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path: root/src/pkg/encoding/gob/decode.go
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Diffstat (limited to 'src/pkg/encoding/gob/decode.go')
-rw-r--r--src/pkg/encoding/gob/decode.go1317
1 files changed, 0 insertions, 1317 deletions
diff --git a/src/pkg/encoding/gob/decode.go b/src/pkg/encoding/gob/decode.go
deleted file mode 100644
index d8513148e..000000000
--- a/src/pkg/encoding/gob/decode.go
+++ /dev/null
@@ -1,1317 +0,0 @@
-// Copyright 2009 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package gob
-
-// TODO(rsc): When garbage collector changes, revisit
-// the allocations in this file that use unsafe.Pointer.
-
-import (
- "bytes"
- "encoding"
- "errors"
- "io"
- "math"
- "reflect"
- "unsafe"
-)
-
-var (
- errBadUint = errors.New("gob: encoded unsigned integer out of range")
- errBadType = errors.New("gob: unknown type id or corrupted data")
- errRange = errors.New("gob: bad data: field numbers out of bounds")
-)
-
-// decoderState is the execution state of an instance of the decoder. A new state
-// is created for nested objects.
-type decoderState struct {
- dec *Decoder
- // The buffer is stored with an extra indirection because it may be replaced
- // if we load a type during decode (when reading an interface value).
- b *bytes.Buffer
- fieldnum int // the last field number read.
- buf []byte
- next *decoderState // for free list
-}
-
-// We pass the bytes.Buffer separately for easier testing of the infrastructure
-// without requiring a full Decoder.
-func (dec *Decoder) newDecoderState(buf *bytes.Buffer) *decoderState {
- d := dec.freeList
- if d == nil {
- d = new(decoderState)
- d.dec = dec
- d.buf = make([]byte, uint64Size)
- } else {
- dec.freeList = d.next
- }
- d.b = buf
- return d
-}
-
-func (dec *Decoder) freeDecoderState(d *decoderState) {
- d.next = dec.freeList
- dec.freeList = d
-}
-
-func overflow(name string) error {
- return errors.New(`value for "` + name + `" out of range`)
-}
-
-// decodeUintReader reads an encoded unsigned integer from an io.Reader.
-// Used only by the Decoder to read the message length.
-func decodeUintReader(r io.Reader, buf []byte) (x uint64, width int, err error) {
- width = 1
- n, err := io.ReadFull(r, buf[0:width])
- if n == 0 {
- return
- }
- b := buf[0]
- if b <= 0x7f {
- return uint64(b), width, nil
- }
- n = -int(int8(b))
- if n > uint64Size {
- err = errBadUint
- return
- }
- width, err = io.ReadFull(r, buf[0:n])
- if err != nil {
- if err == io.EOF {
- err = io.ErrUnexpectedEOF
- }
- return
- }
- // Could check that the high byte is zero but it's not worth it.
- for _, b := range buf[0:width] {
- x = x<<8 | uint64(b)
- }
- width++ // +1 for length byte
- return
-}
-
-// decodeUint reads an encoded unsigned integer from state.r.
-// Does not check for overflow.
-func (state *decoderState) decodeUint() (x uint64) {
- b, err := state.b.ReadByte()
- if err != nil {
- error_(err)
- }
- if b <= 0x7f {
- return uint64(b)
- }
- n := -int(int8(b))
- if n > uint64Size {
- error_(errBadUint)
- }
- width, err := state.b.Read(state.buf[0:n])
- if err != nil {
- error_(err)
- }
- // Don't need to check error; it's safe to loop regardless.
- // Could check that the high byte is zero but it's not worth it.
- for _, b := range state.buf[0:width] {
- x = x<<8 | uint64(b)
- }
- return x
-}
-
-// decodeInt reads an encoded signed integer from state.r.
-// Does not check for overflow.
-func (state *decoderState) decodeInt() int64 {
- x := state.decodeUint()
- if x&1 != 0 {
- return ^int64(x >> 1)
- }
- return int64(x >> 1)
-}
-
-// decOp is the signature of a decoding operator for a given type.
-type decOp func(i *decInstr, state *decoderState, p unsafe.Pointer)
-
-// The 'instructions' of the decoding machine
-type decInstr struct {
- op decOp
- field int // field number of the wire type
- indir int // how many pointer indirections to reach the value in the struct
- offset uintptr // offset in the structure of the field to encode
- ovfl error // error message for overflow/underflow (for arrays, of the elements)
-}
-
-// Since the encoder writes no zeros, if we arrive at a decoder we have
-// a value to extract and store. The field number has already been read
-// (it's how we knew to call this decoder).
-// Each decoder is responsible for handling any indirections associated
-// with the data structure. If any pointer so reached is nil, allocation must
-// be done.
-
-// Walk the pointer hierarchy, allocating if we find a nil. Stop one before the end.
-func decIndirect(p unsafe.Pointer, indir int) unsafe.Pointer {
- for ; indir > 1; indir-- {
- if *(*unsafe.Pointer)(p) == nil {
- // Allocation required
- *(*unsafe.Pointer)(p) = unsafe.Pointer(new(unsafe.Pointer))
- }
- p = *(*unsafe.Pointer)(p)
- }
- return p
-}
-
-// ignoreUint discards a uint value with no destination.
-func ignoreUint(i *decInstr, state *decoderState, p unsafe.Pointer) {
- state.decodeUint()
-}
-
-// ignoreTwoUints discards a uint value with no destination. It's used to skip
-// complex values.
-func ignoreTwoUints(i *decInstr, state *decoderState, p unsafe.Pointer) {
- state.decodeUint()
- state.decodeUint()
-}
-
-// decBool decodes a uint and stores it as a boolean through p.
-func decBool(i *decInstr, state *decoderState, p unsafe.Pointer) {
- if i.indir > 0 {
- if *(*unsafe.Pointer)(p) == nil {
- *(*unsafe.Pointer)(p) = unsafe.Pointer(new(bool))
- }
- p = *(*unsafe.Pointer)(p)
- }
- *(*bool)(p) = state.decodeUint() != 0
-}
-
-// decInt8 decodes an integer and stores it as an int8 through p.
-func decInt8(i *decInstr, state *decoderState, p unsafe.Pointer) {
- if i.indir > 0 {
- if *(*unsafe.Pointer)(p) == nil {
- *(*unsafe.Pointer)(p) = unsafe.Pointer(new(int8))
- }
- p = *(*unsafe.Pointer)(p)
- }
- v := state.decodeInt()
- if v < math.MinInt8 || math.MaxInt8 < v {
- error_(i.ovfl)
- } else {
- *(*int8)(p) = int8(v)
- }
-}
-
-// decUint8 decodes an unsigned integer and stores it as a uint8 through p.
-func decUint8(i *decInstr, state *decoderState, p unsafe.Pointer) {
- if i.indir > 0 {
- if *(*unsafe.Pointer)(p) == nil {
- *(*unsafe.Pointer)(p) = unsafe.Pointer(new(uint8))
- }
- p = *(*unsafe.Pointer)(p)
- }
- v := state.decodeUint()
- if math.MaxUint8 < v {
- error_(i.ovfl)
- } else {
- *(*uint8)(p) = uint8(v)
- }
-}
-
-// decInt16 decodes an integer and stores it as an int16 through p.
-func decInt16(i *decInstr, state *decoderState, p unsafe.Pointer) {
- if i.indir > 0 {
- if *(*unsafe.Pointer)(p) == nil {
- *(*unsafe.Pointer)(p) = unsafe.Pointer(new(int16))
- }
- p = *(*unsafe.Pointer)(p)
- }
- v := state.decodeInt()
- if v < math.MinInt16 || math.MaxInt16 < v {
- error_(i.ovfl)
- } else {
- *(*int16)(p) = int16(v)
- }
-}
-
-// decUint16 decodes an unsigned integer and stores it as a uint16 through p.
-func decUint16(i *decInstr, state *decoderState, p unsafe.Pointer) {
- if i.indir > 0 {
- if *(*unsafe.Pointer)(p) == nil {
- *(*unsafe.Pointer)(p) = unsafe.Pointer(new(uint16))
- }
- p = *(*unsafe.Pointer)(p)
- }
- v := state.decodeUint()
- if math.MaxUint16 < v {
- error_(i.ovfl)
- } else {
- *(*uint16)(p) = uint16(v)
- }
-}
-
-// decInt32 decodes an integer and stores it as an int32 through p.
-func decInt32(i *decInstr, state *decoderState, p unsafe.Pointer) {
- if i.indir > 0 {
- if *(*unsafe.Pointer)(p) == nil {
- *(*unsafe.Pointer)(p) = unsafe.Pointer(new(int32))
- }
- p = *(*unsafe.Pointer)(p)
- }
- v := state.decodeInt()
- if v < math.MinInt32 || math.MaxInt32 < v {
- error_(i.ovfl)
- } else {
- *(*int32)(p) = int32(v)
- }
-}
-
-// decUint32 decodes an unsigned integer and stores it as a uint32 through p.
-func decUint32(i *decInstr, state *decoderState, p unsafe.Pointer) {
- if i.indir > 0 {
- if *(*unsafe.Pointer)(p) == nil {
- *(*unsafe.Pointer)(p) = unsafe.Pointer(new(uint32))
- }
- p = *(*unsafe.Pointer)(p)
- }
- v := state.decodeUint()
- if math.MaxUint32 < v {
- error_(i.ovfl)
- } else {
- *(*uint32)(p) = uint32(v)
- }
-}
-
-// decInt64 decodes an integer and stores it as an int64 through p.
-func decInt64(i *decInstr, state *decoderState, p unsafe.Pointer) {
- if i.indir > 0 {
- if *(*unsafe.Pointer)(p) == nil {
- *(*unsafe.Pointer)(p) = unsafe.Pointer(new(int64))
- }
- p = *(*unsafe.Pointer)(p)
- }
- *(*int64)(p) = int64(state.decodeInt())
-}
-
-// decUint64 decodes an unsigned integer and stores it as a uint64 through p.
-func decUint64(i *decInstr, state *decoderState, p unsafe.Pointer) {
- if i.indir > 0 {
- if *(*unsafe.Pointer)(p) == nil {
- *(*unsafe.Pointer)(p) = unsafe.Pointer(new(uint64))
- }
- p = *(*unsafe.Pointer)(p)
- }
- *(*uint64)(p) = uint64(state.decodeUint())
-}
-
-// 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
-// unswizzling.
-func floatFromBits(u uint64) float64 {
- var v uint64
- for i := 0; i < 8; i++ {
- v <<= 8
- v |= u & 0xFF
- u >>= 8
- }
- return math.Float64frombits(v)
-}
-
-// storeFloat32 decodes an unsigned integer, treats it as a 32-bit floating-point
-// number, and stores it through p. It's a helper function for float32 and complex64.
-func storeFloat32(i *decInstr, state *decoderState, p unsafe.Pointer) {
- v := floatFromBits(state.decodeUint())
- av := v
- if av < 0 {
- av = -av
- }
- // +Inf is OK in both 32- and 64-bit floats. Underflow is always OK.
- if math.MaxFloat32 < av && av <= math.MaxFloat64 {
- error_(i.ovfl)
- } else {
- *(*float32)(p) = float32(v)
- }
-}
-
-// decFloat32 decodes an unsigned integer, treats it as a 32-bit floating-point
-// number, and stores it through p.
-func decFloat32(i *decInstr, state *decoderState, p unsafe.Pointer) {
- if i.indir > 0 {
- if *(*unsafe.Pointer)(p) == nil {
- *(*unsafe.Pointer)(p) = unsafe.Pointer(new(float32))
- }
- p = *(*unsafe.Pointer)(p)
- }
- storeFloat32(i, state, p)
-}
-
-// decFloat64 decodes an unsigned integer, treats it as a 64-bit floating-point
-// number, and stores it through p.
-func decFloat64(i *decInstr, state *decoderState, p unsafe.Pointer) {
- if i.indir > 0 {
- if *(*unsafe.Pointer)(p) == nil {
- *(*unsafe.Pointer)(p) = unsafe.Pointer(new(float64))
- }
- p = *(*unsafe.Pointer)(p)
- }
- *(*float64)(p) = floatFromBits(uint64(state.decodeUint()))
-}
-
-// decComplex64 decodes a pair of unsigned integers, treats them as a
-// pair of floating point numbers, and stores them as a complex64 through p.
-// The real part comes first.
-func decComplex64(i *decInstr, state *decoderState, p unsafe.Pointer) {
- if i.indir > 0 {
- if *(*unsafe.Pointer)(p) == nil {
- *(*unsafe.Pointer)(p) = unsafe.Pointer(new(complex64))
- }
- p = *(*unsafe.Pointer)(p)
- }
- storeFloat32(i, state, p)
- storeFloat32(i, state, unsafe.Pointer(uintptr(p)+unsafe.Sizeof(float32(0))))
-}
-
-// decComplex128 decodes a pair of unsigned integers, treats them as a
-// pair of floating point numbers, and stores them as a complex128 through p.
-// The real part comes first.
-func decComplex128(i *decInstr, state *decoderState, p unsafe.Pointer) {
- if i.indir > 0 {
- if *(*unsafe.Pointer)(p) == nil {
- *(*unsafe.Pointer)(p) = unsafe.Pointer(new(complex128))
- }
- p = *(*unsafe.Pointer)(p)
- }
- real := floatFromBits(uint64(state.decodeUint()))
- imag := floatFromBits(uint64(state.decodeUint()))
- *(*complex128)(p) = complex(real, imag)
-}
-
-// decUint8Slice decodes a byte slice and stores through p a slice header
-// describing the data.
-// uint8 slices are encoded as an unsigned count followed by the raw bytes.
-func decUint8Slice(i *decInstr, state *decoderState, p unsafe.Pointer) {
- if i.indir > 0 {
- if *(*unsafe.Pointer)(p) == nil {
- *(*unsafe.Pointer)(p) = unsafe.Pointer(new([]uint8))
- }
- p = *(*unsafe.Pointer)(p)
- }
- n := state.decodeUint()
- if n > uint64(state.b.Len()) {
- errorf("length of []byte exceeds input size (%d bytes)", n)
- }
- slice := (*[]uint8)(p)
- if uint64(cap(*slice)) < n {
- *slice = make([]uint8, n)
- } else {
- *slice = (*slice)[0:n]
- }
- if _, err := state.b.Read(*slice); err != nil {
- errorf("error decoding []byte: %s", err)
- }
-}
-
-// decString decodes byte array and stores through p a string header
-// describing the data.
-// Strings are encoded as an unsigned count followed by the raw bytes.
-func decString(i *decInstr, state *decoderState, p unsafe.Pointer) {
- if i.indir > 0 {
- if *(*unsafe.Pointer)(p) == nil {
- *(*unsafe.Pointer)(p) = unsafe.Pointer(new(string))
- }
- p = *(*unsafe.Pointer)(p)
- }
- n := state.decodeUint()
- if n > uint64(state.b.Len()) {
- errorf("string length exceeds input size (%d bytes)", n)
- }
- b := make([]byte, n)
- state.b.Read(b)
- // It would be a shame to do the obvious thing here,
- // *(*string)(p) = string(b)
- // because we've already allocated the storage and this would
- // allocate again and copy. So we do this ugly hack, which is even
- // even more unsafe than it looks as it depends the memory
- // representation of a string matching the beginning of the memory
- // representation of a byte slice (a byte slice is longer).
- *(*string)(p) = *(*string)(unsafe.Pointer(&b))
-}
-
-// ignoreUint8Array skips over the data for a byte slice value with no destination.
-func ignoreUint8Array(i *decInstr, state *decoderState, p unsafe.Pointer) {
- b := make([]byte, state.decodeUint())
- state.b.Read(b)
-}
-
-// Execution engine
-
-// The encoder engine is an array of instructions indexed by field number of the incoming
-// decoder. It is executed with random access according to field number.
-type decEngine struct {
- instr []decInstr
- numInstr int // the number of active instructions
-}
-
-// allocate makes sure storage is available for an object of underlying type rtyp
-// that is indir levels of indirection through p.
-func allocate(rtyp reflect.Type, p unsafe.Pointer, indir int) unsafe.Pointer {
- if indir == 0 {
- return p
- }
- up := p
- if indir > 1 {
- up = decIndirect(up, indir)
- }
- if *(*unsafe.Pointer)(up) == nil {
- // Allocate object.
- *(*unsafe.Pointer)(up) = unsafe.Pointer(reflect.New(rtyp).Pointer())
- }
- return *(*unsafe.Pointer)(up)
-}
-
-// decodeSingle decodes a top-level value that is not a struct and stores it through p.
-// Such values are preceded by a zero, making them have the memory layout of a
-// struct field (although with an illegal field number).
-func (dec *Decoder) decodeSingle(engine *decEngine, ut *userTypeInfo, basep unsafe.Pointer) {
- state := dec.newDecoderState(&dec.buf)
- state.fieldnum = singletonField
- delta := int(state.decodeUint())
- if delta != 0 {
- errorf("decode: corrupted data: non-zero delta for singleton")
- }
- instr := &engine.instr[singletonField]
- if instr.indir != ut.indir {
- errorf("internal error: inconsistent indirection instr %d ut %d", instr.indir, ut.indir)
- }
- ptr := basep // offset will be zero
- if instr.indir > 1 {
- ptr = decIndirect(ptr, instr.indir)
- }
- instr.op(instr, state, ptr)
- dec.freeDecoderState(state)
-}
-
-// decodeStruct decodes a top-level struct and stores it through p.
-// Indir is for the value, not the type. At the time of the call it may
-// differ from ut.indir, which was computed when the engine was built.
-// This state cannot arise for decodeSingle, which is called directly
-// from the user's value, not from the innards of an engine.
-func (dec *Decoder) decodeStruct(engine *decEngine, ut *userTypeInfo, p unsafe.Pointer, indir int) {
- p = allocate(ut.base, p, indir)
- state := dec.newDecoderState(&dec.buf)
- state.fieldnum = -1
- basep := p
- for state.b.Len() > 0 {
- delta := int(state.decodeUint())
- if delta < 0 {
- errorf("decode: corrupted data: negative delta")
- }
- if delta == 0 { // struct terminator is zero delta fieldnum
- break
- }
- fieldnum := state.fieldnum + delta
- if fieldnum >= len(engine.instr) {
- error_(errRange)
- break
- }
- instr := &engine.instr[fieldnum]
- p := unsafe.Pointer(uintptr(basep) + instr.offset)
- if instr.indir > 1 {
- p = decIndirect(p, instr.indir)
- }
- instr.op(instr, state, p)
- state.fieldnum = fieldnum
- }
- dec.freeDecoderState(state)
-}
-
-// ignoreStruct discards the data for a struct with no destination.
-func (dec *Decoder) ignoreStruct(engine *decEngine) {
- state := dec.newDecoderState(&dec.buf)
- state.fieldnum = -1
- for state.b.Len() > 0 {
- delta := int(state.decodeUint())
- if delta < 0 {
- errorf("ignore decode: corrupted data: negative delta")
- }
- if delta == 0 { // struct terminator is zero delta fieldnum
- break
- }
- fieldnum := state.fieldnum + delta
- if fieldnum >= len(engine.instr) {
- error_(errRange)
- }
- instr := &engine.instr[fieldnum]
- instr.op(instr, state, unsafe.Pointer(nil))
- state.fieldnum = fieldnum
- }
- dec.freeDecoderState(state)
-}
-
-// ignoreSingle discards the data for a top-level non-struct value with no
-// destination. It's used when calling Decode with a nil value.
-func (dec *Decoder) ignoreSingle(engine *decEngine) {
- state := dec.newDecoderState(&dec.buf)
- state.fieldnum = singletonField
- delta := int(state.decodeUint())
- if delta != 0 {
- errorf("decode: corrupted data: non-zero delta for singleton")
- }
- instr := &engine.instr[singletonField]
- instr.op(instr, state, unsafe.Pointer(nil))
- dec.freeDecoderState(state)
-}
-
-// decodeArrayHelper does the work for decoding arrays and slices.
-func (dec *Decoder) decodeArrayHelper(state *decoderState, p unsafe.Pointer, elemOp decOp, elemWid uintptr, length, elemIndir int, ovfl error) {
- instr := &decInstr{elemOp, 0, elemIndir, 0, ovfl}
- for i := 0; i < length; i++ {
- if state.b.Len() == 0 {
- errorf("decoding array or slice: length exceeds input size (%d elements)", length)
- }
- up := p
- if elemIndir > 1 {
- up = decIndirect(up, elemIndir)
- }
- elemOp(instr, state, up)
- p = unsafe.Pointer(uintptr(p) + elemWid)
- }
-}
-
-// decodeArray decodes an array and stores it through p, that is, p points to the zeroth element.
-// The length is an unsigned integer preceding the elements. Even though the length is redundant
-// (it's part of the type), it's a useful check and is included in the encoding.
-func (dec *Decoder) decodeArray(atyp reflect.Type, state *decoderState, p unsafe.Pointer, elemOp decOp, elemWid uintptr, length, indir, elemIndir int, ovfl error) {
- if indir > 0 {
- p = allocate(atyp, p, 1) // All but the last level has been allocated by dec.Indirect
- }
- if n := state.decodeUint(); n != uint64(length) {
- errorf("length mismatch in decodeArray")
- }
- dec.decodeArrayHelper(state, p, elemOp, elemWid, length, elemIndir, ovfl)
-}
-
-// decodeIntoValue is a helper for map decoding. Since maps are decoded using reflection,
-// unlike the other items we can't use a pointer directly.
-func decodeIntoValue(state *decoderState, op decOp, indir int, v reflect.Value, ovfl error) reflect.Value {
- instr := &decInstr{op, 0, indir, 0, ovfl}
- up := unsafeAddr(v)
- if indir > 1 {
- up = decIndirect(up, indir)
- }
- op(instr, state, up)
- return v
-}
-
-// decodeMap decodes a map and stores its header through p.
-// Maps are encoded as a length followed by key:value pairs.
-// Because the internals of maps are not visible to us, we must
-// use reflection rather than pointer magic.
-func (dec *Decoder) decodeMap(mtyp reflect.Type, state *decoderState, p unsafe.Pointer, keyOp, elemOp decOp, indir, keyIndir, elemIndir int, ovfl error) {
- if indir > 0 {
- p = allocate(mtyp, p, 1) // All but the last level has been allocated by dec.Indirect
- }
- up := unsafe.Pointer(p)
- if *(*unsafe.Pointer)(up) == nil { // maps are represented as a pointer in the runtime
- // Allocate map.
- *(*unsafe.Pointer)(up) = unsafe.Pointer(reflect.MakeMap(mtyp).Pointer())
- }
- // Maps cannot be accessed by moving addresses around the way
- // that slices etc. can. We must recover a full reflection value for
- // the iteration.
- v := reflect.NewAt(mtyp, unsafe.Pointer(p)).Elem()
- n := int(state.decodeUint())
- for i := 0; i < n; i++ {
- key := decodeIntoValue(state, keyOp, keyIndir, allocValue(mtyp.Key()), ovfl)
- elem := decodeIntoValue(state, elemOp, elemIndir, allocValue(mtyp.Elem()), ovfl)
- v.SetMapIndex(key, elem)
- }
-}
-
-// ignoreArrayHelper does the work for discarding arrays and slices.
-func (dec *Decoder) ignoreArrayHelper(state *decoderState, elemOp decOp, length int) {
- instr := &decInstr{elemOp, 0, 0, 0, errors.New("no error")}
- for i := 0; i < length; i++ {
- elemOp(instr, state, nil)
- }
-}
-
-// ignoreArray discards the data for an array value with no destination.
-func (dec *Decoder) ignoreArray(state *decoderState, elemOp decOp, length int) {
- if n := state.decodeUint(); n != uint64(length) {
- errorf("length mismatch in ignoreArray")
- }
- dec.ignoreArrayHelper(state, elemOp, length)
-}
-
-// ignoreMap discards the data for a map value with no destination.
-func (dec *Decoder) ignoreMap(state *decoderState, keyOp, elemOp decOp) {
- n := int(state.decodeUint())
- keyInstr := &decInstr{keyOp, 0, 0, 0, errors.New("no error")}
- elemInstr := &decInstr{elemOp, 0, 0, 0, errors.New("no error")}
- for i := 0; i < n; i++ {
- keyOp(keyInstr, state, nil)
- elemOp(elemInstr, state, nil)
- }
-}
-
-// decodeSlice decodes a slice and stores the slice header through p.
-// Slices are encoded as an unsigned length followed by the elements.
-func (dec *Decoder) decodeSlice(atyp reflect.Type, state *decoderState, p unsafe.Pointer, elemOp decOp, elemWid uintptr, indir, elemIndir int, ovfl error) {
- nr := state.decodeUint()
- n := int(nr)
- if indir > 0 {
- if *(*unsafe.Pointer)(p) == nil {
- // Allocate the slice header.
- *(*unsafe.Pointer)(p) = unsafe.Pointer(new([]unsafe.Pointer))
- }
- p = *(*unsafe.Pointer)(p)
- }
- // Allocate storage for the slice elements, that is, the underlying array,
- // if the existing slice does not have the capacity.
- // Always write a header at p.
- hdrp := (*reflect.SliceHeader)(p)
- if hdrp.Cap < n {
- hdrp.Data = reflect.MakeSlice(atyp, n, n).Pointer()
- hdrp.Cap = n
- }
- hdrp.Len = n
- dec.decodeArrayHelper(state, unsafe.Pointer(hdrp.Data), elemOp, elemWid, n, elemIndir, ovfl)
-}
-
-// ignoreSlice skips over the data for a slice value with no destination.
-func (dec *Decoder) ignoreSlice(state *decoderState, elemOp decOp) {
- dec.ignoreArrayHelper(state, elemOp, int(state.decodeUint()))
-}
-
-// setInterfaceValue sets an interface value to a concrete value,
-// but first it checks that the assignment will succeed.
-func setInterfaceValue(ivalue reflect.Value, value reflect.Value) {
- if !value.Type().AssignableTo(ivalue.Type()) {
- errorf("%s is not assignable to type %s", value.Type(), ivalue.Type())
- }
- ivalue.Set(value)
-}
-
-// decodeInterface decodes an interface value and stores it through p.
-// Interfaces are encoded as the name of a concrete type followed by a value.
-// If the name is empty, the value is nil and no value is sent.
-func (dec *Decoder) decodeInterface(ityp reflect.Type, state *decoderState, p unsafe.Pointer, indir int) {
- // Create a writable interface reflect.Value. We need one even for the nil case.
- ivalue := allocValue(ityp)
- // Read the name of the concrete type.
- nr := state.decodeUint()
- if nr < 0 || nr > 1<<31 { // zero is permissible for anonymous types
- errorf("invalid type name length %d", nr)
- }
- if nr > uint64(state.b.Len()) {
- errorf("invalid type name length %d: exceeds input size", nr)
- }
- b := make([]byte, nr)
- state.b.Read(b)
- name := string(b)
- if name == "" {
- // Copy the representation of the nil interface value to the target.
- // This is horribly unsafe and special.
- if indir > 0 {
- p = allocate(ityp, p, 1) // All but the last level has been allocated by dec.Indirect
- }
- *(*[2]uintptr)(unsafe.Pointer(p)) = ivalue.InterfaceData()
- return
- }
- if len(name) > 1024 {
- errorf("name too long (%d bytes): %.20q...", len(name), name)
- }
- // The concrete type must be registered.
- registerLock.RLock()
- typ, ok := nameToConcreteType[name]
- registerLock.RUnlock()
- if !ok {
- errorf("name not registered for interface: %q", name)
- }
- // Read the type id of the concrete value.
- concreteId := dec.decodeTypeSequence(true)
- if concreteId < 0 {
- error_(dec.err)
- }
- // Byte count of value is next; we don't care what it is (it's there
- // in case we want to ignore the value by skipping it completely).
- state.decodeUint()
- // Read the concrete value.
- value := allocValue(typ)
- dec.decodeValue(concreteId, value)
- if dec.err != nil {
- error_(dec.err)
- }
- // Allocate the destination interface value.
- if indir > 0 {
- p = allocate(ityp, p, 1) // All but the last level has been allocated by dec.Indirect
- }
- // Assign the concrete value to the interface.
- // Tread carefully; it might not satisfy the interface.
- setInterfaceValue(ivalue, value)
- // Copy the representation of the interface value to the target.
- // This is horribly unsafe and special.
- *(*[2]uintptr)(unsafe.Pointer(p)) = ivalue.InterfaceData()
-}
-
-// ignoreInterface discards the data for an interface value with no destination.
-func (dec *Decoder) ignoreInterface(state *decoderState) {
- // Read the name of the concrete type.
- b := make([]byte, state.decodeUint())
- _, err := state.b.Read(b)
- if err != nil {
- error_(err)
- }
- id := dec.decodeTypeSequence(true)
- if id < 0 {
- error_(dec.err)
- }
- // At this point, the decoder buffer contains a delimited value. Just toss it.
- state.b.Next(int(state.decodeUint()))
-}
-
-// decodeGobDecoder decodes something implementing the GobDecoder interface.
-// The data is encoded as a byte slice.
-func (dec *Decoder) decodeGobDecoder(ut *userTypeInfo, state *decoderState, v reflect.Value) {
- // Read the bytes for the value.
- b := make([]byte, state.decodeUint())
- _, err := state.b.Read(b)
- if err != nil {
- error_(err)
- }
- // We know it's one of these.
- switch ut.externalDec {
- case xGob:
- err = v.Interface().(GobDecoder).GobDecode(b)
- case xBinary:
- err = v.Interface().(encoding.BinaryUnmarshaler).UnmarshalBinary(b)
- case xText:
- err = v.Interface().(encoding.TextUnmarshaler).UnmarshalText(b)
- }
- if err != nil {
- error_(err)
- }
-}
-
-// ignoreGobDecoder discards the data for a GobDecoder value with no destination.
-func (dec *Decoder) ignoreGobDecoder(state *decoderState) {
- // Read the bytes for the value.
- b := make([]byte, state.decodeUint())
- _, err := state.b.Read(b)
- if err != nil {
- error_(err)
- }
-}
-
-// Index by Go types.
-var decOpTable = [...]decOp{
- reflect.Bool: decBool,
- reflect.Int8: decInt8,
- reflect.Int16: decInt16,
- reflect.Int32: decInt32,
- reflect.Int64: decInt64,
- reflect.Uint8: decUint8,
- reflect.Uint16: decUint16,
- reflect.Uint32: decUint32,
- reflect.Uint64: decUint64,
- reflect.Float32: decFloat32,
- reflect.Float64: decFloat64,
- reflect.Complex64: decComplex64,
- reflect.Complex128: decComplex128,
- reflect.String: decString,
-}
-
-// Indexed by gob types. tComplex will be added during type.init().
-var decIgnoreOpMap = map[typeId]decOp{
- tBool: ignoreUint,
- tInt: ignoreUint,
- tUint: ignoreUint,
- tFloat: ignoreUint,
- tBytes: ignoreUint8Array,
- tString: ignoreUint8Array,
- tComplex: ignoreTwoUints,
-}
-
-// decOpFor returns the decoding op for the base type under rt and
-// the indirection count to reach it.
-func (dec *Decoder) decOpFor(wireId typeId, rt reflect.Type, name string, inProgress map[reflect.Type]*decOp) (*decOp, int) {
- ut := userType(rt)
- // If the type implements GobEncoder, we handle it without further processing.
- if ut.externalDec != 0 {
- return dec.gobDecodeOpFor(ut)
- }
-
- // If this type is already in progress, it's a recursive type (e.g. map[string]*T).
- // Return the pointer to the op we're already building.
- if opPtr := inProgress[rt]; opPtr != nil {
- return opPtr, ut.indir
- }
- typ := ut.base
- indir := ut.indir
- var op decOp
- k := typ.Kind()
- if int(k) < len(decOpTable) {
- op = decOpTable[k]
- }
- if op == nil {
- inProgress[rt] = &op
- // Special cases
- switch t := typ; t.Kind() {
- case reflect.Array:
- name = "element of " + name
- elemId := dec.wireType[wireId].ArrayT.Elem
- elemOp, elemIndir := dec.decOpFor(elemId, t.Elem(), name, inProgress)
- ovfl := overflow(name)
- op = func(i *decInstr, state *decoderState, p unsafe.Pointer) {
- state.dec.decodeArray(t, state, p, *elemOp, t.Elem().Size(), t.Len(), i.indir, elemIndir, ovfl)
- }
-
- case reflect.Map:
- keyId := dec.wireType[wireId].MapT.Key
- elemId := dec.wireType[wireId].MapT.Elem
- keyOp, keyIndir := dec.decOpFor(keyId, t.Key(), "key of "+name, inProgress)
- elemOp, elemIndir := dec.decOpFor(elemId, t.Elem(), "element of "+name, inProgress)
- ovfl := overflow(name)
- op = func(i *decInstr, state *decoderState, p unsafe.Pointer) {
- state.dec.decodeMap(t, state, p, *keyOp, *elemOp, i.indir, keyIndir, elemIndir, ovfl)
- }
-
- case reflect.Slice:
- name = "element of " + name
- if t.Elem().Kind() == reflect.Uint8 {
- op = decUint8Slice
- break
- }
- var elemId typeId
- if tt, ok := builtinIdToType[wireId]; ok {
- elemId = tt.(*sliceType).Elem
- } else {
- elemId = dec.wireType[wireId].SliceT.Elem
- }
- elemOp, elemIndir := dec.decOpFor(elemId, t.Elem(), name, inProgress)
- ovfl := overflow(name)
- op = func(i *decInstr, state *decoderState, p unsafe.Pointer) {
- state.dec.decodeSlice(t, state, p, *elemOp, t.Elem().Size(), i.indir, elemIndir, ovfl)
- }
-
- case reflect.Struct:
- // Generate a closure that calls out to the engine for the nested type.
- enginePtr, err := dec.getDecEnginePtr(wireId, userType(typ))
- if err != nil {
- error_(err)
- }
- op = func(i *decInstr, state *decoderState, p unsafe.Pointer) {
- // indirect through enginePtr to delay evaluation for recursive structs.
- dec.decodeStruct(*enginePtr, userType(typ), p, i.indir)
- }
- case reflect.Interface:
- op = func(i *decInstr, state *decoderState, p unsafe.Pointer) {
- state.dec.decodeInterface(t, state, p, i.indir)
- }
- }
- }
- if op == nil {
- errorf("decode can't handle type %s", rt)
- }
- return &op, indir
-}
-
-// decIgnoreOpFor returns the decoding op for a field that has no destination.
-func (dec *Decoder) decIgnoreOpFor(wireId typeId) decOp {
- op, ok := decIgnoreOpMap[wireId]
- if !ok {
- if wireId == tInterface {
- // Special case because it's a method: the ignored item might
- // define types and we need to record their state in the decoder.
- op = func(i *decInstr, state *decoderState, p unsafe.Pointer) {
- state.dec.ignoreInterface(state)
- }
- return op
- }
- // Special cases
- wire := dec.wireType[wireId]
- switch {
- case wire == nil:
- errorf("bad data: undefined type %s", wireId.string())
- case wire.ArrayT != nil:
- elemId := wire.ArrayT.Elem
- elemOp := dec.decIgnoreOpFor(elemId)
- op = func(i *decInstr, state *decoderState, p unsafe.Pointer) {
- state.dec.ignoreArray(state, elemOp, wire.ArrayT.Len)
- }
-
- case wire.MapT != nil:
- keyId := dec.wireType[wireId].MapT.Key
- elemId := dec.wireType[wireId].MapT.Elem
- keyOp := dec.decIgnoreOpFor(keyId)
- elemOp := dec.decIgnoreOpFor(elemId)
- op = func(i *decInstr, state *decoderState, p unsafe.Pointer) {
- state.dec.ignoreMap(state, keyOp, elemOp)
- }
-
- case wire.SliceT != nil:
- elemId := wire.SliceT.Elem
- elemOp := dec.decIgnoreOpFor(elemId)
- op = func(i *decInstr, state *decoderState, p unsafe.Pointer) {
- state.dec.ignoreSlice(state, elemOp)
- }
-
- case wire.StructT != nil:
- // Generate a closure that calls out to the engine for the nested type.
- enginePtr, err := dec.getIgnoreEnginePtr(wireId)
- if err != nil {
- error_(err)
- }
- op = func(i *decInstr, state *decoderState, p unsafe.Pointer) {
- // indirect through enginePtr to delay evaluation for recursive structs
- state.dec.ignoreStruct(*enginePtr)
- }
-
- case wire.GobEncoderT != nil, wire.BinaryMarshalerT != nil, wire.TextMarshalerT != nil:
- op = func(i *decInstr, state *decoderState, p unsafe.Pointer) {
- state.dec.ignoreGobDecoder(state)
- }
- }
- }
- if op == nil {
- errorf("bad data: ignore can't handle type %s", wireId.string())
- }
- return op
-}
-
-// gobDecodeOpFor returns the op for a type that is known to implement
-// GobDecoder.
-func (dec *Decoder) gobDecodeOpFor(ut *userTypeInfo) (*decOp, int) {
- rcvrType := ut.user
- if ut.decIndir == -1 {
- rcvrType = reflect.PtrTo(rcvrType)
- } else if ut.decIndir > 0 {
- for i := int8(0); i < ut.decIndir; i++ {
- rcvrType = rcvrType.Elem()
- }
- }
- var op decOp
- op = func(i *decInstr, state *decoderState, p unsafe.Pointer) {
- // Caller has gotten us to within one indirection of our value.
- if i.indir > 0 {
- if *(*unsafe.Pointer)(p) == nil {
- *(*unsafe.Pointer)(p) = unsafe.Pointer(reflect.New(ut.base).Pointer())
- }
- }
- // Now p is a pointer to the base type. Do we need to climb out to
- // get to the receiver type?
- var v reflect.Value
- if ut.decIndir == -1 {
- v = reflect.NewAt(rcvrType, unsafe.Pointer(&p)).Elem()
- } else {
- v = reflect.NewAt(rcvrType, p).Elem()
- }
- state.dec.decodeGobDecoder(ut, state, v)
- }
- return &op, int(ut.indir)
-
-}
-
-// compatibleType asks: Are these two gob Types compatible?
-// Answers the question for basic types, arrays, maps and slices, plus
-// GobEncoder/Decoder pairs.
-// Structs are considered ok; fields will be checked later.
-func (dec *Decoder) compatibleType(fr reflect.Type, fw typeId, inProgress map[reflect.Type]typeId) bool {
- if rhs, ok := inProgress[fr]; ok {
- return rhs == fw
- }
- inProgress[fr] = fw
- ut := userType(fr)
- wire, ok := dec.wireType[fw]
- // If wire was encoded with an encoding method, fr must have that method.
- // And if not, it must not.
- // At most one of the booleans in ut is set.
- // We could possibly relax this constraint in the future in order to
- // choose the decoding method using the data in the wireType.
- // The parentheses look odd but are correct.
- if (ut.externalDec == xGob) != (ok && wire.GobEncoderT != nil) ||
- (ut.externalDec == xBinary) != (ok && wire.BinaryMarshalerT != nil) ||
- (ut.externalDec == xText) != (ok && wire.TextMarshalerT != nil) {
- return false
- }
- if ut.externalDec != 0 { // This test trumps all others.
- return true
- }
- switch t := ut.base; t.Kind() {
- default:
- // chan, etc: cannot handle.
- return false
- case reflect.Bool:
- return fw == tBool
- case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
- return fw == tInt
- case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
- return fw == tUint
- case reflect.Float32, reflect.Float64:
- return fw == tFloat
- case reflect.Complex64, reflect.Complex128:
- return fw == tComplex
- case reflect.String:
- return fw == tString
- case reflect.Interface:
- return fw == tInterface
- case reflect.Array:
- if !ok || wire.ArrayT == nil {
- return false
- }
- array := wire.ArrayT
- return t.Len() == array.Len && dec.compatibleType(t.Elem(), array.Elem, inProgress)
- case reflect.Map:
- if !ok || wire.MapT == nil {
- return false
- }
- MapType := wire.MapT
- return dec.compatibleType(t.Key(), MapType.Key, inProgress) && dec.compatibleType(t.Elem(), MapType.Elem, inProgress)
- case reflect.Slice:
- // Is it an array of bytes?
- if t.Elem().Kind() == reflect.Uint8 {
- return fw == tBytes
- }
- // Extract and compare element types.
- var sw *sliceType
- if tt, ok := builtinIdToType[fw]; ok {
- sw, _ = tt.(*sliceType)
- } else if wire != nil {
- sw = wire.SliceT
- }
- elem := userType(t.Elem()).base
- return sw != nil && dec.compatibleType(elem, sw.Elem, inProgress)
- case reflect.Struct:
- return true
- }
-}
-
-// typeString returns a human-readable description of the type identified by remoteId.
-func (dec *Decoder) typeString(remoteId typeId) string {
- if t := idToType[remoteId]; t != nil {
- // globally known type.
- return t.string()
- }
- return dec.wireType[remoteId].string()
-}
-
-// compileSingle compiles the decoder engine for a non-struct top-level value, including
-// GobDecoders.
-func (dec *Decoder) compileSingle(remoteId typeId, ut *userTypeInfo) (engine *decEngine, err error) {
- rt := ut.user
- engine = new(decEngine)
- engine.instr = make([]decInstr, 1) // one item
- name := rt.String() // best we can do
- if !dec.compatibleType(rt, remoteId, make(map[reflect.Type]typeId)) {
- remoteType := dec.typeString(remoteId)
- // Common confusing case: local interface type, remote concrete type.
- if ut.base.Kind() == reflect.Interface && remoteId != tInterface {
- return nil, errors.New("gob: local interface type " + name + " can only be decoded from remote interface type; received concrete type " + remoteType)
- }
- return nil, errors.New("gob: decoding into local type " + name + ", received remote type " + remoteType)
- }
- op, indir := dec.decOpFor(remoteId, rt, name, make(map[reflect.Type]*decOp))
- ovfl := errors.New(`value for "` + name + `" out of range`)
- engine.instr[singletonField] = decInstr{*op, singletonField, indir, 0, ovfl}
- engine.numInstr = 1
- return
-}
-
-// compileIgnoreSingle compiles the decoder engine for a non-struct top-level value that will be discarded.
-func (dec *Decoder) compileIgnoreSingle(remoteId typeId) (engine *decEngine, err error) {
- engine = new(decEngine)
- engine.instr = make([]decInstr, 1) // one item
- op := dec.decIgnoreOpFor(remoteId)
- ovfl := overflow(dec.typeString(remoteId))
- engine.instr[0] = decInstr{op, 0, 0, 0, ovfl}
- engine.numInstr = 1
- return
-}
-
-// compileDec compiles the decoder engine for a value. If the value is not a struct,
-// it calls out to compileSingle.
-func (dec *Decoder) compileDec(remoteId typeId, ut *userTypeInfo) (engine *decEngine, err error) {
- rt := ut.base
- srt := rt
- if srt.Kind() != reflect.Struct || ut.externalDec != 0 {
- return dec.compileSingle(remoteId, ut)
- }
- var wireStruct *structType
- // Builtin types can come from global pool; the rest must be defined by the decoder.
- // Also we know we're decoding a struct now, so the client must have sent one.
- if t, ok := builtinIdToType[remoteId]; ok {
- wireStruct, _ = t.(*structType)
- } else {
- wire := dec.wireType[remoteId]
- if wire == nil {
- error_(errBadType)
- }
- wireStruct = wire.StructT
- }
- if wireStruct == nil {
- errorf("type mismatch in decoder: want struct type %s; got non-struct", rt)
- }
- engine = new(decEngine)
- engine.instr = make([]decInstr, len(wireStruct.Field))
- seen := make(map[reflect.Type]*decOp)
- // Loop over the fields of the wire type.
- for fieldnum := 0; fieldnum < len(wireStruct.Field); fieldnum++ {
- wireField := wireStruct.Field[fieldnum]
- if wireField.Name == "" {
- errorf("empty name for remote field of type %s", wireStruct.Name)
- }
- ovfl := overflow(wireField.Name)
- // Find the field of the local type with the same name.
- localField, present := srt.FieldByName(wireField.Name)
- // TODO(r): anonymous names
- if !present || !isExported(wireField.Name) {
- op := dec.decIgnoreOpFor(wireField.Id)
- engine.instr[fieldnum] = decInstr{op, fieldnum, 0, 0, ovfl}
- continue
- }
- if !dec.compatibleType(localField.Type, wireField.Id, make(map[reflect.Type]typeId)) {
- errorf("wrong type (%s) for received field %s.%s", localField.Type, wireStruct.Name, wireField.Name)
- }
- op, indir := dec.decOpFor(wireField.Id, localField.Type, localField.Name, seen)
- engine.instr[fieldnum] = decInstr{*op, fieldnum, indir, uintptr(localField.Offset), ovfl}
- engine.numInstr++
- }
- return
-}
-
-// getDecEnginePtr returns the engine for the specified type.
-func (dec *Decoder) getDecEnginePtr(remoteId typeId, ut *userTypeInfo) (enginePtr **decEngine, err error) {
- rt := ut.user
- decoderMap, ok := dec.decoderCache[rt]
- if !ok {
- decoderMap = make(map[typeId]**decEngine)
- dec.decoderCache[rt] = decoderMap
- }
- if enginePtr, ok = decoderMap[remoteId]; !ok {
- // To handle recursive types, mark this engine as underway before compiling.
- enginePtr = new(*decEngine)
- decoderMap[remoteId] = enginePtr
- *enginePtr, err = dec.compileDec(remoteId, ut)
- if err != nil {
- delete(decoderMap, remoteId)
- }
- }
- return
-}
-
-// emptyStruct is the type we compile into when ignoring a struct value.
-type emptyStruct struct{}
-
-var emptyStructType = reflect.TypeOf(emptyStruct{})
-
-// getDecEnginePtr returns the engine for the specified type when the value is to be discarded.
-func (dec *Decoder) getIgnoreEnginePtr(wireId typeId) (enginePtr **decEngine, err error) {
- var ok bool
- if enginePtr, ok = dec.ignorerCache[wireId]; !ok {
- // To handle recursive types, mark this engine as underway before compiling.
- enginePtr = new(*decEngine)
- dec.ignorerCache[wireId] = enginePtr
- wire := dec.wireType[wireId]
- if wire != nil && wire.StructT != nil {
- *enginePtr, err = dec.compileDec(wireId, userType(emptyStructType))
- } else {
- *enginePtr, err = dec.compileIgnoreSingle(wireId)
- }
- if err != nil {
- delete(dec.ignorerCache, wireId)
- }
- }
- return
-}
-
-// decodeValue decodes the data stream representing a value and stores it in val.
-func (dec *Decoder) decodeValue(wireId typeId, val reflect.Value) {
- defer catchError(&dec.err)
- // If the value is nil, it means we should just ignore this item.
- if !val.IsValid() {
- dec.decodeIgnoredValue(wireId)
- return
- }
- // Dereference down to the underlying type.
- ut := userType(val.Type())
- base := ut.base
- var enginePtr **decEngine
- enginePtr, dec.err = dec.getDecEnginePtr(wireId, ut)
- if dec.err != nil {
- return
- }
- engine := *enginePtr
- if st := base; st.Kind() == reflect.Struct && ut.externalDec == 0 {
- if engine.numInstr == 0 && st.NumField() > 0 &&
- dec.wireType[wireId] != nil && len(dec.wireType[wireId].StructT.Field) > 0 {
- name := base.Name()
- errorf("type mismatch: no fields matched compiling decoder for %s", name)
- }
- dec.decodeStruct(engine, ut, unsafeAddr(val), ut.indir)
- } else {
- dec.decodeSingle(engine, ut, unsafeAddr(val))
- }
-}
-
-// decodeIgnoredValue decodes the data stream representing a value of the specified type and discards it.
-func (dec *Decoder) decodeIgnoredValue(wireId typeId) {
- var enginePtr **decEngine
- enginePtr, dec.err = dec.getIgnoreEnginePtr(wireId)
- if dec.err != nil {
- return
- }
- wire := dec.wireType[wireId]
- if wire != nil && wire.StructT != nil {
- dec.ignoreStruct(*enginePtr)
- } else {
- dec.ignoreSingle(*enginePtr)
- }
-}
-
-func init() {
- var iop, uop decOp
- switch reflect.TypeOf(int(0)).Bits() {
- case 32:
- iop = decInt32
- uop = decUint32
- case 64:
- iop = decInt64
- uop = decUint64
- default:
- panic("gob: unknown size of int/uint")
- }
- decOpTable[reflect.Int] = iop
- decOpTable[reflect.Uint] = uop
-
- // Finally uintptr
- switch reflect.TypeOf(uintptr(0)).Bits() {
- case 32:
- uop = decUint32
- case 64:
- uop = decUint64
- default:
- panic("gob: unknown size of uintptr")
- }
- decOpTable[reflect.Uintptr] = uop
-}
-
-// Gob assumes it can call UnsafeAddr on any Value
-// in order to get a pointer it can copy data from.
-// Values that have just been created and do not point
-// into existing structs or slices cannot be addressed,
-// so simulate it by returning a pointer to a copy.
-// Each call allocates once.
-func unsafeAddr(v reflect.Value) unsafe.Pointer {
- if v.CanAddr() {
- return unsafe.Pointer(v.UnsafeAddr())
- }
- x := reflect.New(v.Type()).Elem()
- x.Set(v)
- return unsafe.Pointer(x.UnsafeAddr())
-}
-
-// Gob depends on being able to take the address
-// of zeroed Values it creates, so use this wrapper instead
-// of the standard reflect.Zero.
-// Each call allocates once.
-func allocValue(t reflect.Type) reflect.Value {
- return reflect.New(t).Elem()
-}
generated by cgit v1.2.3 (git 2.39.1) at 2025-04-30 12:09:00 +0000