Squeeze

Squeeze is a python library that allows you to hook into your VCS change sets performing actions on the different file changes. Currently the only supported VCSs are git and mercurial although I have plans to add SVN and CVS in the near future.

Installation

Installation can be performed by running the setup.py file

git clone https://github.com/ryakad/squeeze
cd squeeze
python setup.py install

Once you have installed the library and are ready use squeeze with an existing repo you will need to run the squeeze command in the base directory of the repo to setup the required folders and config files. You may also want to set your VCS to ignore the .squeeze directory.

How it works

Squeeze is used to run a callback for each diff in a change set depending on the type of change. By default squeeze will keep track of the commit identifier that it stopped at and will start at that commit next time so each diff is only processed once and in sequence. If you do not want this sequential, once per diff, style you can make use of the core classes and create your own squeeze application to do what you need.

Handling change sets

The different changes that squeeze will detect are:

squeeze.FILE_ADDED    # set when a file is added
squeeze.FILE_DELETED  # set when a file is removed
squeeze.FILE_MODIFIED # set when a file is modified
squeeze.FILE_COPIED   # set when a file is copied from an existing file
squeeze.FILE_RENAMED  # set when a file is renamed

Each user function should be defined as:

def function_name(change_type, *files):
   # handle affected file(s) here

The change_type will be a constant representing the change type that the file(s) underwent. This makes it possible to have a function that handles multiple change types. Consider the following for an example of when this is useful.

def file_added(change_type, *files):
   if change_type == squeeze.FILE_ADDED:
      # Handle file addition.
      # Path to file will be stored at files[0]
      file = files[0]
   elif change_type == squeeze.FILE_COPIED:
      # Handle file copy
      # For copies and renames files[0] is the origin and files[1] is the
      # destination
      file = files[1]
   else:
      raise ArgumentError('Invalid change_type for file_added()')

   # TODO process file as being added
   pass

Once you have defined functions to be run for changes you will need to tell the application what changes you want that function called on. To do this you use the add_handler(func, type) method. You can specify multiple change types using the binary | operator.

s = squeeze.Squeeze()

function handle_rename_copy(type, *files):
   print "File {0} based off of file {1}".format(files[1], files[0])

s.add_handler(handle_rename_copy, squeeze.FILE_RENAMED | squeeze.FILE_COPIED)

To run the diff you just call the applications run() method.

Sample Application

Here is a simple git plugin that just prints all the files that were added since the last scan.

#! /usr/bin/env python

import squeeze

# Create a function that will handle file additions
def handle_add(delta, *files):
   if delta == squeeze.FILE_ADDED:
      print "ADDED " + files[0]
   elif delta == squeese.FILE_COPIED:
      print "ADDED " + files[1]

s = squeeze.Squeeze()

# Set the function to be called any time a file is added
s.add_handler(handle_add, squeeze.FILE_ADDED | squeeze.FILE_COPIED)

s.run()

For more samples you can look in the examples folder in this repo. They are a little lacking as of now but I will add some more as time goes on.

If you find any bugs or just want a new feature submit an issue on github -- or even better, a pull request.