branchcache: skip entries that are topological heads in the on disk file
In the majority of cases, topological heads are also branch heads. We have
efficient way to get the topological heads and efficient way to retrieve
their branch information. So there is little value in putting them in the branch
cache file explicitly. On the contrary, writing them explicitly tend to create
very large cache file that are inefficient to read and update.
So the branch cache v3 format is no longer including them. This changeset focus
on the format aspect and have no focus on the performance aspect. We will cover
that later.
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