1 files changed, 63 insertions, 0 deletions
diff --git a/container-search/src/main/java/com/yahoo/search/query/profile/PrefixQueryProfileVisitor.java b/container-search/src/main/java/com/yahoo/search/query/profile/PrefixQueryProfileVisitor.java
new file mode 100644
index 00000000000..2a22d58d8b7
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+++ b/container-search/src/main/java/com/yahoo/search/query/profile/PrefixQueryProfileVisitor.java
@@ -0,0 +1,63 @@
+// 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;
+
+import com.yahoo.processing.request.CompoundName;
+
+/**
+ * A query profile visitor which keeps track of name prefixes and can skip values outside a given prefix
+ *
+ * @author <a href="mailto:bratseth@yahoo-inc.com">Jon Bratseth</a>
+ */
+abstract class PrefixQueryProfileVisitor extends QueryProfileVisitor {
+
+    /** Only call onValue/onQueryProfile for nodes having this prefix */
+    private final CompoundName prefix;
+
+    /** The current prefix, relative to prefix. */
+    protected CompoundName currentPrefix = CompoundName.empty;
+
+    private int prefixComponentIndex = -1;
+
+    public PrefixQueryProfileVisitor(CompoundName prefix) {
+        if (prefix == null)
+            prefix = CompoundName.empty;
+        this.prefix = prefix;
+    }
+
+    @Override
+    public final void onQueryProfile(QueryProfile profile, DimensionBinding binding, QueryProfile owner) {
+        if (prefixComponentIndex < prefix.size()) return; // Not in the prefix yet
+        onQueryProfileInsidePrefix(profile, binding, owner);
+    }
+
+    protected abstract void onQueryProfileInsidePrefix(QueryProfile profile, DimensionBinding binding, QueryProfile owner);
+
+    @Override
+    public final boolean enter(String name) {
+        prefixComponentIndex++;
+        if (prefixComponentIndex-1 < prefix.size()) return true; // we're in the given prefix, which should not be included in the name
+        currentPrefix = currentPrefix.append(name);
+        return true;
+    }
+
+    @Override
+    public final void leave(String name) {
+        prefixComponentIndex--;
+        if (prefixComponentIndex < prefix.size()) return; // we're in the given prefix, which should not be included in the name
+        if ( ! name.isEmpty() && ! currentPrefix.isEmpty())
+            currentPrefix = currentPrefix.first(currentPrefix.size() - 1);
+    }
+
+    /**
+     * Returns the correct prefix component if we are still going down the prefix path,
+     * or null to get all if we are inside the prefix
+     */
+    @Override
+    public String getLocalKey() {
+        if (prefixComponentIndex < prefix.size())
+            return prefix.get(prefixComponentIndex);
+        else
+            return null;
+    }
+
+}