1 files changed, 95 insertions, 0 deletions
diff --git a/container-search/src/main/java/com/yahoo/search/searchers/ValidateFuzzySearcher.java b/container-search/src/main/java/com/yahoo/search/searchers/ValidateFuzzySearcher.java
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+++ b/container-search/src/main/java/com/yahoo/search/searchers/ValidateFuzzySearcher.java
@@ -0,0 +1,95 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.search.searchers;
+
+import com.yahoo.prelude.query.FuzzyItem;
+import com.yahoo.prelude.query.Item;
+import com.yahoo.prelude.query.ToolBox;
+import com.yahoo.search.Query;
+import com.yahoo.search.Result;
+import com.yahoo.search.Searcher;
+import com.yahoo.search.grouping.vespa.GroupingExecutor;
+import com.yahoo.search.query.ranking.RankProperties;
+import com.yahoo.search.result.ErrorMessage;
+import com.yahoo.search.searchchain.Execution;
+import com.yahoo.vespa.config.search.AttributesConfig;
+import com.yahoo.yolean.chain.Before;
+
+import java.util.HashSet;
+import java.util.Optional;
+import java.util.Set;
+
+/**
+ * Validates any FuzzyItem query items.
+ *
+ * @author alexeyche
+ */
+@Before(GroupingExecutor.COMPONENT_NAME) // Must happen before query.prepare()
+public class ValidateFuzzySearcher extends Searcher {
+
+    private final Set<String> validAttributes = new HashSet<>();
+
+    public ValidateFuzzySearcher(AttributesConfig attributesConfig) {
+        for (AttributesConfig.Attribute a : attributesConfig.attribute()) {
+            if (a.datatype() == AttributesConfig.Attribute.Datatype.STRING) {
+                validAttributes.add(a.name());
+            }
+        }
+    }
+
+    @Override
+    public Result search(Query query, Execution execution) {
+        Optional<ErrorMessage> e = validate(query);
+        return e.isEmpty() ? execution.search(query) : new Result(query, e.get());
+    }
+
+    private Optional<ErrorMessage> validate(Query query) {
+        FuzzyVisitor visitor = new FuzzyVisitor(query.getRanking().getProperties(), validAttributes, query);
+        ToolBox.visit(visitor, query.getModel().getQueryTree().getRoot());
+        return visitor.errorMessage;
+    }
+
+    private static class FuzzyVisitor extends ToolBox.QueryVisitor {
+
+        public Optional<ErrorMessage> errorMessage = Optional.empty();
+
+        private final Set<String> validAttributes;
+        private final Query query;
+
+        public FuzzyVisitor(RankProperties rankProperties, Set<String> validAttributes, Query query) {
+            this.validAttributes = validAttributes;
+            this.query = query;
+        }
+
+        @Override
+        public boolean visit(Item item) {
+            if (item instanceof FuzzyItem) {
+                String error = validate((FuzzyItem)item);
+                if (error != null)
+                    errorMessage = Optional.of(ErrorMessage.createIllegalQuery(error));
+            }
+            return true;
+        }
+
+        /** Returns an error message if this is invalid, or null if it is valid */
+        private String validate(FuzzyItem item) {
+            if (!validAttributes.contains(item.getIndexName())) {
+                return item + " field is not a string attribute";
+            }
+            if (item.getPrefixLength() < 0) {
+                return item + " has invalid prefixLength " + item.getPrefixLength() + ": Must be >= 0";
+            }
+            if (item.getMaxEditDistance() < 0) {
+                return item + " has invalid maxEditDistance " + item.getMaxEditDistance() + ": Must be >= 0";
+            }
+            if (item.stringValue().isEmpty()) {
+                return item + " fuzzy query must be non-empty";
+            }
+            return null;
+        }
+
+        @Override
+        public void onExit() {}
+
+    }
+
+}