docs/guide/go/basic-serialization.md

title: Basic Serialization sidebar_position: 20 id: basic_serialization license: | Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the “License”); you may not use this file except in compliance with the License. You may obtain a copy of the License at

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This guide covers the core serialization APIs in Fory Go.

Creating a Fory Instance

Create a Fory instance and register your types before serialization:

import "github.com/apache/fory/go/fory"

f := fory.New()

// Register struct with a type ID
f.RegisterStruct(User{}, 1)
f.RegisterStruct(Order{}, 2)

// Or register with a name (more flexible, less prone to ID conflicts, but higher serialization cost)
f.RegisterNamedStruct(User{}, "example.User")

// Register enum types
f.RegisterEnum(Color(0), 3)

Important: The Fory instance should be reused across serialization calls. Creating a new instance involves allocating internal buffers, type caches, and resolvers, which is expensive. The default Fory instance is not thread-safe; for concurrent usage, use the thread-safe wrapper (see Thread Safety).

See Type Registration for more details.

Core API

Serialize and Deserialize

The primary API for serialization:

// Serialize any value
data, err := f.Serialize(value)
if err != nil {
    // Handle error
}

// Deserialize into target
var result MyType
err = f.Deserialize(data, &result)
if err != nil {
    // Handle error
}

Marshal and Unmarshal

Aliases for Serialize and Deserialize (familiar to Go developers):

data, err := f.Marshal(value)
err = f.Unmarshal(data, &result)

Serializing Primitives

// Integers
data, _ := f.Serialize(int64(42))
var i int64
f.Deserialize(data, &i)  // i = 42

// Floats
data, _ = f.Serialize(float64(3.14))
var fl float64
f.Deserialize(data, &fl)  // fl = 3.14

// Strings
data, _ = f.Serialize("hello")
var s string
f.Deserialize(data, &s)  // s = "hello"

// Booleans
data, _ = f.Serialize(true)
var b bool
f.Deserialize(data, &b)  // b = true

Serializing Collections

Slices

// String slice
strs := []string{"a", "b", "c"}
data, _ := f.Serialize(strs)

var result []string
f.Deserialize(data, &result)
// result = ["a", "b", "c"]

// Integer slice
nums := []int64{1, 2, 3}
data, _ = f.Serialize(nums)

var intResult []int64
f.Deserialize(data, &intResult)
// intResult = [1, 2, 3]

Maps

// String to string map
m := map[string]string{"key": "value"}
data, _ := f.Serialize(m)

var result map[string]string
f.Deserialize(data, &result)
// result = {"key": "value"}

// String to int map
m2 := map[string]int64{"count": 42}
data, _ = f.Serialize(m2)

var result2 map[string]int64
f.Deserialize(data, &result2)
// result2 = {"count": 42}

Serializing Structs

Basic Struct Serialization

Only exported fields (starting with uppercase) are serialized:

type User struct {
    ID       int64   // Serialized
    Name     string  // Serialized
    password string  // NOT serialized (unexported)
}

f.RegisterStruct(User{}, 1)

user := &User{ID: 1, Name: "Alice", password: "secret"}
data, _ := f.Serialize(user)

var result User
f.Deserialize(data, &result)
// result.ID = 1, result.Name = "Alice", result.password = ""

Nested Structs

type Address struct {
    City    string
    Country string
}

type Person struct {
    Name    string
    Address Address
}

f.RegisterStruct(Address{}, 1)
f.RegisterStruct(Person{}, 2)

person := &Person{
    Name: "Alice",
    Address: Address{City: "NYC", Country: "USA"},
}

data, _ := f.Serialize(person)

var result Person
f.Deserialize(data, &result)
// result.Address.City = "NYC"

Pointer Fields

type Node struct {
    Value int32
    Child *Node
}

// Use WithTrackRef for pointer fields
f := fory.New(fory.WithTrackRef(true))
f.RegisterStruct(Node{}, 1)

root := &Node{
    Value: 1,
    Child: &Node{Value: 2, Child: nil},
}

data, _ := f.Serialize(root)

var result Node
f.Deserialize(data, &result)
// result.Child.Value = 2

Streaming API

For scenarios where you want to control the buffer:

SerializeTo

Serialize to an existing buffer:

buf := fory.NewByteBuffer(nil)

// Serialize multiple values to same buffer
f.SerializeTo(buf, value1)
f.SerializeTo(buf, value2)

// Get all serialized data
data := buf.GetByteSlice(0, buf.WriterIndex())

DeserializeFrom

Deserialize from an existing buffer:

buf := fory.NewByteBuffer(data)

var result1, result2 MyType
f.DeserializeFrom(buf, &result1)
f.DeserializeFrom(buf, &result2)

Generic API (Type-Safe)

Fory Go provides generic functions for type-safe serialization:

import "github.com/apache/fory/go/fory"

type User struct {
    ID   int64
    Name string
}

// Type-safe serialization
user := &User{ID: 1, Name: "Alice"}
data, err := fory.Serialize(f, user)

// Type-safe deserialization
var result User
err = fory.Deserialize(f, data, &result)

The generic API:

Infers type at compile time
Provides better type safety
May offer performance benefits

Error Handling

Always check errors from serialization operations:

data, err := f.Serialize(value)
if err != nil {
    switch e := err.(type) {
    case fory.Error:
        fmt.Printf("Fory error: %s (kind: %d)\n", e.Error(), e.Kind())
    default:
        fmt.Printf("Unknown error: %v\n", err)
    }
    return
}

err = f.Deserialize(data, &result)
if err != nil {
    // Handle deserialization error
}

Common error kinds:

ErrKindBufferOutOfBound: Read/write beyond buffer bounds
ErrKindTypeMismatch: Type ID mismatch during deserialization
ErrKindUnknownType: Unknown type encountered
ErrKindMaxDepthExceeded: Recursion depth limit exceeded
ErrKindHashMismatch: Struct hash mismatch (schema changed)

See Troubleshooting for error resolution.

Nil Handling

Nil Pointers

var ptr *User = nil
data, _ := f.Serialize(ptr)

var result *User
f.Deserialize(data, &result)
// result = nil

Empty Collections

// Nil slice
var slice []string = nil
data, _ := f.Serialize(slice)

var result []string
f.Deserialize(data, &result)
// result = nil

// Empty slice (different from nil)
empty := []string{}
data, _ = f.Serialize(empty)

f.Deserialize(data, &result)
// result = [] (empty, not nil)

Complete Example

package main

import (
    "fmt"
    "github.com/apache/fory/go/fory"
)

type Order struct {
    ID       int64
    Customer string
    Items    []Item
    Total    float64
}

type Item struct {
    Name     string
    Quantity int32
    Price    float64
}

func main() {
    f := fory.New()
    f.RegisterStruct(Order{}, 1)
    f.RegisterStruct(Item{}, 2)

    order := &Order{
        ID:       12345,
        Customer: "Alice",
        Items: []Item{
            {Name: "Widget", Quantity: 2, Price: 9.99},
            {Name: "Gadget", Quantity: 1, Price: 24.99},
        },
        Total: 44.97,
    }

    // Serialize
    data, err := f.Serialize(order)
    if err != nil {
        panic(err)
    }
    fmt.Printf("Serialized %d bytes\n", len(data))

    // Deserialize
    var result Order
    if err := f.Deserialize(data, &result); err != nil {
        panic(err)
    }

    fmt.Printf("Order ID: %d\n", result.ID)
    fmt.Printf("Customer: %s\n", result.Customer)
    fmt.Printf("Items: %d\n", len(result.Items))
    fmt.Printf("Total: %.2f\n", result.Total)
}