mercurial/similar.py
author Gregory Szorc <gregory.szorc@gmail.com>
Thu, 06 May 2021 16:11:13 -0700
changeset 47221 73f1a10320d1
parent 46819 d4ba4d51f85f
child 48966 6000f5b25c9b
permissions -rw-r--r--
packaging: use PyOxidizer for producing WiX MSI installer We recently taught our in-tree PyOxidizer configuration file to produce MSI installers with WiX using PyOxidizer's built-in support for doing so. This commit changes our WiX + PyOxidizer installer generation code to use this functionality. After this change, all the Python packaging code is doing is the following: * Building HTML documentation * Making gettext available to the build process. * Munging CLI arguments to variables for the `pyoxidizer` execution. * Invoking `pyoxidizer build`. * Copying the produced `.msi` to the `dist/` directory. Applying this stack on stable and rebuilding the 5.8 MSI installer produced the following differences from the official 5.8 installer: * .exe and .pyd files aren't byte identical (this is expected). * Various .dist-info/ directories have different names due to older versions of PyOxidizer being buggy and not properly normalizing package names. (The new behavior is correct.) * Various *.dist-info/RECORD files are different due to content divergence of files (this is expected). * The python38.dll differs due to newer PyOxidizer shipping a newer version of Python 3.8. * We now ship python3.dll because PyOxidizer now includes this file by default. * The vcruntime140.dll differs because newer PyOxidizer installs a newer version. We also now ship a vcruntime140_1.dll because newer versions of the redistributable ship 2 files now. The WiX GUIDs and IDs of installed files have likely changed as a result of PyOxidizer's different mechanism for generating those identifiers. This means that an upgrade install of the MSI will replace files instead of doing an incremental update. This is likely harmless and we've incurred this kind of breakage before. As far as I can tell, the new PyOxidizer-built MSI is functionally equivalent to the old method. Once we drop support for Python 2.7 MSI installers, we can delete the WiX code from the repository. This commit temporarily drops support for extra `.wxs` files. We raise an exception instead of silently not using them, which I think is appropriate. We should be able to add support back in by injecting state into pyoxidizer.bzl via `--var`. I just didn't want to expend cognitive load to think about the solution as part of this series. Differential Revision: https://phab.mercurial-scm.org/D10688

# similar.py - mechanisms for finding similar files
#
# Copyright 2005-2007 Olivia Mackall <olivia@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,
    pycompat,
)


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.
    """
    # Build table of removed files: {hash(fctx.data()): [fctx, ...]}.
    # We use hash() to discard fctx.data() from memory.
    hashes = {}
    progress = repo.ui.makeprogress(
        _(b'searching for exact renames'),
        total=(len(added) + len(removed)),
        unit=_(b'files'),
    )
    for fctx in removed:
        progress.increment()
        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 fctx in added:
        progress.increment()
        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
    progress.complete()


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 = {}
    progress = repo.ui.makeprogress(
        _(b'searching for similar files'), unit=_(b'files'), total=len(removed)
    )
    for r in removed:
        progress.increment()
        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)
    progress.complete()

    for dest, v in pycompat.iteritems(copies):
        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)