1 files changed, 44 insertions, 0 deletions
diff --git a/predicate-search/src/main/java/com/yahoo/search/predicate/utils/VespaFeedParser.java b/predicate-search/src/main/java/com/yahoo/search/predicate/utils/VespaFeedParser.java
new file mode 100644
index 00000000000..8ba9236a66c
--- /dev/null
+++ b/predicate-search/src/main/java/com/yahoo/search/predicate/utils/VespaFeedParser.java
@@ -0,0 +1,44 @@
+// Copyright 2016 Yahoo Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.search.predicate.utils;
+
+import com.yahoo.document.predicate.Predicate;
+
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.function.Consumer;
+
+/**
+ * Parses a feed file containing documents in XML format. Its implementation is based on the following assumptions:
+ *  1. Each document has single predicate field.
+ *  2. The predicate is stored in a field named "boolean".
+ *
+ *  @author bjorncs
+ */
+public class VespaFeedParser {
+
+    public static int parseDocuments(String feedFile, int maxDocuments, Consumer<Predicate> consumer) throws IOException {
+        int documentCount = 0;
+        try (BufferedReader reader = new BufferedReader(new FileReader(feedFile), 8 * 1024)) {
+            reader.readLine();
+            reader.readLine(); // Skip to start of first document
+            String line = reader.readLine();
+            while (!line.startsWith("</vespafeed>") && documentCount < maxDocuments) {
+                while (!line.startsWith("<boolean>")) {
+                    line = reader.readLine();
+                }
+                Predicate predicate = Predicate.fromString(extractBooleanExpression(line));
+                consumer.accept(predicate);
+                ++documentCount;
+                while (!line.startsWith("<document") && !line.startsWith("</vespafeed>")) {
+                    line = reader.readLine();
+                }
+            }
+        }
+        return documentCount;
+    }
+
+    private static String extractBooleanExpression(String line) {
+        return line.substring(9, line.length() - 10);
+    }
+}