mirror of
https://github.com/golang/go.git
synced 2025-12-08 06:10:04 +00:00
- clean up code creating keys for type maps
- derive int, uint, float, uintptr decoders based on their size - add overflow checks in decode R=rsc DELTA=407 (281 added, 44 deleted, 82 changed) OCL=32286 CL=32290
This commit is contained in:
Rob Pike
parent
08b5b4843b
commit
483e4fc409
5 changed files with 362 additions and 125 deletions
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@ -29,6 +29,10 @@ type decodeState struct {
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fieldnum int; // the last field number read.
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}
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func overflow(name string) os.ErrorString {
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return os.ErrorString(`value for "` + name + `" out of range`);
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}
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// decodeUintReader reads an encoded unsigned integer from an io.Reader.
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// Used only by the Decoder to read the message length.
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func decodeUintReader(r io.Reader, oneByte []byte) (x uint64, err os.Error) {
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@ -50,6 +54,7 @@ func decodeUintReader(r io.Reader, oneByte []byte) (x uint64, err os.Error) {
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// decodeUint reads an encoded unsigned integer from state.r.
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// Sets state.err. If state.err is already non-nil, it does nothing.
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// Does not check for overflow.
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func decodeUint(state *decodeState) (x uint64) {
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if state.err != nil {
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return
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@ -71,6 +76,7 @@ func decodeUint(state *decodeState) (x uint64) {
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// decodeInt reads an encoded signed integer from state.r.
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// Sets state.err. If state.err is already non-nil, it does nothing.
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// Does not check for overflow.
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func decodeInt(state *decodeState) int64 {
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x := decodeUint(state);
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if state.err != nil {
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@ -91,6 +97,7 @@ type decInstr struct {
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field int; // field number of the wire type
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indir int; // how many pointer indirections to reach the value in the struct
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offset uintptr; // offset in the structure of the field to encode
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ovfl os.ErrorString; // error message for overflow/underflow (for arrays, of the elements)
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}
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// Since the encoder writes no zeros, if we arrive at a decoder we have
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@ -126,26 +133,6 @@ func decBool(i *decInstr, state *decodeState, p unsafe.Pointer) {
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*(*bool)(p) = decodeInt(state) != 0;
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}
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func decInt(i *decInstr, state *decodeState, p unsafe.Pointer) {
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if i.indir > 0 {
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if *(*unsafe.Pointer)(p) == nil {
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*(*unsafe.Pointer)(p) = unsafe.Pointer(new(int));
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}
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p = *(*unsafe.Pointer)(p);
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}
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*(*int)(p) = int(decodeInt(state));
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}
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func decUint(i *decInstr, state *decodeState, p unsafe.Pointer) {
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if i.indir > 0 {
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if *(*unsafe.Pointer)(p) == nil {
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*(*unsafe.Pointer)(p) = unsafe.Pointer(new(uint));
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}
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p = *(*unsafe.Pointer)(p);
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}
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*(*uint)(p) = uint(decodeUint(state));
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}
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func decInt8(i *decInstr, state *decodeState, p unsafe.Pointer) {
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if i.indir > 0 {
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if *(*unsafe.Pointer)(p) == nil {
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@ -153,7 +140,12 @@ func decInt8(i *decInstr, state *decodeState, p unsafe.Pointer) {
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}
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p = *(*unsafe.Pointer)(p);
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}
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*(*int8)(p) = int8(decodeInt(state));
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v := decodeInt(state);
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if v < math.MinInt8 || math.MaxInt8 < v {
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state.err = i.ovfl
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} else {
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*(*int8)(p) = int8(v)
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}
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}
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func decUint8(i *decInstr, state *decodeState, p unsafe.Pointer) {
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@ -163,7 +155,12 @@ func decUint8(i *decInstr, state *decodeState, p unsafe.Pointer) {
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}
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p = *(*unsafe.Pointer)(p);
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}
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*(*uint8)(p) = uint8(decodeUint(state));
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v := decodeUint(state);
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if math.MaxUint8 < v {
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state.err = i.ovfl
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} else {
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*(*uint8)(p) = uint8(v)
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}
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}
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func decInt16(i *decInstr, state *decodeState, p unsafe.Pointer) {
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@ -173,7 +170,12 @@ func decInt16(i *decInstr, state *decodeState, p unsafe.Pointer) {
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}
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p = *(*unsafe.Pointer)(p);
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}
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*(*int16)(p) = int16(decodeInt(state));
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v := decodeInt(state);
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if v < math.MinInt16 || math.MaxInt16 < v {
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state.err = i.ovfl
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} else {
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*(*int16)(p) = int16(v)
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}
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}
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func decUint16(i *decInstr, state *decodeState, p unsafe.Pointer) {
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@ -183,7 +185,12 @@ func decUint16(i *decInstr, state *decodeState, p unsafe.Pointer) {
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}
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p = *(*unsafe.Pointer)(p);
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}
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*(*uint16)(p) = uint16(decodeUint(state));
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v := decodeUint(state);
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if math.MaxUint16 < v {
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state.err = i.ovfl
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} else {
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*(*uint16)(p) = uint16(v)
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}
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}
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func decInt32(i *decInstr, state *decodeState, p unsafe.Pointer) {
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@ -193,7 +200,12 @@ func decInt32(i *decInstr, state *decodeState, p unsafe.Pointer) {
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}
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p = *(*unsafe.Pointer)(p);
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}
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*(*int32)(p) = int32(decodeInt(state));
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v := decodeInt(state);
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if v < math.MinInt32 || math.MaxInt32 < v {
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state.err = i.ovfl
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} else {
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*(*int32)(p) = int32(v)
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}
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}
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func decUint32(i *decInstr, state *decodeState, p unsafe.Pointer) {
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@ -203,7 +215,12 @@ func decUint32(i *decInstr, state *decodeState, p unsafe.Pointer) {
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}
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p = *(*unsafe.Pointer)(p);
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}
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*(*uint32)(p) = uint32(decodeUint(state));
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v := decodeUint(state);
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if math.MaxUint32 < v {
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state.err = i.ovfl
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} else {
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*(*uint32)(p) = uint32(v)
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}
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}
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func decInt64(i *decInstr, state *decodeState, p unsafe.Pointer) {
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@ -226,16 +243,6 @@ func decUint64(i *decInstr, state *decodeState, p unsafe.Pointer) {
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*(*uint64)(p) = uint64(decodeUint(state));
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}
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func decUintptr(i *decInstr, state *decodeState, p unsafe.Pointer) {
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if i.indir > 0 {
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if *(*unsafe.Pointer)(p) == nil {
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*(*unsafe.Pointer)(p) = unsafe.Pointer(new(uintptr));
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}
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p = *(*unsafe.Pointer)(p);
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}
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*(*uintptr)(p) = uintptr(decodeUint(state));
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}
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// Floating-point numbers are transmitted as uint64s holding the bits
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// of the underlying representation. They are sent byte-reversed, with
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// the exponent end coming out first, so integer floating point numbers
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@ -251,16 +258,6 @@ func floatFromBits(u uint64) float64 {
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return math.Float64frombits(v);
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}
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func decFloat(i *decInstr, state *decodeState, p unsafe.Pointer) {
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if i.indir > 0 {
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if *(*unsafe.Pointer)(p) == nil {
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*(*unsafe.Pointer)(p) = unsafe.Pointer(new(float));
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}
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p = *(*unsafe.Pointer)(p);
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}
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*(*float)(p) = float(floatFromBits(uint64(decodeUint(state))));
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}
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func decFloat32(i *decInstr, state *decodeState, p unsafe.Pointer) {
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if i.indir > 0 {
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if *(*unsafe.Pointer)(p) == nil {
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@ -268,7 +265,16 @@ func decFloat32(i *decInstr, state *decodeState, p unsafe.Pointer) {
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}
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p = *(*unsafe.Pointer)(p);
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}
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*(*float32)(p) = float32(floatFromBits(uint64(decodeUint(state))));
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v := floatFromBits(decodeUint(state));
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av := v;
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if av < 0 {
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av = -av
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}
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if math.MaxFloat32 < av { // underflow is OK
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state.err = i.ovfl
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} else {
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*(*float32)(p) = float32(v)
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}
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}
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func decFloat64(i *decInstr, state *decodeState, p unsafe.Pointer) {
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@ -386,8 +392,8 @@ func ignoreStruct(engine *decEngine, b *bytes.Buffer) os.Error {
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return state.err
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}
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func decodeArrayHelper(state *decodeState, p uintptr, elemOp decOp, elemWid uintptr, length, elemIndir int) os.Error {
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instr := &decInstr{elemOp, 0, elemIndir, 0};
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func decodeArrayHelper(state *decodeState, p uintptr, elemOp decOp, elemWid uintptr, length, elemIndir int, ovfl os.ErrorString) os.Error {
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instr := &decInstr{elemOp, 0, elemIndir, 0, ovfl};
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for i := 0; i < length && state.err == nil; i++ {
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up := unsafe.Pointer(p);
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if elemIndir > 1 {
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@ -399,7 +405,7 @@ func decodeArrayHelper(state *decodeState, p uintptr, elemOp decOp, elemWid uint
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return state.err
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}
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func decodeArray(atyp *reflect.ArrayType, state *decodeState, p uintptr, elemOp decOp, elemWid uintptr, length, indir, elemIndir int) os.Error {
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func decodeArray(atyp *reflect.ArrayType, state *decodeState, p uintptr, elemOp decOp, elemWid uintptr, length, indir, elemIndir int, ovfl os.ErrorString) os.Error {
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if indir > 0 {
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up := unsafe.Pointer(p);
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if *(*unsafe.Pointer)(up) == nil {
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@ -413,11 +419,11 @@ func decodeArray(atyp *reflect.ArrayType, state *decodeState, p uintptr, elemOp
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if n := decodeUint(state); n != uint64(length) {
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return os.ErrorString("gob: length mismatch in decodeArray");
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}
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return decodeArrayHelper(state, p, elemOp, elemWid, length, elemIndir);
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return decodeArrayHelper(state, p, elemOp, elemWid, length, elemIndir, ovfl);
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}
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func ignoreArrayHelper(state *decodeState, elemOp decOp, length int) os.Error {
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instr := &decInstr{elemOp, 0, 0, 0};
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instr := &decInstr{elemOp, 0, 0, 0, os.ErrorString("no error")};
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for i := 0; i < length && state.err == nil; i++ {
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elemOp(instr, state, nil);
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}
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@ -431,7 +437,7 @@ func ignoreArray(state *decodeState, elemOp decOp, length int) os.Error {
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return ignoreArrayHelper(state, elemOp, length);
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}
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func decodeSlice(atyp *reflect.SliceType, state *decodeState, p uintptr, elemOp decOp, elemWid uintptr, indir, elemIndir int) os.Error {
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func decodeSlice(atyp *reflect.SliceType, state *decodeState, p uintptr, elemOp decOp, elemWid uintptr, indir, elemIndir int, ovfl os.ErrorString) os.Error {
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length := uintptr(decodeUint(state));
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if indir > 0 {
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up := unsafe.Pointer(p);
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@ -448,7 +454,7 @@ func decodeSlice(atyp *reflect.SliceType, state *decodeState, p uintptr, elemOp
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hdrp.Data = uintptr(unsafe.Pointer(&data[0]));
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hdrp.Len = int(length);
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hdrp.Cap = int(length);
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return decodeArrayHelper(state, hdrp.Data, elemOp, elemWid, int(length), elemIndir);
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return decodeArrayHelper(state, hdrp.Data, elemOp, elemWid, int(length), elemIndir, ovfl);
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}
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func ignoreSlice(state *decodeState, elemOp decOp) os.Error {
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@ -456,22 +462,18 @@ func ignoreSlice(state *decodeState, elemOp decOp) os.Error {
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}
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var decOpMap = map[reflect.Type] decOp {
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reflect.Typeof((*reflect.BoolType)(nil)): decBool,
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reflect.Typeof((*reflect.IntType)(nil)): decInt,
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reflect.Typeof((*reflect.Int8Type)(nil)): decInt8,
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reflect.Typeof((*reflect.Int16Type)(nil)): decInt16,
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reflect.Typeof((*reflect.Int32Type)(nil)): decInt32,
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reflect.Typeof((*reflect.Int64Type)(nil)): decInt64,
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reflect.Typeof((*reflect.UintType)(nil)): decUint,
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reflect.Typeof((*reflect.Uint8Type)(nil)): decUint8,
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reflect.Typeof((*reflect.Uint16Type)(nil)): decUint16,
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reflect.Typeof((*reflect.Uint32Type)(nil)): decUint32,
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reflect.Typeof((*reflect.Uint64Type)(nil)): decUint64,
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reflect.Typeof((*reflect.UintptrType)(nil)): decUintptr,
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reflect.Typeof((*reflect.FloatType)(nil)): decFloat,
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reflect.Typeof((*reflect.Float32Type)(nil)): decFloat32,
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reflect.Typeof((*reflect.Float64Type)(nil)): decFloat64,
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reflect.Typeof((*reflect.StringType)(nil)): decString,
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valueKind(false): decBool,
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valueKind(int8(0)): decInt8,
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valueKind(int16(0)): decInt16,
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valueKind(int32(0)): decInt32,
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valueKind(int64(0)): decInt64,
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valueKind(uint8(0)): decUint8,
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valueKind(uint16(0)): decUint16,
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valueKind(uint32(0)): decUint32,
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valueKind(uint64(0)): decUint64,
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valueKind(float32(0)): decFloat32,
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valueKind(float64(0)): decFloat64,
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valueKind("x"): decString,
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}
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var decIgnoreOpMap = map[typeId] decOp {
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@ -488,34 +490,38 @@ func getIgnoreEnginePtr(wireId typeId) (enginePtr **decEngine, err os.Error)
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// Return the decoding op for the base type under rt and
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// the indirection count to reach it.
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func decOpFor(wireId typeId, rt reflect.Type) (decOp, int, os.Error) {
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func decOpFor(wireId typeId, rt reflect.Type, name string) (decOp, int, os.Error) {
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typ, indir := indirect(rt);
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op, ok := decOpMap[reflect.Typeof(typ)];
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if !ok {
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// Special cases
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switch t := typ.(type) {
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case *reflect.SliceType:
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name = "element of " + name;
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if _, ok := t.Elem().(*reflect.Uint8Type); ok {
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op = decUint8Array;
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break;
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}
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elemId := wireId.gobType().(*sliceType).Elem;
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elemOp, elemIndir, err := decOpFor(elemId, t.Elem());
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elemOp, elemIndir, err := decOpFor(elemId, t.Elem(), name);
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if err != nil {
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return nil, 0, err
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}
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ovfl := overflow(name);
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op = func(i *decInstr, state *decodeState, p unsafe.Pointer) {
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state.err = decodeSlice(t, state, uintptr(p), elemOp, t.Elem().Size(), i.indir, elemIndir);
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state.err = decodeSlice(t, state, uintptr(p), elemOp, t.Elem().Size(), i.indir, elemIndir, ovfl);
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};
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case *reflect.ArrayType:
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name = "element of " + name;
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elemId := wireId.gobType().(*arrayType).Elem;
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elemOp, elemIndir, err := decOpFor(elemId, t.Elem());
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elemOp, elemIndir, err := decOpFor(elemId, t.Elem(), name);
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if err != nil {
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return nil, 0, err
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}
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ovfl := overflow(name);
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op = func(i *decInstr, state *decodeState, p unsafe.Pointer) {
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state.err = decodeArray(t, state, uintptr(p), elemOp, t.Elem().Size(), t.Len(), i.indir, elemIndir);
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state.err = decodeArray(t, state, uintptr(p), elemOp, t.Elem().Size(), t.Len(), i.indir, elemIndir, ovfl);
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};
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case *reflect.StructType:
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@ -658,23 +664,25 @@ func compileDec(wireId typeId, rt reflect.Type) (engine *decEngine, err os.Error
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wireField := wireStruct.field[fieldnum];
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// Find the field of the local type with the same name.
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localField, present := srt.FieldByName(wireField.name);
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ovfl := overflow(wireField.name);
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// TODO(r): anonymous names
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if !present || localField.Anonymous {
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op, err := decIgnoreOpFor(wireField.id);
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if err != nil {
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return nil, err
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}
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engine.instr[fieldnum] = decInstr{op, fieldnum, 0, 0};
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engine.instr[fieldnum] = decInstr{op, fieldnum, 0, 0, ovfl};
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continue;
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}
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if !compatibleType(localField.Type, wireField.id) {
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return nil, os.ErrorString("gob: wrong type for field " + wireField.name + " in type " + wireId.Name());
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details := " (" + wireField.id.String() + " incompatible with " + localField.Type.String() + ") in type " + wireId.Name();
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return nil, os.ErrorString("gob: wrong type for field " + wireField.name + details);
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}
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op, indir, err := decOpFor(wireField.id, localField.Type);
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op, indir, err := decOpFor(wireField.id, localField.Type, localField.Name);
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if err != nil {
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return nil, err
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}
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engine.instr[fieldnum] = decInstr{op, fieldnum, indir, uintptr(localField.Offset)};
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engine.instr[fieldnum] = decInstr{op, fieldnum, indir, uintptr(localField.Offset), ovfl};
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engine.numInstr++;
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}
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return;
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@ -746,3 +754,44 @@ func decode(b *bytes.Buffer, wireId typeId, e interface{}) os.Error {
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}
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return decodeStruct(engine, rt.(*reflect.StructType), b, uintptr(v.Addr()), 0);
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}
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func init() {
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// We assume that the size of float is sufficient to tell us whether it is
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// equivalent to float32 or to float64. This is very unlikely to be wrong.
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var op decOp;
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switch unsafe.Sizeof(float(0)) {
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case unsafe.Sizeof(float32(0)):
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op = decFloat32;
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case unsafe.Sizeof(float64(0)):
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op = decFloat64;
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default:
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panic("gob: unknown size of float", unsafe.Sizeof(float(0)));
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}
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decOpMap[valueKind(float(0))] = op;
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// A similar assumption about int and uint. Also assume int and uint have the same size.
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var uop decOp;
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switch unsafe.Sizeof(int(0)) {
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case unsafe.Sizeof(int32(0)):
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op = decInt32;
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uop = decUint32;
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case unsafe.Sizeof(int64(0)):
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op = decInt64;
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uop = decUint64;
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default:
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panic("gob: unknown size of int/uint", unsafe.Sizeof(int(0)));
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}
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||||
decOpMap[valueKind(int(0))] = op;
|
||||
decOpMap[valueKind(uint(0))] = uop;
|
||||
|
||||
// Finally uintptr
|
||||
switch unsafe.Sizeof(uintptr(0)) {
|
||||
case unsafe.Sizeof(uint32(0)):
|
||||
uop = decUint32;
|
||||
case unsafe.Sizeof(uint64(0)):
|
||||
uop = decUint64;
|
||||
default:
|
||||
panic("gob: unknown size of uintptr", unsafe.Sizeof(uintptr(0)));
|
||||
}
|
||||
decOpMap[valueKind(uintptr(0))] = uop;
|
||||
}
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue