more than one renderer create leveldb error

[milu2003]

Hello, I recently used leveldb in electron.

I saw you were create leveldb in renderer.

If more than one renderer this will be a problem。

Do you have any solutions？

[cosmosgenius]

Two ways to solve this:

• By opening leveldb in the main and use ipc to access leveldb in renderer.
• Open and close leveldb before and after every operation respectively.

This was a test project to demonstrate electron-userland/electron-builder#647.

Probably I'll update the project to open leveldb in main.

[milu2003]

i just try opening in main. But there is a problem

use it in renderer:

`var rs = testdb.createReadStream(this.valueOps)

testdb.open();

rs.on('data' , function (data) {
   console.log(data.key, '=', data.value)

})
rs.on('error', function (err) {
    dlog(err);
})
rs.on('close', function () {
    dlog('关闭');
})
rs.on('end', function () {
    dlog('结束');
});
`

He did not execute the end callback

see my other issues:
Level/levelup#404

Although I closed the issues, but later found that there will still be a problem

You can test it on your project

[milu2003]

I just close and open database when I was created.

Open and close leveldb before and after every operation respectively.

Maybe in accordance with what you said, each operation is closed open may be able to solve the problem

But is the price too high? Performance is very affected by it?