mirror of
https://github.com/golang/go.git
synced 2025-12-08 06:10:04 +00:00
change the encoding of uints to simplify overflow checking and to make them
easier and faster to read. they are now either a one-byte value or a n-byte value preceded by a byte holding -n. R=rsc DELTA=150 (45 added, 7 deleted, 98 changed) OCL=32381 CL=32387
This commit is contained in:
Rob Pike
parent
189153ed13
commit
b85147cd70
7 changed files with 137 additions and 99 deletions
|
|
@ -21,20 +21,20 @@ type EncodeT struct {
|
|||
b []byte;
|
||||
}
|
||||
var encodeT = []EncodeT {
|
||||
EncodeT{ 0x00, []byte{0x80} },
|
||||
EncodeT{ 0x0f, []byte{0x8f} },
|
||||
EncodeT{ 0xff, []byte{0x7f, 0x81} },
|
||||
EncodeT{ 0xffff, []byte{0x7f, 0x7f, 0x83} },
|
||||
EncodeT{ 0xffffff, []byte{0x7f, 0x7f, 0x7f, 0x87} },
|
||||
EncodeT{ 0xffffffff, []byte{0x7f, 0x7f, 0x7f, 0x7f, 0x8f} },
|
||||
EncodeT{ 0xffffffffff, []byte{0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x9f} },
|
||||
EncodeT{ 0xffffffffffff, []byte{0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0xbf} },
|
||||
EncodeT{ 0xffffffffffffff, []byte{0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0xff} },
|
||||
EncodeT{ 0xffffffffffffffff, []byte{0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x81} },
|
||||
EncodeT{ 0x1111, []byte{0x11, 0xa2} },
|
||||
EncodeT{ 0x1111111111111111, []byte{0x11, 0x22, 0x44, 0x08, 0x11, 0x22, 0x44, 0x08, 0x91} },
|
||||
EncodeT{ 0x8888888888888888, []byte{0x08, 0x11, 0x22, 0x44, 0x08, 0x11, 0x22, 0x44, 0x08, 0x81} },
|
||||
EncodeT{ 1<<63, []byte{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x81} },
|
||||
EncodeT{ 0x00, []byte{0x00} },
|
||||
EncodeT{ 0x0F, []byte{0x0F} },
|
||||
EncodeT{ 0xFF, []byte{0xFF, 0xFF} },
|
||||
EncodeT{ 0xFFFF, []byte{0xFE, 0xFF, 0xFF} },
|
||||
EncodeT{ 0xFFFFFF, []byte{0xFD, 0xFF, 0xFF, 0xFF} },
|
||||
EncodeT{ 0xFFFFFFFF, []byte{0xFC, 0xFF, 0xFF, 0xFF, 0xFF} },
|
||||
EncodeT{ 0xFFFFFFFFFF, []byte{0xFB, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF} },
|
||||
EncodeT{ 0xFFFFFFFFFFFF, []byte{0xFA, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF} },
|
||||
EncodeT{ 0xFFFFFFFFFFFFFF, []byte{0xF9, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF} },
|
||||
EncodeT{ 0xFFFFFFFFFFFFFFFF, []byte{0xF8, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF} },
|
||||
EncodeT{ 0x1111, []byte{0xFE, 0x11, 0x11} },
|
||||
EncodeT{ 0x1111111111111111, []byte{0xF8, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11} },
|
||||
EncodeT{ 0x8888888888888888, []byte{0xF8, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88} },
|
||||
EncodeT{ 1<<63, []byte{0xF8, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00} },
|
||||
}
|
||||
|
||||
|
||||
|
|
@ -50,11 +50,10 @@ func TestUintCodec(t *testing.T) {
|
|||
t.Error("encodeUint:", tt.x, encState.err)
|
||||
}
|
||||
if !bytes.Equal(tt.b, b.Data()) {
|
||||
t.Errorf("encodeUint: expected % x got % x", tt.b, b.Data())
|
||||
t.Errorf("encodeUint: %#x encode: expected % x got % x", tt.x, tt.b, b.Data())
|
||||
}
|
||||
}
|
||||
decState := new(decodeState);
|
||||
decState.b = b;
|
||||
decState := newDecodeState(b);
|
||||
for u := uint64(0); ; u = (u+1) * 7 {
|
||||
b.Reset();
|
||||
encodeUint(encState, u);
|
||||
|
|
@ -82,8 +81,8 @@ func verifyInt(i int64, t *testing.T) {
|
|||
if encState.err != nil {
|
||||
t.Error("encodeInt:", i, encState.err)
|
||||
}
|
||||
decState := new(decodeState);
|
||||
decState.b = b;
|
||||
decState := newDecodeState(b);
|
||||
decState.buf = make([]byte, 8);
|
||||
j := decodeInt(decState);
|
||||
if decState.err != nil {
|
||||
t.Error("DecodeInt:", i, decState.err)
|
||||
|
|
@ -109,14 +108,14 @@ func TestIntCodec(t *testing.T) {
|
|||
verifyInt(-1<<63, t); // a tricky case
|
||||
}
|
||||
|
||||
// The result of encoding a true boolean with field number 6
|
||||
var boolResult = []byte{0x87, 0x81}
|
||||
// The result of encoding a number 17 with field number 6
|
||||
var signedResult = []byte{0x87, 0xa2}
|
||||
var unsignedResult = []byte{0x87, 0x91}
|
||||
var floatResult = []byte{0x87, 0x40, 0xe2}
|
||||
// The result of encoding a true boolean with field number 7
|
||||
var boolResult = []byte{0x07, 0x01}
|
||||
// The result of encoding a number 17 with field number 7
|
||||
var signedResult = []byte{0x07, 2*17}
|
||||
var unsignedResult = []byte{0x07, 17}
|
||||
var floatResult = []byte{0x07, 0xFE, 0x31, 0x40}
|
||||
// The result of encoding "hello" with field number 6
|
||||
var bytesResult = []byte{0x87, 0x85, 'h', 'e', 'l', 'l', 'o'}
|
||||
var bytesResult = []byte{0x07, 0x05, 'h', 'e', 'l', 'l', 'o'}
|
||||
|
||||
func newencoderState(b *bytes.Buffer) *encoderState {
|
||||
b.Reset();
|
||||
|
|
@ -338,9 +337,8 @@ func execDec(typ string, instr *decInstr, state *decodeState, t *testing.T, p un
|
|||
state.fieldnum = 6;
|
||||
}
|
||||
|
||||
func newdecodeState(data []byte) *decodeState {
|
||||
state := new(decodeState);
|
||||
state.b = bytes.NewBuffer(data);
|
||||
func newDecodeStateFromData(data []byte) *decodeState {
|
||||
state := newDecodeState(bytes.NewBuffer(data));
|
||||
state.fieldnum = -1;
|
||||
return state;
|
||||
}
|
||||
|
|
@ -354,7 +352,7 @@ func TestScalarDecInstructions(t *testing.T) {
|
|||
{
|
||||
var data struct { a bool };
|
||||
instr := &decInstr{ decBool, 6, 0, 0, ovfl };
|
||||
state := newdecodeState(boolResult);
|
||||
state := newDecodeStateFromData(boolResult);
|
||||
execDec("bool", instr, state, t, unsafe.Pointer(&data));
|
||||
if data.a != true {
|
||||
t.Errorf("bool a = %v not true", data.a)
|
||||
|
|
@ -364,7 +362,7 @@ func TestScalarDecInstructions(t *testing.T) {
|
|||
{
|
||||
var data struct { a int };
|
||||
instr := &decInstr{ decOpMap[valueKind(data.a)], 6, 0, 0, ovfl };
|
||||
state := newdecodeState(signedResult);
|
||||
state := newDecodeStateFromData(signedResult);
|
||||
execDec("int", instr, state, t, unsafe.Pointer(&data));
|
||||
if data.a != 17 {
|
||||
t.Errorf("int a = %v not 17", data.a)
|
||||
|
|
@ -375,7 +373,7 @@ func TestScalarDecInstructions(t *testing.T) {
|
|||
{
|
||||
var data struct { a uint };
|
||||
instr := &decInstr{ decOpMap[valueKind(data.a)], 6, 0, 0, ovfl };
|
||||
state := newdecodeState(unsignedResult);
|
||||
state := newDecodeStateFromData(unsignedResult);
|
||||
execDec("uint", instr, state, t, unsafe.Pointer(&data));
|
||||
if data.a != 17 {
|
||||
t.Errorf("uint a = %v not 17", data.a)
|
||||
|
|
@ -386,7 +384,7 @@ func TestScalarDecInstructions(t *testing.T) {
|
|||
{
|
||||
var data struct { a int8 };
|
||||
instr := &decInstr{ decInt8, 6, 0, 0, ovfl };
|
||||
state := newdecodeState(signedResult);
|
||||
state := newDecodeStateFromData(signedResult);
|
||||
execDec("int8", instr, state, t, unsafe.Pointer(&data));
|
||||
if data.a != 17 {
|
||||
t.Errorf("int8 a = %v not 17", data.a)
|
||||
|
|
@ -397,7 +395,7 @@ func TestScalarDecInstructions(t *testing.T) {
|
|||
{
|
||||
var data struct { a uint8 };
|
||||
instr := &decInstr{ decUint8, 6, 0, 0, ovfl };
|
||||
state := newdecodeState(unsignedResult);
|
||||
state := newDecodeStateFromData(unsignedResult);
|
||||
execDec("uint8", instr, state, t, unsafe.Pointer(&data));
|
||||
if data.a != 17 {
|
||||
t.Errorf("uint8 a = %v not 17", data.a)
|
||||
|
|
@ -408,7 +406,7 @@ func TestScalarDecInstructions(t *testing.T) {
|
|||
{
|
||||
var data struct { a int16 };
|
||||
instr := &decInstr{ decInt16, 6, 0, 0, ovfl };
|
||||
state := newdecodeState(signedResult);
|
||||
state := newDecodeStateFromData(signedResult);
|
||||
execDec("int16", instr, state, t, unsafe.Pointer(&data));
|
||||
if data.a != 17 {
|
||||
t.Errorf("int16 a = %v not 17", data.a)
|
||||
|
|
@ -419,7 +417,7 @@ func TestScalarDecInstructions(t *testing.T) {
|
|||
{
|
||||
var data struct { a uint16 };
|
||||
instr := &decInstr{ decUint16, 6, 0, 0, ovfl };
|
||||
state := newdecodeState(unsignedResult);
|
||||
state := newDecodeStateFromData(unsignedResult);
|
||||
execDec("uint16", instr, state, t, unsafe.Pointer(&data));
|
||||
if data.a != 17 {
|
||||
t.Errorf("uint16 a = %v not 17", data.a)
|
||||
|
|
@ -430,7 +428,7 @@ func TestScalarDecInstructions(t *testing.T) {
|
|||
{
|
||||
var data struct { a int32 };
|
||||
instr := &decInstr{ decInt32, 6, 0, 0, ovfl };
|
||||
state := newdecodeState(signedResult);
|
||||
state := newDecodeStateFromData(signedResult);
|
||||
execDec("int32", instr, state, t, unsafe.Pointer(&data));
|
||||
if data.a != 17 {
|
||||
t.Errorf("int32 a = %v not 17", data.a)
|
||||
|
|
@ -441,7 +439,7 @@ func TestScalarDecInstructions(t *testing.T) {
|
|||
{
|
||||
var data struct { a uint32 };
|
||||
instr := &decInstr{ decUint32, 6, 0, 0, ovfl };
|
||||
state := newdecodeState(unsignedResult);
|
||||
state := newDecodeStateFromData(unsignedResult);
|
||||
execDec("uint32", instr, state, t, unsafe.Pointer(&data));
|
||||
if data.a != 17 {
|
||||
t.Errorf("uint32 a = %v not 17", data.a)
|
||||
|
|
@ -452,7 +450,7 @@ func TestScalarDecInstructions(t *testing.T) {
|
|||
{
|
||||
var data struct { a uintptr };
|
||||
instr := &decInstr{ decOpMap[valueKind(data.a)], 6, 0, 0, ovfl };
|
||||
state := newdecodeState(unsignedResult);
|
||||
state := newDecodeStateFromData(unsignedResult);
|
||||
execDec("uintptr", instr, state, t, unsafe.Pointer(&data));
|
||||
if data.a != 17 {
|
||||
t.Errorf("uintptr a = %v not 17", data.a)
|
||||
|
|
@ -463,7 +461,7 @@ func TestScalarDecInstructions(t *testing.T) {
|
|||
{
|
||||
var data struct { a int64 };
|
||||
instr := &decInstr{ decInt64, 6, 0, 0, ovfl };
|
||||
state := newdecodeState(signedResult);
|
||||
state := newDecodeStateFromData(signedResult);
|
||||
execDec("int64", instr, state, t, unsafe.Pointer(&data));
|
||||
if data.a != 17 {
|
||||
t.Errorf("int64 a = %v not 17", data.a)
|
||||
|
|
@ -474,7 +472,7 @@ func TestScalarDecInstructions(t *testing.T) {
|
|||
{
|
||||
var data struct { a uint64 };
|
||||
instr := &decInstr{ decUint64, 6, 0, 0, ovfl };
|
||||
state := newdecodeState(unsignedResult);
|
||||
state := newDecodeStateFromData(unsignedResult);
|
||||
execDec("uint64", instr, state, t, unsafe.Pointer(&data));
|
||||
if data.a != 17 {
|
||||
t.Errorf("uint64 a = %v not 17", data.a)
|
||||
|
|
@ -485,7 +483,7 @@ func TestScalarDecInstructions(t *testing.T) {
|
|||
{
|
||||
var data struct { a float };
|
||||
instr := &decInstr{ decOpMap[valueKind(data.a)], 6, 0, 0, ovfl };
|
||||
state := newdecodeState(floatResult);
|
||||
state := newDecodeStateFromData(floatResult);
|
||||
execDec("float", instr, state, t, unsafe.Pointer(&data));
|
||||
if data.a != 17 {
|
||||
t.Errorf("float a = %v not 17", data.a)
|
||||
|
|
@ -496,7 +494,7 @@ func TestScalarDecInstructions(t *testing.T) {
|
|||
{
|
||||
var data struct { a float32 };
|
||||
instr := &decInstr{ decFloat32, 6, 0, 0, ovfl };
|
||||
state := newdecodeState(floatResult);
|
||||
state := newDecodeStateFromData(floatResult);
|
||||
execDec("float32", instr, state, t, unsafe.Pointer(&data));
|
||||
if data.a != 17 {
|
||||
t.Errorf("float32 a = %v not 17", data.a)
|
||||
|
|
@ -507,7 +505,7 @@ func TestScalarDecInstructions(t *testing.T) {
|
|||
{
|
||||
var data struct { a float64 };
|
||||
instr := &decInstr{ decFloat64, 6, 0, 0, ovfl };
|
||||
state := newdecodeState(floatResult);
|
||||
state := newDecodeStateFromData(floatResult);
|
||||
execDec("float64", instr, state, t, unsafe.Pointer(&data));
|
||||
if data.a != 17 {
|
||||
t.Errorf("float64 a = %v not 17", data.a)
|
||||
|
|
@ -518,7 +516,7 @@ func TestScalarDecInstructions(t *testing.T) {
|
|||
{
|
||||
var data struct { a []byte };
|
||||
instr := &decInstr{ decUint8Array, 6, 0, 0, ovfl };
|
||||
state := newdecodeState(bytesResult);
|
||||
state := newDecodeStateFromData(bytesResult);
|
||||
execDec("bytes", instr, state, t, unsafe.Pointer(&data));
|
||||
if string(data.a) != "hello" {
|
||||
t.Errorf(`bytes a = %q not "hello"`, string(data.a))
|
||||
|
|
@ -529,7 +527,7 @@ func TestScalarDecInstructions(t *testing.T) {
|
|||
{
|
||||
var data struct { a string };
|
||||
instr := &decInstr{ decString, 6, 0, 0, ovfl };
|
||||
state := newdecodeState(bytesResult);
|
||||
state := newDecodeStateFromData(bytesResult);
|
||||
execDec("bytes", instr, state, t, unsafe.Pointer(&data));
|
||||
if data.a != "hello" {
|
||||
t.Errorf(`bytes a = %q not "hello"`, data.a)
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue