public SpillMap(SpillFile file, int thresholdBytes) throws IOException {
this.thresholdBytes = thresholdBytes;
this.spillFile = file;
byteMap = MappedByteBufferMap.newMappedByteBufferMap(thresholdBytes, spillFile);
bFilters = Lists.newArrayList();
bFilters.add(BloomFilter.create(Funnels.byteArrayFunnel(), 1000));
}
// Funtion checks if current page has enough space to fit the new serialized tuple
// If not it flushes the current buffer and gets a new page
// TODO: The code does not ensure that pages are optimally packed.
// It only tries to fill up the current page as much as possbile, if its
// exhausted it requests a new page. Instead it would be nice to load the next page
// that could fit the new value.
private void ensureSpace(byte[] value) {
if (!byteMap.canFit(value)) {
// Flush current buffer
byteMap.flushBuffer();
// Get next page
byteMap = MappedByteBufferMap.newMappedByteBufferMap(thresholdBytes, spillFile);
// Create new bloomfilter
bFilters.add(BloomFilter.create(Funnels.byteArrayFunnel(), 1000));
}
}
private TitleNameNormalizer(String pathToEvaluationRedirectsData) throws IOException {
if (useBloomFilter) {
redirectFilter = BloomFilter.create(Funnels.stringFunnel(), ESTIMATED_REDIRECTS);
redirects =
new LRUCache<String, String>(5000) {
protected String loadValue(String src) {
String normalized = TitleNameIndexer.normalize(src);
if (normalized == null) return src;
return TitleNameIndexer.normalize(src);
}
};
} else redirects = new StringMap<String>();
if (showInitProgress)
System.out.println(
"Loading the most recent redirect pages from Wikipedia to normalize the output links to the latest version");
if (pathToEvaluationRedirectsData != null) {
InputStream is = CompressionUtils.readSnappyCompressed(pathToEvaluationRedirectsData);
LineIterator iterator = IOUtils.lineIterator(is, StandardCharsets.UTF_8);
long linecount = 0;
while (iterator.hasNext()) {
String line = iterator.nextLine();
if (showInitProgress && linecount++ % 100000 == 0)
System.out.println("loading the latest redirects; linecount=" + linecount);
String[] parts = StringUtils.split(line, '\t');
String src = parts[0].trim().replace(' ', '_');
String trg = parts[1].trim().replace(' ', '_');
if (useBloomFilter) redirectFilter.put(src);
else redirects.put(src, trg);
}
iterator.close();
}
redirects = Collections.unmodifiableMap(redirects);
if (showInitProgress)
System.out.println(
"Done - Loading the most recent redirect pages from Wikipedia to normalize the output links to the latest version");
}
/** For comparing the load differences between consistent hash and HRW */
public class Compare {
private static final HashFunction hfunc = Hashing.murmur3_128();
private static final Funnel<CharSequence> strFunnel =
Funnels.stringFunnel(Charset.defaultCharset());
public static void main(String[] args) {
Map<String, AtomicInteger> distribution = Maps.newHashMap();
System.out.println("======: ConsistentHash :========");
ConsistentHash<String, String> c =
new ConsistentHash(hfunc, strFunnel, strFunnel, getNodes(distribution));
for (int i = 0; i < 10000; i++) {
distribution.get(c.get("" + i)).incrementAndGet();
}
for (Entry<String, AtomicInteger> e : distribution.entrySet()) {
System.out.println(e.getKey() + "," + e.getValue().get());
e.getValue().set(0);
}
System.out.println("====== remove 2 ========");
for (int i = 0; i < 2; i++) {
c.remove("Node" + i);
distribution.remove("Node" + i);
}
for (int i = 0; i < 10000; i++) {
distribution.get(c.get("" + i)).incrementAndGet();
}
for (Entry<String, AtomicInteger> e : distribution.entrySet()) {
System.out.println(e.getKey() + "," + e.getValue().get());
}
System.out.println("======: RendezvousHash :========");
distribution = Maps.newHashMap();
RendezvousHash<String, String> r =
new RendezvousHash(hfunc, strFunnel, strFunnel, getNodes(distribution));
for (int i = 0; i < 10000; i++) {
distribution.get(r.get("" + i)).incrementAndGet();
}
for (Entry<String, AtomicInteger> e : distribution.entrySet()) {
System.out.println(e.getKey() + "," + e.getValue().get());
e.getValue().set(0);
}
System.out.println("====== remove 2 ========");
for (int i = 0; i < 2; i++) {
r.remove("Node" + i);
distribution.remove("Node" + i);
}
for (int i = 0; i < 10000; i++) {
distribution.get(r.get("" + i)).incrementAndGet();
}
for (Entry<String, AtomicInteger> e : distribution.entrySet()) {
System.out.println(e.getKey() + "," + e.getValue().get());
}
}
private static List<String> getNodes(Map<String, AtomicInteger> distribution) {
List<String> nodes = Lists.newArrayList();
for (int i = 0; i < 5; i++) {
nodes.add("Node" + i);
distribution.put("Node" + i, new AtomicInteger());
}
return nodes;
}
}
/**
* Hashes the contents of this byte source using the given hash function.
*
* @throws IOException if an I/O error occurs in the process of reading from this source
*/
public HashCode hash(HashFunction hashFunction) throws IOException {
Hasher hasher = hashFunction.newHasher();
copyTo(Funnels.asOutputStream(hasher));
return hasher.hash();
}
private void createNewBloomFilter(int expectedInsertions) throws IOException {
bloomFilter =
BloomFilter.create(
Funnels.byteArrayFunnel(), expectedInsertions, FALSE_POSITIVE_PROBABILITY);
this.persistBloomFilter();
}
