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6f05ff1 Feb 23, 2018
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@ugorji @client9 @allenluce
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// Copyright (c) 2012-2018 Ugorji Nwoke. All rights reserved.
// Use of this source code is governed by a MIT license found in the LICENSE file.
package codec
import (
"bufio"
"encoding"
"errors"
"fmt"
"io"
"reflect"
"sort"
"strconv"
"sync"
"time"
)
const defEncByteBufSize = 1 << 6 // 4:16, 6:64, 8:256, 10:1024
var errEncoderNotInitialized = errors.New("Encoder not initialized")
// encWriter abstracts writing to a byte array or to an io.Writer.
type encWriter interface {
writeb([]byte)
writestr(string)
writen1(byte)
writen2(byte, byte)
atEndOfEncode()
}
// encDriver abstracts the actual codec (binc vs msgpack, etc)
type encDriver interface {
EncodeNil()
EncodeInt(i int64)
EncodeUint(i uint64)
EncodeBool(b bool)
EncodeFloat32(f float32)
EncodeFloat64(f float64)
// encodeExtPreamble(xtag byte, length int)
EncodeRawExt(re *RawExt, e *Encoder)
EncodeExt(v interface{}, xtag uint64, ext Ext, e *Encoder)
EncodeString(c charEncoding, v string)
// EncodeSymbol(v string)
EncodeStringBytes(c charEncoding, v []byte)
EncodeTime(time.Time)
//encBignum(f *big.Int)
//encStringRunes(c charEncoding, v []rune)
WriteArrayStart(length int)
WriteArrayElem()
WriteArrayEnd()
WriteMapStart(length int)
WriteMapElemKey()
WriteMapElemValue()
WriteMapEnd()
reset()
atEndOfEncode()
}
type ioEncStringWriter interface {
WriteString(s string) (n int, err error)
}
type encDriverAsis interface {
EncodeAsis(v []byte)
}
type encDriverNoopContainerWriter struct{}
func (encDriverNoopContainerWriter) WriteArrayStart(length int) {}
func (encDriverNoopContainerWriter) WriteArrayElem() {}
func (encDriverNoopContainerWriter) WriteArrayEnd() {}
func (encDriverNoopContainerWriter) WriteMapStart(length int) {}
func (encDriverNoopContainerWriter) WriteMapElemKey() {}
func (encDriverNoopContainerWriter) WriteMapElemValue() {}
func (encDriverNoopContainerWriter) WriteMapEnd() {}
func (encDriverNoopContainerWriter) atEndOfEncode() {}
type encDriverTrackContainerWriter struct {
c containerState
}
func (e *encDriverTrackContainerWriter) WriteArrayStart(length int) { e.c = containerArrayStart }
func (e *encDriverTrackContainerWriter) WriteArrayElem() { e.c = containerArrayElem }
func (e *encDriverTrackContainerWriter) WriteArrayEnd() { e.c = containerArrayEnd }
func (e *encDriverTrackContainerWriter) WriteMapStart(length int) { e.c = containerMapStart }
func (e *encDriverTrackContainerWriter) WriteMapElemKey() { e.c = containerMapKey }
func (e *encDriverTrackContainerWriter) WriteMapElemValue() { e.c = containerMapValue }
func (e *encDriverTrackContainerWriter) WriteMapEnd() { e.c = containerMapEnd }
func (e *encDriverTrackContainerWriter) atEndOfEncode() {}
// type ioEncWriterWriter interface {
// WriteByte(c byte) error
// WriteString(s string) (n int, err error)
// Write(p []byte) (n int, err error)
// }
// EncodeOptions captures configuration options during encode.
type EncodeOptions struct {
// WriterBufferSize is the size of the buffer used when writing.
//
// if > 0, we use a smart buffer internally for performance purposes.
WriterBufferSize int
// ChanRecvTimeout is the timeout used when selecting from a chan.
//
// Configuring this controls how we receive from a chan during the encoding process.
// - If ==0, we only consume the elements currently available in the chan.
// - if <0, we consume until the chan is closed.
// - If >0, we consume until this timeout.
ChanRecvTimeout time.Duration
// StructToArray specifies to encode a struct as an array, and not as a map
StructToArray bool
// Canonical representation means that encoding a value will always result in the same
// sequence of bytes.
//
// This only affects maps, as the iteration order for maps is random.
//
// The implementation MAY use the natural sort order for the map keys if possible:
//
// - If there is a natural sort order (ie for number, bool, string or []byte keys),
// then the map keys are first sorted in natural order and then written
// with corresponding map values to the strema.
// - If there is no natural sort order, then the map keys will first be
// encoded into []byte, and then sorted,
// before writing the sorted keys and the corresponding map values to the stream.
//
Canonical bool
// CheckCircularRef controls whether we check for circular references
// and error fast during an encode.
//
// If enabled, an error is received if a pointer to a struct
// references itself either directly or through one of its fields (iteratively).
//
// This is opt-in, as there may be a performance hit to checking circular references.
CheckCircularRef bool
// RecursiveEmptyCheck controls whether we descend into interfaces, structs and pointers
// when checking if a value is empty.
//
// Note that this may make OmitEmpty more expensive, as it incurs a lot more reflect calls.
RecursiveEmptyCheck bool
// Raw controls whether we encode Raw values.
// This is a "dangerous" option and must be explicitly set.
// If set, we blindly encode Raw values as-is, without checking
// if they are a correct representation of a value in that format.
// If unset, we error out.
Raw bool
// // AsSymbols defines what should be encoded as symbols.
// //
// // Encoding as symbols can reduce the encoded size significantly.
// //
// // However, during decoding, each string to be encoded as a symbol must
// // be checked to see if it has been seen before. Consequently, encoding time
// // will increase if using symbols, because string comparisons has a clear cost.
// //
// // Sample values:
// // AsSymbolNone
// // AsSymbolAll
// // AsSymbolMapStringKeys
// // AsSymbolMapStringKeysFlag | AsSymbolStructFieldNameFlag
// AsSymbols AsSymbolFlag
}
// ---------------------------------------------
// ioEncWriter implements encWriter and can write to an io.Writer implementation
type ioEncWriter struct {
w io.Writer
ww io.Writer
bw io.ByteWriter
sw ioEncStringWriter
fw ioFlusher
b [8]byte
}
func (z *ioEncWriter) WriteByte(b byte) (err error) {
z.b[0] = b
_, err = z.w.Write(z.b[:1])
return
}
func (z *ioEncWriter) WriteString(s string) (n int, err error) {
return z.w.Write(bytesView(s))
}
func (z *ioEncWriter) writeb(bs []byte) {
if _, err := z.ww.Write(bs); err != nil {
panic(err)
}
}
func (z *ioEncWriter) writestr(s string) {
if _, err := z.sw.WriteString(s); err != nil {
panic(err)
}
}
func (z *ioEncWriter) writen1(b byte) {
if err := z.bw.WriteByte(b); err != nil {
panic(err)
}
}
func (z *ioEncWriter) writen2(b1, b2 byte) {
var err error
if err = z.bw.WriteByte(b1); err == nil {
if err = z.bw.WriteByte(b2); err == nil {
return
}
}
panic(err)
}
// func (z *ioEncWriter) writen5(b1, b2, b3, b4, b5 byte) {
// z.b[0], z.b[1], z.b[2], z.b[3], z.b[4] = b1, b2, b3, b4, b5
// if _, err := z.ww.Write(z.b[:5]); err != nil {
// panic(err)
// }
// }
func (z *ioEncWriter) atEndOfEncode() {
if z.fw != nil {
if err := z.fw.Flush(); err != nil {
panic(err)
}
}
}
// ---------------------------------------------
// bytesEncAppender implements encWriter and can write to an byte slice.
type bytesEncAppender struct {
b []byte
out *[]byte
}
func (z *bytesEncAppender) writeb(s []byte) {
z.b = append(z.b, s...)
}
func (z *bytesEncAppender) writestr(s string) {
z.b = append(z.b, s...)
}
func (z *bytesEncAppender) writen1(b1 byte) {
z.b = append(z.b, b1)
}
func (z *bytesEncAppender) writen2(b1, b2 byte) {
z.b = append(z.b, b1, b2)
}
func (z *bytesEncAppender) atEndOfEncode() {
*(z.out) = z.b
}
func (z *bytesEncAppender) reset(in []byte, out *[]byte) {
z.b = in[:0]
z.out = out
}
// ---------------------------------------------
func (e *Encoder) rawExt(f *codecFnInfo, rv reflect.Value) {
e.e.EncodeRawExt(rv2i(rv).(*RawExt), e)
}
func (e *Encoder) ext(f *codecFnInfo, rv reflect.Value) {
e.e.EncodeExt(rv2i(rv), f.xfTag, f.xfFn, e)
}
func (e *Encoder) selferMarshal(f *codecFnInfo, rv reflect.Value) {
rv2i(rv).(Selfer).CodecEncodeSelf(e)
}
func (e *Encoder) binaryMarshal(f *codecFnInfo, rv reflect.Value) {
bs, fnerr := rv2i(rv).(encoding.BinaryMarshaler).MarshalBinary()
e.marshal(bs, fnerr, false, cRAW)
}
func (e *Encoder) textMarshal(f *codecFnInfo, rv reflect.Value) {
bs, fnerr := rv2i(rv).(encoding.TextMarshaler).MarshalText()
e.marshal(bs, fnerr, false, cUTF8)
}
func (e *Encoder) jsonMarshal(f *codecFnInfo, rv reflect.Value) {
bs, fnerr := rv2i(rv).(jsonMarshaler).MarshalJSON()
e.marshal(bs, fnerr, true, cUTF8)
}
func (e *Encoder) raw(f *codecFnInfo, rv reflect.Value) {
e.rawBytes(rv2i(rv).(Raw))
}
func (e *Encoder) kInvalid(f *codecFnInfo, rv reflect.Value) {
e.e.EncodeNil()
}
func (e *Encoder) kErr(f *codecFnInfo, rv reflect.Value) {
e.errorf("unsupported kind %s, for %#v", rv.Kind(), rv)
}
func (e *Encoder) kSlice(f *codecFnInfo, rv reflect.Value) {
ti := f.ti
ee := e.e
// array may be non-addressable, so we have to manage with care
// (don't call rv.Bytes, rv.Slice, etc).
// E.g. type struct S{B [2]byte};
// Encode(S{}) will bomb on "panic: slice of unaddressable array".
if f.seq != seqTypeArray {
if rv.IsNil() {
ee.EncodeNil()
return
}
// If in this method, then there was no extension function defined.
// So it's okay to treat as []byte.
if ti.rtid == uint8SliceTypId {
ee.EncodeStringBytes(cRAW, rv.Bytes())
return
}
}
if f.seq == seqTypeChan && ti.chandir&uint8(reflect.RecvDir) == 0 {
e.errorf("send-only channel cannot be encoded")
}
elemsep := e.esep
rtelem := ti.elem
rtelemIsByte := uint8TypId == rt2id(rtelem) // NOT rtelem.Kind() == reflect.Uint8
var l int
// if a slice, array or chan of bytes, treat specially
if rtelemIsByte {
switch f.seq {
case seqTypeSlice:
ee.EncodeStringBytes(cRAW, rv.Bytes())
case seqTypeArray:
l = rv.Len()
if rv.CanAddr() {
ee.EncodeStringBytes(cRAW, rv.Slice(0, l).Bytes())
} else {
var bs []byte
if l <= cap(e.b) {
bs = e.b[:l]
} else {
bs = make([]byte, l)
}
reflect.Copy(reflect.ValueOf(bs), rv)
ee.EncodeStringBytes(cRAW, bs)
}
case seqTypeChan:
// do not use range, so that the number of elements encoded
// does not change, and encoding does not hang waiting on someone to close chan.
// for b := range rv2i(rv).(<-chan byte) { bs = append(bs, b) }
// ch := rv2i(rv).(<-chan byte) // fix error - that this is a chan byte, not a <-chan byte.
if rv.IsNil() {
ee.EncodeNil()
break
}
bs := e.b[:0]
irv := rv2i(rv)
ch, ok := irv.(<-chan byte)
if !ok {
ch = irv.(chan byte)
}
L1:
switch timeout := e.h.ChanRecvTimeout; {
case timeout == 0: // only consume available
for {
select {
case b := <-ch:
bs = append(bs, b)
default:
break L1
}
}
case timeout > 0: // consume until timeout
tt := time.NewTimer(timeout)
for {
select {
case b := <-ch:
bs = append(bs, b)
case <-tt.C:
// close(tt.C)
break L1
}
}
default: // consume until close
for b := range ch {
bs = append(bs, b)
}
}
ee.EncodeStringBytes(cRAW, bs)
}
return
}
// if chan, consume chan into a slice, and work off that slice.
var rvcs reflect.Value
if f.seq == seqTypeChan {
rvcs = reflect.Zero(reflect.SliceOf(rtelem))
timeout := e.h.ChanRecvTimeout
if timeout < 0 { // consume until close
for {
recv, recvOk := rv.Recv()
if !recvOk {
break
}
rvcs = reflect.Append(rvcs, recv)
}
} else {
cases := make([]reflect.SelectCase, 2)
cases[0] = reflect.SelectCase{Dir: reflect.SelectRecv, Chan: rv}
if timeout == 0 {
cases[1] = reflect.SelectCase{Dir: reflect.SelectDefault}
} else {
tt := time.NewTimer(timeout)
cases[1] = reflect.SelectCase{Dir: reflect.SelectRecv, Chan: reflect.ValueOf(tt.C)}
}
for {
chosen, recv, recvOk := reflect.Select(cases)
if chosen == 1 || !recvOk {
break
}
rvcs = reflect.Append(rvcs, recv)
}
}
rv = rvcs // TODO: ensure this doesn't mess up anywhere that rv of kind chan is expected
}
l = rv.Len()
if ti.mbs {
if l%2 == 1 {
e.errorf("mapBySlice requires even slice length, but got %v", l)
return
}
ee.WriteMapStart(l / 2)
} else {
ee.WriteArrayStart(l)
}
if l > 0 {
var fn *codecFn
for rtelem.Kind() == reflect.Ptr {
rtelem = rtelem.Elem()
}
// if kind is reflect.Interface, do not pre-determine the
// encoding type, because preEncodeValue may break it down to
// a concrete type and kInterface will bomb.
if rtelem.Kind() != reflect.Interface {
fn = e.cfer().get(rtelem, true, true)
}
for j := 0; j < l; j++ {
if elemsep {
if ti.mbs {
if j%2 == 0 {
ee.WriteMapElemKey()
} else {
ee.WriteMapElemValue()
}
} else {
ee.WriteArrayElem()
}
}
e.encodeValue(rv.Index(j), fn, true)
}
}
if ti.mbs {
ee.WriteMapEnd()
} else {
ee.WriteArrayEnd()
}
}
func (e *Encoder) kStructNoOmitempty(f *codecFnInfo, rv reflect.Value) {
fti := f.ti
elemsep := e.esep
tisfi := fti.sfiSrc
toMap := !(fti.toArray || e.h.StructToArray)
if toMap {
tisfi = fti.sfiSort
}
ee := e.e
sfn := structFieldNode{v: rv, update: false}
if toMap {
ee.WriteMapStart(len(tisfi))
if elemsep {
for _, si := range tisfi {
ee.WriteMapElemKey()
// ee.EncodeString(cUTF8, si.encName)
encStructFieldKey(ee, fti.keyType, si.encName)
ee.WriteMapElemValue()
e.encodeValue(sfn.field(si), nil, true)
}
} else {
for _, si := range tisfi {
// ee.EncodeString(cUTF8, si.encName)
encStructFieldKey(ee, fti.keyType, si.encName)
e.encodeValue(sfn.field(si), nil, true)
}
}
ee.WriteMapEnd()
} else {
ee.WriteArrayStart(len(tisfi))
if elemsep {
for _, si := range tisfi {
ee.WriteArrayElem()
e.encodeValue(sfn.field(si), nil, true)
}
} else {
for _, si := range tisfi {
e.encodeValue(sfn.field(si), nil, true)
}
}
ee.WriteArrayEnd()
}
}
func encStructFieldKey(ee encDriver, keyType valueType, s string) {
var m must
// use if-else-if, not switch (which compiles to binary-search)
// since keyType is typically valueTypeString, branch prediction is pretty good.
if keyType == valueTypeString {
ee.EncodeString(cUTF8, s)
} else if keyType == valueTypeInt {
ee.EncodeInt(m.Int(strconv.ParseInt(s, 10, 64)))
} else if keyType == valueTypeUint {
ee.EncodeUint(m.Uint(strconv.ParseUint(s, 10, 64)))
} else if keyType == valueTypeFloat {
ee.EncodeFloat64(m.Float(strconv.ParseFloat(s, 64)))
} else {
ee.EncodeString(cUTF8, s)
}
}
func (e *Encoder) kStruct(f *codecFnInfo, rv reflect.Value) {
fti := f.ti
elemsep := e.esep
tisfi := fti.sfiSrc
toMap := !(fti.toArray || e.h.StructToArray)
// if toMap, use the sorted array. If toArray, use unsorted array (to match sequence in struct)
if toMap {
tisfi = fti.sfiSort
}
newlen := len(fti.sfiSort)
ee := e.e
// Use sync.Pool to reduce allocating slices unnecessarily.
// The cost of sync.Pool is less than the cost of new allocation.
//
// Each element of the array pools one of encStructPool(8|16|32|64).
// It allows the re-use of slices up to 64 in length.
// A performance cost of encoding structs was collecting
// which values were empty and should be omitted.
// We needed slices of reflect.Value and string to collect them.
// This shared pool reduces the amount of unnecessary creation we do.
// The cost is that of locking sometimes, but sync.Pool is efficient
// enough to reduce thread contention.
var spool *sync.Pool
var poolv interface{}
var fkvs []stringRv
// fmt.Printf(">>>>>>>>>>>>>> encode.kStruct: newlen: %d\n", newlen)
if newlen <= 8 {
spool, poolv = pool.stringRv8()
fkvs = poolv.(*[8]stringRv)[:newlen]
} else if newlen <= 16 {
spool, poolv = pool.stringRv16()
fkvs = poolv.(*[16]stringRv)[:newlen]
} else if newlen <= 32 {
spool, poolv = pool.stringRv32()
fkvs = poolv.(*[32]stringRv)[:newlen]
} else if newlen <= 64 {
spool, poolv = pool.stringRv64()
fkvs = poolv.(*[64]stringRv)[:newlen]
} else if newlen <= 128 {
spool, poolv = pool.stringRv128()
fkvs = poolv.(*[128]stringRv)[:newlen]
} else {
fkvs = make([]stringRv, newlen)
}
newlen = 0
var kv stringRv
recur := e.h.RecursiveEmptyCheck
sfn := structFieldNode{v: rv, update: false}
for _, si := range tisfi {
// kv.r = si.field(rv, false)
kv.r = sfn.field(si)
if toMap {
if si.omitEmpty() && isEmptyValue(kv.r, e.h.TypeInfos, recur, recur) {
continue
}
kv.v = si.encName
} else {
// use the zero value.
// if a reference or struct, set to nil (so you do not output too much)
if si.omitEmpty() && isEmptyValue(kv.r, e.h.TypeInfos, recur, recur) {
switch kv.r.Kind() {
case reflect.Struct, reflect.Interface, reflect.Ptr, reflect.Array, reflect.Map, reflect.Slice:
kv.r = reflect.Value{} //encode as nil
}
}
}
fkvs[newlen] = kv
newlen++
}
if toMap {
ee.WriteMapStart(newlen)
if elemsep {
for j := 0; j < newlen; j++ {
kv = fkvs[j]
ee.WriteMapElemKey()
// ee.EncodeString(cUTF8, kv.v)
encStructFieldKey(ee, fti.keyType, kv.v)
ee.WriteMapElemValue()
e.encodeValue(kv.r, nil, true)
}
} else {
for j := 0; j < newlen; j++ {
kv = fkvs[j]
// ee.EncodeString(cUTF8, kv.v)
encStructFieldKey(ee, fti.keyType, kv.v)
e.encodeValue(kv.r, nil, true)
}
}
ee.WriteMapEnd()
} else {
ee.WriteArrayStart(newlen)
if elemsep {
for j := 0; j < newlen; j++ {
ee.WriteArrayElem()
e.encodeValue(fkvs[j].r, nil, true)
}
} else {
for j := 0; j < newlen; j++ {
e.encodeValue(fkvs[j].r, nil, true)
}
}
ee.WriteArrayEnd()
}
// do not use defer. Instead, use explicit pool return at end of function.
// defer has a cost we are trying to avoid.
// If there is a panic and these slices are not returned, it is ok.
if spool != nil {
spool.Put(poolv)
}
}
func (e *Encoder) kMap(f *codecFnInfo, rv reflect.Value) {
ee := e.e
if rv.IsNil() {
ee.EncodeNil()
return
}
l := rv.Len()
ee.WriteMapStart(l)
elemsep := e.esep
if l == 0 {
ee.WriteMapEnd()
return
}
// var asSymbols bool
// determine the underlying key and val encFn's for the map.
// This eliminates some work which is done for each loop iteration i.e.
// rv.Type(), ref.ValueOf(rt).Pointer(), then check map/list for fn.
//
// However, if kind is reflect.Interface, do not pre-determine the
// encoding type, because preEncodeValue may break it down to
// a concrete type and kInterface will bomb.
var keyFn, valFn *codecFn
ti := f.ti
rtkey0 := ti.key
rtkey := rtkey0
rtval0 := ti.elem
rtval := rtval0
// rtkeyid := rt2id(rtkey0)
for rtval.Kind() == reflect.Ptr {
rtval = rtval.Elem()
}
if rtval.Kind() != reflect.Interface {
valFn = e.cfer().get(rtval, true, true)
}
mks := rv.MapKeys()
if e.h.Canonical {
e.kMapCanonical(rtkey, rv, mks, valFn)
ee.WriteMapEnd()
return
}
var keyTypeIsString = stringTypId == rt2id(rtkey0) // rtkeyid
if !keyTypeIsString {
for rtkey.Kind() == reflect.Ptr {
rtkey = rtkey.Elem()
}
if rtkey.Kind() != reflect.Interface {
// rtkeyid = rt2id(rtkey)
keyFn = e.cfer().get(rtkey, true, true)
}
}
// for j, lmks := 0, len(mks); j < lmks; j++ {
for j := range mks {
if elemsep {
ee.WriteMapElemKey()
}
if keyTypeIsString {
ee.EncodeString(cUTF8, mks[j].String())
} else {
e.encodeValue(mks[j], keyFn, true)
}
if elemsep {
ee.WriteMapElemValue()
}
e.encodeValue(rv.MapIndex(mks[j]), valFn, true)
}
ee.WriteMapEnd()
}
func (e *Encoder) kMapCanonical(rtkey reflect.Type, rv reflect.Value, mks []reflect.Value, valFn *codecFn) {
ee := e.e
elemsep := e.esep
// we previously did out-of-band if an extension was registered.
// This is not necessary, as the natural kind is sufficient for ordering.
switch rtkey.Kind() {
case reflect.Bool:
mksv := make([]boolRv, len(mks))
for i, k := range mks {
v := &mksv[i]
v.r = k
v.v = k.Bool()
}
sort.Sort(boolRvSlice(mksv))
for i := range mksv {
if elemsep {
ee.WriteMapElemKey()
}
ee.EncodeBool(mksv[i].v)
if elemsep {
ee.WriteMapElemValue()
}
e.encodeValue(rv.MapIndex(mksv[i].r), valFn, true)
}
case reflect.String:
mksv := make([]stringRv, len(mks))
for i, k := range mks {
v := &mksv[i]
v.r = k
v.v = k.String()
}
sort.Sort(stringRvSlice(mksv))
for i := range mksv {
if elemsep {
ee.WriteMapElemKey()
}
ee.EncodeString(cUTF8, mksv[i].v)
if elemsep {
ee.WriteMapElemValue()
}
e.encodeValue(rv.MapIndex(mksv[i].r), valFn, true)
}
case reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uint, reflect.Uintptr:
mksv := make([]uintRv, len(mks))
for i, k := range mks {
v := &mksv[i]
v.r = k
v.v = k.Uint()
}
sort.Sort(uintRvSlice(mksv))
for i := range mksv {
if elemsep {
ee.WriteMapElemKey()
}
ee.EncodeUint(mksv[i].v)
if elemsep {
ee.WriteMapElemValue()
}
e.encodeValue(rv.MapIndex(mksv[i].r), valFn, true)
}
case reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, reflect.Int:
mksv := make([]intRv, len(mks))
for i, k := range mks {
v := &mksv[i]
v.r = k
v.v = k.Int()
}
sort.Sort(intRvSlice(mksv))
for i := range mksv {
if elemsep {
ee.WriteMapElemKey()
}
ee.EncodeInt(mksv[i].v)
if elemsep {
ee.WriteMapElemValue()
}
e.encodeValue(rv.MapIndex(mksv[i].r), valFn, true)
}
case reflect.Float32:
mksv := make([]floatRv, len(mks))
for i, k := range mks {
v := &mksv[i]
v.r = k
v.v = k.Float()
}
sort.Sort(floatRvSlice(mksv))
for i := range mksv {
if elemsep {
ee.WriteMapElemKey()
}
ee.EncodeFloat32(float32(mksv[i].v))
if elemsep {
ee.WriteMapElemValue()
}
e.encodeValue(rv.MapIndex(mksv[i].r), valFn, true)
}
case reflect.Float64:
mksv := make([]floatRv, len(mks))
for i, k := range mks {
v := &mksv[i]
v.r = k
v.v = k.Float()
}
sort.Sort(floatRvSlice(mksv))
for i := range mksv {
if elemsep {
ee.WriteMapElemKey()
}
ee.EncodeFloat64(mksv[i].v)
if elemsep {
ee.WriteMapElemValue()
}
e.encodeValue(rv.MapIndex(mksv[i].r), valFn, true)
}
case reflect.Struct:
if rv.Type() == timeTyp {
mksv := make([]timeRv, len(mks))
for i, k := range mks {
v := &mksv[i]
v.r = k
v.v = rv2i(k).(time.Time)
}
sort.Sort(timeRvSlice(mksv))
for i := range mksv {
if elemsep {
ee.WriteMapElemKey()
}
ee.EncodeTime(mksv[i].v)
if elemsep {
ee.WriteMapElemValue()
}
e.encodeValue(rv.MapIndex(mksv[i].r), valFn, true)
}
break
}
fallthrough
default:
// out-of-band
// first encode each key to a []byte first, then sort them, then record
var mksv []byte = make([]byte, 0, len(mks)*16) // temporary byte slice for the encoding
e2 := NewEncoderBytes(&mksv, e.hh)
mksbv := make([]bytesRv, len(mks))
for i, k := range mks {
v := &mksbv[i]
l := len(mksv)
e2.MustEncode(k)
v.r = k
v.v = mksv[l:]
}
sort.Sort(bytesRvSlice(mksbv))
for j := range mksbv {
if elemsep {
ee.WriteMapElemKey()
}
e.asis(mksbv[j].v)
if elemsep {
ee.WriteMapElemValue()
}
e.encodeValue(rv.MapIndex(mksbv[j].r), valFn, true)
}
}
}
// // --------------------------------------------------
type encWriterSwitch struct {
wi *ioEncWriter
// wb bytesEncWriter
wb bytesEncAppender
wx bool // if bytes, wx=true
esep bool // whether it has elem separators
isas bool // whether e.as != nil
}
// // TODO: Uncomment after mid-stack inlining enabled in go 1.11
// func (z *encWriterSwitch) writeb(s []byte) {
// if z.wx {
// z.wb.writeb(s)
// } else {
// z.wi.writeb(s)
// }
// }
// func (z *encWriterSwitch) writestr(s string) {
// if z.wx {
// z.wb.writestr(s)
// } else {
// z.wi.writestr(s)
// }
// }
// func (z *encWriterSwitch) writen1(b1 byte) {
// if z.wx {
// z.wb.writen1(b1)
// } else {
// z.wi.writen1(b1)
// }
// }
// func (z *encWriterSwitch) writen2(b1, b2 byte) {
// if z.wx {
// z.wb.writen2(b1, b2)
// } else {
// z.wi.writen2(b1, b2)
// }
// }
// An Encoder writes an object to an output stream in the codec format.
type Encoder struct {
panicHdl
// hopefully, reduce derefencing cost by laying the encWriter inside the Encoder
e encDriver
// NOTE: Encoder shouldn't call it's write methods,
// as the handler MAY need to do some coordination.
w encWriter
h *BasicHandle
bw *bufio.Writer
as encDriverAsis
// ---- cpu cache line boundary?
// ---- cpu cache line boundary?
encWriterSwitch
err error
// ---- cpu cache line boundary?
codecFnPooler
ci set
js bool // here, so that no need to piggy back on *codecFner for this
be bool // here, so that no need to piggy back on *codecFner for this
_ [6]byte // padding
// ---- writable fields during execution --- *try* to keep in sep cache line
// ---- cpu cache line boundary?
// b [scratchByteArrayLen]byte
// _ [cacheLineSize - scratchByteArrayLen]byte // padding
b [cacheLineSize - 0]byte // used for encoding a chan or (non-addressable) array of bytes
}
// NewEncoder returns an Encoder for encoding into an io.Writer.
//
// For efficiency, Users are encouraged to pass in a memory buffered writer
// (eg bufio.Writer, bytes.Buffer).
func NewEncoder(w io.Writer, h Handle) *Encoder {
e := newEncoder(h)
e.Reset(w)
return e
}
// NewEncoderBytes returns an encoder for encoding directly and efficiently
// into a byte slice, using zero-copying to temporary slices.
//
// It will potentially replace the output byte slice pointed to.
// After encoding, the out parameter contains the encoded contents.
func NewEncoderBytes(out *[]byte, h Handle) *Encoder {
e := newEncoder(h)
e.ResetBytes(out)
return e
}
func newEncoder(h Handle) *Encoder {
e := &Encoder{h: h.getBasicHandle(), err: errEncoderNotInitialized}
e.hh = h
e.esep = h.hasElemSeparators()
return e
}
func (e *Encoder) resetCommon() {
if e.e == nil || e.hh.recreateEncDriver(e.e) {
e.e = e.hh.newEncDriver(e)
e.as, e.isas = e.e.(encDriverAsis)
// e.cr, _ = e.e.(containerStateRecv)
}
e.be = e.hh.isBinary()
_, e.js = e.hh.(*JsonHandle)
e.e.reset()
e.err = nil
}
// Reset resets the Encoder with a new output stream.
//
// This accommodates using the state of the Encoder,
// where it has "cached" information about sub-engines.
func (e *Encoder) Reset(w io.Writer) {
if w == nil {
return
}
if e.wi == nil {
e.wi = new(ioEncWriter)
}
var ok bool
e.wx = false
e.wi.w = w
if e.h.WriterBufferSize > 0 {
e.bw = bufio.NewWriterSize(w, e.h.WriterBufferSize)
e.wi.bw = e.bw
e.wi.sw = e.bw
e.wi.fw = e.bw
e.wi.ww = e.bw
} else {
if e.wi.bw, ok = w.(io.ByteWriter); !ok {
e.wi.bw = e.wi
}
if e.wi.sw, ok = w.(ioEncStringWriter); !ok {
e.wi.sw = e.wi
}
e.wi.fw, _ = w.(ioFlusher)
e.wi.ww = w
}
e.w = e.wi
e.resetCommon()
}
// ResetBytes resets the Encoder with a new destination output []byte.
func (e *Encoder) ResetBytes(out *[]byte) {
if out == nil {
return
}
var in []byte
if out != nil {
in = *out
}
if in == nil {
in = make([]byte, defEncByteBufSize)
}
e.wx = true
e.wb.reset(in, out)
e.w = &e.wb
e.resetCommon()
}
// Encode writes an object into a stream.
//
// Encoding can be configured via the struct tag for the fields.
// The key (in the struct tags) that we look at is configurable.
//
// By default, we look up the "codec" key in the struct field's tags,
// and fall bak to the "json" key if "codec" is absent.
// That key in struct field's tag value is the key name,
// followed by an optional comma and options.
//
// To set an option on all fields (e.g. omitempty on all fields), you
// can create a field called _struct, and set flags on it. The options
// which can be set on _struct are:
// - omitempty: so all fields are omitted if empty
// - toarray: so struct is encoded as an array
// - int: so struct key names are encoded as signed integers (instead of strings)
// - uint: so struct key names are encoded as unsigned integers (instead of strings)
// - float: so struct key names are encoded as floats (instead of strings)
// More details on these below.
//
// Struct values "usually" encode as maps. Each exported struct field is encoded unless:
// - the field's tag is "-", OR
// - the field is empty (empty or the zero value) and its tag specifies the "omitempty" option.
//
// When encoding as a map, the first string in the tag (before the comma)
// is the map key string to use when encoding.
// ...
// This key is typically encoded as a string.
// However, there are instances where the encoded stream has mapping keys encoded as numbers.
// For example, some cbor streams have keys as integer codes in the stream, but they should map
// to fields in a structured object. Consequently, a struct is the natural representation in code.
// For these, configure the struct to encode/decode the keys as numbers (instead of string).
// This is done with the int,uint or float option on the _struct field (see above).
//
// However, struct values may encode as arrays. This happens when:
// - StructToArray Encode option is set, OR
// - the tag on the _struct field sets the "toarray" option
// Note that omitempty is ignored when encoding struct values as arrays,
// as an entry must be encoded for each field, to maintain its position.
//
// Values with types that implement MapBySlice are encoded as stream maps.
//
// The empty values (for omitempty option) are false, 0, any nil pointer
// or interface value, and any array, slice, map, or string of length zero.
//
// Anonymous fields are encoded inline except:
// - the struct tag specifies a replacement name (first value)
// - the field is of an interface type
//
// Examples:
//
// // NOTE: 'json:' can be used as struct tag key, in place 'codec:' below.
// type MyStruct struct {
// _struct bool `codec:",omitempty"` //set omitempty for every field
// Field1 string `codec:"-"` //skip this field
// Field2 int `codec:"myName"` //Use key "myName" in encode stream
// Field3 int32 `codec:",omitempty"` //use key "Field3". Omit if empty.
// Field4 bool `codec:"f4,omitempty"` //use key "f4". Omit if empty.
// io.Reader //use key "Reader".
// MyStruct `codec:"my1" //use key "my1".
// MyStruct //inline it
// ...
// }
//
// type MyStruct struct {
// _struct bool `codec:",toarray"` //encode struct as an array
// }
//
// type MyStruct struct {
// _struct bool `codec:",uint"` //encode struct with "unsigned integer" keys
// Field1 string `codec:"1"` //encode Field1 key using: EncodeInt(1)
// Field2 string `codec:"2"` //encode Field2 key using: EncodeInt(2)
// }
//
// The mode of encoding is based on the type of the value. When a value is seen:
// - If a Selfer, call its CodecEncodeSelf method
// - If an extension is registered for it, call that extension function
// - If implements encoding.(Binary|Text|JSON)Marshaler, call Marshal(Binary|Text|JSON) method
// - Else encode it based on its reflect.Kind
//
// Note that struct field names and keys in map[string]XXX will be treated as symbols.
// Some formats support symbols (e.g. binc) and will properly encode the string
// only once in the stream, and use a tag to refer to it thereafter.
func (e *Encoder) Encode(v interface{}) (err error) {
defer e.deferred(&err)
e.MustEncode(v)
return
}
// MustEncode is like Encode, but panics if unable to Encode.
// This provides insight to the code location that triggered the error.
func (e *Encoder) MustEncode(v interface{}) {
if e.err != nil {
panic(e.err)
}
e.encode(v)
e.e.atEndOfEncode()
e.w.atEndOfEncode()
e.alwaysAtEnd()
}
func (e *Encoder) deferred(err1 *error) {
e.alwaysAtEnd()
if recoverPanicToErr {
if x := recover(); x != nil {
panicValToErr(e, x, err1)
panicValToErr(e, x, &e.err)
}
}
}
// func (e *Encoder) alwaysAtEnd() {
// e.codecFnPooler.alwaysAtEnd()
// }
func (e *Encoder) encode(iv interface{}) {
if iv == nil || definitelyNil(iv) {
e.e.EncodeNil()
return
}
if v, ok := iv.(Selfer); ok {
v.CodecEncodeSelf(e)
return
}
// a switch with only concrete types can be optimized.
// consequently, we deal with nil and interfaces outside.
switch v := iv.(type) {
case Raw:
e.rawBytes(v)
case reflect.Value:
e.encodeValue(v, nil, true)
case string:
e.e.EncodeString(cUTF8, v)
case bool:
e.e.EncodeBool(v)
case int:
e.e.EncodeInt(int64(v))
case int8:
e.e.EncodeInt(int64(v))
case int16:
e.e.EncodeInt(int64(v))
case int32:
e.e.EncodeInt(int64(v))
case int64:
e.e.EncodeInt(v)
case uint:
e.e.EncodeUint(uint64(v))
case uint8:
e.e.EncodeUint(uint64(v))
case uint16:
e.e.EncodeUint(uint64(v))
case uint32:
e.e.EncodeUint(uint64(v))
case uint64:
e.e.EncodeUint(v)
case uintptr:
e.e.EncodeUint(uint64(v))
case float32:
e.e.EncodeFloat32(v)
case float64:
e.e.EncodeFloat64(v)
case time.Time:
e.e.EncodeTime(v)
case []uint8:
e.e.EncodeStringBytes(cRAW, v)
case *Raw:
e.rawBytes(*v)
case *string:
e.e.EncodeString(cUTF8, *v)
case *bool:
e.e.EncodeBool(*v)
case *int:
e.e.EncodeInt(int64(*v))
case *int8:
e.e.EncodeInt(int64(*v))
case *int16:
e.e.EncodeInt(int64(*v))
case *int32:
e.e.EncodeInt(int64(*v))
case *int64:
e.e.EncodeInt(*v)
case *uint:
e.e.EncodeUint(uint64(*v))
case *uint8:
e.e.EncodeUint(uint64(*v))
case *uint16:
e.e.EncodeUint(uint64(*v))
case *uint32:
e.e.EncodeUint(uint64(*v))
case *uint64:
e.e.EncodeUint(*v)
case *uintptr:
e.e.EncodeUint(uint64(*v))
case *float32:
e.e.EncodeFloat32(*v)
case *float64:
e.e.EncodeFloat64(*v)
case *time.Time:
e.e.EncodeTime(*v)
case *[]uint8:
e.e.EncodeStringBytes(cRAW, *v)
default:
if !fastpathEncodeTypeSwitch(iv, e) {
// checkfastpath=true (not false), as underlying slice/map type may be fast-path
e.encodeValue(reflect.ValueOf(iv), nil, true)
}
}
}
func (e *Encoder) encodeValue(rv reflect.Value, fn *codecFn, checkFastpath bool) {
// if a valid fn is passed, it MUST BE for the dereferenced type of rv
var sptr uintptr
var rvp reflect.Value
var rvpValid bool
TOP:
switch rv.Kind() {
case reflect.Ptr:
if rv.IsNil() {
e.e.EncodeNil()
return
}
rvpValid = true
rvp = rv
rv = rv.Elem()
if e.h.CheckCircularRef && rv.Kind() == reflect.Struct {
// TODO: Movable pointers will be an issue here. Future problem.
sptr = rv.UnsafeAddr()
break TOP
}
goto TOP
case reflect.Interface:
if rv.IsNil() {
e.e.EncodeNil()
return
}
rv = rv.Elem()
goto TOP
case reflect.Slice, reflect.Map:
if rv.IsNil() {
e.e.EncodeNil()
return
}
case reflect.Invalid, reflect.Func:
e.e.EncodeNil()
return
}
if sptr != 0 && (&e.ci).add(sptr) {
e.errorf("circular reference found: # %d", sptr)
}
if fn == nil {
rt := rv.Type()
// always pass checkCodecSelfer=true, in case T or ****T is passed, where *T is a Selfer
fn = e.cfer().get(rt, checkFastpath, true)
}
if fn.i.addrE {
if rvpValid {
fn.fe(e, &fn.i, rvp)
} else if rv.CanAddr() {
fn.fe(e, &fn.i, rv.Addr())
} else {
rv2 := reflect.New(rv.Type())
rv2.Elem().Set(rv)
fn.fe(e, &fn.i, rv2)
}
} else {
fn.fe(e, &fn.i, rv)
}
if sptr != 0 {
(&e.ci).remove(sptr)
}
}
func (e *Encoder) marshal(bs []byte, fnerr error, asis bool, c charEncoding) {
if fnerr != nil {
panic(fnerr)
}
if bs == nil {
e.e.EncodeNil()
} else if asis {
e.asis(bs)
} else {
e.e.EncodeStringBytes(c, bs)
}
}
func (e *Encoder) asis(v []byte) {
if e.isas {
e.as.EncodeAsis(v)
} else {
e.w.writeb(v)
}
}
func (e *Encoder) rawBytes(vv Raw) {
v := []byte(vv)
if !e.h.Raw {
e.errorf("Raw values cannot be encoded: %v", v)
}
e.asis(v)
}
func (e *Encoder) wrapErrstr(v interface{}, err *error) {
*err = fmt.Errorf("%s encode error: %v", e.hh.Name(), v)
}