flatbuffers

What is flatbuffers?

FlatBuffers is an efficient cross-platform serialization library for C++, C#, C, Go, Java, JavaScript, TypeScript, PHP, and Python. It allows you to create and access serialized data without parsing/unpacking it, making it ideal for performance-critical applications.

What are flatbuffers's main functionalities?

Creating a FlatBuffer

This code demonstrates how to create a FlatBuffer with a string and a vector of strings. The buffer is then finished and converted to a Uint8Array.

const flatbuffers = require('flatbuffers');
const builder = new flatbuffers.Builder(1024);

// Create a string
const str = builder.createString('Hello, FlatBuffers!');

// Create a vector of strings
const strings = builder.createVectorOfStrings(['foo', 'bar', 'baz']);

// Finish the buffer
builder.finish(strings);

// Get the buffer
const buf = builder.asUint8Array();
console.log(buf);

Reading a FlatBuffer

This code demonstrates how to read a FlatBuffer. It assumes that the buffer contains data for a 'Monster' object, and it accesses the 'name' and 'hp' fields of the object.

const flatbuffers = require('flatbuffers');
const MyGame = require('./mygame_generated'); // Generated code

// Assume buf is a Uint8Array containing the FlatBuffer data
const buf = new Uint8Array([/* FlatBuffer data */]);

// Get the root object
const bb = new flatbuffers.ByteBuffer(buf);
const root = MyGame.Example.Monster.getRootAsMonster(bb);

// Access data
console.log(root.name());
console.log(root.hp());

Other packages similar to flatbuffers

protobufjs

Protobuf.js is a pure JavaScript implementation of Protocol Buffers, a language-neutral, platform-neutral, extensible mechanism for serializing structured data. Compared to FlatBuffers, Protobuf.js requires a parsing step to access data, which can be less efficient in performance-critical applications.

msgpack

MessagePack is an efficient binary serialization format. It lets you exchange data among multiple languages like JSON but it's faster and smaller. Compared to FlatBuffers, MessagePack is simpler but may not offer the same level of performance for complex data structures.

avsc

Avro is a data serialization system that provides rich data structures and a compact, fast, binary data format. The 'avsc' package is a pure JavaScript implementation of Avro. Compared to FlatBuffers, Avro is more focused on schema evolution and data interchange, while FlatBuffers is optimized for performance.

README

FlatBuffers

FlatBuffers is a cross platform serialization library architected for maximum memory efficiency. It allows you to directly access serialized data without parsing/unpacking it first, while still having great forwards/backwards compatibility.

Quick Start

1. Build the compiler for flatbuffers (flatc)

   Use cmake to create the build files for your platform and then perform the compliation (Linux example).

   cmake -G "Unix Makefiles"
   make -j
   

2. Define your flatbuffer schema (.fbs)

   Write the schema to define the data you want to serialize. See monster.fbs for an example.

3. Generate code for your language(s)

   Use the flatc compiler to take your schema and generate language-specific code:

   ./flatc --cpp --rust monster.fbs
   

   Which generates monster_generated.h and monster_generated.rs files.

4. Serialize data

   Use the generated code, as well as the FlatBufferBuilder to construct your serialized buffer. (C++ example)

5. Transmit/store/save Buffer

   Use your serialized buffer however you want. Send it to someone, save it for later, etc...

6. Read the data

   Use the generated accessors to read the data from the serialized buffer.

   It doesn't need to be the same language/schema version, FlatBuffers ensures the data is readable across languages and schema versions. See the Rust example reading the data written by C++.

Documentation

Go to our landing page to browse our documentation.

Supported operating systems

• Windows
• macOS
• Linux
• Android
• And any others with a recent C++ compiler (C++ 11 and newer)

Supported programming languages

Code generation and runtime libraries for many popular languages.

1. C
2. C++ - snapcraft.io
3. C# - nuget.org
4. Dart - pub.dev
5. Go - go.dev
6. Java - Maven
7. JavaScript - NPM
8. Kotlin
9. Lobster
10. Lua
11. PHP
12. Python - PyPI
13. Rust - crates.io
14. Swift - swiftpackageindex
15. TypeScript - NPM
16. Nim

Versioning

FlatBuffers does not follow traditional SemVer versioning (see rationale) but rather uses a format of the date of the release.

Contribution

• FlatBuffers Issues Tracker to submit an issue.
• stackoverflow.com with flatbuffers tag for any questions regarding FlatBuffers.

To contribute to this project, see CONTRIBUTING.

Community

• Discord Server

Security

Please see our Security Policy for reporting vulnerabilities.

Licensing

Flatbuffers is licensed under the Apache License, Version 2.0. See LICENSE for the full license text.

Changelog

[24.3.25] (March 25 2024)(https://github.com/google/flatbuffers/releases/tag/v24.3.25)

• Fixed license metadata parsing (#8253)
• [C++] Allow string_view in LookUpByKey in addition to null-terminated c-style strings (#8203)