def _init_value(self, key):
encoded = key.encode('<STR_LIT:utf-8>')<EOL>padded = encoded + (b'<STR_LIT:U+0020>' * (<NUM_LIT:8> - (len(encoded) + <NUM_LIT:4>) % <NUM_LIT:8>))<EOL>value = struct.pack('<STR_LIT>'.format(len(padded)).encode(), len(encoded), padded, <NUM_LIT:0.0>)<EOL>while self._used + len(value) > self._capacity:<EOL><INDENT>self._capacity *= <NUM_LIT:2><EOL>self._f.truncate(self._capacity)<EOL>self._m = mmap.mmap(self._f.fileno(), self._capacity)<EOL><DEDENT>self._m[self._used:self._used + len(value)] = value<EOL>self._used += len(value)<EOL>_pack_integer(self._m, <NUM_LIT:0>, self._used)<EOL>self._positions[key] = self._used - <NUM_LIT:8><EOL>
Initialize a value. Lock must be held by caller.