view hgweb.cgi @ 41978:a56487081109

store: don't read the whole fncache in memory

In large repositories with lot of files, the fncache grows more than 100 MB and
reading that whole thing into memory slows things down. Let's not read the whole
thing into memory.

This patch changes fncache loading code to read 1 MB at once. Loading 1 MB at
once saves ~1 sec on perffncacheload for our internal repository. I tried
various values such as 0.5 MB, 5 MB, 10 MB but best results were produced using
1 MB as the chunksize.

On a narrow clone with fncache around 40 MB, this patch saves ~0.04 seconds on
average on perffncacheload.

To test the code, I have coded an extension in test-fncache.t which set
chunksize to 1 byte, and the test passes with that.

Differential Revision: https://phab.mercurial-scm.org/D5296

#!/usr/bin/env python
#
# An example hgweb CGI script, edit as necessary
# See also https://mercurial-scm.org/wiki/PublishingRepositories

# Path to repo or hgweb config to serve (see 'hg help hgweb')
config = "/path/to/repo/or/config"

# Uncomment and adjust if Mercurial is not installed system-wide
# (consult "installed modules" path from 'hg debuginstall'):
#import sys; sys.path.insert(0, "/path/to/python/lib")

# Uncomment to send python tracebacks to the browser if an error occurs:
#import cgitb; cgitb.enable()

from mercurial import demandimport; demandimport.enable()
from mercurial.hgweb import hgweb, wsgicgi
application = hgweb(config)
wsgicgi.launch(application)