/** Utility method for testing writables. */
public static Writable testWritable(Writable before, Configuration conf) throws Exception {
DataOutputBuffer dob = new DataOutputBuffer();
before.write(dob);
DataInputBuffer dib = new DataInputBuffer();
dib.reset(dob.getData(), dob.getLength());
Writable after = (Writable) ReflectionUtils.newInstance(before.getClass(), conf);
after.readFields(dib);
assertEquals(before, after);
return after;
}
/** Used by child copy constructors. */
protected synchronized void copy(Writable other) {
if (other != null) {
try {
DataOutputBuffer out = new DataOutputBuffer();
other.write(out);
DataInputBuffer in = new DataInputBuffer();
in.reset(out.getData(), out.getLength());
readFields(in);
} catch (IOException e) {
throw new IllegalArgumentException("map cannot be copied: " + e.getMessage());
}
} else {
throw new IllegalArgumentException("source map cannot be null");
}
}
/** Move the data from the output buffer to the input buffer. */
void moveData() {
inBuffer.reset(outBuffer.getData(), outBuffer.getLength());
}