System and method for distributed revision control

A revision control system comprising:

• a revision control module executed by one or more process of a server;
• and
• a repository configured to provide access to a plurality of stored versions of a shared document;
• wherein the revision control module is configured to:
• receive a request to store a first version in the repository;
• determine whether the first version is in the repository;
• when the first version is in the repository, increment a client reference counter associated with the first version;
• when the first version is not in the repository, add the first version to the repository and send the first version to one or more additional servers;
• and
• when the first version replaces the second version as a head version of the repository, decrement a server reference counter associated with a second version in the repository.

A non-transitory machine-readable medium comprising a plurality of machine-readable instructions which when executed by one or more processors associated with a server are adapted to cause the one or more processors to perform a method comprising:

• receiving a request to store a first version in a repository, the repository comprising a plurality of stored versions;
• determining whether the first version is in the repository;
• when the first version is in the repository, incrementing a client reference counter associated with the first version;
• when the first version is not in the repository, adding the first version to the repository and sending the first version to one or more additional servers;
• when the first version replaces the second version as a head version of the repository, decrementing a server reference counter associated with a second version in the repository;
• receiving, from another server, a third version;
• adding the third version to the repository;
• determining whether the third version replaces a fourth version as a head version of the repository;
• when the third version replaces the fourth version as the head version of the repository, incrementing a server reference counter associated with the third version and decrementing a server reference counter associated with the fourth version;
• receiving a request to retrieve a fifth version from the repository;
• determining whether the fifth version is in the repository;
• and
• when the fifth version is in the repository, retrieving the fifth version from the repository and decrementing a client reference counter associated with the fifth version.