From 8b99bf614c3b91e3fa79e8b225bff7e6f03ca7f2 Mon Sep 17 00:00:00 2001
From: Ben Harper <rogojin@gmail.com>
Date: Wed, 1 Apr 2015 16:39:53 +0200
Subject: [PATCH] Add byte slice accessor to Go code

Change-Id: I15cc8924d6607bd93068c762fd67e6088cfd9789
---
 go/table.go                     |  7 ++++++-
 src/idl_gen_go.cpp              | 16 ++++++++++++++++
 tests/MyGame/Example/Monster.go | 18 ++++++++++++++++++
 tests/go_test.go                |  8 ++++++++
 4 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/go/table.go b/go/table.go
index dc5c399..695b92d 100644
--- a/go/table.go
+++ b/go/table.go
@@ -26,10 +26,15 @@ func (t *Table) Indirect(off UOffsetT) UOffsetT {
 
 // String gets a string from data stored inside the flatbuffer.
 func (t *Table) String(off UOffsetT) string {
+	return string(t.ByteVector(off))
+}
+
+// ByteVector gets a byte slice from data stored inside the flatbuffer.
+func (t *Table) ByteVector(off UOffsetT) []byte {
 	off += GetUOffsetT(t.Bytes[off:])
 	start := off + UOffsetT(SizeUOffsetT)
 	length := GetUOffsetT(t.Bytes[off:])
-	return string(t.Bytes[start : start+length])
+	return t.Bytes[start : start+length]
 }
 
 // VectorLen retrieves the length of the vector whose offset is stored at
diff --git a/src/idl_gen_go.cpp b/src/idl_gen_go.cpp
index b509439..9cbaf99 100644
--- a/src/idl_gen_go.cpp
+++ b/src/idl_gen_go.cpp
@@ -144,6 +144,19 @@ static void GetVectorLen(const StructDef &struct_def,
   code += "\treturn 0\n}\n\n";
 }
 
+// Get a [ubyte] vector as a byte slice.
+static void GetUByteSlice(const StructDef &struct_def,
+                          const FieldDef &field,
+                          std::string *code_ptr) {
+  std::string &code = *code_ptr;
+
+  GenReceiver(struct_def, code_ptr);
+  code += " " + MakeCamel(field.name) + "Bytes(";
+  code += ") []byte " + OffsetPrefix(field);
+  code += "\t\treturn rcv._tab.ByteVector(o + rcv._tab.Pos)\n\t}\n";
+  code += "\treturn nil\n}\n\n";
+}
+
 // Get the value of a struct's scalar.
 static void GetScalarFieldOfStruct(const StructDef &struct_def,
                                    const FieldDef &field,
@@ -480,6 +493,9 @@ static void GenStructAccessor(const StructDef &struct_def,
   }
   if (field.value.type.base_type == BASE_TYPE_VECTOR) {
     GetVectorLen(struct_def, field, code_ptr);
+    if (field.value.type.element == BASE_TYPE_UCHAR) {
+      GetUByteSlice(struct_def, field, code_ptr);
+    }
   }
 }
 
diff --git a/tests/MyGame/Example/Monster.go b/tests/MyGame/Example/Monster.go
index 1abb902..0ca0c80 100644
--- a/tests/MyGame/Example/Monster.go
+++ b/tests/MyGame/Example/Monster.go
@@ -75,6 +75,14 @@ func (rcv *Monster) InventoryLength() int {
 	return 0
 }
 
+func (rcv *Monster) InventoryBytes() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(14))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
 func (rcv *Monster) Color() int8 {
 	o := flatbuffers.UOffsetT(rcv._tab.Offset(16))
 	if o != 0 {
@@ -140,7 +148,9 @@ func (rcv *Monster) TestarrayofstringLength() int {
 }
 
 /// an example documentation comment: this will end up in the generated code
+
 /// multiline too
+
 func (rcv *Monster) Testarrayoftables(obj *Monster, j int) bool {
 	o := flatbuffers.UOffsetT(rcv._tab.Offset(26))
 	if o != 0 {
@@ -194,6 +204,14 @@ func (rcv *Monster) TestnestedflatbufferLength() int {
 	return 0
 }
 
+func (rcv *Monster) TestnestedflatbufferBytes() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(30))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
 func (rcv *Monster) Testempty(obj *Stat) *Stat {
 	o := flatbuffers.UOffsetT(rcv._tab.Offset(32))
 	if o != 0 {
diff --git a/tests/go_test.go b/tests/go_test.go
index 492b896..08e823c 100644
--- a/tests/go_test.go
+++ b/tests/go_test.go
@@ -214,6 +214,11 @@ func CheckReadBuffer(buf []byte, offset flatbuffers.UOffsetT, fail func(string,
 		fail(FailString("monster2.Name()", "Fred", got))
 	}
 
+	inventorySlice := monster.InventoryBytes()
+	if len(inventorySlice) != monster.InventoryLength() {
+		fail(FailString("len(monster.InventoryBytes) != monster.InventoryLength", len(inventorySlice), monster.InventoryLength()))
+	}
+
 	if got := monster.InventoryLength(); 5 != got {
 		fail(FailString("monster.InventoryLength", 5, got))
 	}
@@ -222,6 +227,9 @@ func CheckReadBuffer(buf []byte, offset flatbuffers.UOffsetT, fail func(string,
 	l := monster.InventoryLength()
 	for i := 0; i < l; i++ {
 		v := monster.Inventory(i)
+		if v != inventorySlice[i] {
+			fail(FailString("monster inventory slice[i] != Inventory(i)", v, inventorySlice[i]))
+		}
 		invsum += int(v)
 	}
 	if invsum != 10 {
-- 
2.7.4