def _readline(sock, buf): """Read line of text from the socket. Read a line of text (delimited by "\r\n") from the socket, and return that line along with any trailing characters read from the socket. Args: sock: Socket object, should be connected. buf: String, zero or more characters, returned from an earlier call to _readline or _readvalue (pass an empty string on the first call). Returns: A tuple of (buf, line) where line is the full line read from the socket (minus the "\r\n" characters) and buf is any trailing characters read after the "\r\n" was found (which may be an empty string). """ chunks = [] last_char = b'' while True: # We're reading in chunks, so "\r\n" could appear in one chunk, # or across the boundary of two chunks, so we check for both # cases. # This case must appear first, since the buffer could have # later \r\n characters in it and we want to get the first \r\n. if last_char == b'\r' and buf[0:1] == b'\n': # Strip the last character from the last chunk. chunks[-1] = chunks[-1][:-1] return buf[1:], b''.join(chunks) elif buf.find(b'\r\n') != -1: before, sep, after = buf.partition(b"\r\n") chunks.append(before) return after, b''.join(chunks) if buf: chunks.append(buf) last_char = buf[-1:] buf = _recv(sock, RECV_SIZE) if not buf: raise MemcacheUnexpectedCloseError()
def _readvalue(sock, buf, size): """Read specified amount of bytes from the socket. Read size bytes, followed by the "\r\n" characters, from the socket, and return those bytes and any trailing bytes read after the "\r\n". Args: sock: Socket object, should be connected. buf: String, zero or more characters, returned from an earlier call to _readline or _readvalue (pass an empty string on the first call). size: Integer, number of bytes to read from the socket. Returns: A tuple of (buf, value) where value is the bytes read from the socket (there will be exactly size bytes) and buf is trailing characters read after the "\r\n" following the bytes (but not including the \r\n). """ chunks = [] rlen = size + 2 while rlen - len(buf) > 0: if buf: rlen -= len(buf) chunks.append(buf) buf = _recv(sock, RECV_SIZE) if not buf: raise MemcacheUnexpectedCloseError() # Now we need to remove the \r\n from the end. There are two cases we care # about: the \r\n is all in the last buffer, or only the \n is in the last # buffer, and we need to remove the \r from the penultimate buffer. if rlen == 1: # replace the last chunk with the same string minus the last character, # which is always '\r' in this case. chunks[-1] = chunks[-1][:-1] else: # Just remove the "\r\n" from the latest chunk chunks.append(buf[:rlen - 2]) return buf[rlen:], b''.join(chunks)