Updating MurmurHash3V2 to throw exception if input array is empty or
null or if input Memory is not on-heap.
diff --git a/src/main/java/org/apache/datasketches/hash/MurmurHash3v2.java b/src/main/java/org/apache/datasketches/hash/MurmurHash3v2.java
index f7bf205..d2500df 100644
--- a/src/main/java/org/apache/datasketches/hash/MurmurHash3v2.java
+++ b/src/main/java/org/apache/datasketches/hash/MurmurHash3v2.java
@@ -34,7 +34,7 @@
* MurmurHash3_x64_128(...), final revision 150</a>,
* which is in the Public Domain, was the inspiration for this implementation in Java.</p>
*
- * <p>This implementation of the MurmurHash3 allows hashing of a block of Memory defined by an offset
+ * <p>This implementation of the MurmurHash3 allows hashing of a block of on-heap Memory defined by an offset
* and length. The calling API also allows the user to supply the small output array of two longs,
* so that the entire hash function is static and free of object allocations.</p>
*
@@ -59,7 +59,7 @@
*/
public static long[] hash(final long[] in, final long seed) {
if ((in == null) || (in.length == 0)) {
- return emptyOrNull(seed, new long[2]);
+ emptyOrNull();
}
return hash(Memory.wrap(in), 0L, in.length << 3, seed, new long[2]);
}
@@ -74,7 +74,7 @@
*/
public static long[] hash(final int[] in, final long seed) {
if ((in == null) || (in.length == 0)) {
- return emptyOrNull(seed, new long[2]);
+ emptyOrNull();
}
return hash(Memory.wrap(in), 0L, in.length << 2, seed, new long[2]);
}
@@ -89,7 +89,7 @@
*/
public static long[] hash(final char[] in, final long seed) {
if ((in == null) || (in.length == 0)) {
- return emptyOrNull(seed, new long[2]);
+ emptyOrNull();
}
return hash(Memory.wrap(in), 0L, in.length << 1, seed, new long[2]);
}
@@ -104,7 +104,7 @@
*/
public static long[] hash(final byte[] in, final long seed) {
if ((in == null) || (in.length == 0)) {
- return emptyOrNull(seed, new long[2]);
+ emptyOrNull();
}
return hash(Memory.wrap(in), 0L, in.length, seed, new long[2]);
}
@@ -150,7 +150,7 @@
*/
public static long[] hash(final String in, final long seed, final long[] hashOut) {
if ((in == null) || (in.length() == 0)) {
- return emptyOrNull(seed, hashOut);
+ emptyOrNull();
}
final byte[] byteArr = in.getBytes(UTF_8);
return hash(Memory.wrap(byteArr), 0L, byteArr.length, seed, hashOut);
@@ -161,7 +161,7 @@
/**
* Returns a 128-bit hash of the input as a long array of size 2.
*
- * @param mem The input Memory. Must be non-null and non-empty.
+ * @param mem The input on-heap Memory. Must be non-null and non-empty.
* @param offsetBytes the starting point within Memory.
* @param lengthBytes the total number of bytes to be hashed.
* @param seed A long valued seed.
@@ -171,10 +171,9 @@
@SuppressWarnings("restriction")
public static long[] hash(final Memory mem, final long offsetBytes, final long lengthBytes,
final long seed, final long[] hashOut) {
- if ((mem == null) || (mem.getCapacity() == 0L)) {
- return emptyOrNull(seed, hashOut);
- }
- final Object uObj = ((WritableMemory) mem).getArray(); //may be null
+ if ((mem == null) || (mem.getCapacity() == 0L)) { emptyOrNull(); }
+ final Object uObj = ((WritableMemory) mem).getArray();
+ if (uObj == null) { emptyOrNull(); }
long cumOff = mem.getCumulativeOffset() + offsetBytes;
long h1 = seed;
@@ -355,7 +354,7 @@
return hashOut;
}
- private static long[] emptyOrNull(final long seed, final long[] hashOut) {
- return finalMix128(seed, seed, 0, hashOut);
+ private static void emptyOrNull() {
+ throw new IllegalArgumentException("Input is empty, null or mem is not on-heap.");
}
}
