select
Finds the first string in options that is a prefix of this buffer, consumes it from this buffer, and returns its index. If no byte string in options is a prefix of this buffer this returns -1 and no bytes are consumed.
This can be used as an alternative to readByteString or even readUtf8 if the set of expected values is known in advance.
Options FIELDS = Options.of(
ByteString.encodeUtf8("depth="),
ByteString.encodeUtf8("height="),
ByteString.encodeUtf8("width="));
Buffer buffer = new Buffer()
.writeUtf8("width=640\n")
.writeUtf8("height=480\n");
assertEquals(2, buffer.select(FIELDS));
assertEquals(640, buffer.readDecimalLong());
assertEquals('\n', buffer.readByte());
assertEquals(1, buffer.select(FIELDS));
assertEquals(480, buffer.readDecimalLong());
assertEquals('\n', buffer.readByte());