Mercurial > hg
view mercurial/node.py @ 42136:10a6725dca6e
compression: introduce an official `zstd-revlog` requirement
This requirement supersedes `exp-compression-zstd`. However, we keep support for
the old requirement.
Strictly speaking, we do not need to add a new requirement, there are no logic
change making "new" repo incompatible with mercurial client using a version
that support `exp-compression-zstd`.
The choice to introduce a new requirement is motivated by the following:
* The previous requirement was explicitly "experimental". Using it by default
could confuse users.
* adding support for a hypothetical third compression engine will requires new
code, and will comes with its own requirement tool.
* We won't use it as the default for a while since I do not think we support
zstd on all platform. I can imagine we'll gain another (unrelated but on my
default) requirement by the time we turn this zstd by default.
author | Pierre-Yves David <pierre-yves.david@octobus.net> |
---|---|
date | Wed, 27 Mar 2019 18:27:03 +0100 |
parents | 1e7a462cb946 |
children | 57875cf423c9 |
line wrap: on
line source
# node.py - basic nodeid manipulation for mercurial # # Copyright 2005, 2006 Matt Mackall <mpm@selenic.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from __future__ import absolute_import import binascii # This ugly style has a noticeable effect in manifest parsing hex = binascii.hexlify # Adapt to Python 3 API changes. If this ends up showing up in # profiles, we can use this version only on Python 3, and forward # binascii.unhexlify like we used to on Python 2. def bin(s): try: return binascii.unhexlify(s) except binascii.Error as e: raise TypeError(e) nullrev = -1 # In hex, this is '0000000000000000000000000000000000000000' nullid = b"\0" * 20 nullhex = hex(nullid) # Phony node value to stand-in for new files in some uses of # manifests. # In hex, this is '2121212121212121212121212121212121212121' newnodeid = '!!!!!!!!!!!!!!!!!!!!' # In hex, this is '3030303030303030303030303030306164646564' addednodeid = '000000000000000added' # In hex, this is '3030303030303030303030306d6f646966696564' modifiednodeid = '000000000000modified' wdirfilenodeids = {newnodeid, addednodeid, modifiednodeid} # pseudo identifiers for working directory # (they are experimental, so don't add too many dependencies on them) wdirrev = 0x7fffffff # In hex, this is 'ffffffffffffffffffffffffffffffffffffffff' wdirid = b"\xff" * 20 wdirhex = hex(wdirid) def short(node): return hex(node[:6])