Yeah buddy

lib/nntp/tiny/buffer.py

@@ -5,35 +5,35 @@ class BufferOverflow(Exception):
         super().__init__("Buffer overflow")
 
 class LineBuffer():
-    __slots__ = 'buf', 'size', 'offset', 'count', 'eof', 'done',
+    __slots__ = 'buf', 'size', 'offset_i', 'offset_o', 'eof', 'done',
 
     BUFFER_SIZE = 4096
 
     def __init__(self, size: int=BUFFER_SIZE):
-        self.buf:    bytearray = bytearray(size)
-        self.size:   int = size
-        self.offset: int = 0
-        self.count:  int = 0
-        self.eof:    bool = False
-        self.done:   bool = False
+        self.buf:      bytearray = bytearray(size)
+        self.size:     int = size
+        self.offset_i: int = 0
+        self.offset_o: int = 0
+        self.eof:      bool = False
+        self.done:     bool = False
 
     def _shift(self):
-        count = self.size - self.offset
+        count = self.offset_i - self.offset_o
 
-        self.buf[0:count] = self.buf[self.offset:self.count]
 
-        self.offset = 0
-        self.count  = count
+        self.buf[0:count] = self.buf[self.offset_o:self.offset_i]
+
+        self.offset_i = count
+        self.offset_o = 0
 
     def _is_full(self):
-        return self.count == self.size
+        return self.offset_i >= self.size
 
     def _fill(self, sock: socket.socket):
         if self.eof:
             return
 
-        readlen = self.size - self.count
-        data    = sock.recv(readlen)
+        data = sock.recv(self.size - self.offset_i)
 
         if data == b'':
             self.eof = True
@@ -41,28 +41,40 @@ class LineBuffer():
 
         readlen = len(data)
 
-        self.buf[self.offset:self.offset+readlen] = data
 
-        self.count += readlen
+        self.buf[self.offset_i:self.size] = data
 
-    def _flush(self, end: int):
-        ret = self.buf[self.offset:end+1]
+        self.offset_i += readlen
 
-        self.offset = end + 1
+    def _drain(self, end=None):
+        if end is None:
+            end = self.offset_i + 1
+
+        ret = self.buf[self.offset_o:end+1]
+
+        self.offset_o = end + 1
 
         return str(ret, 'ascii')
 
     def readline(self, sock: socket.socket) -> str:
+        if self.done:
+            return ''
+        
         while True:
-            index = self.buf.find(b'\n', self.offset, self.count)
+            index = self.buf.find(b'\n', self.offset_o, self.offset_i)
+
 
             if index < 0:
                 if self._is_full():
-                    if self.offset == 0:
+                    if self.offset_o == 0:
                         raise BufferOverflow()
-                    else:
-                        self._shift()
+                    
+                    self._shift()
+                elif self.eof:
+                    self.done = True
+
+                    return self._drain()
                 else:
                     self._fill(sock)
             else:
-                return self._flush(index)
+                return self._drain(index)