E.openFile failures #7127

espruino-discuss3 · 2025-02-12T17:44:15Z

espruino-discuss3
Feb 12, 2025
Maintainer

Posted at 2019-01-13 by barbiani

Hello everybody,

I am experimenting a bit with the http server (espruino versions from 1.99) and this snippet works most of the time.

First time the page is opened it shows the files in the system as hyperlinks. Downloading a file many times breaks the code.

I´ve found that calling E.openFile many times in the left webide pane makes it fail too. No examples show a close method after openFile, so I believe that it is not needed.

Am I doing it wrong?

>fs.readdir()
=[
  "xx.txt"
 ]
>E.openFile("xx.txt");
=File: {  }
>process.memory()
={ "free": 1857, "usage": 643, "total": 2500, "history": 239,
  "gc": 0, "gctime": 1.839 }
>E.openFile("xx.txt");
=File: {  }
>process.memory()
={ "free": 1592, "usage": 908, "total": 2500, "history": 242,
  "gc": 0, "gctime": 1.669 }
>E.openFile("xx.txt");
=File: {  }
>process.memory()
={ "free": 1327, "usage": 1173, "total": 2500, "history": 242,
  "gc": 0, "gctime": 1.5 }
>E.openFile("xx.txt");
=File: {  }
>process.memory()
={ "free": 1062, "usage": 1438, "total": 2500, "history": 242,
  "gc": 0, "gctime": 1.345 }
>E.openFile("xx.txt");
=File: {  }
>process.memory()
={ "free": 797, "usage": 1703, "total": 2500, "history": 242,
  "gc": 0, "gctime": 1.159 }
>E.openFile("xx.txt");
=File: {  }
>process.memory()
={ "free": 532, "usage": 1968, "total": 2500, "history": 242,
  "gc": 0, "gctime": 0.997 }
>E.openFile("xx.txt");
=File: {  }
>process.memory()
={ "free": 267, "usage": 2233, "total": 2500, "history": 242,
  "gc": 0, "gctime": 0.828 }
>E.openFile("xx.txt");
=undefined
>E.openFile("xx.txt");
=undefined
>

var fs = require("fs");
try {
  fs.readdirSync();
 } catch (e) {
  console.log('Formatting FS - only need to do once');
  E.flashFatFS({ format: true });
  fs.writeFileSync("xx.txt", "..");
}

function onPageRequest(req, res) { 
  var a = url.parse(req.url, true);
  print(a);
  if (a.pathname.substr(-1)=="/") { // a slash at the end, list the directory
    res.writeHead(200, {'Content-Type': 'text/html'});
    res.write("<html><body><p>Contents of "+a.pathname+"</p><ul>");
    fs.readdir().map(function(f) {
      res.write('<a href="'+f+'">'+f+'</a>');
    });
    res.end("</ul></body></html>");
  } else { // No slash, try and open file
    var f = E.openFile(a.pathname, "r");
    if (f !== undefined) { // File open succeeded - send it!
      res.writeHead(200, {'Content-Type': 'text/plain'});
      f.pipe(res); // streams the file to the HTTP response
    } else { // couldn't open file
      res.writeHead(404, {'Content-Type': 'text/plain'});
      res.end("404: Page "+a.pathname+" not found");
    }
  }
}

espruino-discuss3 · 2025-02-12T17:44:17Z

espruino-discuss3
Feb 12, 2025
Maintainer Author

Posted at 2019-01-13 by Robin

Sat 2019.01.12

Performing a Google search, remember Google is your friend,

Google: E.openFile site:espruino.com

http://forum.espruino.com/conversations/327385/

a lengthy discussion and solution was previously proposed

Posted at 2019-01-13 by barbiani

Ha! Thank you. I used the forum search for "openfile" without results ;(

Here is one solution to help other users.

It fixes the heap leak, but still eventually fails to open the file.

    var f = E.openFile(a.pathname, "r");
    if (f !== undefined) { // File open succeeded - send it!
      res.writeHead(200, {'Content-Type': 'text/plain'});
      f.pipe(res, {chunkSize: 512,  complete: f.close});
    } else { // couldn't open file
      res.writeHead(404, {'Content-Type': 'text/plain'});
      res.end("404: Page "+a.pathname+" not found");
    }

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