pw_package#

Stable

The package module provides a mechanism to install additional resources used by Pigweed.

Pigweed does not (with a few very specific and small exceptions) include mirrors or submodules containing external source dependencies like FreeRTOS, STM32Cube, Raspberry Pi Pico SDK, etc. This is done to ensure projects can vendor the version of their choice, and reduces the proliferation of multiple definitions of these dependencies.

While part of this module is supported for downstream use, the general answer of whether you should use this module in your project is “no”.

Warning

This module is only intended to be used by Pigweed. Please do not rely on it.

Usage#

The package module can be accessed through the pw package command. This has several subcommands.

pw package list

Lists all the packages installed followed by all the packages available.

pw package install <package-name>

Installs <package-name>. Exactly how this works is package-dependent, and packages can decide to do nothing because the package is current, do an incremental update, or delete the current version and install anew. Use --force to remove the package before installing.

pw package status <package-name>

Indicates whether <package-name> is installed.

pw package remove <package-name>

Removes <package-name>.

By default pw package operates on the directory referenced by PW_PACKAGE_ROOT.

Middleware-Only Packages#

Pigweed itself includes a number of packages that simply clone git repositories. In general, these should not be used by projects using Pigweed. Projects should use Git submodules instead of packages. To bypass this restriction and install these packages anyway, use --force on the command line or force=True in Python code.

Configuring#

Compatibility#

Python 3

Adding a New Package#

To add a new package create a class that subclasses Package from pw_package/package_manager.py.

class Package:
    """Package to be installed.

    Subclass this to implement installation of a specific package.
    """
    def __init__(self, name):
        self._name = name

    @property
    def name(self):
        return self._name

    def install(self, path: pathlib.Path) -> None:
        """Install the package at path.

        Install the package in path. Cannot assume this directory is empty—it
        may need to be deleted or updated.
        """

    def remove(self, path: pathlib.Path) -> None:
        """Remove the package from path.

        Removes the directory containing the package. For most packages this
        should be sufficient to remove the package, and subclasses should not
        need to override this package.
        """
        if os.path.exists(path):
            shutil.rmtree(path)

    def status(self, path: pathlib.Path) -> bool:
        """Returns if package is installed at path and current.

        This method will be skipped if the directory does not exist.
        """

There’s also a helper class for retrieving specific revisions of Git repositories in pw_package/git_repo.py.

Then call pw_package.package_manager.register(PackageClass) to register the class with the package manager.

Setting up a Project#

To set up the package manager for a new project create a file like below and add it to the PW_PLUGINS file (see pw_cli for details). This file is based off of pw_package/pigweed_packages.py.

from pw_package import package_manager
# These modules register themselves so must be imported despite appearing
# unused.
from pw_package.packages import nanopb

def main(argv=None) -> int:
    return package_manager.run(**vars(package_manager.parse_args(argv)))

Options#

Options for code formatting can be specified in the pigweed.json file (see also SEED-0101). This is currently limited to one option.

  • allow_middleware_only_packages: Allow middleware-only packages to be installed. See Middleware-Only Packages for more.

{
  "pw": {
    "pw_package": {
      "allow_middleware_only_packages": true
    }
  }
}
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