/** the test */
@Test
@SuppressWarnings("unchecked")
public void testSortedMapWritable() {
Text[] keys = {
new Text("key1"), new Text("key2"), new Text("key3"),
};
BytesWritable[] values = {
new BytesWritable("value1".getBytes()),
new BytesWritable("value2".getBytes()),
new BytesWritable("value3".getBytes())
};
SortedMapWritable inMap = new SortedMapWritable();
for (int i = 0; i < keys.length; i++) {
inMap.put(keys[i], values[i]);
}
assertEquals(0, inMap.firstKey().compareTo(keys[0]));
assertEquals(0, inMap.lastKey().compareTo(keys[2]));
SortedMapWritable outMap = new SortedMapWritable(inMap);
assertEquals(inMap.size(), outMap.size());
for (Map.Entry<WritableComparable, Writable> e : inMap.entrySet()) {
assertTrue(outMap.containsKey(e.getKey()));
assertEquals(0, ((WritableComparable) outMap.get(e.getKey())).compareTo(e.getValue()));
}
// Now for something a little harder...
Text[] maps = {new Text("map1"), new Text("map2")};
SortedMapWritable mapOfMaps = new SortedMapWritable();
mapOfMaps.put(maps[0], inMap);
mapOfMaps.put(maps[1], outMap);
SortedMapWritable copyOfMapOfMaps = new SortedMapWritable(mapOfMaps);
for (int i = 0; i < maps.length; i++) {
assertTrue(copyOfMapOfMaps.containsKey(maps[i]));
SortedMapWritable a = (SortedMapWritable) mapOfMaps.get(maps[i]);
SortedMapWritable b = (SortedMapWritable) copyOfMapOfMaps.get(maps[i]);
assertEquals(a.size(), b.size());
for (Writable key : a.keySet()) {
assertTrue(b.containsKey(key));
// This will work because we know what we put into each set
WritableComparable aValue = (WritableComparable) a.get(key);
WritableComparable bValue = (WritableComparable) b.get(key);
assertEquals(0, aValue.compareTo(bValue));
}
}
}
/**
* 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
}
@Override
public synchronized void append(WritableComparable key, Writable val) throws IOException {
super.append(key, val);
buf.reset();
key.write(buf);
bloomKey.set(byteArrayForBloomKey(buf), 1.0);
bloomFilter.add(bloomKey);
}
/**
* Checks if this MapFile has the indicated key. The membership test is performed using a Bloom
* filter, so the result has always non-zero probability of false positives.
*
* @param key key to check
* @return false iff key doesn't exist, true if key probably exists.
* @throws IOException
*/
public boolean probablyHasKey(WritableComparable key) throws IOException {
if (bloomFilter == null) {
return true;
}
buf.reset();
key.write(buf);
bloomKey.set(byteArrayForBloomKey(buf), 1.0);
return bloomFilter.membershipTest(bloomKey);
}
/**
* Compare two WritableComparables.
*
* <p>The default implementation uses the natural ordering, calling {@link
* Comparable#compareTo(Object)}.
*/
@SuppressWarnings("unchecked")
public int compare(WritableComparable a, WritableComparable b) {
return a.compareTo(b);
}
