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// BSON library for Go
//
// Copyright (c) 2010-2012 - Gustavo Niemeyer <gustavo@niemeyer.net>
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this
// list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// gobson - BSON library for Go.
package bson
import (
"fmt"
"math"
"net/url"
"reflect"
"strconv"
"sync"
"time"
)
type decoder struct {
in []byte
i int
docType reflect.Type
}
var typeM = reflect.TypeOf(M{})
func newDecoder(in []byte) *decoder {
return &decoder{in, 0, typeM}
}
// --------------------------------------------------------------------------
// Some helper functions.
func corrupted() {
panic("Document is corrupted")
}
func settableValueOf(i interface{}) reflect.Value {
v := reflect.ValueOf(i)
sv := reflect.New(v.Type()).Elem()
sv.Set(v)
return sv
}
// --------------------------------------------------------------------------
// Unmarshaling of documents.
const (
setterUnknown = iota
setterNone
setterType
setterAddr
)
var setterStyles map[reflect.Type]int
var setterIface reflect.Type
var setterMutex sync.RWMutex
func init() {
var iface Setter
setterIface = reflect.TypeOf(&iface).Elem()
setterStyles = make(map[reflect.Type]int)
}
func setterStyle(outt reflect.Type) int {
setterMutex.RLock()
style := setterStyles[outt]
setterMutex.RUnlock()
if style == setterUnknown {
setterMutex.Lock()
defer setterMutex.Unlock()
if outt.Implements(setterIface) {
setterStyles[outt] = setterType
} else if reflect.PtrTo(outt).Implements(setterIface) {
setterStyles[outt] = setterAddr
} else {
setterStyles[outt] = setterNone
}
style = setterStyles[outt]
}
return style
}
func getSetter(outt reflect.Type, out reflect.Value) Setter {
style := setterStyle(outt)
if style == setterNone {
return nil
}
if style == setterAddr {
if !out.CanAddr() {
return nil
}
out = out.Addr()
} else if outt.Kind() == reflect.Ptr && out.IsNil() {
out.Set(reflect.New(outt.Elem()))
}
return out.Interface().(Setter)
}
func clearMap(m reflect.Value) {
var none reflect.Value
for _, k := range m.MapKeys() {
m.SetMapIndex(k, none)
}
}
func (d *decoder) readDocTo(out reflect.Value) {
var elemType reflect.Type
outt := out.Type()
outk := outt.Kind()
for {
if outk == reflect.Ptr && out.IsNil() {
out.Set(reflect.New(outt.Elem()))
}
if setter := getSetter(outt, out); setter != nil {
var raw Raw
d.readDocTo(reflect.ValueOf(&raw))
err := setter.SetBSON(raw)
if _, ok := err.(*TypeError); err != nil && !ok {
panic(err)
}
return
}
if outk == reflect.Ptr {
out = out.Elem()
outt = out.Type()
outk = out.Kind()
continue
}
break
}
var fieldsMap map[string]fieldInfo
var inlineMap reflect.Value
start := d.i
origout := out
if outk == reflect.Interface {
if d.docType.Kind() == reflect.Map {
mv := reflect.MakeMap(d.docType)
out.Set(mv)
out = mv
} else {
dv := reflect.New(d.docType).Elem()
out.Set(dv)
out = dv
}
outt = out.Type()
outk = outt.Kind()
}
docType := d.docType
keyType := typeString
convertKey := false
switch outk {
case reflect.Map:
keyType = outt.Key()
if keyType.Kind() != reflect.String {
panic("BSON map must have string keys. Got: " + outt.String())
}
if keyType != typeString {
convertKey = true
}
elemType = outt.Elem()
if elemType == typeIface {
d.docType = outt
}
if out.IsNil() {
out.Set(reflect.MakeMap(out.Type()))
} else if out.Len() > 0 {
clearMap(out)
}
case reflect.Struct:
if outt != typeRaw {
sinfo, err := getStructInfo(out.Type())
if err != nil {
panic(err)
}
fieldsMap = sinfo.FieldsMap
out.Set(sinfo.Zero)
if sinfo.InlineMap != -1 {
inlineMap = out.Field(sinfo.InlineMap)
if !inlineMap.IsNil() && inlineMap.Len() > 0 {
clearMap(inlineMap)
}
elemType = inlineMap.Type().Elem()
if elemType == typeIface {
d.docType = inlineMap.Type()
}
}
}
case reflect.Slice:
switch outt.Elem() {
case typeDocElem:
origout.Set(d.readDocElems(outt))
return
case typeRawDocElem:
origout.Set(d.readRawDocElems(outt))
return
}
fallthrough
default:
panic("Unsupported document type for unmarshalling: " + out.Type().String())
}
end := int(d.readInt32())
end += d.i - 4
if end <= d.i || end > len(d.in) || d.in[end-1] != '\x00' {
corrupted()
}
for d.in[d.i] != '\x00' {
kind := d.readByte()
name := d.readCStr()
if d.i >= end {
corrupted()
}
switch outk {
case reflect.Map:
e := reflect.New(elemType).Elem()
if d.readElemTo(e, kind) {
k := reflect.ValueOf(name)
if convertKey {
k = k.Convert(keyType)
}
out.SetMapIndex(k, e)
}
case reflect.Struct:
if outt == typeRaw {
d.dropElem(kind)
} else {
if info, ok := fieldsMap[name]; ok {
if info.Inline == nil {
d.readElemTo(out.Field(info.Num), kind)
} else {
d.readElemTo(out.FieldByIndex(info.Inline), kind)
}
} else if inlineMap.IsValid() {
if inlineMap.IsNil() {
inlineMap.Set(reflect.MakeMap(inlineMap.Type()))
}
e := reflect.New(elemType).Elem()
if d.readElemTo(e, kind) {
inlineMap.SetMapIndex(reflect.ValueOf(name), e)
}
} else {
d.dropElem(kind)
}
}
case reflect.Slice:
}
if d.i >= end {
corrupted()
}
}
d.i++ // '\x00'
if d.i != end {
corrupted()
}
d.docType = docType
if outt == typeRaw {
out.Set(reflect.ValueOf(Raw{0x03, d.in[start:d.i]}))
}
}
func (d *decoder) readArrayDocTo(out reflect.Value) {
end := int(d.readInt32())
end += d.i - 4
if end <= d.i || end > len(d.in) || d.in[end-1] != '\x00' {
corrupted()
}
i := 0
l := out.Len()
for d.in[d.i] != '\x00' {
if i >= l {
panic("Length mismatch on array field")
}
kind := d.readByte()
for d.i < end && d.in[d.i] != '\x00' {
d.i++
}
if d.i >= end {
corrupted()
}
d.i++
d.readElemTo(out.Index(i), kind)
if d.i >= end {
corrupted()
}
i++
}
if i != l {
panic("Length mismatch on array field")
}
d.i++ // '\x00'
if d.i != end {
corrupted()
}
}
func (d *decoder) readSliceDoc(t reflect.Type) interface{} {
tmp := make([]reflect.Value, 0, 8)
elemType := t.Elem()
if elemType == typeRawDocElem {
d.dropElem(0x04)
return reflect.Zero(t).Interface()
}
end := int(d.readInt32())
end += d.i - 4
if end <= d.i || end > len(d.in) || d.in[end-1] != '\x00' {
corrupted()
}
for d.in[d.i] != '\x00' {
kind := d.readByte()
for d.i < end && d.in[d.i] != '\x00' {
d.i++
}
if d.i >= end {
corrupted()
}
d.i++
e := reflect.New(elemType).Elem()
if d.readElemTo(e, kind) {
tmp = append(tmp, e)
}
if d.i >= end {
corrupted()
}
}
d.i++ // '\x00'
if d.i != end {
corrupted()
}
n := len(tmp)
slice := reflect.MakeSlice(t, n, n)
for i := 0; i != n; i++ {
slice.Index(i).Set(tmp[i])
}
return slice.Interface()
}
var typeSlice = reflect.TypeOf([]interface{}{})
var typeIface = typeSlice.Elem()
func (d *decoder) readDocElems(typ reflect.Type) reflect.Value {
docType := d.docType
d.docType = typ
slice := make([]DocElem, 0, 8)
d.readDocWith(func(kind byte, name string) {
e := DocElem{Name: name}
v := reflect.ValueOf(&e.Value)
if d.readElemTo(v.Elem(), kind) {
slice = append(slice, e)
}
})
slicev := reflect.New(typ).Elem()
slicev.Set(reflect.ValueOf(slice))
d.docType = docType
return slicev
}
func (d *decoder) readRawDocElems(typ reflect.Type) reflect.Value {
docType := d.docType
d.docType = typ
slice := make([]RawDocElem, 0, 8)
d.readDocWith(func(kind byte, name string) {
e := RawDocElem{Name: name}
v := reflect.ValueOf(&e.Value)
if d.readElemTo(v.Elem(), kind) {
slice = append(slice, e)
}
})
slicev := reflect.New(typ).Elem()
slicev.Set(reflect.ValueOf(slice))
d.docType = docType
return slicev
}
func (d *decoder) readDocWith(f func(kind byte, name string)) {
end := int(d.readInt32())
end += d.i - 4
if end <= d.i || end > len(d.in) || d.in[end-1] != '\x00' {
corrupted()
}
for d.in[d.i] != '\x00' {
kind := d.readByte()
name := d.readCStr()
if d.i >= end {
corrupted()
}
f(kind, name)
if d.i >= end {
corrupted()
}
}
d.i++ // '\x00'
if d.i != end {
corrupted()
}
}
// --------------------------------------------------------------------------
// Unmarshaling of individual elements within a document.
var blackHole = settableValueOf(struct{}{})
func (d *decoder) dropElem(kind byte) {
d.readElemTo(blackHole, kind)
}
// Attempt to decode an element from the document and put it into out.
// If the types are not compatible, the returned ok value will be
// false and out will be unchanged.
func (d *decoder) readElemTo(out reflect.Value, kind byte) (good bool) {
start := d.i
if kind == 0x03 {
// Delegate unmarshaling of documents.
outt := out.Type()
outk := out.Kind()
switch outk {
case reflect.Interface, reflect.Ptr, reflect.Struct, reflect.Map:
d.readDocTo(out)
return true
}
if setterStyle(outt) != setterNone {
d.readDocTo(out)
return true
}
if outk == reflect.Slice {
switch outt.Elem() {
case typeDocElem:
out.Set(d.readDocElems(outt))
case typeRawDocElem:
out.Set(d.readRawDocElems(outt))
}
return true
}
d.readDocTo(blackHole)
return true
}
var in interface{}
switch kind {
case 0x01: // Float64
in = d.readFloat64()
case 0x02: // UTF-8 string
in = d.readStr()
case 0x03: // Document
panic("Can't happen. Handled above.")
case 0x04: // Array
outt := out.Type()
if setterStyle(outt) != setterNone {
// Skip the value so its data is handed to the setter below.
d.dropElem(kind)
break
}
for outt.Kind() == reflect.Ptr {
outt = outt.Elem()
}
switch outt.Kind() {
case reflect.Array:
d.readArrayDocTo(out)
return true
case reflect.Slice:
in = d.readSliceDoc(outt)
default:
in = d.readSliceDoc(typeSlice)
}
case 0x05: // Binary
b := d.readBinary()
if b.Kind == 0x00 || b.Kind == 0x02 {
in = b.Data
} else {
in = b
}
case 0x06: // Undefined (obsolete, but still seen in the wild)
in = Undefined
case 0x07: // ObjectId
in = ObjectId(d.readBytes(12))
case 0x08: // Bool
in = d.readBool()
case 0x09: // Timestamp
// MongoDB handles timestamps as milliseconds.
i := d.readInt64()
if i == -62135596800000 {
in = time.Time{} // In UTC for convenience.
} else {
in = time.Unix(i/1e3, i%1e3*1e6)
}
case 0x0A: // Nil
in = nil
case 0x0B: // RegEx
in = d.readRegEx()
case 0x0C:
in = DBPointer{Namespace: d.readStr(), Id: ObjectId(d.readBytes(12))}
case 0x0D: // JavaScript without scope
in = JavaScript{Code: d.readStr()}
case 0x0E: // Symbol
in = Symbol(d.readStr())
case 0x0F: // JavaScript with scope
d.i += 4 // Skip length
js := JavaScript{d.readStr(), make(M)}
d.readDocTo(reflect.ValueOf(js.Scope))
in = js
case 0x10: // Int32
in = int(d.readInt32())
case 0x11: // Mongo-specific timestamp
in = MongoTimestamp(d.readInt64())
case 0x12: // Int64
in = d.readInt64()
case 0x7F: // Max key
in = MaxKey
case 0xFF: // Min key
in = MinKey
default:
panic(fmt.Sprintf("Unknown element kind (0x%02X)", kind))
}
outt := out.Type()
if outt == typeRaw {
out.Set(reflect.ValueOf(Raw{kind, d.in[start:d.i]}))
return true
}
if setter := getSetter(outt, out); setter != nil {
err := setter.SetBSON(Raw{kind, d.in[start:d.i]})
if err == SetZero {
out.Set(reflect.Zero(outt))
return true
}
if err == nil {
return true
}
if _, ok := err.(*TypeError); !ok {
panic(err)
}
return false
}
if in == nil {
out.Set(reflect.Zero(outt))
return true
}
outk := outt.Kind()
// Dereference and initialize pointer if necessary.
first := true
for outk == reflect.Ptr {
if !out.IsNil() {
out = out.Elem()
} else {
elem := reflect.New(outt.Elem())
if first {
// Only set if value is compatible.
first = false
defer func(out, elem reflect.Value) {
if good {
out.Set(elem)
}
}(out, elem)
} else {
out.Set(elem)
}
out = elem
}
outt = out.Type()
outk = outt.Kind()
}
inv := reflect.ValueOf(in)
if outt == inv.Type() {
out.Set(inv)
return true
}
switch outk {
case reflect.Interface:
out.Set(inv)
return true
case reflect.String:
switch inv.Kind() {
case reflect.String:
out.SetString(inv.String())
return true
case reflect.Slice:
if b, ok := in.([]byte); ok {
out.SetString(string(b))
return true
}
case reflect.Int, reflect.Int64:
if outt == typeJSONNumber {
out.SetString(strconv.FormatInt(inv.Int(), 10))
return true
}
case reflect.Float64:
if outt == typeJSONNumber {
out.SetString(strconv.FormatFloat(inv.Float(), 'f', -1, 64))
return true
}
}
case reflect.Slice, reflect.Array:
// Remember, array (0x04) slices are built with the correct
// element type. If we are here, must be a cross BSON kind
// conversion (e.g. 0x05 unmarshalling on string).
if outt.Elem().Kind() != reflect.Uint8 {
break
}
switch inv.Kind() {
case reflect.String:
slice := []byte(inv.String())
out.Set(reflect.ValueOf(slice))
return true
case reflect.Slice:
switch outt.Kind() {
case reflect.Array:
reflect.Copy(out, inv)
case reflect.Slice:
out.SetBytes(inv.Bytes())
}
return true
}
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
switch inv.Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
out.SetInt(inv.Int())
return true
case reflect.Float32, reflect.Float64:
out.SetInt(int64(inv.Float()))
return true
case reflect.Bool:
if inv.Bool() {
out.SetInt(1)
} else {
out.SetInt(0)
}
return true
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
panic("can't happen: no uint types in BSON (!?)")
}
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
switch inv.Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
out.SetUint(uint64(inv.Int()))
return true
case reflect.Float32, reflect.Float64:
out.SetUint(uint64(inv.Float()))
return true
case reflect.Bool:
if inv.Bool() {
out.SetUint(1)
} else {
out.SetUint(0)
}
return true
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
panic("Can't happen. No uint types in BSON.")
}
case reflect.Float32, reflect.Float64:
switch inv.Kind() {
case reflect.Float32, reflect.Float64:
out.SetFloat(inv.Float())
return true
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
out.SetFloat(float64(inv.Int()))
return true
case reflect.Bool:
if inv.Bool() {
out.SetFloat(1)
} else {
out.SetFloat(0)
}
return true
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
panic("Can't happen. No uint types in BSON?")
}
case reflect.Bool:
switch inv.Kind() {
case reflect.Bool:
out.SetBool(inv.Bool())
return true
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
out.SetBool(inv.Int() != 0)
return true
case reflect.Float32, reflect.Float64:
out.SetBool(inv.Float() != 0)
return true
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
panic("Can't happen. No uint types in BSON?")
}
case reflect.Struct:
if outt == typeURL && inv.Kind() == reflect.String {
u, err := url.Parse(inv.String())
if err != nil {
panic(err)
}
out.Set(reflect.ValueOf(u).Elem())
return true
}
if outt == typeBinary {
if b, ok := in.([]byte); ok {
out.Set(reflect.ValueOf(Binary{Data: b}))
return true
}
}
}
return false
}
// --------------------------------------------------------------------------
// Parsers of basic types.
func (d *decoder) readRegEx() RegEx {
re := RegEx{}
re.Pattern = d.readCStr()
re.Options = d.readCStr()
return re
}
func (d *decoder) readBinary() Binary {
l := d.readInt32()
b := Binary{}
b.Kind = d.readByte()
b.Data = d.readBytes(l)
if b.Kind == 0x02 && len(b.Data) >= 4 {
// Weird obsolete format with redundant length.
b.Data = b.Data[4:]
}
return b
}
func (d *decoder) readStr() string {
l := d.readInt32()
b := d.readBytes(l - 1)
if d.readByte() != '\x00' {
corrupted()
}
return string(b)
}
func (d *decoder) readCStr() string {
start := d.i
end := start
l := len(d.in)
for ; end != l; end++ {
if d.in[end] == '\x00' {
break
}
}
d.i = end + 1
if d.i > l {
corrupted()
}
return string(d.in[start:end])
}
func (d *decoder) readBool() bool {
b := d.readByte()
if b == 0 {
return false
}
if b == 1 {
return true
}
panic(fmt.Sprintf("encoded boolean must be 1 or 0, found %d", b))
}
func (d *decoder) readFloat64() float64 {
return math.Float64frombits(uint64(d.readInt64()))
}
func (d *decoder) readInt32() int32 {
b := d.readBytes(4)
return int32((uint32(b[0]) << 0) |
(uint32(b[1]) << 8) |
(uint32(b[2]) << 16) |
(uint32(b[3]) << 24))
}
func (d *decoder) readInt64() int64 {
b := d.readBytes(8)
return int64((uint64(b[0]) << 0) |
(uint64(b[1]) << 8) |
(uint64(b[2]) << 16) |
(uint64(b[3]) << 24) |
(uint64(b[4]) << 32) |
(uint64(b[5]) << 40) |
(uint64(b[6]) << 48) |
(uint64(b[7]) << 56))
}
func (d *decoder) readByte() byte {
i := d.i
d.i++
if d.i > len(d.in) {
corrupted()
}
return d.in[i]
}
func (d *decoder) readBytes(length int32) []byte {
if length < 0 {
corrupted()
}
start := d.i
d.i += int(length)
if d.i < start || d.i > len(d.in) {
corrupted()
}
return d.in[start : start+int(length)]
}