1 files changed, 87 insertions, 0 deletions
diff --git a/container-search/src/main/java/com/yahoo/search/query/profile/QueryProfileVisitor.java b/container-search/src/main/java/com/yahoo/search/query/profile/QueryProfileVisitor.java
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+++ b/container-search/src/main/java/com/yahoo/search/query/profile/QueryProfileVisitor.java
@@ -0,0 +1,87 @@
+// Copyright 2016 Yahoo Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.search.query.profile;
+
+/**
+ * Instances of this is used to visit nodes in a graph of query profiles
+ *
+ * <code>
+ * Visitor are called in the following sequence on each query profile:
+ * enter=enter(referenceName);
+ * onQueryProfile(this)
+ * if (enter) {
+ *   getLocalKey()
+ *     ...calls on nested content found in variants, this and inherited, in that order
+ *   leave(referenceName)
+ * }
+ *
+ * The first enter call will be on the root node, which has an empt reference name.
+ * </code>
+ *
+ * @author <a href="mailto:bratseth@yahoo-inc.com">Jon Bratseth</a>
+ */
+abstract class QueryProfileVisitor {
+
+    /**
+     * Called when a new <b>nested</b> profile in the graph is entered.
+     * This default implementation does nothing but returning true.
+     * If the node is entered (if true is returned from this), a corresponding {@link #leave(String)} call will happen
+     * later.
+     *
+     * @param name the name this profile is nested as, or the empty string if we are entering the root profile
+     * @return whether we should visit the content of this node or not
+     */
+    public boolean enter(String name) { return true; }
+
+    /**
+     * Called when the last {@link #enter(String) entered} nested profile is left.
+     * That is: One leave call is made for each enter call which returns true,
+     * but due to nesting those calls are not necessarily alternating.
+     * This default implementation does nothing.
+     */
+    public void leave(String name) { }
+
+    /**
+     * Called when a value (not a query profile) is encountered.
+     *
+     * @param localName the local name of this value (the full name, if needed, must be reconstructed
+     *        by the information given by the history of {@link #enter(String)} and {@link #leave(String)} calls
+     * @param value the value
+     * @param binding the binding this holds for
+     * @param owner the query profile having this value, or null only when profile is the root profile
+     */
+    public abstract void onValue(String localName, Object value, DimensionBinding binding, QueryProfile owner);
+
+    /**
+     * Called when a query profile is encountered.
+     *
+     * @param profile the query profile reference encountered
+     * @param binding the binding this holds for
+     * @param owner the profile making this reference, or null only when profile is the root profile
+     */
+    public abstract void onQueryProfile(QueryProfile profile, DimensionBinding binding, QueryProfile owner);
+
+    /** Returns whether this visitor is done visiting what it needed to visit at this point */
+    public abstract boolean isDone();
+
+    /** Returns whether we should, at this point, visit inherited profiles. This default implementation returns true */
+    public boolean visitInherited() { return true; }
+
+    /**
+     * Returns the current local key which should be visited in the last {@link #enter(String) entered} sub-profile
+     * (or in the top level profile if none is entered), or null to visit all content
+     */
+    public abstract String getLocalKey();
+
+    /** Calls onValue or onQueryProfile on this and visits the content if it's a profile */
+    final void acceptValue(String key, Object value, DimensionBinding dimensionBinding, QueryProfile owner) {
+        if (value==null) return;
+        if (value instanceof QueryProfile) {
+            QueryProfile queryProfileValue=(QueryProfile)value;
+            queryProfileValue.acceptAndEnter(key, this, dimensionBinding.createFor(queryProfileValue.getDimensions()), owner);
+        }
+        else {
+            onValue(key, value, dimensionBinding, owner);
+        }
+    }
+
+}