generalize op source

engine-api/src/main/java/io/nosqlbench/engine/api/activityapi/planning/OpSequence.java

@@ -23,19 +23,10 @@ import java.util.function.Function;
 /**
  * An OpSequence provides fast access to a set of operations in a specific
  * order.
+ *
  * @param <T> The type of element which is to be sequenced
  */
-public interface OpSequence<T> {
-
-    /**
-     * Get the next operation for the given long value. This is simply
-     * the offset indicated by the offset sequence array at a modulo
-     * position.
-     *
-     * @param selector the long value that determines the next op
-     * @return An op of type T
-     */
-    T get(long selector);
+public interface OpSequence<T> extends OpSource<T> {
 
     /**
      * Get the list of individual operations which could be returned by {@link #get(long)}.

engine-api/src/main/java/io/nosqlbench/engine/api/activityapi/planning/OpSource.java

@@ -0,0 +1,27 @@
+package io.nosqlbench.engine.api.activityapi.planning;
+
+import java.util.function.LongFunction;
+
+/**
+ * An OpSource provides an Op when given an ordinal.
+ * OpSources are expected to be deterministic with respect to inputs.
+ *
+ * @param <T>
+ */
+public interface OpSource<T> extends LongFunction<T> {
+
+    /**
+     * Get the next operation for the given long value. This is simply
+     * the offset indicated by the offset sequence array at a modulo
+     * position.
+     *
+     * @param selector the long value that determines the next op
+     * @return An op of type T
+     */
+    T get(long selector);
+
+    @Override
+    default T apply(long value) {
+        return get(value);
+    }
+}