mercurial/node.py
author Durham Goode <durham@fb.com>
Sat, 07 Nov 2015 16:11:49 -0800
changeset 26909 e36118815a39
parent 25962 738314da6c75
child 26980 18f50b8cbf1e
permissions -rw-r--r--
phase: improve retractboundary perf The existing retractboundary implementation computed the new boundary by walking all descendants of all existing roots and computing the new roots. This is O(commits since first root), which on long repos can be hundreds of thousands of commits. The new algorithm only updates roots that are greater than the new root locations. For common operations like commit on a repo with the earliest root several hundred thousand commits ago, this makes retractboundary go from 1 second to 0.008 seconds. I tested it by running the test suite with both implementations and checking that the root results were always the identical. There was some discussion on IRC about the safety of this (i.e. what if the new nodes are already part of the phase, etc). I've looked into it and believe this patch is safe: 1) The old existing code already filters the input nodes to only contain nodes that require retracting (i.e. we only make node X a new root if the old phase is less than the target phase), so there's no chance of us adding a unnecessary root to the phase (unless the input root is made unnecessary by another root in the same input, but see point #3). 2) Another way of thinking about this is: the only way the new algorithm would be different from the old algorithm is if it added a root that is a descendant of an old root (since the old algorithm would've caught this in the big "roots(%ln::)". At the beginning of the function, when we filter out roots that already meet the phase criteria, the *definition* of meeting the phase criteria is "not being a descendant of an existing root". Therefore, by definition none of the new roots we are processing are descendants of an existing root. 3) If two nodes are passed in as input, and one node is an ancestor of the other (and therefore the later node should not be a root), this is still caught by the 'roots(%ln::)' revset. So there's no chance of an extra root being introduced that way either.
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
8226
8b2cd04a6e97 put license and copyright info into comment blocks
Martin Geisler <mg@lazybytes.net>
parents: 8225
diff changeset
     1
# node.py - basic nodeid manipulation for mercurial
8b2cd04a6e97 put license and copyright info into comment blocks
Martin Geisler <mg@lazybytes.net>
parents: 8225
diff changeset
     2
#
8b2cd04a6e97 put license and copyright info into comment blocks
Martin Geisler <mg@lazybytes.net>
parents: 8225
diff changeset
     3
# Copyright 2005, 2006 Matt Mackall <mpm@selenic.com>
8b2cd04a6e97 put license and copyright info into comment blocks
Martin Geisler <mg@lazybytes.net>
parents: 8225
diff changeset
     4
#
8b2cd04a6e97 put license and copyright info into comment blocks
Martin Geisler <mg@lazybytes.net>
parents: 8225
diff changeset
     5
# This software may be used and distributed according to the terms of the
10263
25e572394f5c Update license to GPLv2+
Matt Mackall <mpm@selenic.com>
parents: 8226
diff changeset
     6
# GNU General Public License version 2 or any later version.
1089
142b5d5ec9cc Break apart hg.py
mpm@selenic.com
parents:
diff changeset
     7
25962
738314da6c75 node: use absolute_import
Gregory Szorc <gregory.szorc@gmail.com>
parents: 25737
diff changeset
     8
from __future__ import absolute_import
738314da6c75 node: use absolute_import
Gregory Szorc <gregory.szorc@gmail.com>
parents: 25737
diff changeset
     9
3877
abaee83ce0a6 Replace demandload with new demandimport
Matt Mackall <mpm@selenic.com>
parents: 3578
diff changeset
    10
import binascii
1089
142b5d5ec9cc Break apart hg.py
mpm@selenic.com
parents:
diff changeset
    11
3578
3b4e00cba57a Define and use nullrev (revision of nullid) instead of -1.
Thomas Arendsen Hein <thomas@intevation.de>
parents: 2859
diff changeset
    12
nullrev = -1
1089
142b5d5ec9cc Break apart hg.py
mpm@selenic.com
parents:
diff changeset
    13
nullid = "\0" * 20
142b5d5ec9cc Break apart hg.py
mpm@selenic.com
parents:
diff changeset
    14
25737
1a5211f2f87f node: define experimental identifiers for working directory
Yuya Nishihara <yuya@tcha.org>
parents: 10263
diff changeset
    15
# pseudo identifiers for working directory
1a5211f2f87f node: define experimental identifiers for working directory
Yuya Nishihara <yuya@tcha.org>
parents: 10263
diff changeset
    16
# (they are experimental, so don't add too many dependencies on them)
1a5211f2f87f node: define experimental identifiers for working directory
Yuya Nishihara <yuya@tcha.org>
parents: 10263
diff changeset
    17
wdirrev = 0x7fffffff
1a5211f2f87f node: define experimental identifiers for working directory
Yuya Nishihara <yuya@tcha.org>
parents: 10263
diff changeset
    18
wdirid = "\xff" * 20
1a5211f2f87f node: define experimental identifiers for working directory
Yuya Nishihara <yuya@tcha.org>
parents: 10263
diff changeset
    19
4995
e45fc5d03798 manifest: speed up creation of the manifestdict
Matt Mackall <mpm@selenic.com>
parents: 3877
diff changeset
    20
# This ugly style has a noticeable effect in manifest parsing
e45fc5d03798 manifest: speed up creation of the manifestdict
Matt Mackall <mpm@selenic.com>
parents: 3877
diff changeset
    21
hex = binascii.hexlify
e45fc5d03798 manifest: speed up creation of the manifestdict
Matt Mackall <mpm@selenic.com>
parents: 3877
diff changeset
    22
bin = binascii.unhexlify
1089
142b5d5ec9cc Break apart hg.py
mpm@selenic.com
parents:
diff changeset
    23
142b5d5ec9cc Break apart hg.py
mpm@selenic.com
parents:
diff changeset
    24
def short(node):
142b5d5ec9cc Break apart hg.py
mpm@selenic.com
parents:
diff changeset
    25
    return hex(node[:6])