mercurial/sparse.py

sparse: move config file writing into core

The code was refactored during the move to be more procedural
instead of using string formatting. This has the benefit of not
writing empty sections, which changed tests.

# sparse.py - functionality for sparse checkouts
#
# Copyright 2014 Facebook, Inc.
#
# 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 .node import nullid
from . import (
    error,
)

# Whether sparse features are enabled. This variable is intended to be
# temporary to facilitate porting sparse to core. It should eventually be
# a per-repo option, possibly a repo requirement.
enabled = False

def parseconfig(ui, raw):
    """Parse sparse config file content.

    Returns a tuple of includes, excludes, and profiles.
    """
    includes = set()
    excludes = set()
    current = includes
    profiles = []
    for line in raw.split('\n'):
        line = line.strip()
        if not line or line.startswith('#'):
            # empty or comment line, skip
            continue
        elif line.startswith('%include '):
            line = line[9:].strip()
            if line:
                profiles.append(line)
        elif line == '[include]':
            if current != includes:
                # TODO pass filename into this API so we can report it.
                raise error.Abort(_('sparse config cannot have includes ' +
                                    'after excludes'))
            continue
        elif line == '[exclude]':
            current = excludes
        elif line:
            if line.strip().startswith('/'):
                ui.warn(_('warning: sparse profile cannot use' +
                          ' paths starting with /, ignoring %s\n') % line)
                continue
            current.add(line)

    return includes, excludes, profiles

# Exists as separate function to facilitate monkeypatching.
def readprofile(repo, profile, changeid):
    """Resolve the raw content of a sparse profile file."""
    # TODO add some kind of cache here because this incurs a manifest
    # resolve and can be slow.
    return repo.filectx(profile, changeid=changeid).data()

def patternsforrev(repo, rev):
    """Obtain sparse checkout patterns for the given rev.

    Returns a tuple of iterables representing includes, excludes, and
    patterns.
    """
    # Feature isn't enabled. No-op.
    if not enabled:
        return set(), set(), []

    raw = repo.vfs.tryread('sparse')
    if not raw:
        return set(), set(), []

    if rev is None:
        raise error.Abort(_('cannot parse sparse patterns from working '
                            'directory'))

    includes, excludes, profiles = parseconfig(repo.ui, raw)
    ctx = repo[rev]

    if profiles:
        visited = set()
        while profiles:
            profile = profiles.pop()
            if profile in visited:
                continue

            visited.add(profile)

            try:
                raw = readprofile(repo, profile, rev)
            except error.ManifestLookupError:
                msg = (
                    "warning: sparse profile '%s' not found "
                    "in rev %s - ignoring it\n" % (profile, ctx))
                # experimental config: sparse.missingwarning
                if repo.ui.configbool(
                        'sparse', 'missingwarning', True):
                    repo.ui.warn(msg)
                else:
                    repo.ui.debug(msg)
                continue

            pincludes, pexcludes, subprofs = parseconfig(repo.ui, raw)
            includes.update(pincludes)
            excludes.update(pexcludes)
            for subprofile in subprofs:
                profiles.append(subprofile)

        profiles = visited

    if includes:
        includes.add('.hg*')

    return includes, excludes, profiles

def activeprofiles(repo):
    revs = [repo.changelog.rev(node) for node in
            repo.dirstate.parents() if node != nullid]

    profiles = set()
    for rev in revs:
        profiles.update(patternsforrev(repo, rev)[2])

    return profiles

def invalidatesignaturecache(repo):
    repo._sparsesignaturecache.clear()

def writeconfig(repo, includes, excludes, profiles):
    """Write the sparse config file given a sparse configuration."""
    with repo.vfs('sparse', 'wb') as fh:
        for p in sorted(profiles):
            fh.write('%%include %s\n' % p)

        if includes:
            fh.write('[include]\n')
            for i in sorted(includes):
                fh.write(i)
                fh.write('\n')

        if excludes:
            fh.write('[exclude]\n')
            for e in sorted(excludes):
                fh.write(e)
                fh.write('\n')

    invalidatesignaturecache(repo)