diff options
| -rw-r--r-- | morphlib/sourceresolver.py | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/morphlib/sourceresolver.py b/morphlib/sourceresolver.py index 4e1ff8d6..8c9fd8b8 100644 --- a/morphlib/sourceresolver.py +++ b/morphlib/sourceresolver.py @@ -23,7 +23,28 @@ import morphlib class SourceResolver(object): - '''Provides a way of resolving the set of sources for a given system.''' + '''Provides a way of resolving the set of sources for a given system. + + There are two levels of caching involved in resolving the sources to build. + + The canonical source for each source is specified in the build-command + (for strata and systems) or in the stratum morphology (for chunks). It will + be either a normal URL, or a keyed URL using a repo-alias like + 'baserock:baserock/definitions'. + + The 'remote repo cache' is a Baserock Trove system. It functions as a + normal Git server, but in addition it runs a service on port 8080 called + 'morph-cache-server' which can resolve refs, list their contents and read + specific files from the repos it holds. This allows the SourceResolver to + work out how to build something without cloning the whole repo. (If a local + build of that source ends up being necessary then it will get cloned into + the local cache later on). + + The second layer of caching is the local repository cache, which mirrors + entire repositories in $cachedir/gits. If a repo is not in the remote repo + cache then it must be present in the local repo cache. + + ''' def __init__(self, local_repo_cache, remote_repo_cache, update_repos, status_cb=None): |