【分享】自定义arraybuffer数据结构

Creator 2.x
#1

当前开发者大部分都是使用的protobubffer那套方案来做前后端的数据交流通信了，这个自定义的arraybuffer方案，是以前做app的时候写的，思路整理了一下，可以看看

ByteArray.ts

export class ByteArray {
endian: boolean;
bytesBuff: any;
bytesBuffView: DataView;
fmt: any;
data: any;
position: any;
length: any;

/**
 * @param bytesBuff 请求解码的数据
 * @param endian 字节序
 */
constructor(bytesBuff = null, endian = false) {
    this.bytesBuff = bytesBuff;
    this.bytesBuffView = null;
    if (bytesBuff) {
        this.bytesBuffView = new DataView(this.bytesBuff);
    } else {
        this.fmt = [];
        this.data = [];
    }
    this.endian = endian;
    this.position = 0;
    this.length = 0;
}

destory() {
    this.bytesBuff = null;
    this.fmt = null;
    this.data = null;
    this.bytesBuff = null;
    this.bytesBuffView = null;
}

readByte() {
    var va1 = this.bytesBuffView.getInt8(this.position);
    this.position += 1;
    return va1;
}

writeByte(b) {
    this.fmt.push('b');
    this.data.push(b);
    this.length += 1;
}

readShort() {
    var val = this.bytesBuffView.getInt16(this.position, this.endian);
    this.position += 2;
    return val;
}

writeShort(h) {
    this.fmt.push('h');
    this.data.push(h);
    this.length += 2;
}

readLong() {
    var val = this.bytesBuffView.getBigUint64(this.position, this.endian);
    this.position += 8;
    return val;
}

writeLong(d) {
    this.fmt.push("l");
    this.data.push(d);
    this.length += 8;
}

readInt() {
    var val = this.bytesBuffView.getInt32(this.position, this.endian);
    this.position += 4;
    return val;
}

writeInt(i) {
    this.fmt.push('i');
    this.data.push(i);
    this.length += 4;
}

readDouble() {
    var val = this.bytesBuffView.getFloat64(this.position, this.endian);
    this.position += 8;
    return val;
}

writeDouble(d) {
    this.fmt.push('d');
    this.data.push(d);
    this.length += 8;
}

readString() {
    var l = this.readShort();
    if (l < 1) return '';
    var u8Arr = new Uint8Array(this.bytesBuff, this.position);
    var arr = [];
    for (var i = 0; i < l; i++) {
        arr[i] = u8Arr[i];
    }
    var ret = decode(arr);
    this.position += l;
    return ret;
}

writeString(s) {
    var arr = encode(s);
    this.writeShort(arr.length);
    this.fmt.push('s');
    this.data.push(this._uintCharArrToString(arr));
    this.length += arr.length;
}

writeMultiByte(str) {
    var len = str.length;
    for (var i = 0; i < len; i++) {
        this.writeByte(str.charCodeAt(i));
    }
    this.length += len;
}

_uintCharArrToString(arr) {
    var ret = '';
    for (var i = 0; i < arr.length; i++) {
        ret += String.fromCharCode(arr[i]);
    }
    return ret;
}

getbytes() {
    if (this.bytesBuff) {
        return this.bytesBuff;
    } else {
        var buff = new ArrayBuffer(this.length);
        var buffView = new DataView(buff);
        var len = this.fmt.length;
        var dataType = '';
        var elm: any = 0;
        var index = 0;
        for (var i = 0; i < len; i++) {
            dataType = this.fmt[i];
            elm = this.data[i];
            if (dataType == 'b') {
                buffView.setInt8(index, elm);
                index += 1;
            } else if (dataType == 'h') {
                buffView.setInt16(index, elm, this.endian);
                index += 2;
            } else if (dataType == 'i') {
                buffView.setInt32(index, elm, this.endian);
                index += 4;
            } else if (dataType == 'd') {
                buffView.setFloat64(index, elm, this.endian);
                index += 8;
            } else if (dataType == "l") {
                buffView.setBigUint64(index, elm, this.endian);
                index += 8;
            } else if (dataType == 's') {
                index += this._fillArryBuffWithString(elm, buff, index);
            }
        }
        return buff;
    }
}

_fillArryBuffWithString(strdata, arryBuff, offset) {
    if (!strdata) {
        return;
    }
    var len = strdata.length;
    var tempdataView = new DataView(arryBuff, offset);
    for (var i = 0; i < len; i++) {
        tempdataView.setUint8(i, strdata.charCodeAt(i));
    }
    return len;
}

}

function decode(dotNetBytes) {
var result = “”;
var i = 0;
var c = 0;
var c1 = 0;
var c2 = 0;
var c3 = 0;
if (dotNetBytes.length >= 3) {
if ((dotNetBytes[0] & 0xef) == 0xef
&& (dotNetBytes[1] & 0xbb) == 0xbb
&& (dotNetBytes[2] & 0xbf) == 0xbf) {
i = 3;
}
}

while (i < dotNetBytes.length) {
    c = dotNetBytes[i] & 0xff;
    if (c < 128) {
        result += String.fromCharCode(c);
        i++;
    }
    else if ((c > 191) && (c < 224)) {
        if (i + 1 >= dotNetBytes.length)
            throw "Un-expected encoding error, UTF-8 stream truncated, or incorrect";
        c2 = dotNetBytes[i + 1] & 0xff;
        result += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
        i += 2;
    }
    else {
        if (i + 2 >= dotNetBytes.length || i + 1 >= dotNetBytes.length)
            throw "Un-expected encoding error, UTF-8 stream truncated, or incorrect";
        c2 = dotNetBytes[i + 1] & 0xff;
        c3 = dotNetBytes[i + 2] & 0xff;
        result += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
        i += 3;
    }
}
return result;

}

function encode(stringToEncode, insertBOM = false) {
stringToEncode = stringToEncode.replace(/\r\n/g, “\n”);
var utftext = [];
if (insertBOM == true) {
utftext[0] = 0xef;
utftext[1] = 0xbb;
utftext[2] = 0xbf;
}

for (var n = 0; n < stringToEncode.length; n++) {
    var c = stringToEncode.charCodeAt(n);
    if (c < 128) {
        utftext[utftext.length] = c;
    }
    else if ((c > 127) && (c < 2048)) {
        utftext[utftext.length] = (c >> 6) | 192;
        utftext[utftext.length] = (c & 63) | 128;
    }
    else {
        utftext[utftext.length] = (c >> 12) | 224;
        utftext[utftext.length] = ((c >> 6) & 63) | 128;
        utftext[utftext.length] = (c & 63) | 128;
    }
}
return utftext;

}

协议数据结构需要自定义，与后端商定，自定义协议数据结构

import { ByteArray } from “…/interface/ByteArray”;

export enum CMDID {
CTS_LOGIN_REQ = 1002,
STC_LOGIN_RES = 1003,
}

//协议消息头，占20数组长度
export class MESSAGE_HEAD extends ByteArray {
encode(MsgLen, MsgID, zlibFlag, MsgVer, MsgExtension, UserID, sequenceType, sequenceNo) {
this.writeInt(MsgLen);
this.writeInt(MsgID);
this.writeByte(zlibFlag);
this.writeByte(MsgVer);
this.writeByte(MsgExtension);
this.writeInt(UserID);
this.writeByte(sequenceType);
this.writeInt(sequenceNo);
return this.getbytes();
}
decode() {
let msg: any = {};
msg.MsgLen = this.readInt();
msg.MsgID = this.readInt();
msg.zlibFlag = this.readByte();
msg.MsgVer = this.readByte();
msg.MsgExtension = this.readByte();
msg.UserID = this.readInt();
msg.sequenceType = this.readByte();
msg.sequenceNo = this.readInt();
return msg;
}
}

export class CTS_LOGIN_REQ extends ByteArray {
encode(str) {
let msg: any = {};
msg.info = this.writeString(str);
return this.getbytes();
}

decode() {
    let msg: any = {};
    msg.info = this.readString();
    return msg;
}

}

export class STC_LOGIN_RES extends ByteArray {
encode(str) {
let msg: any = {};
msg.info = this.writeString(str);
return this.getbytes();
}

decode() {
    let msg: any = {};
    msg.info = this.readString();
    return msg;
}

}

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