rustler_precompiled
v0.7.0

View Source RustlerPrecompiled (rustler_precompiled v0.7.0)

Download and use precompiled NIFs safely with checksums.

Rustler Precompiled is a tool for library maintainers that rely on Rustler. It helps by removing the need to have the Rust compiler installed in the user's machine.

Check the Precompilation Guide for details.

Example 

defmodule MyApp.MyNative do
  use RustlerPrecompiled,
    otp_app: :my_app,
    crate: "my_app_nif",
    base_url: "https://github.com/me/my_project/releases/download/v0.1.0",
    version: "0.1.0"
end

Options

  • :otp_app - The OTP app name that the dynamic library will be loaded from.

  • :crate - The name of Rust crate if different from the :otp_app. This is optional.

  • :base_url - A valid URL that is used as base path for the NIF file.

  • :version - The version of precompiled assets (it is part of the NIF filename).

  • :force_build - Force the build with Rustler. This is false by default, but if your :version is a pre-release (like "2.1.0-dev"), this option will always be set true. You can also configure this option by setting an application env like this:

    config :rustler_precompiled, :force_build, your_otp_app: true

    It is important to add the ":rustler" package to your dependencies in order to force the build. To do that, just add it to your mix.exs file:

    {:rustler, ">= 0.0.0", optional: true}

  • :targets - A list of targets supported by Rust for which precompiled assets are available. By default the following targets are configured:

    • aarch64-apple-darwin
    • aarch64-unknown-linux-gnu
    • aarch64-unknown-linux-musl
    • arm-unknown-linux-gnueabihf
    • riscv64gc-unknown-linux-gnu
    • x86_64-apple-darwin
    • x86_64-pc-windows-gnu
    • x86_64-pc-windows-msvc
    • x86_64-unknown-linux-gnu
    • x86_64-unknown-linux-musl

  • :nif_versions - A list of OTP NIF versions for which precompiled assets are available. A NIF version is usually compatible with two OTP minor versions, and an older NIF is usually compatible with newer OTPs. The available versions are the following:

    • 2.14 - for OTP 21 and above.
    • 2.15 - for OTP 22 and above.
    • 2.16 - for OTP 24 and above.
    • 2.17 - for OTP 26 and above.

    By default the following NIF versions are configured:

    • 2.15

    Check the compatibiliy table between Elixir and OTP in: https://hexdocs.pm/elixir/compatibility-and-deprecations.html#compatibility-between-elixir-and-erlang-otp

  • :max_retries - The maximum of retries before giving up. Defaults to 3. Retries can be disabled with 0.

  • :variants - A map with alternative versions of a given target. This is useful to support specific versions of dependencies, such as an old glibc version, or to support restrict CPU features, like AVX on x86_64.

    The order of variants matters, because the first one that returns true is going to be selected. Example:

    %{"x86_64-unknown-linux-gnu" => [old_glibc: fn _config -> has_old_glibc?() end]}

In case "force build" is used, all options except the ones use by RustlerPrecompiled are going to be passed down to Rustler. So if you need to configure the build, check the Rustler options.

Environment variables

This project reads some system environment variables. They are all optional, but they can change the behaviour of this library at compile time of your project.

They are:

  • HTTP_PROXY or http_proxy - Sets the HTTP proxy configuration.

  • HTTPS_PROXY or https_proxy - Sets the HTTPS proxy configuration.

  • MIX_XDG - If present, sets the OS as :linux for the :filename.basedir/3 when getting an user cache dir.

  • TARGET_ARCH - The CPU target architecture. This is useful for when building your Nerves project, where your host CPU is different from your target CPU.

    Note that Nerves sets this value automatically when building your project.

    Examples: arm, aarch64, x86_64, riscv64.

  • TARGET_ABI - The target ABI (e.g., gnueabihf, musl). This is set by Nerves as well.

  • TARGET_VENDOR - The target vendor (e.g., unknown, apple, pc). This is not set by Nerves. If any of the TARGET_ env vars is set, but TARGET_VENDOR is empty, then we change the target vendor to unknown that is the default value for Linux systems.

  • TARGET_OS - The target operational system. This is always linux for Nerves.

For more details about Nerves env vars, see https://hexdocs.pm/nerves/environment-variables.html

Summary

Functions

available_nif_urls(nif_module)

Returns URLs for NIFs based on its module name.

current_target_nif_urls(nif_module)

Returns the file URLs to be downloaded for current target.

target(config \\ target_config(), available_targets \\ Config.default_targets(), available_nif_versions \\ Config.available_nif_versions())

Returns the target triple for download or compile and load.

Functions

Link to this function

available_nif_urls(nif_module)

View Source

Returns URLs for NIFs based on its module name.

The module name is the one that defined the NIF and this information is stored in a metadata file.

Link to this function

current_target_nif_urls(nif_module)

View Source

Returns the file URLs to be downloaded for current target.

It is in the plural because a target may have some variants for it. It receives the NIF module.

Link to this function

target(config \\ target_config(), available_targets \\ Config.default_targets(), available_nif_versions \\ Config.available_nif_versions())

View Source

Returns the target triple for download or compile and load.

This function is translating and adding more info to the system architecture returned by Elixir/Erlang to one used by Rust.

The returned string has the following format:

"nif-NIF_VERSION-ARCHITECTURE-VENDOR-OS-ABI"

Examples 

iex> RustlerPrecompiled.target()
{:ok, "nif-2.16-x86_64-unknown-linux-gnu"}

iex> RustlerPrecompiled.target()
{:ok, "nif-2.15-aarch64-apple-darwin"}