changelog: add class to represent parsed changelog revisions
Currently, changelog entries are parsed into their respective
components at read time. Many operations are only interested
in a subset of fields of a changelog entry. The parsing and
storing of all the fields adds avoidable overhead.
This patch introduces the "changelogrevision" class. It takes
changelog raw text and exposes the parsed results as attributes.
The code for parsing changelog entries has been moved into its
construction function. changelog.read() has been modified to use
the new class internally while maintaining its existing API.
Future patches will make revision parsing lazy.
We implement the construction function of the new class with
__new__ instead of __init__ so we can use a named tuple to
represent the empty revision. This saves overhead and complexity
of coercing later versions of this class to represent an empty
instance.
While we are here, we add a method on changelog to obtain an
instance of the new type.
The overhead of constructing the new class regresses performance
of revsets accessing this data:
author(mpm)
0.896565
0.929984
desc(bug)
0.887169
0.935642 105%
date(2015)
0.878797
0.908094
extra(rebase_source)
0.865446
0.922624 106%
author(mpm) or author(greg)
1.801832
1.902112 105%
author(mpm) or desc(bug)
1.812438
1.860977
date(2015) or branch(default)
0.968276
1.005824
author(mpm) or desc(bug) or date(2015) or extra(rebase_source)
3.656193
3.743381
Once lazy parsing is implemented, these revsets will all be faster
than before. There is no performance change on revsets that do not
access this data. There /could/ be a performance regression on
operations that perform several changelog reads. However, I can't
think of anything outside of revsets and `hg log` (basically the
same as a revset) that would be impacted.
A dummy certificate that will make OS X 10.6+ Python use the system CA
certificate store:
-----BEGIN CERTIFICATE-----
MIIBIzCBzgIJANjmj39sb3FmMA0GCSqGSIb3DQEBBQUAMBkxFzAVBgNVBAMTDmhn
LmV4YW1wbGUuY29tMB4XDTE0MDgzMDA4NDU1OVoXDTE0MDgyOTA4NDU1OVowGTEX
MBUGA1UEAxMOaGcuZXhhbXBsZS5jb20wXDANBgkqhkiG9w0BAQEFAANLADBIAkEA
mh/ZySGlcq0ALNLmA1gZqt61HruywPrRk6WyrLJRgt+X7OP9FFlEfl2tzHfzqvmK
CtSQoPINWOdAJMekBYFgKQIDAQABMA0GCSqGSIb3DQEBBQUAA0EAF9h49LkSqJ6a
IlpogZuUHtihXeKZBsiktVIDlDccYsNy0RSh9XxUfhk+XMLw8jBlYvcltSXdJ7We
aKdQRekuMQ==
-----END CERTIFICATE-----
This certificate was generated to be syntactically valid but never be usable;
it expired before it became valid.
Created as:
$ cat > cn.conf << EOT
> [req]
> distinguished_name = req_distinguished_name
> [req_distinguished_name]
> commonName = Common Name
> commonName_default = no.example.com
> EOT
$ openssl req -nodes -new -x509 -keyout /dev/null \
> -out dummycert.pem -days -1 -config cn.conf -subj '/CN=hg.example.com'
To verify the content of this certificate:
$ openssl x509 -in dummycert.pem -noout -text
Certificate:
Data:
Version: 1 (0x0)
Serial Number: 15629337334278746470 (0xd8e68f7f6c6f7166)
Signature Algorithm: sha1WithRSAEncryption
Issuer: CN=hg.example.com
Validity
Not Before: Aug 30 08:45:59 2014 GMT
Not After : Aug 29 08:45:59 2014 GMT
Subject: CN=hg.example.com
Subject Public Key Info:
Public Key Algorithm: rsaEncryption
Public-Key: (512 bit)
Modulus:
00:9a:1f:d9:c9:21:a5:72:ad:00:2c:d2:e6:03:58:
19:aa:de:b5:1e:bb:b2:c0:fa:d1:93:a5:b2:ac:b2:
51:82:df:97:ec:e3:fd:14:59:44:7e:5d:ad:cc:77:
f3:aa:f9:8a:0a:d4:90:a0:f2:0d:58:e7:40:24:c7:
a4:05:81:60:29
Exponent: 65537 (0x10001)
Signature Algorithm: sha1WithRSAEncryption
17:d8:78:f4:b9:12:a8:9e:9a:22:5a:68:81:9b:94:1e:d8:a1:
5d:e2:99:06:c8:a4:b5:52:03:94:37:1c:62:c3:72:d1:14:a1:
f5:7c:54:7e:19:3e:5c:c2:f0:f2:30:65:62:f7:25:b5:25:dd:
27:b5:9e:68:a7:50:45:e9:2e:31