Version Control System

The project contains 3 packages:

filesystem

• contains unix commands for adding, modifying and deleting files;

utils

• contains helper classes and interfaces for creating operations, generating commit ids, creating filesystem entities;

vcs

• contains the following classes:
  • Branch:
    • contains an array of commits;
  • Commit:
    • contains a filesystem snapshot;
• the Visitor Pattern is used for the following classes:
  • Vcs:
    • contains the active filesystem snapshot, the branches and the head pointer;
    • it has the role of the visitor, visits each operation;
  • VcsOperation:
    • abstract class, extends AbstractOperation;
    • has the role of the visitable element, accepts the vcs;
• all the following classes extend the VcsOperation:
  • BranchOperation:
    • creates a new branch that has the same filesystem structure as the current commit;
  • CheckoutOperation:
    • depending on the arguments, it can either move the head pointer to another branch or to another commit;
  • CommitOperation:
    • generates a new commit;
  • InvalidVcsOperation:
    • when visited, returns the error code corresponding to an invalid vcs operation;
  • LogOperation:
    • displays the commits from the current branch;
  • RollbackOperation:
    • reverts the active snapshot to the one corresponding to the last commit and empties the staging;
  • StatusOperation
    • lists the commands from the staging.