golang codec

golang bytes to struct and struct to bytes

.gitattributes

@@ -0,0 +1,22 @@
+# Auto detect text files and perform LF normalization
+* text=auto
+
+# Custom for Visual Studio
+*.cs     diff=csharp
+*.sln    merge=union
+*.csproj merge=union
+*.vbproj merge=union
+*.fsproj merge=union
+*.dbproj merge=union
+
+# Standard to msysgit
+*.doc	 diff=astextplain
+*.DOC	 diff=astextplain
+*.docx diff=astextplain
+*.DOCX diff=astextplain
+*.dot  diff=astextplain
+*.DOT  diff=astextplain
+*.pdf  diff=astextplain
+*.PDF	 diff=astextplain
+*.rtf	 diff=astextplain
+*.RTF	 diff=astextplain

.gitignore

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+# Compiled Object files, Static and Dynamic libs (Shared Objects)
+*.o
+*.a
+*.so
+
+# Folders
+_obj
+_test
+
+# Architecture specific extensions/prefixes
+*.[568vq]
+[568vq].out
+
+*.cgo1.go
+*.cgo2.c
+_cgo_defun.c
+_cgo_gotypes.go
+_cgo_export.*
+
+_testmain.go
+
+*.exe
+*.test
+
+# =========================
+# Operating System Files
+# =========================
+
+# OSX
+# =========================
+
+.DS_Store
+.AppleDouble
+.LSOverride
+
+# Icon must ends with two \r.
+Icon
+
+# Thumbnails
+._*
+
+# Files that might appear on external disk
+.Spotlight-V100
+.Trashes
+
+# Windows
+# =========================
+
+# Windows image file caches
+Thumbs.db
+ehthumbs.db
+
+# Folder config file
+Desktop.ini
+
+# Recycle Bin used on file shares
+$RECYCLE.BIN/
+
+# Windows Installer files
+*.cab
+*.msi
+*.msm
+*.msp

codec/decode.go

@@ -0,0 +1,166 @@
+package codec
+
+import (
+	"bytes"
+	"runtime"
+	"reflect"
+	"fmt"
+	"encoding/binary"
+)
+
+func Decode(data []byte, v interface {}) error {
+	de := new(decoder)
+	de.buf = bytes.NewBuffer(data)
+	if err := de.unmarshal(v); err != nil {
+		return err
+	}
+	return nil
+}
+
+type decoder struct {
+	buf *bytes.Buffer
+}
+
+func (this *decoder) unmarshal(v interface {}) (err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			if _, ok := r.(runtime.Error); ok {
+				panic(r)
+			}
+			if s, ok := r.(string); ok {
+				panic(s)
+			}
+			err = r.(error)
+		}
+	}()
+	this.reflect(v)
+	return nil
+}
+
+func (this *decoder) reflect(v interface {}) {
+	if reflect.TypeOf(v).Kind() != reflect.Ptr {
+		this.error(fmt.Errorf("Interface's kind must be reflect.Ptr."))
+	}
+	rv := reflect.ValueOf(v).Elem()
+	if !rv.CanSet() {
+		this.error(fmt.Errorf("Reflect value can't set."))
+	}
+	rvCount := rv.NumField()
+	for i := 0; i < rvCount; i++ {
+		this.decode(rv.Field(i))
+	}
+}
+
+func (this *decoder) decode(rv reflect.Value) {
+	switch rv.Kind() {
+	case reflect.Array:
+		this.decodeArray(rv)
+	case reflect.Slice:
+		this.decodeSlice(rv)
+	case reflect.Struct:
+		this.decodeStruct(rv)
+	case reflect.String:
+		this.decodeString(rv)
+	default:
+		this.decodeValue(rv)
+	}
+}
+
+func (this *decoder) decodeArray(rv reflect.Value) {
+	rvLen := rv.Len()
+	if rvLen <= 0 {
+		return
+	}
+
+	firstElem := rv.Index(0)
+	switch firstElem.Kind() {
+	case reflect.Uint8:
+		valArr := this.buf.Next(rvLen)
+		reflect.Copy(rv, reflect.ValueOf(valArr))
+	case reflect.Struct:
+		for i := 0; i < rvLen; i++ {
+			this.decodeStruct(rv.Index(i))
+		}
+	case reflect.String:
+		this.decodeString(rv)
+	}
+}
+
+func (this *decoder) decodeSlice(rv reflect.Value) {
+	var rvLen uint32
+	binary.Read(this.buf, binary.LittleEndian, &rvLen)
+
+	if rvLen <= 0 {
+		return
+	}
+
+	newRv := reflect.MakeSlice(rv.Type(), int(rvLen), int(rvLen))
+	rv.Set(newRv)
+	this.decodeArray(rv)
+}
+
+func (this *decoder) decodeStruct(rv reflect.Value) {
+	rvCount := rv.NumField()
+	for i := 0; i < rvCount; i++ {
+		this.decode(rv.Field(i))
+	}
+}
+
+func (this *decoder) decodeString(rv reflect.Value)  {
+	var rvLen uint32
+	binary.Read(this.buf, binary.LittleEndian, &rvLen)
+	if rvLen <= 0 {
+		return
+	}
+	strBytes := this.buf.Next(int(rvLen))
+	rv.SetString(string(strBytes))
+}
+
+func (this *decoder) decodeValue(rv reflect.Value) {
+	switch rv.Kind() {
+	case reflect.Bool:
+		var val uint8
+		binary.Read(this.buf, binary.LittleEndian, &val)
+		if val > 0 {
+			rv.SetBool(true)
+		}
+	case reflect.Uint8:
+		var val uint8
+		binary.Read(this.buf, binary.LittleEndian, &val)
+		rv.SetUint(uint64(val))
+	case reflect.Int16:
+		var val int16
+		binary.Read(this.buf, binary.LittleEndian, &val)
+		rv.SetInt(int64(val))
+	case reflect.Uint16:
+		var val uint16
+		binary.Read(this.buf, binary.LittleEndian, &val)
+		rv.SetUint(uint64(val))
+	case reflect.Int32:
+		var val int32
+		binary.Read(this.buf, binary.LittleEndian, &val)
+		rv.SetInt(int64(val))
+	case reflect.Uint32:
+		var val uint32
+		binary.Read(this.buf, binary.LittleEndian, &val)
+		rv.SetUint(uint64(val))
+	case reflect.Float32:
+		var val float32
+		binary.Read(this.buf, binary.LittleEndian, &val)
+		rv.SetFloat(float64(val))
+	case reflect.Int64:
+		var val int64
+		binary.Read(this.buf, binary.LittleEndian, &val)
+		rv.SetInt(val)
+	case reflect.Uint64:
+		var val uint64
+		binary.Read(this.buf, binary.LittleEndian, &val)
+		rv.SetUint(val)
+	default:
+		this.error(fmt.Errorf("Can't decode %v type", rv.Kind()))
+	}
+}
+
+func (this *decoder) error(err error) {
+	panic(err)
+}