我可以使用Node.js将文件存储在"内存"中吗？

Question

我正在使用node.js进行一些文件操作工作,我使用的许多软件包都需要发送"路径",以便他们可以打开文件,做一些工作,等等.

但我正在解析数百万个文件,而不是实际将它们存储在磁盘上,我想将它们存储在内存中.这些文件的内容都在我的数据库中,我讨厌将它们写入磁盘,只是为了对它们进行疯狂的工作.

这样的事情可能吗？

Answer 1

看起来有可能看看这篇文章如何创建可写内存流

Answer 2

您可以使用memfs,这是Node.js的内存中文件系统.

Answer 3

也许在从数据库中获取每个文件后创建一个Bufferusing ，然后使用将文件更改为字符串并根据需要解析/操作它let myBuffer = Buffer.from(fetchedData)myBuffer.toString()

Answer 4

如果您使用的是Linux系统，那么您只需通过以下nodejs代码创建您自己的tmpfs（RAM）。这将根据节点代码在 /mnt/myramdisk 创建一个 tmpfs。目录 /mnt/myramdisk 显然必须预先通过 mkdir /mnt/myramdisk 手动创建。

var MountPoint='/mnt/myramdisk';
var TextFile='/MyTextFileInRAM.txt';
var RAM_Size='512m';

const fs = require('fs');

const { exec } = require('child_process');
exec("awk '{print $2}' /proc/mounts | grep "+MountPoint, (err, stdout, stderr) => {
  if (err) {
    // node couldn't execute the command
    //console.log(err);
    console.log(MountPoint+' is Not Mounted yet. Im mounting it now:\n');
    NotMountedYetSoMountIt();
    return;
  }
  // the *entire* stdout and stderr (buffered)
  if(stdout)
    {
        console.log(MountPoint+' is Already Mounted');
        TextToWriteToFileOnTMPFS();
    } 
});

function NotMountedYetSoMountIt()
{
    const { exec } = require('child_process');
    exec('df -h && echo && mount -t tmpfs -o size='+RAM_Size+' tmpfs '+MountPoint+' && echo && df -h', (err, stdout, stderr) => {
      if (err) {
        // node couldn't execute the command
        return;
      }
    // the *entire* stdout and stderr (buffered)
    console.log(`stdout: ${stdout}`);
    TextToWriteToFileOnTMPFS();
    console.log(`stderr: ${stderr}`);
    });
}

function TextToWriteToFileOnTMPFS()
{

    let TextToWrite = 'Hello\n' + 
                      'world @'+CurrentTime();

    fs.writeFile(MountPoint+TextFile, TextToWrite, (err) => {
        // throws an error, you could also catch it here
        if (err) throw err;
        // success case, the file was saved
        console.log('saved!');
    });
}

function addZero(i) {
  if (i < 10) {
    i = "0" + i;
  }
  return i;
}
function CurrentTime()
{
  var d = new Date();
  var h = addZero(d.getHours());
  var m = addZero(d.getMinutes());
  var s = addZero(d.getSeconds());
  return h + ":" + m + ":" + s;
}

输出：

root@box:/daemons#node tmpfs_test.js && cat /mnt/myramdisk/MyTextFileInRAM.txt
/mnt/myramdisk is Not Mounted yet. Im mounting it now:

stdout: Filesystem      Size  Used Avail Use% Mounted on
udev            7.8G     0  7.8G   0% /dev
tmpfs           1.6G  1.4M  1.6G   1% /run
/dev/sda2       938G  436G  454G  49% /
tmpfs           7.8G  449M  7.4G   6% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs           7.8G     0  7.8G   0% /sys/fs/cgroup
/dev/loop1       90M   90M     0 100% /snap/core/8213
/dev/sda1       511M  6.1M  505M   2% /boot/efi
/dev/loop2       90M   90M     0 100% /snap/core/8268


Filesystem      Size  Used Avail Use% Mounted on
udev            7.8G     0  7.8G   0% /dev
tmpfs           1.6G  1.4M  1.6G   1% /run
/dev/sda2       938G  436G  454G  49% /
tmpfs           7.8G  449M  7.4G   6% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs           7.8G     0  7.8G   0% /sys/fs/cgroup
/dev/loop1       90M   90M     0 100% /snap/core/8213
/dev/sda1       511M  6.1M  505M   2% /boot/efi
/dev/loop2       90M   90M     0 100% /snap/core/8268
tmpfs           512M     0  512M   0% /mnt/myramdisk

stderr:
saved!
Hello
world @23:09:15



root@box:/daemons# node tmpfs_test.js && cat /mnt/myramdisk/MyTextFileInRAM.txt
/mnt/myramdisk is Already Mounted
saved!
Hello
world @23:09:19