annotate mercurial/revlogutils/constants.py @ 39330:655b5b465953

revlog: split functionality related to deltas computation in a new module

The revlog module is getting big and this logic is getting more and more
advanced. Moving it to `mercurial.revlogutils.deltas` split a lot off
revlog.py and will help this logic to become less interleaved with revlog.

The code is simply moved without modification (but for namespace changes).
Refactoring and improvement will be made in later changesets.

# revlogdeltas.py - constant used for revlog logic
#
# Copyright 2005-2007 Matt Mackall <[e-mail]>
# Copyright 2018 Octobus <[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.
"""Helper class to compute deltas stored inside revlogs"""

from __future__ import absolute_import

from .. import (
    util,
)

# revlog header flags
REVLOGV0 = 0
REVLOGV1 = 1
# Dummy value until file format is finalized.
# Reminder: change the bounds check in revlog.__init__ when this is changed.
REVLOGV2 = 0xDEAD
FLAG_INLINE_DATA = (1 << 16)
FLAG_GENERALDELTA = (1 << 17)
REVLOG_DEFAULT_FLAGS = FLAG_INLINE_DATA
REVLOG_DEFAULT_FORMAT = REVLOGV1
REVLOG_DEFAULT_VERSION = REVLOG_DEFAULT_FORMAT | REVLOG_DEFAULT_FLAGS
REVLOGV1_FLAGS = FLAG_INLINE_DATA | FLAG_GENERALDELTA
REVLOGV2_FLAGS = REVLOGV1_FLAGS

# revlog index flags
REVIDX_ISCENSORED = (1 << 15) # revision has censor metadata, must be verified
REVIDX_ELLIPSIS = (1 << 14) # revision hash does not match data (narrowhg)
REVIDX_EXTSTORED = (1 << 13) # revision data is stored externally
REVIDX_DEFAULT_FLAGS = 0
# stable order in which flags need to be processed and their processors applied
REVIDX_FLAGS_ORDER = [
    REVIDX_ISCENSORED,
    REVIDX_ELLIPSIS,
    REVIDX_EXTSTORED,
]
REVIDX_KNOWN_FLAGS = util.bitsfrom(REVIDX_FLAGS_ORDER)
# bitmark for flags that could cause rawdata content change
REVIDX_RAWTEXT_CHANGING_FLAGS = REVIDX_ISCENSORED | REVIDX_EXTSTORED