1 files changed, 65 insertions, 0 deletions
diff --git a/document/src/main/java/com/yahoo/document/json/readers/TensorReader.java b/document/src/main/java/com/yahoo/document/json/readers/TensorReader.java
new file mode 100644
index 00000000000..5dd32753ed6
--- /dev/null
+++ b/document/src/main/java/com/yahoo/document/json/readers/TensorReader.java
@@ -0,0 +1,65 @@
+// Copyright 2017 Yahoo Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.document.json.readers;
+
+import com.yahoo.document.datatypes.TensorFieldValue;
+import com.yahoo.document.json.TokenBuffer;
+import com.yahoo.tensor.MappedTensor;
+import com.yahoo.tensor.Tensor;
+
+import static com.yahoo.document.json.readers.JsonParserHelpers.*;
+
+public class TensorReader {
+    public static final String TENSOR_ADDRESS = "address";
+    public static final String TENSOR_DIMENSIONS = "dimensions";
+    public static final String TENSOR_CELLS = "cells";
+    public static final String TENSOR_VALUE = "value";
+
+    public static void fillTensor(TokenBuffer buffer, TensorFieldValue tensorFieldValue) {
+        Tensor.Builder tensorBuilder = Tensor.Builder.of(tensorFieldValue.getDataType().getTensorType());
+        expectObjectStart(buffer.currentToken());
+        int initNesting = buffer.nesting();
+        /* read tensor cell fields and ignore everything else */
+        for (buffer.next(); buffer.nesting() >= initNesting; buffer.next()) {
+            if (TensorReader.TENSOR_CELLS.equals(buffer.currentName()))
+                readTensorCells(buffer, tensorBuilder);
+        }
+        expectObjectEnd(buffer.currentToken());
+        tensorFieldValue.assign(tensorBuilder.build());
+    }
+
+    public static void readTensorCells(TokenBuffer buffer, Tensor.Builder tensorBuilder) {
+        expectArrayStart(buffer.currentToken());
+        int initNesting = buffer.nesting();
+        for (buffer.next(); buffer.nesting() >= initNesting; buffer.next())
+            readTensorCell(buffer, tensorBuilder);
+        expectCompositeEnd(buffer.currentToken());
+    }
+
+    public static void readTensorCell(TokenBuffer buffer, Tensor.Builder tensorBuilder) {
+        expectObjectStart(buffer.currentToken());
+        int initNesting = buffer.nesting();
+        double cellValue = 0.0;
+        Tensor.Builder.CellBuilder cellBuilder = tensorBuilder.cell();
+        for (buffer.next(); buffer.nesting() >= initNesting; buffer.next()) {
+            String currentName = buffer.currentName();
+            if (TensorReader.TENSOR_ADDRESS.equals(currentName)) {
+                readTensorAddress(buffer, cellBuilder);
+            } else if (TensorReader.TENSOR_VALUE.equals(currentName)) {
+                cellValue = Double.valueOf(buffer.currentText());
+            }
+        }
+        expectObjectEnd(buffer.currentToken());
+        cellBuilder.value(cellValue);
+    }
+
+    public static void readTensorAddress(TokenBuffer buffer, MappedTensor.Builder.CellBuilder cellBuilder) {
+        expectObjectStart(buffer.currentToken());
+        int initNesting = buffer.nesting();
+        for (buffer.next(); buffer.nesting() >= initNesting; buffer.next()) {
+            String dimension = buffer.currentName();
+            String label = buffer.currentText();
+            cellBuilder.label(dimension, label);
+        }
+        expectObjectEnd(buffer.currentToken());
+    }
+}