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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
// Contains code shared by both encode and decode.
// Some shared ideas around encoding/decoding
// ------------------------------------------
//
// If an interface{} is passed, we first do a type assertion to see if it is
// a primitive type or a map/slice of primitive types, and use a fastpath to handle it.
//
// If we start with a reflect.Value, we are already in reflect.Value land and
// will try to grab the function for the underlying Type and directly call that function.
// This is more performant than calling reflect.Value.Interface().
//
// This still helps us bypass many layers of reflection, and give best performance.
//
// Containers
// ------------
// Containers in the stream are either associative arrays (key-value pairs) or
// regular arrays (indexed by incrementing integers).
//
// Some streams support indefinite-length containers, and use a breaking
// byte-sequence to denote that the container has come to an end.
//
// Some streams also are text-based, and use explicit separators to denote the
// end/beginning of different values.
//
// Philosophy
// ------------
// On decode, this codec will update containers appropriately:
// - If struct, update fields from stream into fields of struct.
// If field in stream not found in struct, handle appropriately (based on option).
// If a struct field has no corresponding value in the stream, leave it AS IS.
// If nil in stream, set value to nil/zero value.
// - If map, update map from stream.
// If the stream value is NIL, set the map to nil.
// - if slice, try to update up to length of array in stream.
// if container len is less than stream array length,
// and container cannot be expanded, handled (based on option).
// This means you can decode 4-element stream array into 1-element array.
//
// ------------------------------------
// On encode, user can specify omitEmpty. This means that the value will be omitted
// if the zero value. The problem may occur during decode, where omitted values do not affect
// the value being decoded into. This means that if decoding into a struct with an
// int field with current value=5, and the field is omitted in the stream, then after
// decoding, the value will still be 5 (not 0).
// omitEmpty only works if you guarantee that you always decode into zero-values.
//
// ------------------------------------
// We could have truncated a map to remove keys not available in the stream,
// or set values in the struct which are not in the stream to their zero values.
// We decided against it because there is no efficient way to do it.
// We may introduce it as an option later.
// However, that will require enabling it for both runtime and code generation modes.
//
// To support truncate, we need to do 2 passes over the container:
// map
// - first collect all keys (e.g. in k1)
// - for each key in stream, mark k1 that the key should not be removed
// - after updating map, do second pass and call delete for all keys in k1 which are not marked
// struct:
// - for each field, track the *typeInfo s1
// - iterate through all s1, and for each one not marked, set value to zero
// - this involves checking the possible anonymous fields which are nil ptrs.
// too much work.
//
// ------------------------------------------
// Error Handling is done within the library using panic.
//
// This way, the code doesn't have to keep checking if an error has happened,
// and we don't have to keep sending the error value along with each call
// or storing it in the En|Decoder and checking it constantly along the way.
//
// We considered storing the error is En|Decoder.
// - once it has its err field set, it cannot be used again.
// - panicing will be optional, controlled by const flag.
// - code should always check error first and return early.
//
// We eventually decided against it as it makes the code clumsier to always
// check for these error conditions.
//
// ------------------------------------------
// We use sync.Pool only for the aid of long-lived objects shared across multiple goroutines.
// Encoder, Decoder, enc|decDriver, reader|writer, etc do not fall into this bucket.
//
// Also, GC is much better now, eliminating some of the reasons to use a shared pool structure.
// Instead, the short-lived objects use free-lists that live as long as the object exists.
//
// ------------------------------------------
// Performance is affected by the following:
// - Bounds Checking
// - Inlining
// - Pointer chasing
// This package tries hard to manage the performance impact of these.
//
// ------------------------------------------
// To alleviate performance due to pointer-chasing:
// - Prefer non-pointer values in a struct field
// - Refer to these directly within helper classes
// e.g. json.go refers directly to d.d.decRd
//
// We made the changes to embed En/Decoder in en/decDriver,
// but we had to explicitly reference the fields as opposed to using a function
// to get the better performance that we were looking for.
// For example, we explicitly call d.d.decRd.fn() instead of d.d.r().fn().
//
// ------------------------------------------
// Bounds Checking
// - Allow bytesDecReader to incur "bounds check error", and
// recover that as an io.EOF.
// This allows the bounds check branch to always be taken by the branch predictor,
// giving better performance (in theory), while ensuring that the code is shorter.
//
// ------------------------------------------
// Escape Analysis
// - Prefer to return non-pointers if the value is used right away.
// Newly allocated values returned as pointers will be heap-allocated as they escape.
//
// Prefer functions and methods that
// - take no parameters and
// - return no results and
// - do not allocate.
// These are optimized by the runtime.
// For example, in json, we have dedicated functions for ReadMapElemKey, etc
// which do not delegate to readDelim, as readDelim takes a parameter.
// The difference in runtime was as much as 5%.
import (
"bytes"
"encoding"
"encoding/binary"
"errors"
"fmt"
"io"
"math"
"reflect"
"sort"
"strconv"
"strings"
"sync"
"sync/atomic"
"time"
"unicode/utf8"
)
const (
// rvNLen is the length of the array for readn or writen calls
rwNLen = 7
// scratchByteArrayLen = 64
// initCollectionCap = 16 // 32 is defensive. 16 is preferred.
// Support encoding.(Binary|Text)(Unm|M)arshaler.
// This constant flag will enable or disable it.
supportMarshalInterfaces = true
// for debugging, set this to false, to catch panic traces.
// Note that this will always cause rpc tests to fail, since they need io.EOF sent via panic.
recoverPanicToErr = true
// arrayCacheLen is the length of the cache used in encoder or decoder for
// allowing zero-alloc initialization.
// arrayCacheLen = 8
// size of the cacheline: defaulting to value for archs: amd64, arm64, 386
// should use "runtime/internal/sys".CacheLineSize, but that is not exposed.
cacheLineSize = 64
wordSizeBits = 32 << (^uint(0) >> 63) // strconv.IntSize
wordSize = wordSizeBits / 8
// so structFieldInfo fits into 8 bytes
maxLevelsEmbedding = 14
// xdebug controls whether xdebugf prints any output
xdebug = true
)
var (
oneByteArr [1]byte
zeroByteSlice = oneByteArr[:0:0]
codecgen bool
halt panicHdl
refBitset bitset32
isnilBitset bitset32
scalarBitset bitset32
digitCharBitset bitset256
numCharBitset bitset256
whitespaceCharBitset bitset256
numCharWithExpBitset64 bitset64
numCharNoExpBitset64 bitset64
whitespaceCharBitset64 bitset64
)
var (
errMapTypeNotMapKind = errors.New("MapType MUST be of Map Kind")
errSliceTypeNotSliceKind = errors.New("SliceType MUST be of Slice Kind")
)
var pool4tiload = sync.Pool{New: func() interface{} { return new(typeInfoLoadArray) }}
func init() {
refBitset = refBitset.
set(byte(reflect.Map)).
set(byte(reflect.Ptr)).
set(byte(reflect.Func)).
set(byte(reflect.Chan)).
set(byte(reflect.UnsafePointer))
isnilBitset = isnilBitset.
set(byte(reflect.Map)).
set(byte(reflect.Ptr)).
set(byte(reflect.Func)).
set(byte(reflect.Chan)).
set(byte(reflect.UnsafePointer)).
set(byte(reflect.Interface)).
set(byte(reflect.Slice))
scalarBitset = scalarBitset.
set(byte(reflect.Bool)).
set(byte(reflect.Int)).
set(byte(reflect.Int8)).
set(byte(reflect.Int16)).
set(byte(reflect.Int32)).
set(byte(reflect.Int64)).
set(byte(reflect.Uint)).
set(byte(reflect.Uint8)).
set(byte(reflect.Uint16)).
set(byte(reflect.Uint32)).
set(byte(reflect.Uint64)).
set(byte(reflect.Uintptr)).
set(byte(reflect.Float32)).
set(byte(reflect.Float64)).
set(byte(reflect.Complex64)).
set(byte(reflect.Complex128)).
set(byte(reflect.String))
var i byte
for i = 0; i <= utf8.RuneSelf; i++ {
switch i {
case ' ', '\t', '\r', '\n':
whitespaceCharBitset.set(i)
whitespaceCharBitset64 = whitespaceCharBitset64.set(i)
case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
digitCharBitset.set(i)
numCharBitset.set(i)
numCharWithExpBitset64 = numCharWithExpBitset64.set(i - 42)
numCharNoExpBitset64 = numCharNoExpBitset64.set(i)
case '.', '+', '-':
numCharBitset.set(i)
numCharWithExpBitset64 = numCharWithExpBitset64.set(i - 42)
numCharNoExpBitset64 = numCharNoExpBitset64.set(i)
case 'e', 'E':
numCharBitset.set(i)
numCharWithExpBitset64 = numCharWithExpBitset64.set(i - 42)
}
}
}
type handleFlag uint8
const (
initedHandleFlag handleFlag = 1 << iota
binaryHandleFlag
jsonHandleFlag
)
type clsErr struct {
closed bool // is it closed?
errClosed error // error on closing
}
type charEncoding uint8
const (
_ charEncoding = iota // make 0 unset
cUTF8
cUTF16LE
cUTF16BE
cUTF32LE
cUTF32BE
// Deprecated: not a true char encoding value
cRAW charEncoding = 255
)
// valueType is the stream type
type valueType uint8
const (
valueTypeUnset valueType = iota
valueTypeNil
valueTypeInt
valueTypeUint
valueTypeFloat
valueTypeBool
valueTypeString
valueTypeSymbol
valueTypeBytes
valueTypeMap
valueTypeArray
valueTypeTime
valueTypeExt
// valueTypeInvalid = 0xff
)
var valueTypeStrings = [...]string{
"Unset",
"Nil",
"Int",
"Uint",
"Float",
"Bool",
"String",
"Symbol",
"Bytes",
"Map",
"Array",
"Timestamp",
"Ext",
}
func (x valueType) String() string {
if int(x) < len(valueTypeStrings) {
return valueTypeStrings[x]
}
return strconv.FormatInt(int64(x), 10)
}
type seqType uint8
const (
_ seqType = iota
seqTypeArray
seqTypeSlice
seqTypeChan
)
// note that containerMapStart and containerArraySend are not sent.
// This is because the ReadXXXStart and EncodeXXXStart already does these.
type containerState uint8
const (
_ containerState = iota
containerMapStart
containerMapKey
containerMapValue
containerMapEnd
containerArrayStart
containerArrayElem
containerArrayEnd
)
// do not recurse if a containing type refers to an embedded type
// which refers back to its containing type (via a pointer).
// The second time this back-reference happens, break out,
// so as not to cause an infinite loop.
const rgetMaxRecursion = 2
// Anecdotally, we believe most types have <= 12 fields.
// - even Java's PMD rules set TooManyFields threshold to 15.
// However, go has embedded fields, which should be regarded as
// top level, allowing structs to possibly double or triple.
// In addition, we don't want to keep creating transient arrays,
// especially for the sfi index tracking, and the evtypes tracking.
//
// So - try to keep typeInfoLoadArray within 2K bytes
const (
typeInfoLoadArraySfisLen = 16
typeInfoLoadArraySfiidxLen = 8 * 112
typeInfoLoadArrayEtypesLen = 12
typeInfoLoadArrayBLen = 8 * 4
)
// fauxUnion is used to keep track of the primitives decoded.
//
// Without it, we would have to decode each primitive and wrap it
// in an interface{}, causing an allocation.
// In this model, the primitives are decoded in a "pseudo-atomic" fashion,
// so we can rest assured that no other decoding happens while these
// primitives are being decoded.
//
// maps and arrays are not handled by this mechanism.
type fauxUnion struct {
// r RawExt // used for RawExt, uint, []byte.
// primitives below
u uint64
i int64
f float64
l []byte
s string
// ---- cpu cache line boundary?
t time.Time
b bool
// state
v valueType
}
// typeInfoLoad is a transient object used while loading up a typeInfo.
type typeInfoLoad struct {
etypes []uintptr
sfis []structFieldInfo
}
// typeInfoLoadArray is a cache object used to efficiently load up a typeInfo without
// much allocation.
type typeInfoLoadArray struct {
sfis [typeInfoLoadArraySfisLen]structFieldInfo
sfiidx [typeInfoLoadArraySfiidxLen]byte
etypes [typeInfoLoadArrayEtypesLen]uintptr
b [typeInfoLoadArrayBLen]byte // scratch - used for struct field names
}
// mirror json.Marshaler and json.Unmarshaler here,
// so we don't import the encoding/json package
type jsonMarshaler interface {
MarshalJSON() ([]byte, error)
}
type jsonUnmarshaler interface {
UnmarshalJSON([]byte) error
}
type isZeroer interface {
IsZero() bool
}
type codecError struct {
name string
err interface{}
}
func (e codecError) Cause() error {
switch xerr := e.err.(type) {
case nil:
return nil
case error:
return xerr
case string:
return errors.New(xerr)
case fmt.Stringer:
return errors.New(xerr.String())
default:
return fmt.Errorf("%v", e.err)
}
}
func (e codecError) Error() string {
return fmt.Sprintf("%s error: %v", e.name, e.err)
}
var (
bigen = binary.BigEndian
structInfoFieldName = "_struct"
mapStrIntfTyp = reflect.TypeOf(map[string]interface{}(nil))
mapIntfIntfTyp = reflect.TypeOf(map[interface{}]interface{}(nil))
intfSliceTyp = reflect.TypeOf([]interface{}(nil))
intfTyp = intfSliceTyp.Elem()
reflectValTyp = reflect.TypeOf((*reflect.Value)(nil)).Elem()
stringTyp = reflect.TypeOf("")
timeTyp = reflect.TypeOf(time.Time{})
rawExtTyp = reflect.TypeOf(RawExt{})
rawTyp = reflect.TypeOf(Raw{})
uintptrTyp = reflect.TypeOf(uintptr(0))
uint8Typ = reflect.TypeOf(uint8(0))
uint8SliceTyp = reflect.TypeOf([]uint8(nil))
uintTyp = reflect.TypeOf(uint(0))
intTyp = reflect.TypeOf(int(0))
mapBySliceTyp = reflect.TypeOf((*MapBySlice)(nil)).Elem()
binaryMarshalerTyp = reflect.TypeOf((*encoding.BinaryMarshaler)(nil)).Elem()
binaryUnmarshalerTyp = reflect.TypeOf((*encoding.BinaryUnmarshaler)(nil)).Elem()
textMarshalerTyp = reflect.TypeOf((*encoding.TextMarshaler)(nil)).Elem()
textUnmarshalerTyp = reflect.TypeOf((*encoding.TextUnmarshaler)(nil)).Elem()
jsonMarshalerTyp = reflect.TypeOf((*jsonMarshaler)(nil)).Elem()
jsonUnmarshalerTyp = reflect.TypeOf((*jsonUnmarshaler)(nil)).Elem()
selferTyp = reflect.TypeOf((*Selfer)(nil)).Elem()
missingFielderTyp = reflect.TypeOf((*MissingFielder)(nil)).Elem()
iszeroTyp = reflect.TypeOf((*isZeroer)(nil)).Elem()
uint8TypId = rt2id(uint8Typ)
uint8SliceTypId = rt2id(uint8SliceTyp)
rawExtTypId = rt2id(rawExtTyp)
rawTypId = rt2id(rawTyp)
intfTypId = rt2id(intfTyp)
timeTypId = rt2id(timeTyp)
stringTypId = rt2id(stringTyp)
mapStrIntfTypId = rt2id(mapStrIntfTyp)
mapIntfIntfTypId = rt2id(mapIntfIntfTyp)
intfSliceTypId = rt2id(intfSliceTyp)
// mapBySliceTypId = rt2id(mapBySliceTyp)
intBitsize = uint8(intTyp.Bits())
uintBitsize = uint8(uintTyp.Bits())
// bsAll0x00 = []byte{0, 0, 0, 0, 0, 0, 0, 0}
bsAll0xff = []byte{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}
chkOvf checkOverflow
errNoFieldNameToStructFieldInfo = errors.New("no field name passed to parseStructFieldInfo")
)
var defTypeInfos = NewTypeInfos([]string{"codec", "json"})
var immutableKindsSet = [32]bool{
// reflect.Invalid: ,
reflect.Bool: true,
reflect.Int: true,
reflect.Int8: true,
reflect.Int16: true,
reflect.Int32: true,
reflect.Int64: true,
reflect.Uint: true,
reflect.Uint8: true,
reflect.Uint16: true,
reflect.Uint32: true,
reflect.Uint64: true,
reflect.Uintptr: true,
reflect.Float32: true,
reflect.Float64: true,
reflect.Complex64: true,
reflect.Complex128: true,
// reflect.Array
// reflect.Chan
// reflect.Func: true,
// reflect.Interface
// reflect.Map
// reflect.Ptr
// reflect.Slice
reflect.String: true,
// reflect.Struct
// reflect.UnsafePointer
}
// SelfExt is a sentinel extension signifying that types
// registered with it SHOULD be encoded and decoded
// based on the native mode of the format.
//
// This allows users to define a tag for an extension,
// but signify that the types should be encoded/decoded as the native encoding.
// This way, users need not also define how to encode or decode the extension.
var SelfExt = &extFailWrapper{}
// Selfer defines methods by which a value can encode or decode itself.
//
// Any type which implements Selfer will be able to encode or decode itself.
// Consequently, during (en|de)code, this takes precedence over
// (text|binary)(M|Unm)arshal or extension support.
//
// By definition, it is not allowed for a Selfer to directly call Encode or Decode on itself.
// If that is done, Encode/Decode will rightfully fail with a Stack Overflow style error.
// For example, the snippet below will cause such an error.
// type testSelferRecur struct{}
// func (s *testSelferRecur) CodecEncodeSelf(e *Encoder) { e.MustEncode(s) }
// func (s *testSelferRecur) CodecDecodeSelf(d *Decoder) { d.MustDecode(s) }
//
// Note: *the first set of bytes of any value MUST NOT represent nil in the format*.
// This is because, during each decode, we first check the the next set of bytes
// represent nil, and if so, we just set the value to nil.
type Selfer interface {
CodecEncodeSelf(*Encoder)
CodecDecodeSelf(*Decoder)
}
// MissingFielder defines the interface allowing structs to internally decode or encode
// values which do not map to struct fields.
//
// We expect that this interface is bound to a pointer type (so the mutation function works).
//
// A use-case is if a version of a type unexports a field, but you want compatibility between
// both versions during encoding and decoding.
//
// Note that the interface is completely ignored during codecgen.
type MissingFielder interface {
// CodecMissingField is called to set a missing field and value pair.
//
// It returns true if the missing field was set on the struct.
CodecMissingField(field []byte, value interface{}) bool
// CodecMissingFields returns the set of fields which are not struct fields
CodecMissingFields() map[string]interface{}
}
// MapBySlice is a tag interface that denotes wrapped slice should encode as a map in the stream.
// The slice contains a sequence of key-value pairs.
// This affords storing a map in a specific sequence in the stream.
//
// Example usage:
// type T1 []string // or []int or []Point or any other "slice" type
// func (_ T1) MapBySlice{} // T1 now implements MapBySlice, and will be encoded as a map
// type T2 struct { KeyValues T1 }
//
// var kvs = []string{"one", "1", "two", "2", "three", "3"}
// var v2 = T2{ KeyValues: T1(kvs) }
// // v2 will be encoded like the map: {"KeyValues": {"one": "1", "two": "2", "three": "3"} }
//
// The support of MapBySlice affords the following:
// - A slice type which implements MapBySlice will be encoded as a map
// - A slice can be decoded from a map in the stream
// - It MUST be a slice type (not a pointer receiver) that implements MapBySlice
type MapBySlice interface {
MapBySlice()
}
// BasicHandle encapsulates the common options and extension functions.
//
// Deprecated: DO NOT USE DIRECTLY. EXPORTED FOR GODOC BENEFIT. WILL BE REMOVED.
type BasicHandle struct {
// BasicHandle is always a part of a different type.
// It doesn't have to fit into it own cache lines.
// TypeInfos is used to get the type info for any type.
//
// If not configured, the default TypeInfos is used, which uses struct tag keys: codec, json
TypeInfos *TypeInfos
// Note: BasicHandle is not comparable, due to these slices here (extHandle, intf2impls).
// If *[]T is used instead, this becomes comparable, at the cost of extra indirection.
// Thses slices are used all the time, so keep as slices (not pointers).
extHandle
rtidFns atomicRtidFnSlice
rtidFnsNoExt atomicRtidFnSlice
// ---- cache line
DecodeOptions
// ---- cache line
EncodeOptions
intf2impls
mu sync.Mutex
inited uint32 // holds if inited, and also handle flags (binary encoding, json handler, etc)
RPCOptions
// TimeNotBuiltin configures whether time.Time should be treated as a builtin type.
//
// All Handlers should know how to encode/decode time.Time as part of the core
// format specification, or as a standard extension defined by the format.
//
// However, users can elect to handle time.Time as a custom extension, or via the
// standard library's encoding.Binary(M|Unm)arshaler or Text(M|Unm)arshaler interface.
// To elect this behavior, users can set TimeNotBuiltin=true.
//
// Note: Setting TimeNotBuiltin=true can be used to enable the legacy behavior
// (for Cbor and Msgpack), where time.Time was not a builtin supported type.
//
// Note: DO NOT CHANGE AFTER FIRST USE.
//
// Once a Handle has been used, do not modify this option.
// It will lead to unexpected behaviour during encoding and decoding.
TimeNotBuiltin bool
// ExplicitRelease configures whether Release() is implicitly called after an encode or
// decode call.
//
// If you will hold onto an Encoder or Decoder for re-use, by calling Reset(...)
// on it or calling (Must)Encode repeatedly into a given []byte or io.Writer,
// then you do not want it to be implicitly closed after each Encode/Decode call.
// Doing so will unnecessarily return resources to the shared pool, only for you to
// grab them right after again to do another Encode/Decode call.
//
// Instead, you configure ExplicitRelease=true, and you explicitly call Release() when
// you are truly done.
//
// As an alternative, you can explicitly set a finalizer - so its resources
// are returned to the shared pool before it is garbage-collected. Do it as below:
// runtime.SetFinalizer(e, (*Encoder).Release)
// runtime.SetFinalizer(d, (*Decoder).Release)
//
// Deprecated: This is not longer used as pools are only used for long-lived objects
// which are shared across goroutines.
// Setting this value has no effect. It is maintained for backward compatibility.
ExplicitRelease bool
// ---- cache line
}
// basicHandle returns an initialized BasicHandle from the Handle.
func basicHandle(hh Handle) (x *BasicHandle) {
x = hh.getBasicHandle()
// ** We need to simulate once.Do, to ensure no data race within the block.
// ** Consequently, below would not work.
// if atomic.CompareAndSwapUint32(&x.inited, 0, 1) {
// x.be = hh.isBinary()
// _, x.js = hh.(*JsonHandle)
// x.n = hh.Name()[0]
// }
// simulate once.Do using our own stored flag and mutex as a CompareAndSwap
// is not sufficient, since a race condition can occur within init(Handle) function.
// init is made noinline, so that this function can be inlined by its caller.
if atomic.LoadUint32(&x.inited) == 0 {
x.init(hh)
}
return
}
func (x *BasicHandle) isJs() bool {
return handleFlag(x.inited)&jsonHandleFlag != 0
}
func (x *BasicHandle) isBe() bool {
return handleFlag(x.inited)&binaryHandleFlag != 0
}
//go:noinline
func (x *BasicHandle) init(hh Handle) {
// make it uninlineable, as it is called at most once
x.mu.Lock()
if x.inited == 0 {
var f = initedHandleFlag
if hh.isBinary() {
f |= binaryHandleFlag
}
if _, b := hh.(*JsonHandle); b {
f |= jsonHandleFlag
}
atomic.StoreUint32(&x.inited, uint32(f))
// ensure MapType and SliceType are of correct type
if x.MapType != nil && x.MapType.Kind() != reflect.Map {
panic(errMapTypeNotMapKind)
}
if x.SliceType != nil && x.SliceType.Kind() != reflect.Slice {
panic(errSliceTypeNotSliceKind)
}
}
x.mu.Unlock()
}
func (x *BasicHandle) getBasicHandle() *BasicHandle {
return x
}
func (x *BasicHandle) getTypeInfo(rtid uintptr, rt reflect.Type) (pti *typeInfo) {
if x.TypeInfos == nil {
return defTypeInfos.get(rtid, rt)
}
return x.TypeInfos.get(rtid, rt)
}
func findFn(s []codecRtidFn, rtid uintptr) (i uint, fn *codecFn) {
// binary search. adapted from sort/search.go.
// Note: we use goto (instead of for loop) so this can be inlined.
// h, i, j := 0, 0, len(s)
var h uint // var h, i uint
var j = uint(len(s))
LOOP:
if i < j {
h = i + (j-i)/2
if s[h].rtid < rtid {
i = h + 1
} else {
j = h
}
goto LOOP
}
if i < uint(len(s)) && s[i].rtid == rtid {
fn = s[i].fn
}
return
}
func (x *BasicHandle) fn(rt reflect.Type) (fn *codecFn) {
return x.fnVia(rt, &x.rtidFns, true)
}
func (x *BasicHandle) fnNoExt(rt reflect.Type) (fn *codecFn) {
return x.fnVia(rt, &x.rtidFnsNoExt, false)
}
func (x *BasicHandle) fnVia(rt reflect.Type, fs *atomicRtidFnSlice, checkExt bool) (fn *codecFn) {
rtid := rt2id(rt)
sp := fs.load()
if sp != nil {
if _, fn = findFn(sp, rtid); fn != nil {
return
}
}
fn = x.fnLoad(rt, rtid, checkExt)
x.mu.Lock()
var sp2 []codecRtidFn
sp = fs.load()
if sp == nil {
sp2 = []codecRtidFn{{rtid, fn}}
fs.store(sp2)
} else {
idx, fn2 := findFn(sp, rtid)
if fn2 == nil {
sp2 = make([]codecRtidFn, len(sp)+1)
copy(sp2, sp[:idx])
copy(sp2[idx+1:], sp[idx:])
sp2[idx] = codecRtidFn{rtid, fn}
fs.store(sp2)
}
}
x.mu.Unlock()
return
}
func (x *BasicHandle) fnLoad(rt reflect.Type, rtid uintptr, checkExt bool) (fn *codecFn) {
fn = new(codecFn)
fi := &(fn.i)
ti := x.getTypeInfo(rtid, rt)
fi.ti = ti
rk := reflect.Kind(ti.kind)
// anything can be an extension except the built-in ones: time, raw and rawext
if rtid == timeTypId && !x.TimeNotBuiltin {
fn.fe = (*Encoder).kTime
fn.fd = (*Decoder).kTime
} else if rtid == rawTypId {
fn.fe = (*Encoder).raw
fn.fd = (*Decoder).raw
} else if rtid == rawExtTypId {
fn.fe = (*Encoder).rawExt
fn.fd = (*Decoder).rawExt
fi.addrF = true
fi.addrD = true
fi.addrE = true
} else if xfFn := x.getExt(rtid, checkExt); xfFn != nil {
fi.xfTag, fi.xfFn = xfFn.tag, xfFn.ext
fn.fe = (*Encoder).ext
fn.fd = (*Decoder).ext
fi.addrF = true
fi.addrD = true
if rk == reflect.Struct || rk == reflect.Array {
fi.addrE = true
}
} else if ti.isFlag(tiflagSelfer) || ti.isFlag(tiflagSelferPtr) {
fn.fe = (*Encoder).selferMarshal
fn.fd = (*Decoder).selferUnmarshal
fi.addrF = true
fi.addrD = ti.isFlag(tiflagSelferPtr)
fi.addrE = ti.isFlag(tiflagSelferPtr)
} else if supportMarshalInterfaces && x.isBe() &&
(ti.isFlag(tiflagBinaryMarshaler) || ti.isFlag(tiflagBinaryMarshalerPtr)) &&
(ti.isFlag(tiflagBinaryUnmarshaler) || ti.isFlag(tiflagBinaryUnmarshalerPtr)) {
fn.fe = (*Encoder).binaryMarshal
fn.fd = (*Decoder).binaryUnmarshal
fi.addrF = true
fi.addrD = ti.isFlag(tiflagBinaryUnmarshalerPtr)
fi.addrE = ti.isFlag(tiflagBinaryMarshalerPtr)
} else if supportMarshalInterfaces && !x.isBe() && x.isJs() &&
(ti.isFlag(tiflagJsonMarshaler) || ti.isFlag(tiflagJsonMarshalerPtr)) &&
(ti.isFlag(tiflagJsonUnmarshaler) || ti.isFlag(tiflagJsonUnmarshalerPtr)) {
//If JSON, we should check JSONMarshal before textMarshal
fn.fe = (*Encoder).jsonMarshal
fn.fd = (*Decoder).jsonUnmarshal
fi.addrF = true
fi.addrD = ti.isFlag(tiflagJsonUnmarshalerPtr)
fi.addrE = ti.isFlag(tiflagJsonMarshalerPtr)
} else if supportMarshalInterfaces && !x.isBe() &&
(ti.isFlag(tiflagTextMarshaler) || ti.isFlag(tiflagTextMarshalerPtr)) &&
(ti.isFlag(tiflagTextUnmarshaler) || ti.isFlag(tiflagTextUnmarshalerPtr)) {
fn.fe = (*Encoder).textMarshal
fn.fd = (*Decoder).textUnmarshal
fi.addrF = true
fi.addrD = ti.isFlag(tiflagTextUnmarshalerPtr)
fi.addrE = ti.isFlag(tiflagTextMarshalerPtr)
} else {
if fastpathEnabled && (rk == reflect.Map || rk == reflect.Slice) {
if ti.pkgpath == "" { // un-named slice or map
if idx := fastpathAV.index(rtid); idx != -1 {
fn.fe = fastpathAV[idx].encfn
fn.fd = fastpathAV[idx].decfn
fi.addrD = true
fi.addrF = false
}
} else {
// use mapping for underlying type if there
var rtu reflect.Type
if rk == reflect.Map {
rtu = reflect.MapOf(ti.key, ti.elem)
} else {
rtu = reflect.SliceOf(ti.elem)
}
rtuid := rt2id(rtu)
if idx := fastpathAV.index(rtuid); idx != -1 {
xfnf := fastpathAV[idx].encfn
xrt := fastpathAV[idx].rt
fn.fe = func(e *Encoder, xf *codecFnInfo, xrv reflect.Value) {
xfnf(e, xf, rvConvert(xrv, xrt))
}
fi.addrD = true
fi.addrF = false // meaning it can be an address(ptr) or a value
xfnf2 := fastpathAV[idx].decfn
xptr2rt := reflect.PtrTo(xrt)
fn.fd = func(d *Decoder, xf *codecFnInfo, xrv reflect.Value) {
if xrv.Kind() == reflect.Ptr {
xfnf2(d, xf, rvConvert(xrv, xptr2rt))
} else {
xfnf2(d, xf, rvConvert(xrv, xrt))
}
}
}
}
}
if fn.fe == nil && fn.fd == nil {
switch rk {
case reflect.Bool:
fn.fe = (*Encoder).kBool
fn.fd = (*Decoder).kBool
case reflect.String:
// Do not use different functions based on StringToRaw option,
// as that will statically set the function for a string type,
// and if the Handle is modified thereafter, behaviour is non-deterministic.
// i.e. DO NOT DO:
// if x.StringToRaw {
// fn.fe = (*Encoder).kStringToRaw
// } else {
// fn.fe = (*Encoder).kStringEnc
// }
fn.fe = (*Encoder).kString
fn.fd = (*Decoder).kString
case reflect.Int:
fn.fd = (*Decoder).kInt
fn.fe = (*Encoder).kInt
case reflect.Int8:
fn.fe = (*Encoder).kInt8
fn.fd = (*Decoder).kInt8
case reflect.Int16:
fn.fe = (*Encoder).kInt16
fn.fd = (*Decoder).kInt16
case reflect.Int32:
fn.fe = (*Encoder).kInt32
fn.fd = (*Decoder).kInt32
case reflect.Int64:
fn.fe = (*Encoder).kInt64
fn.fd = (*Decoder).kInt64
case reflect.Uint:
fn.fd = (*Decoder).kUint
fn.fe = (*Encoder).kUint
case reflect.Uint8:
fn.fe = (*Encoder).kUint8
fn.fd = (*Decoder).kUint8
case reflect.Uint16:
fn.fe = (*Encoder).kUint16
fn.fd = (*Decoder).kUint16
case reflect.Uint32:
fn.fe = (*Encoder).kUint32
fn.fd = (*Decoder).kUint32
case reflect.Uint64:
fn.fe = (*Encoder).kUint64
fn.fd = (*Decoder).kUint64
case reflect.Uintptr:
fn.fe = (*Encoder).kUintptr
fn.fd = (*Decoder).kUintptr
case reflect.Float32:
fn.fe = (*Encoder).kFloat32
fn.fd = (*Decoder).kFloat32
case reflect.Float64:
fn.fe = (*Encoder).kFloat64
fn.fd = (*Decoder).kFloat64
case reflect.Invalid:
fn.fe = (*Encoder).kInvalid
fn.fd = (*Decoder).kErr
case reflect.Chan:
fi.seq = seqTypeChan
fn.fe = (*Encoder).kChan
fn.fd = (*Decoder).kSliceForChan
case reflect.Slice:
fi.seq = seqTypeSlice
fn.fe = (*Encoder).kSlice
fn.fd = (*Decoder).kSlice
case reflect.Array:
fi.seq = seqTypeArray
fn.fe = (*Encoder).kArray
fi.addrF = false
fi.addrD = false
rt2 := reflect.SliceOf(ti.elem)
fn.fd = func(d *Decoder, xf *codecFnInfo, xrv reflect.Value) {
// call fnVia directly, so fn(...) is not recursive, and can be inlined
d.h.fnVia(rt2, &x.rtidFns, true).fd(d, xf, rvGetSlice4Array(xrv, rt2))
}
case reflect.Struct:
if ti.anyOmitEmpty ||
ti.isFlag(tiflagMissingFielder) ||
ti.isFlag(tiflagMissingFielderPtr) {
fn.fe = (*Encoder).kStruct
} else {
fn.fe = (*Encoder).kStructNoOmitempty
}
fn.fd = (*Decoder).kStruct
case reflect.Map:
fn.fe = (*Encoder).kMap
fn.fd = (*Decoder).kMap
case reflect.Interface:
// encode: reflect.Interface are handled already by preEncodeValue
fn.fd = (*Decoder).kInterface
fn.fe = (*Encoder).kErr
default:
// reflect.Ptr and reflect.Interface are handled already by preEncodeValue
fn.fe = (*Encoder).kErr
fn.fd = (*Decoder).kErr
}
}
}
return
}
// Handle defines a specific encoding format. It also stores any runtime state
// used during an Encoding or Decoding session e.g. stored state about Types, etc.
//
// Once a handle is configured, it can be shared across multiple Encoders and Decoders.
//
// Note that a Handle is NOT safe for concurrent modification.
//
// A Handle also should not be modified after it is configured and has
// been used at least once. This is because stored state may be out of sync with the
// new configuration, and a data race can occur when multiple goroutines access it.
// i.e. multiple Encoders or Decoders in different goroutines.
//
// Consequently, the typical usage model is that a Handle is pre-configured
// before first time use, and not modified while in use.
// Such a pre-configured Handle is safe for concurrent access.
type Handle interface {
Name() string
// return the basic handle. It may not have been inited.
// Prefer to use basicHandle() helper function that ensures it has been inited.
getBasicHandle() *BasicHandle
newEncDriver() encDriver
newDecDriver() decDriver
isBinary() bool
}
// Raw represents raw formatted bytes.
// We "blindly" store it during encode and retrieve the raw bytes during decode.
// Note: it is dangerous during encode, so we may gate the behaviour
// behind an Encode flag which must be explicitly set.
type Raw []byte
// RawExt represents raw unprocessed extension data.
// Some codecs will decode extension data as a *RawExt
// if there is no registered extension for the tag.
//
// Only one of Data or Value is nil.
// If Data is nil, then the content of the RawExt is in the Value.
type RawExt struct {
Tag uint64
// Data is the []byte which represents the raw ext. If nil, ext is exposed in Value.
// Data is used by codecs (e.g. binc, msgpack, simple) which do custom serialization of types
Data []byte
// Value represents the extension, if Data is nil.
// Value is used by codecs (e.g. cbor, json) which leverage the format to do
// custom serialization of the types.
Value interface{}
}
// BytesExt handles custom (de)serialization of types to/from []byte.
// It is used by codecs (e.g. binc, msgpack, simple) which do custom serialization of the types.
type BytesExt interface {
// WriteExt converts a value to a []byte.
//
// Note: v is a pointer iff the registered extension type is a struct or array kind.
WriteExt(v interface{}) []byte
// ReadExt updates a value from a []byte.
//
// Note: dst is always a pointer kind to the registered extension type.
ReadExt(dst interface{}, src []byte)
}
// InterfaceExt handles custom (de)serialization of types to/from another interface{} value.
// The Encoder or Decoder will then handle the further (de)serialization of that known type.
//
// It is used by codecs (e.g. cbor, json) which use the format to do custom serialization of types.
type InterfaceExt interface {
// ConvertExt converts a value into a simpler interface for easy encoding
// e.g. convert time.Time to int64.
//
// Note: v is a pointer iff the registered extension type is a struct or array kind.
ConvertExt(v interface{}) interface{}
// UpdateExt updates a value from a simpler interface for easy decoding
// e.g. convert int64 to time.Time.
//
// Note: dst is always a pointer kind to the registered extension type.
UpdateExt(dst interface{}, src interface{})
}
// Ext handles custom (de)serialization of custom types / extensions.
type Ext interface {
BytesExt
InterfaceExt
}
// addExtWrapper is a wrapper implementation to support former AddExt exported method.
type addExtWrapper struct {
encFn func(reflect.Value) ([]byte, error)
decFn func(reflect.Value, []byte) error
}
func (x addExtWrapper) WriteExt(v interface{}) []byte {
bs, err := x.encFn(rv4i(v))
if err != nil {
panic(err)
}
return bs
}
func (x addExtWrapper) ReadExt(v interface{}, bs []byte) {
if err := x.decFn(rv4i(v), bs); err != nil {
panic(err)
}
}
func (x addExtWrapper) ConvertExt(v interface{}) interface{} {
return x.WriteExt(v)
}
func (x addExtWrapper) UpdateExt(dest interface{}, v interface{}) {
x.ReadExt(dest, v.([]byte))
}
type bytesExtFailer struct{}
func (bytesExtFailer) WriteExt(v interface{}) []byte {
halt.errorstr("BytesExt.WriteExt is not supported")
return nil
}
func (bytesExtFailer) ReadExt(v interface{}, bs []byte) {
halt.errorstr("BytesExt.ReadExt is not supported")
}
type interfaceExtFailer struct{}
func (interfaceExtFailer) ConvertExt(v interface{}) interface{} {
halt.errorstr("InterfaceExt.ConvertExt is not supported")
return nil
}
func (interfaceExtFailer) UpdateExt(dest interface{}, v interface{}) {
halt.errorstr("InterfaceExt.UpdateExt is not supported")
}
type bytesExtWrapper struct {
interfaceExtFailer
BytesExt
}
type interfaceExtWrapper struct {
bytesExtFailer
InterfaceExt
}
type extFailWrapper struct {
bytesExtFailer
interfaceExtFailer
}
type binaryEncodingType struct{}
func (binaryEncodingType) isBinary() bool { return true }
type textEncodingType struct{}
func (textEncodingType) isBinary() bool { return false }
// noBuiltInTypes is embedded into many types which do not support builtins
// e.g. msgpack, simple, cbor.
type noBuiltInTypes struct{}
func (noBuiltInTypes) EncodeBuiltin(rt uintptr, v interface{}) {}
func (noBuiltInTypes) DecodeBuiltin(rt uintptr, v interface{}) {}
// bigenHelper.
// Users must already slice the x completely, because we will not reslice.
type bigenHelper struct {
x []byte // must be correctly sliced to appropriate len. slicing is a cost.
w *encWr
}
func (z bigenHelper) writeUint16(v uint16) {
bigen.PutUint16(z.x, v)
z.w.writeb(z.x)
}
func (z bigenHelper) writeUint32(v uint32) {
bigen.PutUint32(z.x, v)
z.w.writeb(z.x)
}
func (z bigenHelper) writeUint64(v uint64) {
bigen.PutUint64(z.x, v)
z.w.writeb(z.x)
}
type extTypeTagFn struct {
rtid uintptr
rtidptr uintptr
rt reflect.Type
tag uint64
ext Ext
// _ [1]uint64 // padding
}
type extHandle []extTypeTagFn
// AddExt registes an encode and decode function for a reflect.Type.
// To deregister an Ext, call AddExt with nil encfn and/or nil decfn.
//
// Deprecated: Use SetBytesExt or SetInterfaceExt on the Handle instead.
func (o *extHandle) AddExt(rt reflect.Type, tag byte,
encfn func(reflect.Value) ([]byte, error),
decfn func(reflect.Value, []byte) error) (err error) {
if encfn == nil || decfn == nil {
return o.SetExt(rt, uint64(tag), nil)
}
return o.SetExt(rt, uint64(tag), addExtWrapper{encfn, decfn})
}
// SetExt will set the extension for a tag and reflect.Type.
// Note that the type must be a named type, and specifically not a pointer or Interface.
// An error is returned if that is not honored.
// To Deregister an ext, call SetExt with nil Ext.
//
// Deprecated: Use SetBytesExt or SetInterfaceExt on the Handle instead.
func (o *extHandle) SetExt(rt reflect.Type, tag uint64, ext Ext) (err error) {
// o is a pointer, because we may need to initialize it
// We EXPECT *o is a pointer to a non-nil extHandle.
rk := rt.Kind()
for rk == reflect.Ptr {
rt = rt.Elem()
rk = rt.Kind()
}
if rt.PkgPath() == "" || rk == reflect.Interface { // || rk == reflect.Ptr {
return fmt.Errorf("codec.Handle.SetExt: Takes named type, not a pointer or interface: %v", rt)
}
rtid := rt2id(rt)
switch rtid {
case timeTypId, rawTypId, rawExtTypId:
// all natively supported type, so cannot have an extension.
// However, we do not return an error for these, as we do not document that.
// Instead, we silently treat as a no-op, and return.
return
}
o2 := *o
for i := range o2 {
v := &o2[i]
if v.rtid == rtid {
v.tag, v.ext = tag, ext
return
}
}
rtidptr := rt2id(reflect.PtrTo(rt))
*o = append(o2, extTypeTagFn{rtid, rtidptr, rt, tag, ext}) // , [1]uint64{}})
return
}
func (o extHandle) getExt(rtid uintptr, check bool) (v *extTypeTagFn) {
if !check {
return
}
for i := range o {
v = &o[i]
if v.rtid == rtid || v.rtidptr == rtid {
return
}
}
return nil
}
func (o extHandle) getExtForTag(tag uint64) (v *extTypeTagFn) {
for i := range o {
v = &o[i]
if v.tag == tag {
return
}
}
return nil
}
type intf2impl struct {
rtid uintptr // for intf
impl reflect.Type
// _ [1]uint64 // padding // not-needed, as *intf2impl is never returned.
}
type intf2impls []intf2impl
// Intf2Impl maps an interface to an implementing type.
// This allows us support infering the concrete type
// and populating it when passed an interface.
// e.g. var v io.Reader can be decoded as a bytes.Buffer, etc.
//
// Passing a nil impl will clear the mapping.
func (o *intf2impls) Intf2Impl(intf, impl reflect.Type) (err error) {
if impl != nil && !impl.Implements(intf) {
return fmt.Errorf("Intf2Impl: %v does not implement %v", impl, intf)
}
rtid := rt2id(intf)
o2 := *o
for i := range o2 {
v := &o2[i]
if v.rtid == rtid {
v.impl = impl
return
}
}
*o = append(o2, intf2impl{rtid, impl})
return
}
func (o intf2impls) intf2impl(rtid uintptr) (rv reflect.Value) {
for i := range o {
v := &o[i]
if v.rtid == rtid {
if v.impl == nil {
return
}
vkind := v.impl.Kind()
if vkind == reflect.Ptr {
return reflect.New(v.impl.Elem())
}
return rvZeroAddrK(v.impl, vkind)
}
}
return
}
type structFieldInfoFlag uint8
const (
_ structFieldInfoFlag = 1 << iota
structFieldInfoFlagReady
structFieldInfoFlagOmitEmpty
)
func (x *structFieldInfoFlag) flagSet(f structFieldInfoFlag) {
*x = *x | f
}
func (x *structFieldInfoFlag) flagClr(f structFieldInfoFlag) {
*x = *x &^ f
}
func (x structFieldInfoFlag) flagGet(f structFieldInfoFlag) bool {
return x&f != 0
}
func (x structFieldInfoFlag) omitEmpty() bool {
return x.flagGet(structFieldInfoFlagOmitEmpty)
}
func (x structFieldInfoFlag) ready() bool {
return x.flagGet(structFieldInfoFlagReady)
}
type structFieldInfo struct {
encName string // encode name
fieldName string // field name
is [maxLevelsEmbedding]uint16 // (recursive/embedded) field index in struct
nis uint8 // num levels of embedding. if 1, then it's not embedded.
encNameAsciiAlphaNum bool // the encName only contains ascii alphabet and numbers
structFieldInfoFlag
// _ [1]byte // padding
}
// func (si *structFieldInfo) setToZeroValue(v reflect.Value) {
// if v, valid := si.field(v, false); valid {
// v.Set(reflect.Zero(v.Type()))
// }
// }
// rv returns the field of the struct.
// If anonymous, it returns an Invalid
func (si *structFieldInfo) field(v reflect.Value, update bool) (rv2 reflect.Value, valid bool) {
// replicate FieldByIndex
for i, x := range si.is {
if uint8(i) == si.nis {
break
}
if v, valid = baseStructRv(v, update); !valid {
return
}
v = v.Field(int(x))
}
return v, true
}
func parseStructInfo(stag string) (toArray, omitEmpty bool, keytype valueType) {
keytype = valueTypeString // default
if stag == "" {
return
}
for i, s := range strings.Split(stag, ",") {
if i == 0 {
} else {
switch s {
case "omitempty":
omitEmpty = true
case "toarray":
toArray = true
case "int":
keytype = valueTypeInt
case "uint":
keytype = valueTypeUint
case "float":
keytype = valueTypeFloat
// case "bool":
// keytype = valueTypeBool
case "string":
keytype = valueTypeString
}
}
}
return
}
func (si *structFieldInfo) parseTag(stag string) {
// if fname == "" {
// panic(errNoFieldNameToStructFieldInfo)
// }
if stag == "" {
return
}
for i, s := range strings.Split(stag, ",") {
if i == 0 {
if s != "" {
si.encName = s
}
} else {
switch s {
case "omitempty":
si.flagSet(structFieldInfoFlagOmitEmpty)
}
}
}
}
type sfiSortedByEncName []*structFieldInfo
func (p sfiSortedByEncName) Len() int { return len(p) }
func (p sfiSortedByEncName) Less(i, j int) bool { return p[uint(i)].encName < p[uint(j)].encName }
func (p sfiSortedByEncName) Swap(i, j int) { p[uint(i)], p[uint(j)] = p[uint(j)], p[uint(i)] }
const structFieldNodeNumToCache = 4
type structFieldNodeCache struct {
rv [structFieldNodeNumToCache]reflect.Value
idx [structFieldNodeNumToCache]uint32
num uint8
}
func (x *structFieldNodeCache) get(key uint32) (fv reflect.Value, valid bool) {
for i, k := range &x.idx {
if uint8(i) == x.num {
return // break
}
if key == k {
return x.rv[i], true
}
}
return
}
func (x *structFieldNodeCache) tryAdd(fv reflect.Value, key uint32) {
if x.num < structFieldNodeNumToCache {
x.rv[x.num] = fv
x.idx[x.num] = key
x.num++
return
}
}
type structFieldNode struct {
v reflect.Value
cache2 structFieldNodeCache
cache3 structFieldNodeCache
update bool
}
func (x *structFieldNode) field(si *structFieldInfo) (fv reflect.Value) {
// return si.fieldval(x.v, x.update)
// Note: we only cache if nis=2 or nis=3 i.e. up to 2 levels of embedding
// This mostly saves us time on the repeated calls to v.Elem, v.Field, etc.
var valid bool
switch si.nis {
case 1:
fv = x.v.Field(int(si.is[0]))
case 2:
if fv, valid = x.cache2.get(uint32(si.is[0])); valid {
fv = fv.Field(int(si.is[1]))
return
}
fv = x.v.Field(int(si.is[0]))
if fv, valid = baseStructRv(fv, x.update); !valid {
return
}
x.cache2.tryAdd(fv, uint32(si.is[0]))
fv = fv.Field(int(si.is[1]))
case 3:
var key uint32 = uint32(si.is[0])<<16 | uint32(si.is[1])
if fv, valid = x.cache3.get(key); valid {
fv = fv.Field(int(si.is[2]))
return
}
fv = x.v.Field(int(si.is[0]))
if fv, valid = baseStructRv(fv, x.update); !valid {
return
}
fv = fv.Field(int(si.is[1]))
if fv, valid = baseStructRv(fv, x.update); !valid {
return
}
x.cache3.tryAdd(fv, key)
fv = fv.Field(int(si.is[2]))
default:
fv, _ = si.field(x.v, x.update)
}
return
}
func baseStructRv(v reflect.Value, update bool) (v2 reflect.Value, valid bool) {
for v.Kind() == reflect.Ptr {
if rvIsNil(v) {
if !update {
return
}
rvSetDirect(v, reflect.New(v.Type().Elem()))
}
v = v.Elem()
}
return v, true
}
type tiflag uint32
const (
_ tiflag = 1 << iota
tiflagComparable
tiflagIsZeroer
tiflagIsZeroerPtr
tiflagBinaryMarshaler
tiflagBinaryMarshalerPtr
tiflagBinaryUnmarshaler
tiflagBinaryUnmarshalerPtr
tiflagTextMarshaler
tiflagTextMarshalerPtr
tiflagTextUnmarshaler
tiflagTextUnmarshalerPtr
tiflagJsonMarshaler
tiflagJsonMarshalerPtr
tiflagJsonUnmarshaler
tiflagJsonUnmarshalerPtr
tiflagSelfer
tiflagSelferPtr
tiflagMissingFielder
tiflagMissingFielderPtr
)
// typeInfo keeps static (non-changing readonly)information
// about each (non-ptr) type referenced in the encode/decode sequence.
//
// During an encode/decode sequence, we work as below:
// - If base is a built in type, en/decode base value
// - If base is registered as an extension, en/decode base value
// - If type is binary(M/Unm)arshaler, call Binary(M/Unm)arshal method
// - If type is text(M/Unm)arshaler, call Text(M/Unm)arshal method
// - Else decode appropriately based on the reflect.Kind
type typeInfo struct {
rt reflect.Type
elem reflect.Type
pkgpath string
rtid uintptr
numMeth uint16 // number of methods
kind uint8
chandir uint8
anyOmitEmpty bool // true if a struct, and any of the fields are tagged "omitempty"
toArray bool // whether this (struct) type should be encoded as an array
keyType valueType // if struct, how is the field name stored in a stream? default is string
mbs bool // base type (T or *T) is a MapBySlice
// ---- cpu cache line boundary?
sfiSort []*structFieldInfo // sorted. Used when enc/dec struct to map.
sfiSrc []*structFieldInfo // unsorted. Used when enc/dec struct to array.
key reflect.Type
// ---- cpu cache line boundary?
// sfis []structFieldInfo // all sfi, in src order, as created.
sfiNamesSort []byte // all names, with indexes into the sfiSort
// rv0 is the zero value for the type.
// It is mostly beneficial for all non-reference kinds
// i.e. all but map/chan/func/ptr/unsafe.pointer
// so beneficial for intXX, bool, slices, structs, etc
rv0 reflect.Value
elemsize uintptr
// other flags, with individual bits representing if set.
flags tiflag
infoFieldOmitempty bool
elemkind uint8
_ [2]byte // padding
// _ [1]uint64 // padding
}
func (ti *typeInfo) isFlag(f tiflag) bool {
return ti.flags&f != 0
}
func (ti *typeInfo) flag(when bool, f tiflag) *typeInfo {
if when {
ti.flags |= f
}
return ti
}
func (ti *typeInfo) indexForEncName(name []byte) (index int16) {
var sn []byte
if len(name)+2 <= 32 {
var buf [32]byte // should not escape to heap
sn = buf[:len(name)+2]
} else {
sn = make([]byte, len(name)+2)
}
copy(sn[1:], name)
sn[0], sn[len(sn)-1] = tiSep2(name), 0xff
j := bytes.Index(ti.sfiNamesSort, sn)
if j < 0 {
return -1
}
index = int16(uint16(ti.sfiNamesSort[j+len(sn)+1]) | uint16(ti.sfiNamesSort[j+len(sn)])<<8)
return
}
type rtid2ti struct {
rtid uintptr
ti *typeInfo
}
// TypeInfos caches typeInfo for each type on first inspection.
//
// It is configured with a set of tag keys, which are used to get
// configuration for the type.
type TypeInfos struct {
// infos: formerly map[uintptr]*typeInfo, now *[]rtid2ti, 2 words expected
infos atomicTypeInfoSlice
mu sync.Mutex
_ uint64 // padding (cache-aligned)
tags []string
_ uint64 // padding (cache-aligned)
}
// NewTypeInfos creates a TypeInfos given a set of struct tags keys.
//
// This allows users customize the struct tag keys which contain configuration
// of their types.
func NewTypeInfos(tags []string) *TypeInfos {
return &TypeInfos{tags: tags}
}
func (x *TypeInfos) structTag(t reflect.StructTag) (s string) {
// check for tags: codec, json, in that order.
// this allows seamless support for many configured structs.
for _, x := range x.tags {
s = t.Get(x)
if s != "" {
return s
}
}
return
}
func findTypeInfo(s []rtid2ti, rtid uintptr) (i uint, ti *typeInfo) {
// binary search. adapted from sort/search.go.
// Note: we use goto (instead of for loop) so this can be inlined.
// h, i, j := 0, 0, len(s)
var h uint // var h, i uint
var j = uint(len(s))
LOOP:
if i < j {
h = i + (j-i)/2
if s[h].rtid < rtid {
i = h + 1
} else {
j = h
}
goto LOOP
}
if i < uint(len(s)) && s[i].rtid == rtid {
ti = s[i].ti
}
return
}
func (x *TypeInfos) get(rtid uintptr, rt reflect.Type) (pti *typeInfo) {
sp := x.infos.load()
if sp != nil {
_, pti = findTypeInfo(sp, rtid)
if pti != nil {
return
}
}
rk := rt.Kind()
if rk == reflect.Ptr { // || (rk == reflect.Interface && rtid != intfTypId) {
halt.errorf("invalid kind passed to TypeInfos.get: %v - %v", rk, rt)
}
// do not hold lock while computing this.
// it may lead to duplication, but that's ok.
ti := typeInfo{
rt: rt,
rtid: rtid,
kind: uint8(rk),
pkgpath: rt.PkgPath(),
keyType: valueTypeString, // default it - so it's never 0
}
ti.rv0 = reflect.Zero(rt)
ti.numMeth = uint16(rt.NumMethod())
var b1, b2 bool
b1, b2 = implIntf(rt, binaryMarshalerTyp)
ti.flag(b1, tiflagBinaryMarshaler).flag(b2, tiflagBinaryMarshalerPtr)
b1, b2 = implIntf(rt, binaryUnmarshalerTyp)
ti.flag(b1, tiflagBinaryUnmarshaler).flag(b2, tiflagBinaryUnmarshalerPtr)
b1, b2 = implIntf(rt, textMarshalerTyp)
ti.flag(b1, tiflagTextMarshaler).flag(b2, tiflagTextMarshalerPtr)
b1, b2 = implIntf(rt, textUnmarshalerTyp)
ti.flag(b1, tiflagTextUnmarshaler).flag(b2, tiflagTextUnmarshalerPtr)
b1, b2 = implIntf(rt, jsonMarshalerTyp)
ti.flag(b1, tiflagJsonMarshaler).flag(b2, tiflagJsonMarshalerPtr)
b1, b2 = implIntf(rt, jsonUnmarshalerTyp)
ti.flag(b1, tiflagJsonUnmarshaler).flag(b2, tiflagJsonUnmarshalerPtr)
b1, b2 = implIntf(rt, selferTyp)
ti.flag(b1, tiflagSelfer).flag(b2, tiflagSelferPtr)
b1, b2 = implIntf(rt, missingFielderTyp)
ti.flag(b1, tiflagMissingFielder).flag(b2, tiflagMissingFielderPtr)
b1, b2 = implIntf(rt, iszeroTyp)
ti.flag(b1, tiflagIsZeroer).flag(b2, tiflagIsZeroerPtr)
b1 = rt.Comparable()
ti.flag(b1, tiflagComparable)
switch rk {
case reflect.Struct:
var omitEmpty bool
if f, ok := rt.FieldByName(structInfoFieldName); ok {
ti.toArray, omitEmpty, ti.keyType = parseStructInfo(x.structTag(f.Tag))
ti.infoFieldOmitempty = omitEmpty
} else {
ti.keyType = valueTypeString
}
pp, pi := &pool4tiload, pool4tiload.Get() // pool.tiLoad()
pv := pi.(*typeInfoLoadArray)
pv.etypes[0] = ti.rtid
// vv := typeInfoLoad{pv.fNames[:0], pv.encNames[:0], pv.etypes[:1], pv.sfis[:0]}
vv := typeInfoLoad{pv.etypes[:1], pv.sfis[:0]}
x.rget(rt, rtid, omitEmpty, nil, &vv)
ti.sfiSrc, ti.sfiSort, ti.sfiNamesSort, ti.anyOmitEmpty = rgetResolveSFI(rt, vv.sfis, pv)
pp.Put(pi)
case reflect.Map:
ti.elem = rt.Elem()
ti.key = rt.Key()
case reflect.Slice:
ti.mbs, _ = implIntf(rt, mapBySliceTyp)
ti.elem = rt.Elem()
ti.elemsize = ti.elem.Size()
ti.elemkind = uint8(ti.elem.Kind())
case reflect.Chan:
ti.elem = rt.Elem()
ti.chandir = uint8(rt.ChanDir())
case reflect.Array:
ti.elem = rt.Elem()
ti.elemsize = ti.elem.Size()
ti.elemkind = uint8(ti.elem.Kind())
case reflect.Ptr:
ti.elem = rt.Elem()
}
x.mu.Lock()
sp = x.infos.load()
var sp2 []rtid2ti
if sp == nil {
pti = &ti
sp2 = []rtid2ti{{rtid, pti}}
x.infos.store(sp2)
} else {
var idx uint
idx, pti = findTypeInfo(sp, rtid)
if pti == nil {
pti = &ti
sp2 = make([]rtid2ti, len(sp)+1)
copy(sp2, sp[:idx])
copy(sp2[idx+1:], sp[idx:])
sp2[idx] = rtid2ti{rtid, pti}
x.infos.store(sp2)
}
}
x.mu.Unlock()
return
}
func (x *TypeInfos) rget(rt reflect.Type, rtid uintptr, omitEmpty bool,
indexstack []uint16, pv *typeInfoLoad) {
// Read up fields and store how to access the value.
//
// It uses go's rules for message selectors,
// which say that the field with the shallowest depth is selected.
//
// Note: we consciously use slices, not a map, to simulate a set.
// Typically, types have < 16 fields,
// and iteration using equals is faster than maps there
flen := rt.NumField()
if flen > (1<<maxLevelsEmbedding - 1) {
halt.errorf("codec: types with > %v fields are not supported - has %v fields",
(1<<maxLevelsEmbedding - 1), flen)
}
// pv.sfis = make([]structFieldInfo, flen)
LOOP:
for j, jlen := uint16(0), uint16(flen); j < jlen; j++ {
f := rt.Field(int(j))
fkind := f.Type.Kind()
// skip if a func type, or is unexported, or structTag value == "-"
switch fkind {
case reflect.Func, reflect.Complex64, reflect.Complex128, reflect.UnsafePointer:
continue LOOP
}
isUnexported := f.PkgPath != ""
if isUnexported && !f.Anonymous {
continue
}
stag := x.structTag(f.Tag)
if stag == "-" {
continue
}
var si structFieldInfo
var parsed bool
// if anonymous and no struct tag (or it's blank),
// and a struct (or pointer to struct), inline it.
if f.Anonymous && fkind != reflect.Interface {
// ^^ redundant but ok: per go spec, an embedded pointer type cannot be to an interface
ft := f.Type
isPtr := ft.Kind() == reflect.Ptr
for ft.Kind() == reflect.Ptr {
ft = ft.Elem()
}
isStruct := ft.Kind() == reflect.Struct
// Ignore embedded fields of unexported non-struct types.
// Also, from go1.10, ignore pointers to unexported struct types
// because unmarshal cannot assign a new struct to an unexported field.
// See https://golang.org/issue/21357
if (isUnexported && !isStruct) || (!allowSetUnexportedEmbeddedPtr && isUnexported && isPtr) {
continue
}
doInline := stag == ""
if !doInline {
si.parseTag(stag)
parsed = true
doInline = si.encName == ""
// doInline = si.isZero()
}
if doInline && isStruct {
// if etypes contains this, don't call rget again (as fields are already seen here)
ftid := rt2id(ft)
// We cannot recurse forever, but we need to track other field depths.
// So - we break if we see a type twice (not the first time).
// This should be sufficient to handle an embedded type that refers to its
// owning type, which then refers to its embedded type.
processIt := true
numk := 0
for _, k := range pv.etypes {
if k == ftid {
numk++
if numk == rgetMaxRecursion {
processIt = false
break
}
}
}
if processIt {
pv.etypes = append(pv.etypes, ftid)
indexstack2 := make([]uint16, len(indexstack)+1)
copy(indexstack2, indexstack)
indexstack2[len(indexstack)] = j
// indexstack2 := append(append(make([]int, 0, len(indexstack)+4), indexstack...), j)
x.rget(ft, ftid, omitEmpty, indexstack2, pv)
}
continue
}
}
// after the anonymous dance: if an unexported field, skip
if isUnexported {
continue
}
if f.Name == "" {
panic(errNoFieldNameToStructFieldInfo)
}
// pv.fNames = append(pv.fNames, f.Name)
// if si.encName == "" {
if !parsed {
si.encName = f.Name
si.parseTag(stag)
parsed = true
} else if si.encName == "" {
si.encName = f.Name
}
si.encNameAsciiAlphaNum = true
for i := len(si.encName) - 1; i >= 0; i-- { // bounds-check elimination
b := si.encName[i]
if (b >= '0' && b <= '9') || (b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z') {
continue
}
si.encNameAsciiAlphaNum = false
break
}
si.fieldName = f.Name
si.flagSet(structFieldInfoFlagReady)
if len(indexstack) > maxLevelsEmbedding-1 {
halt.errorf("codec: only supports up to %v depth of embedding - type has %v depth",
maxLevelsEmbedding-1, len(indexstack))
}
si.nis = uint8(len(indexstack)) + 1
copy(si.is[:], indexstack)
si.is[len(indexstack)] = j
if omitEmpty {
si.flagSet(structFieldInfoFlagOmitEmpty)
}
pv.sfis = append(pv.sfis, si)
}
}
func tiSep(name string) uint8 {
// (xn[0]%64) // (between 192-255 - outside ascii BMP)
// Tried the following before settling on correct implementation:
// return 0xfe - (name[0] & 63)
// return 0xfe - (name[0] & 63) - uint8(len(name))
// return 0xfe - (name[0] & 63) - uint8(len(name)&63)
// return ((0xfe - (name[0] & 63)) & 0xf8) | (uint8(len(name) & 0x07))
return 0xfe - (name[0] & 63) - uint8(len(name)&63)
}
func tiSep2(name []byte) uint8 {
return 0xfe - (name[0] & 63) - uint8(len(name)&63)
}
// resolves the struct field info got from a call to rget.
// Returns a trimmed, unsorted and sorted []*structFieldInfo.
func rgetResolveSFI(rt reflect.Type, x []structFieldInfo, pv *typeInfoLoadArray) (
y, z []*structFieldInfo, ss []byte, anyOmitEmpty bool) {
sa := pv.sfiidx[:0]
sn := pv.b[:]
n := len(x)
var xn string
var ui uint16
var sep byte
for i := range x {
ui = uint16(i)
xn = x[i].encName // fieldName or encName? use encName for now.
if len(xn)+2 > cap(sn) {
sn = make([]byte, len(xn)+2)
} else {
sn = sn[:len(xn)+2]
}
// use a custom sep, so that misses are less frequent,
// since the sep (first char in search) is as unique as first char in field name.
sep = tiSep(xn)
sn[0], sn[len(sn)-1] = sep, 0xff
copy(sn[1:], xn)
j := bytes.Index(sa, sn)
if j == -1 {
sa = append(sa, sep)
sa = append(sa, xn...)
sa = append(sa, 0xff, byte(ui>>8), byte(ui))
} else {
index := uint16(sa[j+len(sn)+1]) | uint16(sa[j+len(sn)])<<8
// one of them must be cleared (reset to nil),
// and the index updated appropriately
i2clear := ui // index to be cleared
if x[i].nis < x[index].nis { // this one is shallower
// update the index to point to this later one.
sa[j+len(sn)], sa[j+len(sn)+1] = byte(ui>>8), byte(ui)
// clear the earlier one, as this later one is shallower.
i2clear = index
}
if x[i2clear].ready() {
x[i2clear].flagClr(structFieldInfoFlagReady)
n--
}
}
}
var w []structFieldInfo
sharingArray := len(x) <= typeInfoLoadArraySfisLen // sharing array with typeInfoLoadArray
if sharingArray {
w = make([]structFieldInfo, n)
}
// remove all the nils (non-ready)
y = make([]*structFieldInfo, n)
n = 0
var sslen int
for i := range x {
if !x[i].ready() {
continue
}
if !anyOmitEmpty && x[i].omitEmpty() {
anyOmitEmpty = true
}
if sharingArray {
w[n] = x[i]
y[n] = &w[n]
} else {
y[n] = &x[i]
}
sslen = sslen + len(x[i].encName) + 4
n++
}
if n != len(y) {
halt.errorf("failure reading struct %v - expecting %d of %d valid fields, got %d",
rt, len(y), len(x), n)
}
z = make([]*structFieldInfo, len(y))
copy(z, y)
sort.Sort(sfiSortedByEncName(z))
sharingArray = len(sa) <= typeInfoLoadArraySfiidxLen
if sharingArray {
ss = make([]byte, 0, sslen)
} else {
ss = sa[:0] // reuse the newly made sa array if necessary
}
for i := range z {
xn = z[i].encName
sep = tiSep(xn)
ui = uint16(i)
ss = append(ss, sep)
ss = append(ss, xn...)
ss = append(ss, 0xff, byte(ui>>8), byte(ui))
}
return
}
func implIntf(rt, iTyp reflect.Type) (base bool, indir bool) {
return rt.Implements(iTyp), reflect.PtrTo(rt).Implements(iTyp)
}
// isEmptyStruct is only called from isEmptyValue, and checks if a struct is empty:
// - does it implement IsZero() bool
// - is it comparable, and can i compare directly using ==
// - if checkStruct, then walk through the encodable fields
// and check if they are empty or not.
func isEmptyStruct(v reflect.Value, tinfos *TypeInfos, deref, checkStruct bool) bool {
// v is a struct kind - no need to check again.
// We only check isZero on a struct kind, to reduce the amount of times
// that we lookup the rtid and typeInfo for each type as we walk the tree.
vt := v.Type()
rtid := rt2id(vt)
if tinfos == nil {
tinfos = defTypeInfos
}
ti := tinfos.get(rtid, vt)
if ti.rtid == timeTypId {
return rv2i(v).(time.Time).IsZero()
}
if ti.isFlag(tiflagIsZeroerPtr) && v.CanAddr() {
return rv2i(v.Addr()).(isZeroer).IsZero()
}
if ti.isFlag(tiflagIsZeroer) {
return rv2i(v).(isZeroer).IsZero()
}
if ti.isFlag(tiflagComparable) {
return rv2i(v) == rv2i(reflect.Zero(vt))
}
if !checkStruct {
return false
}
// We only care about what we can encode/decode,
// so that is what we use to check omitEmpty.
for _, si := range ti.sfiSrc {
sfv, valid := si.field(v, false)
if valid && !isEmptyValue(sfv, tinfos, deref, checkStruct) {
return false
}
}
return true
}
// func roundFloat(x float64) float64 {
// t := math.Trunc(x)
// if math.Abs(x-t) >= 0.5 {
// return t + math.Copysign(1, x)
// }
// return t
// }
func panicToErr(h errDecorator, err *error) {
// Note: This method MUST be called directly from defer i.e. defer panicToErr ...
// else it seems the recover is not fully handled
if recoverPanicToErr {
if x := recover(); x != nil {
// fmt.Printf("panic'ing with: %v\n", x)
// debug.PrintStack()
panicValToErr(h, x, err)
}
}
}
func isSliceBoundsError(s string) bool {
return strings.Contains(s, "index out of range") ||
strings.Contains(s, "slice bounds out of range")
}
func panicValToErr(h errDecorator, v interface{}, err *error) {
d, dok := h.(*Decoder)
switch xerr := v.(type) {
case nil:
case error:
switch xerr {
case nil:
case io.EOF, io.ErrUnexpectedEOF, errEncoderNotInitialized, errDecoderNotInitialized:
// treat as special (bubble up)
*err = xerr
default:
if dok && d.bytes && isSliceBoundsError(xerr.Error()) {
*err = io.EOF
} else {
h.wrapErr(xerr, err)
}
}
case string:
if xerr != "" {
if dok && d.bytes && isSliceBoundsError(xerr) {
*err = io.EOF
} else {
h.wrapErr(xerr, err)
}
}
case fmt.Stringer:
if xerr != nil {
h.wrapErr(xerr, err)
}
default:
h.wrapErr(v, err)
}
}
func isImmutableKind(k reflect.Kind) (v bool) {
// return immutableKindsSet[k]
// since we know reflect.Kind is in range 0..31, then use the k%32 == k constraint
return immutableKindsSet[k%reflect.Kind(len(immutableKindsSet))] // bounds-check-elimination
}
func usableByteSlice(bs []byte, slen int) []byte {
if cap(bs) >= slen {
if bs == nil {
return []byte{}
}
return bs[:slen]
}
return make([]byte, slen)
}
// ----
type codecFnInfo struct {
ti *typeInfo
xfFn Ext
xfTag uint64
seq seqType
addrD bool
addrF bool // if addrD, this says whether decode function can take a value or a ptr
addrE bool
}
// codecFn encapsulates the captured variables and the encode function.
// This way, we only do some calculations one times, and pass to the
// code block that should be called (encapsulated in a function)
// instead of executing the checks every time.
type codecFn struct {
i codecFnInfo
fe func(*Encoder, *codecFnInfo, reflect.Value)
fd func(*Decoder, *codecFnInfo, reflect.Value)
_ [1]uint64 // padding (cache-aligned)
}
type codecRtidFn struct {
rtid uintptr
fn *codecFn
}
func makeExt(ext interface{}) Ext {
if ext == nil {
return &extFailWrapper{}
}
switch t := ext.(type) {
case nil:
return &extFailWrapper{}
case Ext:
return t
case BytesExt:
return &bytesExtWrapper{BytesExt: t}
case InterfaceExt:
return &interfaceExtWrapper{InterfaceExt: t}
}
return &extFailWrapper{}
}
func baseRV(v interface{}) (rv reflect.Value) {
for rv = rv4i(v); rv.Kind() == reflect.Ptr; rv = rv.Elem() {
}
return
}
// ----
// these "checkOverflow" functions must be inlinable, and not call anybody.
// Overflow means that the value cannot be represented without wrapping/overflow.
// Overflow=false does not mean that the value can be represented without losing precision
// (especially for floating point).
type checkOverflow struct{}
// func (checkOverflow) Float16(f float64) (overflow bool) {
// halt.errorf("unimplemented")
// if f < 0 {
// f = -f
// }
// return math.MaxFloat32 < f && f <= math.MaxFloat64
// }
func (checkOverflow) Float32(v float64) (overflow bool) {
if v < 0 {
v = -v
}
return math.MaxFloat32 < v && v <= math.MaxFloat64
}
func (checkOverflow) Uint(v uint64, bitsize uint8) (overflow bool) {
// if bitsize == 0 || bitsize >= 64 || v == 0 {
// if v == 0 {
// return
// }
// if trunc := (v << (64 - bitsize)) >> (64 - bitsize); v != trunc {
if v != 0 && v != (v<<(64-bitsize))>>(64-bitsize) {
overflow = true
}
return
}
func (checkOverflow) Int(v int64, bitsize uint8) (overflow bool) {
// if bitsize == 0 || bitsize >= 64 || v == 0 {
// if v == 0 {
// return
// }
// if trunc := (v << (64 - bitsize)) >> (64 - bitsize); v != trunc {
// overflow = true
// }
if v != 0 && v != (v<<(64-bitsize))>>(64-bitsize) {
overflow = true
}
return
}
func (checkOverflow) Uint2Int(v uint64, neg bool) (overflow bool) {
return (neg && v > 1<<63) || (!neg && v >= 1<<63)
}
func (checkOverflow) SignedInt(v uint64) (overflow bool) {
//e.g. -127 to 128 for int8
pos := (v >> 63) == 0
ui2 := v & 0x7fffffffffffffff
if pos {
if ui2 > math.MaxInt64 {
overflow = true
}
} else {
if ui2 > math.MaxInt64-1 {
overflow = true
}
}
return
}
func (x checkOverflow) Float32V(v float64) float64 {
if x.Float32(v) {
halt.errorf("float32 overflow: %v", v)
}
return v
}
func (x checkOverflow) UintV(v uint64, bitsize uint8) uint64 {
if x.Uint(v, bitsize) {
halt.errorf("uint64 overflow: %v", v)
}
return v
}
func (x checkOverflow) IntV(v int64, bitsize uint8) int64 {
if x.Int(v, bitsize) {
halt.errorf("int64 overflow: %v", v)
}
return v
}
func (x checkOverflow) SignedIntV(v uint64) int64 {
if x.SignedInt(v) {
halt.errorf("uint64 to int64 overflow: %v", v)
}
return int64(v)
}
// ------------------ FLOATING POINT -----------------
func isNaN64(f float64) bool { return f != f }
func isNaN32(f float32) bool { return f != f }
func abs32(f float32) float32 {
return math.Float32frombits(math.Float32bits(f) &^ (1 << 31))
}
// Per go spec, floats are represented in memory as
// IEEE single or double precision floating point values.
//
// We also looked at the source for stdlib math/modf.go,
// reviewed https://github.com/chewxy/math32
// and read wikipedia documents describing the formats.
//
// It became clear that we could easily look at the bits to determine
// whether any fraction exists.
//
// This is all we need for now.
func noFrac64(f float64) (v bool) {
x := math.Float64bits(f)
e := uint64(x>>52)&0x7FF - 1023 // uint(x>>shift)&mask - bias
// clear top 12+e bits, the integer part; if the rest is 0, then no fraction.
if e < 52 {
// return x&((1<<64-1)>>(12+e)) == 0
return x<<(12+e) == 0
}
return
}
func noFrac32(f float32) (v bool) {
x := math.Float32bits(f)
e := uint32(x>>23)&0xFF - 127 // uint(x>>shift)&mask - bias
// clear top 9+e bits, the integer part; if the rest is 0, then no fraction.
if e < 23 {
// return x&((1<<32-1)>>(9+e)) == 0
return x<<(9+e) == 0
}
return
}
func isWhitespaceChar(v byte) bool {
// these are in order of speed below ...
return v < 33
// return v < 33 && whitespaceCharBitset64.isset(v)
// return v < 33 && (v == ' ' || v == '\n' || v == '\t' || v == '\r')
// return v == ' ' || v == '\n' || v == '\t' || v == '\r'
// return whitespaceCharBitset.isset(v)
}
func isNumberChar(v byte) bool {
// these are in order of speed below ...
return numCharBitset.isset(v)
// return v < 64 && numCharNoExpBitset64.isset(v) || v == 'e' || v == 'E'
// return v > 42 && v < 102 && numCharWithExpBitset64.isset(v-42)
}
func isDigitChar(v byte) bool {
// these are in order of speed below ...
return digitCharBitset.isset(v)
// return v >= '0' && v <= '9'
}
// func noFrac(f float64) bool {
// _, frac := math.Modf(float64(f))
// return frac == 0
// }
// -----------------------
type ioFlusher interface {
Flush() error
}
type ioPeeker interface {
Peek(int) ([]byte, error)
}
type ioBuffered interface {
Buffered() int
}
// -----------------------
type sfiRv struct {
v *structFieldInfo
r reflect.Value
}
// -----------------
type set []interface{}
func (s *set) add(v interface{}) (exists bool) {
// e.ci is always nil, or len >= 1
x := *s
if x == nil {
x = make([]interface{}, 1, 8)
x[0] = v
*s = x
return
}
// typically, length will be 1. make this perform.
if len(x) == 1 {
if j := x[0]; j == 0 {
x[0] = v
} else if j == v {
exists = true
} else {
x = append(x, v)
*s = x
}
return
}
// check if it exists
for _, j := range x {
if j == v {
exists = true
return
}
}
// try to replace a "deleted" slot
for i, j := range x {
if j == 0 {
x[i] = v
return
}
}
// if unable to replace deleted slot, just append it.
x = append(x, v)
*s = x
return
}
func (s *set) remove(v interface{}) (exists bool) {
x := *s
if len(x) == 0 {
return
}
if len(x) == 1 {
if x[0] == v {
x[0] = 0
}
return
}
for i, j := range x {
if j == v {
exists = true
x[i] = 0 // set it to 0, as way to delete it.
// copy(x[i:], x[i+1:])
// x = x[:len(x)-1]
return
}
}
return
}
// ------
// bitset types are better than [256]bool, because they permit the whole
// bitset array being on a single cache line and use less memory.
//
// Also, since pos is a byte (0-255), there's no bounds checks on indexing (cheap).
//
// We previously had bitset128 [16]byte, and bitset32 [4]byte, but those introduces
// bounds checking, so we discarded them, and everyone uses bitset256.
//
// given x > 0 and n > 0 and x is exactly 2^n, then pos/x === pos>>n AND pos%x === pos&(x-1).
// consequently, pos/32 === pos>>5, pos/16 === pos>>4, pos/8 === pos>>3, pos%8 == pos&7
// type bitset256 [32]byte
// func (x *bitset256) set(pos byte) {
// x[pos>>3] |= (1 << (pos & 7))
// }
// func (x *bitset256) check(pos byte) uint8 {
// return x[pos>>3] & (1 << (pos & 7))
// }
// func (x *bitset256) isset(pos byte) bool {
// return x.check(pos) != 0
// // return x[pos>>3]&(1<<(pos&7)) != 0
// }
// func (x *bitset256) isnotset(pos byte) bool {
// return x.check(pos) == 0
// }
// type bitset256 [4]uint64
// func (x *bitset256) set(pos byte) {
// x[pos>>6] |= (1 << (pos & 63))
// }
// func (x *bitset256) check(pos byte) uint64 {
// return x[pos>>6] & (1 << (pos & 63))
// }
// func (x *bitset256) isset(pos byte) bool {
// return x.check(pos) != 0
// }
// func (x *bitset256) isnotset(pos byte) bool {
// return x.check(pos) == 0
// }
type bitset256 [256]bool
func (x *bitset256) set(pos byte) {
x[pos] = true
}
func (x *bitset256) isset(pos byte) bool {
return x[pos]
}
func (x *bitset256) isnotset(pos byte) bool {
return !x[pos]
}
type bitset32 uint32
func (x bitset32) set(pos byte) bitset32 {
return x | (1 << pos)
}
func (x bitset32) check(pos byte) uint32 {
return uint32(x) & (1 << pos)
}
func (x bitset32) isset(pos byte) bool {
return x.check(pos) != 0
}
func (x bitset32) isnotset(pos byte) bool {
return x.check(pos) == 0
}
type bitset64 uint64
func (x bitset64) set(pos byte) bitset64 {
return x | (1 << pos)
}
func (x bitset64) check(pos byte) uint64 {
return uint64(x) & (1 << pos)
}
func (x bitset64) isset(pos byte) bool {
return x.check(pos) != 0
}
func (x bitset64) isnotset(pos byte) bool {
return x.check(pos) == 0
}
// func (x *bitset256) unset(pos byte) {
// x[pos>>3] &^= (1 << (pos & 7))
// }
// type bit2set256 [64]byte
// func (x *bit2set256) set(pos byte, v1, v2 bool) {
// var pos2 uint8 = (pos & 3) << 1 // returning 0, 2, 4 or 6
// if v1 {
// x[pos>>2] |= 1 << (pos2 + 1)
// }
// if v2 {
// x[pos>>2] |= 1 << pos2
// }
// }
// func (x *bit2set256) get(pos byte) uint8 {
// var pos2 uint8 = (pos & 3) << 1 // returning 0, 2, 4 or 6
// return x[pos>>2] << (6 - pos2) >> 6 // 11000000 -> 00000011
// }
// ------------
type panicHdl struct{}
func (panicHdl) errorv(err error) {
if err != nil {
panic(err)
}
}
func (panicHdl) errorstr(message string) {
if message != "" {
panic(message)
}
}
func (panicHdl) errorf(format string, params ...interface{}) {
if len(params) != 0 {
panic(fmt.Sprintf(format, params...))
}
if len(params) == 0 {
panic(format)
}
panic("undefined error")
}
// ----------------------------------------------------
type errDecorator interface {
wrapErr(in interface{}, out *error)
}
type errDecoratorDef struct{}
func (errDecoratorDef) wrapErr(v interface{}, e *error) { *e = fmt.Errorf("%v", v) }
// ----------------------------------------------------
type must struct{}
func (must) String(s string, err error) string {
if err != nil {
halt.errorv(err)
}
return s
}
func (must) Int(s int64, err error) int64 {
if err != nil {
halt.errorv(err)
}
return s
}
func (must) Uint(s uint64, err error) uint64 {
if err != nil {
halt.errorv(err)
}
return s
}
func (must) Float(s float64, err error) float64 {
if err != nil {
halt.errorv(err)
}
return s
}
// -------------------
func freelistCapacity(length int) (capacity int) {
for capacity = 8; capacity < length; capacity *= 2 {
}
return
}
type bytesFreelist [][]byte
func (x *bytesFreelist) get(length int) (out []byte) {
var j int = -1
for i := 0; i < len(*x); i++ {
if cap((*x)[i]) >= length && (j == -1 || cap((*x)[j]) > cap((*x)[i])) {
j = i
}
}
if j == -1 {
return make([]byte, length, freelistCapacity(length))
}
out = (*x)[j][:length]
(*x)[j] = nil
for i := 0; i < len(out); i++ {
out[i] = 0
}
return
}
func (x *bytesFreelist) put(v []byte) {
if len(v) == 0 {
return
}
for i := 0; i < len(*x); i++ {
if cap((*x)[i]) == 0 {
(*x)[i] = v
return
}
}
*x = append(*x, v)
}
func (x *bytesFreelist) check(v []byte, length int) (out []byte) {
if cap(v) < length {
x.put(v)
return x.get(length)
}
return v[:length]
}
// -------------------------
type sfiRvFreelist [][]sfiRv
func (x *sfiRvFreelist) get(length int) (out []sfiRv) {
var j int = -1
for i := 0; i < len(*x); i++ {
if cap((*x)[i]) >= length && (j == -1 || cap((*x)[j]) > cap((*x)[i])) {
j = i
}
}
if j == -1 {
return make([]sfiRv, length, freelistCapacity(length))
}
out = (*x)[j][:length]
(*x)[j] = nil
for i := 0; i < len(out); i++ {
out[i] = sfiRv{}
}
return
}
func (x *sfiRvFreelist) put(v []sfiRv) {
for i := 0; i < len(*x); i++ {
if cap((*x)[i]) == 0 {
(*x)[i] = v
return
}
}
*x = append(*x, v)
}
// -----------
// xdebugf printf. the message in red on the terminal.
// Use it in place of fmt.Printf (which it calls internally)
func xdebugf(pattern string, args ...interface{}) {
xdebugAnyf("31", pattern, args...)
}
// xdebug2f printf. the message in blue on the terminal.
// Use it in place of fmt.Printf (which it calls internally)
func xdebug2f(pattern string, args ...interface{}) {
xdebugAnyf("34", pattern, args...)
}
func xdebugAnyf(colorcode, pattern string, args ...interface{}) {
if !xdebug {
return
}
var delim string
if len(pattern) > 0 && pattern[len(pattern)-1] != '\n' {
delim = "\n"
}
fmt.Printf("\033[1;"+colorcode+"m"+pattern+delim+"\033[0m", args...)
// os.Stderr.Flush()
}
// register these here, so that staticcheck stops barfing
var _ = xdebug2f
var _ = xdebugf
var _ = isNaN32
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