Add ByteBufferSizedHashed

Like HashedToByteBuffer, but param is a size function instead of a fixed length

virtdata-lib-basics/src/main/java/io/nosqlbench/virtdata/library/basics/shared/from_long/to_bytebuffer/ByteBufferSizedHashed.java

@@ -0,0 +1,63 @@
+package io.nosqlbench.virtdata.library.basics.shared.from_long.to_bytebuffer;
+
+import io.nosqlbench.virtdata.api.annotations.Categories;
+import io.nosqlbench.virtdata.api.annotations.Category;
+import io.nosqlbench.virtdata.api.annotations.Example;
+import io.nosqlbench.virtdata.api.annotations.ThreadSafeMapper;
+import io.nosqlbench.virtdata.api.bindings.VirtDataConversions;
+import io.nosqlbench.virtdata.library.basics.shared.from_long.to_long.Hash;
+
+import java.nio.ByteBuffer;
+import java.util.HashMap;
+import java.util.function.LongFunction;
+import java.util.function.LongToIntFunction;
+/**
+        * Create a ByteBuffer from a long input based on a provided size function.
+        *
+        * As a 'Sized' function, the first argument is a function which determines the size of the resulting ByteBuffer.
+        *
+        * As a 'Hashed' function, the input value is hashed again before being used as value.
+        */
+@Categories(Category.conversion)
+@ThreadSafeMapper
+public class ByteBufferSizedHashed implements LongFunction<ByteBuffer> {
+
+    private final LongToIntFunction sizeFunc;
+    private final Hash hash = new Hash();
+
+
+    @Example({
+            "ByteBufferSizedHashed(16)",
+            "Functionally identical to HashedtoByteBuffer(16) but using dynamic sizing implementation"
+
+
+    })
+    @Example({
+            "ByteBufferSizedHashed(HashRange(10, 14))",
+            "Create a ByteBuffer with variable limit (10 to 14)"
+    })
+    public ByteBufferSizedHashed(int size) {
+        this.sizeFunc = s -> size;
+    }
+    public ByteBufferSizedHashed(Object sizeFunc) {
+        this.sizeFunc = VirtDataConversions.adaptFunction(sizeFunc, LongToIntFunction.class);
+    }
+
+
+    @Override
+    public ByteBuffer apply(long input) {
+        int length = sizeFunc.applyAsInt(input);
+
+        int longs = (length / Long.BYTES) +1;
+        int bytes = longs * Long.BYTES;
+
+        ByteBuffer buffer = ByteBuffer.allocate(bytes);
+        for (int i = 0; i < longs; i++) {
+            long l = hash.applyAsLong(input + i);
+            buffer.putLong(l);
+        }
+        buffer.flip();
+        buffer.limit(length);
+        return buffer;
+    }
+}

virtdata-lib-basics/src/test/java/io/nosqlbench/virtdata/library/basics/shared/from_long/to_bytebuffer/ByteBufferSizedHashedTest.java

@@ -0,0 +1,23 @@
+package io.nosqlbench.virtdata.library.basics.shared.from_long.to_bytebuffer;
+
+import io.nosqlbench.virtdata.library.basics.shared.from_long.to_int.HashRange;
+import org.junit.Test;
+
+import java.nio.ByteBuffer;
+import java.util.function.LongToIntFunction;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class ByteBufferSizedHashedTest {
+
+    @Test
+    public void testWithHashRange() {
+        LongToIntFunction sizeFunc = new HashRange(100, 1000);
+        long input = 233423L;
+
+        ByteBufferSizedHashed d1 = new ByteBufferSizedHashed(sizeFunc);
+        ByteBuffer buf = d1.apply(input);
+        assertThat(sizeFunc.applyAsInt(233423L)).isEqualTo(buf.remaining());
+    }
+
+}