Mercurial > hg
view mercurial/revlogutils/constants.py @ 39814:d059cb669632
wireprotov2: allow multiple fields to follow revision maps
The *data wire protocol commands emit a series of CBOR values.
Because revision/delta data may be large, their data is emitted
outside the map as a top-level bytestring value.
Before this commit, we'd emit a single optional bytestring
value after the revision descriptor map. This got the job done.
But it was limiting in that we could only send a single field.
And, it required the consumer to know that the presence of a
key in the map implied the existence of a following bytestring
value.
This commit changes the encoding strategy so top-level bytestring
values in the stream are explicitly denoted in a "fieldsfollowing"
key. This key contains an array defining what fields that follow
and the expected size of each field.
By defining things this way, we can easily send N bytestring
values without any ambiguity about their order. In addition,
clients only need to know how to parse ``fieldsfollowing`` to
know if extra values are present.
Because this breaks backwards compatibility, we've bumped the version
number of the wire protocol version 2 API endpoint.
Differential Revision: https://phab.mercurial-scm.org/D4620
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Thu, 20 Sep 2018 12:57:23 -0700 |
parents | b66ea3fc3a86 |
children | 8e398628a3f2 |
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# revlogdeltas.py - constant used for revlog logic # # Copyright 2005-2007 Matt Mackall <mpm@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 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 SPARSE_REVLOG_MAX_CHAIN_LENGTH = 1000