Fix encoder without string column

client/src/main/java/com/vesoft/nebula/encoder/RowWriterImpl.java

@@ -82,7 +82,7 @@ public RowWriterImpl(SchemaProviderImpl schema, ByteOrder byteOrder) throws Runt
         if (numNullables > 0) {
             numNullBytes = ((numNullables - 1) >> 3) + 1;
         }
-        buf = ByteBuffer.allocate(headerLen + numNullBytes + schema.size());
+        buf = ByteBuffer.allocate(headerLen + numNullBytes + schema.size() + Long.BYTES);
         buf.order(this.byteOrder);
         buf.put(header);
         if (ver > 0) {
@@ -767,9 +767,9 @@ public ByteBuffer processOutOfSpace() {
 
         // Reserve enough space to avoid memory re-allocation
         // Copy the data except the strings
-        temp = temp.put(buf.array());
+        temp = temp.put(buf.array(), 0, buf.array().length - Long.BYTES);
 
-        int strOffset = buf.array().length;
+        int strOffset = buf.array().length - Long.BYTES;
 
         // Now let's process all strings
         int strNum = 0;
@@ -812,7 +812,7 @@ public void finish() {
             buf = processOutOfSpace();
         }
         // Save the timestamp to the tail of buf
-        buf.putLong(getTimestamp());
+        buf.putLong(buf.array().length - Long.BYTES, getTimestamp());
     }
 
     private long getTimestamp() {

client/src/test/java/com/vesoft/nebula/encoder/MetaCacheImplTest.java

@@ -158,6 +158,14 @@ public Schema genEmptyString() {
         return new Schema(columns, null);
     }
 
+    public Schema genWithoutString() {
+        List<ColumnDef> columns = new ArrayList<>();
+        ColumnDef columnDef = new ColumnDef(("Col01").getBytes(),
+            new ColumnTypeDef(PropertyType.INT64));
+        columns.add(columnDef);
+        return new Schema(columns, null);
+    }
+
     public MetaCacheImplTest() {
         spaceItem.space_id = 1;
         SpaceDesc spaceDesc = new SpaceDesc("test_space".getBytes(),
@@ -190,6 +198,12 @@ public MetaCacheImplTest() {
         tagItem3.schema = genEmptyString();
         this.tagItems.put(new String(tagItem3.tag_name), tagItem3);
 
+        TagItem tagItem4 = new TagItem();
+        tagItem4.tag_name = "tag_without_string".getBytes();
+        tagItem4.version = 7;
+        tagItem4.schema = genWithoutString();
+        this.tagItems.put(new String(tagItem4.tag_name), tagItem4);
+
         EdgeItem edgeItem1 = new EdgeItem();
         edgeItem1.edge_name = "edge_no_default".getBytes();
         edgeItem1.schema = genNoDefaultVal();

client/src/test/java/com/vesoft/nebula/encoder/TestEncoder.java

@@ -210,6 +210,7 @@ public void testEncodeVertexValue() {
         TagItem tagItem1 = cacheImplTest.getTag("test", "tag_no_default");
         TagItem tagItem2 = cacheImplTest.getTag("test", "tag_with_empty_string");
         TagItem tagItem3 = cacheImplTest.getTag("test", "tag_with_default");
+        TagItem tagItem4 = cacheImplTest.getTag("test", "tag_without_string");
         try {
             codec.encodeTag(tagItem1, colNames, colVals);
             Assert.fail();
@@ -253,6 +254,19 @@ public void testEncodeVertexValue() {
                 "Unsupported default value yet".getBytes());
             assert (true);
         }
+
+        // test without string type
+        try {
+            byte[] encodeStr = codec.encodeTag(
+                tagItem4, Arrays.asList("Col01"), Arrays.asList(1024));
+            String hexStr = Hex.encodeHexString(encodeStr);
+            String expectResult = "09070004000000000000";
+            Assert.assertArrayEquals(expectResult.getBytes(),
+                hexStr.substring(0, hexStr.length() - 16).getBytes());
+        } catch (Exception exception) {
+            exception.printStackTrace();
+            Assert.fail(exception.getMessage());
+        }
     }
 
     @Test()