hgweb.cgi

inotify: server: new data structure to keep track of changes.

== Rationale for the new structure ==

Current structure was a dictionary tree. One directory was tracked
as a dictionary:
 - keys: file/subdir name
 - values:
    - for a file, the status (a/r/m/...)
    - for a subdir, the directory representing the subdir

It allowed efficient lookups, no matter of the type of the terminal leaf:
    for part in path.split('/'): tree = tree[part]

However, there is no way to represent a directory and a file with the same name
because keys are conflicting in the dictionary. Concrete example:

Initial state:

root dir
 |- foo (file)
 |- bar (file)

# data state is: {'foo': 'n', 'bar': 'n'}

Remove foo:

root dir
 |- bar (file)

# Data becomes {'foo': 'r'} until next commit.

Add foo, as a directory, and foo/barbar file:

root dir
 |- bar (file)
 |-> foo (dir)
  |- barbar (file)

# New state should be represented as:
  {'foo': {'barbar': 'a'}, 'bar': 'n'}
  however, the key "foo" is already used and represents the old file.

The dirstate:
 D foo
 A foo/barbar
cannot be represented, hence the need for a new structure.

== The new structure ==

'directory' class. Represents one directory level.
* Notable attributes:
  Two dictionaries:
   - 'files' Maps filename -> status for the current dir.
   - 'dirs' Maps subdir's name -> directory object representing the subdir
* methods
  - walk(), formerly server.walk
  - lookup(), old server.lookup
  - dir(), old server.dir

This new class allows embedding all the tree walks/lookups in its own class,
instead of having everything mixed together in server.

Incidently, since files and directories are not stored in the same
dictionaries, we are solving the previous key conflict problem.

The small drawback is that lookup operation is a bit more complex:
for a path a/b/c/d/e we have to check twice the leaf, if e is a directory or a
file.

#!/usr/bin/env python
#
# An example CGI script to use hgweb, edit as necessary

# adjust python path if not a system-wide install:
#import sys
#sys.path.insert(0, "/path/to/python/lib")

# enable importing on demand to reduce startup time
from mercurial import demandimport; demandimport.enable()

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

# If you'd like to serve pages with UTF-8 instead of your default
# locale charset, you can do so by uncommenting the following lines.
# Note that this will cause your .hgrc files to be interpreted in
# UTF-8 and all your repo files to be displayed using UTF-8.
#
#import os
#os.environ["HGENCODING"] = "UTF-8"

from mercurial.hgweb.hgweb_mod import hgweb
import mercurial.hgweb.wsgicgi as wsgicgi

application = hgweb("/path/to/repo", "repository name")
wsgicgi.launch(application)