// Copyright (c) 2012-2020 Ugorji Nwoke. All rights reserved. // Use of this source code is governed by a MIT license found in the LICENSE file. package codec import ( "encoding" "errors" "io" "reflect" "sort" "strconv" "time" ) // defEncByteBufSize is the default size of []byte used // for bufio buffer or []byte (when nil passed) const defEncByteBufSize = 1 << 10 // 4:16, 6:64, 8:256, 10:1024 var errEncoderNotInitialized = errors.New("Encoder not initialized") // 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) EncodeRawExt(re *RawExt) EncodeExt(v interface{}, basetype reflect.Type, xtag uint64, ext Ext) // EncodeString using cUTF8, honor'ing StringToRaw flag EncodeString(v string) EncodeStringBytesRaw(v []byte) EncodeTime(time.Time) WriteArrayStart(length int) WriteArrayEnd() WriteMapStart(length int) WriteMapEnd() // reset will reset current encoding runtime state, and cached information from the handle reset() encoder() *Encoder driverStateManager } type encDriverContainerTracker interface { WriteArrayElem() WriteMapElemKey() WriteMapElemValue() } type encDriverNoState struct{} func (encDriverNoState) captureState() interface{} { return nil } func (encDriverNoState) reset() {} func (encDriverNoState) resetState() {} func (encDriverNoState) restoreState(v interface{}) {} type encDriverNoopContainerWriter struct{} func (encDriverNoopContainerWriter) WriteArrayStart(length int) {} func (encDriverNoopContainerWriter) WriteArrayEnd() {} func (encDriverNoopContainerWriter) WriteMapStart(length int) {} func (encDriverNoopContainerWriter) WriteMapEnd() {} // encStructFieldObj[Slice] is used for sorting when there are missing fields and canonical flag is set type encStructFieldObj struct { key string rv reflect.Value intf interface{} ascii bool isRv bool } type encStructFieldObjSlice []encStructFieldObj func (p encStructFieldObjSlice) Len() int { return len(p) } func (p encStructFieldObjSlice) Swap(i, j int) { p[uint(i)], p[uint(j)] = p[uint(j)], p[uint(i)] } func (p encStructFieldObjSlice) Less(i, j int) bool { return p[uint(i)].key < p[uint(j)].key } // 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 how we determine whether a value is empty. // // If true, we descend into interfaces and pointers to reursively check if value is empty. // // We *might* check struct fields one by one to see if empty // (if we cannot directly check if a struct value is equal to its zero value). // If so, we honor IsZero, Comparable, IsCodecEmpty(), etc. // Note: This *may* make OmitEmpty more expensive due to the large number of reflect calls. // // If false, we check if the value is equal to its zero value (newly allocated state). 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 // StringToRaw controls how strings are encoded. // // As a go string is just an (immutable) sequence of bytes, // it can be encoded either as raw bytes or as a UTF string. // // By default, strings are encoded as UTF-8. // but can be treated as []byte during an encode. // // Note that things which we know (by definition) to be UTF-8 // are ALWAYS encoded as UTF-8 strings. // These include encoding.TextMarshaler, time.Format calls, struct field names, etc. StringToRaw bool // OptimumSize controls whether we optimize for the smallest size. // // Some formats will use this flag to determine whether to encode // in the smallest size possible, even if it takes slightly longer. // // For example, some formats that support half-floats might check if it is possible // to store a float64 as a half float. Doing this check has a small performance cost, // but the benefit is that the encoded message will be smaller. OptimumSize bool // NoAddressableReadonly controls whether we try to force a non-addressable value // to be addressable so we can call a pointer method on it e.g. for types // that support Selfer, json.Marshaler, etc. // // Use it in the very rare occurrence that your types modify a pointer value when calling // an encode callback function e.g. JsonMarshal, TextMarshal, BinaryMarshal or CodecEncodeSelf. NoAddressableReadonly bool } // --------------------------------------------- func (e *Encoder) rawExt(f *codecFnInfo, rv reflect.Value) { e.e.EncodeRawExt(rv2i(rv).(*RawExt)) } func (e *Encoder) ext(f *codecFnInfo, rv reflect.Value) { e.e.EncodeExt(rv2i(rv), f.ti.rt, f.xfTag, f.xfFn) } 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.marshalRaw(bs, fnerr) } func (e *Encoder) textMarshal(f *codecFnInfo, rv reflect.Value) { bs, fnerr := rv2i(rv).(encoding.TextMarshaler).MarshalText() e.marshalUtf8(bs, fnerr) } func (e *Encoder) jsonMarshal(f *codecFnInfo, rv reflect.Value) { bs, fnerr := rv2i(rv).(jsonMarshaler).MarshalJSON() e.marshalAsis(bs, fnerr) } func (e *Encoder) raw(f *codecFnInfo, rv reflect.Value) { e.rawBytes(rv2i(rv).(Raw)) } func (e *Encoder) encodeComplex64(v complex64) { if imag(v) != 0 { e.errorf("cannot encode complex number: %v, with imaginary values: %v", v, imag(v)) } e.e.EncodeFloat32(real(v)) } func (e *Encoder) encodeComplex128(v complex128) { if imag(v) != 0 { e.errorf("cannot encode complex number: %v, with imaginary values: %v", v, imag(v)) } e.e.EncodeFloat64(real(v)) } func (e *Encoder) kBool(f *codecFnInfo, rv reflect.Value) { e.e.EncodeBool(rvGetBool(rv)) } func (e *Encoder) kTime(f *codecFnInfo, rv reflect.Value) { e.e.EncodeTime(rvGetTime(rv)) } func (e *Encoder) kString(f *codecFnInfo, rv reflect.Value) { e.e.EncodeString(rvGetString(rv)) } func (e *Encoder) kFloat32(f *codecFnInfo, rv reflect.Value) { e.e.EncodeFloat32(rvGetFloat32(rv)) } func (e *Encoder) kFloat64(f *codecFnInfo, rv reflect.Value) { e.e.EncodeFloat64(rvGetFloat64(rv)) } func (e *Encoder) kComplex64(f *codecFnInfo, rv reflect.Value) { e.encodeComplex64(rvGetComplex64(rv)) } func (e *Encoder) kComplex128(f *codecFnInfo, rv reflect.Value) { e.encodeComplex128(rvGetComplex128(rv)) } func (e *Encoder) kInt(f *codecFnInfo, rv reflect.Value) { e.e.EncodeInt(int64(rvGetInt(rv))) } func (e *Encoder) kInt8(f *codecFnInfo, rv reflect.Value) { e.e.EncodeInt(int64(rvGetInt8(rv))) } func (e *Encoder) kInt16(f *codecFnInfo, rv reflect.Value) { e.e.EncodeInt(int64(rvGetInt16(rv))) } func (e *Encoder) kInt32(f *codecFnInfo, rv reflect.Value) { e.e.EncodeInt(int64(rvGetInt32(rv))) } func (e *Encoder) kInt64(f *codecFnInfo, rv reflect.Value) { e.e.EncodeInt(int64(rvGetInt64(rv))) } func (e *Encoder) kUint(f *codecFnInfo, rv reflect.Value) { e.e.EncodeUint(uint64(rvGetUint(rv))) } func (e *Encoder) kUint8(f *codecFnInfo, rv reflect.Value) { e.e.EncodeUint(uint64(rvGetUint8(rv))) } func (e *Encoder) kUint16(f *codecFnInfo, rv reflect.Value) { e.e.EncodeUint(uint64(rvGetUint16(rv))) } func (e *Encoder) kUint32(f *codecFnInfo, rv reflect.Value) { e.e.EncodeUint(uint64(rvGetUint32(rv))) } func (e *Encoder) kUint64(f *codecFnInfo, rv reflect.Value) { e.e.EncodeUint(uint64(rvGetUint64(rv))) } func (e *Encoder) kUintptr(f *codecFnInfo, rv reflect.Value) { e.e.EncodeUint(uint64(rvGetUintptr(rv))) } func (e *Encoder) kErr(f *codecFnInfo, rv reflect.Value) { e.errorf("unsupported kind %s, for %#v", rv.Kind(), rv) } func chanToSlice(rv reflect.Value, rtslice reflect.Type, timeout time.Duration) (rvcs reflect.Value) { rvcs = rvZeroK(rtslice, reflect.Slice) 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) } } return } func (e *Encoder) kSeqFn(rtelem reflect.Type) (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.h.fn(rtelem) } return } func (e *Encoder) kSliceWMbs(rv reflect.Value, ti *typeInfo) { var l = rvLenSlice(rv) if l == 0 { e.mapStart(0) } else { e.haltOnMbsOddLen(l) e.mapStart(l >> 1) // e.mapStart(l / 2) fn := e.kSeqFn(ti.elem) for j := 0; j < l; j++ { if j&1 == 0 { // j%2 == 0 { e.mapElemKey() } else { e.mapElemValue() } e.encodeValue(rvSliceIndex(rv, j, ti), fn) } } e.mapEnd() } func (e *Encoder) kSliceW(rv reflect.Value, ti *typeInfo) { var l = rvLenSlice(rv) e.arrayStart(l) if l > 0 { fn := e.kSeqFn(ti.elem) for j := 0; j < l; j++ { e.arrayElem() e.encodeValue(rvSliceIndex(rv, j, ti), fn) } } e.arrayEnd() } func (e *Encoder) kArrayWMbs(rv reflect.Value, ti *typeInfo) { var l = rv.Len() if l == 0 { e.mapStart(0) } else { e.haltOnMbsOddLen(l) e.mapStart(l >> 1) // e.mapStart(l / 2) fn := e.kSeqFn(ti.elem) for j := 0; j < l; j++ { if j&1 == 0 { // j%2 == 0 { e.mapElemKey() } else { e.mapElemValue() } e.encodeValue(rv.Index(j), fn) } } e.mapEnd() } func (e *Encoder) kArrayW(rv reflect.Value, ti *typeInfo) { var l = rv.Len() e.arrayStart(l) if l > 0 { fn := e.kSeqFn(ti.elem) for j := 0; j < l; j++ { e.arrayElem() e.encodeValue(rv.Index(j), fn) } } e.arrayEnd() } func (e *Encoder) kChan(f *codecFnInfo, rv reflect.Value) { if f.ti.chandir&uint8(reflect.RecvDir) == 0 { e.errorf("send-only channel cannot be encoded") } if !f.ti.mbs && uint8TypId == rt2id(f.ti.elem) { e.kSliceBytesChan(rv) return } rtslice := reflect.SliceOf(f.ti.elem) rv = chanToSlice(rv, rtslice, e.h.ChanRecvTimeout) ti := e.h.getTypeInfo(rt2id(rtslice), rtslice) if f.ti.mbs { e.kSliceWMbs(rv, ti) } else { e.kSliceW(rv, ti) } } func (e *Encoder) kSlice(f *codecFnInfo, rv reflect.Value) { if f.ti.mbs { e.kSliceWMbs(rv, f.ti) } else if f.ti.rtid == uint8SliceTypId || uint8TypId == rt2id(f.ti.elem) { e.e.EncodeStringBytesRaw(rvGetBytes(rv)) } else { e.kSliceW(rv, f.ti) } } func (e *Encoder) kArray(f *codecFnInfo, rv reflect.Value) { if f.ti.mbs { e.kArrayWMbs(rv, f.ti) } else if handleBytesWithinKArray && uint8TypId == rt2id(f.ti.elem) { e.e.EncodeStringBytesRaw(rvGetArrayBytes(rv, []byte{})) } else { e.kArrayW(rv, f.ti) } } func (e *Encoder) kSliceBytesChan(rv reflect.Value) { // 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. bs0 := e.blist.peek(32, true) bs := bs0 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) } } e.e.EncodeStringBytesRaw(bs) e.blist.put(bs) if !byteSliceSameData(bs0, bs) { e.blist.put(bs0) } } func (e *Encoder) kStructSfi(f *codecFnInfo) []*structFieldInfo { if e.h.Canonical { return f.ti.sfi.sorted() } return f.ti.sfi.source() } func (e *Encoder) kStructNoOmitempty(f *codecFnInfo, rv reflect.Value) { var tisfi []*structFieldInfo if f.ti.toArray || e.h.StructToArray { // toArray tisfi = f.ti.sfi.source() e.arrayStart(len(tisfi)) for _, si := range tisfi { e.arrayElem() e.encodeValue(si.path.field(rv), nil) } e.arrayEnd() } else { tisfi = e.kStructSfi(f) e.mapStart(len(tisfi)) keytyp := f.ti.keyType for _, si := range tisfi { e.mapElemKey() e.kStructFieldKey(keytyp, si.path.encNameAsciiAlphaNum, si.encName) e.mapElemValue() e.encodeValue(si.path.field(rv), nil) } e.mapEnd() } } func (e *Encoder) kStructFieldKey(keyType valueType, encNameAsciiAlphaNum bool, encName string) { encStructFieldKey(encName, e.e, e.w(), keyType, encNameAsciiAlphaNum, e.js) } func (e *Encoder) kStruct(f *codecFnInfo, rv reflect.Value) { var newlen int ti := f.ti toMap := !(ti.toArray || e.h.StructToArray) var mf map[string]interface{} if ti.flagMissingFielder { mf = rv2i(rv).(MissingFielder).CodecMissingFields() toMap = true newlen += len(mf) } else if ti.flagMissingFielderPtr { rv2 := e.addrRV(rv, ti.rt, ti.ptr) mf = rv2i(rv2).(MissingFielder).CodecMissingFields() toMap = true newlen += len(mf) } tisfi := ti.sfi.source() newlen += len(tisfi) var fkvs = e.slist.get(newlen)[:newlen] recur := e.h.RecursiveEmptyCheck var kv sfiRv var j int if toMap { newlen = 0 for _, si := range e.kStructSfi(f) { kv.r = si.path.field(rv) if si.path.omitEmpty && isEmptyValue(kv.r, e.h.TypeInfos, recur) { continue } kv.v = si fkvs[newlen] = kv newlen++ } var mf2s []stringIntf if len(mf) > 0 { mf2s = make([]stringIntf, 0, len(mf)) for k, v := range mf { if k == "" { continue } if ti.infoFieldOmitempty && isEmptyValue(reflect.ValueOf(v), e.h.TypeInfos, recur) { continue } mf2s = append(mf2s, stringIntf{k, v}) } } e.mapStart(newlen + len(mf2s)) // When there are missing fields, and Canonical flag is set, // we cannot have the missing fields and struct fields sorted independently. // We have to capture them together and sort as a unit. if len(mf2s) > 0 && e.h.Canonical { mf2w := make([]encStructFieldObj, newlen+len(mf2s)) for j = 0; j < newlen; j++ { kv = fkvs[j] mf2w[j] = encStructFieldObj{kv.v.encName, kv.r, nil, kv.v.path.encNameAsciiAlphaNum, true} } for _, v := range mf2s { mf2w[j] = encStructFieldObj{v.v, reflect.Value{}, v.i, false, false} j++ } sort.Sort((encStructFieldObjSlice)(mf2w)) for _, v := range mf2w { e.mapElemKey() e.kStructFieldKey(ti.keyType, v.ascii, v.key) e.mapElemValue() if v.isRv { e.encodeValue(v.rv, nil) } else { e.encode(v.intf) } } } else { keytyp := ti.keyType for j = 0; j < newlen; j++ { kv = fkvs[j] e.mapElemKey() e.kStructFieldKey(keytyp, kv.v.path.encNameAsciiAlphaNum, kv.v.encName) e.mapElemValue() e.encodeValue(kv.r, nil) } for _, v := range mf2s { e.mapElemKey() e.kStructFieldKey(keytyp, false, v.v) e.mapElemValue() e.encode(v.i) } } e.mapEnd() } else { newlen = len(tisfi) for i, si := range tisfi { // use unsorted array (to match sequence in struct) kv.r = si.path.field(rv) // use the zero value. // if a reference or struct, set to nil (so you do not output too much) if si.path.omitEmpty && isEmptyValue(kv.r, e.h.TypeInfos, 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[i] = kv } // encode it all e.arrayStart(newlen) for j = 0; j < newlen; j++ { e.arrayElem() e.encodeValue(fkvs[j].r, nil) } e.arrayEnd() } // 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. e.slist.put(fkvs) } func (e *Encoder) kMap(f *codecFnInfo, rv reflect.Value) { l := rvLenMap(rv) e.mapStart(l) if l == 0 { e.mapEnd() return } // 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 ktypeKind := reflect.Kind(f.ti.keykind) vtypeKind := reflect.Kind(f.ti.elemkind) rtval := f.ti.elem rtvalkind := vtypeKind for rtvalkind == reflect.Ptr { rtval = rtval.Elem() rtvalkind = rtval.Kind() } if rtvalkind != reflect.Interface { valFn = e.h.fn(rtval) } var rvv = mapAddrLoopvarRV(f.ti.elem, vtypeKind) rtkey := f.ti.key var keyTypeIsString = stringTypId == rt2id(rtkey) // rtkeyid if keyTypeIsString { keyFn = e.h.fn(rtkey) } else { for rtkey.Kind() == reflect.Ptr { rtkey = rtkey.Elem() } if rtkey.Kind() != reflect.Interface { keyFn = e.h.fn(rtkey) } } if e.h.Canonical { e.kMapCanonical(f.ti, rv, rvv, keyFn, valFn) e.mapEnd() return } var rvk = mapAddrLoopvarRV(f.ti.key, ktypeKind) var it mapIter mapRange(&it, rv, rvk, rvv, true) for it.Next() { e.mapElemKey() if keyTypeIsString { e.e.EncodeString(it.Key().String()) } else { e.encodeValue(it.Key(), keyFn) } e.mapElemValue() e.encodeValue(it.Value(), valFn) } it.Done() e.mapEnd() } func (e *Encoder) kMapCanonical(ti *typeInfo, rv, rvv reflect.Value, keyFn, valFn *codecFn) { // The base kind of the type of the map key is sufficient for ordering. // We only do out of band if that kind is not ordered (number or string), bool or time.Time. // If the key is a predeclared type, directly call methods on encDriver e.g. EncodeString // but if not, call encodeValue, in case it has an extension registered or otherwise. rtkey := ti.key rtkeydecl := rtkey.PkgPath() == "" && rtkey.Name() != "" // key type is predeclared mks := rv.MapKeys() rtkeyKind := rtkey.Kind() kfast := mapKeyFastKindFor(rtkeyKind) visindirect := mapStoresElemIndirect(uintptr(ti.elemsize)) visref := refBitset.isset(ti.elemkind) switch rtkeyKind { case reflect.Bool: // though bool keys make no sense in a map, it *could* happen. // in that case, we MUST support it in reflection mode, // as that is the fallback for even codecgen and others. // sort the keys so that false comes before true // ie if 2 keys in order (true, false), then swap them if len(mks) == 2 && mks[0].Bool() { mks[0], mks[1] = mks[1], mks[0] } for i := range mks { e.mapElemKey() if rtkeydecl { e.e.EncodeBool(mks[i].Bool()) } else { e.encodeValueNonNil(mks[i], keyFn) } e.mapElemValue() e.encodeValue(mapGet(rv, mks[i], rvv, kfast, visindirect, visref), valFn) } 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 { e.mapElemKey() if rtkeydecl { e.e.EncodeString(mksv[i].v) } else { e.encodeValueNonNil(mksv[i].r, keyFn) } e.mapElemValue() e.encodeValue(mapGet(rv, mksv[i].r, rvv, kfast, visindirect, visref), valFn) } case reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uint, reflect.Uintptr: mksv := make([]uint64Rv, len(mks)) for i, k := range mks { v := &mksv[i] v.r = k v.v = k.Uint() } sort.Sort(uint64RvSlice(mksv)) for i := range mksv { e.mapElemKey() if rtkeydecl { e.e.EncodeUint(mksv[i].v) } else { e.encodeValueNonNil(mksv[i].r, keyFn) } e.mapElemValue() e.encodeValue(mapGet(rv, mksv[i].r, rvv, kfast, visindirect, visref), valFn) } case reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, reflect.Int: mksv := make([]int64Rv, len(mks)) for i, k := range mks { v := &mksv[i] v.r = k v.v = k.Int() } sort.Sort(int64RvSlice(mksv)) for i := range mksv { e.mapElemKey() if rtkeydecl { e.e.EncodeInt(mksv[i].v) } else { e.encodeValueNonNil(mksv[i].r, keyFn) } e.mapElemValue() e.encodeValue(mapGet(rv, mksv[i].r, rvv, kfast, visindirect, visref), valFn) } case reflect.Float32: mksv := make([]float64Rv, len(mks)) for i, k := range mks { v := &mksv[i] v.r = k v.v = k.Float() } sort.Sort(float64RvSlice(mksv)) for i := range mksv { e.mapElemKey() if rtkeydecl { e.e.EncodeFloat32(float32(mksv[i].v)) } else { e.encodeValueNonNil(mksv[i].r, keyFn) } e.mapElemValue() e.encodeValue(mapGet(rv, mksv[i].r, rvv, kfast, visindirect, visref), valFn) } case reflect.Float64: mksv := make([]float64Rv, len(mks)) for i, k := range mks { v := &mksv[i] v.r = k v.v = k.Float() } sort.Sort(float64RvSlice(mksv)) for i := range mksv { e.mapElemKey() if rtkeydecl { e.e.EncodeFloat64(mksv[i].v) } else { e.encodeValueNonNil(mksv[i].r, keyFn) } e.mapElemValue() e.encodeValue(mapGet(rv, mksv[i].r, rvv, kfast, visindirect, visref), valFn) } default: if rtkey == 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 { e.mapElemKey() e.e.EncodeTime(mksv[i].v) e.mapElemValue() e.encodeValue(mapGet(rv, mksv[i].r, rvv, kfast, visindirect, visref), valFn) } break } // out-of-band // first encode each key to a []byte first, then sort them, then record bs0 := e.blist.get(len(mks) * 16) mksv := bs0 mksbv := make([]bytesRv, len(mks)) func() { // replicate sideEncode logic defer func(wb bytesEncAppender, bytes bool, c containerState, state interface{}) { e.wb = wb e.bytes = bytes e.c = c e.e.restoreState(state) }(e.wb, e.bytes, e.c, e.e.captureState()) // e2 := NewEncoderBytes(&mksv, e.hh) e.wb = bytesEncAppender{mksv[:0], &mksv} e.bytes = true e.c = 0 e.e.resetState() for i, k := range mks { v := &mksbv[i] l := len(mksv) e.c = containerMapKey e.encodeValue(k, nil) e.atEndOfEncode() e.w().end() v.r = k v.v = mksv[l:] } }() sort.Sort(bytesRvSlice(mksbv)) for j := range mksbv { e.mapElemKey() e.encWr.writeb(mksbv[j].v) e.mapElemValue() e.encodeValue(mapGet(rv, mksbv[j].r, rvv, kfast, visindirect, visref), valFn) } e.blist.put(mksv) if !byteSliceSameData(bs0, mksv) { e.blist.put(bs0) } } } // Encoder writes an object to an output stream in a supported format. // // Encoder is NOT safe for concurrent use i.e. a Encoder cannot be used // concurrently in multiple goroutines. // // However, as Encoder could be allocation heavy to initialize, a Reset method is provided // so its state can be reused to decode new input streams repeatedly. // This is the idiomatic way to use. type Encoder struct { panicHdl e encDriver h *BasicHandle // hopefully, reduce derefencing cost by laying the encWriter inside the Encoder encWr // ---- cpu cache line boundary hh Handle blist bytesFreelist err error // ---- cpu cache line boundary // ---- writable fields during execution --- *try* to keep in sep cache line // ci holds interfaces during an encoding (if CheckCircularRef=true) // // We considered using a []uintptr (slice of pointer addresses) retrievable via rv.UnsafeAddr. // However, it is possible for the same pointer to point to 2 different types e.g. // type T struct { tHelper } // Here, for var v T; &v and &v.tHelper are the same pointer. // Consequently, we need a tuple of type and pointer, which interface{} natively provides. ci []interface{} // []uintptr perType encPerType slist sfiRvFreelist } // NewEncoder returns an Encoder for encoding into an io.Writer. // // For efficiency, Users are encouraged to configure WriterBufferSize on the handle // OR pass in a memory buffered writer (eg bufio.Writer, bytes.Buffer). func NewEncoder(w io.Writer, h Handle) *Encoder { e := h.newEncDriver().encoder() if w != nil { 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 := h.newEncDriver().encoder() if out != nil { e.ResetBytes(out) } return e } func (e *Encoder) HandleName() string { return e.hh.Name() } func (e *Encoder) init(h Handle) { initHandle(h) e.err = errEncoderNotInitialized e.bytes = true e.hh = h e.h = h.getBasicHandle() e.be = e.hh.isBinary() } func (e *Encoder) w() *encWr { return &e.encWr } func (e *Encoder) resetCommon() { e.e.reset() if e.ci != nil { e.ci = e.ci[:0] } e.c = 0 e.calls = 0 e.seq = 0 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) { e.bytes = false if e.wf == nil { e.wf = new(bufioEncWriter) } e.wf.reset(w, e.h.WriterBufferSize, &e.blist) e.resetCommon() } // ResetBytes resets the Encoder with a new destination output []byte. func (e *Encoder) ResetBytes(out *[]byte) { e.bytes = true e.wb.reset(encInBytes(out), out) 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) { // tried to use closure, as runtime optimizes defer with no params. // This seemed to be causing weird issues (like circular reference found, unexpected panic, etc). // Also, see https://github.com/golang/go/issues/14939#issuecomment-417836139 if !debugging { defer func() { // if error occurred during encoding, return that error; // else if error occurred on end'ing (i.e. during flush), return that error. if x := recover(); x != nil { panicValToErr(e, x, &e.err) err = e.err } }() } e.MustEncode(v) return } // MustEncode is like Encode, but panics if unable to Encode. // // Note: This provides insight to the code location that triggered the error. func (e *Encoder) MustEncode(v interface{}) { halt.onerror(e.err) if e.hh == nil { halt.onerror(errNoFormatHandle) } e.calls++ e.encode(v) e.calls-- if e.calls == 0 { e.atEndOfEncode() e.w().end() } } // Release is a no-op. // // Deprecated: Pooled resources are not used with an Encoder. // This method is kept for compatibility reasons only. func (e *Encoder) Release() { } func (e *Encoder) encode(iv interface{}) { // MARKER: a switch with only concrete types can be optimized. // consequently, we deal with nil and interfaces outside the switch. if iv == nil { e.e.EncodeNil() return } rv, ok := isNil(iv) if ok { e.e.EncodeNil() return } switch v := iv.(type) { // case nil: // case Selfer: case Raw: e.rawBytes(v) case reflect.Value: e.encodeValue(v, nil) case string: e.e.EncodeString(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 complex64: e.encodeComplex64(v) case complex128: e.encodeComplex128(v) case time.Time: e.e.EncodeTime(v) case []byte: e.e.EncodeStringBytesRaw(v) case *Raw: e.rawBytes(*v) case *string: e.e.EncodeString(*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 *complex64: e.encodeComplex64(*v) case *complex128: e.encodeComplex128(*v) case *time.Time: e.e.EncodeTime(*v) case *[]byte: if *v == nil { e.e.EncodeNil() } else { e.e.EncodeStringBytesRaw(*v) } default: // we can't check non-predefined types, as they might be a Selfer or extension. if skipFastpathTypeSwitchInDirectCall || !fastpathEncodeTypeSwitch(iv, e) { e.encodeValue(rv, nil) } } } // encodeValue will encode a value. // // Note that encodeValue will handle nil in the stream early, so that the // subsequent calls i.e. kXXX methods, etc do not have to handle it themselves. func (e *Encoder) encodeValue(rv reflect.Value, fn *codecFn) { // if a valid fn is passed, it MUST BE for the dereferenced type of rv // MARKER: We check if value is nil here, so that the kXXX method do not have to. var sptr interface{} var rvp reflect.Value var rvpValid bool TOP: switch rv.Kind() { case reflect.Ptr: if rvIsNil(rv) { e.e.EncodeNil() return } rvpValid = true rvp = rv rv = rv.Elem() goto TOP case reflect.Interface: if rvIsNil(rv) { e.e.EncodeNil() return } rvpValid = false rvp = reflect.Value{} rv = rv.Elem() goto TOP case reflect.Struct: if rvpValid && e.h.CheckCircularRef { sptr = rv2i(rvp) for _, vv := range e.ci { if eq4i(sptr, vv) { // error if sptr already seen e.errorf("circular reference found: %p, %T", sptr, sptr) } } e.ci = append(e.ci, sptr) } case reflect.Slice, reflect.Map, reflect.Chan: if rvIsNil(rv) { e.e.EncodeNil() return } case reflect.Invalid, reflect.Func: e.e.EncodeNil() return } if fn == nil { fn = e.h.fn(rv.Type()) } if !fn.i.addrE { // typically, addrE = false, so check it first // keep rv same } else if rvpValid { rv = rvp } else { rv = e.addrRV(rv, fn.i.ti.rt, fn.i.ti.ptr) } fn.fe(e, &fn.i, rv) if sptr != nil { // remove sptr e.ci = e.ci[:len(e.ci)-1] } } // encodeValueNonNil can encode a number, bool, or string // OR non-nil values of kind map, slice and chan. func (e *Encoder) encodeValueNonNil(rv reflect.Value, fn *codecFn) { if fn == nil { fn = e.h.fn(rv.Type()) } if fn.i.addrE { // typically, addrE = false, so check it first rv = e.addrRV(rv, fn.i.ti.rt, fn.i.ti.ptr) } fn.fe(e, &fn.i, rv) } // addrRV returns a addressable value which may be readonly func (e *Encoder) addrRV(rv reflect.Value, typ, ptrType reflect.Type) (rva reflect.Value) { if rv.CanAddr() { return rvAddr(rv, ptrType) } if e.h.NoAddressableReadonly { rva = reflect.New(typ) rvSetDirect(rva.Elem(), rv) return } return rvAddr(e.perType.AddressableRO(rv), ptrType) } func (e *Encoder) marshalUtf8(bs []byte, fnerr error) { e.onerror(fnerr) if bs == nil { e.e.EncodeNil() } else { e.e.EncodeString(stringView(bs)) } } func (e *Encoder) marshalAsis(bs []byte, fnerr error) { e.onerror(fnerr) if bs == nil { e.e.EncodeNil() } else { e.encWr.writeb(bs) // e.asis(bs) } } func (e *Encoder) marshalRaw(bs []byte, fnerr error) { e.onerror(fnerr) if bs == nil { e.e.EncodeNil() } else { e.e.EncodeStringBytesRaw(bs) } } func (e *Encoder) rawBytes(vv Raw) { v := []byte(vv) if !e.h.Raw { e.errorf("Raw values cannot be encoded: %v", v) } e.encWr.writeb(v) } func (e *Encoder) wrapErr(v error, err *error) { *err = wrapCodecErr(v, e.hh.Name(), 0, true) } // ---- container tracker methods // Note: We update the .c after calling the callback. // This way, the callback can know what the last status was. func (e *Encoder) mapStart(length int) { e.e.WriteMapStart(length) e.c = containerMapStart } func (e *Encoder) mapElemKey() { if e.js { e.jsondriver().WriteMapElemKey() } e.c = containerMapKey } func (e *Encoder) mapElemValue() { if e.js { e.jsondriver().WriteMapElemValue() } e.c = containerMapValue } func (e *Encoder) mapEnd() { e.e.WriteMapEnd() e.c = 0 } func (e *Encoder) arrayStart(length int) { e.e.WriteArrayStart(length) e.c = containerArrayStart } func (e *Encoder) arrayElem() { if e.js { e.jsondriver().WriteArrayElem() } e.c = containerArrayElem } func (e *Encoder) arrayEnd() { e.e.WriteArrayEnd() e.c = 0 } // ---------- func (e *Encoder) haltOnMbsOddLen(length int) { if length&1 != 0 { // similar to &1==1 or %2 == 1 e.errorf("mapBySlice requires even slice length, but got %v", length) } } func (e *Encoder) atEndOfEncode() { // e.e.atEndOfEncode() if e.js { e.jsondriver().atEndOfEncode() } } func (e *Encoder) sideEncode(v interface{}, basetype reflect.Type, bs *[]byte) { // rv := baseRV(v) // e2 := NewEncoderBytes(bs, e.hh) // e2.encodeValue(rv, e2.h.fnNoExt(basetype)) // e2.atEndOfEncode() // e2.w().end() defer func(wb bytesEncAppender, bytes bool, c containerState, state interface{}) { e.wb = wb e.bytes = bytes e.c = c e.e.restoreState(state) }(e.wb, e.bytes, e.c, e.e.captureState()) e.wb = bytesEncAppender{encInBytes(bs)[:0], bs} e.bytes = true e.c = 0 e.e.resetState() // must call using fnNoExt rv := baseRV(v) e.encodeValue(rv, e.h.fnNoExt(basetype)) e.atEndOfEncode() e.w().end() } func encInBytes(out *[]byte) (in []byte) { in = *out if in == nil { in = make([]byte, defEncByteBufSize) } return } func encStructFieldKey(encName string, ee encDriver, w *encWr, keyType valueType, encNameAsciiAlphaNum bool, js bool) { // use if-else-if, not switch (which compiles to binary-search) // since keyType is typically valueTypeString, branch prediction is pretty good. if keyType == valueTypeString { if js && encNameAsciiAlphaNum { // keyType == valueTypeString w.writeqstr(encName) } else { // keyType == valueTypeString ee.EncodeString(encName) } } else if keyType == valueTypeInt { ee.EncodeInt(must.Int(strconv.ParseInt(encName, 10, 64))) } else if keyType == valueTypeUint { ee.EncodeUint(must.Uint(strconv.ParseUint(encName, 10, 64))) } else if keyType == valueTypeFloat { ee.EncodeFloat64(must.Float(strconv.ParseFloat(encName, 64))) } else { halt.errorf("invalid struct key type: %v", keyType) } }