comparison mercurial/copies.py @ 44199:7f8bdee0034e

copies: define a type to return from mergecopies()

We'll soon return two instances of many of the dicts from
`copies.mergecopies()`. That will mean that we need to return 9
different dicts, which is clearly not manageable. This patch instead
encapsulates the 4 dicts we'll duplicate in a new type. For now, we
still just return one instance of it (plus the separate `diverge`
dict).

Differential Revision: https://phab.mercurial-scm.org/D7989

44198:8ad263c3a358

    revision 4, and if user have copytrace disabled, we prints the following
    message:

    ```other changed <file> which local deleted```

    Returns five dicts: "copy", "movewithdir", "diverge", "renamedelete" and
    "dirmove".

    "copy" is a mapping from destination name -> source name,
    where source is in c1 and destination is in c2 or vice-versa.

    "movewithdir" is a mapping from source name -> destination name,
    where the file at source present in one context but not the other
    needs to be moved to destination by the merge process, because the
    other context moved the directory it is in.

    "diverge" is a mapping of source name -> list of destination names
    for divergent renames.

    "renamedelete" is a mapping of source name -> list of destination
    names for files deleted in c1 that were renamed in c2 or vice-versa.

    "dirmove" is a mapping of detected source dir -> destination dir renames.
    This is needed for handling changes to new files previously grafted into
    renamed directories.

    This function calls different copytracing algorithms based on config.
    """
    # avoid silly behavior for update from empty dir
    if not c1 or not c2 or c1 == c2:
        return {}, {}, {}, {}, {}

    narrowmatch = c1.repo().narrowmatch()

    # avoid silly behavior for parent -> working dir
    if c2.node() is None and c1.node() == repo.dirstate.p1():
        return _dirstatecopies(repo, narrowmatch), {}, {}, {}, {}

    copytracing = repo.ui.config(b'experimental', b'copytrace')
    if stringutil.parsebool(copytracing) is False:
        # stringutil.parsebool() returns None when it is unable to parse the
        # value, so we should rely on making sure copytracing is on such cases
        return {}, {}, {}, {}, {}

    if usechangesetcentricalgo(repo):
        # The heuristics don't make sense when we need changeset-centric algos
        return _fullcopytracing(repo, c1, c2, base)

                # dst not added on side 2 (handle as regular
                # "both created" case in manifestmerge otherwise)
                copy[dst] = src


def _fullcopytracing(repo, c1, c2, base):
    """ The full copytracing algorithm which finds all the new files that were
    added from merge base up to the top commit and for each file it checks if
    this file was copied from another file.

    copies1 = pathcopies(base, c1)
    copies2 = pathcopies(base, c2)

    if not (copies1 or copies2):
        return {}, {}, {}, {}, {}

    inversecopies1 = {}
    inversecopies2 = {}
    for dst, src in copies1.items():
        inversecopies1.setdefault(src, []).append(dst)

    copy1.update(copy2)
    renamedelete1.update(renamedelete2)
    movewithdir1.update(movewithdir2)
    dirmove1.update(dirmove2)

    return copy1, movewithdir1, diverge, renamedelete1, dirmove1


def _dir_renames(repo, ctx, copy, fullcopy, addedfiles):
    """Finds moved directories and files that should move with them.

                    # if there are a few related copies then we'll merge
                    # changes into all of them. This matches the behaviour
                    # of upstream copytracing
                    copies[candidate] = f

    return copies, {}, {}, {}, {}


def _related(f1, f2):
    """return True if f1 and f2 filectx have a common ancestor

44199:7f8bdee0034e

    revision 4, and if user have copytrace disabled, we prints the following
    message:

    ```other changed <file> which local deleted```

    Returns a tuple where:

    "branch_copies" an instance of branch_copies.

    "diverge" is a mapping of source name -> list of destination names
    for divergent renames.

    This function calls different copytracing algorithms based on config.
    """
    # avoid silly behavior for update from empty dir
    if not c1 or not c2 or c1 == c2:
        return branch_copies(), {}

    narrowmatch = c1.repo().narrowmatch()

    # avoid silly behavior for parent -> working dir
    if c2.node() is None and c1.node() == repo.dirstate.p1():
        return branch_copies(_dirstatecopies(repo, narrowmatch)), {}

    copytracing = repo.ui.config(b'experimental', b'copytrace')
    if stringutil.parsebool(copytracing) is False:
        # stringutil.parsebool() returns None when it is unable to parse the
        # value, so we should rely on making sure copytracing is on such cases
        return branch_copies(), {}

    if usechangesetcentricalgo(repo):
        # The heuristics don't make sense when we need changeset-centric algos
        return _fullcopytracing(repo, c1, c2, base)

                # dst not added on side 2 (handle as regular
                # "both created" case in manifestmerge otherwise)
                copy[dst] = src


class branch_copies(object):
    """Information about copies made on one side of a merge/graft.

    "copy" is a mapping from destination name -> source name,
    where source is in c1 and destination is in c2 or vice-versa.

    "movewithdir" is a mapping from source name -> destination name,
    where the file at source present in one context but not the other
    needs to be moved to destination by the merge process, because the
    other context moved the directory it is in.

    "renamedelete" is a mapping of source name -> list of destination
    names for files deleted in c1 that were renamed in c2 or vice-versa.

    "dirmove" is a mapping of detected source dir -> destination dir renames.
    This is needed for handling changes to new files previously grafted into
    renamed directories.
    """

    def __init__(
        self, copy=None, renamedelete=None, dirmove=None, movewithdir=None
    ):
        self.copy = {} if copy is None else copy
        self.renamedelete = {} if renamedelete is None else renamedelete
        self.dirmove = {} if dirmove is None else dirmove
        self.movewithdir = {} if movewithdir is None else movewithdir


def _fullcopytracing(repo, c1, c2, base):
    """ The full copytracing algorithm which finds all the new files that were
    added from merge base up to the top commit and for each file it checks if
    this file was copied from another file.

    copies1 = pathcopies(base, c1)
    copies2 = pathcopies(base, c2)

    if not (copies1 or copies2):
        return branch_copies(), {}

    inversecopies1 = {}
    inversecopies2 = {}
    for dst, src in copies1.items():
        inversecopies1.setdefault(src, []).append(dst)

    copy1.update(copy2)
    renamedelete1.update(renamedelete2)
    movewithdir1.update(movewithdir2)
    dirmove1.update(dirmove2)

    return branch_copies(copy1, renamedelete1, dirmove1, movewithdir1), diverge


def _dir_renames(repo, ctx, copy, fullcopy, addedfiles):
    """Finds moved directories and files that should move with them.

                    # if there are a few related copies then we'll merge
                    # changes into all of them. This matches the behaviour
                    # of upstream copytracing
                    copies[candidate] = f

    return branch_copies(copies), {}


def _related(f1, f2):
    """return True if f1 and f2 filectx have a common ancestor