Node流操作

Posted 2020-11-21 comedy

tags:

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详情：

https://www.cnblogs.com/lalalagq/p/9749680.html

流：读取流，写入流，双向读写流。

读写流——压缩、加密

数据库不能直接接受流

sf.readFile(‘www${pathname}‘,(err,buffer)=>{
 res.write(buffer);
});
1.占用内存；
2.资源使用不均匀


const fs = require(‘fs);
let rs =  fs.createReadStream(‘1.txt‘);
let ws = fs.createWriteStream(‘2.txt‘);

rs.pipe(ws);

rs.on(‘error‘,()=>){
 console.log(err);
})

ws.on(‘finish‘,()=>{
 console.log(‘完成‘);
})

Comedy:
读写流——压缩、加密
数据库不能直接接受流

const fs = require(‘fs);
const zilib = require(‘zlib‘);

let rs =  fs.createReadStream(‘1.txt‘);
let gz = zlib.createGzip();
let ws = fs.createWriteStream(‘2.txt.gz‘);

rs.pipe(gz).pipe(ws);

rs.on(‘error‘,()=>){
 console.log(err);
})

ws.on(‘finish‘,()=>{
 console.log(‘完成‘);
})

Comedy:
cosnt http = require(‘http‘);
const zlib = require(‘zlib‘);
const url = require(‘url‘);
const fs = require(‘fs‘);

http.createSever((req,res)=>{
 let {pathname} = url.parse(req.url,true);
let filepath=‘www‘+pathname;

 
fs.stat(filepath,(err,stat)=>{
if(err){
 //res.setHerader(‘content-encoding‘,‘deflate‘);
  res.writeHeader(404);
  res.write(‘NOT FOUND‘);
  res.end();
}else{
 let rs=fs.createReadStream(filepath);
 rs.on(‘error‘,()=>{ });
 res.setHerader(‘content-encoding‘,‘gzip‘);
 let gz = zlib.createGzip();
 rs.pipe(res);

}
});

}).listen(8520);