view hgext/fastannotate/commands.py @ 39772:ae531f5e583c

testing: add interface unit tests for file storage

Our strategy for supporting alternate storage backends is to define
interfaces for everything then "code to the interface."

We already have interfaces for various primitives, including file
and manifest storage.

What we don't have is generic unit tests for those interfaces. Up
to this point we've been relying on high-level integration tests
(mainly in the form of existing .t tests) to test alternate storage
backends. And my experience with developing the "simple store" test
extension is that such testing is very tedious: it takes several
minutes to run all tests and when you find a failure, it is often
non-trivial to debug.

This commit starts to change that.

This commit introduces the mercurial.testing.storage module. It
contains testing code for storage. Currently, it defines some
unittest.TestCase classes for testing the file storage interfaces.
It also defines some factory functions that allow a caller to easily
spawn a custom TestCase "bound" to a specific file storage backend
implementation.

A new .py test has been added. It simply defines a callable to produce
filelog and transaction instances on demand and then "registers" the
various test classes so the filelog class can be tested with the
storage interface unit tests.

As part of writing the tests, I identified a couple of apparent
bugs in revlog.py and filelog.py! These are tracked with inline
TODO comments.

Writing the tests makes it more obvious where the storage interface
is lacking. For example, we raise either IndexError or
error.LookupError for missing revisions depending on whether we
use an integer revision or a node. Also, we raise error.RevlogError
in various places when we should be raising a storage-agnostic
error type.

The storage interfaces are currently far from perfect and there is much
work to be done to improve them. But at least with this commit we
finally have the start of unit tests that can be used to "qualify"
the behavior of a storage backend. And when implementing and debugging
new storage backends, we now have an obvious place to define new
tests and have obvious places to insert breakpoints to facilitate
debugging. This should be invaluable when implementing new storage
backends.

I added the mercurial.testing package because these interface
conformance tests are generic and need to be usable by all storage
backends. Having the code live in tests/ would make it difficult for
storage backends implemented in extensions to test their interface
conformance. First, it would require obtaining a copy of Mercurial's
storage test code in order to test. Second, it would make testing
against multiple Mercurial versions difficult, as you would need to
import N copies of the storage testing code in order to achieve test
coverage. By making the test code part of the Mercurial distribution
itself, extensions can `import mercurial.testing.*` to access and run
the test code. The test will run against whatever Mercurial version
is active.

FWIW I've always wanted to move parts of run-tests.py into the
mercurial.* package to make the testing story simpler (e.g. imagine an
`hg debugruntests` command that could invoke the test harness). While I
have no plans to do that in the near future, establishing the
mercurial.testing package does provide a natural home for that code
should someone do this in the future.

Differential Revision: https://phab.mercurial-scm.org/D4650

# Copyright 2016-present Facebook. All Rights Reserved.
#
# commands: fastannotate commands
#
# 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

import os

from mercurial.i18n import _
from mercurial import (
    commands,
    error,
    extensions,
    patch,
    pycompat,
    registrar,
    scmutil,
    util,
)

from . import (
    context as facontext,
    error as faerror,
    formatter as faformatter,
)

cmdtable = {}
command = registrar.command(cmdtable)

def _matchpaths(repo, rev, pats, opts, aopts=facontext.defaultopts):
    """generate paths matching given patterns"""
    perfhack = repo.ui.configbool('fastannotate', 'perfhack')

    # disable perfhack if:
    # a) any walkopt is used
    # b) if we treat pats as plain file names, some of them do not have
    #    corresponding linelog files
    if perfhack:
        # cwd related to reporoot
        reporoot = os.path.dirname(repo.path)
        reldir = os.path.relpath(pycompat.getcwd(), reporoot)
        if reldir == '.':
            reldir = ''
        if any(opts.get(o[1]) for o in commands.walkopts): # a)
            perfhack = False
        else: # b)
            relpats = [os.path.relpath(p, reporoot) if os.path.isabs(p) else p
                       for p in pats]
            # disable perfhack on '..' since it allows escaping from the repo
            if any(('..' in f or
                    not os.path.isfile(
                        facontext.pathhelper(repo, f, aopts).linelogpath))
                   for f in relpats):
                perfhack = False

    # perfhack: emit paths directory without checking with manifest
    # this can be incorrect if the rev dos not have file.
    if perfhack:
        for p in relpats:
            yield os.path.join(reldir, p)
    else:
        def bad(x, y):
            raise error.Abort("%s: %s" % (x, y))
        ctx = scmutil.revsingle(repo, rev)
        m = scmutil.match(ctx, pats, opts, badfn=bad)
        for p in ctx.walk(m):
            yield p

fastannotatecommandargs = {
    r'options': [
        ('r', 'rev', '.', _('annotate the specified revision'), _('REV')),
        ('u', 'user', None, _('list the author (long with -v)')),
        ('f', 'file', None, _('list the filename')),
        ('d', 'date', None, _('list the date (short with -q)')),
        ('n', 'number', None, _('list the revision number (default)')),
        ('c', 'changeset', None, _('list the changeset')),
        ('l', 'line-number', None, _('show line number at the first '
                                     'appearance')),
        ('e', 'deleted', None, _('show deleted lines (slow) (EXPERIMENTAL)')),
        ('', 'no-content', None, _('do not show file content (EXPERIMENTAL)')),
        ('', 'no-follow', None, _("don't follow copies and renames")),
        ('', 'linear', None, _('enforce linear history, ignore second parent '
                               'of merges (EXPERIMENTAL)')),
        ('', 'long-hash', None, _('show long changeset hash (EXPERIMENTAL)')),
        ('', 'rebuild', None, _('rebuild cache even if it exists '
                                '(EXPERIMENTAL)')),
    ] + commands.diffwsopts + commands.walkopts + commands.formatteropts,
    r'synopsis': _('[-r REV] [-f] [-a] [-u] [-d] [-n] [-c] [-l] FILE...'),
    r'inferrepo': True,
}

def fastannotate(ui, repo, *pats, **opts):
    """show changeset information by line for each file

    List changes in files, showing the revision id responsible for each line.

    This command is useful for discovering when a change was made and by whom.

    By default this command prints revision numbers. If you include --file,
    --user, or --date, the revision number is suppressed unless you also
    include --number. The default format can also be customized by setting
    fastannotate.defaultformat.

    Returns 0 on success.

    .. container:: verbose

        This command uses an implementation different from the vanilla annotate
        command, which may produce slightly different (while still reasonable)
        outputs for some cases.

        Unlike the vanilla anootate, fastannotate follows rename regardless of
        the existence of --file.

        For the best performance when running on a full repo, use -c, -l,
        avoid -u, -d, -n. Use --linear and --no-content to make it even faster.

        For the best performance when running on a shallow (remotefilelog)
        repo, avoid --linear, --no-follow, or any diff options. As the server
        won't be able to populate annotate cache when non-default options
        affecting results are used.
    """
    if not pats:
        raise error.Abort(_('at least one filename or pattern is required'))

    # performance hack: filtered repo can be slow. unfilter by default.
    if ui.configbool('fastannotate', 'unfilteredrepo'):
        repo = repo.unfiltered()

    opts = pycompat.byteskwargs(opts)

    rev = opts.get('rev', '.')
    rebuild = opts.get('rebuild', False)

    diffopts = patch.difffeatureopts(ui, opts, section='annotate',
                                     whitespace=True)
    aopts = facontext.annotateopts(
        diffopts=diffopts,
        followmerge=not opts.get('linear', False),
        followrename=not opts.get('no_follow', False))

    if not any(opts.get(s)
               for s in ['user', 'date', 'file', 'number', 'changeset']):
        # default 'number' for compatibility. but fastannotate is more
        # efficient with "changeset", "line-number" and "no-content".
        for name in ui.configlist('fastannotate', 'defaultformat', ['number']):
            opts[name] = True

    ui.pager('fastannotate')
    template = opts.get('template')
    if template == 'json':
        formatter = faformatter.jsonformatter(ui, repo, opts)
    else:
        formatter = faformatter.defaultformatter(ui, repo, opts)
    showdeleted = opts.get('deleted', False)
    showlines = not bool(opts.get('no_content'))
    showpath = opts.get('file', False)

    # find the head of the main (master) branch
    master = ui.config('fastannotate', 'mainbranch') or rev

    # paths will be used for prefetching and the real annotating
    paths = list(_matchpaths(repo, rev, pats, opts, aopts))

    # for client, prefetch from the server
    if util.safehasattr(repo, 'prefetchfastannotate'):
        repo.prefetchfastannotate(paths)

    for path in paths:
        result = lines = existinglines = None
        while True:
            try:
                with facontext.annotatecontext(repo, path, aopts, rebuild) as a:
                    result = a.annotate(rev, master=master, showpath=showpath,
                                        showlines=(showlines and
                                                   not showdeleted))
                    if showdeleted:
                        existinglines = set((l[0], l[1]) for l in result)
                        result = a.annotatealllines(
                            rev, showpath=showpath, showlines=showlines)
                break
            except (faerror.CannotReuseError, faerror.CorruptedFileError):
                # happens if master moves backwards, or the file was deleted
                # and readded, or renamed to an existing name, or corrupted.
                if rebuild: # give up since we have tried rebuild already
                    raise
                else: # try a second time rebuilding the cache (slow)
                    rebuild = True
                    continue

        if showlines:
            result, lines = result

        formatter.write(result, lines, existinglines=existinglines)
    formatter.end()

_newopts = set([])
_knownopts = set([opt[1].replace('-', '_') for opt in
                  (fastannotatecommandargs[r'options'] + commands.globalopts)])

def _annotatewrapper(orig, ui, repo, *pats, **opts):
    """used by wrapdefault"""
    # we need this hack until the obsstore has 0.0 seconds perf impact
    if ui.configbool('fastannotate', 'unfilteredrepo'):
        repo = repo.unfiltered()

    # treat the file as text (skip the isbinary check)
    if ui.configbool('fastannotate', 'forcetext'):
        opts[r'text'] = True

    # check if we need to do prefetch (client-side)
    rev = opts.get(r'rev')
    if util.safehasattr(repo, 'prefetchfastannotate') and rev is not None:
        paths = list(_matchpaths(repo, rev, pats, pycompat.byteskwargs(opts)))
        repo.prefetchfastannotate(paths)

    return orig(ui, repo, *pats, **opts)

def registercommand():
    """register the fastannotate command"""
    name = '^fastannotate|fastblame|fa'
    command(name, **fastannotatecommandargs)(fastannotate)

def wrapdefault():
    """wrap the default annotate command, to be aware of the protocol"""
    extensions.wrapcommand(commands.table, 'annotate', _annotatewrapper)

@command('debugbuildannotatecache',
         [('r', 'rev', '', _('build up to the specific revision'), _('REV'))
         ] + commands.walkopts,
         _('[-r REV] FILE...'))
def debugbuildannotatecache(ui, repo, *pats, **opts):
    """incrementally build fastannotate cache up to REV for specified files

    If REV is not specified, use the config 'fastannotate.mainbranch'.

    If fastannotate.client is True, download the annotate cache from the
    server. Otherwise, build the annotate cache locally.

    The annotate cache will be built using the default diff and follow
    options and lives in '.hg/fastannotate/default'.
    """
    opts = pycompat.byteskwargs(opts)
    rev = opts.get('REV') or ui.config('fastannotate', 'mainbranch')
    if not rev:
        raise error.Abort(_('you need to provide a revision'),
                          hint=_('set fastannotate.mainbranch or use --rev'))
    if ui.configbool('fastannotate', 'unfilteredrepo'):
        repo = repo.unfiltered()
    ctx = scmutil.revsingle(repo, rev)
    m = scmutil.match(ctx, pats, opts)
    paths = list(ctx.walk(m))
    if util.safehasattr(repo, 'prefetchfastannotate'):
        # client
        if opts.get('REV'):
            raise error.Abort(_('--rev cannot be used for client'))
        repo.prefetchfastannotate(paths)
    else:
        # server, or full repo
        for i, path in enumerate(paths):
            ui.progress(_('building'), i, total=len(paths))
            with facontext.annotatecontext(repo, path) as actx:
                try:
                    if actx.isuptodate(rev):
                        continue
                    actx.annotate(rev, rev)
                except (faerror.CannotReuseError, faerror.CorruptedFileError):
                    # the cache is broken (could happen with renaming so the
                    # file history gets invalidated). rebuild and try again.
                    ui.debug('fastannotate: %s: rebuilding broken cache\n'
                             % path)
                    actx.rebuild()
                    try:
                        actx.annotate(rev, rev)
                    except Exception as ex:
                        # possibly a bug, but should not stop us from building
                        # cache for other files.
                        ui.warn(_('fastannotate: %s: failed to '
                                  'build cache: %r\n') % (path, ex))
        # clear the progress bar
        ui.write()