• Duy Nguyen's avatar
    refs: new ref types to make per-worktree refs visible to all worktrees · 3a3b9d8c
    Duy Nguyen authored
    One of the problems with multiple worktree is accessing per-worktree
    refs of one worktree from another worktree. This was sort of solved by
    multiple ref store, where the code can open the ref store of another
    worktree and has access to the ref space of that worktree.
    
    The problem with this is reporting. "HEAD" in another ref space is
    also called "HEAD" like in the current ref space. In order to
    differentiate them, all the code must somehow carry the ref store
    around and print something like "HEAD from this ref store".
    
    But that is not feasible (or possible with a _lot_ of work). With the
    current design, we pass a reference around as a string (so called
    "refname"). Extending this design to pass a string _and_ a ref store
    is a nightmare, especially when handling extended SHA-1 syntax.
    
    So we do it another way. Instead of entering a separate ref space, we
    make refs from other worktrees available in the current ref space. So
    "HEAD" is always HEAD of the current worktree, but then we can have
    "worktrees/blah/HEAD" to denote HEAD from a worktree named
    "blah". This syntax coincidentally matches the underlying directory
    structure which makes implementation a bit easier.
    
    The main worktree has to be treated specially because well... it's
    special from the beginning. So HEAD from the main worktree is
    acccessible via the name "main-worktree/HEAD" instead of
    "worktrees/main/HEAD" because "main" could be just another secondary
    worktree.
    
    This patch also makes it possible to specify refs from one worktree in
    another one, e.g.
    
        git log worktrees/foo/HEAD
    Signed-off-by: Duy Nguyen's avatarNguyễn Thái Ngọc Duy <pclouds@gmail.com>
    Signed-off-by: 's avatarJunio C Hamano <gitster@pobox.com>
    3a3b9d8c
worktree.c 12.2 KB