util::ResponseExpirationCache Class Reference

Cache of requests' responses with TTL support and configurable cachable commands. More...

#include <ResponseExpirationCache.hpp>

Classes
struct	EntryData
	A data structure to store a cache entry with its timestamp. More...
struct	Error
	A data structure to represent errors that can occur during an update of the cache. More...

Public Types
using	CacheEntry = util::BlockingCache<EntryData, Error>
using	Updater = CacheEntry::Updater
using	Verifier = CacheEntry::Verifier

Public Member Functions
	ResponseExpirationCache (std::chrono::steady_clock::duration cacheTimeout, std::unordered_set< std::string > const &cmds)
	Construct a new ResponseExpirationCache object.
bool	shouldCache (std::string const &cmd)
	Check if the given command should be cached.
std::expected< boost::json::object, Error >	getOrUpdate (boost::asio::yield_context yield, std::string const &cmd, Updater updater, Verifier verifier)
	Get a cached response or update the cache if necessary.
void	invalidate ()
	Invalidate all entries in the cache.

Detailed Description

Cache of requests' responses with TTL support and configurable cachable commands.

This class implements a time-based expiration cache for RPC responses. It allows caching responses for specified commands and automatically invalidates them after a configured timeout period. The cache uses BlockingCache internally to handle concurrent access and updates.

Constructor & Destructor Documentation

ResponseExpirationCache()

util::ResponseExpirationCache::ResponseExpirationCache	(	std::chrono::steady_clock::duration	cacheTimeout,
		std::unordered_set< std::string > const &	cmds )

Construct a new ResponseExpirationCache object.

Parameters

cacheTimeout	The time period after which cached entries expire
cmds	The commands that should be cached (requests for other commands won't be cached)

Member Function Documentation

getOrUpdate()

std::expected< boost::json::object, ResponseExpirationCache::Error > util::ResponseExpirationCache::getOrUpdate ( boost::asio::yield_context yield, std::string const & cmd, Updater updater, Verifier verifier )

nodiscard

Get a cached response or update the cache if necessary.

This method returns a cached response if it exists and hasn't expired. If the cache entry is expired or doesn't exist, it calls the updater to generate a new value. If multiple coroutines request the same entry simultaneously, only one updater will be called while others wait.

Note

cmd must be one of the commands that are cached. There is an ASSERT() inside the function

Parameters

yield	Asio yield context for coroutine suspension
cmd	The command to get the response for
updater	Function to generate the response if not in cache or expired
verifier	Function to validate if a response should be cached

Returns

The cached or newly generated response, or an error

invalidate()

void util::ResponseExpirationCache::invalidate

(

)

Invalidate all entries in the cache.

This causes all cached entries to be cleared, forcing the next access to generate new responses.

shouldCache()

bool util::ResponseExpirationCache::shouldCache

(

std::string const &

cmd

)

Check if the given command should be cached.

Parameters

cmd	The command to check

Returns

true if the command should be cached, false otherwise

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The documentation for this class was generated from the following files:

• /__w/clio/clio/src/util/ResponseExpirationCache.hpp
• /__w/clio/clio/src/util/ResponseExpirationCache.cpp