], uint32(tm.Nanosecond()))
	return b, nil
}

func (tm *EventTime) UnmarshalMsgpack(b []byte) error {
	if len(b) != 8 {
		return fmt.Errorf("invalid data length: got %d, wanted 8", len(b))
	}
	sec := binary.BigEndian.Uint32(b)
	usec := binary.BigEndian.Uint32(b[4:])
	tm.Time = time.Unix(int64(sec), int64(usec))
	return nil
}

func main() {
	b, err := msgpack.Marshal(&EventTime{time.Unix(123456789, 123)})
	if err != nil {
		panic(err)
	}

	var v interface{}
	err = msgpack.Unmarshal(b, &v)
	if err != nil {
		panic(err)
	}
	fmt.Println(v.(*EventTime).UTC())

	tm := new(EventTime)
	err = msgpack.Unmarshal(b, tm)
	if err != nil {
		panic(err)
	}
	fmt.Println(tm.UTC())

}

Output:

1973-11-29 21:33:09.000000123 +0000 UTC
1973-11-29 21:33:09.000000123 +0000 UTC

Code:play 

package main

import (
	"fmt"

	"github.com/vmihailenco/msgpack"
)

type customStruct struct {
	S string
	N int
}

var _ msgpack.CustomEncoder = (*customStruct)(nil)
var _ msgpack.CustomDecoder = (*customStruct)(nil)

func (s *customStruct) EncodeMsgpack(enc *msgpack.Encoder) error {
	return enc.Encode(s.S, s.N)
}

func (s *customStruct) DecodeMsgpack(dec *msgpack.Decoder) error {
	return dec.Decode(&s.S, &s.N)
}

func main() {
	b, err := msgpack.Marshal(&customStruct{S: "hello", N: 42})
	if err != nil {
		panic(err)
	}

	var v customStruct
	err = msgpack.Unmarshal(b, &v)
	if err != nil {
		panic(err)
	}
	fmt.Printf("%#v", v)
}

Output:

msgpack_test.customStruct{S:"hello", N:42}

Code:play 

package main

import (
	"bytes"
	"fmt"

	"github.com/vmihailenco/msgpack"
)

func main() {
	b, err := msgpack.Marshal([]map[string]interface{}{
		{"id": 1, "attrs": map[string]interface{}{"phone": 12345}},
		{"id": 2, "attrs": map[string]interface{}{"phone": 54321}},
	})
	if err != nil {
		panic(err)
	}

	dec := msgpack.NewDecoder(bytes.NewBuffer(b))
	values, err := dec.Query("*.attrs.phone")
	if err != nil {
		panic(err)
	}
	fmt.Println("phones are", values)

	dec.Reset(bytes.NewBuffer(b))
	values, err = dec.Query("1.attrs.phone")
	if err != nil {
		panic(err)
	}
	fmt.Println("2nd phone is", values[0])
}

Output:

phones are [12345 54321]
2nd phone is 54321

Code:play 

package main

import (
	"bytes"
	"fmt"

	"github.com/vmihailenco/msgpack"
)

func main() {
	buf := new(bytes.Buffer)

	enc := msgpack.NewEncoder(buf)
	in := map[string]string{"hello": "world"}
	err := enc.Encode(in)
	if err != nil {
		panic(err)
	}

	dec := msgpack.NewDecoder(buf)
	dec.SetDecodeMapFunc(func(d *msgpack.Decoder) (interface{}, error) {
		n, err := d.DecodeMapLen()
		if err != nil {
			return nil, err
		}

		m := make(map[string]string, n)
		for i := 0; i < n; i++ {
			mk, err := d.DecodeString()
			if err != nil {
				return nil, err
			}

			mv, err := d.DecodeString()
			if err != nil {
				return nil, err
			}

			m[mk] = mv
		}
		return m, nil
	})

	out, err := dec.DecodeInterface()
	if err != nil {
		panic(err)
	}
	fmt.Println(out)
}

Output:

map[hello:world]

Code:play 

package main

import (
	"bytes"
	"fmt"

	"github.com/vmihailenco/msgpack"
)

func main() {
	type Item struct {
		Foo string
		Bar string
	}

	var buf bytes.Buffer
	enc := msgpack.NewEncoder(&buf).StructAsArray(true)
	err := enc.Encode(&Item{Foo: "foo", Bar: "bar"})
	if err != nil {
		panic(err)
	}

	dec := msgpack.NewDecoder(&buf)
	v, err := dec.DecodeInterface()
	if err != nil {
		panic(err)
	}
	fmt.Println(v)
}

Output:

[foo bar]