Golang go.NewBuilder函数代码示例

func makeNoticeMsg(str string, p uint16) []byte {
	t := transport.TcpMessage{}

	builder := flatbuffers.NewBuilder(0)

	ct := builder.CreateString(str)
	proto.NoticeStart(builder)
	proto.NoticeAddContent(builder, ct)
	payload := proto.NoticeEnd(builder)

	builder.Finish(payload)

	t.Payload = builder.Bytes[builder.Head():]

	// 填充协议头信息
	t.Header.Proto = p
	t.Header.Flag = 0xdcba
	t.Header.Size = uint16(len(t.Payload))

	ret, err := t.Pack()
	if err != nil {
		log.Fatal(err.Error())
		return nil
	}
	return ret
}

func ToAndFromFlat(uids []uint64) (error, int) {
	b := flatbuffers.NewBuilder(0)
	fuids.UidListStartUidsVector(b, len(uids))
	for i := len(uids) - 1; i >= 0; i-- {
		b.PrependUint64(uids[i])
	}
	ve := b.EndVector(len(uids))
	fuids.UidListStart(b)
	fuids.UidListAddUids(b, ve)
	ue := fuids.UidListEnd(b)
	b.Finish(ue)
	data := b.FinishedBytes()

	nl := fuids.GetRootAsUidList(data, 0)
	if nl.UidsLength() != len(uids) {
		return fmt.Errorf("Length doesn't match"), 0
	}
	for i := 0; i < len(uids); i++ {
		if nl.Uids(i) != uids[i] {
			return fmt.Errorf("ID doesn't match at index: %v Expected: %v. Got: %v",
				i, uids[i], nl.Uids(i)), 0
		}
	}

	return nil, len(data)
}

// BenchmarkVtableDeduplication measures the speed of vtable deduplication
// by creating prePop vtables, then populating b.N objects with a
// different single vtable.
//
// When b.N is large (as in long benchmarks), memory usage may be high.
func BenchmarkVtableDeduplication(b *testing.B) {
	prePop := 10
	builder := flatbuffers.NewBuilder(0)

	// pre-populate some vtables:
	for i := 0; i < prePop; i++ {
		builder.StartObject(i)
		for j := 0; j < i; j++ {
			builder.PrependInt16Slot(j, int16(j), 0)
		}
		builder.EndObject()
	}

	// benchmark deduplication of a new vtable:
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		lim := prePop

		builder.StartObject(lim)
		for j := 0; j < lim; j++ {
			builder.PrependInt16Slot(j, int16(j), 0)
		}
		builder.EndObject()
	}
}

// BenchmarkBuildGold uses generated code to build the example Monster.
func BenchmarkBuildGold(b *testing.B) {
	buf, offset := CheckGeneratedBuild(b.Fatalf)
	bytes_length := int64(len(buf[offset:]))

	reuse_str := "MyMonster"
	reuse_test1 := "test1"
	reuse_test2 := "test2"
	reuse_fred := "Fred"

	b.SetBytes(bytes_length)
	bldr := flatbuffers.NewBuilder(0)
	b.ResetTimer()
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		bldr.Reset()

		str := bldr.CreateString(reuse_str)
		test1 := bldr.CreateString(reuse_test1)
		test2 := bldr.CreateString(reuse_test2)
		fred := bldr.CreateString(reuse_fred)

		example.MonsterStartInventoryVector(bldr, 5)
		bldr.PrependByte(4)
		bldr.PrependByte(3)
		bldr.PrependByte(2)
		bldr.PrependByte(1)
		bldr.PrependByte(0)
		inv := bldr.EndVector(5)

		example.MonsterStart(bldr)
		example.MonsterAddName(bldr, fred)
		mon2 := example.MonsterEnd(bldr)

		example.MonsterStartTest4Vector(bldr, 2)
		example.CreateTest(bldr, 10, 20)
		example.CreateTest(bldr, 30, 40)
		test4 := bldr.EndVector(2)

		example.MonsterStartTestarrayofstringVector(bldr, 2)
		bldr.PrependUOffsetT(test2)
		bldr.PrependUOffsetT(test1)
		testArrayOfString := bldr.EndVector(2)

		example.MonsterStart(bldr)

		pos := example.CreateVec3(bldr, 1.0, 2.0, 3.0, 3.0, 2, 5, 6)
		example.MonsterAddPos(bldr, pos)

		example.MonsterAddHp(bldr, 80)
		example.MonsterAddName(bldr, str)
		example.MonsterAddInventory(bldr, inv)
		example.MonsterAddTestType(bldr, 1)
		example.MonsterAddTest(bldr, mon2)
		example.MonsterAddTest4(bldr, test4)
		example.MonsterAddTestarrayofstring(bldr, testArrayOfString)
		mon := example.MonsterEnd(bldr)

		bldr.Finish(mon)
	}
}

func BenchmarkFlatBuffersUnmarshal(b *testing.B) {
	b.StopTimer()
	builder := flatbuffers.NewBuilder(0)
	data := generate()
	ser := make([][]byte, len(data))
	for i, d := range data {
		ser[i] = serializeUsingFlatBuffers(builder, d)
	}

	b.ReportAllocs()
	b.StartTimer()
	for i := 0; i < b.N; i++ {
		n := rand.Intn(len(ser))
		o := FlatBufferA{}
		sData := ser[n]
		o.Init(sData, flatbuffers.GetUOffsetT(sData))
		if validate != "" {
			i := data[n]
			spouseVal := o.Spouse() == byte(1)

			correct := o.Name() == i.Name &&
				o.Phone() == i.Phone &&
				int(o.Siblings()) == i.Siblings &&
				spouseVal == i.Spouse &&
				o.Money() == i.Money &&
				o.BirthDay() == i.BirthDay.Unix()
			if !correct {
				b.Fatalf("unmarshaled object differed:\n%v\n%v", i, o)
			}
		}
	}
}

// CheckDocExample checks that the code given in FlatBuffers documentation
// is syntactically correct.
func CheckDocExample(buf []byte, off flatbuffers.UOffsetT, fail func(string, ...interface{})) {
	monster := example.GetRootAsMonster(buf, off)
	_ = monster.Hp()
	_ = monster.Pos(nil)
	for i := 0; i < monster.InventoryLength(); i++ {
		_ = monster.Inventory(i) // do something here
	}

	builder := flatbuffers.NewBuilder(0)

	example.MonsterStartInventoryVector(builder, 5)
	for i := 4; i >= 0; i-- {
		builder.PrependByte(byte(i))
	}
	inv := builder.EndVector(5)

	str := builder.CreateString("MyMonster")
	example.MonsterStart(builder)
	example.MonsterAddPos(builder, example.CreateVec3(builder, 1.0, 2.0, 3.0, 3.0, 4, 5, 6))
	example.MonsterAddHp(builder, 80)
	example.MonsterAddName(builder, str)
	example.MonsterAddInventory(builder, inv)
	example.MonsterAddTestType(builder, 1)
	// example.MonsterAddTest(builder, mon2)
	// example.MonsterAddTest4(builder, test4s)
	_ = example.MonsterEnd(builder)
}

func BenchmarkMarshalByFlatBuffers(b *testing.B) {
	builder := flatbuffers.NewBuilder(0)
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		serializeByFlatBuffers(builder, &group)
	}
}

func BenchmarkUnmarshalByFlatBuffers(b *testing.B) {
	builder := flatbuffers.NewBuilder(0)
	bytes := serializeByFlatBuffers(builder, &group)
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_ = GetRootAsFlatBufferColorGroup(bytes, 0)
	}
}

func main() {
	builder := flatbuffers.NewBuilder(0)
	buf := MakeMonster(builder)

	monster := example.GetRootAsMonster(buf, 0)
	monster_name := monster.Name()

	fmt.Printf("Monster named '%s' encoded in %d bytes.\n", monster_name, len(buf))
}

func CheckCreateByteVector(fail func(string, ...interface{})) {
	raw := [30]byte{}
	for i := 0; i < len(raw); i++ {
		raw[i] = byte(i)
	}

	for size := 0; size < len(raw); size++ {
		b1 := flatbuffers.NewBuilder(0)
		b2 := flatbuffers.NewBuilder(0)
		b1.StartVector(1, size, 1)
		for i := size - 1; i >= 0; i-- {
			b1.PrependByte(raw[i])
		}
		b1.EndVector(size)
		b2.CreateByteVector(raw[:size])
		CheckByteEquality(b1.Bytes, b2.Bytes, fail)
	}
}

func BenchmarkWrite(b *testing.B) {
	builder := flatbuffers.NewBuilder(0)
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		builder.Reset()
		buf := MakeUser(builder, []byte("Arthur Dent"), 42)
		if i == 0 {
			b.SetBytes(int64(len(buf)))
		}
	}
}

// CheckStructIsNotInlineError verifies that writing a struct in a location
// away from where it is used will cause a panic.
func CheckStructIsNotInlineError(fail func(string, ...interface{})) {
	b := flatbuffers.NewBuilder(0)
	b.StartObject(0)
	defer func() {
		r := recover()
		if r == nil {
			fail("expected panic in CheckStructIsNotInlineError")
		}
	}()
	b.PrependStructSlot(0, 1, 0)
}

// CheckFinishedBytesError verifies that `FinishedBytes` panics if the table
// is not finished.
func CheckFinishedBytesError(fail func(string, ...interface{})) {
	b := flatbuffers.NewBuilder(0)

	defer func() {
		r := recover()
		if r == nil {
			fail("expected panic in CheckFinishedBytesError")
		}
	}()
	b.FinishedBytes()
}

func BenchmarkFlatbuffersMarshal(b *testing.B) {
	b.StopTimer()
	data := generate()
	builder := flatbuffers.NewBuilder(0)
	b.ReportAllocs()
	b.StartTimer()

	for i := 0; i < b.N; i++ {
		serializeUsingFlatBuffers(builder, data[rand.Intn(len(data))])
	}
}

// CheckByteStringIsNestedError verifies that a bytestring can not be created
// inside another object.
func CheckByteStringIsNestedError(fail func(string, ...interface{})) {
	b := flatbuffers.NewBuilder(0)
	b.StartObject(0)
	defer func() {
		r := recover()
		if r == nil {
			fail("expected panic in CheckByteStringIsNestedError")
		}
	}()
	b.CreateByteString([]byte("foo"))
}