node_modules/@nd/simple-stream-pkg/index.ts

import * as buffer from 'buffer';
import { EventEmitter } from 'events';
// import * as streampkg from 'stream-pkg';
// import * as profiler from 'v8-profiler';
// import * as fs from 'fs';

const ST_LENGTH = 1;  // state that we should read length
const ST_DATA = 2;  // state that we should read data
const ST_ERROR = 3;  // state that something wrong has happened
export class Composer extends EventEmitter {
    private buf: Buffer;

    private headbuf = new Buffer(2);
    private headoffset = 0;
    private state = ST_LENGTH;
    private dataoffset = 0;
    private buffoffset = 0;
    private end = 0;
    private length = 0;

    private left = 0;

    private hugePackMode = 0;
    private hugePackModeFinished = 0;
    private hugeBuf = Buffer.alloc(0);
    constructor() {
        super();
    }

    public feed(data: Buffer) {

        if (!data) {
            return;
        }

        if (this.state === ST_ERROR) {
            throw new Error('compose in error state, reset it first');
        }

        this.dataoffset = 0;
        this.end = data.length;
        this.length = this.length || 0;

        // data.copy(this._buf, this.offset);

        // this._buf.write(data);
        // Buffer.concat([this._buf, data]);


        while (this.dataoffset < this.end) {

            if (this.state === ST_LENGTH) {

                if (this.headoffset && (this.end - this.dataoffset + this.headoffset) >= 2) {

                    data.copy(this.headbuf, this.headoffset, this.dataoffset, this.dataoffset + 2 - this.headoffset);
                    this.dataoffset += 2 - this.headoffset;
                    this.headoffset = 0;

                    this.left = this.headbuf.readUInt16LE(0);

                    if (this.hugePackMode && this.left < 32701) {
                        this.hugePackModeFinished = 1;
                        this.hugePackMode = 0;
                    }

                    if (this.left > 32700) {
                        this.left = 32700;
                        this.hugePackMode = 1;
                        this.hugePackModeFinished = 0;
                        if (!this.hugeBuf) {
                            this.hugeBuf = Buffer.alloc(0);
                        }
                    }
                    this.state = ST_DATA;
                    this.buf = new Buffer(this.left);
                } else {
                    if (this.end - this.dataoffset >= 2) {
                        this.left = data.readUInt16LE(this.dataoffset);
                        if (this.hugePackMode && this.left < 32701) {
                            this.hugePackModeFinished = 1;
                            this.hugePackMode = 0;
                        }

                        if (this.left > 32700) {
                            this.left = 32700;
                            this.hugePackMode = 1;
                            this.hugePackModeFinished = 0;
                            if (!this.hugeBuf) {
                                this.hugeBuf = Buffer.alloc(0);
                            }
                        }
                        this.state = ST_DATA;
                        this.dataoffset = this.dataoffset + 2;
                        this.buf = new Buffer(this.left);
                    } else {
                        data.copy(this.headbuf, 0, this.dataoffset, this.end);
                        this.headoffset = this.end - this.dataoffset;
                        this.dataoffset += this.headoffset;

                    }
                }


            }

            if (this.state === ST_DATA) {
                let length = Math.min(this.left, data.length - this.dataoffset);
                data.copy(this.buf, this.buf.length - this.left, this.dataoffset, this.dataoffset + length);
                this.left -= length;
                this.dataoffset += length;

                if ((this.hugePackMode || this.hugePackModeFinished) && this.left === 0) {
                    if (this.hugePackModeFinished === 0) {
                        this.hugeBuf = Buffer.concat([this.hugeBuf, this.buf]);
                        this.left = 0;
                        this.state = ST_LENGTH;
                        delete this.buf;
                    }

                    if (this.hugePackModeFinished === 1) {
                        this.hugeBuf = Buffer.concat([this.hugeBuf, this.buf]);
                        this.emit('data', this.hugeBuf);
                        this.hugePackModeFinished = 0;
                        this.hugePackMode = 0;
                        this.left = 0;
                        this.state = ST_LENGTH;
                        delete this.buf;
                        delete this.hugeBuf;
                    }

                } else {

                    if (this.left === 0) {
                        this.emit('data', this.buf);
                        this.left = 0;
                        this.state = ST_LENGTH;
                        delete this.buf;
                    }
                }


                // return;
            }

            if (this.state === ST_ERROR) {
                break;
            }
        }

    }

    public compose(data: string) {


        if (data.length === 0) {
            throw new Error('data should not be empty.');
        }
        let d = Buffer.from(data);

        let totalLength = d.length;
        let offset = 0;

        let buf = new Buffer(d.length + 2 * (Math.floor(totalLength / 32700) + 1));
        let loop = 0;
        while (totalLength !== 0) {
            let writelength = totalLength;
            let currentLength = totalLength;
            if (writelength > 32700) {
                writelength = 32701;
                currentLength = 32700;
            }

            buf.writeUInt16LE(writelength, offset + 2 * (loop));
            d.copy(buf, 2 * (loop + 1) + offset, offset, offset + currentLength);
            offset = offset + currentLength;
            totalLength = totalLength - currentLength;
            loop = loop + 1;
        }


        return buf;

    }
}
// profiler.startProfiling();
// let comp = new Compose();

// let buf = comp.compose(JSON.stringify({
//     'id': 10,
//     'msg': {
//         'namespace': 'user', 'serverType': 'test', 'service': 'service', 'method': 'echo',
//         'args': [{ 'index': 9, 'time': 1498919947021 }],
//     },
// }));

// console.time('1');
// for (let i = 0; i < 1; i++) {
//     comp.compose('你好世界');
// }

// console.timeEnd('1');

// comp.on('data', (d: Buffer) => {
//     let s = JSON.parse(d.toString());

//     console.log(s);
// });

// console.time('1');
// for (let i = 0; i < 100; i++) {
//     buf = comp.compose(JSON.stringify({
//         'id': 10,
//         'msg': {
//             'namespace': 'user', 'serverType': 'test', 'service': 'service', 'method': 'echo',
//             'args': [{ 'index': 9, 'time': 1498919947021 }],
//         },
//     }));
//     comp.feed(buf);
//     comp.feed(buf.slice(0, 5));
//     comp.feed(buf.slice(5, buf.length));
// }
// console.timeEnd('1');

// let sp = new streampkg();
// buf = sp.compose('你好世界');
// console.time('1');
// for (let i = 0; i < 1000000; i++) {
//     sp.compose('你好世界');
// }

// console.timeEnd('1');
// sp.on('data', (d) => {
//     // let s = d.toString();
//     //console.log(s);
// });
// console.time('1');
// for (let i = 0; i < 1000000; i++) {
//     sp.feed(buf);
//     sp.feed(buf.slice(0, 5));
//     sp.feed(buf.slice(5, buf.length));
// }
// console.timeEnd('1');

// profiler.stopProfiling().export((error, result) => {
//     fs.writeFileSync('client.cpuprofile', result);
//     console.log('clientside profile saved');
// });