Bug 1168607 - Add a read() method to File; r=glandium

Passing raw file handles around is a bit dangerous because it could lead
to leaking file descriptors. Add a read() method that handles the simple
case of obtaining the full contents of a File instance.

This should ideally be a method on BaseFile. But this would require
extra work and isn't needed. So we've deferred it until bug 1170329.

--HG--
extra : commitid : 82qw76XmpjC
extra : rebase_source : 422b16c5a3b1577f080097925aeaeb560aa3e798

python/mozbuild/mozpack/files.py

@@ -189,6 +189,9 @@ class BaseFile(object):
         assert self.path is not None
         return open(self.path, 'rb')
 
+    def read(self):
+        raise NotImplementedError('BaseFile.read() not implemented. Bug 1170329.')
+
     @property
     def mode(self):
         '''
@@ -227,6 +230,12 @@ class File(BaseFile):
         # - leave away sticky bit, setuid, setgid
         return ret
 
+    def read(self):
+        '''Return the contents of the file.'''
+        with open(self.path, 'rb') as fh:
+            return fh.read()
+
+
 class ExecutableFile(File):
     '''
     File class for executable and library files on OS/2, OS/X and ELF systems.