diff --git a/vendor.conf b/vendor.conf
index 3aa99ee0c..62a4e70ed 100644
--- a/vendor.conf
+++ b/vendor.conf
@@ -32,6 +32,7 @@ github.com/gregjones/httpcache 787624de3eb7bd915c329cba748687a3b22666a6
 github.com/hashicorp/errwrap 7554cd9344cec97297fa6649b055a8c98c2a1e55
 github.com/hashicorp/go-multierror ed905158d87462226a13fe39ddf685ea65f1c11f
 github.com/inconshreveable/mousetrap 76626ae9c91c4f2a10f34cad8ce83ea42c93bb75
+github.com/json-iterator/go 13f86432b882000a51c6e610c620974462691a97
 github.com/juju/ratelimit 5b9ff866471762aa2ab2dced63c9fb6f53921342
 github.com/mailru/easyjson d5b7844b561a7bc640052f1b935f7b800330d7e0
 github.com/Microsoft/go-winio v0.4.4
diff --git a/vendor/github.com/json-iterator/go/README.md b/vendor/github.com/json-iterator/go/README.md
index 23a4b57c8..3a0d68098 100644
--- a/vendor/github.com/json-iterator/go/README.md
+++ b/vendor/github.com/json-iterator/go/README.md
@@ -44,7 +44,9 @@ with
 
 ```go
 import "github.com/json-iterator/go"
-jsoniter.Marshal(&data)
+
+var json = jsoniter.ConfigCompatibleWithStandardLibrary
+json.Marshal(&data)
 ```
 
 Replace
@@ -58,7 +60,9 @@ with
 
 ```go
 import "github.com/json-iterator/go"
-jsoniter.Unmarshal(input, &data)
+
+var json = jsoniter.ConfigCompatibleWithStandardLibrary
+json.Unmarshal(input, &data)
 ```
 
 [More documentation](http://jsoniter.com/migrate-from-go-std.html)
@@ -76,5 +80,7 @@ Contributors
 * [thockin](https://github.com/thockin) 
 * [mattn](https://github.com/mattn)
 * [cch123](https://github.com/cch123)
+* [Oleg Shaldybin](https://github.com/olegshaldybin)
+* [Jason Toffaletti](https://github.com/toffaletti)
 
 Report issue or pull request, or email taowen@gmail.com, or [![Gitter chat](https://badges.gitter.im/gitterHQ/gitter.png)](https://gitter.im/json-iterator/Lobby)
diff --git a/vendor/github.com/json-iterator/go/feature_adapter.go b/vendor/github.com/json-iterator/go/feature_adapter.go
index edb477c4f..0214b711a 100644
--- a/vendor/github.com/json-iterator/go/feature_adapter.go
+++ b/vendor/github.com/json-iterator/go/feature_adapter.go
@@ -110,6 +110,7 @@ type Encoder struct {
 // Encode encode interface{} as JSON to io.Writer
 func (adapter *Encoder) Encode(val interface{}) error {
 	adapter.stream.WriteVal(val)
+	adapter.stream.WriteRaw("\n")
 	adapter.stream.Flush()
 	return adapter.stream.Error
 }
@@ -125,3 +126,8 @@ func (adapter *Encoder) SetEscapeHTML(escapeHTML bool) {
 	config.EscapeHTML = escapeHTML
 	adapter.stream.cfg = config.Froze().(*frozenConfig)
 }
+
+// Valid reports whether data is a valid JSON encoding.
+func Valid(data []byte) bool {
+	return ConfigDefault.Valid(data)
+}
diff --git a/vendor/github.com/json-iterator/go/feature_any.go b/vendor/github.com/json-iterator/go/feature_any.go
index 6733dce4c..87716d1fc 100644
--- a/vendor/github.com/json-iterator/go/feature_any.go
+++ b/vendor/github.com/json-iterator/go/feature_any.go
@@ -1,6 +1,7 @@
 package jsoniter
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"reflect"
@@ -157,6 +158,8 @@ func (iter *Iterator) readAny() Any {
 		return iter.readArrayAny()
 	case '-':
 		return iter.readNumberAny(false)
+	case 0:
+		return &invalidAny{baseAny{}, errors.New("input is empty")}
 	default:
 		return iter.readNumberAny(true)
 	}
diff --git a/vendor/github.com/json-iterator/go/feature_config.go b/vendor/github.com/json-iterator/go/feature_config.go
index fc055d504..78a2ce1a5 100644
--- a/vendor/github.com/json-iterator/go/feature_config.go
+++ b/vendor/github.com/json-iterator/go/feature_config.go
@@ -12,23 +12,26 @@ import (
 // Config customize how the API should behave.
 // The API is created from Config by Froze.
 type Config struct {
-	IndentionStep           int
-	MarshalFloatWith6Digits bool
-	EscapeHTML              bool
-	SortMapKeys             bool
-	UseNumber               bool
-	TagKey                  string
+	IndentionStep                 int
+	MarshalFloatWith6Digits       bool
+	EscapeHTML                    bool
+	SortMapKeys                   bool
+	UseNumber                     bool
+	TagKey                        string
+	ValidateJsonRawMessage        bool
+	ObjectFieldMustBeSimpleString bool
 }
 
 type frozenConfig struct {
-	configBeforeFrozen Config
-	sortMapKeys        bool
-	indentionStep      int
-	decoderCache       unsafe.Pointer
-	encoderCache       unsafe.Pointer
-	extensions         []Extension
-	streamPool         chan *Stream
-	iteratorPool       chan *Iterator
+	configBeforeFrozen            Config
+	sortMapKeys                   bool
+	indentionStep                 int
+	objectFieldMustBeSimpleString bool
+	decoderCache                  unsafe.Pointer
+	encoderCache                  unsafe.Pointer
+	extensions                    []Extension
+	streamPool                    chan *Stream
+	iteratorPool                  chan *Iterator
 }
 
 // API the public interface of this package.
@@ -44,6 +47,8 @@ type API interface {
 	Get(data []byte, path ...interface{}) Any
 	NewEncoder(writer io.Writer) *Encoder
 	NewDecoder(reader io.Reader) *Decoder
+	Valid(data []byte) bool
+	RegisterExtension(extension Extension)
 }
 
 // ConfigDefault the default API
@@ -53,24 +58,27 @@ var ConfigDefault = Config{
 
 // ConfigCompatibleWithStandardLibrary tries to be 100% compatible with standard library behavior
 var ConfigCompatibleWithStandardLibrary = Config{
-	EscapeHTML:  true,
-	SortMapKeys: true,
+	EscapeHTML:             true,
+	SortMapKeys:            true,
+	ValidateJsonRawMessage: true,
 }.Froze()
 
 // ConfigFastest marshals float with only 6 digits precision
 var ConfigFastest = Config{
-	EscapeHTML:              false,
-	MarshalFloatWith6Digits: true,
+	EscapeHTML:                    false,
+	MarshalFloatWith6Digits:       true, // will lose precession
+	ObjectFieldMustBeSimpleString: true, // do not unescape object field
 }.Froze()
 
 // Froze forge API from config
 func (cfg Config) Froze() API {
 	// TODO: cache frozen config
 	frozenConfig := &frozenConfig{
-		sortMapKeys:   cfg.SortMapKeys,
-		indentionStep: cfg.IndentionStep,
-		streamPool:    make(chan *Stream, 16),
-		iteratorPool:  make(chan *Iterator, 16),
+		sortMapKeys:                   cfg.SortMapKeys,
+		indentionStep:                 cfg.IndentionStep,
+		objectFieldMustBeSimpleString: cfg.ObjectFieldMustBeSimpleString,
+		streamPool:                    make(chan *Stream, 16),
+		iteratorPool:                  make(chan *Iterator, 16),
 	}
 	atomic.StorePointer(&frozenConfig.decoderCache, unsafe.Pointer(&map[string]ValDecoder{}))
 	atomic.StorePointer(&frozenConfig.encoderCache, unsafe.Pointer(&map[string]ValEncoder{}))
@@ -83,10 +91,31 @@ func (cfg Config) Froze() API {
 	if cfg.UseNumber {
 		frozenConfig.useNumber()
 	}
+	if cfg.ValidateJsonRawMessage {
+		frozenConfig.validateJsonRawMessage()
+	}
 	frozenConfig.configBeforeFrozen = cfg
 	return frozenConfig
 }
 
+func (cfg *frozenConfig) validateJsonRawMessage() {
+	encoder := &funcEncoder{func(ptr unsafe.Pointer, stream *Stream) {
+		rawMessage := *(*json.RawMessage)(ptr)
+		iter := cfg.BorrowIterator([]byte(rawMessage))
+		iter.Read()
+		if iter.Error != nil {
+			stream.WriteRaw("null")
+		} else {
+			cfg.ReturnIterator(iter)
+			stream.WriteRaw(string(rawMessage))
+		}
+	}, func(ptr unsafe.Pointer) bool {
+		return false
+	}}
+	cfg.addEncoderToCache(reflect.TypeOf((*json.RawMessage)(nil)).Elem(), encoder)
+	cfg.addEncoderToCache(reflect.TypeOf((*RawMessage)(nil)).Elem(), encoder)
+}
+
 func (cfg *frozenConfig) useNumber() {
 	cfg.addDecoderToCache(reflect.TypeOf((*interface{})(nil)).Elem(), &funcDecoder{func(ptr unsafe.Pointer, iter *Iterator) {
 		if iter.WhatIsNext() == NumberValue {
@@ -104,7 +133,7 @@ func (cfg *frozenConfig) getTagKey() string {
 	return tagKey
 }
 
-func (cfg *frozenConfig) registerExtension(extension Extension) {
+func (cfg *frozenConfig) RegisterExtension(extension Extension) {
 	cfg.extensions = append(cfg.extensions, extension)
 }
 
@@ -310,3 +339,10 @@ func (cfg *frozenConfig) NewDecoder(reader io.Reader) *Decoder {
 	iter := Parse(cfg, reader, 512)
 	return &Decoder{iter}
 }
+
+func (cfg *frozenConfig) Valid(data []byte) bool {
+	iter := cfg.BorrowIterator(data)
+	defer cfg.ReturnIterator(iter)
+	iter.Skip()
+	return iter.Error == nil
+}
diff --git a/vendor/github.com/json-iterator/go/feature_iter.go b/vendor/github.com/json-iterator/go/feature_iter.go
index 4357d69ba..95ae54fbf 100644
--- a/vendor/github.com/json-iterator/go/feature_iter.go
+++ b/vendor/github.com/json-iterator/go/feature_iter.go
@@ -77,6 +77,7 @@ type Iterator struct {
 	captureStartedAt int
 	captured         []byte
 	Error            error
+	Attachment       interface{} // open for customized decoder
 }
 
 // NewIterator creates an empty Iterator instance
@@ -167,7 +168,7 @@ func (iter *Iterator) isObjectEnd() bool {
 	if c == '}' {
 		return true
 	}
-	iter.ReportError("isObjectEnd", "object ended prematurely")
+	iter.ReportError("isObjectEnd", "object ended prematurely, unexpected char "+string([]byte{c}))
 	return true
 }
 
@@ -200,8 +201,22 @@ func (iter *Iterator) ReportError(operation string, msg string) {
 	if peekStart < 0 {
 		peekStart = 0
 	}
-	iter.Error = fmt.Errorf("%s: %s, parsing %v ...%s... at %s", operation, msg, iter.head,
-		string(iter.buf[peekStart:iter.head]), string(iter.buf[0:iter.tail]))
+	peekEnd := iter.head + 10
+	if peekEnd > iter.tail {
+		peekEnd = iter.tail
+	}
+	parsing := string(iter.buf[peekStart:peekEnd])
+	contextStart := iter.head - 50
+	if contextStart < 0 {
+		contextStart = 0
+	}
+	contextEnd := iter.head + 50
+	if contextEnd > iter.tail {
+		contextEnd = iter.tail
+	}
+	context := string(iter.buf[contextStart:contextEnd])
+	iter.Error = fmt.Errorf("%s: %s, error found in #%v byte of ...|%s|..., bigger context ...|%s|...",
+		operation, msg, iter.head-peekStart, parsing, context)
 }
 
 // CurrentBuffer gets current buffer as string for debugging purpose
@@ -210,7 +225,7 @@ func (iter *Iterator) CurrentBuffer() string {
 	if peekStart < 0 {
 		peekStart = 0
 	}
-	return fmt.Sprintf("parsing %v ...|%s|... at %s", iter.head,
+	return fmt.Sprintf("parsing #%v byte, around ...|%s|..., whole buffer ...|%s|...", iter.head,
 		string(iter.buf[peekStart:iter.head]), string(iter.buf[0:iter.tail]))
 }
 
diff --git a/vendor/github.com/json-iterator/go/feature_iter_array.go b/vendor/github.com/json-iterator/go/feature_iter_array.go
index cbc3ec8d1..6188cb457 100644
--- a/vendor/github.com/json-iterator/go/feature_iter_array.go
+++ b/vendor/github.com/json-iterator/go/feature_iter_array.go
@@ -19,7 +19,7 @@ func (iter *Iterator) ReadArray() (ret bool) {
 	case ',':
 		return true
 	default:
-		iter.ReportError("ReadArray", "expect [ or , or ] or n, but found: "+string([]byte{c}))
+		iter.ReportError("ReadArray", "expect [ or , or ] or n, but found "+string([]byte{c}))
 		return
 	}
 }
@@ -42,7 +42,7 @@ func (iter *Iterator) ReadArrayCB(callback func(*Iterator) bool) (ret bool) {
 				c = iter.nextToken()
 			}
 			if c != ']' {
-				iter.ReportError("ReadArrayCB", "expect ] in the end")
+				iter.ReportError("ReadArrayCB", "expect ] in the end, but found "+string([]byte{c}))
 				return false
 			}
 			return true
@@ -53,6 +53,6 @@ func (iter *Iterator) ReadArrayCB(callback func(*Iterator) bool) (ret bool) {
 		iter.skipThreeBytes('u', 'l', 'l')
 		return true // null
 	}
-	iter.ReportError("ReadArrayCB", "expect [ or n, but found: "+string([]byte{c}))
+	iter.ReportError("ReadArrayCB", "expect [ or n, but found "+string([]byte{c}))
 	return false
 }
diff --git a/vendor/github.com/json-iterator/go/feature_iter_int.go b/vendor/github.com/json-iterator/go/feature_iter_int.go
index 886879efd..4781c6393 100644
--- a/vendor/github.com/json-iterator/go/feature_iter_int.go
+++ b/vendor/github.com/json-iterator/go/feature_iter_int.go
@@ -115,6 +115,7 @@ func (iter *Iterator) ReadUint32() (ret uint32) {
 func (iter *Iterator) readUint32(c byte) (ret uint32) {
 	ind := intDigits[c]
 	if ind == 0 {
+		iter.assertInteger()
 		return 0 // single zero
 	}
 	if ind == invalidCharForNumber {
@@ -127,12 +128,14 @@ func (iter *Iterator) readUint32(c byte) (ret uint32) {
 		ind2 := intDigits[iter.buf[i]]
 		if ind2 == invalidCharForNumber {
 			iter.head = i
+			iter.assertInteger()
 			return value
 		}
 		i++
 		ind3 := intDigits[iter.buf[i]]
 		if ind3 == invalidCharForNumber {
 			iter.head = i
+			iter.assertInteger()
 			return value*10 + uint32(ind2)
 		}
 		//iter.head = i + 1
@@ -141,30 +144,35 @@ func (iter *Iterator) readUint32(c byte) (ret uint32) {
 		ind4 := intDigits[iter.buf[i]]
 		if ind4 == invalidCharForNumber {
 			iter.head = i
+			iter.assertInteger()
 			return value*100 + uint32(ind2)*10 + uint32(ind3)
 		}
 		i++
 		ind5 := intDigits[iter.buf[i]]
 		if ind5 == invalidCharForNumber {
 			iter.head = i
+			iter.assertInteger()
 			return value*1000 + uint32(ind2)*100 + uint32(ind3)*10 + uint32(ind4)
 		}
 		i++
 		ind6 := intDigits[iter.buf[i]]
 		if ind6 == invalidCharForNumber {
 			iter.head = i
+			iter.assertInteger()
 			return value*10000 + uint32(ind2)*1000 + uint32(ind3)*100 + uint32(ind4)*10 + uint32(ind5)
 		}
 		i++
 		ind7 := intDigits[iter.buf[i]]
 		if ind7 == invalidCharForNumber {
 			iter.head = i
+			iter.assertInteger()
 			return value*100000 + uint32(ind2)*10000 + uint32(ind3)*1000 + uint32(ind4)*100 + uint32(ind5)*10 + uint32(ind6)
 		}
 		i++
 		ind8 := intDigits[iter.buf[i]]
 		if ind8 == invalidCharForNumber {
 			iter.head = i
+			iter.assertInteger()
 			return value*1000000 + uint32(ind2)*100000 + uint32(ind3)*10000 + uint32(ind4)*1000 + uint32(ind5)*100 + uint32(ind6)*10 + uint32(ind7)
 		}
 		i++
@@ -172,6 +180,7 @@ func (iter *Iterator) readUint32(c byte) (ret uint32) {
 		value = value*10000000 + uint32(ind2)*1000000 + uint32(ind3)*100000 + uint32(ind4)*10000 + uint32(ind5)*1000 + uint32(ind6)*100 + uint32(ind7)*10 + uint32(ind8)
 		iter.head = i
 		if ind9 == invalidCharForNumber {
+			iter.assertInteger()
 			return value
 		}
 	}
@@ -180,6 +189,7 @@ func (iter *Iterator) readUint32(c byte) (ret uint32) {
 			ind = intDigits[iter.buf[i]]
 			if ind == invalidCharForNumber {
 				iter.head = i
+				iter.assertInteger()
 				return value
 			}
 			if value > uint32SafeToMultiply10 {
@@ -194,6 +204,7 @@ func (iter *Iterator) readUint32(c byte) (ret uint32) {
 			value = (value << 3) + (value << 1) + uint32(ind)
 		}
 		if !iter.loadMore() {
+			iter.assertInteger()
 			return value
 		}
 	}
@@ -226,6 +237,7 @@ func (iter *Iterator) ReadUint64() uint64 {
 func (iter *Iterator) readUint64(c byte) (ret uint64) {
 	ind := intDigits[c]
 	if ind == 0 {
+		iter.assertInteger()
 		return 0 // single zero
 	}
 	if ind == invalidCharForNumber {
@@ -233,11 +245,73 @@ func (iter *Iterator) readUint64(c byte) (ret uint64) {
 		return
 	}
 	value := uint64(ind)
+	if iter.tail-iter.head > 10 {
+		i := iter.head
+		ind2 := intDigits[iter.buf[i]]
+		if ind2 == invalidCharForNumber {
+			iter.head = i
+			iter.assertInteger()
+			return value
+		}
+		i++
+		ind3 := intDigits[iter.buf[i]]
+		if ind3 == invalidCharForNumber {
+			iter.head = i
+			iter.assertInteger()
+			return value*10 + uint64(ind2)
+		}
+		//iter.head = i + 1
+		//value = value * 100 + uint32(ind2) * 10 + uint32(ind3)
+		i++
+		ind4 := intDigits[iter.buf[i]]
+		if ind4 == invalidCharForNumber {
+			iter.head = i
+			iter.assertInteger()
+			return value*100 + uint64(ind2)*10 + uint64(ind3)
+		}
+		i++
+		ind5 := intDigits[iter.buf[i]]
+		if ind5 == invalidCharForNumber {
+			iter.head = i
+			iter.assertInteger()
+			return value*1000 + uint64(ind2)*100 + uint64(ind3)*10 + uint64(ind4)
+		}
+		i++
+		ind6 := intDigits[iter.buf[i]]
+		if ind6 == invalidCharForNumber {
+			iter.head = i
+			iter.assertInteger()
+			return value*10000 + uint64(ind2)*1000 + uint64(ind3)*100 + uint64(ind4)*10 + uint64(ind5)
+		}
+		i++
+		ind7 := intDigits[iter.buf[i]]
+		if ind7 == invalidCharForNumber {
+			iter.head = i
+			iter.assertInteger()
+			return value*100000 + uint64(ind2)*10000 + uint64(ind3)*1000 + uint64(ind4)*100 + uint64(ind5)*10 + uint64(ind6)
+		}
+		i++
+		ind8 := intDigits[iter.buf[i]]
+		if ind8 == invalidCharForNumber {
+			iter.head = i
+			iter.assertInteger()
+			return value*1000000 + uint64(ind2)*100000 + uint64(ind3)*10000 + uint64(ind4)*1000 + uint64(ind5)*100 + uint64(ind6)*10 + uint64(ind7)
+		}
+		i++
+		ind9 := intDigits[iter.buf[i]]
+		value = value*10000000 + uint64(ind2)*1000000 + uint64(ind3)*100000 + uint64(ind4)*10000 + uint64(ind5)*1000 + uint64(ind6)*100 + uint64(ind7)*10 + uint64(ind8)
+		iter.head = i
+		if ind9 == invalidCharForNumber {
+			iter.assertInteger()
+			return value
+		}
+	}
 	for {
 		for i := iter.head; i < iter.tail; i++ {
 			ind = intDigits[iter.buf[i]]
 			if ind == invalidCharForNumber {
 				iter.head = i
+				iter.assertInteger()
 				return value
 			}
 			if value > uint64SafeToMultiple10 {
@@ -252,7 +326,14 @@ func (iter *Iterator) readUint64(c byte) (ret uint64) {
 			value = (value << 3) + (value << 1) + uint64(ind)
 		}
 		if !iter.loadMore() {
+			iter.assertInteger()
 			return value
 		}
 	}
 }
+
+func (iter *Iterator) assertInteger() {
+	if iter.head < len(iter.buf) && iter.buf[iter.head] == '.' {
+		iter.ReportError("assertInteger", "can not decode float as int")
+	}
+}
diff --git a/vendor/github.com/json-iterator/go/feature_iter_object.go b/vendor/github.com/json-iterator/go/feature_iter_object.go
index 3bdb5576e..dfd91fa60 100644
--- a/vendor/github.com/json-iterator/go/feature_iter_object.go
+++ b/vendor/github.com/json-iterator/go/feature_iter_object.go
@@ -19,15 +19,33 @@ func (iter *Iterator) ReadObject() (ret string) {
 		c = iter.nextToken()
 		if c == '"' {
 			iter.unreadByte()
-			return string(iter.readObjectFieldAsBytes())
+			if iter.cfg.objectFieldMustBeSimpleString {
+				return string(iter.readObjectFieldAsBytes())
+			} else {
+				field := iter.ReadString()
+				c = iter.nextToken()
+				if c != ':' {
+					iter.ReportError("ReadObject", "expect : after object field, but found "+string([]byte{c}))
+				}
+				return field
+			}
 		}
 		if c == '}' {
 			return "" // end of object
 		}
-		iter.ReportError("ReadObject", `expect " after {`)
+		iter.ReportError("ReadObject", `expect " after {, but found `+string([]byte{c}))
 		return
 	case ',':
-		return string(iter.readObjectFieldAsBytes())
+		if iter.cfg.objectFieldMustBeSimpleString {
+			return string(iter.readObjectFieldAsBytes())
+		} else {
+			field := iter.ReadString()
+			c = iter.nextToken()
+			if c != ':' {
+				iter.ReportError("ReadObject", "expect : after object field, but found "+string([]byte{c}))
+			}
+			return field
+		}
 	case '}':
 		return "" // end of object
 	default:
@@ -44,17 +62,34 @@ func (iter *Iterator) readFieldHash() int32 {
 			for i := iter.head; i < iter.tail; i++ {
 				// require ascii string and no escape
 				b := iter.buf[i]
-				if 'A' <= b && b <= 'Z' {
-					b += 'a' - 'A'
+				if !iter.cfg.objectFieldMustBeSimpleString && b == '\\' {
+					iter.head = i
+					for _, b := range iter.readStringSlowPath() {
+						if 'A' <= b && b <= 'Z' {
+							b += 'a' - 'A'
+						}
+						hash ^= int64(b)
+						hash *= 0x1000193
+					}
+					c = iter.nextToken()
+					if c != ':' {
+						iter.ReportError("readFieldHash", `expect :, but found `+string([]byte{c}))
+						return 0
+					}
+					return int32(hash)
 				}
 				if b == '"' {
 					iter.head = i + 1
 					c = iter.nextToken()
 					if c != ':' {
 						iter.ReportError("readFieldHash", `expect :, but found `+string([]byte{c}))
+						return 0
 					}
 					return int32(hash)
 				}
+				if 'A' <= b && b <= 'Z' {
+					b += 'a' - 'A'
+				}
 				hash ^= int64(b)
 				hash *= 0x1000193
 			}
@@ -80,18 +115,38 @@ func calcHash(str string) int32 {
 // ReadObjectCB read object with callback, the key is ascii only and field name not copied
 func (iter *Iterator) ReadObjectCB(callback func(*Iterator, string) bool) bool {
 	c := iter.nextToken()
+	var fieldBytes []byte
+	var field string
 	if c == '{' {
 		c = iter.nextToken()
 		if c == '"' {
 			iter.unreadByte()
-			field := iter.readObjectFieldAsBytes()
-			if !callback(iter, *(*string)(unsafe.Pointer(&field))) {
+			if iter.cfg.objectFieldMustBeSimpleString {
+				fieldBytes = iter.readObjectFieldAsBytes()
+				field = *(*string)(unsafe.Pointer(&fieldBytes))
+			} else {
+				field = iter.ReadString()
+				c = iter.nextToken()
+				if c != ':' {
+					iter.ReportError("ReadObject", "expect : after object field, but found "+string([]byte{c}))
+				}
+			}
+			if !callback(iter, field) {
 				return false
 			}
 			c = iter.nextToken()
 			for c == ',' {
-				field = iter.readObjectFieldAsBytes()
-				if !callback(iter, *(*string)(unsafe.Pointer(&field))) {
+				if iter.cfg.objectFieldMustBeSimpleString {
+					fieldBytes = iter.readObjectFieldAsBytes()
+					field = *(*string)(unsafe.Pointer(&fieldBytes))
+				} else {
+					field = iter.ReadString()
+					c = iter.nextToken()
+					if c != ':' {
+						iter.ReportError("ReadObject", "expect : after object field, but found "+string([]byte{c}))
+					}
+				}
+				if !callback(iter, field) {
 					return false
 				}
 				c = iter.nextToken()
@@ -105,14 +160,14 @@ func (iter *Iterator) ReadObjectCB(callback func(*Iterator, string) bool) bool {
 		if c == '}' {
 			return true
 		}
-		iter.ReportError("ReadObjectCB", `expect " after }`)
+		iter.ReportError("ReadObjectCB", `expect " after }, but found `+string([]byte{c}))
 		return false
 	}
 	if c == 'n' {
 		iter.skipThreeBytes('u', 'l', 'l')
 		return true // null
 	}
-	iter.ReportError("ReadObjectCB", `expect { or n`)
+	iter.ReportError("ReadObjectCB", `expect { or n, but found `+string([]byte{c}))
 	return false
 }
 
@@ -125,7 +180,7 @@ func (iter *Iterator) ReadMapCB(callback func(*Iterator, string) bool) bool {
 			iter.unreadByte()
 			field := iter.ReadString()
 			if iter.nextToken() != ':' {
-				iter.ReportError("ReadMapCB", "expect : after object field")
+				iter.ReportError("ReadMapCB", "expect : after object field, but found "+string([]byte{c}))
 				return false
 			}
 			if !callback(iter, field) {
@@ -135,7 +190,7 @@ func (iter *Iterator) ReadMapCB(callback func(*Iterator, string) bool) bool {
 			for c == ',' {
 				field = iter.ReadString()
 				if iter.nextToken() != ':' {
-					iter.ReportError("ReadMapCB", "expect : after object field")
+					iter.ReportError("ReadMapCB", "expect : after object field, but found "+string([]byte{c}))
 					return false
 				}
 				if !callback(iter, field) {
@@ -152,14 +207,14 @@ func (iter *Iterator) ReadMapCB(callback func(*Iterator, string) bool) bool {
 		if c == '}' {
 			return true
 		}
-		iter.ReportError("ReadMapCB", `expect " after }`)
+		iter.ReportError("ReadMapCB", `expect " after }, but found `+string([]byte{c}))
 		return false
 	}
 	if c == 'n' {
 		iter.skipThreeBytes('u', 'l', 'l')
 		return true // null
 	}
-	iter.ReportError("ReadMapCB", `expect { or n`)
+	iter.ReportError("ReadMapCB", `expect { or n, but found `+string([]byte{c}))
 	return false
 }
 
@@ -176,7 +231,7 @@ func (iter *Iterator) readObjectStart() bool {
 		iter.skipThreeBytes('u', 'l', 'l')
 		return false
 	}
-	iter.ReportError("readObjectStart", "expect { or n")
+	iter.ReportError("readObjectStart", "expect { or n, but found "+string([]byte{c}))
 	return false
 }
 
@@ -192,7 +247,7 @@ func (iter *Iterator) readObjectFieldAsBytes() (ret []byte) {
 		}
 	}
 	if iter.buf[iter.head] != ':' {
-		iter.ReportError("readObjectFieldAsBytes", "expect : after object field")
+		iter.ReportError("readObjectFieldAsBytes", "expect : after object field, but found "+string([]byte{iter.buf[iter.head]}))
 		return
 	}
 	iter.head++
diff --git a/vendor/github.com/json-iterator/go/feature_iter_skip.go b/vendor/github.com/json-iterator/go/feature_iter_skip.go
index b008d98c9..f58beb913 100644
--- a/vendor/github.com/json-iterator/go/feature_iter_skip.go
+++ b/vendor/github.com/json-iterator/go/feature_iter_skip.go
@@ -25,7 +25,7 @@ func (iter *Iterator) ReadBool() (ret bool) {
 		iter.skipFourBytes('a', 'l', 's', 'e')
 		return false
 	}
-	iter.ReportError("ReadBool", "expect t or f")
+	iter.ReportError("ReadBool", "expect t or f, but found "+string([]byte{c}))
 	return
 }
 
@@ -59,7 +59,9 @@ func (iter *Iterator) stopCapture() []byte {
 	iter.captureStartedAt = -1
 	iter.captured = nil
 	if len(captured) == 0 {
-		return remaining
+		copied := make([]byte, len(remaining))
+		copy(copied, remaining)
+		return copied
 	}
 	captured = append(captured, remaining...)
 	return captured
diff --git a/vendor/github.com/json-iterator/go/feature_iter_skip_sloppy.go b/vendor/github.com/json-iterator/go/feature_iter_skip_sloppy.go
index 047d58a4b..8fcdc3b69 100644
--- a/vendor/github.com/json-iterator/go/feature_iter_skip_sloppy.go
+++ b/vendor/github.com/json-iterator/go/feature_iter_skip_sloppy.go
@@ -1,4 +1,4 @@
-//+build jsoniter-sloppy
+//+build jsoniter_sloppy
 
 package jsoniter
 
diff --git a/vendor/github.com/json-iterator/go/feature_iter_skip_strict.go b/vendor/github.com/json-iterator/go/feature_iter_skip_strict.go
index d26763825..f67bc2e83 100644
--- a/vendor/github.com/json-iterator/go/feature_iter_skip_strict.go
+++ b/vendor/github.com/json-iterator/go/feature_iter_skip_strict.go
@@ -1,4 +1,4 @@
-//+build !jsoniter-sloppy
+//+build !jsoniter_sloppy
 
 package jsoniter
 
@@ -64,7 +64,7 @@ func (iter *Iterator) trySkipString() bool {
 		} else if c == '\\' {
 			return false
 		} else if c < ' ' {
-			iter.ReportError("ReadString",
+			iter.ReportError("trySkipString",
 				fmt.Sprintf(`invalid control character found: %d`, c))
 			return true // already failed
 		}
diff --git a/vendor/github.com/json-iterator/go/feature_iter_string.go b/vendor/github.com/json-iterator/go/feature_iter_string.go
index b76460046..adc487ea8 100644
--- a/vendor/github.com/json-iterator/go/feature_iter_string.go
+++ b/vendor/github.com/json-iterator/go/feature_iter_string.go
@@ -28,7 +28,7 @@ func (iter *Iterator) ReadString() (ret string) {
 		iter.skipThreeBytes('u', 'l', 'l')
 		return ""
 	}
-	iter.ReportError("ReadString", `expects " or n`)
+	iter.ReportError("ReadString", `expects " or n, but found `+string([]byte{c}))
 	return
 }
 
@@ -47,7 +47,7 @@ func (iter *Iterator) readStringSlowPath() (ret string) {
 			str = append(str, c)
 		}
 	}
-	iter.ReportError("ReadString", "unexpected end of input")
+	iter.ReportError("readStringSlowPath", "unexpected end of input")
 	return
 }
 
@@ -104,7 +104,7 @@ func (iter *Iterator) readEscapedChar(c byte, str []byte) []byte {
 	case 't':
 		str = append(str, '\t')
 	default:
-		iter.ReportError("ReadString",
+		iter.ReportError("readEscapedChar",
 			`invalid escape char after \`)
 		return nil
 	}
@@ -139,7 +139,7 @@ func (iter *Iterator) ReadStringAsSlice() (ret []byte) {
 		}
 		return copied
 	}
-	iter.ReportError("ReadString", `expects " or n`)
+	iter.ReportError("ReadStringAsSlice", `expects " or n, but found `+string([]byte{c}))
 	return
 }
 
@@ -156,7 +156,7 @@ func (iter *Iterator) readU4() (ret rune) {
 		} else if c >= 'A' && c <= 'F' {
 			ret = ret*16 + rune(c-'A'+10)
 		} else {
-			iter.ReportError("readU4", "expects 0~9 or a~f")
+			iter.ReportError("readU4", "expects 0~9 or a~f, but found "+string([]byte{c}))
 			return
 		}
 	}
diff --git a/vendor/github.com/json-iterator/go/feature_json_number.go b/vendor/github.com/json-iterator/go/feature_json_number.go
index 0439f6725..e187b200a 100644
--- a/vendor/github.com/json-iterator/go/feature_json_number.go
+++ b/vendor/github.com/json-iterator/go/feature_json_number.go
@@ -1,9 +1,25 @@
 package jsoniter
 
-import "encoding/json"
+import (
+	"encoding/json"
+	"strconv"
+)
 
 type Number string
 
+// String returns the literal text of the number.
+func (n Number) String() string { return string(n) }
+
+// Float64 returns the number as a float64.
+func (n Number) Float64() (float64, error) {
+	return strconv.ParseFloat(string(n), 64)
+}
+
+// Int64 returns the number as an int64.
+func (n Number) Int64() (int64, error) {
+	return strconv.ParseInt(string(n), 10, 64)
+}
+
 func CastJsonNumber(val interface{}) (string, bool) {
 	switch typedVal := val.(type) {
 	case json.Number:
diff --git a/vendor/github.com/json-iterator/go/feature_pool.go b/vendor/github.com/json-iterator/go/feature_pool.go
index 73962bc6f..52d38e685 100644
--- a/vendor/github.com/json-iterator/go/feature_pool.go
+++ b/vendor/github.com/json-iterator/go/feature_pool.go
@@ -28,6 +28,7 @@ func (cfg *frozenConfig) BorrowStream(writer io.Writer) *Stream {
 
 func (cfg *frozenConfig) ReturnStream(stream *Stream) {
 	stream.Error = nil
+	stream.Attachment = nil
 	select {
 	case cfg.streamPool <- stream:
 		return
@@ -48,6 +49,7 @@ func (cfg *frozenConfig) BorrowIterator(data []byte) *Iterator {
 
 func (cfg *frozenConfig) ReturnIterator(iter *Iterator) {
 	iter.Error = nil
+	iter.Attachment = nil
 	select {
 	case cfg.iteratorPool <- iter:
 		return
diff --git a/vendor/github.com/json-iterator/go/feature_reflect.go b/vendor/github.com/json-iterator/go/feature_reflect.go
index 05d91b49c..bed7764ed 100644
--- a/vendor/github.com/json-iterator/go/feature_reflect.go
+++ b/vendor/github.com/json-iterator/go/feature_reflect.go
@@ -72,24 +72,24 @@ func init() {
 	textUnmarshalerType = reflect.TypeOf((*encoding.TextUnmarshaler)(nil)).Elem()
 }
 
-type optionalDecoder struct {
-	valueType    reflect.Type
-	valueDecoder ValDecoder
+type OptionalDecoder struct {
+	ValueType    reflect.Type
+	ValueDecoder ValDecoder
 }
 
-func (decoder *optionalDecoder) Decode(ptr unsafe.Pointer, iter *Iterator) {
+func (decoder *OptionalDecoder) Decode(ptr unsafe.Pointer, iter *Iterator) {
 	if iter.ReadNil() {
 		*((*unsafe.Pointer)(ptr)) = nil
 	} else {
 		if *((*unsafe.Pointer)(ptr)) == nil {
 			//pointer to null, we have to allocate memory to hold the value
-			value := reflect.New(decoder.valueType)
+			value := reflect.New(decoder.ValueType)
 			newPtr := extractInterface(value.Interface()).word
-			decoder.valueDecoder.Decode(newPtr, iter)
+			decoder.ValueDecoder.Decode(newPtr, iter)
 			*((*uintptr)(ptr)) = uintptr(newPtr)
 		} else {
 			//reuse existing instance
-			decoder.valueDecoder.Decode(*((*unsafe.Pointer)(ptr)), iter)
+			decoder.ValueDecoder.Decode(*((*unsafe.Pointer)(ptr)), iter)
 		}
 	}
 }
@@ -113,11 +113,31 @@ func (decoder *deferenceDecoder) Decode(ptr unsafe.Pointer, iter *Iterator) {
 	}
 }
 
-type optionalEncoder struct {
+type OptionalEncoder struct {
+	ValueEncoder ValEncoder
+}
+
+func (encoder *OptionalEncoder) Encode(ptr unsafe.Pointer, stream *Stream) {
+	if *((*unsafe.Pointer)(ptr)) == nil {
+		stream.WriteNil()
+	} else {
+		encoder.ValueEncoder.Encode(*((*unsafe.Pointer)(ptr)), stream)
+	}
+}
+
+func (encoder *OptionalEncoder) EncodeInterface(val interface{}, stream *Stream) {
+	WriteToStream(val, stream, encoder)
+}
+
+func (encoder *OptionalEncoder) IsEmpty(ptr unsafe.Pointer) bool {
+	return *((*unsafe.Pointer)(ptr)) == nil
+}
+
+type optionalMapEncoder struct {
 	valueEncoder ValEncoder
 }
 
-func (encoder *optionalEncoder) Encode(ptr unsafe.Pointer, stream *Stream) {
+func (encoder *optionalMapEncoder) Encode(ptr unsafe.Pointer, stream *Stream) {
 	if *((*unsafe.Pointer)(ptr)) == nil {
 		stream.WriteNil()
 	} else {
@@ -125,15 +145,13 @@ func (encoder *optionalEncoder) Encode(ptr unsafe.Pointer, stream *Stream) {
 	}
 }
 
-func (encoder *optionalEncoder) EncodeInterface(val interface{}, stream *Stream) {
+func (encoder *optionalMapEncoder) EncodeInterface(val interface{}, stream *Stream) {
 	WriteToStream(val, stream, encoder)
 }
 
-func (encoder *optionalEncoder) IsEmpty(ptr unsafe.Pointer) bool {
-	if *((*unsafe.Pointer)(ptr)) == nil {
-		return true
-	}
-	return false
+func (encoder *optionalMapEncoder) IsEmpty(ptr unsafe.Pointer) bool {
+	p := *((*unsafe.Pointer)(ptr))
+	return p == nil || encoder.valueEncoder.IsEmpty(p)
 }
 
 type placeholderEncoder struct {
@@ -146,7 +164,7 @@ func (encoder *placeholderEncoder) Encode(ptr unsafe.Pointer, stream *Stream) {
 }
 
 func (encoder *placeholderEncoder) EncodeInterface(val interface{}, stream *Stream) {
-	WriteToStream(val, stream, encoder)
+	encoder.getRealEncoder().EncodeInterface(val, stream)
 }
 
 func (encoder *placeholderEncoder) IsEmpty(ptr unsafe.Pointer) bool {
@@ -154,11 +172,11 @@ func (encoder *placeholderEncoder) IsEmpty(ptr unsafe.Pointer) bool {
 }
 
 func (encoder *placeholderEncoder) getRealEncoder() ValEncoder {
-	for i := 0; i < 30; i++ {
+	for i := 0; i < 500; i++ {
 		realDecoder := encoder.cfg.getEncoderFromCache(encoder.cacheKey)
 		_, isPlaceholder := realDecoder.(*placeholderEncoder)
 		if isPlaceholder {
-			time.Sleep(time.Second)
+			time.Sleep(10 * time.Millisecond)
 		} else {
 			return realDecoder
 		}
@@ -172,11 +190,11 @@ type placeholderDecoder struct {
 }
 
 func (decoder *placeholderDecoder) Decode(ptr unsafe.Pointer, iter *Iterator) {
-	for i := 0; i < 30; i++ {
+	for i := 0; i < 500; i++ {
 		realDecoder := decoder.cfg.getDecoderFromCache(decoder.cacheKey)
 		_, isPlaceholder := realDecoder.(*placeholderDecoder)
 		if isPlaceholder {
-			time.Sleep(time.Second)
+			time.Sleep(10 * time.Millisecond)
 		} else {
 			realDecoder.Decode(ptr, iter)
 			return
@@ -256,7 +274,7 @@ func decoderOfType(cfg *frozenConfig, typ reflect.Type) (ValDecoder, error) {
 	if decoder != nil {
 		return decoder, nil
 	}
-	decoder = getTypeDecoderFromExtension(typ)
+	decoder = getTypeDecoderFromExtension(cfg, typ)
 	if decoder != nil {
 		cfg.addDecoderToCache(cacheKey, decoder)
 		return decoder, nil
@@ -267,6 +285,9 @@ func decoderOfType(cfg *frozenConfig, typ reflect.Type) (ValDecoder, error) {
 	for _, extension := range extensions {
 		decoder = extension.DecorateDecoder(typ, decoder)
 	}
+	for _, extension := range cfg.extensions {
+		decoder = extension.DecorateDecoder(typ, decoder)
+	}
 	cfg.addDecoderToCache(cacheKey, decoder)
 	return decoder, err
 }
@@ -289,7 +310,7 @@ func createDecoderOfType(cfg *frozenConfig, typ reflect.Type) (ValDecoder, error
 		templateInterface := reflect.New(typ).Elem().Interface()
 		var decoder ValDecoder = &unmarshalerDecoder{extractInterface(templateInterface)}
 		if typ.Kind() == reflect.Ptr {
-			decoder = &optionalDecoder{typ.Elem(), decoder}
+			decoder = &OptionalDecoder{typ.Elem(), decoder}
 		}
 		return decoder, nil
 	}
@@ -302,7 +323,7 @@ func createDecoderOfType(cfg *frozenConfig, typ reflect.Type) (ValDecoder, error
 		templateInterface := reflect.New(typ).Elem().Interface()
 		var decoder ValDecoder = &textUnmarshalerDecoder{extractInterface(templateInterface)}
 		if typ.Kind() == reflect.Ptr {
-			decoder = &optionalDecoder{typ.Elem(), decoder}
+			decoder = &OptionalDecoder{typ.Elem(), decoder}
 		}
 		return decoder, nil
 	}
@@ -423,7 +444,7 @@ func encoderOfType(cfg *frozenConfig, typ reflect.Type) (ValEncoder, error) {
 	if encoder != nil {
 		return encoder, nil
 	}
-	encoder = getTypeEncoderFromExtension(typ)
+	encoder = getTypeEncoderFromExtension(cfg, typ)
 	if encoder != nil {
 		cfg.addEncoderToCache(cacheKey, encoder)
 		return encoder, nil
@@ -434,6 +455,9 @@ func encoderOfType(cfg *frozenConfig, typ reflect.Type) (ValEncoder, error) {
 	for _, extension := range extensions {
 		encoder = extension.DecorateEncoder(typ, encoder)
 	}
+	for _, extension := range cfg.extensions {
+		encoder = extension.DecorateEncoder(typ, encoder)
+	}
 	cfg.addEncoderToCache(cacheKey, encoder)
 	return encoder, err
 }
@@ -452,7 +476,7 @@ func createEncoderOfType(cfg *frozenConfig, typ reflect.Type) (ValEncoder, error
 		return &jsoniterNumberCodec{}, nil
 	}
 	if typ.Implements(marshalerType) {
-		checkIsEmpty, err := createCheckIsEmpty(typ)
+		checkIsEmpty, err := createCheckIsEmpty(cfg, typ)
 		if err != nil {
 			return nil, err
 		}
@@ -462,12 +486,24 @@ func createEncoderOfType(cfg *frozenConfig, typ reflect.Type) (ValEncoder, error
 			checkIsEmpty:      checkIsEmpty,
 		}
 		if typ.Kind() == reflect.Ptr {
-			encoder = &optionalEncoder{encoder}
+			encoder = &OptionalEncoder{encoder}
+		}
+		return encoder, nil
+	}
+	if reflect.PtrTo(typ).Implements(marshalerType) {
+		checkIsEmpty, err := createCheckIsEmpty(cfg, reflect.PtrTo(typ))
+		if err != nil {
+			return nil, err
+		}
+		templateInterface := reflect.New(typ).Interface()
+		var encoder ValEncoder = &marshalerEncoder{
+			templateInterface: extractInterface(templateInterface),
+			checkIsEmpty:      checkIsEmpty,
 		}
 		return encoder, nil
 	}
 	if typ.Implements(textMarshalerType) {
-		checkIsEmpty, err := createCheckIsEmpty(typ)
+		checkIsEmpty, err := createCheckIsEmpty(cfg, typ)
 		if err != nil {
 			return nil, err
 		}
@@ -477,7 +513,7 @@ func createEncoderOfType(cfg *frozenConfig, typ reflect.Type) (ValEncoder, error
 			checkIsEmpty:      checkIsEmpty,
 		}
 		if typ.Kind() == reflect.Ptr {
-			encoder = &optionalEncoder{encoder}
+			encoder = &OptionalEncoder{encoder}
 		}
 		return encoder, nil
 	}
@@ -490,7 +526,7 @@ func createEncoderOfType(cfg *frozenConfig, typ reflect.Type) (ValEncoder, error
 	return createEncoderOfSimpleType(cfg, typ)
 }
 
-func createCheckIsEmpty(typ reflect.Type) (checkIsEmpty, error) {
+func createCheckIsEmpty(cfg *frozenConfig, typ reflect.Type) (checkIsEmpty, error) {
 	kind := typ.Kind()
 	switch kind {
 	case reflect.String:
@@ -535,9 +571,9 @@ func createCheckIsEmpty(typ reflect.Type) (checkIsEmpty, error) {
 	case reflect.Slice:
 		return &sliceEncoder{}, nil
 	case reflect.Map:
-		return &mapEncoder{}, nil
+		return encoderOfMap(cfg, typ)
 	case reflect.Ptr:
-		return &optionalEncoder{}, nil
+		return &OptionalEncoder{}, nil
 	default:
 		return nil, fmt.Errorf("unsupported type: %v", typ)
 	}
@@ -648,7 +684,7 @@ func decoderOfOptional(cfg *frozenConfig, typ reflect.Type) (ValDecoder, error)
 	if err != nil {
 		return nil, err
 	}
-	return &optionalDecoder{elemType, decoder}, nil
+	return &OptionalDecoder{elemType, decoder}, nil
 }
 
 func encoderOfOptional(cfg *frozenConfig, typ reflect.Type) (ValEncoder, error) {
@@ -657,9 +693,9 @@ func encoderOfOptional(cfg *frozenConfig, typ reflect.Type) (ValEncoder, error)
 	if err != nil {
 		return nil, err
 	}
-	encoder := &optionalEncoder{elemEncoder}
+	encoder := &OptionalEncoder{elemEncoder}
 	if elemType.Kind() == reflect.Map {
-		encoder = &optionalEncoder{encoder}
+		encoder = &OptionalEncoder{encoder}
 	}
 	return encoder, nil
 }
diff --git a/vendor/github.com/json-iterator/go/feature_reflect_array.go b/vendor/github.com/json-iterator/go/feature_reflect_array.go
index e23f187b7..d661fb6fe 100644
--- a/vendor/github.com/json-iterator/go/feature_reflect_array.go
+++ b/vendor/github.com/json-iterator/go/feature_reflect_array.go
@@ -21,7 +21,7 @@ func encoderOfArray(cfg *frozenConfig, typ reflect.Type) (ValEncoder, error) {
 		return nil, err
 	}
 	if typ.Elem().Kind() == reflect.Map {
-		encoder = &optionalEncoder{encoder}
+		encoder = &OptionalEncoder{encoder}
 	}
 	return &arrayEncoder{typ, typ.Elem(), encoder}, nil
 }
diff --git a/vendor/github.com/json-iterator/go/feature_reflect_extension.go b/vendor/github.com/json-iterator/go/feature_reflect_extension.go
index 3dd38299d..c129076bc 100644
--- a/vendor/github.com/json-iterator/go/feature_reflect_extension.go
+++ b/vendor/github.com/json-iterator/go/feature_reflect_extension.go
@@ -161,22 +161,31 @@ func RegisterExtension(extension Extension) {
 	extensions = append(extensions, extension)
 }
 
-func getTypeDecoderFromExtension(typ reflect.Type) ValDecoder {
-	decoder := _getTypeDecoderFromExtension(typ)
+func getTypeDecoderFromExtension(cfg *frozenConfig, typ reflect.Type) ValDecoder {
+	decoder := _getTypeDecoderFromExtension(cfg, typ)
 	if decoder != nil {
 		for _, extension := range extensions {
 			decoder = extension.DecorateDecoder(typ, decoder)
 		}
+		for _, extension := range cfg.extensions {
+			decoder = extension.DecorateDecoder(typ, decoder)
+		}
 	}
 	return decoder
 }
-func _getTypeDecoderFromExtension(typ reflect.Type) ValDecoder {
+func _getTypeDecoderFromExtension(cfg *frozenConfig, typ reflect.Type) ValDecoder {
 	for _, extension := range extensions {
 		decoder := extension.CreateDecoder(typ)
 		if decoder != nil {
 			return decoder
 		}
 	}
+	for _, extension := range cfg.extensions {
+		decoder := extension.CreateDecoder(typ)
+		if decoder != nil {
+			return decoder
+		}
+	}
 	typeName := typ.String()
 	decoder := typeDecoders[typeName]
 	if decoder != nil {
@@ -185,29 +194,38 @@ func _getTypeDecoderFromExtension(typ reflect.Type) ValDecoder {
 	if typ.Kind() == reflect.Ptr {
 		decoder := typeDecoders[typ.Elem().String()]
 		if decoder != nil {
-			return &optionalDecoder{typ.Elem(), decoder}
+			return &OptionalDecoder{typ.Elem(), decoder}
 		}
 	}
 	return nil
 }
 
-func getTypeEncoderFromExtension(typ reflect.Type) ValEncoder {
-	encoder := _getTypeEncoderFromExtension(typ)
+func getTypeEncoderFromExtension(cfg *frozenConfig, typ reflect.Type) ValEncoder {
+	encoder := _getTypeEncoderFromExtension(cfg, typ)
 	if encoder != nil {
 		for _, extension := range extensions {
 			encoder = extension.DecorateEncoder(typ, encoder)
 		}
+		for _, extension := range cfg.extensions {
+			encoder = extension.DecorateEncoder(typ, encoder)
+		}
 	}
 	return encoder
 }
 
-func _getTypeEncoderFromExtension(typ reflect.Type) ValEncoder {
+func _getTypeEncoderFromExtension(cfg *frozenConfig, typ reflect.Type) ValEncoder {
 	for _, extension := range extensions {
 		encoder := extension.CreateEncoder(typ)
 		if encoder != nil {
 			return encoder
 		}
 	}
+	for _, extension := range cfg.extensions {
+		encoder := extension.CreateEncoder(typ)
+		if encoder != nil {
+			return encoder
+		}
+	}
 	typeName := typ.String()
 	encoder := typeEncoders[typeName]
 	if encoder != nil {
@@ -216,7 +234,7 @@ func _getTypeEncoderFromExtension(typ reflect.Type) ValEncoder {
 	if typ.Kind() == reflect.Ptr {
 		encoder := typeEncoders[typ.Elem().String()]
 		if encoder != nil {
-			return &optionalEncoder{encoder}
+			return &OptionalEncoder{encoder}
 		}
 	}
 	return nil
@@ -254,7 +272,7 @@ func describeStruct(cfg *frozenConfig, typ reflect.Type) (*StructDescriptor, err
 				for _, binding := range structDescriptor.Fields {
 					binding.levels = append([]int{i}, binding.levels...)
 					omitempty := binding.Encoder.(*structFieldEncoder).omitempty
-					binding.Encoder = &optionalEncoder{binding.Encoder}
+					binding.Encoder = &OptionalEncoder{binding.Encoder}
 					binding.Encoder = &structFieldEncoder{&field, binding.Encoder, omitempty}
 					binding.Decoder = &deferenceDecoder{field.Type.Elem(), binding.Decoder}
 					binding.Decoder = &structFieldDecoder{&field, binding.Decoder}
@@ -269,7 +287,7 @@ func describeStruct(cfg *frozenConfig, typ reflect.Type) (*StructDescriptor, err
 		if decoder == nil {
 			var err error
 			decoder, err = decoderOfType(cfg, field.Type)
-			if err != nil {
+			if len(fieldNames) > 0 && err != nil {
 				return nil, err
 			}
 		}
@@ -277,12 +295,13 @@ func describeStruct(cfg *frozenConfig, typ reflect.Type) (*StructDescriptor, err
 		if encoder == nil {
 			var err error
 			encoder, err = encoderOfType(cfg, field.Type)
-			if err != nil {
+			if len(fieldNames) > 0 && err != nil {
 				return nil, err
 			}
-			// map is stored as pointer in the struct
-			if field.Type.Kind() == reflect.Map {
-				encoder = &optionalEncoder{encoder}
+			// map is stored as pointer in the struct,
+			// and treat nil or empty map as empty field
+			if encoder != nil && field.Type.Kind() == reflect.Map {
+				encoder = &optionalMapEncoder{encoder}
 			}
 		}
 		binding := &Binding{
@@ -323,6 +342,9 @@ func createStructDescriptor(cfg *frozenConfig, typ reflect.Type, bindings []*Bin
 	for _, extension := range extensions {
 		extension.UpdateStructDescriptor(structDescriptor)
 	}
+	for _, extension := range cfg.extensions {
+		extension.UpdateStructDescriptor(structDescriptor)
+	}
 	processTags(structDescriptor, cfg)
 	// merge normal & embedded bindings & sort with original order
 	allBindings := sortableBindings(append(embeddedBindings, structDescriptor.Fields...))
diff --git a/vendor/github.com/json-iterator/go/feature_reflect_native.go b/vendor/github.com/json-iterator/go/feature_reflect_native.go
index b37dab3d8..95bd1e87c 100644
--- a/vendor/github.com/json-iterator/go/feature_reflect_native.go
+++ b/vendor/github.com/json-iterator/go/feature_reflect_native.go
@@ -4,6 +4,7 @@ import (
 	"encoding"
 	"encoding/base64"
 	"encoding/json"
+	"reflect"
 	"unsafe"
 )
 
@@ -31,7 +32,9 @@ type intCodec struct {
 }
 
 func (codec *intCodec) Decode(ptr unsafe.Pointer, iter *Iterator) {
-	*((*int)(ptr)) = iter.ReadInt()
+	if !iter.ReadNil() {
+		*((*int)(ptr)) = iter.ReadInt()
+	}
 }
 
 func (codec *intCodec) Encode(ptr unsafe.Pointer, stream *Stream) {
@@ -50,7 +53,9 @@ type uintptrCodec struct {
 }
 
 func (codec *uintptrCodec) Decode(ptr unsafe.Pointer, iter *Iterator) {
-	*((*uintptr)(ptr)) = uintptr(iter.ReadUint64())
+	if !iter.ReadNil() {
+		*((*uintptr)(ptr)) = uintptr(iter.ReadUint64())
+	}
 }
 
 func (codec *uintptrCodec) Encode(ptr unsafe.Pointer, stream *Stream) {
@@ -69,7 +74,9 @@ type int8Codec struct {
 }
 
 func (codec *int8Codec) Decode(ptr unsafe.Pointer, iter *Iterator) {
-	*((*int8)(ptr)) = iter.ReadInt8()
+	if !iter.ReadNil() {
+		*((*int8)(ptr)) = iter.ReadInt8()
+	}
 }
 
 func (codec *int8Codec) Encode(ptr unsafe.Pointer, stream *Stream) {
@@ -88,7 +95,9 @@ type int16Codec struct {
 }
 
 func (codec *int16Codec) Decode(ptr unsafe.Pointer, iter *Iterator) {
-	*((*int16)(ptr)) = iter.ReadInt16()
+	if !iter.ReadNil() {
+		*((*int16)(ptr)) = iter.ReadInt16()
+	}
 }
 
 func (codec *int16Codec) Encode(ptr unsafe.Pointer, stream *Stream) {
@@ -107,7 +116,9 @@ type int32Codec struct {
 }
 
 func (codec *int32Codec) Decode(ptr unsafe.Pointer, iter *Iterator) {
-	*((*int32)(ptr)) = iter.ReadInt32()
+	if !iter.ReadNil() {
+		*((*int32)(ptr)) = iter.ReadInt32()
+	}
 }
 
 func (codec *int32Codec) Encode(ptr unsafe.Pointer, stream *Stream) {
@@ -126,7 +137,9 @@ type int64Codec struct {
 }
 
 func (codec *int64Codec) Decode(ptr unsafe.Pointer, iter *Iterator) {
-	*((*int64)(ptr)) = iter.ReadInt64()
+	if !iter.ReadNil() {
+		*((*int64)(ptr)) = iter.ReadInt64()
+	}
 }
 
 func (codec *int64Codec) Encode(ptr unsafe.Pointer, stream *Stream) {
@@ -145,7 +158,10 @@ type uintCodec struct {
 }
 
 func (codec *uintCodec) Decode(ptr unsafe.Pointer, iter *Iterator) {
-	*((*uint)(ptr)) = iter.ReadUint()
+	if !iter.ReadNil() {
+		*((*uint)(ptr)) = iter.ReadUint()
+		return
+	}
 }
 
 func (codec *uintCodec) Encode(ptr unsafe.Pointer, stream *Stream) {
@@ -164,7 +180,9 @@ type uint8Codec struct {
 }
 
 func (codec *uint8Codec) Decode(ptr unsafe.Pointer, iter *Iterator) {
-	*((*uint8)(ptr)) = iter.ReadUint8()
+	if !iter.ReadNil() {
+		*((*uint8)(ptr)) = iter.ReadUint8()
+	}
 }
 
 func (codec *uint8Codec) Encode(ptr unsafe.Pointer, stream *Stream) {
@@ -183,7 +201,9 @@ type uint16Codec struct {
 }
 
 func (codec *uint16Codec) Decode(ptr unsafe.Pointer, iter *Iterator) {
-	*((*uint16)(ptr)) = iter.ReadUint16()
+	if !iter.ReadNil() {
+		*((*uint16)(ptr)) = iter.ReadUint16()
+	}
 }
 
 func (codec *uint16Codec) Encode(ptr unsafe.Pointer, stream *Stream) {
@@ -202,7 +222,9 @@ type uint32Codec struct {
 }
 
 func (codec *uint32Codec) Decode(ptr unsafe.Pointer, iter *Iterator) {
-	*((*uint32)(ptr)) = iter.ReadUint32()
+	if !iter.ReadNil() {
+		*((*uint32)(ptr)) = iter.ReadUint32()
+	}
 }
 
 func (codec *uint32Codec) Encode(ptr unsafe.Pointer, stream *Stream) {
@@ -221,7 +243,9 @@ type uint64Codec struct {
 }
 
 func (codec *uint64Codec) Decode(ptr unsafe.Pointer, iter *Iterator) {
-	*((*uint64)(ptr)) = iter.ReadUint64()
+	if !iter.ReadNil() {
+		*((*uint64)(ptr)) = iter.ReadUint64()
+	}
 }
 
 func (codec *uint64Codec) Encode(ptr unsafe.Pointer, stream *Stream) {
@@ -240,7 +264,9 @@ type float32Codec struct {
 }
 
 func (codec *float32Codec) Decode(ptr unsafe.Pointer, iter *Iterator) {
-	*((*float32)(ptr)) = iter.ReadFloat32()
+	if !iter.ReadNil() {
+		*((*float32)(ptr)) = iter.ReadFloat32()
+	}
 }
 
 func (codec *float32Codec) Encode(ptr unsafe.Pointer, stream *Stream) {
@@ -259,7 +285,9 @@ type float64Codec struct {
 }
 
 func (codec *float64Codec) Decode(ptr unsafe.Pointer, iter *Iterator) {
-	*((*float64)(ptr)) = iter.ReadFloat64()
+	if !iter.ReadNil() {
+		*((*float64)(ptr)) = iter.ReadFloat64()
+	}
 }
 
 func (codec *float64Codec) Encode(ptr unsafe.Pointer, stream *Stream) {
@@ -278,7 +306,9 @@ type boolCodec struct {
 }
 
 func (codec *boolCodec) Decode(ptr unsafe.Pointer, iter *Iterator) {
-	*((*bool)(ptr)) = iter.ReadBool()
+	if !iter.ReadNil() {
+		*((*bool)(ptr)) = iter.ReadBool()
+	}
 }
 
 func (codec *boolCodec) Encode(ptr unsafe.Pointer, stream *Stream) {
@@ -297,7 +327,42 @@ type emptyInterfaceCodec struct {
 }
 
 func (codec *emptyInterfaceCodec) Decode(ptr unsafe.Pointer, iter *Iterator) {
-	*((*interface{})(ptr)) = iter.Read()
+	existing := *((*interface{})(ptr))
+
+	// Checking for both typed and untyped nil pointers.
+	if existing != nil &&
+		reflect.TypeOf(existing).Kind() == reflect.Ptr &&
+		!reflect.ValueOf(existing).IsNil() {
+
+		var ptrToExisting interface{}
+		for {
+			elem := reflect.ValueOf(existing).Elem()
+			if elem.Kind() != reflect.Ptr || elem.IsNil() {
+				break
+			}
+			ptrToExisting = existing
+			existing = elem.Interface()
+		}
+
+		if iter.ReadNil() {
+			if ptrToExisting != nil {
+				nilPtr := reflect.Zero(reflect.TypeOf(ptrToExisting).Elem())
+				reflect.ValueOf(ptrToExisting).Elem().Set(nilPtr)
+			} else {
+				*((*interface{})(ptr)) = nil
+			}
+		} else {
+			iter.ReadVal(existing)
+		}
+
+		return
+	}
+
+	if iter.ReadNil() {
+		*((*interface{})(ptr)) = nil
+	} else {
+		*((*interface{})(ptr)) = iter.Read()
+	}
 }
 
 func (codec *emptyInterfaceCodec) Encode(ptr unsafe.Pointer, stream *Stream) {
@@ -309,7 +374,8 @@ func (codec *emptyInterfaceCodec) EncodeInterface(val interface{}, stream *Strea
 }
 
 func (codec *emptyInterfaceCodec) IsEmpty(ptr unsafe.Pointer) bool {
-	return ptr == nil
+	emptyInterface := (*emptyInterface)(ptr)
+	return emptyInterface.typ == nil
 }
 
 type nonEmptyInterfaceCodec struct {
@@ -326,15 +392,20 @@ func (codec *nonEmptyInterfaceCodec) Decode(ptr unsafe.Pointer, iter *Iterator)
 	e.typ = nonEmptyInterface.itab.typ
 	e.word = nonEmptyInterface.word
 	iter.ReadVal(&i)
+	if e.word == nil {
+		nonEmptyInterface.itab = nil
+	}
 	nonEmptyInterface.word = e.word
 }
 
 func (codec *nonEmptyInterfaceCodec) Encode(ptr unsafe.Pointer, stream *Stream) {
 	nonEmptyInterface := (*nonEmptyInterface)(ptr)
 	var i interface{}
-	e := (*emptyInterface)(unsafe.Pointer(&i))
-	e.typ = nonEmptyInterface.itab.typ
-	e.word = nonEmptyInterface.word
+	if nonEmptyInterface.itab != nil {
+		e := (*emptyInterface)(unsafe.Pointer(&i))
+		e.typ = nonEmptyInterface.itab.typ
+		e.word = nonEmptyInterface.word
+	}
 	stream.WriteVal(i)
 }
 
@@ -370,7 +441,15 @@ type jsonNumberCodec struct {
 }
 
 func (codec *jsonNumberCodec) Decode(ptr unsafe.Pointer, iter *Iterator) {
-	*((*json.Number)(ptr)) = json.Number([]byte(iter.readNumberAsString()))
+	switch iter.WhatIsNext() {
+	case StringValue:
+		*((*json.Number)(ptr)) = json.Number(iter.ReadString())
+	case NilValue:
+		iter.skipFourBytes('n', 'u', 'l', 'l')
+		*((*json.Number)(ptr)) = ""
+	default:
+		*((*json.Number)(ptr)) = json.Number([]byte(iter.readNumberAsString()))
+	}
 }
 
 func (codec *jsonNumberCodec) Encode(ptr unsafe.Pointer, stream *Stream) {
@@ -389,7 +468,15 @@ type jsoniterNumberCodec struct {
 }
 
 func (codec *jsoniterNumberCodec) Decode(ptr unsafe.Pointer, iter *Iterator) {
-	*((*Number)(ptr)) = Number([]byte(iter.readNumberAsString()))
+	switch iter.WhatIsNext() {
+	case StringValue:
+		*((*Number)(ptr)) = Number(iter.ReadString())
+	case NilValue:
+		iter.skipFourBytes('n', 'u', 'l', 'l')
+		*((*Number)(ptr)) = ""
+	default:
+		*((*Number)(ptr)) = Number([]byte(iter.readNumberAsString()))
+	}
 }
 
 func (codec *jsoniterNumberCodec) Encode(ptr unsafe.Pointer, stream *Stream) {
@@ -521,7 +608,7 @@ type stringModeNumberDecoder struct {
 func (decoder *stringModeNumberDecoder) Decode(ptr unsafe.Pointer, iter *Iterator) {
 	c := iter.nextToken()
 	if c != '"' {
-		iter.ReportError("stringModeNumberDecoder", `expect "`)
+		iter.ReportError("stringModeNumberDecoder", `expect ", but found `+string([]byte{c}))
 		return
 	}
 	decoder.elemDecoder.Decode(ptr, iter)
@@ -530,7 +617,7 @@ func (decoder *stringModeNumberDecoder) Decode(ptr unsafe.Pointer, iter *Iterato
 	}
 	c = iter.readByte()
 	if c != '"' {
-		iter.ReportError("stringModeNumberDecoder", `expect "`)
+		iter.ReportError("stringModeNumberDecoder", `expect ", but found `+string([]byte{c}))
 		return
 	}
 }
@@ -595,7 +682,12 @@ func (encoder *marshalerEncoder) Encode(ptr unsafe.Pointer, stream *Stream) {
 	templateInterface := encoder.templateInterface
 	templateInterface.word = ptr
 	realInterface := (*interface{})(unsafe.Pointer(&templateInterface))
-	marshaler := (*realInterface).(json.Marshaler)
+	marshaler, ok := (*realInterface).(json.Marshaler)
+	if !ok {
+		stream.WriteVal(nil)
+		return
+	}
+
 	bytes, err := marshaler.MarshalJSON()
 	if err != nil {
 		stream.Error = err
diff --git a/vendor/github.com/json-iterator/go/feature_reflect_slice.go b/vendor/github.com/json-iterator/go/feature_reflect_slice.go
index 7377eec7b..51a8daecf 100644
--- a/vendor/github.com/json-iterator/go/feature_reflect_slice.go
+++ b/vendor/github.com/json-iterator/go/feature_reflect_slice.go
@@ -21,7 +21,7 @@ func encoderOfSlice(cfg *frozenConfig, typ reflect.Type) (ValEncoder, error) {
 		return nil, err
 	}
 	if typ.Elem().Kind() == reflect.Map {
-		encoder = &optionalEncoder{encoder}
+		encoder = &OptionalEncoder{encoder}
 	}
 	return &sliceEncoder{typ, typ.Elem(), encoder}, nil
 }
@@ -127,12 +127,10 @@ func growOne(slice *sliceHeader, sliceType reflect.Type, elementType reflect.Typ
 	newVal := reflect.MakeSlice(sliceType, newLen, newCap)
 	dst := unsafe.Pointer(newVal.Pointer())
 	// copy old array into new array
-	originalBytesCount := uintptr(slice.Len) * elementType.Size()
-	srcPtr := (*[1 << 30]byte)(slice.Data)
-	dstPtr := (*[1 << 30]byte)(dst)
-	for i := uintptr(0); i < originalBytesCount; i++ {
-		dstPtr[i] = srcPtr[i]
-	}
+	originalBytesCount := slice.Len * int(elementType.Size())
+	srcSliceHeader := (unsafe.Pointer)(&sliceHeader{slice.Data, originalBytesCount, originalBytesCount})
+	dstSliceHeader := (unsafe.Pointer)(&sliceHeader{dst, originalBytesCount, originalBytesCount})
+	copy(*(*[]byte)(dstSliceHeader), *(*[]byte)(srcSliceHeader))
 	slice.Data = dst
 	slice.Len = newLen
 	slice.Cap = newCap
diff --git a/vendor/github.com/json-iterator/go/feature_reflect_struct_decoder.go b/vendor/github.com/json-iterator/go/feature_reflect_struct_decoder.go
index b3417fd73..e6ced77c2 100644
--- a/vendor/github.com/json-iterator/go/feature_reflect_struct_decoder.go
+++ b/vendor/github.com/json-iterator/go/feature_reflect_struct_decoder.go
@@ -427,8 +427,18 @@ func (decoder *generalStructDecoder) Decode(ptr unsafe.Pointer, iter *Iterator)
 	if !iter.readObjectStart() {
 		return
 	}
-	fieldBytes := iter.readObjectFieldAsBytes()
-	field := *(*string)(unsafe.Pointer(&fieldBytes))
+	var fieldBytes []byte
+	var field string
+	if iter.cfg.objectFieldMustBeSimpleString {
+		fieldBytes = iter.readObjectFieldAsBytes()
+		field = *(*string)(unsafe.Pointer(&fieldBytes))
+	} else {
+		field = iter.ReadString()
+		c := iter.nextToken()
+		if c != ':' {
+			iter.ReportError("ReadObject", "expect : after object field, but found "+string([]byte{c}))
+		}
+	}
 	fieldDecoder := decoder.fields[strings.ToLower(field)]
 	if fieldDecoder == nil {
 		iter.Skip()
@@ -436,8 +446,16 @@ func (decoder *generalStructDecoder) Decode(ptr unsafe.Pointer, iter *Iterator)
 		fieldDecoder.Decode(ptr, iter)
 	}
 	for iter.nextToken() == ',' {
-		fieldBytes = iter.readObjectFieldAsBytes()
-		field = *(*string)(unsafe.Pointer(&fieldBytes))
+		if iter.cfg.objectFieldMustBeSimpleString {
+			fieldBytes := iter.readObjectFieldAsBytes()
+			field = *(*string)(unsafe.Pointer(&fieldBytes))
+		} else {
+			field = iter.ReadString()
+			c := iter.nextToken()
+			if c != ':' {
+				iter.ReportError("ReadObject", "expect : after object field, but found "+string([]byte{c}))
+			}
+		}
 		fieldDecoder = decoder.fields[strings.ToLower(field)]
 		if fieldDecoder == nil {
 			iter.Skip()
diff --git a/vendor/github.com/json-iterator/go/feature_stream.go b/vendor/github.com/json-iterator/go/feature_stream.go
index 9c8470a03..97355eb5b 100644
--- a/vendor/github.com/json-iterator/go/feature_stream.go
+++ b/vendor/github.com/json-iterator/go/feature_stream.go
@@ -4,15 +4,16 @@ import (
 	"io"
 )
 
-// Stream is a io.Writer like object, with JSON specific write functions.
+// stream is a io.Writer like object, with JSON specific write functions.
 // Error is not returned as return value, but stored as Error member on this stream instance.
 type Stream struct {
-	cfg       *frozenConfig
-	out       io.Writer
-	buf       []byte
-	n         int
-	Error     error
-	indention int
+	cfg        *frozenConfig
+	out        io.Writer
+	buf        []byte
+	n          int
+	Error      error
+	indention  int
+	Attachment interface{} // open for customized encoder
 }
 
 // NewStream create new stream instance.
@@ -191,6 +192,9 @@ func (stream *Stream) ensure(minimal int) {
 func (stream *Stream) growAtLeast(minimal int) {
 	if stream.out != nil {
 		stream.Flush()
+		if stream.Available() >= minimal {
+			return
+		}
 	}
 	toGrow := len(stream.buf)
 	if toGrow < minimal {
@@ -280,8 +284,7 @@ func (stream *Stream) WriteArrayStart() {
 
 // WriteEmptyArray write []
 func (stream *Stream) WriteEmptyArray() {
-	stream.writeByte('[')
-	stream.writeByte(']')
+	stream.writeTwoBytes('[', ']')
 }
 
 // WriteArrayEnd write ] with possible indention