vonwenm / go-file

Slightly convenient and powerful Golang file API

go-file

go-file essentially tries to provide a wrapper for file-like objects of different backend types. It uses URLs to identify files (be they local, in Doozer or somewhere else) and provide relatively transparent access to them.

At this point, it only supports watching files in different types of file systems, but there is support planned for implementing transparent access to readers and lateron even writers.

Watchers

So far, watchers are the only implemented common method. They can be used to watch files for changes and receive a callback with the file name and an io.ReadCloser object with the modified file contents for ease of access.

The basic important function is file.Watch(). It picks the correct handler for the URL type it's being passed and invokes it. The handler itself will do its thing in the background to ensure all modifications of the affected file are noticed and reported.

The callback itself will only see an io.ReadCloser interface to use when it's being notified of changes. This means that it doesn't require any logic relevant to the underlying file system implementation to get to the files contents.

Since the contents of the modified file may actually be irrelevant, implementations are required to ensure that just closing the file without reading it means that no nontrivial cost will be incurred; any expensive initialization should be deferred until the first call to Read().