Home | History | Annotate | Download | only in system
      1 # Copyright (C) 2010 Google Inc. All rights reserved.
      2 #
      3 # Redistribution and use in source and binary forms, with or without
      4 # modification, are permitted provided that the following conditions are
      5 # met:
      6 #
      7 #     * Redistributions of source code must retain the above copyright
      8 # notice, this list of conditions and the following disclaimer.
      9 #     * Redistributions in binary form must reproduce the above
     10 # copyright notice, this list of conditions and the following disclaimer
     11 # in the documentation and/or other materials provided with the
     12 # distribution.
     13 #     * Neither the name of Google Inc. nor the names of its
     14 # contributors may be used to endorse or promote products derived from
     15 # this software without specific prior written permission.
     16 #
     17 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     18 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     19 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     20 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     21 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     22 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     23 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     24 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     25 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     26 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     27 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     28 
     29 """generic routines to convert platform-specific paths to URIs."""
     30 from __future__ import with_statement
     31 
     32 import atexit
     33 import subprocess
     34 import sys
     35 import threading
     36 import urllib
     37 
     38 
     39 def abspath_to_uri(path, platform=None):
     40     """Converts a platform-specific absolute path to a file: URL."""
     41     if platform is None:
     42         platform = sys.platform
     43     return "file:" + _escape(_convert_path(path, platform))
     44 
     45 
     46 def cygpath(path):
     47     """Converts an absolute cygwin path to an absolute Windows path."""
     48     return _CygPath.convert_using_singleton(path)
     49 
     50 
     51 # Note that this object is not threadsafe and must only be called
     52 # from multiple threads under protection of a lock (as is done in cygpath())
     53 class _CygPath(object):
     54     """Manages a long-running 'cygpath' process for file conversion."""
     55     _lock = None
     56     _singleton = None
     57 
     58     @staticmethod
     59     def stop_cygpath_subprocess():
     60         if not _CygPath._lock:
     61             return
     62 
     63         with _CygPath._lock:
     64             if _CygPath._singleton:
     65                 _CygPath._singleton.stop()
     66 
     67     @staticmethod
     68     def convert_using_singleton(path):
     69         if not _CygPath._lock:
     70             _CygPath._lock = threading.Lock()
     71 
     72         with _CygPath._lock:
     73             if not _CygPath._singleton:
     74                 _CygPath._singleton = _CygPath()
     75                 # Make sure the cygpath subprocess always gets shutdown cleanly.
     76                 atexit.register(_CygPath.stop_cygpath_subprocess)
     77 
     78             return _CygPath._singleton.convert(path)
     79 
     80     def __init__(self):
     81         self._child_process = None
     82 
     83     def start(self):
     84         assert(self._child_process is None)
     85         args = ['cygpath', '-f', '-', '-wa']
     86         self._child_process = subprocess.Popen(args,
     87                                                stdin=subprocess.PIPE,
     88                                                stdout=subprocess.PIPE)
     89 
     90     def is_running(self):
     91         if not self._child_process:
     92             return False
     93         return self._child_process.returncode is None
     94 
     95     def stop(self):
     96         if self._child_process:
     97             self._child_process.stdin.close()
     98             self._child_process.wait()
     99         self._child_process = None
    100 
    101     def convert(self, path):
    102         if not self.is_running():
    103             self.start()
    104         self._child_process.stdin.write("%s\r\n" % path)
    105         self._child_process.stdin.flush()
    106         windows_path = self._child_process.stdout.readline().rstrip()
    107         # Some versions of cygpath use lowercase drive letters while others
    108         # use uppercase. We always convert to uppercase for consistency.
    109         windows_path = '%s%s' % (windows_path[0].upper(), windows_path[1:])
    110         return windows_path
    111 
    112 
    113 def _escape(path):
    114     """Handle any characters in the path that should be escaped."""
    115     # FIXME: web browsers don't appear to blindly quote every character
    116     # when converting filenames to files. Instead of using urllib's default
    117     # rules, we allow a small list of other characters through un-escaped.
    118     # It's unclear if this is the best possible solution.
    119     return urllib.quote(path, safe='/+:')
    120 
    121 
    122 def _convert_path(path, platform):
    123     """Handles any os-specific path separators, mappings, etc."""
    124     if platform == 'win32':
    125         return _winpath_to_uri(path)
    126     if platform == 'cygwin':
    127         return _winpath_to_uri(cygpath(path))
    128     return _unixypath_to_uri(path)
    129 
    130 
    131 def _winpath_to_uri(path):
    132     """Converts a window absolute path to a file: URL."""
    133     return "///" + path.replace("\\", "/")
    134 
    135 
    136 def _unixypath_to_uri(path):
    137     """Converts a unix-style path to a file: URL."""
    138     return "//" + path
    139