Mercurial > hg
view mercurial/node.py @ 49232:4c57ce494a4e
worker: stop relying on garbage collection to release memoryview
On CPython, before resizing the bytearray, all memoryviews referencing it must
be released. Before this change, we ensured that all references to them were
deleted. On CPython, this was enough to set the reference count to zero, which
results in garbage collecting and releasing them.
On PyPy, releasing the memoryviews is not necessary because they are implemented
differently. If it would be necessary however, ensuring that all references are
deleted would not be suffient because PyPy doesn’t use reference counting.
By using with statements that take care of releasing the memoryviews, we ensure
that the bytearray is resizable without relying on implementation details. So
while this doesn’t fix any observable bug, it increases compatiblity with other
and future Python implementations.
author | Manuel Jacob <me@manueljacob.de> |
---|---|
date | Sat, 21 May 2022 23:31:30 +0200 |
parents | 642e31cb55f0 |
children | 63fd0282ad40 |
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# node.py - basic nodeid manipulation for mercurial # # Copyright 2005, 2006 Olivia Mackall <olivia@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. 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) def short(node): return hex(node[:6]) nullrev = -1 # pseudo identifier for working directory # (experimental, so don't add too many dependencies on it) wdirrev = 0x7FFFFFFF class sha1nodeconstants: nodelen = 20 # In hex, this is '0000000000000000000000000000000000000000' nullid = b"\0" * nodelen nullhex = hex(nullid) # Phony node value to stand-in for new files in some uses of # manifests. # In hex, this is '2121212121212121212121212121212121212121' newnodeid = b'!!!!!!!!!!!!!!!!!!!!' # In hex, this is '3030303030303030303030303030306164646564' addednodeid = b'000000000000000added' # In hex, this is '3030303030303030303030306d6f646966696564' modifiednodeid = b'000000000000modified' wdirfilenodeids = {newnodeid, addednodeid, modifiednodeid} # pseudo identifier for working directory # (experimental, so don't add too many dependencies on it) # In hex, this is 'ffffffffffffffffffffffffffffffffffffffff' wdirid = b"\xff" * nodelen wdirhex = hex(wdirid) # legacy starting point for porting modules nullid = sha1nodeconstants.nullid nullhex = sha1nodeconstants.nullhex newnodeid = sha1nodeconstants.newnodeid addednodeid = sha1nodeconstants.addednodeid modifiednodeid = sha1nodeconstants.modifiednodeid wdirfilenodeids = sha1nodeconstants.wdirfilenodeids wdirid = sha1nodeconstants.wdirid wdirhex = sha1nodeconstants.wdirhex