Ejemplo n.º 1
0
// CheckByteLayout verifies the bytes of a Builder in various scenarios.
func CheckByteLayout(fail func(string, ...interface{})) {
	var b *flatbuffers.Builder

	var i int
	check := func(want []byte) {
		i++
		got := b.Bytes[b.Head():]
		if !bytes.Equal(want, got) {
			fail("case %d: want\n%v\nbut got\n%v\n", i, want, got)
		}
	}

	// test 1: numbers

	b = flatbuffers.NewBuilder(0)
	check([]byte{})
	b.PrependBool(true)
	check([]byte{1})
	b.PrependInt8(-127)
	check([]byte{129, 1})
	b.PrependUint8(255)
	check([]byte{255, 129, 1})
	b.PrependInt16(-32222)
	check([]byte{0x22, 0x82, 0, 255, 129, 1}) // first pad
	b.PrependUint16(0xFEEE)
	check([]byte{0xEE, 0xFE, 0x22, 0x82, 0, 255, 129, 1}) // no pad this time
	b.PrependInt32(-53687092)
	check([]byte{204, 204, 204, 252, 0xEE, 0xFE, 0x22, 0x82, 0, 255, 129, 1})
	b.PrependUint32(0x98765432)
	check([]byte{0x32, 0x54, 0x76, 0x98, 204, 204, 204, 252, 0xEE, 0xFE, 0x22, 0x82, 0, 255, 129, 1})

	// test 1b: numbers 2

	b = flatbuffers.NewBuilder(0)
	b.PrependUint64(0x1122334455667788)
	check([]byte{0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11})

	// test 2: 1xbyte vector

	b = flatbuffers.NewBuilder(0)
	check([]byte{})
	b.StartVector(flatbuffers.SizeByte, 1, 1)
	check([]byte{0, 0, 0}) // align to 4bytes
	b.PrependByte(1)
	check([]byte{1, 0, 0, 0})
	b.EndVector(1)
	check([]byte{1, 0, 0, 0, 1, 0, 0, 0}) // padding

	// test 3: 2xbyte vector

	b = flatbuffers.NewBuilder(0)
	b.StartVector(flatbuffers.SizeByte, 2, 1)
	check([]byte{0, 0}) // align to 4bytes
	b.PrependByte(1)
	check([]byte{1, 0, 0})
	b.PrependByte(2)
	check([]byte{2, 1, 0, 0})
	b.EndVector(2)
	check([]byte{2, 0, 0, 0, 2, 1, 0, 0}) // padding

	// test 3b: 11xbyte vector matches builder size

	b = flatbuffers.NewBuilder(12)
	b.StartVector(flatbuffers.SizeByte, 8, 1)
	start := []byte{}
	check(start)
	for i := 1; i < 12; i++ {
		b.PrependByte(byte(i))
		start = append([]byte{byte(i)}, start...)
		check(start)
	}
	b.EndVector(8)
	check(append([]byte{8, 0, 0, 0}, start...))

	// test 4: 1xuint16 vector

	b = flatbuffers.NewBuilder(0)
	b.StartVector(flatbuffers.SizeUint16, 1, 1)
	check([]byte{0, 0}) // align to 4bytes
	b.PrependUint16(1)
	check([]byte{1, 0, 0, 0})
	b.EndVector(1)
	check([]byte{1, 0, 0, 0, 1, 0, 0, 0}) // padding

	// test 5: 2xuint16 vector

	b = flatbuffers.NewBuilder(0)
	b.StartVector(flatbuffers.SizeUint16, 2, 1)
	check([]byte{}) // align to 4bytes
	b.PrependUint16(0xABCD)
	check([]byte{0xCD, 0xAB})
	b.PrependUint16(0xDCBA)
	check([]byte{0xBA, 0xDC, 0xCD, 0xAB})
	b.EndVector(2)
	check([]byte{2, 0, 0, 0, 0xBA, 0xDC, 0xCD, 0xAB})

	// test 6: CreateString

	b = flatbuffers.NewBuilder(0)
	b.CreateString("foo")
	check([]byte{3, 0, 0, 0, 'f', 'o', 'o', 0}) // 0-terminated, no pad
	b.CreateString("moop")
	check([]byte{4, 0, 0, 0, 'm', 'o', 'o', 'p', 0, 0, 0, 0, // 0-terminated, 3-byte pad
		3, 0, 0, 0, 'f', 'o', 'o', 0})

	// test 6b: CreateString unicode

	b = flatbuffers.NewBuilder(0)
	// These characters are chinese from blog.golang.org/strings
	// We use escape codes here so that editors without unicode support
	// aren't bothered:
	uni_str := "\u65e5\u672c\u8a9e"
	b.CreateString(uni_str)
	check([]byte{9, 0, 0, 0, 230, 151, 165, 230, 156, 172, 232, 170, 158, 0, //  null-terminated, 2-byte pad
		0, 0})

	// test 6c: CreateByteString

	b = flatbuffers.NewBuilder(0)
	b.CreateByteString([]byte("foo"))
	check([]byte{3, 0, 0, 0, 'f', 'o', 'o', 0}) // 0-terminated, no pad
	b.CreateByteString([]byte("moop"))
	check([]byte{4, 0, 0, 0, 'm', 'o', 'o', 'p', 0, 0, 0, 0, // 0-terminated, 3-byte pad
		3, 0, 0, 0, 'f', 'o', 'o', 0})

	// test 7: empty vtable
	b = flatbuffers.NewBuilder(0)
	b.StartObject(0)
	check([]byte{})
	b.EndObject()
	check([]byte{4, 0, 4, 0, 4, 0, 0, 0})

	// test 8: vtable with one true bool
	b = flatbuffers.NewBuilder(0)
	check([]byte{})
	b.StartObject(1)
	check([]byte{})
	b.PrependBoolSlot(0, true, false)
	b.EndObject()
	check([]byte{
		6, 0, // vtable bytes
		8, 0, // length of object including vtable offset
		7, 0, // start of bool value
		6, 0, 0, 0, // offset for start of vtable (int32)
		0, 0, 0, // padded to 4 bytes
		1, // bool value
	})

	// test 9: vtable with one default bool
	b = flatbuffers.NewBuilder(0)
	check([]byte{})
	b.StartObject(1)
	check([]byte{})
	b.PrependBoolSlot(0, false, false)
	b.EndObject()
	check([]byte{
		6, 0, // vtable bytes
		4, 0, // end of object from here
		0, 0, // entry 1 is zero
		6, 0, 0, 0, // offset for start of vtable (int32)
	})

	// test 10: vtable with one int16
	b = flatbuffers.NewBuilder(0)
	b.StartObject(1)
	b.PrependInt16Slot(0, 0x789A, 0)
	b.EndObject()
	check([]byte{
		6, 0, // vtable bytes
		8, 0, // end of object from here
		6, 0, // offset to value
		6, 0, 0, 0, // offset for start of vtable (int32)
		0, 0, // padding to 4 bytes
		0x9A, 0x78,
	})

	// test 11: vtable with two int16
	b = flatbuffers.NewBuilder(0)
	b.StartObject(2)
	b.PrependInt16Slot(0, 0x3456, 0)
	b.PrependInt16Slot(1, 0x789A, 0)
	b.EndObject()
	check([]byte{
		8, 0, // vtable bytes
		8, 0, // end of object from here
		6, 0, // offset to value 0
		4, 0, // offset to value 1
		8, 0, 0, 0, // offset for start of vtable (int32)
		0x9A, 0x78, // value 1
		0x56, 0x34, // value 0
	})

	// test 12: vtable with int16 and bool
	b = flatbuffers.NewBuilder(0)
	b.StartObject(2)
	b.PrependInt16Slot(0, 0x3456, 0)
	b.PrependBoolSlot(1, true, false)
	b.EndObject()
	check([]byte{
		8, 0, // vtable bytes
		8, 0, // end of object from here
		6, 0, // offset to value 0
		5, 0, // offset to value 1
		8, 0, 0, 0, // offset for start of vtable (int32)
		0,          // padding
		1,          // value 1
		0x56, 0x34, // value 0
	})

	// test 12: vtable with empty vector
	b = flatbuffers.NewBuilder(0)
	b.StartVector(flatbuffers.SizeByte, 0, 1)
	vecend := b.EndVector(0)
	b.StartObject(1)
	b.PrependUOffsetTSlot(0, vecend, 0)
	b.EndObject()
	check([]byte{
		6, 0, // vtable bytes
		8, 0,
		4, 0, // offset to vector offset
		6, 0, 0, 0, // offset for start of vtable (int32)
		4, 0, 0, 0,
		0, 0, 0, 0, // length of vector (not in struct)
	})

	// test 12b: vtable with empty vector of byte and some scalars
	b = flatbuffers.NewBuilder(0)
	b.StartVector(flatbuffers.SizeByte, 0, 1)
	vecend = b.EndVector(0)
	b.StartObject(2)
	b.PrependInt16Slot(0, 55, 0)
	b.PrependUOffsetTSlot(1, vecend, 0)
	b.EndObject()
	check([]byte{
		8, 0, // vtable bytes
		12, 0,
		10, 0, // offset to value 0
		4, 0, // offset to vector offset
		8, 0, 0, 0, // vtable loc
		8, 0, 0, 0, // value 1
		0, 0, 55, 0, // value 0

		0, 0, 0, 0, // length of vector (not in struct)
	})

	// test 13: vtable with 1 int16 and 2-vector of int16
	b = flatbuffers.NewBuilder(0)
	b.StartVector(flatbuffers.SizeInt16, 2, 1)
	b.PrependInt16(0x1234)
	b.PrependInt16(0x5678)
	vecend = b.EndVector(2)
	b.StartObject(2)
	b.PrependUOffsetTSlot(1, vecend, 0)
	b.PrependInt16Slot(0, 55, 0)
	b.EndObject()
	check([]byte{
		8, 0, // vtable bytes
		12, 0, // length of object
		6, 0, // start of value 0 from end of vtable
		8, 0, // start of value 1 from end of buffer
		8, 0, 0, 0, // offset for start of vtable (int32)
		0, 0, // padding
		55, 0, // value 0
		4, 0, 0, 0, // vector position from here
		2, 0, 0, 0, // length of vector (uint32)
		0x78, 0x56, // vector value 1
		0x34, 0x12, // vector value 0
	})

	// test 14: vtable with 1 struct of 1 int8, 1 int16, 1 int32
	b = flatbuffers.NewBuilder(0)
	b.StartObject(1)
	b.Prep(4+4+4, 0)
	b.PrependInt8(55)
	b.Pad(3)
	b.PrependInt16(0x1234)
	b.Pad(2)
	b.PrependInt32(0x12345678)
	structStart := b.Offset()
	b.PrependStructSlot(0, structStart, 0)
	b.EndObject()
	check([]byte{
		6, 0, // vtable bytes
		16, 0, // end of object from here
		4, 0, // start of struct from here
		6, 0, 0, 0, // offset for start of vtable (int32)
		0x78, 0x56, 0x34, 0x12, // value 2
		0, 0, // padding
		0x34, 0x12, // value 1
		0, 0, 0, // padding
		55, // value 0
	})

	// test 15: vtable with 1 vector of 2 struct of 2 int8
	b = flatbuffers.NewBuilder(0)
	b.StartVector(flatbuffers.SizeInt8*2, 2, 1)
	b.PrependInt8(33)
	b.PrependInt8(44)
	b.PrependInt8(55)
	b.PrependInt8(66)
	vecend = b.EndVector(2)
	b.StartObject(1)
	b.PrependUOffsetTSlot(0, vecend, 0)
	b.EndObject()
	check([]byte{
		6, 0, // vtable bytes
		8, 0,
		4, 0, // offset of vector offset
		6, 0, 0, 0, // offset for start of vtable (int32)
		4, 0, 0, 0, // vector start offset

		2, 0, 0, 0, // vector length
		66, // vector value 1,1
		55, // vector value 1,0
		44, // vector value 0,1
		33, // vector value 0,0
	})

	// test 16: table with some elements
	b = flatbuffers.NewBuilder(0)
	b.StartObject(2)
	b.PrependInt8Slot(0, 33, 0)
	b.PrependInt16Slot(1, 66, 0)
	off := b.EndObject()
	b.Finish(off)

	check([]byte{
		12, 0, 0, 0, // root of table: points to vtable offset

		8, 0, // vtable bytes
		8, 0, // end of object from here
		7, 0, // start of value 0
		4, 0, // start of value 1

		8, 0, 0, 0, // offset for start of vtable (int32)

		66, 0, // value 1
		0,  // padding
		33, // value 0
	})

	// test 17: one unfinished table and one finished table
	b = flatbuffers.NewBuilder(0)
	b.StartObject(2)
	b.PrependInt8Slot(0, 33, 0)
	b.PrependInt8Slot(1, 44, 0)
	off = b.EndObject()
	b.Finish(off)

	b.StartObject(3)
	b.PrependInt8Slot(0, 55, 0)
	b.PrependInt8Slot(1, 66, 0)
	b.PrependInt8Slot(2, 77, 0)
	off = b.EndObject()
	b.Finish(off)

	check([]byte{
		16, 0, 0, 0, // root of table: points to object
		0, 0, // padding

		10, 0, // vtable bytes
		8, 0, // size of object
		7, 0, // start of value 0
		6, 0, // start of value 1
		5, 0, // start of value 2
		10, 0, 0, 0, // offset for start of vtable (int32)
		0,  // padding
		77, // value 2
		66, // value 1
		55, // value 0

		12, 0, 0, 0, // root of table: points to object

		8, 0, // vtable bytes
		8, 0, // size of object
		7, 0, // start of value 0
		6, 0, // start of value 1
		8, 0, 0, 0, // offset for start of vtable (int32)
		0, 0, // padding
		44, // value 1
		33, // value 0
	})

	// test 18: a bunch of bools
	b = flatbuffers.NewBuilder(0)
	b.StartObject(8)
	b.PrependBoolSlot(0, true, false)
	b.PrependBoolSlot(1, true, false)
	b.PrependBoolSlot(2, true, false)
	b.PrependBoolSlot(3, true, false)
	b.PrependBoolSlot(4, true, false)
	b.PrependBoolSlot(5, true, false)
	b.PrependBoolSlot(6, true, false)
	b.PrependBoolSlot(7, true, false)
	off = b.EndObject()
	b.Finish(off)

	check([]byte{
		24, 0, 0, 0, // root of table: points to vtable offset

		20, 0, // vtable bytes
		12, 0, // size of object
		11, 0, // start of value 0
		10, 0, // start of value 1
		9, 0, // start of value 2
		8, 0, // start of value 3
		7, 0, // start of value 4
		6, 0, // start of value 5
		5, 0, // start of value 6
		4, 0, // start of value 7
		20, 0, 0, 0, // vtable offset

		1, // value 7
		1, // value 6
		1, // value 5
		1, // value 4
		1, // value 3
		1, // value 2
		1, // value 1
		1, // value 0
	})

	// test 19: three bools
	b = flatbuffers.NewBuilder(0)
	b.StartObject(3)
	b.PrependBoolSlot(0, true, false)
	b.PrependBoolSlot(1, true, false)
	b.PrependBoolSlot(2, true, false)
	off = b.EndObject()
	b.Finish(off)

	check([]byte{
		16, 0, 0, 0, // root of table: points to vtable offset

		0, 0, // padding

		10, 0, // vtable bytes
		8, 0, // size of object
		7, 0, // start of value 0
		6, 0, // start of value 1
		5, 0, // start of value 2
		10, 0, 0, 0, // vtable offset from here

		0, // padding
		1, // value 2
		1, // value 1
		1, // value 0
	})

	// test 20: some floats
	b = flatbuffers.NewBuilder(0)
	b.StartObject(1)
	b.PrependFloat32Slot(0, 1.0, 0.0)
	off = b.EndObject()

	check([]byte{
		6, 0, // vtable bytes
		8, 0, // size of object
		4, 0, // start of value 0
		6, 0, 0, 0, // vtable offset

		0, 0, 128, 63, // value 0
	})
}
Ejemplo n.º 2
0
func MonsterAddPos(builder *flatbuffers.Builder, pos flatbuffers.UOffsetT) {
	builder.PrependStructSlot(0, flatbuffers.UOffsetT(pos), 0)
}
Ejemplo n.º 3
0
func TableInFirstNSAddFooStruct(builder *flatbuffers.Builder, fooStruct flatbuffers.UOffsetT) {
	builder.PrependStructSlot(2, flatbuffers.UOffsetT(fooStruct), 0)
}