annotate mercurial/manifest.py @ 24670:dfb86af18a35

treemanifest: optimize treemanifest._walk() to skip directories

This makes treemanifest.walk() not visit submanifests that are known not to
have any matching files. It does this by calling match.visitdir() on
submanifests as it walks.

This change also updates largefiles to be able to work with this new behavior
in treemanifests. It overrides match.visitdir(), the function that dictates
how walk() and matches() skip over directories.

The greatest speed improvements are seen with narrower scopes. For example,
this commit speeds up the following command on the Mozilla repo from 1.14s
to 1.02s:
  hg files -r . dom/apps/

Whereas with a wider scope, dom/, the speed only improves from 1.21s to 1.13s.

As with similar a similar optimization to treemanifest.matches(), this change
will bring out even bigger performance improvements once treemanifests are
loaded lazily. Once that happens, we won't just skip over looking at
submanifests, but we'll skip even loading them.

# manifest.py - manifest revision class for mercurial
#
# Copyright 2005-2007 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from i18n import _
import mdiff, parsers, error, revlog, util
import array, struct
import os

propertycache = util.propertycache

def _parsev1(data):
    # This method does a little bit of excessive-looking
    # precondition checking. This is so that the behavior of this
    # class exactly matches its C counterpart to try and help
    # prevent surprise breakage for anyone that develops against
    # the pure version.
    if data and data[-1] != '\n':
        raise ValueError('Manifest did not end in a newline.')
    prev = None
    for l in data.splitlines():
        if prev is not None and prev > l:
            raise ValueError('Manifest lines not in sorted order.')
        prev = l
        f, n = l.split('\0')
        if len(n) > 40:
            yield f, revlog.bin(n[:40]), n[40:]
        else:
            yield f, revlog.bin(n), ''

def _parsev2(data):
    metadataend = data.find('\n')
    # Just ignore metadata for now
    pos = metadataend + 1
    prevf = ''
    while pos < len(data):
        end = data.find('\n', pos + 1) # +1 to skip stem length byte
        if end == -1:
            raise ValueError('Manifest ended with incomplete file entry.')
        stemlen = ord(data[pos])
        items = data[pos + 1:end].split('\0')
        f = prevf[:stemlen] + items[0]
        if prevf > f:
            raise ValueError('Manifest entries not in sorted order.')
        fl = items[1]
        # Just ignore metadata (items[2:] for now)
        n = data[end + 1:end + 21]
        yield f, n, fl
        pos = end + 22
        prevf = f

def _parse(data):
    """Generates (path, node, flags) tuples from a manifest text"""
    if data.startswith('\0'):
        return iter(_parsev2(data))
    else:
        return iter(_parsev1(data))

def _text(it, usemanifestv2):
    """Given an iterator over (path, node, flags) tuples, returns a manifest
    text"""
    if usemanifestv2:
        return _textv2(it)
    else:
        return _textv1(it)

def _textv1(it):
    files = []
    lines = []
    _hex = revlog.hex
    for f, n, fl in it:
        files.append(f)
        # if this is changed to support newlines in filenames,
        # be sure to check the templates/ dir again (especially *-raw.tmpl)
        lines.append("%s\0%s%s\n" % (f, _hex(n), fl))

    _checkforbidden(files)
    return ''.join(lines)

def _textv2(it):
    files = []
    lines = ['\0\n']
    prevf = ''
    for f, n, fl in it:
        files.append(f)
        stem = os.path.commonprefix([prevf, f])
        stemlen = min(len(stem), 255)
        lines.append("%c%s\0%s\n%s\n" % (stemlen, f[stemlen:], fl, n))
        prevf = f
    _checkforbidden(files)
    return ''.join(lines)

class _lazymanifest(dict):
    """This is the pure implementation of lazymanifest.

    It has not been optimized *at all* and is not lazy.
    """

    def __init__(self, data):
        dict.__init__(self)
        for f, n, fl in _parse(data):
            self[f] = n, fl

    def __setitem__(self, k, v):
        node, flag = v
        assert node is not None
        if len(node) > 21:
            node = node[:21] # match c implementation behavior
        dict.__setitem__(self, k, (node, flag))

    def __iter__(self):
        return iter(sorted(dict.keys(self)))

    def iterkeys(self):
        return iter(sorted(dict.keys(self)))

    def iterentries(self):
        return ((f, e[0], e[1]) for f, e in sorted(self.iteritems()))

    def copy(self):
        c = _lazymanifest('')
        c.update(self)
        return c

    def diff(self, m2, clean=False):
        '''Finds changes between the current manifest and m2.'''
        diff = {}

        for fn, e1 in self.iteritems():
            if fn not in m2:
                diff[fn] = e1, (None, '')
            else:
                e2 = m2[fn]
                if e1 != e2:
                    diff[fn] = e1, e2
                elif clean:
                    diff[fn] = None

        for fn, e2 in m2.iteritems():
            if fn not in self:
                diff[fn] = (None, ''), e2

        return diff

    def filtercopy(self, filterfn):
        c = _lazymanifest('')
        for f, n, fl in self.iterentries():
            if filterfn(f):
                c[f] = n, fl
        return c

    def text(self):
        """Get the full data of this manifest as a bytestring."""
        return _textv1(self.iterentries())

try:
    _lazymanifest = parsers.lazymanifest
except AttributeError:
    pass

class manifestdict(object):
    def __init__(self, data=''):
        if data.startswith('\0'):
            #_lazymanifest can not parse v2
            self._lm = _lazymanifest('')
            for f, n, fl in _parsev2(data):
                self._lm[f] = n, fl
        else:
            self._lm = _lazymanifest(data)

    def __getitem__(self, key):
        return self._lm[key][0]

    def find(self, key):
        return self._lm[key]

    def __len__(self):
        return len(self._lm)

    def __setitem__(self, key, node):
        self._lm[key] = node, self.flags(key, '')

    def __contains__(self, key):
        return key in self._lm

    def __delitem__(self, key):
        del self._lm[key]

    def __iter__(self):
        return self._lm.__iter__()

    def iterkeys(self):
        return self._lm.iterkeys()

    def keys(self):
        return list(self.iterkeys())

    def filesnotin(self, m2):
        '''Set of files in this manifest that are not in the other'''
        files = set(self)
        files.difference_update(m2)
        return files

    @propertycache
    def _dirs(self):
        return util.dirs(self)

    def dirs(self):
        return self._dirs

    def hasdir(self, dir):
        return dir in self._dirs

    def walk(self, match):
        '''Generates matching file names.

        Equivalent to manifest.matches(match).iterkeys(), but without creating
        an entirely new manifest.

        It also reports nonexistent files by marking them bad with match.bad().
        '''
        fset = set(match.files())

        # avoid the entire walk if we're only looking for specific files
        if fset and not match.anypats() and util.all(fn in self for fn in fset):
            for fn in sorted(fset):
                yield fn
            raise StopIteration

        for fn in self:
            if fn in fset:
                # specified pattern is the exact name
                fset.remove(fn)
            if match(fn):
                yield fn

        # for dirstate.walk, files=['.'] means "walk the whole tree".
        # follow that here, too
        fset.discard('.')

        for fn in sorted(fset):
            if not self.hasdir(fn):
                match.bad(fn, None)

    def matches(self, match):
        '''generate a new manifest filtered by the match argument'''
        if match.always():
            return self.copy()

        files = match.files()
        if (len(files) < 100 and (match.isexact() or
            (not match.anypats() and util.all(fn in self for fn in files)))):
            m = manifestdict()
            lm = self._lm
            for fn in match.files():
                if fn in lm:
                    m._lm[fn] = lm[fn]
            return m

        m = manifestdict('')
        m._lm = self._lm.filtercopy(match)
        return m

    def diff(self, m2, clean=False):
        '''Finds changes between the current manifest and m2.

        Args:
          m2: the manifest to which this manifest should be compared.
          clean: if true, include files unchanged between these manifests
                 with a None value in the returned dictionary.

        The result is returned as a dict with filename as key and
        values of the form ((n1,fl1),(n2,fl2)), where n1/n2 is the
        nodeid in the current/other manifest and fl1/fl2 is the flag
        in the current/other manifest. Where the file does not exist,
        the nodeid will be None and the flags will be the empty
        string.
        '''
        return self._lm.diff(m2._lm, clean)

    def setflag(self, key, flag):
        self._lm[key] = self[key], flag

    def get(self, key, default=None):
        try:
            return self._lm[key][0]
        except KeyError:
            return default

    def flags(self, key, default=''):
        try:
            return self._lm[key][1]
        except KeyError:
            return default

    def copy(self):
        c = manifestdict('')
        c._lm = self._lm.copy()
        return c

    def iteritems(self):
        return (x[:2] for x in self._lm.iterentries())

    def text(self, usemanifestv2=False):
        if usemanifestv2:
            return _textv2(self._lm.iterentries())
        else:
            # use (probably) native version for v1
            return self._lm.text()

    def fastdelta(self, base, changes):
        """Given a base manifest text as an array.array and a list of changes
        relative to that text, compute a delta that can be used by revlog.
        """
        delta = []
        dstart = None
        dend = None
        dline = [""]
        start = 0
        # zero copy representation of base as a buffer
        addbuf = util.buffer(base)

        # start with a readonly loop that finds the offset of
        # each line and creates the deltas
        for f, todelete in changes:
            # bs will either be the index of the item or the insert point
            start, end = _msearch(addbuf, f, start)
            if not todelete:
                h, fl = self._lm[f]
                l = "%s\0%s%s\n" % (f, revlog.hex(h), fl)
            else:
                if start == end:
                    # item we want to delete was not found, error out
                    raise AssertionError(
                            _("failed to remove %s from manifest") % f)
                l = ""
            if dstart is not None and dstart <= start and dend >= start:
                if dend < end:
                    dend = end
                if l:
                    dline.append(l)
            else:
                if dstart is not None:
                    delta.append([dstart, dend, "".join(dline)])
                dstart = start
                dend = end
                dline = [l]

        if dstart is not None:
            delta.append([dstart, dend, "".join(dline)])
        # apply the delta to the base, and get a delta for addrevision
        deltatext, arraytext = _addlistdelta(base, delta)
        return arraytext, deltatext

def _msearch(m, s, lo=0, hi=None):
    '''return a tuple (start, end) that says where to find s within m.

    If the string is found m[start:end] are the line containing
    that string.  If start == end the string was not found and
    they indicate the proper sorted insertion point.

    m should be a buffer or a string
    s is a string'''
    def advance(i, c):
        while i < lenm and m[i] != c:
            i += 1
        return i
    if not s:
        return (lo, lo)
    lenm = len(m)
    if not hi:
        hi = lenm
    while lo < hi:
        mid = (lo + hi) // 2
        start = mid
        while start > 0 and m[start - 1] != '\n':
            start -= 1
        end = advance(start, '\0')
        if m[start:end] < s:
            # we know that after the null there are 40 bytes of sha1
            # this translates to the bisect lo = mid + 1
            lo = advance(end + 40, '\n') + 1
        else:
            # this translates to the bisect hi = mid
            hi = start
    end = advance(lo, '\0')
    found = m[lo:end]
    if s == found:
        # we know that after the null there are 40 bytes of sha1
        end = advance(end + 40, '\n')
        return (lo, end + 1)
    else:
        return (lo, lo)

def _checkforbidden(l):
    """Check filenames for illegal characters."""
    for f in l:
        if '\n' in f or '\r' in f:
            raise error.RevlogError(
                _("'\\n' and '\\r' disallowed in filenames: %r") % f)


# apply the changes collected during the bisect loop to our addlist
# return a delta suitable for addrevision
def _addlistdelta(addlist, x):
    # for large addlist arrays, building a new array is cheaper
    # than repeatedly modifying the existing one
    currentposition = 0
    newaddlist = array.array('c')

    for start, end, content in x:
        newaddlist += addlist[currentposition:start]
        if content:
            newaddlist += array.array('c', content)

        currentposition = end

    newaddlist += addlist[currentposition:]

    deltatext = "".join(struct.pack(">lll", start, end, len(content))
                   + content for start, end, content in x)
    return deltatext, newaddlist

def _splittopdir(f):
    if '/' in f:
        dir, subpath = f.split('/', 1)
        return dir + '/', subpath
    else:
        return '', f

class treemanifest(object):
    def __init__(self, dir='', text=''):
        self._dir = dir
        self._dirs = {}
        # Using _lazymanifest here is a little slower than plain old dicts
        self._files = {}
        self._flags = {}
        for f, n, fl in _parse(text):
            self[f] = n
            if fl:
                self.setflag(f, fl)

    def _subpath(self, path):
        return self._dir + path

    def __len__(self):
        size = len(self._files)
        for m in self._dirs.values():
            size += m.__len__()
        return size

    def _isempty(self):
        return (not self._files and (not self._dirs or
                util.all(m._isempty() for m in self._dirs.values())))

    def __str__(self):
        return '<treemanifest dir=%s>' % self._dir

    def iteritems(self):
        for p, n in sorted(self._dirs.items() + self._files.items()):
            if p in self._files:
                yield self._subpath(p), n
            else:
                for f, sn in n.iteritems():
                    yield f, sn

    def iterkeys(self):
        for p in sorted(self._dirs.keys() + self._files.keys()):
            if p in self._files:
                yield self._subpath(p)
            else:
                for f in self._dirs[p].iterkeys():
                    yield f

    def keys(self):
        return list(self.iterkeys())

    def __iter__(self):
        return self.iterkeys()

    def __contains__(self, f):
        if f is None:
            return False
        dir, subpath = _splittopdir(f)
        if dir:
            if dir not in self._dirs:
                return False
            return self._dirs[dir].__contains__(subpath)
        else:
            return f in self._files

    def get(self, f, default=None):
        dir, subpath = _splittopdir(f)
        if dir:
            if dir not in self._dirs:
                return default
            return self._dirs[dir].get(subpath, default)
        else:
            return self._files.get(f, default)

    def __getitem__(self, f):
        dir, subpath = _splittopdir(f)
        if dir:
            return self._dirs[dir].__getitem__(subpath)
        else:
            return self._files[f]

    def flags(self, f):
        dir, subpath = _splittopdir(f)
        if dir:
            if dir not in self._dirs:
                return ''
            return self._dirs[dir].flags(subpath)
        else:
            if f in self._dirs:
                return ''
            return self._flags.get(f, '')

    def find(self, f):
        dir, subpath = _splittopdir(f)
        if dir:
            return self._dirs[dir].find(subpath)
        else:
            return self._files[f], self._flags.get(f, '')

    def __delitem__(self, f):
        dir, subpath = _splittopdir(f)
        if dir:
            self._dirs[dir].__delitem__(subpath)
            # If the directory is now empty, remove it
            if self._dirs[dir]._isempty():
                del self._dirs[dir]
        else:
            del self._files[f]
            if f in self._flags:
                del self._flags[f]

    def __setitem__(self, f, n):
        assert n is not None
        dir, subpath = _splittopdir(f)
        if dir:
            if dir not in self._dirs:
                self._dirs[dir] = treemanifest(self._subpath(dir))
            self._dirs[dir].__setitem__(subpath, n)
        else:
            self._files[f] = n[:21] # to match manifestdict's behavior

    def setflag(self, f, flags):
        """Set the flags (symlink, executable) for path f."""
        dir, subpath = _splittopdir(f)
        if dir:
            if dir not in self._dirs:
                self._dirs[dir] = treemanifest(self._subpath(dir))
            self._dirs[dir].setflag(subpath, flags)
        else:
            self._flags[f] = flags

    def copy(self):
        copy = treemanifest(self._dir)
        for d in self._dirs:
            copy._dirs[d] = self._dirs[d].copy()
        copy._files = dict.copy(self._files)
        copy._flags = dict.copy(self._flags)
        return copy

    def filesnotin(self, m2):
        '''Set of files in this manifest that are not in the other'''
        files = set()
        def _filesnotin(t1, t2):
            for d, m1 in t1._dirs.iteritems():
                if d in t2._dirs:
                    m2 = t2._dirs[d]
                    _filesnotin(m1, m2)
                else:
                    files.update(m1.iterkeys())

            for fn in t1._files.iterkeys():
                if fn not in t2._files:
                    files.add(t1._subpath(fn))

        _filesnotin(self, m2)
        return files

    @propertycache
    def _alldirs(self):
        return util.dirs(self)

    def dirs(self):
        return self._alldirs

    def hasdir(self, dir):
        topdir, subdir = _splittopdir(dir)
        if topdir:
            if topdir in self._dirs:
                return self._dirs[topdir].hasdir(subdir)
            return False
        return (dir + '/') in self._dirs

    def walk(self, match):
        '''Generates matching file names.

        Equivalent to manifest.matches(match).iterkeys(), but without creating
        an entirely new manifest.

        It also reports nonexistent files by marking them bad with match.bad().
        '''
        fset = set(match.files())

        for fn in self._walk(match):
            if fn in fset:
                # specified pattern is the exact name
                fset.remove(fn)
            yield fn

        # for dirstate.walk, files=['.'] means "walk the whole tree".
        # follow that here, too
        fset.discard('.')

        for fn in sorted(fset):
            if not self.hasdir(fn):
                match.bad(fn, None)

    def _walk(self, match, alldirs=False):
        '''Recursively generates matching file names for walk().

        Will visit all subdirectories if alldirs is True, otherwise it will
        only visit subdirectories for which match.visitdir is True.'''

        if not alldirs:
            # substring to strip trailing slash
            visit = match.visitdir(self._dir[:-1] or '.')
            if not visit:
                return
            alldirs = (visit == 'all')

        # yield this dir's files and walk its submanifests
        for p in sorted(self._dirs.keys() + self._files.keys()):
            if p in self._files:
                fullp = self._subpath(p)
                if match(fullp):
                    yield fullp
            else:
                for f in self._dirs[p]._walk(match, alldirs):
                    yield f

    def matches(self, match):
        '''generate a new manifest filtered by the match argument'''
        if match.always():
            return self.copy()

        return self._matches(match)

    def _matches(self, match, alldirs=False):
        '''recursively generate a new manifest filtered by the match argument.

        Will visit all subdirectories if alldirs is True, otherwise it will
        only visit subdirectories for which match.visitdir is True.'''

        ret = treemanifest(self._dir)
        if not alldirs:
            # substring to strip trailing slash
            visit = match.visitdir(self._dir[:-1] or '.')
            if not visit:
                return ret
            alldirs = (visit == 'all')

        for fn in self._files:
            fullp = self._subpath(fn)
            if not match(fullp):
                continue
            ret._files[fn] = self._files[fn]
            if fn in self._flags:
                ret._flags[fn] = self._flags[fn]

        for dir, subm in self._dirs.iteritems():
            m = subm._matches(match, alldirs)
            if not m._isempty():
                ret._dirs[dir] = m

        return ret

    def diff(self, m2, clean=False):
        '''Finds changes between the current manifest and m2.

        Args:
          m2: the manifest to which this manifest should be compared.
          clean: if true, include files unchanged between these manifests
                 with a None value in the returned dictionary.

        The result is returned as a dict with filename as key and
        values of the form ((n1,fl1),(n2,fl2)), where n1/n2 is the
        nodeid in the current/other manifest and fl1/fl2 is the flag
        in the current/other manifest. Where the file does not exist,
        the nodeid will be None and the flags will be the empty
        string.
        '''
        result = {}
        emptytree = treemanifest()
        def _diff(t1, t2):
            for d, m1 in t1._dirs.iteritems():
                m2 = t2._dirs.get(d, emptytree)
                _diff(m1, m2)

            for d, m2 in t2._dirs.iteritems():
                if d not in t1._dirs:
                    _diff(emptytree, m2)

            for fn, n1 in t1._files.iteritems():
                fl1 = t1._flags.get(fn, '')
                n2 = t2._files.get(fn, None)
                fl2 = t2._flags.get(fn, '')
                if n1 != n2 or fl1 != fl2:
                    result[t1._subpath(fn)] = ((n1, fl1), (n2, fl2))
                elif clean:
                    result[t1._subpath(fn)] = None

            for fn, n2 in t2._files.iteritems():
                if fn not in t1._files:
                    fl2 = t2._flags.get(fn, '')
                    result[t2._subpath(fn)] = ((None, ''), (n2, fl2))

        _diff(self, m2)
        return result

    def text(self, usemanifestv2=False):
        """Get the full data of this manifest as a bytestring."""
        flags = self.flags
        return _text(((f, self[f], flags(f)) for f in self.keys()),
                     usemanifestv2)

class manifest(revlog.revlog):
    def __init__(self, opener):
        # During normal operations, we expect to deal with not more than four
        # revs at a time (such as during commit --amend). When rebasing large
        # stacks of commits, the number can go up, hence the config knob below.
        cachesize = 4
        usetreemanifest = False
        usemanifestv2 = False
        opts = getattr(opener, 'options', None)
        if opts is not None:
            cachesize = opts.get('manifestcachesize', cachesize)
            usetreemanifest = opts.get('usetreemanifest', usetreemanifest)
            usemanifestv2 = opts.get('manifestv2', usemanifestv2)
        self._mancache = util.lrucachedict(cachesize)
        revlog.revlog.__init__(self, opener, "00manifest.i")
        self._usetreemanifest = usetreemanifest
        self._usemanifestv2 = usemanifestv2

    def _newmanifest(self, data=''):
        if self._usetreemanifest:
            return treemanifest('', data)
        return manifestdict(data)

    def _slowreaddelta(self, node):
        r0 = self.deltaparent(self.rev(node))
        m0 = self.read(self.node(r0))
        m1 = self.read(node)
        md = self._newmanifest()
        for f, ((n0, fl0), (n1, fl1)) in m0.diff(m1).iteritems():
            if n1:
                md[f] = n1
                if fl1:
                    md.setflag(f, fl1)
        return md

    def readdelta(self, node):
        if self._usemanifestv2 or self._usetreemanifest:
            return self._slowreaddelta(node)
        r = self.rev(node)
        d = mdiff.patchtext(self.revdiff(self.deltaparent(r), r))
        return self._newmanifest(d)

    def readfast(self, node):
        '''use the faster of readdelta or read'''
        r = self.rev(node)
        deltaparent = self.deltaparent(r)
        if deltaparent != revlog.nullrev and deltaparent in self.parentrevs(r):
            return self.readdelta(node)
        return self.read(node)

    def read(self, node):
        if node == revlog.nullid:
            return self._newmanifest() # don't upset local cache
        if node in self._mancache:
            return self._mancache[node][0]
        text = self.revision(node)
        arraytext = array.array('c', text)
        m = self._newmanifest(text)
        self._mancache[node] = (m, arraytext)
        return m

    def find(self, node, f):
        '''look up entry for a single file efficiently.
        return (node, flags) pair if found, (None, None) if not.'''
        m = self.read(node)
        try:
            return m.find(f)
        except KeyError:
            return None, None

    def add(self, m, transaction, link, p1, p2, added, removed):
        if (p1 in self._mancache and not self._usetreemanifest
            and not self._usemanifestv2):
            # If our first parent is in the manifest cache, we can
            # compute a delta here using properties we know about the
            # manifest up-front, which may save time later for the
            # revlog layer.

            _checkforbidden(added)
            # combine the changed lists into one list for sorting
            work = [(x, False) for x in added]
            work.extend((x, True) for x in removed)
            # this could use heapq.merge() (from Python 2.6+) or equivalent
            # since the lists are already sorted
            work.sort()

            arraytext, deltatext = m.fastdelta(self._mancache[p1][1], work)
            cachedelta = self.rev(p1), deltatext
            text = util.buffer(arraytext)
        else:
            # The first parent manifest isn't already loaded, so we'll
            # just encode a fulltext of the manifest and pass that
            # through to the revlog layer, and let it handle the delta
            # process.
            text = m.text(self._usemanifestv2)
            arraytext = array.array('c', text)
            cachedelta = None

        n = self.addrevision(text, transaction, link, p1, p2, cachedelta)
        self._mancache[n] = (m, arraytext)

        return n