/**
* Returns a {@code CompactId} constructed from the ID's external format contained in the
* specified message buffer.
*
* @param buf a message buffer containing the external format of a {@code CompactId}
* @return a {@code CompactId} constructed from the external format in the given message buffer
* @throws IllegalArgumentException if the external format contained in the message buffer is
* malformed or unsupported
*/
public static CompactId getCompactId(MessageBuffer buf) {
int bufSize = buf.limit() - buf.position();
if (bufSize == 0) {
throw new IllegalArgumentException("empty buffer");
}
byte lengthByte = buf.getByte();
int size = getExternalFormByteCount(lengthByte);
if (bufSize < size) {
throw new IllegalArgumentException("buffer size insufficient");
}
byte[] externalForm = new byte[size];
externalForm[0] = lengthByte;
for (int i = 1; i < size; i++) {
externalForm[i] = buf.getByte();
}
return CompactId.fromExternalForm(externalForm);
}
