# manifest.py - manifest revision class for mercurial

#

# Copyright 2005-2007 Matt Mackall <mpm@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 i18n import _

import mdiff, parsers, error, revlog

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 set(self, f, flags):

        self._flags[f] = flags

    def copy(self):

        return manifestdict(self, dict.copy(self._flags))

class manifest(revlog.revlog):

    def __init__(self, opener):

        self._mancache = None

        revlog.revlog.__init__(self, opener, "00manifest.i")

    def parse(self, lines):

        mfdict = manifestdict()

        parsers.parse_manifest(mfdict, mfdict._flags, lines)

        return mfdict

    def readdelta(self, node):

        r = self.rev(node)

        return self.parse(mdiff.patchtext(self.revdiff(self.deltaparent(r), r)))

    def read(self, node):

        if node == revlog.nullid:

            return manifestdict() # don't upset local cache

        if self._mancache and self._mancache[0] == node:

            return self._mancache[1]

        text = self.revision(node)

        arraytext = array.array('c', text)

        mapping = self.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.  This was

        taken from bisect_left, and modified to find line start/end as

        it goes along.

        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 self._mancache and self._mancache[0] == node:

            return self._mancache[1].get(f), self._mancache[1].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=None, p2=None,

            changed=None):

        # apply the changes collected during the bisect loop to our addlist

        # return a delta suitable for addrevision

        def addlistdelta(addlist, x):

            # start from the bottom up

            # so changes to the offsets don't mess things up.

            for start, end, content in reversed(x):

                if content:

                    addlist[start:end] = array.array('c', content)

                else:

                    del addlist[start:end]

            return "".join(struct.pack(">lll", start, end, len(content)) + content

                           for start, end, content in x)

        def checkforbidden(l):

            for f in l:

                if '\n' in f or '\r' in f:

                    raise error.RevlogError(

                        _("'\\n' and '\\r' disallowed in filenames: %r") % f)

        # if we're using the cache, make sure it is valid and

        # parented by the same node we're diffing against

        if not (changed and self._mancache and p1 and self._mancache[0] == p1):

            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\000%s%s\n" % (f, hex(map[f]), flags(f))

                           for f in files)

            arraytext = array.array('c', text)

            cachedelta = None

        else:

            added, removed = changed

            addlist = self._mancache[2]

            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 python2.6+) 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 = 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\000%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 != None and dstart <= start and dend >= start:

                    if dend < end:

                        dend = end

                    if l:

                        dline.append(l)

                else:

                    if dstart != None:

                        delta.append([dstart, dend, "".join(dline)])

                    dstart = start

                    dend = end

                    dline = [l]

            if dstart != None:

                delta.append([dstart, dend, "".join(dline)])

            # apply the delta to the addlist, and get a delta for addrevision

            cachedelta = (self.rev(p1), addlistdelta(addlist, delta))

            arraytext = addlist

            text = buffer(arraytext)

        n = self.addrevision(text, transaction, link, p1, p2, cachedelta)

        self._mancache = (n, map, arraytext)

        return n