emit
Writes complete segments to the underlying sink, if one exists. Like flush, but weaker. Use this to limit the memory held in the buffer to a single segment. Typically application code will not need to call this: it is only necessary when application code writes directly to this sink's buffer.
BufferedSink b0 = new Buffer();
BufferedSink b1 = Okio.buffer(b0);
BufferedSink b2 = Okio.buffer(b1);
b2.buffer().write(new byte[20_000]);
assertEquals(20_000, b2.buffer().size());
assertEquals( 0, b1.buffer().size());
assertEquals( 0, b0.buffer().size());
b2.emitCompleteSegments();
assertEquals( 3_616, b2.buffer().size());
assertEquals( 0, b1.buffer().size());
assertEquals(16_384, b0.buffer().size()); // This example assumes 8192 byte segments.