utils: remove BackwardsReadablestream

utils.py

@@ -152,63 +152,6 @@ def is_zstd(data):
     return True
 
 
-class BackwardsReadableStream:
-    def __init__(self, stream):
-        self.stream = stream
-        self.buffer = bytearray()
-        self.position = 0
-
-    def read(self, size=-1):
-        data = b''
-        if size == -1:
-            # read all remaining data in stream
-            data = self.stream.read()
-        else:
-            not_read = (self.position + size) - len(self.buffer)
-            if not_read > 0:
-                # read up to size bytes from stream
-                data = self.stream.read(not_read)
-            else:
-                data = self.buffer[self.position:self.position+size+1]
-
-        old_position = self.position
-        new_position = self.position + len(data)
-        self.buffer.extend(data)
-        self.position = new_position
-        return self.buffer[old_position:new_position+1]
-
-    def seek(self, offset, whence=0):
-        if whence == 0:
-            # seek from beginning of buffer
-            self.position = offset
-        elif whence == 1:
-            # seek from current position
-            self.position += offset
-        elif whence == 2:
-            # seek from end of buffer
-            self.position = len(self.buffer) + offset
-        else:
-            raise ValueError("Invalid whence value")
-
-        # adjust position to be within buffer bounds
-        self.position = max(0, min(self.position, len(self.buffer)))
-
-    def tell(self):
-        return self.position
-
-    def readable(self):
-        return True
-
-    def seekable(self):
-        return True
-
-    def __enter__(self):
-        return self
-
-    def __exit__(self, exc_type, exc_value, traceback):
-        self.stream.__exit__(exc_type, exc_value, traceback)
-
-
 def decompress_if_zstd(stream):
     """
     Given a byte stream, returns either the original stream or the decompressed stream