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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 (
"encoding/json"
"fmt"
"math"
"net/url"
"reflect"
"strconv"
"time"
)
// --------------------------------------------------------------------------
// Some internal infrastructure.
var (
typeBinary = reflect.TypeOf(Binary{})
typeObjectId = reflect.TypeOf(ObjectId(""))
typeDBPointer = reflect.TypeOf(DBPointer{"", ObjectId("")})
typeSymbol = reflect.TypeOf(Symbol(""))
typeMongoTimestamp = reflect.TypeOf(MongoTimestamp(0))
typeOrderKey = reflect.TypeOf(MinKey)
typeDocElem = reflect.TypeOf(DocElem{})
typeRawDocElem = reflect.TypeOf(RawDocElem{})
typeRaw = reflect.TypeOf(Raw{})
typeURL = reflect.TypeOf(url.URL{})
typeTime = reflect.TypeOf(time.Time{})
typeString = reflect.TypeOf("")
typeJSONNumber = reflect.TypeOf(json.Number(""))
)
const itoaCacheSize = 32
var itoaCache []string
func init() {
itoaCache = make([]string, itoaCacheSize)
for i := 0; i != itoaCacheSize; i++ {
itoaCache[i] = strconv.Itoa(i)
}
}
func itoa(i int) string {
if i < itoaCacheSize {
return itoaCache[i]
}
return strconv.Itoa(i)
}
// --------------------------------------------------------------------------
// Marshaling of the document value itself.
type encoder struct {
out []byte
}
func (e *encoder) addDoc(v reflect.Value) {
for {
if vi, ok := v.Interface().(Getter); ok {
getv, err := vi.GetBSON()
if err != nil {
panic(err)
}
v = reflect.ValueOf(getv)
continue
}
if v.Kind() == reflect.Ptr {
v = v.Elem()
continue
}
break
}
if v.Type() == typeRaw {
raw := v.Interface().(Raw)
if raw.Kind != 0x03 && raw.Kind != 0x00 {
panic("Attempted to marshal Raw kind " + strconv.Itoa(int(raw.Kind)) + " as a document")
}
if len(raw.Data) == 0 {
panic("Attempted to marshal empty Raw document")
}
e.addBytes(raw.Data...)
return
}
start := e.reserveInt32()
switch v.Kind() {
case reflect.Map:
e.addMap(v)
case reflect.Struct:
e.addStruct(v)
case reflect.Array, reflect.Slice:
e.addSlice(v)
default:
panic("Can't marshal " + v.Type().String() + " as a BSON document")
}
e.addBytes(0)
e.setInt32(start, int32(len(e.out)-start))
}
func (e *encoder) addMap(v reflect.Value) {
for _, k := range v.MapKeys() {
e.addElem(k.String(), v.MapIndex(k), false)
}
}
func (e *encoder) addStruct(v reflect.Value) {
sinfo, err := getStructInfo(v.Type())
if err != nil {
panic(err)
}
var value reflect.Value
if sinfo.InlineMap >= 0 {
m := v.Field(sinfo.InlineMap)
if m.Len() > 0 {
for _, k := range m.MapKeys() {
ks := k.String()
if _, found := sinfo.FieldsMap[ks]; found {
panic(fmt.Sprintf("Can't have key %q in inlined map; conflicts with struct field", ks))
}
e.addElem(ks, m.MapIndex(k), false)
}
}
}
for _, info := range sinfo.FieldsList {
if info.Inline == nil {
value = v.Field(info.Num)
} else {
value = v.FieldByIndex(info.Inline)
}
if info.OmitEmpty && isZero(value) {
continue
}
e.addElem(info.Key, value, info.MinSize)
}
}
func isZero(v reflect.Value) bool {
switch v.Kind() {
case reflect.String:
return len(v.String()) == 0
case reflect.Ptr, reflect.Interface:
return v.IsNil()
case reflect.Slice:
return v.Len() == 0
case reflect.Map:
return v.Len() == 0
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
return v.Int() == 0
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
return v.Uint() == 0
case reflect.Float32, reflect.Float64:
return v.Float() == 0
case reflect.Bool:
return !v.Bool()
case reflect.Struct:
vt := v.Type()
if vt == typeTime {
return v.Interface().(time.Time).IsZero()
}
for i := 0; i < v.NumField(); i++ {
if vt.Field(i).PkgPath != "" {
continue // Private field
}
if !isZero(v.Field(i)) {
return false
}
}
return true
}
return false
}
func (e *encoder) addSlice(v reflect.Value) {
vi := v.Interface()
if d, ok := vi.(D); ok {
for _, elem := range d {
e.addElem(elem.Name, reflect.ValueOf(elem.Value), false)
}
return
}
if d, ok := vi.(RawD); ok {
for _, elem := range d {
e.addElem(elem.Name, reflect.ValueOf(elem.Value), false)
}
return
}
l := v.Len()
et := v.Type().Elem()
if et == typeDocElem {
for i := 0; i < l; i++ {
elem := v.Index(i).Interface().(DocElem)
e.addElem(elem.Name, reflect.ValueOf(elem.Value), false)
}
return
}
if et == typeRawDocElem {
for i := 0; i < l; i++ {
elem := v.Index(i).Interface().(RawDocElem)
e.addElem(elem.Name, reflect.ValueOf(elem.Value), false)
}
return
}
for i := 0; i < l; i++ {
e.addElem(itoa(i), v.Index(i), false)
}
}
// --------------------------------------------------------------------------
// Marshaling of elements in a document.
func (e *encoder) addElemName(kind byte, name string) {
e.addBytes(kind)
e.addBytes([]byte(name)...)
e.addBytes(0)
}
func (e *encoder) addElem(name string, v reflect.Value, minSize bool) {
if !v.IsValid() {
e.addElemName('\x0A', name)
return
}
if getter, ok := v.Interface().(Getter); ok {
getv, err := getter.GetBSON()
if err != nil {
panic(err)
}
e.addElem(name, reflect.ValueOf(getv), minSize)
return
}
switch v.Kind() {
case reflect.Interface:
e.addElem(name, v.Elem(), minSize)
case reflect.Ptr:
e.addElem(name, v.Elem(), minSize)
case reflect.String:
s := v.String()
switch v.Type() {
case typeObjectId:
if len(s) != 12 {
panic("ObjectIDs must be exactly 12 bytes long (got " +
strconv.Itoa(len(s)) + ")")
}
e.addElemName('\x07', name)
e.addBytes([]byte(s)...)
case typeSymbol:
e.addElemName('\x0E', name)
e.addStr(s)
case typeJSONNumber:
n := v.Interface().(json.Number)
if i, err := n.Int64(); err == nil {
e.addElemName('\x12', name)
e.addInt64(i)
} else if f, err := n.Float64(); err == nil {
e.addElemName('\x01', name)
e.addFloat64(f)
} else {
panic("failed to convert json.Number to a number: " + s)
}
default:
e.addElemName('\x02', name)
e.addStr(s)
}
case reflect.Float32, reflect.Float64:
e.addElemName('\x01', name)
e.addFloat64(v.Float())
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
u := v.Uint()
if int64(u) < 0 {
panic("BSON has no uint64 type, and value is too large to fit correctly in an int64")
} else if u <= math.MaxInt32 && (minSize || v.Kind() <= reflect.Uint32) {
e.addElemName('\x10', name)
e.addInt32(int32(u))
} else {
e.addElemName('\x12', name)
e.addInt64(int64(u))
}
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
switch v.Type() {
case typeMongoTimestamp:
e.addElemName('\x11', name)
e.addInt64(v.Int())
case typeOrderKey:
if v.Int() == int64(MaxKey) {
e.addElemName('\x7F', name)
} else {
e.addElemName('\xFF', name)
}
default:
i := v.Int()
if (minSize || v.Type().Kind() != reflect.Int64) && i >= math.MinInt32 && i <= math.MaxInt32 {
// It fits into an int32, encode as such.
e.addElemName('\x10', name)
e.addInt32(int32(i))
} else {
e.addElemName('\x12', name)
e.addInt64(i)
}
}
case reflect.Bool:
e.addElemName('\x08', name)
if v.Bool() {
e.addBytes(1)
} else {
e.addBytes(0)
}
case reflect.Map:
e.addElemName('\x03', name)
e.addDoc(v)
case reflect.Slice:
vt := v.Type()
et := vt.Elem()
if et.Kind() == reflect.Uint8 {
e.addElemName('\x05', name)
e.addBinary('\x00', v.Bytes())
} else if et == typeDocElem || et == typeRawDocElem {
e.addElemName('\x03', name)
e.addDoc(v)
} else {
e.addElemName('\x04', name)
e.addDoc(v)
}
case reflect.Array:
et := v.Type().Elem()
if et.Kind() == reflect.Uint8 {
e.addElemName('\x05', name)
if v.CanAddr() {
e.addBinary('\x00', v.Slice(0, v.Len()).Interface().([]byte))
} else {
n := v.Len()
e.addInt32(int32(n))
e.addBytes('\x00')
for i := 0; i < n; i++ {
el := v.Index(i)
e.addBytes(byte(el.Uint()))
}
}
} else {
e.addElemName('\x04', name)
e.addDoc(v)
}
case reflect.Struct:
switch s := v.Interface().(type) {
case Raw:
kind := s.Kind
if kind == 0x00 {
kind = 0x03
}
if len(s.Data) == 0 && kind != 0x06 && kind != 0x0A && kind != 0xFF && kind != 0x7F {
panic("Attempted to marshal empty Raw document")
}
e.addElemName(kind, name)
e.addBytes(s.Data...)
case Binary:
e.addElemName('\x05', name)
e.addBinary(s.Kind, s.Data)
case DBPointer:
e.addElemName('\x0C', name)
e.addStr(s.Namespace)
if len(s.Id) != 12 {
panic("ObjectIDs must be exactly 12 bytes long (got " +
strconv.Itoa(len(s.Id)) + ")")
}
e.addBytes([]byte(s.Id)...)
case RegEx:
e.addElemName('\x0B', name)
e.addCStr(s.Pattern)
e.addCStr(s.Options)
case JavaScript:
if s.Scope == nil {
e.addElemName('\x0D', name)
e.addStr(s.Code)
} else {
e.addElemName('\x0F', name)
start := e.reserveInt32()
e.addStr(s.Code)
e.addDoc(reflect.ValueOf(s.Scope))
e.setInt32(start, int32(len(e.out)-start))
}
case time.Time:
// MongoDB handles timestamps as milliseconds.
e.addElemName('\x09', name)
e.addInt64(s.Unix()*1000 + int64(s.Nanosecond()/1e6))
case url.URL:
e.addElemName('\x02', name)
e.addStr(s.String())
case undefined:
e.addElemName('\x06', name)
default:
e.addElemName('\x03', name)
e.addDoc(v)
}
default:
panic("Can't marshal " + v.Type().String() + " in a BSON document")
}
}
// --------------------------------------------------------------------------
// Marshaling of base types.
func (e *encoder) addBinary(subtype byte, v []byte) {
if subtype == 0x02 {
// Wonder how that brilliant idea came to life. Obsolete, luckily.
e.addInt32(int32(len(v) + 4))
e.addBytes(subtype)
e.addInt32(int32(len(v)))
} else {
e.addInt32(int32(len(v)))
e.addBytes(subtype)
}
e.addBytes(v...)
}
func (e *encoder) addStr(v string) {
e.addInt32(int32(len(v) + 1))
e.addCStr(v)
}
func (e *encoder) addCStr(v string) {
e.addBytes([]byte(v)...)
e.addBytes(0)
}
func (e *encoder) reserveInt32() (pos int) {
pos = len(e.out)
e.addBytes(0, 0, 0, 0)
return pos
}
func (e *encoder) setInt32(pos int, v int32) {
e.out[pos+0] = byte(v)
e.out[pos+1] = byte(v >> 8)
e.out[pos+2] = byte(v >> 16)
e.out[pos+3] = byte(v >> 24)
}
func (e *encoder) addInt32(v int32) {
u := uint32(v)
e.addBytes(byte(u), byte(u>>8), byte(u>>16), byte(u>>24))
}
func (e *encoder) addInt64(v int64) {
u := uint64(v)
e.addBytes(byte(u), byte(u>>8), byte(u>>16), byte(u>>24),
byte(u>>32), byte(u>>40), byte(u>>48), byte(u>>56))
}
func (e *encoder) addFloat64(v float64) {
e.addInt64(int64(math.Float64bits(v)))
}
func (e *encoder) addBytes(v ...byte) {
e.out = append(e.out, v...)
}