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Generic Recordinality supporting String, Long, or Integer elements #2

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Generic Recordinality supporting String, Long, or Integer elements #2

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21 changes: 15 additions & 6 deletions src/main/java/com/cscotta/recordinality/Recordinality.java
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Original file line number Diff line number Diff line change
Expand Up @@ -25,7 +25,7 @@
import com.google.common.hash.HashFunction;
import com.google.common.collect.ImmutableSet;

public class Recordinality {
public class Recordinality<T> {

private final int sampleSize;
private final int seed = new Random().nextInt();
Expand All @@ -46,7 +46,7 @@ public Recordinality(int sampleSize) {
/*
* Observes a value in a stream.
*/
public void observe(String element) {
public void observe(T element) {
boolean inserted = insertIfFits(element);
if (inserted) modifications.incrementAndGet();
}
Expand Down Expand Up @@ -84,8 +84,17 @@ public Set<Element> getSample() {
/*
* Inserts a record into our k-set if it fits.
*/
private boolean insertIfFits(String element) {
long hashedValue = hash.hashString(element).asLong();
private boolean insertIfFits(T element) {
long hashedValue = 0L;

if (element.getClass() == String.class)
hashedValue = hash.hashString((String)element).asLong();
else if (element.getClass() == Long.class)
hashedValue = hash.hashLong((Long)element).asLong();
else if (element.getClass() == Integer.class)
hashedValue = hash.hashInt((Integer)element).asLong();
else
throw new ClassCastException();

// Short-circuit if our k-set is saturated. Common case.
if (hashedValue < cachedMin.get() && kMapSize >= sampleSize)
Expand Down Expand Up @@ -141,10 +150,10 @@ public String toString() {
*/
public class Element {

public final String value;
public final T value;
public final AtomicLong count;

public Element(String value) {
public Element(T value) {
this.value = value;
this.count = new AtomicLong(1);
}
Expand Down
2 changes: 1 addition & 1 deletion src/test/java/com/cscotta/recordinality/RecordinalityTest.java
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Expand Up @@ -67,7 +67,7 @@ public Result call() throws Exception {
long start = System.currentTimeMillis();
final double[] results = new double[numRuns];
for (int i = 0; i < numRuns; i++) {
Recordinality rec = new Recordinality(kSize);
Recordinality rec = new Recordinality<String>(kSize);
for (String line : lines) rec.observe(line);
results[i] = rec.estimateCardinality();
}
Expand Down