view mercurial/manifest.py @ 22806:65ccc733d58e

getlogrevs: remove user of baseset.append

A `baseset` has multiple cached results and will get even more in the future.
Making it an object "populated once" like the other smartsets makes it both safer
and simpler. The append method will be removed at some point.

# 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, dicthelpers
import array, struct

class manifestdict(dict):
    def __init__(self, mapping=None, flags=None):
        if mapping is None:
            mapping = {}
        if flags is None:
            flags = {}
        dict.__init__(self, mapping)
        self._flags = flags
    def flags(self, f):
        return self._flags.get(f, "")
    def withflags(self):
        return set(self._flags.keys())
    def set(self, f, flags):
        self._flags[f] = flags
    def copy(self):
        return manifestdict(self, dict.copy(self._flags))
    def intersectfiles(self, files):
        '''make a new manifestdict with the intersection of self with files

        The algorithm assumes that files is much smaller than self.'''
        ret = manifestdict()
        for fn in files:
            if fn in self:
                ret[fn] = self[fn]
                flags = self._flags.get(fn, None)
                if flags:
                    ret._flags[fn] = flags
        return ret
    def flagsdiff(self, d2):
        return dicthelpers.diff(self._flags, d2._flags, "")


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 _parse(lines):
    mfdict = manifestdict()
    parsers.parse_manifest(mfdict, mfdict._flags, lines)
    return mfdict

class manifest(revlog.revlog):
    def __init__(self, opener):
        # we expect to deal with not more than four revs at a time,
        # during a commit --amend
        self._mancache = util.lrucachedict(4)
        revlog.revlog.__init__(self, opener, "00manifest.i")

    def readdelta(self, node):
        r = self.rev(node)
        return _parse(mdiff.patchtext(self.revdiff(self.deltaparent(r), r)))

    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 manifestdict() # don't upset local cache
        if node in self._mancache:
            return self._mancache[node][0]
        text = self.revision(node)
        arraytext = array.array('c', text)
        mapping = _parse(text)
        self._mancache[node] = (mapping, arraytext)
        return mapping

    def _search(self, 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 find(self, node, f):
        '''look up entry for a single file efficiently.
        return (node, flags) pair if found, (None, None) if not.'''
        if node in self._mancache:
            mapping = self._mancache[node][0]
            return mapping.get(f), mapping.flags(f)
        text = self.revision(node)
        start, end = self._search(text, f)
        if start == end:
            return None, None
        l = text[start:end]
        f, n = l.split('\0')
        return revlog.bin(n[:40]), n[40:-1]

    def add(self, map, transaction, link, p1, p2, added, removed):
        if p1 in self._mancache:
            # 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.
            addlist = self._mancache[p1][1]

            _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()

            delta = []
            dstart = None
            dend = None
            dline = [""]
            start = 0
            # zero copy representation of addlist as a buffer
            addbuf = util.buffer(addlist)

            # start with a readonly loop that finds the offset of
            # each line and creates the deltas
            for f, todelete in work:
                # bs will either be the index of the item or the insert point
                start, end = self._search(addbuf, f, start)
                if not todelete:
                    l = "%s\0%s%s\n" % (f, revlog.hex(map[f]), map.flags(f))
                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 addlist, and get a delta for addrevision
            deltatext, addlist = _addlistdelta(addlist, delta)
            cachedelta = (self.rev(p1), deltatext)
            arraytext = addlist
            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.
            files = sorted(map)
            _checkforbidden(files)

            # if this is changed to support newlines in filenames,
            # be sure to check the templates/ dir again (especially *-raw.tmpl)
            hex, flags = revlog.hex, map.flags
            text = ''.join("%s\0%s%s\n" % (f, hex(map[f]), flags(f))
                           for f in files)
            arraytext = array.array('c', text)
            cachedelta = None

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

        return n