Henrietta-cache

Description

A caching helper for Henrietta which fetches eggs from various sources.

Requirements

Documentation

This egg installs a small program called henrietta-cache which reads a file containing egg-to-URI mappings. These URIs are expected to resolve to a so-called "release-info" file, which provides further instructions on how to fetch actual releases of the egg.

These releases are downloaded into a caching directory, which can then be served by henrietta for use by chicken-install.

Henrietta-cache can be invoked as follows:

 henrietta-cache [-h] [-r|-chicken-release RELEASE] [-c|-cache-dir CACHEDIR] [-e|-egg-list EGGLIST] [-k|-keep KEEPNUM] [-i|-init-file INITFILE] [-n|-no-download]

The CACHEDIR points at the directory in which to place the cached files. It defaults to "cache". It will automatically create a subdirectory for each egg in the list, under which it creates one subdirectory for each egg release. This structure is used because it is expected by henrietta, and may change in the future.

The EGGLIST points to a file containing the list of eggs to fetch. It may be either a filename or an HTTP(S) URI.

The RELEASE indicates a major CHICKEN release. This will only be used when performing requests to get the correct URI. Defaults to 5.

The INITFILE is a file which will be loaded before starting the download process. This can be used to set handlers on the hooks, as documented below.

The KEEPNUM option tells henrietta-cache to prune releases so that only the KEEPNUM latest remain.

The -no-download can be used to skip downloading newer releases. This can speed up the -keep option.

For more information about the structure of release-info files and what types of entries they can contain, see the tutorial on releasing eggs and the distributed egg repositories design document.

Hooks

[parameter] (download-release-success-hook [SUCCESS-HOOK])

This is a hook you can register to run some code whenever a full release of an egg has been successfully downloaded.

SUCCESS-HOOK is a procedure of three arguments: the major CHICKEN release (an integer), the egg name and the release version (both strings).

[parameter] (download-release-error-hook [ERROR-HOOK])

This is a hook you can register to run some code whenever a full release of an egg has failed to download.

ERROR-HOOK is a procedure of four arguments: the major CHICKEN release (an integer), the egg name, the release version and the error message on the exception that was thrown when the failure happened (the latter three are all strings).

[parameter] (download-release-info-file-error-hook [ERROR-HOOK])

This is a hook you can register to run some code whenever the download of the release-info file of an egg failed.

ERROR-HOOK is a procedure of four arguments: the major CHICKEN release (an integer), the egg name, the URI-string of the release-info file's location and the error message on the exception that was thrown when the failure happend (the latter three are all strings).

Changelog

Author

Peter Bex

Repository

http://code.more-magic.net/henrietta-cache

License

 
 Copyright (c) 2011-2024, Peter Bex
 All rights reserved.
 
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 3. The name of the authors may not be used to endorse or promote products
    derived from this software without specific prior written permission.
 
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