/** 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; }
/** * Optimization hook. Override this to make SequenceFile.Sorter's scream. * * <p>The default implementation reads the data into two {@link WritableComparable}s (using {@link * Writable#readFields(DataInput)}, then calls {@link * #compare(WritableComparable,WritableComparable)}. */ public int compare(byte[] b1, int s1, int l1, byte[] b2, int s2, int l2) { try { buffer.reset(b1, s1, l1); // parse key1 key1.readFields(buffer); buffer.reset(b2, s2, l2); // parse key2 key2.readFields(buffer); } catch (IOException e) { throw new RuntimeException(e); } return compare(key1, key2); // compare them }
/** 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()); }