* adds middleware for rate limiting
* added comment for InMemoryStore ShouldAllow
* removed redundant mutex declaration
* fixed lint issues
* removed sleep from tests
* improved coverage
* refactor: renames Identifiers, includes default SourceFunc
* Added last seen stats for visitor
* uses http Constants for improved readdability
adds default error handler
* used other handler apart from default handler to mark custom error handler for rate limiting
* split tests into separate blocks
added an error pair to IdentifierExtractor
Includes deny handler for explicitly denying requests
* adds comments for exported members Extractor and ErrorHandler
* makes cleanup implementation inhouse
* Avoid race for cleanup due to non-atomic access to store.expiresIn
* Use a dedicated producer for rate testing
* tidy commit
* refactors tests, implicitly tests lastSeen property on visitor
switches NewRateLimiterMemoryStore constructor to Referential Functions style (Advised by @pafuent)
* switches to mock of time module for time based tests
tests are now fully deterministic
* improved coverage
* replaces Rob Pike referential options with more conventional struct configs
makes cleanup asynchronous
* blocks racy access to lastCleanup
* Add benchmark tests for rate limiter
* Add rate limiter with sharded memory store
* Racy access to store.lastCleanup eliminated
Merges in shiny sharded map implementation by @lammel
* Remove RateLimiterShradedMemoryStore for now
* Make fields for RateLimiterStoreConfig public for external configuration
* Improve docs for RateLimiter usage
* Fix ErrorHandler vs. DenyHandler usage for rate limiter
* Simplify NewRateLimiterMemoryStore
* improved coverage
* updated errorHandler and denyHandler to use echo.HTTPError
* Improve wording for error and comments
* Remove duplicate lastSeen marking for Allow
* Improve wording for comments
* Add disclaimer on perf characteristics of memory store
* changes Allow signature on rate limiter to return err too
Co-authored-by: Roland Lammel <rl@neotel.at>