pax_global_header 0000666 0000000 0000000 00000000064 13700665644 0014525 g ustar 00root root 0000000 0000000 52 comment=bcb54d096f2303ce80960e125b5991ac4d6325c3 ristretto-0.0.3/ 0000775 0000000 0000000 00000000000 13700665644 0013564 5 ustar 00root root 0000000 0000000 ristretto-0.0.3/.deepsource.toml 0000664 0000000 0000000 00000000275 13700665644 0016701 0 ustar 00root root 0000000 0000000 version = 1 test_patterns = [ '**/*_test.go' ] exclude_patterns = [ ] [[analyzers]] name = 'go' enabled = true [analyzers.meta] import_path = 'github.com/dgraph-io/ristretto' ristretto-0.0.3/.github/ 0000775 0000000 0000000 00000000000 13700665644 0015124 5 ustar 00root root 0000000 0000000 ristretto-0.0.3/.github/CODEOWNERS 0000664 0000000 0000000 00000000325 13700665644 0016517 0 ustar 00root root 0000000 0000000 # CODEOWNERS info: https://help.github.com/en/articles/about-code-owners # Owners are automatically requested for review for PRs that changes code # that they own. * @manishrjain @karlmcguire @martinmr @anurags92 ristretto-0.0.3/.travis.yml 0000664 0000000 0000000 00000000203 13700665644 0015670 0 ustar 00root root 0000000 0000000 language: go go: - 1.12 - 1.13 env: - GO111MODULE=on # Enable go module for all versions. script: - go test -race ./... ristretto-0.0.3/CHANGELOG.md 0000664 0000000 0000000 00000002664 13700665644 0015405 0 ustar 00root root 0000000 0000000 # Changelog All notable changes to this project will be documented in this file. The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/) and this project will adhere to [Semantic Versioning](http://semver.org/spec/v2.0.0.html) starting v1.0.0. ## Unreleased ### Changed ### Added ### Fixed ## [0.0.3] - 2020-07-06 [0.0.3]: https://github.com/dgraph-io/ristretto/compare/v0.0.2..v0.0.3 ### Changed ### Added ### Fixed - z: use MemHashString and xxhash.Sum64String ([#153][]) - Check conflict key before updating expiration map. ([#154][]) - Fix race condition in Cache.Clear ([#133][]) - Improve handling of updated items ([#168][]) - Fix droppedSets count while updating the item ([#171][]) ## [0.0.2] - 2020-02-24 [0.0.2]: https://github.com/dgraph-io/ristretto/compare/v0.0.1..v0.0.2 ### Added - Sets with TTL. ([#122][]) ### Fixed - Fix the way metrics are handled for deletions. ([#111][]) - Support nil `*Cache` values in `Clear` and `Close`. ([#119][]) - Delete item immediately. ([#113][]) - Remove key from policy after TTL eviction. ([#130][]) [#111]: https://github.com/dgraph-io/ristretto/issues/111 [#113]: https://github.com/dgraph-io/ristretto/issues/113 [#119]: https://github.com/dgraph-io/ristretto/issues/119 [#122]: https://github.com/dgraph-io/ristretto/issues/122 [#130]: https://github.com/dgraph-io/ristretto/issues/130 ## 0.0.1 First release. Basic cache functionality based on a LFU policy. ristretto-0.0.3/LICENSE 0000664 0000000 0000000 00000023675 13700665644 0014606 0 ustar 00root root 0000000 0000000 Apache License Version 2.0, January 2004 http://www.apache.org/licenses/ TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 1. Definitions. "License" shall mean the terms and conditions for use, reproduction, and distribution as defined by Sections 1 through 9 of this document. "Licensor" shall mean the copyright owner or entity authorized by the copyright owner that is granting the License. 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END OF TERMS AND CONDITIONS ristretto-0.0.3/README.md 0000664 0000000 0000000 00000020354 13700665644 0015047 0 ustar 00root root 0000000 0000000 # Ristretto [](http://godoc.org/github.com/dgraph-io/ristretto) [](https://goreportcard.com/report/github.com/dgraph-io/ristretto) [](https://gocover.io/github.com/dgraph-io/ristretto)  Ristretto is a fast, concurrent cache library built with a focus on performance and correctness. The motivation to build Ristretto comes from the need for a contention-free cache in [Dgraph][]. [Dgraph]: https://github.com/dgraph-io/dgraph ## Features * **High Hit Ratios** - with our unique admission/eviction policy pairing, Ristretto's performance is best in class. * **Eviction: SampledLFU** - on par with exact LRU and better performance on Search and Database traces. * **Admission: TinyLFU** - extra performance with little memory overhead (12 bits per counter). * **Fast Throughput** - we use a variety of techniques for managing contention and the result is excellent throughput. * **Cost-Based Eviction** - any large new item deemed valuable can evict multiple smaller items (cost could be anything). * **Fully Concurrent** - you can use as many goroutines as you want with little throughput degradation. * **Metrics** - optional performance metrics for throughput, hit ratios, and other stats. * **Simple API** - just figure out your ideal `Config` values and you're off and running. ## Status Ristretto is usable but still under active development. We expect it to be production ready in the near future. ## Table of Contents * [Usage](#Usage) * [Example](#Example) * [Config](#Config) * [NumCounters](#Config) * [MaxCost](#Config) * [BufferItems](#Config) * [Metrics](#Config) * [OnEvict](#Config) * [KeyToHash](#Config) * [Cost](#Config) * [Benchmarks](#Benchmarks) * [Hit Ratios](#Hit-Ratios) * [Search](#Search) * [Database](#Database) * [Looping](#Looping) * [CODASYL](#CODASYL) * [Throughput](#Throughput) * [Mixed](#Mixed) * [Read](#Read) * [Write](#Write) * [FAQ](#FAQ) ## Usage ### Example ```go func main() { cache, err := ristretto.NewCache(&ristretto.Config{ NumCounters: 1e7, // number of keys to track frequency of (10M). MaxCost: 1 << 30, // maximum cost of cache (1GB). BufferItems: 64, // number of keys per Get buffer. }) if err != nil { panic(err) } // set a value with a cost of 1 cache.Set("key", "value", 1) // wait for value to pass through buffers time.Sleep(10 * time.Millisecond) value, found := cache.Get("key") if !found { panic("missing value") } fmt.Println(value) cache.Del("key") } ``` ### Config The `Config` struct is passed to `NewCache` when creating Ristretto instances (see the example above). **NumCounters** `int64` NumCounters is the number of 4-bit access counters to keep for admission and eviction. We've seen good performance in setting this to 10x the number of items you expect to keep in the cache when full. For example, if you expect each item to have a cost of 1 and MaxCost is 100, set NumCounters to 1,000. Or, if you use variable cost values but expect the cache to hold around 10,000 items when full, set NumCounters to 100,000. The important thing is the *number of unique items* in the full cache, not necessarily the MaxCost value. **MaxCost** `int64` MaxCost is how eviction decisions are made. For example, if MaxCost is 100 and a new item with a cost of 1 increases total cache cost to 101, 1 item will be evicted. MaxCost can also be used to denote the max size in bytes. For example, if MaxCost is 1,000,000 (1MB) and the cache is full with 1,000 1KB items, a new item (that's accepted) would cause 5 1KB items to be evicted. MaxCost could be anything as long as it matches how you're using the cost values when calling Set. **BufferItems** `int64` BufferItems is the size of the Get buffers. The best value we've found for this is 64. If for some reason you see Get performance decreasing with lots of contention (you shouldn't), try increasing this value in increments of 64. This is a fine-tuning mechanism and you probably won't have to touch this. **Metrics** `bool` Metrics is true when you want real-time logging of a variety of stats. The reason this is a Config flag is because there's a 10% throughput performance overhead. **OnEvict** `func(hashes [2]uint64, value interface{}, cost int64)` OnEvict is called for every eviction. **KeyToHash** `func(key interface{}) [2]uint64` KeyToHash is the hashing algorithm used for every key. If this is nil, Ristretto has a variety of [defaults depending on the underlying interface type](https://github.com/dgraph-io/ristretto/blob/master/z/z.go#L19-L41). Note that if you want 128bit hashes you should use the full `[2]uint64`, otherwise just fill the `uint64` at the `0` position and it will behave like any 64bit hash. **Cost** `func(value interface{}) int64` Cost is an optional function you can pass to the Config in order to evaluate item cost at runtime, and only for the Set calls that aren't dropped (this is useful if calculating item cost is particularly expensive and you don't want to waste time on items that will be dropped anyways). To signal to Ristretto that you'd like to use this Cost function: 1. Set the Cost field to a non-nil function. 2. When calling Set for new items or item updates, use a `cost` of 0. ## Benchmarks The benchmarks can be found in https://github.com/dgraph-io/benchmarks/tree/master/cachebench/ristretto. ### Hit Ratios #### Search This trace is described as "disk read accesses initiated by a large commercial search engine in response to various web search requests."