lib: more cache fixes

[flakey5]

Closes #3806

• Removes CacheStoreReadable and CacheStoreWritable, replaces w/ just Readable and Writable
  • Reasoning: api simplicity
• Renames CacheStoreValue type to CachedResponse
• Removes CacheStore#createReadStream function (see one below on reasoning)
• Adds CacheStore#get function that acts similarly to createReadStream
  • Reasoning: api simplicity & niceness. Returns a GetResult which separates the CacheResponse and Readable for the body
• Simplifies MemoryCacheStore
  • Inline readable & writables
  • readLock and writeLock condensed into just locked that only stops value from being read
• Introduces CacheKey type that we pass into the cache handler, cache stores
  • Replaces us passing in the full request options
  • Reasoning: cache stores don't need the full thing, guides them to be more spec-compliant
• Various internal type fixes
• Fixes regarding a header being present multiple times
  • Stripping headers would result in them being re-encoded in the wrong format
  • Cache control & vary header parsings
• Makes isFull optional
  • Reasoning: some cache stores can't get full / don't have a max. This only exists as a very small optimization
• Removes caching of trailers
  • Reasoning: simplicity sakes, ideally this will be added back later
• Replace deleteByOrigin with deleteByKey
  • Reasoning: The cache handler should not invalidate all requests to an origin #3806
• Adds CachedValue type
  • Separates the body stream and the properties in CachedResponse
  • Allows the stream to be undefined for HEAD requests since there's no body

cc @mcollina @ronag

[ronag]

Can stream be nully? When?

[flakey5]

On HEAD requests

[KhafraDev]

the asserts already catch it

[ronag]

This is broken though like this... onConnect cannot abort the request

[flakey5]

Wdym?

[DTrombett]

Asking here as it seems related, but why is the public directive required? Shouldn't it be required only with authenticated requests?

undici/lib/handler/cache-handler.js

Lines 236 to 243 in 9f467e7

	if (
	!cacheControlDirectives.public ||
	cacheControlDirectives.private === true ||
	cacheControlDirectives['no-cache'] === true ||
	cacheControlDirectives['no-store']
	) {
	return false
	}

[flakey5]

Asking here as it seems related, but why is the public directive required? Shouldn't it be required only with authenticated requests?

Will fix, thanks!

[mcollina]

lgtm