view mercurial/dummycert.pem @ 27895:2d6a89e79b48

scmutil: support background file closing

Closing files that have been appended to is relatively slow on
Windows/NTFS. This makes several Mercurial operations slower on
Windows.

The workaround to this issue is conceptually simple: use multiple
threads for I/O. Unfortunately, Python doesn't scale well to multiple
threads because of the GIL. And, refactoring our code to use threads
everywhere would be a huge undertaking. So, we decide to tackle this
problem by starting small: establishing a thread pool for closing
files.

This patch establishes a mechanism for closing file handles on separate
threads. The coordinator object is basically a queue of file handles to
operate on and a thread pool consuming from the queue.

When files are opened through the VFS layer, the caller can specify
that delay closing is allowed.

A proxy class for file handles has been added. We must use a proxy
because it isn't possible to modify __class__ on built-in types. This
adds some overhead. But as future patches will show, this overhead
is cancelled out by the benefit of closing file handles on background
threads.

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