/**
* Since this coder uses elementCoders.get(index) and coders that are known to run in constant
* time, we defer the return value to that coder.
*/
@Override
public boolean isRegisterByteSizeObserverCheap(RawUnionValue union, Context context) {
int index = getIndexForEncoding(union);
@SuppressWarnings("unchecked")
Coder<Object> coder = (Coder<Object>) elementCoders.get(index);
return coder.isRegisterByteSizeObserverCheap(union.getValue(), context);
}
private int getIndexForEncoding(RawUnionValue union) {
if (union == null) {
throw new IllegalArgumentException("cannot encode a null tagged union");
}
int index = union.getUnionTag();
if (index < 0 || index >= elementCoders.size()) {
throw new IllegalArgumentException(
"union value index " + index + " not in range [0.." + (elementCoders.size() - 1) + "]");
}
return index;
}
/** Notifies ElementByteSizeObserver about the byte size of the encoded value using this coder. */
@Override
public void registerByteSizeObserver(
RawUnionValue union, ElementByteSizeObserver observer, Context context) throws Exception {
int index = getIndexForEncoding(union);
// Write out the union tag.
observer.update(VarInt.getLength(index));
// Write out the actual value.
@SuppressWarnings("unchecked")
Coder<Object> coder = (Coder<Object>) elementCoders.get(index);
coder.registerByteSizeObserver(union.getValue(), observer, context);
}
@SuppressWarnings("unchecked")
@Override
public void encode(RawUnionValue union, OutputStream outStream, Context context)
throws IOException, CoderException {
int index = getIndexForEncoding(union);
// Write out the union tag.
VarInt.encode(index, outStream);
// Write out the actual value.
Coder<Object> coder = (Coder<Object>) elementCoders.get(index);
coder.encode(union.getValue(), outStream, context);
}
