core.cache is a Clojure contrib library providing the following features:
-
An underlying
CacheProtocol
used as the base abstraction for implementing new synchronous caches -
A
defcache
macro for hooking yourCacheProtocol
implementations into the Clojure associative data capabilities. -
Implementations of some basic caching strategies
- First-in-first-out (FIFOCache)
- Least-recently-used (LRUCache)
- Least-used (LUCache -- sometimes called Least Frequently Used)
- Time-to-live (TTLCacheQ)
- Naive cache (BasicCache)
- Naive cache backed with soft references (SoftCache)
-
Implementation of an efficient buffer replacement policy based on the low inter-reference recency set algorithm (LIRSCache) described in the LIRS paper
-
Factory functions for each existing cache type
-
Caches are generally immutable and should be used in conjunction with Clojure's state management, such as
atom
. SoftCache is the exception here, built on top of mutable Java collections, but it can be treated as an immutable cache as well.
core.cache is based on an old library named Clache that has been thoroughly deprecated.
Latest stable release: 0.7.1
Leiningen dependency information:
[org.clojure/core.cache "0.7.1"]
Maven dependency information:
<dependency>
<groupId>org.clojure</groupId>
<artifactId>core.cache</artifactId>
<version>0.7.1</version>
</dependency>
(require '[clojure.core.cache :as cache])
(def C1 (cache/fifo-cache-factory {:a 1, :b 2}))
(def C1' (if (cache/has? C1 :c)
(cache/hit C1 :c)
(cache/miss C1 :c 42)))
;=> {:a 1, :b 2, :c 42}
(cache/lookup C1' :c)
;=> 42
(get C1' :c) ; cache/lookup is implemented as get
;=> 42
;; a shorthand for the above conditional...
(def C1' (cache/through-cache C1 :c (constantly 42)))
;; ...which uses a value to compute the result from the key...
(cache/through-cache C1 my-key (partial jdbc/get-by-id db-spec :storage))
;; ...so you could fetch values from a database if they're not in cache...
(cache/evict C1 :b)
;=> {:a 1}
;; since the caches are immutable, you would normally wrap them in an atom
(def C2 (atom (cache/fifo-cache-factory {:a 1, :b 2})))
(swap! C2 cache/through-cache :d (constantly 13))
;=> {:a 1, :b 3, :d 13}
(swap! C2 cache/evict :b)
;=> {:a 1, :d}
(get @C2 :a)
;=> 1
Refer to docstrings in the clojure.core.cache
namespace, or the autogenerated API documentation for additional documentation
- Release 0.7.1 on 2018.03.02
- CCACHE-49 Fix TTLCacheQ
seed
function and expand tests on TTLCacheQ
- CCACHE-49 Fix TTLCacheQ
- Release 0.7.0 on 2018.03.01
- CCACHE-46 Fix TTLCache when wrapped around another cache (Ivan Kryvoruchko)
- CCACHE-43 Add
through-cache
to provide a version ofthrough
that plays nice withswap!
etc - CCACHE-40 Fix FIFOCache stack overflow on large threshold (uses PersistentQueue now instead of concat and list)
- CCACHE-39 Fix FIFOCache evict/miss queue handling
- CCACHE-20 Updated README to clarify that caches are immutable and provide examples of use with
atom
etc - CCACHE-15 Added queue and generation logic to reduce
miss
cost and makeevict
O(1); rename TTLCache -> TTLCacheQ (Kevin Downey) - Drop support for Clojure 1.3/1.4/1.5
- Release 0.6.5 on 2016.03.28
- Release 0.6.4 on 2014.08.06
- Thanks to Paul Stadig and Nicola Mometto who contributed patches for this release
- CCACHE-34 bump tools.priority-map dependency to 0.0.4
- CCACHE-28 concurrency bug in has? for SoftCache
- CCACHE-29 fix conj implementation for caches
- CCACHE-30 make-reference need not be dynamic
- CCACHE-26 hit function in LRU cache can give funny results
- Release 0.6.3 on 2013.03.15
- Added through to encapsulate check logic
- Release 0.6.2 on 2012.08.07 more information
- Removed reflection warnings
- Fixed eviction of items from LU, TTL and LRU caches with thresholds less than two
- Fixed eviction of items from FIFO cache prior to threshold
- Release 0.6.2 on 2012.07.13 more information
- Added SoftCache
- Fixed eviction of items from LU and LRU caches prior to threshold
- Adjusted default thresholds in factory functions
- Release 0.5.0 on 2011.12.13 more information
- Added
evict
- Added cache factory functions
- Added associatve operation support
- Added
Copyright (c) Rich Hickey, Michael Fogus and contributors, 2012. All rights reserved. The use and distribution terms for this software are covered by the Eclipse Public License 1.0 (http://opensource.org/licenses/eclipse-1.0.php) which can be found in the file epl-v10.html at the root of this distribution. By using this software in any fashion, you are agreeing to be bound bythe terms of this license. You must not remove this notice, or any other, from this software.