Use "svn cat" in tools/submit_try

tools/svn.py

 '''
 Copyright 2011 Google Inc.
 
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file.
 '''
 
 import fnmatch
 import os
 import re
 import subprocess
 
 PROPERTY_MIMETYPE = 'svn:mime-type'
 
 # Status types for GetFilesWithStatus()
 STATUS_ADDED                 = 0x01
 STATUS_DELETED               = 0x02
 STATUS_MODIFIED              = 0x04
 STATUS_NOT_UNDER_SVN_CONTROL = 0x08
 
+
+if os.name == 'nt':
+  SVN = 'svn.bat'

[epoger, 2013/03/14 17:48:32]

I think this is fine... although I think it worked before anyway, since Windows
will run "svn.bat" if you call "svn", anyway.

[borenet, 2013/03/14 18:25:18]

Actually, my experience with this is that that is the case when you run things
by hand, but shelling out from a python script is somehow different and you get
errors if you don't provide the extension.

+else:
+  SVN = 'svn'
+
+
 class Svn:
 
     def __init__(self, directory):
         """Set up to manipulate SVN control within the given directory.
 
         @param directory
         """
         self._directory = directory
 
     def _RunCommand(self, args):
@@ skipping 12 matching lines @@
         return stdout
 
     def Checkout(self, url, path):
         """Check out a working copy from a repository.
         Returns stdout as a single string.
 
         @param url URL from which to check out the working copy
         @param path path (within self._directory) where the local copy will be
         written
         """
-        return self._RunCommand(['svn', 'checkout', url, path])
+        return self._RunCommand([SVN, 'checkout', url, path])
 
     def ListSubdirs(self, url):
         """Returns a list of all subdirectories (not files) within a given SVN
         url.
 
         @param url remote directory to list subdirectories of
         """
         subdirs = []
-        filenames = self._RunCommand(['svn', 'ls', url]).split('\n')
+        filenames = self._RunCommand([SVN, 'ls', url]).split('\n')
         for filename in filenames:
             if filename.endswith('/'):
                 subdirs.append(filename.strip('/'))
         return subdirs
 
     def GetNewFiles(self):
         """Return a list of files which are in this directory but NOT under
         SVN control.
         """
         return self.GetFilesWithStatus(STATUS_NOT_UNDER_SVN_CONTROL)
@@ skipping 13 matching lines @@
         status_types_string = ''
         if status & STATUS_ADDED:
             status_types_string += 'A'
         if status & STATUS_DELETED:
             status_types_string += 'D'
         if status & STATUS_MODIFIED:
             status_types_string += 'M'
         if status & STATUS_NOT_UNDER_SVN_CONTROL:
             status_types_string += '\?'
         status_regex_string = '^[%s].....\s+(.+)$' % status_types_string
-        stdout = self._RunCommand(['svn', 'status'])
+        stdout = self._RunCommand([SVN, 'status'])
         status_regex = re.compile(status_regex_string, re.MULTILINE)
         files = status_regex.findall(stdout)
         return files
 
     def AddFiles(self, filenames):
         """Adds these files to SVN control.
 
         @param filenames files to add to SVN control
         """
-        self._RunCommand(['svn', 'add'] + filenames)
+        self._RunCommand([SVN, 'add'] + filenames)
 
     def SetProperty(self, filenames, property_name, property_value):
         """Sets a svn property for these files.
 
         @param filenames files to set property on
         @param property_name property_name to set for each file
         @param property_value what to set the property_name to
         """
         if filenames:
             self._RunCommand(
-                ['svn', 'propset', property_name, property_value] + filenames)
+                [SVN, 'propset', property_name, property_value] + filenames)
 
     def SetPropertyByFilenamePattern(self, filename_pattern,
                                      property_name, property_value):
         """Sets a svn property for all files matching filename_pattern.
 
         @param filename_pattern set the property for all files whose names match
                this Unix-style filename pattern (e.g., '*.jpg')
         @param property_name property_name to set for each file
         @param property_value what to set the property_name to
         """
         all_files = os.listdir(self._directory)
         matching_files = sorted(fnmatch.filter(all_files, filename_pattern))
         self.SetProperty(matching_files, property_name, property_value)
 
     def ExportBaseVersionOfFile(self, file_within_repo, dest_path):
         """Retrieves a copy of the base version (what you would get if you ran
         'svn revert') of a file within the repository.
 
         @param file_within_repo path to the file within the repo whose base
                version you wish to obtain
         @param dest_path destination to which to write the base content
         """
-        self._RunCommand(['svn', 'export', '--revision', 'BASE',
+        self._RunCommand([SVN, 'export', '--revision', 'BASE',
                           file_within_repo, dest_path])
+
+    @staticmethod
+    def Cat(svn_url):

[epoger, 2013/03/14 17:48:32]

Maybe move this outside of the Svn class declaration, and then the caller can
just say "svn.Cat()" instead of "svn.Svn.Cat()"?

Given that this operates outside the context of an Svn object (which is tied to
a particular directory on local disk), I think that would be clearer.

But I don't feel particularly strongly about this.

[borenet, 2013/03/14 18:25:18]

Done.

+        """Returns the contents of the file at the given svn_url. 
+
+        @param svn_url URL of the file to read
+        """
+        proc = subprocess.Popen([SVN, 'cat', svn_url],
+                                stdout=subprocess.PIPE,
+                                stderr=subprocess.STDOUT)
+        exitcode = proc.wait()
+        if not exitcode == 0:
+          raise Exception('Could not retrieve %s. Verify that the URL is valid '
+                          'and check your connection.' % svn_url)
+        return proc.communicate()[0]