Uploading a large file has a huge impact on memory

[SoftVision-CiprianMuresan]

[Affected versions]:

• Nightly 56

[Affected Platforms]:

• All Windows
• All Mac
• All Linux

[Steps to reproduce]:

1. Start the Firefox browser and navigate to "https://send.dev.mozaws.net/" page.
2. Upload a large file and open the Task Manager.
3. Sort by Memory and observe the Nightly process.

[Expected result]:

• Low to moderate memory impact.

[Actual results]:

• Memory usage is ~2GB.

[Notes]:

• Here is a Firefox memory profile while the issue is manifesting on Windows:
  memory-report-windows.json.gz
• Mac memory report:
  memory-report-mac.json.gz
• Linux memory report:
  memory-report-linux.json.gz
• Here is a screen recording with the issue:
  

[ghost]

With the way we are processing files this is expected behavior. We are considering looking into chunking/streaming in v2

[pdehaan]

@SoftVision-CiprianMuresan Do you remember how "large" the large file was? 100MB? 1GB?

[SoftVision-PaulOiegas]

@pdehaan almost 2GB. You can see that in the screen recording.

[pdehaan]

Also see #170 (comment), which has an excellent breakdown of different browser behaviors when trying to upload 1-2GB files.

I'll argue that since the behavior leans more towards crashing in certain browsers, we should at least put some note in the UI that sending files over X megabytes may not work as expected, depending on browsers.

Also, maybe we should start an FAQ.md file where we answer some [soon to be] commonly asked questions.

[SoftVision-PaulOiegas]

Agree on that, users should be notified about the behavior/risk.