comparison mercurial/revlogutils/nodemap.py @ 44335:e41a164db7a9

nodemap: track the maximum revision tracked in the nodemap

We need a simple way to detect when the on disk data contains less revision
than the index we read from disk. The docket file is meant for this, we just had
to start tracking that data.

We should also try to detect strip operation, but we will deal with this in
later changesets. Right now we are focusing on defining the API for index
supporting persistent nodemap.

Differential Revision: https://phab.mercurial-scm.org/D7888

44334:6614b301ea58

    offset = 0
    (version,) = S_VERSION.unpack(pdata[offset : offset + S_VERSION.size])
    if version != ONDISK_VERSION:
        return None
    offset += S_VERSION.size
    (uid_size,) = S_HEADER.unpack(pdata[offset : offset + S_HEADER.size])
    offset += S_HEADER.size
    docket = NodeMapDocket(pdata[offset : offset + uid_size])

    filename = _rawdata_filepath(revlog, docket)
    return docket, revlog.opener.tryread(filename)

            data = persistent_data(revlog.index)
        # EXP-TODO: if this is a cache, this should use a cache vfs, not a
        # store vfs
        with revlog.opener(datafile, b'w') as fd:
            fd.write(data)
    # EXP-TODO: if this is a cache, this should use a cache vfs, not a
    # store vfs
    with revlog.opener(revlog.nodemap_file, b'w', atomictemp=True) as fp:
        fp.write(target_docket.serialize())
    revlog._nodemap_docket = target_docket

# version 0 is experimental, no BC garantee, do no use outside of tests.
ONDISK_VERSION = 0

S_VERSION = struct.Struct(">B")
S_HEADER = struct.Struct(">B")

ID_SIZE = 8


def _make_uid():

    def __init__(self, uid=None):
        if uid is None:
            uid = _make_uid()
        self.uid = uid

    def copy(self):
        return NodeMapDocket(uid=self.uid)

    def serialize(self):
        """return serialized bytes for a docket using the passed uid"""
        data = []
        data.append(S_VERSION.pack(ONDISK_VERSION))
        data.append(S_HEADER.pack(len(self.uid)))
        data.append(self.uid)
        return b''.join(data)


def _rawdata_filepath(revlog, docket):

44335:e41a164db7a9

    offset = 0
    (version,) = S_VERSION.unpack(pdata[offset : offset + S_VERSION.size])
    if version != ONDISK_VERSION:
        return None
    offset += S_VERSION.size
    headers = S_HEADER.unpack(pdata[offset : offset + S_HEADER.size])
    uid_size, tip_rev = headers
    offset += S_HEADER.size
    docket = NodeMapDocket(pdata[offset : offset + uid_size])
    docket.tip_rev = tip_rev

    filename = _rawdata_filepath(revlog, docket)
    return docket, revlog.opener.tryread(filename)

            data = persistent_data(revlog.index)
        # EXP-TODO: if this is a cache, this should use a cache vfs, not a
        # store vfs
        with revlog.opener(datafile, b'w') as fd:
            fd.write(data)
    target_docket.tip_rev = revlog.tiprev()
    # EXP-TODO: if this is a cache, this should use a cache vfs, not a
    # store vfs
    with revlog.opener(revlog.nodemap_file, b'w', atomictemp=True) as fp:
        fp.write(target_docket.serialize())
    revlog._nodemap_docket = target_docket

# version 0 is experimental, no BC garantee, do no use outside of tests.
ONDISK_VERSION = 0

S_VERSION = struct.Struct(">B")
S_HEADER = struct.Struct(">BQ")

ID_SIZE = 8


def _make_uid():

    def __init__(self, uid=None):
        if uid is None:
            uid = _make_uid()
        self.uid = uid
        self.tip_rev = None

    def copy(self):
        new = NodeMapDocket(uid=self.uid)
        new.tip_rev = self.tip_rev
        return new

    def serialize(self):
        """return serialized bytes for a docket using the passed uid"""
        data = []
        data.append(S_VERSION.pack(ONDISK_VERSION))
        headers = (len(self.uid), self.tip_rev)
        data.append(S_HEADER.pack(*headers))
        data.append(self.uid)
        return b''.join(data)


def _rawdata_filepath(revlog, docket):