Koffi

Overview

Koffi is a fast and easy-to-use C FFI module for Node.js, featuring:

• Low-overhead and fast performance (see benchmarks)

• Support for primitive and aggregate data types (structs and fixed-size arrays), both by reference (pointer) and by value

• Javascript functions can be used as C callbacks (since 1.2.0)

• Well-tested code base for popular OS/architecture combinations

Koffi requires a recent Node.js version with N-API version 8 support, see this page for more information.

The source code is available here: https://github.com/Koromix/rygel/ (in the src/koffi subdirectory).

New releases are frequent, look at the changelog for more information.

Table of contents

• Requirements
  • Node.js
  • Supported platforms
• Get started
  • Install Koffi
  • Simple examples
    • For Linux
    • For Windows
  • Bundling Koffi
  • Build manually
• Function calls
  • Loading libraries
  • Loading options
  • Function definitions
    • Definition syntax
    • Variadic functions
    • Calling conventions
  • Call types
    • Synchronous calls
    • Asynchronous calls
  • Function pointers
    • Call pointer directly
    • Decode pointer to function
  • Conversion of parameters
• Input parameters
  • Primitive types
    • Standard types
    • Endian-sensitive integers
  • Struct types
    • Struct definition
    • Opaque types
  • Array types
    • Fixed-size C arrays
    • Fixed-size string buffers
    • Dynamic arrays (pointers)
  • Union types
• Data pointers
  • How pointers are used
  • Pointer types
    • Struct pointers
    • Opaque pointers
    • Pointer to primitive types
    • Dynamic arrays
  • Handling void pointers
  • Disposable types
  • Unwrap pointers
• Output parameters
  • Output and input/output
    • Primitive value
    • Struct example
    • Opaque type example
    • String buffer example
  • Output buffers
    • Transient pointers
    • Stable pointers
• Union values
  • Union definition
  • Input unions
    • Passing union values to C
    • Win32 example
  • Output unions
• Exported variables
  • Variable definitions
  • Decode to JS values
  • Encode to C memory
• Javascript callbacks
  • Callback types
  • Transient and registered callbacks
    • Transient callbacks
    • Registered callbacks
  • Special considerations
    • Decoding pointer arguments
    • Asynchronous callbacks
  • Handling of exceptions
• Miscellaneous
  • Types
    • Introspection
    • Aliases
  • Settings
    • Memory usage
    • Default settings
  • Usage statistics
  • POSIX error codes
  • Reset internal state
• Bundlers and Koffi
  • Bundling
    • Native modules
    • Indirect loader
  • Packaging examples
    • Electron with electron-builder
    • Electron Forge
    • NW.js
    • Node.js and esbuild
• Benchmarks
  • Overview
  • Linux x86_64
    • rand results
    • atoi results
    • Raylib results
  • Windows x86_64
    • rand results
    • atoi results
    • Raylib results
  • Running benchmarks
• Contributing
  • Bugs and feature requests
  • Build from source
    • Windows
    • Other platforms
  • Run tests
    • On your machine
    • On virtual machines
  • Making a release
  • Code style
• Changelog
  • Version history
    • Koffi 2.9
    • Koffi 2.8
    • Koffi 2.7
    • Koffi 2.6
    • Koffi 2.5
    • Koffi 2.4
    • Koffi 2.3
    • Koffi 2.2
    • Koffi 2.1
    • Koffi 2.0
    • Koffi 1.3
    • Koffi 1.2
  • Todo list
• Migration guide
  • Koffi 1.x to 2.x
    • Callback type changes
    • Opaque type changes
    • New koffi.introspect()

License

This program is free software: you can redistribute it and/or modify it under the terms of the MIT License.

Find more information here: https://choosealicense.com/licenses/mit/