Bugfix/cannot save file with long URL key

[attila-at-hyper]

If you want to store an image (using Imaginary) in the disk storage and use the file’s remote URL as key, saving will fail if the URL is long. This PR tries to fix the issue by using the URL’s MD5 digest as file name instead of the Base64 encoded version of the URL

[vadymmarkov]

We could reconsider the source of MD5 generation later and go wth this library to fix the current bug. What do you think @zenangst ?

[zenangst]

That works

[vadymmarkov]

I think tests are broken now. It needs to be updated with this change.

[attila-at-hyper]

@vadymmarkov tests fail because the MD5 pod is not installed by Travis. I've added the MD5 dependency to the podspec and recently tried to add it to a new Carthage file, but none of those helped. Any hints? Sorry, I'm not fluent in Travis... cc @zenangst

[vadymmarkov]

Have you tried to run test @attila-at-hyper ? Because we have this one that needs to be changed I believe https://github.com/hyperoslo/Cache/blob/master/Tests/iOS/Specs/Storage/DiskStorageSpec.swift#L181

I'm not sure that MD5 is available via Carthage and it might be a problem. If it's a case it's better to use https://github.com/krzyzanowskim/CryptoSwift instead.

[attila-at-hyper]

@vadymmarkov: I've switched to CryptoSwift since MD5 is indeed not available via Carthage. Local build seems to be working fine and I'm currently waiting for Travis to complete its run to see if it builds well there, too.

I'm having some issues with running the tests though: after hitting Cmd-U tests are seemingly built and fail (as expected), however when I try to check which tests have failed, I see no tests at all (see below). Please advise. Once I have the tests up and running, I'll fix the mentioned test.

[attila-at-hyper]

@vadymmarkov: I think I've found the reason for the test failure. Working on it.

[attila-at-hyper]

@vadymmarkov problem found and fixed. Tests now work fine locally. Waiting for Travis... Mac build currently fails because for some reason the compiler can't find the CryptoSwift module. Is that a killer issue for now?

[attila-at-hyper]

@vadymmarkov: never mind, I've managed to fix the Mac test, too. Waiting for Travis to complete.

[vadymmarkov]

@attila-at-hyper All tests have passed. Great work @attila-at-hyper, gonna merge it!

[zenangst]

Should we make a new release?

[attila-at-hyper]

@zenangst: yeah, I think that would make sense. This change does make a difference for Imaginary.

[onmyway133]

I've made CommonCrypto wrapper https://github.com/onmyway133/CommonCrypto.swift in case CryptoSwift is overkill 😄 . It works now 😬

[onmyway133]

@vadymmarkov @zenangst updated again 😄 You may want to take a look https://github.com/onmyway133/SwiftHash

[vadymmarkov]

@onmyway133 Feel free to make a PR with your new library 😉