mercurial/similar.py
author Denis Laxalde <denis.laxalde@logilab.fr>
Tue, 17 Oct 2017 21:15:31 +0200
changeset 34857 84c6b9384d6a
parent 32202 ded48ad55146
child 38348 cd196be26cb7
permissions -rw-r--r--
log: add -L/--line-range option to follow file history by line range We add an experimental -L/--line-range option to 'hg log' taking file patterns along with a line range using the (new) FILE,FROMLINE-TOLINE syntax where FILE may be a pattern (matching exactly one file). The resulting history is similar to what the "followlines" revset except that, if --patch is specified, only diff hunks within specified line range are shown. Basically, this brings the CLI on par with what currently only exists in hgweb through line selection in "file" and "annotate" views resulting in a file log with filtered patch to only display followed line range. The option may be specified multiple times and can be combined with --rev and regular file patterns to further restrict revisions. Usage of this option requires --follow; revisions are shown in descending order and renames are followed. Only the --graph option is currently not supported. The UI is the result of a consensus from review feedback at: https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-October/106749.html The implementation spreads between commands.log() and cmdutil module. In commands.log(), the main loop may now use a "hunksfilter" factory (similar to "filematcher") that, for a given "rev", produces a filtering function for diff hunks for a given file context object. The logic to build revisions from -L/--line-range options lives in cmdutil.getloglinerangerevs() which produces "revs", "filematcher" and "hunksfilter" information. Revisions obtained by following files' line range are filtered if they do not match the revset specified by --rev option. If regular FILE arguments are passed along with -L options, both filematchers are combined into a new matcher. .. feature:: Add an experimental -L/--line-range FILE,FROMLINE-TOLINE option to 'hg log' command to follow the history of files by line range. In combination with -p/--patch option, only diff hunks within specified line range will be displayed. Feedback, especially on UX aspects, is welcome.

# similar.py - mechanisms for finding similar files
#
# Copyright 2005-2007 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

from .i18n import _
from . import (
    mdiff,
)

def _findexactmatches(repo, added, removed):
    '''find renamed files that have no changes

    Takes a list of new filectxs and a list of removed filectxs, and yields
    (before, after) tuples of exact matches.
    '''
    numfiles = len(added) + len(removed)

    # Build table of removed files: {hash(fctx.data()): [fctx, ...]}.
    # We use hash() to discard fctx.data() from memory.
    hashes = {}
    for i, fctx in enumerate(removed):
        repo.ui.progress(_('searching for exact renames'), i, total=numfiles,
                         unit=_('files'))
        h = hash(fctx.data())
        if h not in hashes:
            hashes[h] = [fctx]
        else:
            hashes[h].append(fctx)

    # For each added file, see if it corresponds to a removed file.
    for i, fctx in enumerate(added):
        repo.ui.progress(_('searching for exact renames'), i + len(removed),
                total=numfiles, unit=_('files'))
        adata = fctx.data()
        h = hash(adata)
        for rfctx in hashes.get(h, []):
            # compare between actual file contents for exact identity
            if adata == rfctx.data():
                yield (rfctx, fctx)
                break

    # Done
    repo.ui.progress(_('searching for exact renames'), None)

def _ctxdata(fctx):
    # lazily load text
    orig = fctx.data()
    return orig, mdiff.splitnewlines(orig)

def _score(fctx, otherdata):
    orig, lines = otherdata
    text = fctx.data()
    # mdiff.blocks() returns blocks of matching lines
    # count the number of bytes in each
    equal = 0
    matches = mdiff.blocks(text, orig)
    for x1, x2, y1, y2 in matches:
        for line in lines[y1:y2]:
            equal += len(line)

    lengths = len(text) + len(orig)
    return equal * 2.0 / lengths

def score(fctx1, fctx2):
    return _score(fctx1, _ctxdata(fctx2))

def _findsimilarmatches(repo, added, removed, threshold):
    '''find potentially renamed files based on similar file content

    Takes a list of new filectxs and a list of removed filectxs, and yields
    (before, after, score) tuples of partial matches.
    '''
    copies = {}
    for i, r in enumerate(removed):
        repo.ui.progress(_('searching for similar files'), i,
                         total=len(removed), unit=_('files'))

        data = None
        for a in added:
            bestscore = copies.get(a, (None, threshold))[1]
            if data is None:
                data = _ctxdata(r)
            myscore = _score(a, data)
            if myscore > bestscore:
                copies[a] = (r, myscore)
    repo.ui.progress(_('searching'), None)

    for dest, v in copies.iteritems():
        source, bscore = v
        yield source, dest, bscore

def _dropempty(fctxs):
    return [x for x in fctxs if x.size() > 0]

def findrenames(repo, added, removed, threshold):
    '''find renamed files -- yields (before, after, score) tuples'''
    wctx = repo[None]
    pctx = wctx.p1()

    # Zero length files will be frequently unrelated to each other, and
    # tracking the deletion/addition of such a file will probably cause more
    # harm than good. We strip them out here to avoid matching them later on.
    addedfiles = _dropempty(wctx[fp] for fp in sorted(added))
    removedfiles = _dropempty(pctx[fp] for fp in sorted(removed) if fp in pctx)

    # Find exact matches.
    matchedfiles = set()
    for (a, b) in _findexactmatches(repo, addedfiles, removedfiles):
        matchedfiles.add(b)
        yield (a.path(), b.path(), 1.0)

    # If the user requested similar files to be matched, search for them also.
    if threshold < 1.0:
        addedfiles = [x for x in addedfiles if x not in matchedfiles]
        for (a, b, score) in _findsimilarmatches(repo, addedfiles,
                                                 removedfiles, threshold):
            yield (a.path(), b.path(), score)