Disallow feeding empty indexed tensors

2 files changed, 41 insertions, 6 deletions

diff --git a/vespajlib/src/main/java/com/yahoo/tensor/serialization/JsonFormat.java b/vespajlib/src/main/java/com/yahoo/tensor/serialization/JsonFormat.java
index 80b37e43c3d..cb7539d8565 100644
--- a/vespajlib/src/main/java/com/yahoo/tensor/serialization/JsonFormat.java
+++ b/vespajlib/src/main/java/com/yahoo/tensor/serialization/JsonFormat.java
@@ -94,17 +94,17 @@ public class JsonFormat {
         else if (root.field("blocks").valid())
             decodeBlocks(root.field("blocks"), builder);
         else if (builder.type().dimensions().stream().anyMatch(d -> d.isIndexed())) // sparse can be empty
-            throw new IllegalArgumentException("Expected a tensor value to contain either 'cells' or 'values'");
+            throw new IllegalArgumentException("Expected a tensor value to contain either 'cells' or 'values' or 'blocks'");
         return builder.build();
     }
 
     private static void decodeCells(Inspector cells, Tensor.Builder builder) {
-        if ( cells.type() == Type.ARRAY)
+        if (cells.type() == Type.ARRAY)
             cells.traverse((ArrayTraverser) (__, cell) -> decodeCell(cell, builder));
         else if (cells.type() == Type.OBJECT)
             cells.traverse((ObjectTraverser) (key, value) -> decodeSingleDimensionCell(key, value, builder));
         else
-            throw new IllegalArgumentException("Excepted 'cells' to contain an array or obejct, not " + cells.type());
+            throw new IllegalArgumentException("Excepted 'cells' to contain an array or object, not " + cells.type());
     }
 
     private static void decodeCell(Inspector cell, Tensor.Builder builder) {
@@ -128,18 +128,23 @@ public class JsonFormat {
         IndexedTensor.BoundBuilder indexedBuilder = (IndexedTensor.BoundBuilder)builder;
         if (values.type() == Type.STRING) {
             double[] decoded = decodeHexString(values.asString(), builder.type().valueType());
+            if (decoded.length == 0)
+                throw new IllegalArgumentException("The 'values' string does not contain any values");
             for (int i = 0; i < decoded.length; i++) {
                 indexedBuilder.cellByDirectIndex(i, decoded[i]);
             }
             return;
         }
-        if ( values.type() != Type.ARRAY)
+        if (values.type() != Type.ARRAY)
             throw new IllegalArgumentException("Excepted 'values' to contain an array, not " + values.type());
+        if (values.entries() == 0)
+            throw new IllegalArgumentException("The 'values' array does not contain any values");
 
         MutableInteger index = new MutableInteger(0);
         values.traverse((ArrayTraverser) (__, value) -> {
-            if (value.type() != Type.LONG && value.type() != Type.DOUBLE)
+            if (value.type() != Type.LONG && value.type() != Type.DOUBLE) {
                 throw new IllegalArgumentException("Excepted the values array to contain numbers, not " + value.type());
+            }
             indexedBuilder.cellByDirectIndex(index.next(), value.asDouble());
         });
     }
@@ -167,7 +172,7 @@ public class JsonFormat {
 
     private static void decodeSingleDimensionBlock(String key, Inspector value, MixedTensor.BoundBuilder mixedBuilder) {
         if (value.type() != Type.ARRAY)
-            throw new IllegalArgumentException("Expected an item in a 'blocks' array to be an object, not " + value.type());
+            throw new IllegalArgumentException("Expected an item in a 'blocks' array to be an array, not " + value.type());
         mixedBuilder.block(asAddress(key, mixedBuilder.type().mappedSubtype()),
                            decodeValues(value, mixedBuilder));
     }
@@ -256,9 +261,15 @@ public class JsonFormat {
     private static double[] decodeValues(Inspector valuesField, MixedTensor.BoundBuilder mixedBuilder) {
         double[] values = new double[(int)mixedBuilder.denseSubspaceSize()];
         if (valuesField.type() == Type.ARRAY) {
+            if (valuesField.entries() == 0) {
+                throw new IllegalArgumentException("The 'block' value array does not contain any values");
+            }
             valuesField.traverse((ArrayTraverser) (index, value) -> values[index] = decodeNumeric(value));
         } else if (valuesField.type() == Type.STRING) {
             double[] decoded = decodeHexString(valuesField.asString(), mixedBuilder.type().valueType());
+            if (decoded.length == 0) {
+                throw new IllegalArgumentException("The 'block' value string does not contain any values");
+            }
             for (int i = 0; i < decoded.length; i++) {
                 values[i] = decoded[i];
             }
diff --git a/vespajlib/src/test/java/com/yahoo/tensor/serialization/JsonFormatTestCase.java b/vespajlib/src/test/java/com/yahoo/tensor/serialization/JsonFormatTestCase.java
index 2f1e3be9299..87796501917 100644
--- a/vespajlib/src/test/java/com/yahoo/tensor/serialization/JsonFormatTestCase.java
+++ b/vespajlib/src/test/java/com/yahoo/tensor/serialization/JsonFormatTestCase.java
@@ -68,6 +68,21 @@ public class JsonFormatTestCase {
     }
 
     @Test
+    public void testDisallowedEmptyDenseTensor() {
+        TensorType type = TensorType.fromSpec("tensor(x[3])");
+        assertDecodeFails(type, "{\"values\":[]}", "The 'values' array does not contain any values");
+        assertDecodeFails(type, "{\"values\":\"\"}", "The 'values' string does not contain any values");
+    }
+
+    @Test
+    public void testDisallowedEmptyMixedTensor() {
+        TensorType type = TensorType.fromSpec("tensor(x{},y[3])");
+        assertDecodeFails(type, "{\"blocks\":{ \"a\": [] } }", "The 'block' value array does not contain any values");
+        assertDecodeFails(type, "{\"blocks\":[ {\"address\":{\"x\":\"a\"}, \"values\": [] } ] }",
+                "The 'block' value array does not contain any values");
+    }
+
+    @Test
     public void testDenseTensorInDenseForm() {
         Tensor.Builder builder = Tensor.Builder.of(TensorType.fromSpec("tensor(x[2],y[3])"));
         builder.cell().label("x", 0).label("y", 0).value(2.0);
@@ -304,4 +319,13 @@ public class JsonFormatTestCase {
         assertEquals(expected, new String(json, StandardCharsets.UTF_8));
     }
 
+    private void assertDecodeFails(TensorType type, String format, String msg) {
+        try {
+            Tensor decoded = JsonFormat.decode(type, format.getBytes(StandardCharsets.UTF_8));
+            fail("Did not get exception as expected, decoded as: " + decoded);
+        } catch (IllegalArgumentException e) {
+            assertEquals(e.getMessage(), msg);
+        }
+    }
+
 }