Mercurial > hg
view mercurial/revlogutils/constants.py @ 46857:cc65cea90edb
revlog: move the details of revlog "v1" index inside revlog.utils.constants
The revlog module is quite large and this kind of format information would handy
for other module. So let us start to gather this information about the format in
a more appropriate place.
We update various reference to this information to use the new "source of truth"
in the process.
Differential Revision: https://phab.mercurial-scm.org/D10304
author | Pierre-Yves David <pierre-yves.david@octobus.net> |
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date | Mon, 05 Apr 2021 12:21:01 +0200 |
parents | 34e1fa4b548a |
children | 85e3a630cad9 |
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# revlogdeltas.py - constant used for revlog logic # # Copyright 2005-2007 Olivia Mackall <olivia@selenic.com> # Copyright 2018 Octobus <contact@octobus.net> # # 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 import struct from ..interfaces import repository ### main revlog header ## revlog version REVLOGV0 = 0 REVLOGV1 = 1 # Dummy value until file format is finalized. REVLOGV2 = 0xDEAD ## global revlog header flags # Shared across v1 and v2. FLAG_INLINE_DATA = 1 << 16 # Only used by v1, implied by v2. 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 = FLAG_INLINE_DATA ### individual entry ## index v0: # 4 bytes: offset # 4 bytes: compressed length # 4 bytes: base rev # 4 bytes: link rev # 20 bytes: parent 1 nodeid # 20 bytes: parent 2 nodeid # 20 bytes: nodeid INDEX_ENTRY_V0 = struct.Struct(b">4l20s20s20s") ## index v1 # 6 bytes: offset # 2 bytes: flags # 4 bytes: compressed length # 4 bytes: uncompressed length # 4 bytes: base rev # 4 bytes: link rev # 4 bytes: parent 1 rev # 4 bytes: parent 2 rev # 32 bytes: nodeid INDEX_ENTRY_V1 = struct.Struct(b">Qiiiiii20s12x") assert INDEX_ENTRY_V1.size == 32 * 2 # revlog index flags # For historical reasons, revlog's internal flags were exposed via the # wire protocol and are even exposed in parts of the storage APIs. # revision has censor metadata, must be verified REVIDX_ISCENSORED = repository.REVISION_FLAG_CENSORED # revision hash does not match data (narrowhg) REVIDX_ELLIPSIS = repository.REVISION_FLAG_ELLIPSIS # revision data is stored externally REVIDX_EXTSTORED = repository.REVISION_FLAG_EXTSTORED # revision data contains extra metadata not part of the official digest REVIDX_SIDEDATA = repository.REVISION_FLAG_SIDEDATA # revision changes files in a way that could affect copy tracing. REVIDX_HASCOPIESINFO = repository.REVISION_FLAG_HASCOPIESINFO 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_SIDEDATA, REVIDX_HASCOPIESINFO, ] # bitmark for flags that could cause rawdata content change REVIDX_RAWTEXT_CHANGING_FLAGS = ( REVIDX_ISCENSORED | REVIDX_EXTSTORED | REVIDX_SIDEDATA ) SPARSE_REVLOG_MAX_CHAIN_LENGTH = 1000