getinfokeys method

git-svn-id: http://pyfilesystem.googlecode.com/svn/trunk@881 67cdc799-7952-0410-af00-57a81ceafa0f

3 files changed, 48 insertions, 4 deletions

diff --git a/fs/base.py b/fs/base.py
index 8e2686e..fed68fb 100644
--- a/fs/base.py
+++ b/fs/base.py
@@ -740,6 +740,22 @@ class FS(object):
         """
         raise UnsupportedError("get resource info")
 
+    def getinfokeys(self, path, *keys):
+        """Get specified keys from info dict, as returned from `getinfo`. The returned dictionary may
+        not contain all the keys that were asked for, if they aren't available.
+
+        This method allows a filesystem to potentially provide a faster way of retrieving these info values if you
+        are only interested in a subset of them.
+
+        :param path: a path to retrieve information for
+        :param keys: the info keys you would like to retrieve
+
+        :rtype: dict
+
+        """
+        info = self.getinfo(path)
+        return {k: info[k] for k in keys if k in info}
+
     def desc(self, path):
         """Returns short descriptive text regarding a path. Intended mainly as
         a debugging aid.
@@ -760,8 +776,13 @@ class FS(object):
         """Returns the contents of a file as a string.
 
         :param path: A path of file to read
+        :param mode: Mode to open file with (should be 'rb' for binary or 't' for text)
+        :param encoding: Encoding to use when reading contents in text mode
+        :param errors: Unicode errors parameter if text mode is use
+        :param newline: Newlines parameter for text mode decoding
         :rtype: str
         :returns: file contents
+
         """
         if 'r' not in mode:
             raise ValueError("mode must contain 'r' to be readable")
diff --git a/fs/opener.py b/fs/opener.py
index 49fef9b..54cebe3 100644
--- a/fs/opener.py
+++ b/fs/opener.py
@@ -271,7 +271,7 @@ class OpenerRegistry(object):
         file_object.fs = fs
         return file_object
 
-    def getcontents(self, fs_url, node='rb', encoding=None, errors=None, newline=None):
+    def getcontents(self, fs_url, mode='rb', encoding=None, errors=None, newline=None):
         """Gets the contents from a given FS url (if it references a file)
 
         :param fs_url: a FS URL e.g. ftp://ftp.mozilla.org/README
diff --git a/fs/osfs/__init__.py b/fs/osfs/__init__.py
index 47ce406..5785f0e 100644
--- a/fs/osfs/__init__.py
+++ b/fs/osfs/__init__.py
@@ -343,17 +343,40 @@ class OSFS(OSFSXAttrMixin, OSFSWatchMixin, FS):
         info = dict((k, getattr(stats, k)) for k in dir(stats) if k.startswith('st_'))
         info['size'] = info['st_size']
         #  TODO: this doesn't actually mean 'creation time' on unix
+        fromtimestamp = datetime.datetime.fromtimestamp
         ct = info.get('st_ctime', None)
         if ct is not None:
-            info['created_time'] = datetime.datetime.fromtimestamp(ct)
+            info['created_time'] = fromtimestamp(ct)
         at = info.get('st_atime', None)
         if at is not None:
-            info['accessed_time'] = datetime.datetime.fromtimestamp(at)
+            info['accessed_time'] = fromtimestamp(at)
         mt = info.get('st_mtime', None)
         if mt is not None:
-            info['modified_time'] = datetime.datetime.fromtimestamp(mt)
+            info['modified_time'] = fromtimestamp(mt)
         return info
 
     @convert_os_errors
+    def getinfokeys(self, path, *keys):
+        info = {}
+        stats = self._stat(path)
+        fromtimestamp = datetime.datetime.fromtimestamp
+        for key in keys:
+            try:
+                if key == 'size':
+                    info[key] = stats.st_size
+                elif key == 'modified_time':
+                    info[key] = fromtimestamp(stats.st_mtime)
+                elif key == 'created_time':
+                    info[key] = fromtimestamp(stats.st_ctime)
+                elif key == 'accessed_time':
+                    info[key] = fromtimestamp(stats.st_atime)
+                else:
+                    info[key] = getattr(stats, key)
+            except AttributeError:
+                continue
+        return info
+
+
+    @convert_os_errors
     def getsize(self, path):
         return self._stat(path).st_size