Add test and improve performance

[tinchoz49]

The recently support for chrome 81 decrease the performance since we have to get on every read/write an updated entry.file: #3

This PR improve that:

• The write process only use the size prop of the file, something that we can get updated on every write request and just use that information instead of getting a new entry file.

• The read process is different, it needs the updated file, so every time that we write into the file we marked to update. With this approach only when the file was really updated it would try to get a new entry file.

current version

10000 tiny writes: 10936.55419921875ms
10000 tiny reads: 10997.553955078125ms
512mb write: 19099.5107421875ms
512mb read: 18458.8701171875ms

PR version

10000 tiny writes: 5605.403076171875ms
10000 tiny reads: 6444.77099609375ms
512mb write: 13663.65771484375ms
512mb read: 6499.1806640625ms

[mafintosh]

i didn't realise we had this! should we publish that to npm?

[tinchoz49]

I noticed the same. We should, I think is really helpful to test these modules.

[mafintosh]

published

[arj03]

These changes looks great @tinchoz49. Anything I can do to move this forward?

[tinchoz49]

Hey @arj03 thanks :).

We are testing this PR in our application and trying to get stability. It seems working but we are having a race condition issue and we need to check if it belongs to this PR or not. After that I will put into review next week.

[arj03]

Been testing this, not sure about the speed diff, but at least I didn't get any errors from manual testing with this new code.

[arj03]

On further testing I'm getting a few of these: Could not satisfy length