Updated DB_Helper by adding firebase methods.

venv/Lib/site-packages/gcloud/streaming/buffered_stream.py

@@ -0,0 +1,79 @@
+"""Small helper class to provide a small slice of a stream.
+
+This class reads ahead to detect if we are at the end of the stream.
+"""
+
+
+class BufferedStream(object):
+    """Buffers a stream, reading ahead to determine if we're at the end.
+
+    :type stream:  readable file-like object
+    :param stream:  the stream to be buffered
+
+    :type start: integer
+    :param start: the starting point in the stream
+
+    :type size: integer
+    :param size:  the size of the buffer
+    """
+    def __init__(self, stream, start, size):
+        self._stream = stream
+        self._start_pos = start
+        self._buffer_pos = 0
+        self._buffered_data = self._stream.read(size)
+        self._stream_at_end = len(self._buffered_data) < size
+        self._end_pos = self._start_pos + len(self._buffered_data)
+
+    def __repr__(self):
+        return ('Buffered stream %s from position %s-%s with %s '
+                'bytes remaining' % (self._stream, self._start_pos,
+                                     self._end_pos, self._bytes_remaining))
+
+    def __len__(self):
+        return len(self._buffered_data)
+
+    @property
+    def stream_exhausted(self):
+        """Does the stream have bytes remaining beyond the buffer
+
+        :rtype: boolean
+        """
+        return self._stream_at_end
+
+    @property
+    def stream_end_position(self):
+        """Point to which stream was read into the buffer
+
+        :rtype: integer
+        """
+        return self._end_pos
+
+    @property
+    def _bytes_remaining(self):
+        """Bytes remaining to be read from the buffer
+
+        :rtype: integer
+        """
+        return len(self._buffered_data) - self._buffer_pos
+
+    def read(self, size=None):
+        """Read bytes from the buffer.
+
+        :type size: integer or None
+        :param size: How many bytes to read (defaults to all remaining bytes).
+        """
+        if size is None or size < 0:
+            raise ValueError(
+                'Illegal read of size %s requested on BufferedStream. '
+                'Wrapped stream %s is at position %s-%s, '
+                '%s bytes remaining.' %
+                (size, self._stream, self._start_pos, self._end_pos,
+                 self._bytes_remaining))
+
+        if not self._bytes_remaining:
+            return b''
+
+        size = min(size, self._bytes_remaining)
+        data = self._buffered_data[self._buffer_pos:self._buffer_pos + size]
+        self._buffer_pos += size
+        return data