Include the query in the cache ID

[tikkss]

GitHub: follow-up GH-24

Because if URL has any query parameters, the cache ID may be conflicted.
The query is now included in the cache ID:

• URL: https://example.com/file?a=b
  • => cache ID: example.com+a=b
• URL: https://example.com/file?a=c
  • => cache ID: example.com+a=c

So clear_cache doesn't remove caches for other queries.

The cache ID keeps only the following characters and replaces all other
characters with -:

• The URL unreserved characters A-Z a-z 0-9 - . _ ~ (RFC 3986 2.3)
• = for query readability

See also:

• RFC 3986 "Uniform Resource Identifier (URI): Generic Syntax":
  https://www.rfc-editor.org/rfc/rfc3986
• "Naming Files, Paths, and Namespaces" (Microsoft Learn):
  https://learn.microsoft.com/en-us/windows/win32/fileio/naming-a-file

[kou]

How about using Digest::SHA256.hexdigest instead of escaping special characters?
Or how about using allow list style instead of deny list style? I feel that deny list style is difficult to maintain...

[tikkss]

Thanks for your suggestion!

I like the allow list style! I've implemented it at bf0f9ab.
I don't like digest style because we can't find the source URL from a cache ID when we debug.

I've updated the PR description. Could you review it again?

[kou]

It seems that example.com/a/b?c=d and example.com/a/b-c=d become the same cache ID.

Can we avoid it? Or we don't need to care about the case...?

[tikkss]

Thanks for your finding it!

I've changed the query separator from - to + at 0fe7cc5.
+ isn't in the allow list so does not become the same cache ID:

• example.com/a/b?c=d
  • example.com-a-b+c=d
• example.com/a/b-c=d
  • example.com-a-b-c=d

I've also updated the PR description.

[kou]

Thanks.

[tikkss]

Thanks for your review!