fc-body
Version:
http-body解析
374 lines (342 loc) • 9.9 kB
JavaScript
/*
* @Author : lovefc
* @Date : 2021-02-22 08:49:39
* @LastEditTime : 2025-04-13 23:00:08
*/
const fs = require('fs');
const path = require('path');
const querystring = require('querystring');
const os = require('os');
const mime = require('mime-types');
/* 切割buffer */
Buffer.prototype.split = Buffer.prototype.split || function (spl) {
let arr = [];
let cur = 0;
let n = 0;
while ((n = this.indexOf(spl, cur)) != -1) {
arr.push(this.slice(cur, n));
cur = n + spl.length;
}
arr.push(this.slice(cur));
return arr;
}
class body {
// 构造函数,开始了
constructor(options) {
let that = this;
this.type = ''; // 限制上传类型
this.mimes = []; // 存储下类型
this.isAutoSaveFile = false; // 是否自动存储文件,设为不存储,那么file_data返回的是该文件的二进制数据,需要自己手动保存
this.savePath = os.tmpdir(); // 上传目录,默认是临时目录
this.minSize = 0; // 最小限制
this.maxSize = 5; // 最大限制
this.errorMsg = {
'TIMEOUT': 'POST超时',
'UNDERSIZE': '数据过小',
'OVERSIZE': '数据过大',
'NOTALLOWEDTYPE': '不允许的类型'
};
// 接受数据结束事件
this.closeEvent = function () {
};
// 这里用了个暴力的方式来覆盖初始配置
for (let key in options) {
if (key in that) {
that[key] = options[key];
}
}
}
// 错误显示
error(err, path) {
let error = {
code: '',
message: '',
path: ''
};
// 很奇怪,err返回的变量竟然是个错误对象
if (Object.prototype.toString.call(err) === "[object Error]") {
error.code = err.code;
error.message = err.toString();
error.path = err.path;
} else if (typeof err === 'string') {
error.code = err;
error.message = this.errorMsg[err];
error.path = path;
}
return error;
}
// 写入文件
writefile(file, body) {
return new Promise((resolve, reject) => {
fs.writeFile(file, body, "binary", function (err) {
if (err) {
reject(err);
}
resolve(true);
});
});
}
// 是否上传文件
isUpfile(request) {
let type = ('content-type' in request.headers) ? request.headers['content-type'] : '';
if (type.match(/boundary=(?:"([^"]+)"|([^;]+))/i)) {
return true;
}
return false;
}
// 是否为get
isGet(request) {
let method = request.method.toLowerCase();
if (method === 'get') {
return true;
}
return false;
}
// 是否为post
isPost(request) {
let method = request.method.toLowerCase();
if (method === 'post') {
return true;
}
return false;
}
// 是否为表单提交
isForm(request) {
let type = ('content-type' in request.headers) ? request.headers['content-type'] : '';
if (type.match(/application\/x-www-form-urlencoded/i)) {
return true;
}
return false;
}
// 是否为raw
isRaw(request) {
let type = ('content-type' in request.headers) ? request.headers['content-type'] : '';
if (type.match(/text\/plain/i)) {
return true;
}
return false;
}
// 是否为json
isJson(request) {
let type = ('content-type' in request.headers) ? request.headers['content-type'] : '';
if (type.match(/application\/json/i)) {
return true;
}
return false;
}
// 获取post数据
getBody(req) {
let that = this;
let request = req;
// 异步操作
return new Promise((resolve, reject) => {
let body = '',
chunks = [],
size = 0;
// 超时
request.on('aborted', function () {
reject(that.error('PTIMEOUT'));
});
// 接受数据
request.on("data", function (postDataChunk) {
chunks.push(postDataChunk); // 为什么要这样?一般使用postDataChunk += postDataChunk,这会把buf转换成string,这就是字符串相加了
size += Buffer.from(postDataChunk).length; // 获取长度
// 判断最小post
if (that.minSize) {
let minLimitNum = that.limitFileSize(that.minSize + 'MB');
if (size < minLimitNum) {
reject(that.error('UNDERSIZE'));
return;
}
}
// 判断最大post
if (that.maxSize) {
let maxLimitNum = that.limitFileSize(that.maxSize + 'MB');
if (size > maxLimitNum) {
reject(that.error('OVERSIZE'));
return;
}
}
});
// 数据接收完毕，执行回调函数
request.on("end", function () {
let buf = Buffer.concat(chunks, size); // 这里为什么要指定size,因为指定size后,计算的会更快一点
if (that.isUpfile(request)) {
try {
body = that.upload(request, buf);
} catch (e) {
reject(e);
}
} else if (that.isPost(request)) {
if (that.isJson(request)) {
body = JSON.parse(buf.toString());
} else if (that.isForm(request)) {
body = querystring.parse(buf.toString());
} else {
body = buf.toString();
}
} else if (that.isRaw(request)) { // 这里其实是txt形式的,所以它返回的也是txt
body = buf.toString();
} else {
body = buf;
}
// 判断,如果为空
if (Buffer.isBuffer(buf) && buf.length == 0) {
body = null;
}
chunks = [];
resolve(body);
});
// 链接关闭
request.on('close', that.closeEvent);
// 出现错误
request.on('error', function (err) {
reject(that.error(err));
});
});
}
// 计算大小格式
limitFileSize(limitSize) {
let arr = ["KB", "MB", "GB"],
limit = limitSize.toUpperCase(),
limitNum = 0;
for (let i = 0; i < arr.length; i++) {
let leval = limit.indexOf(arr[i]);
if (leval > -1) {
limitNum = parseInt(limit.substr(0, leval)) * Math.pow(1024, (i + 1));
break;
}
}
return limitNum;
}
// 生成uuid
UUID(len, radix) {
let chars = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'.split('');
let uuid = [],
i;
radix = radix || chars.length;
if (len) {
for (i = 0; i < len; i++) uuid[i] = chars[0 | Math.random() * radix];
} else {
let r;
uuid[8] = uuid[13] = uuid[18] = uuid[23] = '-';
uuid[14] = '4';
for (i = 0; i < 36; i++) {
if (!uuid[i]) {
r = 0 | Math.random() * 16;
uuid[i] = chars[(i == 19) ? (r & 0x3) | 0x8 : r];
}
}
}
return uuid.join('');
}
async upload(request, postData) {
let file_array = {};
// 这里按照换行符分割
let buffer = Buffer.from(postData);
let _arr = buffer.split('\r\n'); // 这一步很简单,根据\r\n来切割buffer,我并不知道其它的切片是怎么做的,我只是用我的方式,测试过,还不错
let files = [];
let file_data = [];
let start_line = [];
let k = 0;
// 这一步先取出位置
for (let i = 0; i < _arr.length; i++) {
let file = [];
let str = _arr[i].toString(); // 转成字符串来匹配,因为现在是buffer,toString的默认编码是utf8
let match = /Content-Disposition: form-data; (name=""|name="(.+?)")(; filename="(.+?)"|)/i;
let m2 = str.match(match);
if (m2 != null) {
start_line[k] = i;
k++;
file['name'] = m2[2];
if (m2[3]) {
file['name'] = m2[2] ? m2[2] : m2[4];
file['file_name'] = m2[4];
}
}
if (file['name'] || file['file_name']) {
files[i] = file;
}
}
start_line.push(_arr.length - 1);
files = files.filter(d => d);
// 这一步,开始分割body内容
for (let i2 = 0; i2 < files.length; i2++) {
let start = 0,
end = 0,
name2 = files[i2]['name'],
arr = {};
if (typeof (files[i2]['file_name']) != 'undefined') {
start = start_line[i2] + 3;
let str = _arr[start_line[i2] + 1].toString();
let match2 = /Content-Type: ([\s\S]+)/i;
let m3 = str.match(match2);
arr['name'] = files[i2]['file_name'];
if (m3 != null) {
arr['type'] = m3[1];
// 等于-1,说明不存在
let contentType = mime.extension(arr['type']);
if (!contentType) {
throw this.error('NOTALLOWEDTYPE', files[i2]['file_name']);
break;
}
}
} else {
start = start_line[i2] + 2;
}
end = start_line[i2 + 1] - 1;
let buf_list = _arr.slice(start, end);
if (buf_list) {
// 合并buffer数组,很重要的一步哦
let buf_array = [];
let body = Buffer.concat(buf_list);
let size = Buffer.from(body).length; // 获取大小,可避免中文字符串的转换问题
if (typeof (files[i2]['file_name']) != 'undefined') {
buf_list.forEach(function (v, k) {
let buffer1 = Buffer.from(v);
if (k == (buf_list.length - 1)) {
buf_array[k] = buffer1;
} else {
let buffer2 = Buffer.from('\r\n');
buf_array[k] = Buffer.concat([buffer1, buffer2]);
}
});
body = Buffer.concat(buf_array);
arr['size'] = size;
// 判断是否自动保存到临时文件夹
if (this.isAutoSaveFile === true) {
let uuid = this.UUID(10, 16);
let file_name = uuid + '_' + files[i2]['file_name'];
let tmp_file = this.savePath + path.sep + file_name;
arr['tmp_name'] = tmp_file;
try {
await this.writefile(tmp_file, body);
} catch (e) {
throw this.error(e);
}
} else {
arr['data'] = body;
}
} else {
arr = body.toString();
}
// 清掉内存
body = null;
buf_array = null;
}
// 如果有[]符号,这个用来处理多文件
let _name2 = name2.match(/\[\]$/i);
if (_name2) {
if (file_array.hasOwnProperty(name2) === false) {
file_array[name2] = [];
}
file_array[name2].push(arr);
} else {
file_array[name2] = arr;
}
}
files = null;
return file_array;
}
}
module.exports = body;