Skip to content

G
go
Commit f6f82514 authored by Rob Pike's avatar Rob Pike
Browse files
Options

encoders for booleans and numbers. 

R=rsc
DELTA=610  (597 added, 5 deleted, 8 changed)
OCL=30934
CL=30939
parent 832e72be
Hide whitespace changes
Inline Side-by-side
Showing with 605 additions and 13 deletions
src/pkg/gob/codec_test.go
View file @ f6f82514
......@@ -9,6 +9,7 @@ import (
"gob";
"os";
"testing";
"unsafe";
)
// Guarantee encoding format by comparing some encodings to hand-written values
......@@ -95,3 +96,354 @@ func TestIntCodec(t *testing.T) {
}
verifyInt(-1<<63, t); // a tricky case
}
// The result of encoding three true booleans with field numbers 0, 1, 2
var boolResult = []byte{0x80, 0x81, 0x81, 0x81, 0x82, 0x81}
// The result of encoding three numbers = 17 with field numbers 0, 1, 2
var signedResult = []byte{0x80, 0xa2, 0x81, 0xa2, 0x82, 0xa2}
var unsignedResult = []byte{0x80, 0x91, 0x81, 0x91, 0x82, 0x91}
var floatResult = []byte{0x80, 0x40, 0xe2, 0x81, 0x40, 0xe2, 0x82, 0x40, 0xe2}
// Test instruction execution for encoding.
// Do not run the machine yet; instead do individual instructions crafted by hand.
func TestScalarEncInstructions(t *testing.T) {
var b = new(bytes.Buffer);
var state encState;
// bool
{
b.Reset();
v := true;
pv := &v;
ppv := &pv;
data := (struct { a bool; b *bool; c **bool }){ v, pv, ppv };
instr := &encInstr{ encBool, 0, 0, 0 };
state.w = b;
state.base = uintptr(unsafe.Pointer(&data));
instr.op(instr, &state);
instr.field = 1;
instr.indir = 1;
instr.offset = uintptr(unsafe.Offsetof(data.b));
instr.op(instr, &state);
instr.field = 2;
instr.indir = 2;
instr.offset = uintptr(unsafe.Offsetof(data.c));
instr.op(instr, &state);
if !bytes.Equal(boolResult, b.Data()) {
t.Errorf("bool enc instructions: expected % x got % x", boolResult, b.Data())
}
}
// int
{
b.Reset();
v := 17;
pv := &v;
ppv := &pv;
data := (struct { a int; b *int; c **int }){ v, pv, ppv };
instr := &encInstr{ encInt, 0, 0, 0 };
state.w = b;
state.base = uintptr(unsafe.Pointer(&data));
instr.op(instr, &state);
instr.field = 1;
instr.indir = 1;
instr.offset = uintptr(unsafe.Offsetof(data.b));
instr.op(instr, &state);
instr.field = 2;
instr.indir = 2;
instr.offset = uintptr(unsafe.Offsetof(data.c));
instr.op(instr, &state);
if !bytes.Equal(signedResult, b.Data()) {
t.Errorf("int enc instructions: expected % x got % x", signedResult, b.Data())
}
}
// uint
{
b.Reset();
v := uint(17);
pv := &v;
ppv := &pv;
data := (struct { a uint; b *uint; c **uint }){ v, pv, ppv };
instr := &encInstr{ encUint, 0, 0, 0 };
state.w = b;
state.base = uintptr(unsafe.Pointer(&data));
instr.op(instr, &state);
instr.field = 1;
instr.indir = 1;
instr.offset = uintptr(unsafe.Offsetof(data.b));
instr.op(instr, &state);
instr.field = 2;
instr.indir = 2;
instr.offset = uintptr(unsafe.Offsetof(data.c));
instr.op(instr, &state);
if !bytes.Equal(unsignedResult, b.Data()) {
t.Errorf("uint enc instructions: expected % x got % x", unsignedResult, b.Data())
}
}
// int8
{
b.Reset();
v := int8(17);
pv := &v;
ppv := &pv;
data := (struct { a int8; b *int8; c **int8 }){ v, pv, ppv };
instr := &encInstr{ encInt, 0, 0, 0 };
state.w = b;
state.base = uintptr(unsafe.Pointer(&data));
instr.op(instr, &state);
instr.field = 1;
instr.indir = 1;
instr.offset = uintptr(unsafe.Offsetof(data.b));
instr.op(instr, &state);
instr.field = 2;
instr.indir = 2;
instr.offset = uintptr(unsafe.Offsetof(data.c));
instr.op(instr, &state);
if !bytes.Equal(signedResult, b.Data()) {
t.Errorf("int8 enc instructions: expected % x got % x", signedResult, b.Data())
}
}
// uint8
{
b.Reset();
v := uint8(17);
pv := &v;
ppv := &pv;
data := (struct { a uint8; b *uint8; c **uint8 }){ v, pv, ppv };
instr := &encInstr{ encUint, 0, 0, 0 };
state.w = b;
state.base = uintptr(unsafe.Pointer(&data));
instr.op(instr, &state);
instr.field = 1;
instr.indir = 1;
instr.offset = uintptr(unsafe.Offsetof(data.b));
instr.op(instr, &state);
instr.field = 2;
instr.indir = 2;
instr.offset = uintptr(unsafe.Offsetof(data.c));
instr.op(instr, &state);
if !bytes.Equal(unsignedResult, b.Data()) {
t.Errorf("uint8 enc instructions: expected % x got % x", unsignedResult, b.Data())
}
}
// int16
{
b.Reset();
v := int16(17);
pv := &v;
ppv := &pv;
data := (struct { a int16; b *int16; c **int16 }){ v, pv, ppv };
instr := &encInstr{ encInt16, 0, 0, 0 };
state.w = b;
state.base = uintptr(unsafe.Pointer(&data));
instr.op(instr, &state);
instr.field = 1;
instr.indir = 1;
instr.offset = uintptr(unsafe.Offsetof(data.b));
instr.op(instr, &state);
instr.field = 2;
instr.indir = 2;
instr.offset = uintptr(unsafe.Offsetof(data.c));
instr.op(instr, &state);
if !bytes.Equal(signedResult, b.Data()) {
t.Errorf("int16 enc instructions: expected % x got % x", signedResult, b.Data())
}
}
// uint16
{
b.Reset();
v := uint16(17);
pv := &v;
ppv := &pv;
data := (struct { a uint16; b *uint16; c **uint16 }){ v, pv, ppv };
instr := &encInstr{ encUint16, 0, 0, 0 };
state.w = b;
state.base = uintptr(unsafe.Pointer(&data));
instr.op(instr, &state);
instr.field = 1;
instr.indir = 1;
instr.offset = uintptr(unsafe.Offsetof(data.b));
instr.op(instr, &state);
instr.field = 2;
instr.indir = 2;
instr.offset = uintptr(unsafe.Offsetof(data.c));
instr.op(instr, &state);
if !bytes.Equal(unsignedResult, b.Data()) {
t.Errorf("uint16 enc instructions: expected % x got % x", unsignedResult, b.Data())
}
}
// int32
{
b.Reset();
v := int32(17);
pv := &v;
ppv := &pv;
data := (struct { a int32; b *int32; c **int32 }){ v, pv, ppv };
instr := &encInstr{ encInt32, 0, 0, 0 };
state.w = b;
state.base = uintptr(unsafe.Pointer(&data));
instr.op(instr, &state);
instr.field = 1;
instr.indir = 1;
instr.offset = uintptr(unsafe.Offsetof(data.b));
instr.op(instr, &state);
instr.field = 2;
instr.indir = 2;
instr.offset = uintptr(unsafe.Offsetof(data.c));
instr.op(instr, &state);
if !bytes.Equal(signedResult, b.Data()) {
t.Errorf("int32 enc instructions: expected % x got % x", signedResult, b.Data())
}
}
// uint32
{
b.Reset();
v := uint32(17);
pv := &v;
ppv := &pv;
data := (struct { a uint32; b *uint32; c **uint32 }){ v, pv, ppv };
instr := &encInstr{ encUint32, 0, 0, 0 };
state.w = b;
state.base = uintptr(unsafe.Pointer(&data));
instr.op(instr, &state);
instr.field = 1;
instr.indir = 1;
instr.offset = uintptr(unsafe.Offsetof(data.b));
instr.op(instr, &state);
instr.field = 2;
instr.indir = 2;
instr.offset = uintptr(unsafe.Offsetof(data.c));
instr.op(instr, &state);
if !bytes.Equal(unsignedResult, b.Data()) {
t.Errorf("uint32 enc instructions: expected % x got % x", unsignedResult, b.Data())
}
}
// int64
{
b.Reset();
v := int64(17);
pv := &v;
ppv := &pv;
data := (struct { a int64; b *int64; c **int64 }){ v, pv, ppv };
instr := &encInstr{ encInt64, 0, 0, 0 };
state.w = b;
state.base = uintptr(unsafe.Pointer(&data));
instr.op(instr, &state);
instr.field = 1;
instr.indir = 1;
instr.offset = uintptr(unsafe.Offsetof(data.b));
instr.op(instr, &state);
instr.field = 2;
instr.indir = 2;
instr.offset = uintptr(unsafe.Offsetof(data.c));
instr.op(instr, &state);
if !bytes.Equal(signedResult, b.Data()) {
t.Errorf("int64 enc instructions: expected % x got % x", signedResult, b.Data())
}
}
// uint64
{
b.Reset();
v := uint64(17);
pv := &v;
ppv := &pv;
data := (struct { a uint64; b *uint64; c **uint64 }){ v, pv, ppv };
instr := &encInstr{ encUint, 0, 0, 0 };
state.w = b;
state.base = uintptr(unsafe.Pointer(&data));
instr.op(instr, &state);
instr.field = 1;
instr.indir = 1;
instr.offset = uintptr(unsafe.Offsetof(data.b));
instr.op(instr, &state);
instr.field = 2;
instr.indir = 2;
instr.offset = uintptr(unsafe.Offsetof(data.c));
instr.op(instr, &state);
if !bytes.Equal(unsignedResult, b.Data()) {
t.Errorf("uint64 enc instructions: expected % x got % x", unsignedResult, b.Data())
}
}
// float
{
b.Reset();
v := float(17);
pv := &v;
ppv := &pv;
data := (struct { a float; b *float; c **float }){ v, pv, ppv };
instr := &encInstr{ encFloat, 0, 0, 0 };
state.w = b;
state.base = uintptr(unsafe.Pointer(&data));
instr.op(instr, &state);
instr.field = 1;
instr.indir = 1;
instr.offset = uintptr(unsafe.Offsetof(data.b));
instr.op(instr, &state);
instr.field = 2;
instr.indir = 2;
instr.offset = uintptr(unsafe.Offsetof(data.c));
instr.op(instr, &state);
if !bytes.Equal(floatResult, b.Data()) {
t.Errorf("float enc instructions: expected % x got % x", floatResult, b.Data())
}
}
// float32
{
b.Reset();
v := float32(17);
pv := &v;
ppv := &pv;
data := (struct { a float32; b *float32; c **float32 }){ v, pv, ppv };
instr := &encInstr{ encFloat32, 0, 0, 0 };
state.w = b;
state.base = uintptr(unsafe.Pointer(&data));
instr.op(instr, &state);
instr.field = 1;
instr.indir = 1;
instr.offset = uintptr(unsafe.Offsetof(data.b));
instr.op(instr, &state);
instr.field = 2;
instr.indir = 2;
instr.offset = uintptr(unsafe.Offsetof(data.c));
instr.op(instr, &state);
if !bytes.Equal(floatResult, b.Data()) {
t.Errorf("float32 enc instructions: expected % x got % x", floatResult, b.Data())
}
}
// float64
{
b.Reset();
v := float64(17);
pv := &v;
ppv := &pv;
data := (struct { a float64; b *float64; c **float64 }){ v, pv, ppv };
instr := &encInstr{ encFloat64, 0, 0, 0 };
state.w = b;
state.base = uintptr(unsafe.Pointer(&data));
instr.op(instr, &state);
instr.field = 1;
instr.indir = 1;
instr.offset = uintptr(unsafe.Offsetof(data.b));
instr.op(instr, &state);
instr.field = 2;
instr.indir = 2;
instr.offset = uintptr(unsafe.Offsetof(data.c));
instr.op(instr, &state);
if !bytes.Equal(floatResult, b.Data()) {
t.Errorf("float64 enc instructions: expected % x got % x", floatResult, b.Data())
}
}
}
src/pkg/gob/encode.go
View file @ f6f82514
......@@ -6,7 +6,9 @@ package gob
import (
"io";
"math";
"os";
"unsafe";
)
// Integers encode as a variant of Google's protocol buffer varint (varvarint?).
......@@ -38,3 +40,246 @@ func EncodeInt(w io.Writer, i int64) os.Error {
}
return EncodeUint(w, uint64(x))
}
// The global execution state of an instance of the encoder.
type encState struct {
w io.Writer;
base uintptr;
}
// The 'instructions' of the encoding machine
type encInstr struct {
op func(i *encInstr, state *encState);
field int; // field number
indir int; // how many pointer indirections to reach the value in the struct
offset uintptr; // offset in the structure of the field to encode
}
func encBool(i *encInstr, state *encState) {
p := unsafe.Pointer(state.base+i.offset);
for indir := i.indir; indir > 0; indir-- {
p = *(*unsafe.Pointer)(p);
if p == nil {
return
}
}
b := *(*bool)(p);
if b {
EncodeUint(state.w, uint64(i.field));
EncodeUint(state.w, 1);
}
}
func encInt(i *encInstr, state *encState) {
p := unsafe.Pointer(state.base+i.offset);
for indir := i.indir; indir > 0; indir-- {
p = *(*unsafe.Pointer)(p);
if p == nil {
return
}
}
v := int64(*(*int)(p));
if v != 0 {
EncodeUint(state.w, uint64(i.field));
EncodeInt(state.w, v);
}
}
func encUint(i *encInstr, state *encState) {
p := unsafe.Pointer(state.base+i.offset);
for indir := i.indir; indir > 0; indir-- {
p = *(*unsafe.Pointer)(p);
if p == nil {
return
}
}
v := uint64(*(*uint)(p));
if v != 0 {
EncodeUint(state.w, uint64(i.field));
EncodeUint(state.w, v);
}
}
func encInt8(i *encInstr, state *encState) {
p := unsafe.Pointer(state.base+i.offset);
for indir := i.indir; indir > 0; indir-- {
p = *(*unsafe.Pointer)(p);
if p == nil {
return
}
}
v := int64(*(*int8)(p));
if v != 0 {
EncodeUint(state.w, uint64(i.field));
EncodeInt(state.w, v);
}
}
func encUint8(i *encInstr, state *encState) {
p := unsafe.Pointer(state.base+i.offset);
for indir := i.indir; indir > 0; indir-- {
p = *(*unsafe.Pointer)(p);
if p == nil {
return
}
}
v := uint64(*(*uint8)(p));
if v != 0 {
EncodeUint(state.w, uint64(i.field));
EncodeUint(state.w, v);
}
}
func encInt16(i *encInstr, state *encState) {
p := unsafe.Pointer(state.base+i.offset);
for indir := i.indir; indir > 0; indir-- {
p = *(*unsafe.Pointer)(p);
if p == nil {
return
}
}
v := int64(*(*int16)(p));
if v != 0 {
EncodeUint(state.w, uint64(i.field));
EncodeInt(state.w, v);
}
}
func encUint16(i *encInstr, state *encState) {
p := unsafe.Pointer(state.base+i.offset);
for indir := i.indir; indir > 0; indir-- {
p = *(*unsafe.Pointer)(p);
if p == nil {
return
}
}
v := uint64(*(*uint16)(p));
if v != 0 {
EncodeUint(state.w, uint64(i.field));
EncodeUint(state.w, v);
}
}
func encInt32(i *encInstr, state *encState) {
p := unsafe.Pointer(state.base+i.offset);
for indir := i.indir; indir > 0; indir-- {
p = *(*unsafe.Pointer)(p);
if p == nil {
return
}
}
v := int64(*(*int32)(p));
if v != 0 {
EncodeUint(state.w, uint64(i.field));
EncodeInt(state.w, v);
}
}
func encUint32(i *encInstr, state *encState) {
p := unsafe.Pointer(state.base+i.offset);
for indir := i.indir; indir > 0; indir-- {
p = *(*unsafe.Pointer)(p);
if p == nil {
return
}
}
v := uint64(*(*uint32)(p));
if v != 0 {
EncodeUint(state.w, uint64(i.field));
EncodeUint(state.w, v);
}
}
func encInt64(i *encInstr, state *encState) {
p := unsafe.Pointer(state.base+i.offset);
for indir := i.indir; indir > 0; indir-- {
p = *(*unsafe.Pointer)(p);
if p == nil {
return
}
}
v := *(*int64)(p);
if v != 0 {
EncodeUint(state.w, uint64(i.field));
EncodeInt(state.w, v);
}
}
func encUint64(i *encInstr, state *encState) {
p := unsafe.Pointer(state.base+i.offset);
for indir := i.indir; indir > 0; indir-- {
p = *(*unsafe.Pointer)(p);
if p == nil {
return
}
}
v := *(*uint64)(p);
if v != 0 {
EncodeUint(state.w, uint64(i.field));
EncodeUint(state.w, v);
}
}
// Floating-point numbers are transmitted as uint64s holding the bits
// of the underlying representation. They are sent byte-reversed, with
// the exponent end coming out first, so integer floating point numbers
// (for example) transmit more compactly. This routine does the
// swizzling.
func floatBits(f float64) uint64 {
u := math.Float64bits(f);
var v uint64;
for i := 0; i < 8; i++ {
v <<= 8;
v |= u & 0xFF;
u >>= 8;
}
return v;
}
func encFloat(i *encInstr, state *encState) {
p := unsafe.Pointer(state.base+i.offset);
for indir := i.indir; indir > 0; indir-- {
p = *(*unsafe.Pointer)(p);
if p == nil {
return
}
}
f := float(*(*float)(p));
if f != 0 {
v := floatBits(float64(f));
EncodeUint(state.w, uint64(i.field));
EncodeUint(state.w, v);
}
}
func encFloat32(i *encInstr, state *encState) {
p := unsafe.Pointer(state.base+i.offset);
for indir := i.indir; indir > 0; indir-- {
p = *(*unsafe.Pointer)(p);
if p == nil {
return
}
}
f := float32(*(*float32)(p));
if f != 0 {
v := floatBits(float64(f));
EncodeUint(state.w, uint64(i.field));
EncodeUint(state.w, v);
}
}
func encFloat64(i *encInstr, state *encState) {
p := unsafe.Pointer(state.base+i.offset);
for indir := i.indir; indir > 0; indir-- {
p = *(*unsafe.Pointer)(p);
if p == nil {
return
}
}
f := *(*float64)(p);
if f != 0 {
v := floatBits(f);
EncodeUint(state.w, uint64(i.field));
EncodeUint(state.w, v);
}
}
src/pkg/gob/type.go
View file @ f6f82514
......@@ -54,8 +54,7 @@ func (t *commonType) Name() string {
var tBool Type
var tInt Type
var tUint Type
var tFloat32 Type
var tFloat64 Type
var tFloat Type
var tString Type
var tBytes Type
......@@ -151,10 +150,8 @@ func newTypeObject(name string, rt reflect.Type) Type {
return tInt
case reflect.UintKind, reflect.Uint32Kind, reflect.Uint64Kind:
return tUint
case reflect.FloatKind, reflect.Float32Kind:
return tFloat32
case reflect.Float64Kind:
return tFloat64
case reflect.FloatKind, reflect.Float32Kind, reflect.Float64Kind:
return tFloat
case reflect.StringKind:
return tString
case reflect.ArrayKind:
......@@ -238,8 +235,7 @@ func init() {
tBool= bootstrapType("bool", false);
tInt = bootstrapType("int", int(0));
tUint = bootstrapType("uint", uint(0));
tFloat32 = bootstrapType("float32", float32(0));
tFloat64 = bootstrapType("float64", float64(0));
tFloat = bootstrapType("float", float64(0));
// The string for tBytes is "bytes" not "[]byte" to signify its specialness.
tBytes = bootstrapType("bytes", make([]byte, 0));
tString= bootstrapType("string", "");
......
src/pkg/gob/type_test.go
View file @ f6f82514
......@@ -18,8 +18,7 @@ var basicTypes = []typeT {
typeT { tBool, "bool" },
typeT { tInt, "int" },
typeT { tUint, "uint" },
typeT { tFloat32, "float32" },
typeT { tFloat64, "float64" },
typeT { tFloat, "float" },
typeT { tBytes, "bytes" },
typeT { tString, "string" },
}
......@@ -107,8 +106,8 @@ type Foo struct {
b int32; // will become int
c string;
d []byte;
e *float; // will become float32
f ****float64; // will become float64
e *float; // will become float
f ****float64; // will become float
g *Bar;
h *Bar; // should not interpolate the definition of Bar again
i *Foo; // will not explode
......@@ -118,7 +117,7 @@ func TestStructType(t *testing.T) {
sstruct := GetType("Foo", Foo{});
str := sstruct.String();
// If we can print it correctly, we built it correctly.
expected := "Foo = struct { a int; b int; c string; d bytes; e float32; f float64; g Bar = struct { x string; }; h Bar; i Foo; }";
expected := "Foo = struct { a int; b int; c string; d bytes; e float; f float; g Bar = struct { x string; }; h Bar; i Foo; }";
if str != expected {
t.Errorf("struct printed as %q; expected %q", str, expected);
}
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7