encode and decode for nested structures.
fix a bug in delta encoding: only update the delta-base if something is marshaled.
R=rsc
DELTA=154 (94 added, 56 deleted, 4 changed)
OCL=31069
CL=31071
diff --git a/src/pkg/gob/codec_test.go b/src/pkg/gob/codec_test.go
index 4b5169e..339774c 100644
--- a/src/pkg/gob/codec_test.go
+++ b/src/pkg/gob/codec_test.go
@@ -569,10 +569,14 @@
func TestEncode(t *testing.T) {
+ type T2 struct {
+ t string
+ }
type T1 struct {
a, b,c int;
s string;
y []byte;
+ t *T2;
}
t1 := &T1{
a: 17,
@@ -580,6 +584,7 @@
c: -5,
s: "Now is the time",
y: strings.Bytes("hello, sailor"),
+ t: &T2{"this is T2"},
};
b := new(bytes.Buffer);
Encode(b, t1);
diff --git a/src/pkg/gob/decode.go b/src/pkg/gob/decode.go
index 79440b2..7a4918a 100644
--- a/src/pkg/gob/decode.go
+++ b/src/pkg/gob/decode.go
@@ -279,6 +279,31 @@
instr []decInstr
}
+func (engine *decEngine) decodeStruct(r io.Reader, p uintptr) os.Error {
+ state := new(DecState);
+ state.r = r;
+ state.base = p;
+ state.fieldnum = -1;
+ for state.err == nil {
+ delta := int(DecodeUint(state));
+ if state.err != nil || delta == 0 { // struct terminator is zero delta fieldnum
+ break
+ }
+ fieldnum := state.fieldnum + delta;
+ if fieldnum >= len(engine.instr) {
+ panicln("TODO(r): need to handle unknown data");
+ }
+ instr := &engine.instr[fieldnum];
+ p := unsafe.Pointer(state.base+instr.offset);
+ if instr.indir > 1 {
+ p = decIndirect(p, instr.indir);
+ }
+ instr.op(instr, state, p);
+ state.fieldnum = fieldnum;
+ }
+ return state.err
+}
+
var decEngineMap = make(map[reflect.Type] *decEngine)
var decOpMap = map[int] decOp {
reflect.BoolKind: decBool,
@@ -298,6 +323,8 @@
reflect.StringKind: decString,
}
+func getDecEngine(rt reflect.Type) *decEngine
+
func decOpFor(typ reflect.Type) decOp {
op, ok := decOpMap[typ.Kind()];
if !ok {
@@ -309,6 +336,13 @@
op = decUint8Array
}
}
+ if typ.Kind() == reflect.StructKind {
+ // Generate a closure that calls out to the engine for the nested type.
+ engine := getDecEngine(typ);
+ op = func(i *decInstr, state *DecState, p unsafe.Pointer) {
+ state.err = engine.decodeStruct(state.r, uintptr(p))
+ };
+ }
}
if op == nil {
panicln("decode can't handle type", typ.String());
@@ -355,35 +389,6 @@
return engine;
}
-func (engine *decEngine) decode(r io.Reader, v reflect.Value) os.Error {
- sv, ok := v.(reflect.StructValue);
- if !ok {
- panicln("decoder can't handle non-struct values yet");
- }
- state := new(DecState);
- state.r = r;
- state.base = uintptr(sv.Addr());
- state.fieldnum = -1;
- for state.err == nil {
- delta := int(DecodeUint(state));
- if state.err != nil || delta == 0 { // struct terminator is zero delta fieldnum
- break
- }
- fieldnum := state.fieldnum + delta;
- if fieldnum >= len(engine.instr) {
- panicln("TODO(r): need to handle unknown data");
- }
- instr := &engine.instr[fieldnum];
- p := unsafe.Pointer(state.base+instr.offset);
- if instr.indir > 1 {
- p = decIndirect(p, instr.indir);
- }
- instr.op(instr, state, p);
- state.fieldnum = fieldnum;
- }
- return state.err
-}
-
func Decode(r io.Reader, e interface{}) os.Error {
// Dereference down to the underlying object.
rt := reflect.Typeof(e);
@@ -396,8 +401,11 @@
rt = pt.Sub();
v = reflect.Indirect(v);
}
+ if v.Kind() != reflect.StructKind {
+ return os.ErrorString("decode can't handle " + v.Type().String())
+ }
typeLock.Lock();
engine := getDecEngine(rt);
typeLock.Unlock();
- return engine.decode(r, v);
+ return engine.decodeStruct(r, uintptr(v.Addr()));
}
diff --git a/src/pkg/gob/encode.go b/src/pkg/gob/encode.go
index e046d6c..a2ff8cb 100644
--- a/src/pkg/gob/encode.go
+++ b/src/pkg/gob/encode.go
@@ -92,6 +92,7 @@
if b {
EncodeUint(state, uint64(i.field - state.fieldnum));
EncodeUint(state, 1);
+ state.fieldnum = i.field;
}
}
@@ -100,6 +101,7 @@
if v != 0 {
EncodeUint(state, uint64(i.field - state.fieldnum));
EncodeInt(state, v);
+ state.fieldnum = i.field;
}
}
@@ -108,6 +110,7 @@
if v != 0 {
EncodeUint(state, uint64(i.field - state.fieldnum));
EncodeUint(state, v);
+ state.fieldnum = i.field;
}
}
@@ -116,6 +119,7 @@
if v != 0 {
EncodeUint(state, uint64(i.field - state.fieldnum));
EncodeInt(state, v);
+ state.fieldnum = i.field;
}
}
@@ -124,6 +128,7 @@
if v != 0 {
EncodeUint(state, uint64(i.field - state.fieldnum));
EncodeUint(state, v);
+ state.fieldnum = i.field;
}
}
@@ -132,6 +137,7 @@
if v != 0 {
EncodeUint(state, uint64(i.field - state.fieldnum));
EncodeInt(state, v);
+ state.fieldnum = i.field;
}
}
@@ -140,6 +146,7 @@
if v != 0 {
EncodeUint(state, uint64(i.field - state.fieldnum));
EncodeUint(state, v);
+ state.fieldnum = i.field;
}
}
@@ -148,6 +155,7 @@
if v != 0 {
EncodeUint(state, uint64(i.field - state.fieldnum));
EncodeInt(state, v);
+ state.fieldnum = i.field;
}
}
@@ -156,6 +164,7 @@
if v != 0 {
EncodeUint(state, uint64(i.field - state.fieldnum));
EncodeUint(state, v);
+ state.fieldnum = i.field;
}
}
@@ -164,6 +173,7 @@
if v != 0 {
EncodeUint(state, uint64(i.field - state.fieldnum));
EncodeInt(state, v);
+ state.fieldnum = i.field;
}
}
@@ -172,6 +182,7 @@
if v != 0 {
EncodeUint(state, uint64(i.field - state.fieldnum));
EncodeUint(state, v);
+ state.fieldnum = i.field;
}
}
@@ -197,6 +208,7 @@
v := floatBits(float64(f));
EncodeUint(state, uint64(i.field - state.fieldnum));
EncodeUint(state, v);
+ state.fieldnum = i.field;
}
}
@@ -206,6 +218,7 @@
v := floatBits(float64(f));
EncodeUint(state, uint64(i.field - state.fieldnum));
EncodeUint(state, v);
+ state.fieldnum = i.field;
}
}
@@ -215,6 +228,7 @@
v := floatBits(f);
EncodeUint(state, uint64(i.field - state.fieldnum));
EncodeUint(state, v);
+ state.fieldnum = i.field;
}
}
@@ -225,6 +239,7 @@
EncodeUint(state, uint64(i.field - state.fieldnum));
EncodeUint(state, uint64(len(b)));
state.w.Write(b);
+ state.fieldnum = i.field;
}
}
@@ -235,6 +250,7 @@
EncodeUint(state, uint64(i.field - state.fieldnum));
EncodeUint(state, uint64(len(s)));
io.WriteString(state.w, s);
+ state.fieldnum = i.field;
}
}
@@ -251,6 +267,28 @@
instr []encInstr
}
+func (engine *encEngine) encodeStruct(w io.Writer, p uintptr) os.Error {
+ state := new(EncState);
+ state.w = w;
+ state.base = p;
+ state.fieldnum = -1;
+ for i := 0; i < len(engine.instr); i++ {
+ instr := &engine.instr[i];
+ p := unsafe.Pointer(state.base+instr.offset);
+ if instr.indir > 0 {
+ if p = encIndirect(p, instr.indir); p == nil {
+ state.fieldnum = i;
+ continue
+ }
+ }
+ instr.op(instr, state, p);
+ if state.err != nil {
+ break
+ }
+ }
+ return state.err
+}
+
var encEngineMap = make(map[reflect.Type] *encEngine)
var encOpMap = map[int] encOp {
reflect.BoolKind: encBool,
@@ -270,6 +308,8 @@
reflect.StringKind: encString,
}
+func getEncEngine(rt reflect.Type) *encEngine
+
func encOpFor(typ reflect.Type) encOp {
op, ok := encOpMap[typ.Kind()];
if !ok {
@@ -281,6 +321,15 @@
op = encUint8Array
}
}
+ if typ.Kind() == reflect.StructKind {
+ // Generate a closure that calls out to the engine for the nested type.
+ engine := getEncEngine(typ);
+ op = func(i *encInstr, state *EncState, p unsafe.Pointer) {
+ EncodeUint(state, uint64(i.field - state.fieldnum));
+ state.err = engine.encodeStruct(state.w, uintptr(p));
+ state.fieldnum = i.field;
+ };
+ }
}
if op == nil {
panicln("encode can't handle type", typ.String());
@@ -327,33 +376,6 @@
return engine
}
-func (engine *encEngine) encode(w io.Writer, v reflect.Value) os.Error {
- sv, ok := v.(reflect.StructValue);
- if !ok {
- panicln("encoder can't handle non-struct values yet");
- }
- state := new(EncState);
- state.w = w;
- state.base = uintptr(sv.Addr());
- state.fieldnum = -1;
- for i := 0; i < len(engine.instr); i++ {
- instr := &engine.instr[i];
- p := unsafe.Pointer(state.base+instr.offset);
- if instr.indir > 0 {
- if p = encIndirect(p, instr.indir); p == nil {
- state.fieldnum = i;
- continue
- }
- }
- instr.op(instr, state, p);
- if state.err != nil {
- break
- }
- state.fieldnum = i;
- }
- return state.err
-}
-
func Encode(w io.Writer, e interface{}) os.Error {
// Dereference down to the underlying object.
rt := reflect.Typeof(e);
@@ -366,8 +388,11 @@
rt = pt.Sub();
v = reflect.Indirect(v);
}
+ if v.Kind() != reflect.StructKind {
+ return os.ErrorString("decode can't handle " + v.Type().String())
+ }
typeLock.Lock();
engine := getEncEngine(rt);
typeLock.Unlock();
- return engine.encode(w, v);
+ return engine.encodeStruct(w, uintptr(v.(reflect.StructValue).Addr()));
}
