mercurial/pure/parsers.py

destupdate: move the check related to the "clean" logic in the function

We want this function to exactly predict the behavior for update. Moreover, we
would like to remove all high level behavior logic out of the merge module so
this is a step forward.

Now that the 'destupdate' function both compute and validate the destination, we
can directly use it at the command level, ensuring that the 'hg update' command
never call 'merge.update' without a defined destination. This is a first (but
significant) step toward having 'merge.update' always feed with a properly
validated destination and free of high level logic.

# parsers.py - Python implementation of parsers.c
#
# Copyright 2009 Matt Mackall <[e-mail]> and others
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from mercurial.node import nullid
import struct, zlib, cStringIO

_pack = struct.pack
_unpack = struct.unpack
_compress = zlib.compress
_decompress = zlib.decompress

# Some code below makes tuples directly because it's more convenient. However,
# code outside this module should always use dirstatetuple.
def dirstatetuple(*x):
    # x is a tuple
    return x

def parse_index2(data, inline):
    def gettype(q):
        return int(q & 0xFFFF)

    def offset_type(offset, type):
        return long(long(offset) << 16 | type)

    indexformatng = ">Qiiiiii20s12x"

    s = struct.calcsize(indexformatng)
    index = []
    cache = None
    off = 0

    l = len(data) - s
    append = index.append
    if inline:
        cache = (0, data)
        while off <= l:
            e = _unpack(indexformatng, data[off:off + s])
            append(e)
            if e[1] < 0:
                break
            off += e[1] + s
    else:
        while off <= l:
            e = _unpack(indexformatng, data[off:off + s])
            append(e)
            off += s

    if off != len(data):
        raise ValueError('corrupt index file')

    if index:
        e = list(index[0])
        type = gettype(e[0])
        e[0] = offset_type(0, type)
        index[0] = tuple(e)

    # add the magic null revision at -1
    index.append((0, 0, 0, -1, -1, -1, -1, nullid))

    return index, cache

def parse_dirstate(dmap, copymap, st):
    parents = [st[:20], st[20: 40]]
    # dereference fields so they will be local in loop
    format = ">cllll"
    e_size = struct.calcsize(format)
    pos1 = 40
    l = len(st)

    # the inner loop
    while pos1 < l:
        pos2 = pos1 + e_size
        e = _unpack(">cllll", st[pos1:pos2]) # a literal here is faster
        pos1 = pos2 + e[4]
        f = st[pos2:pos1]
        if '\0' in f:
            f, c = f.split('\0')
            copymap[f] = c
        dmap[f] = e[:4]
    return parents

def pack_dirstate(dmap, copymap, pl, now):
    now = int(now)
    cs = cStringIO.StringIO()
    write = cs.write
    write("".join(pl))
    for f, e in dmap.iteritems():
        if e[0] == 'n' and e[3] == now:
            # The file was last modified "simultaneously" with the current
            # write to dirstate (i.e. within the same second for file-
            # systems with a granularity of 1 sec). This commonly happens
            # for at least a couple of files on 'update'.
            # The user could change the file without changing its size
            # within the same second. Invalidate the file's mtime in
            # dirstate, forcing future 'status' calls to compare the
            # contents of the file if the size is the same. This prevents
            # mistakenly treating such files as clean.
            e = dirstatetuple(e[0], e[1], e[2], -1)
            dmap[f] = e

        if f in copymap:
            f = "%s\0%s" % (f, copymap[f])
        e = _pack(">cllll", e[0], e[1], e[2], e[3], len(f))
        write(e)
        write(f)
    return cs.getvalue()