Merge pull request #363 from danring/fix-341

Emit GetRootAs methods for all types in Go and Python

tests/MyGame/Example/Monster.py

@@ -15,7 +15,6 @@ class Monster(object):
         x.Init(buf, n + offset)
         return x
 
-
     # Monster
     def Init(self, buf, pos):
         self._tab = flatbuffers.table.Table(buf, pos)

tests/MyGame/Example/Stat.go

@@ -9,6 +9,13 @@ type Stat struct {
 	_tab flatbuffers.Table
 }
 
+func GetRootAsStat(buf []byte, offset flatbuffers.UOffsetT) *Stat {
+	n := flatbuffers.GetUOffsetT(buf[offset:])
+	x := &Stat{}
+	x.Init(buf, n + offset)
+	return x
+}
+
 func (rcv *Stat) Init(buf []byte, i flatbuffers.UOffsetT) {
 	rcv._tab.Bytes = buf
 	rcv._tab.Pos = i

tests/MyGame/Example/Stat.py

@@ -7,6 +7,13 @@ import flatbuffers
 class Stat(object):
     __slots__ = ['_tab']
 
+    @classmethod
+    def GetRootAsStat(cls, buf, offset):
+        n = flatbuffers.encode.Get(flatbuffers.packer.uoffset, buf, offset)
+        x = Stat()
+        x.Init(buf, n + offset)
+        return x
+
     # Stat
     def Init(self, buf, pos):
         self._tab = flatbuffers.table.Table(buf, pos)

tests/MyGame/Example/TestSimpleTableWithEnum.go

@@ -9,6 +9,13 @@ type TestSimpleTableWithEnum struct {
 	_tab flatbuffers.Table
 }
 
+func GetRootAsTestSimpleTableWithEnum(buf []byte, offset flatbuffers.UOffsetT) *TestSimpleTableWithEnum {
+	n := flatbuffers.GetUOffsetT(buf[offset:])
+	x := &TestSimpleTableWithEnum{}
+	x.Init(buf, n + offset)
+	return x
+}
+
 func (rcv *TestSimpleTableWithEnum) Init(buf []byte, i flatbuffers.UOffsetT) {
 	rcv._tab.Bytes = buf
 	rcv._tab.Pos = i

tests/MyGame/Example/TestSimpleTableWithEnum.py

@@ -7,6 +7,13 @@ import flatbuffers
 class TestSimpleTableWithEnum(object):
     __slots__ = ['_tab']
 
+    @classmethod
+    def GetRootAsTestSimpleTableWithEnum(cls, buf, offset):
+        n = flatbuffers.encode.Get(flatbuffers.packer.uoffset, buf, offset)
+        x = TestSimpleTableWithEnum()
+        x.Init(buf, n + offset)
+        return x
+
     # TestSimpleTableWithEnum
     def Init(self, buf, pos):
         self._tab = flatbuffers.table.Table(buf, pos)

tests/go_test.go

@@ -76,6 +76,9 @@ func TestAll(t *testing.T) {
 	CheckStructIsNotInlineError(t.Fatalf)
 	CheckFinishedBytesError(t.Fatalf)
 
+	// Verify that GetRootAs works for non-root tables
+	CheckGetRootAsForNonRootTable(t.Fatalf)
+
 	// Verify that using the generated Go code builds a buffer without
 	// returning errors:
 	generated, off := CheckGeneratedBuild(t.Fatalf)
@@ -1081,6 +1084,31 @@ func CheckManualBuild(fail func(string, ...interface{})) ([]byte, flatbuffers.UO
 	return b.Bytes, b.Head()
 }
 
+func CheckGetRootAsForNonRootTable(fail func(string, ...interface{})) {
+	b := flatbuffers.NewBuilder(0)
+	str := b.CreateString("MyStat")
+	example.StatStart(b)
+	example.StatAddId(b, str)
+	example.StatAddVal(b, 12345678)
+	example.StatAddCount(b, 12345)
+	stat_end := example.StatEnd(b)
+	b.Finish(stat_end)
+
+	stat := example.GetRootAsStat(b.Bytes, b.Head())
+
+	if got := stat.Id(); !bytes.Equal([]byte("MyStat"), got) {
+		fail(FailString("stat.Id()", "MyStat", got))
+	}
+
+	if got := stat.Val(); 12345678 != got {
+		fail(FailString("stat.Val()", 12345678, got))
+	}
+
+	if got := stat.Count(); 12345 != got {
+		fail(FailString("stat.Count()", 12345, got))
+	}
+}
+
 // CheckGeneratedBuild uses generated code to build the example Monster.
 func CheckGeneratedBuild(fail func(string, ...interface{})) ([]byte, flatbuffers.UOffsetT) {
 	b := flatbuffers.NewBuilder(0)

tests/py_test.py

@@ -1034,6 +1034,23 @@ class TestAllCodePathsOfExampleSchema(unittest.TestCase):
         self.assertEqual(7, mon2.Testhashs64Fnv1a())
         self.assertEqual(8, mon2.Testhashu64Fnv1a())
 
+    def test_getrootas_for_nonroot_table(self):
+        b = flatbuffers.Builder(0)
+        string = b.CreateString("MyStat")
+
+        MyGame.Example.Stat.StatStart(b)
+        MyGame.Example.Stat.StatAddId(b, string)
+        MyGame.Example.Stat.StatAddVal(b, 12345678)
+        MyGame.Example.Stat.StatAddCount(b, 12345)
+        stat = MyGame.Example.Stat.StatEnd(b)
+        b.Finish(stat)
+
+        stat2 = MyGame.Example.Stat.Stat.GetRootAsStat(b.Bytes, b.Head())
+
+        self.assertEqual(b"MyStat", stat2.Id())
+        self.assertEqual(12345678, stat2.Val())
+        self.assertEqual(12345, stat2.Count())
+
 
 class TestVtableDeduplication(unittest.TestCase):
     ''' TestVtableDeduplication verifies that vtables are deduplicated. '''