1 files changed, 169 insertions, 0 deletions
diff --git a/container-search/src/main/java/com/yahoo/fs4/MapEncoder.java b/container-search/src/main/java/com/yahoo/fs4/MapEncoder.java
new file mode 100644
index 00000000000..948c537f068
--- /dev/null
+++ b/container-search/src/main/java/com/yahoo/fs4/MapEncoder.java
@@ -0,0 +1,169 @@
+// Copyright 2016 Yahoo Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.fs4;
+
+import com.yahoo.tensor.Tensor;
+import com.yahoo.tensor.serialization.TypedBinaryFormat;
+import com.yahoo.text.Utf8;
+
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * A static utility for encoding values to the binary map representation used in fs4 packets.
+ *
+ * @author <a href="mailto:bratseth@yahoo-inc.com">Jon Bratseth</a>
+ */
+public class MapEncoder {
+
+    // TODO: Time to refactor
+
+    private static final String TYPE_SUFFIX = ".type";
+    private static final String TENSOR_TYPE = "tensor";
+
+    /**
+     * Encodes a single value as a complete binary map.
+     * Does nothing if the value is null.
+     *
+     * Returns the number of maps encoded - 0 or 1
+     */
+    public static int encodeSingleValue(String mapName, String key, Object value, ByteBuffer buffer) {
+        if (value == null) return 0;
+
+        byte [] utf8 = Utf8.toBytes(mapName);
+        buffer.putInt(utf8.length);
+        buffer.put(utf8);
+        buffer.putInt(1);
+        utf8 = Utf8.toBytes(key);
+        buffer.putInt(utf8.length);
+        buffer.put(utf8);
+        utf8 = Utf8.toBytes(value.toString());
+        buffer.putInt(utf8.length);
+        buffer.put(utf8);
+
+        return 1;
+    }
+
+    /**
+     * Encodes a map as binary.
+     * Does nothing if the value is null.
+     *
+     * Returns the number of maps encoded - 0 or 1
+     */
+    public static int encodeMap(String mapName, Map<String,?> map, ByteBuffer buffer) {
+        if (map.isEmpty()) return 0;
+
+        byte [] utf8 = Utf8.toBytes(mapName);
+        buffer.putInt(utf8.length);
+        buffer.put(utf8);
+        buffer.putInt(map.size());
+        for (Map.Entry<String, ?> property : map.entrySet()) {
+            String key = property.getKey();
+            utf8 = Utf8.toBytes(key);
+            buffer.putInt(utf8.length);
+            buffer.put(utf8);
+            utf8 = Utf8.toBytes(property.getValue() != null ? property.getValue().toString() : "");
+            buffer.putInt(utf8.length);
+            buffer.put(utf8);
+        }
+
+        return 1;
+    }
+
+    /**
+     * Encodes a multi-map as binary.
+     * Does nothing if the value is null.
+     *
+     * Returns the number of maps encoded - 0 or 1
+     */
+    public static int encodeStringMultiMap(String mapName, Map<String,List<String>> map, ByteBuffer buffer) {
+        if (map.isEmpty()) return 0;
+
+        byte [] utf8 = Utf8.toBytes(mapName);
+        buffer.putInt(utf8.length);
+        buffer.put(utf8);
+        buffer.putInt(countStringEntries(map));
+        for (Map.Entry<String, List<String>> property : map.entrySet()) {
+            String key = property.getKey();
+            for (Object value : property.getValue()) {
+                utf8 = Utf8.toBytes(key);
+                buffer.putInt(utf8.length);
+                buffer.put(utf8);
+                utf8 = Utf8.toBytes(value.toString());
+                buffer.putInt(utf8.length);
+                buffer.put(utf8);
+            }
+        }
+
+        return 1;
+    }
+
+    /**
+     * Encodes a multi-map as binary.
+     * Does nothing if the value is null.
+     *
+     * Returns the number of maps encoded - 0 or 1
+     */
+    public static int encodeObjectMultiMap(String mapName, Map<String,List<Object>> map, ByteBuffer buffer) {
+        if (map.isEmpty()) return 0;
+
+        byte [] utf8 = Utf8.toBytes(mapName);
+        buffer.putInt(utf8.length);
+        buffer.put(utf8);
+        addTensorTypeInfo(map);
+        buffer.putInt(countObjectEntries(map));
+        for (Map.Entry<String, List<Object>> property : map.entrySet()) {
+            String key = property.getKey();
+            for (Object value : property.getValue()) {
+                utf8 = Utf8.toBytes(key);
+                buffer.putInt(utf8.length);
+                buffer.put(utf8);
+                if (value instanceof Tensor) {
+                    utf8 = TypedBinaryFormat.encode((Tensor)value);
+                } else {
+                    utf8 = Utf8.toBytes(value.toString());
+                }
+                buffer.putInt(utf8.length);
+                buffer.put(utf8);
+            }
+        }
+
+        return 1;
+    }
+
+    private static void addTensorTypeInfo(Map<String, List<Object>> map) {
+        Map<String, Tensor> tensorsToTag = new HashMap<>();
+        for (Map.Entry<String, List<Object>> entry : map.entrySet()) {
+            for (Object value : entry.getValue()) {
+                if (value instanceof Tensor) {
+                    tensorsToTag.put(entry.getKey(), (Tensor)value);
+                }
+            }
+        }
+        for (Map.Entry<String, Tensor> entry : tensorsToTag.entrySet()) {
+            // Ensure that we only have a single tensor associated with each key
+            map.put(entry.getKey(), Arrays.asList(entry.getValue()));
+            map.put(entry.getKey() + TYPE_SUFFIX, Arrays.asList(TENSOR_TYPE));
+        }
+    }
+
+    private static int countStringEntries(Map<String, List<String>> value) {
+        int entries = 0;
+        for (Map.Entry<String, List<String>> property : value.entrySet())
+            entries += property.getValue().size();
+        return entries;
+    }
+
+    private static int countObjectEntries(Map<String, List<Object>> value) {
+        int entries = 0;
+        for (Map.Entry<String, List<Object>> property : value.entrySet())
+            entries += property.getValue().size();
+        return entries;
+    }
+
+}