moved dropbox library

resources/lib/dropbox/util.py

@@ -0,0 +1,53 @@
+import os
+
+class AnalyzeFileObjBug(Exception):
+    msg = ("\n"
+           "Expected file object to have %d bytes, instead we read %d bytes.\n"
+           "File size detection may have failed (see dropbox.util.AnalyzeFileObj)\n")
+    def __init__(self, expected, actual):
+        self.expected = expected
+        self.actual = actual
+
+    def __str__(self):
+        return self.msg % (self.expected, self.actual)
+
+def analyze_file_obj(obj):
+    """ Get the size and contents of a file-like object.
+        Returns:  (size, raw_data)
+                  size: The amount of data waiting to be read
+                  raw_data: If not None, the entire contents of the stream (as a string).
+                            None if the stream should be read() in chunks.
+    """
+    pos = 0
+    if hasattr(obj, 'tell'):
+        pos = obj.tell()
+
+    # Handle cStringIO and StringIO
+    if hasattr(obj, 'getvalue'):
+        # Why using getvalue() makes sense:
+        #   For StringIO, this string is pre-computed anyway by read().
+        #   For cStringIO, getvalue() is the only way
+        #     to determine the length without read()'ing the whole thing.
+        raw_data = obj.getvalue()
+        if pos == 0:
+            return (len(raw_data), raw_data)
+        else:
+            # We could return raw_data[pos:], but that could drastically
+            # increase memory usage. Better to read it block at a time.
+            size = max(0, len(raw_data) - pos)
+            return (size, None)
+
+    # Handle real files
+    if hasattr(obj, 'fileno'):
+        size = max(0, os.fstat(obj.fileno()).st_size - pos)
+        return (size, None)
+
+    # User-defined object with len()
+    if hasattr(obj, '__len__'):
+        size = max(0, len(obj) - pos)
+        return (size, None)
+
+    # We don't know what kind of stream this is.
+    # To determine the size, we must read the whole thing.
+    raw_data = obj.read()
+    return (len(raw_data), raw_data)