如何将DVCS集成到python应用程序中

Question

Hi I have a simple pyQt text editor,

Essentially I want to add mercurial support

I have seen in various other editors the ability to support a number of DVCS (Mercurial, GIT,Bazaar, etc), and they give the user the ability to perform functions like commit,update, etc

I really want to know what/how I can integrate mercurial in my pyQt text editor, so that it behaves more or less like other fancy Editors.

Any good tutorials/guides on how to get this done

Answer 1

There are no tutorials around this, generally however there are three approaches:

Command line interface

Mercurials command line interface is considered stable. That means that you can expect Mercurial without extensions to not change the output of a command. Using "-T json" for most commands will also result in an easily parsable Json output. This approach is robust and fairly easy to implement as you only have to call out to Mercurial and parse the json back. Most standard commands like commit , log , etc should be implementable using this

hglib

Mercurial is offering hglib. A library that is available in C and Python which allows you to interface with Mercurial via a local protocol. Mercurial will be started in server mode and you use the library to interact. This approach is also very stable, offers a better abstraction, but relies on the command server being available and implies potential API changes in the library. Note that you also have to take the license of the library into account as you are linking against them.

Embedding Mercurial

Python processes can embedd Mercurial directly by important the right modules. However the Mercurial API is internally not stable and subject to continuous change. This option offers you the most flexibility as you have access to everything, including low-level parsing of datastructures, exposing of hidden functionality such as obsolence markers. The drawbacks are: 1. you have to know what to do otherwise you might corrupt the repository 2. the api changes all the time 3. you are subject to the GPL license.