pax_global_header00006660000000000000000000000064145055777160014533gustar00rootroot0000000000000052 comment=97f49b45d00745bd1bbc7a64d9363e5edf216713 golang-lru-arc-v2.0.7/000077500000000000000000000000001450557771600145415ustar00rootroot00000000000000golang-lru-arc-v2.0.7/.github/000077500000000000000000000000001450557771600161015ustar00rootroot00000000000000golang-lru-arc-v2.0.7/.github/workflows/000077500000000000000000000000001450557771600201365ustar00rootroot00000000000000golang-lru-arc-v2.0.7/.github/workflows/ci.yml000066400000000000000000000021541450557771600212560ustar00rootroot00000000000000name: build on: push: branches: tags: pull_request: jobs: build: runs-on: ubuntu-latest steps: - name: set up go 1.19 uses: actions/setup-go@6edd4406fa81c3da01a34fa6f6343087c207a568 # v3.5.0 with: go-version: 1.19 id: go - name: checkout uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0 - name: build and test run: | go test -timeout=60s -race ./... go build -race ./... - name: build and test ARC working-directory: ./arc run: | go test -timeout=60s -race go build -race - name: install golangci-lint run: curl -sfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh| sh -s -- -b $GITHUB_WORKSPACE v1.53.3 - name: run golangci-lint run: $GITHUB_WORKSPACE/golangci-lint run --out-format=github-actions ./... ./simplelru/... ./expirable/... - name: run golangci-lint on ARC working-directory: ./arc run: $GITHUB_WORKSPACE/golangci-lint run --out-format=github-actions ./... golang-lru-arc-v2.0.7/.gitignore000066400000000000000000000004031450557771600165260ustar00rootroot00000000000000# Compiled Object files, Static and Dynamic libs (Shared Objects) *.o *.a *.so # Folders _obj _test # Architecture specific extensions/prefixes *.[568vq] [568vq].out *.cgo1.go *.cgo2.c _cgo_defun.c _cgo_gotypes.go _cgo_export.* _testmain.go *.exe *.test golang-lru-arc-v2.0.7/.golangci.yml000066400000000000000000000015221450557771600171250ustar00rootroot00000000000000# Copyright (c) HashiCorp, Inc. # SPDX-License-Identifier: MPL-2.0 linters: fast: false disable-all: true enable: - revive - megacheck - govet - unconvert - gas - gocyclo - dupl - misspell - unparam - unused - typecheck - ineffassign # - stylecheck - exportloopref - gocritic - nakedret - gosimple - prealloc # golangci-lint configuration file linters-settings: revive: ignore-generated-header: true severity: warning rules: - name: package-comments severity: warning disabled: true - name: exported severity: warning disabled: false arguments: ["checkPrivateReceivers", "disableStutteringCheck"] issues: exclude-use-default: false exclude-rules: - path: _test\.go linters: - dupl golang-lru-arc-v2.0.7/2q.go000066400000000000000000000150731450557771600154200ustar00rootroot00000000000000// Copyright (c) HashiCorp, Inc. // SPDX-License-Identifier: MPL-2.0 package lru import ( "errors" "sync" "github.com/hashicorp/golang-lru/v2/simplelru" ) const ( // Default2QRecentRatio is the ratio of the 2Q cache dedicated // to recently added entries that have only been accessed once. Default2QRecentRatio = 0.25 // Default2QGhostEntries is the default ratio of ghost // entries kept to track entries recently evicted Default2QGhostEntries = 0.50 ) // TwoQueueCache is a thread-safe fixed size 2Q cache. // 2Q is an enhancement over the standard LRU cache // in that it tracks both frequently and recently used // entries separately. This avoids a burst in access to new // entries from evicting frequently used entries. It adds some // additional tracking overhead to the standard LRU cache, and is // computationally about 2x the cost, and adds some metadata over // head. The ARCCache is similar, but does not require setting any // parameters. type TwoQueueCache[K comparable, V any] struct { size int recentSize int recentRatio float64 ghostRatio float64 recent simplelru.LRUCache[K, V] frequent simplelru.LRUCache[K, V] recentEvict simplelru.LRUCache[K, struct{}] lock sync.RWMutex } // New2Q creates a new TwoQueueCache using the default // values for the parameters. func New2Q[K comparable, V any](size int) (*TwoQueueCache[K, V], error) { return New2QParams[K, V](size, Default2QRecentRatio, Default2QGhostEntries) } // New2QParams creates a new TwoQueueCache using the provided // parameter values. func New2QParams[K comparable, V any](size int, recentRatio, ghostRatio float64) (*TwoQueueCache[K, V], error) { if size <= 0 { return nil, errors.New("invalid size") } if recentRatio < 0.0 || recentRatio > 1.0 { return nil, errors.New("invalid recent ratio") } if ghostRatio < 0.0 || ghostRatio > 1.0 { return nil, errors.New("invalid ghost ratio") } // Determine the sub-sizes recentSize := int(float64(size) * recentRatio) evictSize := int(float64(size) * ghostRatio) // Allocate the LRUs recent, err := simplelru.NewLRU[K, V](size, nil) if err != nil { return nil, err } frequent, err := simplelru.NewLRU[K, V](size, nil) if err != nil { return nil, err } recentEvict, err := simplelru.NewLRU[K, struct{}](evictSize, nil) if err != nil { return nil, err } // Initialize the cache c := &TwoQueueCache[K, V]{ size: size, recentSize: recentSize, recentRatio: recentRatio, ghostRatio: ghostRatio, recent: recent, frequent: frequent, recentEvict: recentEvict, } return c, nil } // Get looks up a key's value from the cache. func (c *TwoQueueCache[K, V]) Get(key K) (value V, ok bool) { c.lock.Lock() defer c.lock.Unlock() // Check if this is a frequent value if val, ok := c.frequent.Get(key); ok { return val, ok } // If the value is contained in recent, then we // promote it to frequent if val, ok := c.recent.Peek(key); ok { c.recent.Remove(key) c.frequent.Add(key, val) return val, ok } // No hit return } // Add adds a value to the cache. func (c *TwoQueueCache[K, V]) Add(key K, value V) { c.lock.Lock() defer c.lock.Unlock() // Check if the value is frequently used already, // and just update the value if c.frequent.Contains(key) { c.frequent.Add(key, value) return } // Check if the value is recently used, and promote // the value into the frequent list if c.recent.Contains(key) { c.recent.Remove(key) c.frequent.Add(key, value) return } // If the value was recently evicted, add it to the // frequently used list if c.recentEvict.Contains(key) { c.ensureSpace(true) c.recentEvict.Remove(key) c.frequent.Add(key, value) return } // Add to the recently seen list c.ensureSpace(false) c.recent.Add(key, value) } // ensureSpace is used to ensure we have space in the cache func (c *TwoQueueCache[K, V]) ensureSpace(recentEvict bool) { // If we have space, nothing to do recentLen := c.recent.Len() freqLen := c.frequent.Len() if recentLen+freqLen < c.size { return } // If the recent buffer is larger than // the target, evict from there if recentLen > 0 && (recentLen > c.recentSize || (recentLen == c.recentSize && !recentEvict)) { k, _, _ := c.recent.RemoveOldest() c.recentEvict.Add(k, struct{}{}) return } // Remove from the frequent list otherwise c.frequent.RemoveOldest() } // Len returns the number of items in the cache. func (c *TwoQueueCache[K, V]) Len() int { c.lock.RLock() defer c.lock.RUnlock() return c.recent.Len() + c.frequent.Len() } // Resize changes the cache size. func (c *TwoQueueCache[K, V]) Resize(size int) (evicted int) { c.lock.Lock() defer c.lock.Unlock() // Recalculate the sub-sizes recentSize := int(float64(size) * c.recentRatio) evictSize := int(float64(size) * c.ghostRatio) c.size = size c.recentSize = recentSize // ensureSpace diff := c.recent.Len() + c.frequent.Len() - size if diff < 0 { diff = 0 } for i := 0; i < diff; i++ { c.ensureSpace(true) } // Reallocate the LRUs c.recent.Resize(size) c.frequent.Resize(size) c.recentEvict.Resize(evictSize) return diff } // Keys returns a slice of the keys in the cache. // The frequently used keys are first in the returned slice. func (c *TwoQueueCache[K, V]) Keys() []K { c.lock.RLock() defer c.lock.RUnlock() k1 := c.frequent.Keys() k2 := c.recent.Keys() return append(k1, k2...) } // Values returns a slice of the values in the cache. // The frequently used values are first in the returned slice. func (c *TwoQueueCache[K, V]) Values() []V { c.lock.RLock() defer c.lock.RUnlock() v1 := c.frequent.Values() v2 := c.recent.Values() return append(v1, v2...) } // Remove removes the provided key from the cache. func (c *TwoQueueCache[K, V]) Remove(key K) { c.lock.Lock() defer c.lock.Unlock() if c.frequent.Remove(key) { return } if c.recent.Remove(key) { return } if c.recentEvict.Remove(key) { return } } // Purge is used to completely clear the cache. func (c *TwoQueueCache[K, V]) Purge() { c.lock.Lock() defer c.lock.Unlock() c.recent.Purge() c.frequent.Purge() c.recentEvict.Purge() } // Contains is used to check if the cache contains a key // without updating recency or frequency. func (c *TwoQueueCache[K, V]) Contains(key K) bool { c.lock.RLock() defer c.lock.RUnlock() return c.frequent.Contains(key) || c.recent.Contains(key) } // Peek is used to inspect the cache value of a key // without updating recency or frequency. func (c *TwoQueueCache[K, V]) Peek(key K) (value V, ok bool) { c.lock.RLock() defer c.lock.RUnlock() if val, ok := c.frequent.Peek(key); ok { return val, ok } return c.recent.Peek(key) } golang-lru-arc-v2.0.7/2q_test.go000066400000000000000000000151551450557771600164600ustar00rootroot00000000000000// Copyright (c) HashiCorp, Inc. // SPDX-License-Identifier: MPL-2.0 package lru import ( "testing" ) func Benchmark2Q_Rand(b *testing.B) { l, err := New2Q[int64, int64](8192) if err != nil { b.Fatalf("err: %v", err) } trace := make([]int64, b.N*2) for i := 0; i < b.N*2; i++ { trace[i] = getRand(b) % 32768 } b.ResetTimer() var hit, miss int for i := 0; i < 2*b.N; i++ { if i%2 == 0 { l.Add(trace[i], trace[i]) } else { if _, ok := l.Get(trace[i]); ok { hit++ } else { miss++ } } } b.Logf("hit: %d miss: %d ratio: %f", hit, miss, float64(hit)/float64(hit+miss)) } func Benchmark2Q_Freq(b *testing.B) { l, err := New2Q[int64, int64](8192) if err != nil { b.Fatalf("err: %v", err) } trace := make([]int64, b.N*2) for i := 0; i < b.N*2; i++ { if i%2 == 0 { trace[i] = getRand(b) % 16384 } else { trace[i] = getRand(b) % 32768 } } b.ResetTimer() for i := 0; i < b.N; i++ { l.Add(trace[i], trace[i]) } var hit, miss int for i := 0; i < b.N; i++ { if _, ok := l.Get(trace[i]); ok { hit++ } else { miss++ } } b.Logf("hit: %d miss: %d ratio: %f", hit, miss, float64(hit)/float64(hit+miss)) } func Test2Q_RandomOps(t *testing.T) { size := 128 l, err := New2Q[int64, int64](128) if err != nil { t.Fatalf("err: %v", err) } n := 200000 for i := 0; i < n; i++ { key := getRand(t) % 512 r := getRand(t) switch r % 3 { case 0: l.Add(key, key) case 1: l.Get(key) case 2: l.Remove(key) } if l.recent.Len()+l.frequent.Len() > size { t.Fatalf("bad: recent: %d freq: %d", l.recent.Len(), l.frequent.Len()) } } } func Test2Q_Get_RecentToFrequent(t *testing.T) { l, err := New2Q[int, int](128) if err != nil { t.Fatalf("err: %v", err) } // Touch all the entries, should be in t1 for i := 0; i < 128; i++ { l.Add(i, i) } if n := l.recent.Len(); n != 128 { t.Fatalf("bad: %d", n) } if n := l.frequent.Len(); n != 0 { t.Fatalf("bad: %d", n) } // Get should upgrade to t2 for i := 0; i < 128; i++ { if _, ok := l.Get(i); !ok { t.Fatalf("missing: %d", i) } } if n := l.recent.Len(); n != 0 { t.Fatalf("bad: %d", n) } if n := l.frequent.Len(); n != 128 { t.Fatalf("bad: %d", n) } // Get be from t2 for i := 0; i < 128; i++ { if _, ok := l.Get(i); !ok { t.Fatalf("missing: %d", i) } } if n := l.recent.Len(); n != 0 { t.Fatalf("bad: %d", n) } if n := l.frequent.Len(); n != 128 { t.Fatalf("bad: %d", n) } } func Test2Q_Add_RecentToFrequent(t *testing.T) { l, err := New2Q[int, int](128) if err != nil { t.Fatalf("err: %v", err) } // Add initially to recent l.Add(1, 1) if n := l.recent.Len(); n != 1 { t.Fatalf("bad: %d", n) } if n := l.frequent.Len(); n != 0 { t.Fatalf("bad: %d", n) } // Add should upgrade to frequent l.Add(1, 1) if n := l.recent.Len(); n != 0 { t.Fatalf("bad: %d", n) } if n := l.frequent.Len(); n != 1 { t.Fatalf("bad: %d", n) } // Add should remain in frequent l.Add(1, 1) if n := l.recent.Len(); n != 0 { t.Fatalf("bad: %d", n) } if n := l.frequent.Len(); n != 1 { t.Fatalf("bad: %d", n) } } func Test2Q_Add_RecentEvict(t *testing.T) { l, err := New2Q[int, int](4) if err != nil { t.Fatalf("err: %v", err) } // Add 1,2,3,4,5 -> Evict 1 l.Add(1, 1) l.Add(2, 2) l.Add(3, 3) l.Add(4, 4) l.Add(5, 5) if n := l.recent.Len(); n != 4 { t.Fatalf("bad: %d", n) } if n := l.recentEvict.Len(); n != 1 { t.Fatalf("bad: %d", n) } if n := l.frequent.Len(); n != 0 { t.Fatalf("bad: %d", n) } // Pull in the recently evicted l.Add(1, 1) if n := l.recent.Len(); n != 3 { t.Fatalf("bad: %d", n) } if n := l.recentEvict.Len(); n != 1 { t.Fatalf("bad: %d", n) } if n := l.frequent.Len(); n != 1 { t.Fatalf("bad: %d", n) } // Add 6, should cause another recent evict l.Add(6, 6) if n := l.recent.Len(); n != 3 { t.Fatalf("bad: %d", n) } if n := l.recentEvict.Len(); n != 2 { t.Fatalf("bad: %d", n) } if n := l.frequent.Len(); n != 1 { t.Fatalf("bad: %d", n) } } func Test2Q_Resize(t *testing.T) { l, err := New2Q[int, int](100) if err != nil { t.Fatalf("err: %v", err) } // Touch all the entries, should be in t1 for i := 0; i < 100; i++ { l.Add(i, i) } evicted := l.Resize(50) if evicted != 50 { t.Fatalf("bad: %d", evicted) } if n := l.recent.Len(); n != 50 { t.Fatalf("bad: %d", n) } if n := l.frequent.Len(); n != 0 { t.Fatalf("bad: %d", n) } l, err = New2Q[int, int](100) if err != nil { t.Fatalf("err: %v", err) } for i := 0; i < 100; i++ { l.Add(i, i) } for i := 0; i < 50; i++ { l.Add(i, i) } evicted = l.Resize(50) if evicted != 50 { t.Fatalf("bad: %d", evicted) } if n := l.recent.Len(); n != 12 { t.Fatalf("bad: %d", n) } if n := l.frequent.Len(); n != 38 { t.Fatalf("bad: %d", n) } l, err = New2Q[int, int](100) if err != nil { t.Fatalf("err: %v", err) } for i := 0; i < 100; i++ { l.Add(i, i) l.Add(i, i) } evicted = l.Resize(50) if evicted != 50 { t.Fatalf("bad: %d", evicted) } if n := l.recent.Len(); n != 0 { t.Fatalf("bad: %d", n) } if n := l.frequent.Len(); n != 50 { t.Fatalf("bad: %d", n) } } func Test2Q(t *testing.T) { l, err := New2Q[int, int](128) if err != nil { t.Fatalf("err: %v", err) } for i := 0; i < 256; i++ { l.Add(i, i) } if l.Len() != 128 { t.Fatalf("bad len: %v", l.Len()) } for i, k := range l.Keys() { if v, ok := l.Get(k); !ok || v != k || v != i+128 { t.Fatalf("bad key: %v", k) } } for i, v := range l.Values() { if v != i+128 { t.Fatalf("bad key: %v", v) } } for i := 0; i < 128; i++ { if _, ok := l.Get(i); ok { t.Fatalf("should be evicted") } } for i := 128; i < 256; i++ { if _, ok := l.Get(i); !ok { t.Fatalf("should not be evicted") } } for i := 128; i < 192; i++ { l.Remove(i) if _, ok := l.Get(i); ok { t.Fatalf("should be deleted") } } l.Purge() if l.Len() != 0 { t.Fatalf("bad len: %v", l.Len()) } if _, ok := l.Get(200); ok { t.Fatalf("should contain nothing") } } // Test that Contains doesn't update recent-ness func Test2Q_Contains(t *testing.T) { l, err := New2Q[int, int](2) if err != nil { t.Fatalf("err: %v", err) } l.Add(1, 1) l.Add(2, 2) if !l.Contains(1) { t.Errorf("1 should be contained") } l.Add(3, 3) if l.Contains(1) { t.Errorf("Contains should not have updated recent-ness of 1") } } // Test that Peek doesn't update recent-ness func Test2Q_Peek(t *testing.T) { l, err := New2Q[int, int](2) if err != nil { t.Fatalf("err: %v", err) } l.Add(1, 1) l.Add(2, 2) if v, ok := l.Peek(1); !ok || v != 1 { t.Errorf("1 should be set to 1: %v, %v", v, ok) } l.Add(3, 3) if l.Contains(1) { t.Errorf("should not have updated recent-ness of 1") } } golang-lru-arc-v2.0.7/LICENSE000066400000000000000000000371251450557771600155560ustar00rootroot00000000000000Copyright (c) 2014 HashiCorp, Inc. Mozilla Public License, version 2.0 1. Definitions 1.1. "Contributor" means each individual or legal entity that creates, contributes to the creation of, or owns Covered Software. 1.2. "Contributor Version" means the combination of the Contributions of others (if any) used by a Contributor and that particular Contributor's Contribution. 1.3. "Contribution" means Covered Software of a particular Contributor. 1.4. "Covered Software" means Source Code Form to which the initial Contributor has attached the notice in Exhibit A, the Executable Form of such Source Code Form, and Modifications of such Source Code Form, in each case including portions thereof. 1.5. "Incompatible With Secondary Licenses" means a. that the initial Contributor has attached the notice described in Exhibit B to the Covered Software; or b. that the Covered Software was made available under the terms of version 1.1 or earlier of the License, but not also under the terms of a Secondary License. 1.6. "Executable Form" means any form of the work other than Source Code Form. 1.7. "Larger Work" means a work that combines Covered Software with other material, in a separate file or files, that is not Covered Software. 1.8. "License" means this document. 1.9. "Licensable" means having the right to grant, to the maximum extent possible, whether at the time of the initial grant or subsequently, any and all of the rights conveyed by this License. 1.10. "Modifications" means any of the following: a. any file in Source Code Form that results from an addition to, deletion from, or modification of the contents of Covered Software; or b. any new file in Source Code Form that contains any Covered Software. 1.11. "Patent Claims" of a Contributor means any patent claim(s), including without limitation, method, process, and apparatus claims, in any patent Licensable by such Contributor that would be infringed, but for the grant of the License, by the making, using, selling, offering for sale, having made, import, or transfer of either its Contributions or its Contributor Version. 1.12. "Secondary License" means either the GNU General Public License, Version 2.0, the GNU Lesser General Public License, Version 2.1, the GNU Affero General Public License, Version 3.0, or any later versions of those licenses. 1.13. "Source Code Form" means the form of the work preferred for making modifications. 1.14. "You" (or "Your") means an individual or a legal entity exercising rights under this License. For legal entities, "You" includes any entity that controls, is controlled by, or is under common control with You. For purposes of this definition, "control" means (a) the power, direct or indirect, to cause the direction or management of such entity, whether by contract or otherwise, or (b) ownership of more than fifty percent (50%) of the outstanding shares or beneficial ownership of such entity. 2. License Grants and Conditions 2.1. Grants Each Contributor hereby grants You a world-wide, royalty-free, non-exclusive license: a. under intellectual property rights (other than patent or trademark) Licensable by such Contributor to use, reproduce, make available, modify, display, perform, distribute, and otherwise exploit its Contributions, either on an unmodified basis, with Modifications, or as part of a Larger Work; and b. under Patent Claims of such Contributor to make, use, sell, offer for sale, have made, import, and otherwise transfer either its Contributions or its Contributor Version. 2.2. Effective Date The licenses granted in Section 2.1 with respect to any Contribution become effective for each Contribution on the date the Contributor first distributes such Contribution. 2.3. Limitations on Grant Scope The licenses granted in this Section 2 are the only rights granted under this License. No additional rights or licenses will be implied from the distribution or licensing of Covered Software under this License. Notwithstanding Section 2.1(b) above, no patent license is granted by a Contributor: a. for any code that a Contributor has removed from Covered Software; or b. for infringements caused by: (i) Your and any other third party's modifications of Covered Software, or (ii) the combination of its Contributions with other software (except as part of its Contributor Version); or c. under Patent Claims infringed by Covered Software in the absence of its Contributions. This License does not grant any rights in the trademarks, service marks, or logos of any Contributor (except as may be necessary to comply with the notice requirements in Section 3.4). 2.4. Subsequent Licenses No Contributor makes additional grants as a result of Your choice to distribute the Covered Software under a subsequent version of this License (see Section 10.2) or under the terms of a Secondary License (if permitted under the terms of Section 3.3). 2.5. Representation Each Contributor represents that the Contributor believes its Contributions are its original creation(s) or it has sufficient rights to grant the rights to its Contributions conveyed by this License. 2.6. Fair Use This License is not intended to limit any rights You have under applicable copyright doctrines of fair use, fair dealing, or other equivalents. 2.7. Conditions Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted in Section 2.1. 3. Responsibilities 3.1. Distribution of Source Form All distribution of Covered Software in Source Code Form, including any Modifications that You create or to which You contribute, must be under the terms of this License. You must inform recipients that the Source Code Form of the Covered Software is governed by the terms of this License, and how they can obtain a copy of this License. You may not attempt to alter or restrict the recipients' rights in the Source Code Form. 3.2. Distribution of Executable Form If You distribute Covered Software in Executable Form then: a. such Covered Software must also be made available in Source Code Form, as described in Section 3.1, and You must inform recipients of the Executable Form how they can obtain a copy of such Source Code Form by reasonable means in a timely manner, at a charge no more than the cost of distribution to the recipient; and b. You may distribute such Executable Form under the terms of this License, or sublicense it under different terms, provided that the license for the Executable Form does not attempt to limit or alter the recipients' rights in the Source Code Form under this License. 3.3. Distribution of a Larger Work You may create and distribute a Larger Work under terms of Your choice, provided that You also comply with the requirements of this License for the Covered Software. If the Larger Work is a combination of Covered Software with a work governed by one or more Secondary Licenses, and the Covered Software is not Incompatible With Secondary Licenses, this License permits You to additionally distribute such Covered Software under the terms of such Secondary License(s), so that the recipient of the Larger Work may, at their option, further distribute the Covered Software under the terms of either this License or such Secondary License(s). 3.4. Notices You may not remove or alter the substance of any license notices (including copyright notices, patent notices, disclaimers of warranty, or limitations of liability) contained within the Source Code Form of the Covered Software, except that You may alter any license notices to the extent required to remedy known factual inaccuracies. 3.5. Application of Additional Terms You may choose to offer, and to charge a fee for, warranty, support, indemnity or liability obligations to one or more recipients of Covered Software. However, You may do so only on Your own behalf, and not on behalf of any Contributor. You must make it absolutely clear that any such warranty, support, indemnity, or liability obligation is offered by You alone, and You hereby agree to indemnify every Contributor for any liability incurred by such Contributor as a result of warranty, support, indemnity or liability terms You offer. You may include additional disclaimers of warranty and limitations of liability specific to any jurisdiction. 4. Inability to Comply Due to Statute or Regulation If it is impossible for You to comply with any of the terms of this License with respect to some or all of the Covered Software due to statute, judicial order, or regulation then You must: (a) comply with the terms of this License to the maximum extent possible; and (b) describe the limitations and the code they affect. Such description must be placed in a text file included with all distributions of the Covered Software under this License. Except to the extent prohibited by statute or regulation, such description must be sufficiently detailed for a recipient of ordinary skill to be able to understand it. 5. Termination 5.1. The rights granted under this License will terminate automatically if You fail to comply with any of its terms. However, if You become compliant, then the rights granted under this License from a particular Contributor are reinstated (a) provisionally, unless and until such Contributor explicitly and finally terminates Your grants, and (b) on an ongoing basis, if such Contributor fails to notify You of the non-compliance by some reasonable means prior to 60 days after You have come back into compliance. Moreover, Your grants from a particular Contributor are reinstated on an ongoing basis if such Contributor notifies You of the non-compliance by some reasonable means, this is the first time You have received notice of non-compliance with this License from such Contributor, and You become compliant prior to 30 days after Your receipt of the notice. 5.2. If You initiate litigation against any entity by asserting a patent infringement claim (excluding declaratory judgment actions, counter-claims, and cross-claims) alleging that a Contributor Version directly or indirectly infringes any patent, then the rights granted to You by any and all Contributors for the Covered Software under Section 2.1 of this License shall terminate. 5.3. In the event of termination under Sections 5.1 or 5.2 above, all end user license agreements (excluding distributors and resellers) which have been validly granted by You or Your distributors under this License prior to termination shall survive termination. 6. Disclaimer of Warranty Covered Software is provided under this License on an "as is" basis, without warranty of any kind, either expressed, implied, or statutory, including, without limitation, warranties that the Covered Software is free of defects, merchantable, fit for a particular purpose or non-infringing. The entire risk as to the quality and performance of the Covered Software is with You. Should any Covered Software prove defective in any respect, You (not any Contributor) assume the cost of any necessary servicing, repair, or correction. This disclaimer of warranty constitutes an essential part of this License. No use of any Covered Software is authorized under this License except under this disclaimer. 7. Limitation of Liability Under no circumstances and under no legal theory, whether tort (including negligence), contract, or otherwise, shall any Contributor, or anyone who distributes Covered Software as permitted above, be liable to You for any direct, indirect, special, incidental, or consequential damages of any character including, without limitation, damages for lost profits, loss of goodwill, work stoppage, computer failure or malfunction, or any and all other commercial damages or losses, even if such party shall have been informed of the possibility of such damages. This limitation of liability shall not apply to liability for death or personal injury resulting from such party's negligence to the extent applicable law prohibits such limitation. Some jurisdictions do not allow the exclusion or limitation of incidental or consequential damages, so this exclusion and limitation may not apply to You. 8. Litigation Any litigation relating to this License may be brought only in the courts of a jurisdiction where the defendant maintains its principal place of business and such litigation shall be governed by laws of that jurisdiction, without reference to its conflict-of-law provisions. Nothing in this Section shall prevent a party's ability to bring cross-claims or counter-claims. 9. Miscellaneous This License represents the complete agreement concerning the subject matter hereof. If any provision of this License is held to be unenforceable, such provision shall be reformed only to the extent necessary to make it enforceable. Any law or regulation which provides that the language of a contract shall be construed against the drafter shall not be used to construe this License against a Contributor. 10. Versions of the License 10.1. New Versions Mozilla Foundation is the license steward. Except as provided in Section 10.3, no one other than the license steward has the right to modify or publish new versions of this License. Each version will be given a distinguishing version number. 10.2. Effect of New Versions You may distribute the Covered Software under the terms of the version of the License under which You originally received the Covered Software, or under the terms of any subsequent version published by the license steward. 10.3. Modified Versions If you create software not governed by this License, and you want to create a new license for such software, you may create and use a modified version of this License if you rename the license and remove any references to the name of the license steward (except to note that such modified license differs from this License). 10.4. Distributing Source Code Form that is Incompatible With Secondary Licenses If You choose to distribute Source Code Form that is Incompatible With Secondary Licenses under the terms of this version of the License, the notice described in Exhibit B of this License must be attached. Exhibit A - Source Code Form License Notice This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0. If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/. If it is not possible or desirable to put the notice in a particular file, then You may include the notice in a location (such as a LICENSE file in a relevant directory) where a recipient would be likely to look for such a notice. You may add additional accurate notices of copyright ownership. Exhibit B - "Incompatible With Secondary Licenses" Notice This Source Code Form is "Incompatible With Secondary Licenses", as defined by the Mozilla Public License, v. 2.0. golang-lru-arc-v2.0.7/README.md000066400000000000000000000030401450557771600160150ustar00rootroot00000000000000golang-lru ========== This provides the `lru` package which implements a fixed-size thread safe LRU cache. It is based on the cache in Groupcache. Documentation ============= Full docs are available on [Go Packages](https://pkg.go.dev/github.com/hashicorp/golang-lru/v2) LRU cache example ================= ```go package main import ( "fmt" "github.com/hashicorp/golang-lru/v2" ) func main() { l, _ := lru.New[int, any](128) for i := 0; i < 256; i++ { l.Add(i, nil) } if l.Len() != 128 { panic(fmt.Sprintf("bad len: %v", l.Len())) } } ``` Expirable LRU cache example =========================== ```go package main import ( "fmt" "time" "github.com/hashicorp/golang-lru/v2/expirable" ) func main() { // make cache with 10ms TTL and 5 max keys cache := expirable.NewLRU[string, string](5, nil, time.Millisecond*10) // set value under key1. cache.Add("key1", "val1") // get value under key1 r, ok := cache.Get("key1") // check for OK value if ok { fmt.Printf("value before expiration is found: %v, value: %q\n", ok, r) } // wait for cache to expire time.Sleep(time.Millisecond * 12) // get value under key1 after key expiration r, ok = cache.Get("key1") fmt.Printf("value after expiration is found: %v, value: %q\n", ok, r) // set value under key2, would evict old entry because it is already expired. cache.Add("key2", "val2") fmt.Printf("Cache len: %d\n", cache.Len()) // Output: // value before expiration is found: true, value: "val1" // value after expiration is found: false, value: "" // Cache len: 1 } ``` golang-lru-arc-v2.0.7/arc/000077500000000000000000000000001450557771600153065ustar00rootroot00000000000000golang-lru-arc-v2.0.7/arc/arc.go000066400000000000000000000136631450557771600164130ustar00rootroot00000000000000// Copyright (c) HashiCorp, Inc. // SPDX-License-Identifier: MPL-2.0 package arc import ( "sync" "github.com/hashicorp/golang-lru/v2/simplelru" ) // ARCCache is a thread-safe fixed size Adaptive Replacement Cache (ARC). // ARC is an enhancement over the standard LRU cache in that tracks both // frequency and recency of use. This avoids a burst in access to new // entries from evicting the frequently used older entries. It adds some // additional tracking overhead to a standard LRU cache, computationally // it is roughly 2x the cost, and the extra memory overhead is linear // with the size of the cache. ARC has been patented by IBM, but is // similar to the TwoQueueCache (2Q) which requires setting parameters. type ARCCache[K comparable, V any] struct { size int // Size is the total capacity of the cache p int // P is the dynamic preference towards T1 or T2 t1 simplelru.LRUCache[K, V] // T1 is the LRU for recently accessed items b1 simplelru.LRUCache[K, struct{}] // B1 is the LRU for evictions from t1 t2 simplelru.LRUCache[K, V] // T2 is the LRU for frequently accessed items b2 simplelru.LRUCache[K, struct{}] // B2 is the LRU for evictions from t2 lock sync.RWMutex } // NewARC creates an ARC of the given size func NewARC[K comparable, V any](size int) (*ARCCache[K, V], error) { // Create the sub LRUs b1, err := simplelru.NewLRU[K, struct{}](size, nil) if err != nil { return nil, err } b2, err := simplelru.NewLRU[K, struct{}](size, nil) if err != nil { return nil, err } t1, err := simplelru.NewLRU[K, V](size, nil) if err != nil { return nil, err } t2, err := simplelru.NewLRU[K, V](size, nil) if err != nil { return nil, err } // Initialize the ARC c := &ARCCache[K, V]{ size: size, p: 0, t1: t1, b1: b1, t2: t2, b2: b2, } return c, nil } // Get looks up a key's value from the cache. func (c *ARCCache[K, V]) Get(key K) (value V, ok bool) { c.lock.Lock() defer c.lock.Unlock() // If the value is contained in T1 (recent), then // promote it to T2 (frequent) if val, ok := c.t1.Peek(key); ok { c.t1.Remove(key) c.t2.Add(key, val) return val, ok } // Check if the value is contained in T2 (frequent) if val, ok := c.t2.Get(key); ok { return val, ok } // No hit return } // Add adds a value to the cache. func (c *ARCCache[K, V]) Add(key K, value V) { c.lock.Lock() defer c.lock.Unlock() // Check if the value is contained in T1 (recent), and potentially // promote it to frequent T2 if c.t1.Contains(key) { c.t1.Remove(key) c.t2.Add(key, value) return } // Check if the value is already in T2 (frequent) and update it if c.t2.Contains(key) { c.t2.Add(key, value) return } // Check if this value was recently evicted as part of the // recently used list if c.b1.Contains(key) { // T1 set is too small, increase P appropriately delta := 1 b1Len := c.b1.Len() b2Len := c.b2.Len() if b2Len > b1Len { delta = b2Len / b1Len } if c.p+delta >= c.size { c.p = c.size } else { c.p += delta } // Potentially need to make room in the cache if c.t1.Len()+c.t2.Len() >= c.size { c.replace(false) } // Remove from B1 c.b1.Remove(key) // Add the key to the frequently used list c.t2.Add(key, value) return } // Check if this value was recently evicted as part of the // frequently used list if c.b2.Contains(key) { // T2 set is too small, decrease P appropriately delta := 1 b1Len := c.b1.Len() b2Len := c.b2.Len() if b1Len > b2Len { delta = b1Len / b2Len } if delta >= c.p { c.p = 0 } else { c.p -= delta } // Potentially need to make room in the cache if c.t1.Len()+c.t2.Len() >= c.size { c.replace(true) } // Remove from B2 c.b2.Remove(key) // Add the key to the frequently used list c.t2.Add(key, value) return } // Potentially need to make room in the cache if c.t1.Len()+c.t2.Len() >= c.size { c.replace(false) } // Keep the size of the ghost buffers trim if c.b1.Len() > c.size-c.p { c.b1.RemoveOldest() } if c.b2.Len() > c.p { c.b2.RemoveOldest() } // Add to the recently seen list c.t1.Add(key, value) } // replace is used to adaptively evict from either T1 or T2 // based on the current learned value of P func (c *ARCCache[K, V]) replace(b2ContainsKey bool) { t1Len := c.t1.Len() if t1Len > 0 && (t1Len > c.p || (t1Len == c.p && b2ContainsKey)) { k, _, ok := c.t1.RemoveOldest() if ok { c.b1.Add(k, struct{}{}) } } else { k, _, ok := c.t2.RemoveOldest() if ok { c.b2.Add(k, struct{}{}) } } } // Len returns the number of cached entries func (c *ARCCache[K, V]) Len() int { c.lock.RLock() defer c.lock.RUnlock() return c.t1.Len() + c.t2.Len() } // Keys returns all the cached keys func (c *ARCCache[K, V]) Keys() []K { c.lock.RLock() defer c.lock.RUnlock() k1 := c.t1.Keys() k2 := c.t2.Keys() return append(k1, k2...) } // Values returns all the cached values func (c *ARCCache[K, V]) Values() []V { c.lock.RLock() defer c.lock.RUnlock() v1 := c.t1.Values() v2 := c.t2.Values() return append(v1, v2...) } // Remove is used to purge a key from the cache func (c *ARCCache[K, V]) Remove(key K) { c.lock.Lock() defer c.lock.Unlock() if c.t1.Remove(key) { return } if c.t2.Remove(key) { return } if c.b1.Remove(key) { return } if c.b2.Remove(key) { return } } // Purge is used to clear the cache func (c *ARCCache[K, V]) Purge() { c.lock.Lock() defer c.lock.Unlock() c.t1.Purge() c.t2.Purge() c.b1.Purge() c.b2.Purge() } // Contains is used to check if the cache contains a key // without updating recency or frequency. func (c *ARCCache[K, V]) Contains(key K) bool { c.lock.RLock() defer c.lock.RUnlock() return c.t1.Contains(key) || c.t2.Contains(key) } // Peek is used to inspect the cache value of a key // without updating recency or frequency. func (c *ARCCache[K, V]) Peek(key K) (value V, ok bool) { c.lock.RLock() defer c.lock.RUnlock() if val, ok := c.t1.Peek(key); ok { return val, ok } return c.t2.Peek(key) } golang-lru-arc-v2.0.7/arc/arc_test.go000066400000000000000000000156351450557771600174530ustar00rootroot00000000000000// Copyright (c) HashiCorp, Inc. // SPDX-License-Identifier: MPL-2.0 package arc import ( "crypto/rand" "math" "math/big" mathrand "math/rand" "testing" "time" ) func getRand(tb testing.TB) int64 { out, err := rand.Int(rand.Reader, big.NewInt(math.MaxInt64)) if err != nil { tb.Fatal(err) } return out.Int64() } func init() { mathrand.Seed(time.Now().Unix()) } func BenchmarkARC_Rand(b *testing.B) { l, err := NewARC[int64, int64](8192) if err != nil { b.Fatalf("err: %v", err) } trace := make([]int64, b.N*2) for i := 0; i < b.N*2; i++ { trace[i] = getRand(b) % 32768 } b.ResetTimer() var hit, miss int for i := 0; i < 2*b.N; i++ { if i%2 == 0 { l.Add(trace[i], trace[i]) } else { if _, ok := l.Get(trace[i]); ok { hit++ } else { miss++ } } } b.Logf("hit: %d miss: %d ratio: %f", hit, miss, float64(hit)/float64(hit+miss)) } func BenchmarkARC_Freq(b *testing.B) { l, err := NewARC[int64, int64](8192) if err != nil { b.Fatalf("err: %v", err) } trace := make([]int64, b.N*2) for i := 0; i < b.N*2; i++ { if i%2 == 0 { trace[i] = getRand(b) % 16384 } else { trace[i] = getRand(b) % 32768 } } b.ResetTimer() for i := 0; i < b.N; i++ { l.Add(trace[i], trace[i]) } var hit, miss int for i := 0; i < b.N; i++ { if _, ok := l.Get(trace[i]); ok { hit++ } else { miss++ } } b.Logf("hit: %d miss: %d ratio: %f", hit, miss, float64(hit)/float64(hit+miss)) } func TestARC_RandomOps(t *testing.T) { size := 128 l, err := NewARC[int64, int64](128) if err != nil { t.Fatalf("err: %v", err) } n := 200000 for i := 0; i < n; i++ { key := getRand(t) % 512 r := getRand(t) switch r % 3 { case 0: l.Add(key, key) case 1: l.Get(key) case 2: l.Remove(key) } if l.t1.Len()+l.t2.Len() > size { t.Fatalf("bad: t1: %d t2: %d b1: %d b2: %d p: %d", l.t1.Len(), l.t2.Len(), l.b1.Len(), l.b2.Len(), l.p) } if l.b1.Len()+l.b2.Len() > size { t.Fatalf("bad: t1: %d t2: %d b1: %d b2: %d p: %d", l.t1.Len(), l.t2.Len(), l.b1.Len(), l.b2.Len(), l.p) } } } func TestARC_Get_RecentToFrequent(t *testing.T) { l, err := NewARC[int, int](128) if err != nil { t.Fatalf("err: %v", err) } // Touch all the entries, should be in t1 for i := 0; i < 128; i++ { l.Add(i, i) } if n := l.t1.Len(); n != 128 { t.Fatalf("bad: %d", n) } if n := l.t2.Len(); n != 0 { t.Fatalf("bad: %d", n) } // Get should upgrade to t2 for i := 0; i < 128; i++ { if _, ok := l.Get(i); !ok { t.Fatalf("missing: %d", i) } } if n := l.t1.Len(); n != 0 { t.Fatalf("bad: %d", n) } if n := l.t2.Len(); n != 128 { t.Fatalf("bad: %d", n) } // Get be from t2 for i := 0; i < 128; i++ { if _, ok := l.Get(i); !ok { t.Fatalf("missing: %d", i) } } if n := l.t1.Len(); n != 0 { t.Fatalf("bad: %d", n) } if n := l.t2.Len(); n != 128 { t.Fatalf("bad: %d", n) } } func TestARC_Add_RecentToFrequent(t *testing.T) { l, err := NewARC[int, int](128) if err != nil { t.Fatalf("err: %v", err) } // Add initially to t1 l.Add(1, 1) if n := l.t1.Len(); n != 1 { t.Fatalf("bad: %d", n) } if n := l.t2.Len(); n != 0 { t.Fatalf("bad: %d", n) } // Add should upgrade to t2 l.Add(1, 1) if n := l.t1.Len(); n != 0 { t.Fatalf("bad: %d", n) } if n := l.t2.Len(); n != 1 { t.Fatalf("bad: %d", n) } // Add should remain in t2 l.Add(1, 1) if n := l.t1.Len(); n != 0 { t.Fatalf("bad: %d", n) } if n := l.t2.Len(); n != 1 { t.Fatalf("bad: %d", n) } } func TestARC_Adaptive(t *testing.T) { l, err := NewARC[int, int](4) if err != nil { t.Fatalf("err: %v", err) } // Fill t1 for i := 0; i < 4; i++ { l.Add(i, i) } if n := l.t1.Len(); n != 4 { t.Fatalf("bad: %d", n) } // Move to t2 l.Get(0) l.Get(1) if n := l.t2.Len(); n != 2 { t.Fatalf("bad: %d", n) } // Evict from t1 l.Add(4, 4) if n := l.b1.Len(); n != 1 { t.Fatalf("bad: %d", n) } // Current state // t1 : (MRU) [4, 3] (LRU) // t2 : (MRU) [1, 0] (LRU) // b1 : (MRU) [2] (LRU) // b2 : (MRU) [] (LRU) // Add 2, should cause hit on b1 l.Add(2, 2) if n := l.b1.Len(); n != 1 { t.Fatalf("bad: %d", n) } if l.p != 1 { t.Fatalf("bad: %d", l.p) } if n := l.t2.Len(); n != 3 { t.Fatalf("bad: %d", n) } // Current state // t1 : (MRU) [4] (LRU) // t2 : (MRU) [2, 1, 0] (LRU) // b1 : (MRU) [3] (LRU) // b2 : (MRU) [] (LRU) // Add 4, should migrate to t2 l.Add(4, 4) if n := l.t1.Len(); n != 0 { t.Fatalf("bad: %d", n) } if n := l.t2.Len(); n != 4 { t.Fatalf("bad: %d", n) } // Current state // t1 : (MRU) [] (LRU) // t2 : (MRU) [4, 2, 1, 0] (LRU) // b1 : (MRU) [3] (LRU) // b2 : (MRU) [] (LRU) // Add 4, should evict to b2 l.Add(5, 5) if n := l.t1.Len(); n != 1 { t.Fatalf("bad: %d", n) } if n := l.t2.Len(); n != 3 { t.Fatalf("bad: %d", n) } if n := l.b2.Len(); n != 1 { t.Fatalf("bad: %d", n) } // Current state // t1 : (MRU) [5] (LRU) // t2 : (MRU) [4, 2, 1] (LRU) // b1 : (MRU) [3] (LRU) // b2 : (MRU) [0] (LRU) // Add 0, should decrease p l.Add(0, 0) if n := l.t1.Len(); n != 0 { t.Fatalf("bad: %d", n) } if n := l.t2.Len(); n != 4 { t.Fatalf("bad: %d", n) } if n := l.b1.Len(); n != 2 { t.Fatalf("bad: %d", n) } if n := l.b2.Len(); n != 0 { t.Fatalf("bad: %d", n) } if l.p != 0 { t.Fatalf("bad: %d", l.p) } // Current state // t1 : (MRU) [] (LRU) // t2 : (MRU) [0, 4, 2, 1] (LRU) // b1 : (MRU) [5, 3] (LRU) // b2 : (MRU) [0] (LRU) } func TestARC(t *testing.T) { l, err := NewARC[int, int](128) if err != nil { t.Fatalf("err: %v", err) } for i := 0; i < 256; i++ { l.Add(i, i) } if l.Len() != 128 { t.Fatalf("bad len: %v", l.Len()) } for i, k := range l.Keys() { if v, ok := l.Get(k); !ok || v != k || v != i+128 { t.Fatalf("bad key: %v", k) } } for i, v := range l.Values() { if v != i+128 { t.Fatalf("bad value: %v", v) } } for i := 0; i < 128; i++ { if _, ok := l.Get(i); ok { t.Fatalf("should be evicted") } } for i := 128; i < 256; i++ { if _, ok := l.Get(i); !ok { t.Fatalf("should not be evicted") } } for i := 128; i < 192; i++ { l.Remove(i) if _, ok := l.Get(i); ok { t.Fatalf("should be deleted") } } l.Purge() if l.Len() != 0 { t.Fatalf("bad len: %v", l.Len()) } if _, ok := l.Get(200); ok { t.Fatalf("should contain nothing") } } // Test that Contains doesn't update recent-ness func TestARC_Contains(t *testing.T) { l, err := NewARC[int, int](2) if err != nil { t.Fatalf("err: %v", err) } l.Add(1, 1) l.Add(2, 2) if !l.Contains(1) { t.Errorf("1 should be contained") } l.Add(3, 3) if l.Contains(1) { t.Errorf("Contains should not have updated recent-ness of 1") } } // Test that Peek doesn't update recent-ness func TestARC_Peek(t *testing.T) { l, err := NewARC[int, int](2) if err != nil { t.Fatalf("err: %v", err) } l.Add(1, 1) l.Add(2, 2) if v, ok := l.Peek(1); !ok || v != 1 { t.Errorf("1 should be set to 1: %v, %v", v, ok) } l.Add(3, 3) if l.Contains(1) { t.Errorf("should not have updated recent-ness of 1") } } golang-lru-arc-v2.0.7/arc/go.mod000066400000000000000000000001521450557771600164120ustar00rootroot00000000000000module github.com/hashicorp/golang-lru/arc/v2 go 1.18 require github.com/hashicorp/golang-lru/v2 v2.0.7 golang-lru-arc-v2.0.7/arc/go.sum000066400000000000000000000002731450557771600164430ustar00rootroot00000000000000github.com/hashicorp/golang-lru/v2 v2.0.7 h1:a+bsQ5rvGLjzHuww6tVxozPZFVghXaHOwFs4luLUK2k= github.com/hashicorp/golang-lru/v2 v2.0.7/go.mod h1:QeFd9opnmA6QUJc5vARoKUSoFhyfM2/ZepoAG6RGpeM= golang-lru-arc-v2.0.7/doc.go000066400000000000000000000021131450557771600156320ustar00rootroot00000000000000// Copyright (c) HashiCorp, Inc. // SPDX-License-Identifier: MPL-2.0 // Package lru provides three different LRU caches of varying sophistication. // // Cache is a simple LRU cache. It is based on the LRU implementation in // groupcache: https://github.com/golang/groupcache/tree/master/lru // // TwoQueueCache tracks frequently used and recently used entries separately. // This avoids a burst of accesses from taking out frequently used entries, at // the cost of about 2x computational overhead and some extra bookkeeping. // // ARCCache is an adaptive replacement cache. It tracks recent evictions as well // as recent usage in both the frequent and recent caches. Its computational // overhead is comparable to TwoQueueCache, but the memory overhead is linear // with the size of the cache. // // ARC has been patented by IBM, so do not use it if that is problematic for // your program. For this reason, it is in a separate go module contained within // this repository. // // All caches in this package take locks while operating, and are therefore // thread-safe for consumers. package lru golang-lru-arc-v2.0.7/expirable/000077500000000000000000000000001450557771600165145ustar00rootroot00000000000000golang-lru-arc-v2.0.7/expirable/expirable_lru.go000066400000000000000000000210471450557771600217040ustar00rootroot00000000000000// Copyright (c) HashiCorp, Inc. // SPDX-License-Identifier: MPL-2.0 package expirable import ( "sync" "time" "github.com/hashicorp/golang-lru/v2/internal" ) // EvictCallback is used to get a callback when a cache entry is evicted type EvictCallback[K comparable, V any] func(key K, value V) // LRU implements a thread-safe LRU with expirable entries. type LRU[K comparable, V any] struct { size int evictList *internal.LruList[K, V] items map[K]*internal.Entry[K, V] onEvict EvictCallback[K, V] // expirable options mu sync.Mutex ttl time.Duration done chan struct{} // buckets for expiration buckets []bucket[K, V] // uint8 because it's number between 0 and numBuckets nextCleanupBucket uint8 } // bucket is a container for holding entries to be expired type bucket[K comparable, V any] struct { entries map[K]*internal.Entry[K, V] newestEntry time.Time } // noEvictionTTL - very long ttl to prevent eviction const noEvictionTTL = time.Hour * 24 * 365 * 10 // because of uint8 usage for nextCleanupBucket, should not exceed 256. // casting it as uint8 explicitly requires type conversions in multiple places const numBuckets = 100 // NewLRU returns a new thread-safe cache with expirable entries. // // Size parameter set to 0 makes cache of unlimited size, e.g. turns LRU mechanism off. // // Providing 0 TTL turns expiring off. // // Delete expired entries every 1/100th of ttl value. Goroutine which deletes expired entries runs indefinitely. func NewLRU[K comparable, V any](size int, onEvict EvictCallback[K, V], ttl time.Duration) *LRU[K, V] { if size < 0 { size = 0 } if ttl <= 0 { ttl = noEvictionTTL } res := LRU[K, V]{ ttl: ttl, size: size, evictList: internal.NewList[K, V](), items: make(map[K]*internal.Entry[K, V]), onEvict: onEvict, done: make(chan struct{}), } // initialize the buckets res.buckets = make([]bucket[K, V], numBuckets) for i := 0; i < numBuckets; i++ { res.buckets[i] = bucket[K, V]{entries: make(map[K]*internal.Entry[K, V])} } // enable deleteExpired() running in separate goroutine for cache with non-zero TTL // // Important: done channel is never closed, so deleteExpired() goroutine will never exit, // it's decided to add functionality to close it in the version later than v2. if res.ttl != noEvictionTTL { go func(done <-chan struct{}) { ticker := time.NewTicker(res.ttl / numBuckets) defer ticker.Stop() for { select { case <-done: return case <-ticker.C: res.deleteExpired() } } }(res.done) } return &res } // Purge clears the cache completely. // onEvict is called for each evicted key. func (c *LRU[K, V]) Purge() { c.mu.Lock() defer c.mu.Unlock() for k, v := range c.items { if c.onEvict != nil { c.onEvict(k, v.Value) } delete(c.items, k) } for _, b := range c.buckets { for _, ent := range b.entries { delete(b.entries, ent.Key) } } c.evictList.Init() } // Add adds a value to the cache. Returns true if an eviction occurred. // Returns false if there was no eviction: the item was already in the cache, // or the size was not exceeded. func (c *LRU[K, V]) Add(key K, value V) (evicted bool) { c.mu.Lock() defer c.mu.Unlock() now := time.Now() // Check for existing item if ent, ok := c.items[key]; ok { c.evictList.MoveToFront(ent) c.removeFromBucket(ent) // remove the entry from its current bucket as expiresAt is renewed ent.Value = value ent.ExpiresAt = now.Add(c.ttl) c.addToBucket(ent) return false } // Add new item ent := c.evictList.PushFrontExpirable(key, value, now.Add(c.ttl)) c.items[key] = ent c.addToBucket(ent) // adds the entry to the appropriate bucket and sets entry.expireBucket evict := c.size > 0 && c.evictList.Length() > c.size // Verify size not exceeded if evict { c.removeOldest() } return evict } // Get looks up a key's value from the cache. func (c *LRU[K, V]) Get(key K) (value V, ok bool) { c.mu.Lock() defer c.mu.Unlock() var ent *internal.Entry[K, V] if ent, ok = c.items[key]; ok { // Expired item check if time.Now().After(ent.ExpiresAt) { return value, false } c.evictList.MoveToFront(ent) return ent.Value, true } return } // Contains checks if a key is in the cache, without updating the recent-ness // or deleting it for being stale. func (c *LRU[K, V]) Contains(key K) (ok bool) { c.mu.Lock() defer c.mu.Unlock() _, ok = c.items[key] return ok } // Peek returns the key value (or undefined if not found) without updating // the "recently used"-ness of the key. func (c *LRU[K, V]) Peek(key K) (value V, ok bool) { c.mu.Lock() defer c.mu.Unlock() var ent *internal.Entry[K, V] if ent, ok = c.items[key]; ok { // Expired item check if time.Now().After(ent.ExpiresAt) { return value, false } return ent.Value, true } return } // Remove removes the provided key from the cache, returning if the // key was contained. func (c *LRU[K, V]) Remove(key K) bool { c.mu.Lock() defer c.mu.Unlock() if ent, ok := c.items[key]; ok { c.removeElement(ent) return true } return false } // RemoveOldest removes the oldest item from the cache. func (c *LRU[K, V]) RemoveOldest() (key K, value V, ok bool) { c.mu.Lock() defer c.mu.Unlock() if ent := c.evictList.Back(); ent != nil { c.removeElement(ent) return ent.Key, ent.Value, true } return } // GetOldest returns the oldest entry func (c *LRU[K, V]) GetOldest() (key K, value V, ok bool) { c.mu.Lock() defer c.mu.Unlock() if ent := c.evictList.Back(); ent != nil { return ent.Key, ent.Value, true } return } // Keys returns a slice of the keys in the cache, from oldest to newest. func (c *LRU[K, V]) Keys() []K { c.mu.Lock() defer c.mu.Unlock() keys := make([]K, 0, len(c.items)) for ent := c.evictList.Back(); ent != nil; ent = ent.PrevEntry() { keys = append(keys, ent.Key) } return keys } // Values returns a slice of the values in the cache, from oldest to newest. // Expired entries are filtered out. func (c *LRU[K, V]) Values() []V { c.mu.Lock() defer c.mu.Unlock() values := make([]V, len(c.items)) i := 0 now := time.Now() for ent := c.evictList.Back(); ent != nil; ent = ent.PrevEntry() { if now.After(ent.ExpiresAt) { continue } values[i] = ent.Value i++ } return values } // Len returns the number of items in the cache. func (c *LRU[K, V]) Len() int { c.mu.Lock() defer c.mu.Unlock() return c.evictList.Length() } // Resize changes the cache size. Size of 0 means unlimited. func (c *LRU[K, V]) Resize(size int) (evicted int) { c.mu.Lock() defer c.mu.Unlock() if size <= 0 { c.size = 0 return 0 } diff := c.evictList.Length() - size if diff < 0 { diff = 0 } for i := 0; i < diff; i++ { c.removeOldest() } c.size = size return diff } // Close destroys cleanup goroutine. To clean up the cache, run Purge() before Close(). // func (c *LRU[K, V]) Close() { // c.mu.Lock() // defer c.mu.Unlock() // select { // case <-c.done: // return // default: // } // close(c.done) // } // removeOldest removes the oldest item from the cache. Has to be called with lock! func (c *LRU[K, V]) removeOldest() { if ent := c.evictList.Back(); ent != nil { c.removeElement(ent) } } // removeElement is used to remove a given list element from the cache. Has to be called with lock! func (c *LRU[K, V]) removeElement(e *internal.Entry[K, V]) { c.evictList.Remove(e) delete(c.items, e.Key) c.removeFromBucket(e) if c.onEvict != nil { c.onEvict(e.Key, e.Value) } } // deleteExpired deletes expired records from the oldest bucket, waiting for the newest entry // in it to expire first. func (c *LRU[K, V]) deleteExpired() { c.mu.Lock() bucketIdx := c.nextCleanupBucket timeToExpire := time.Until(c.buckets[bucketIdx].newestEntry) // wait for newest entry to expire before cleanup without holding lock if timeToExpire > 0 { c.mu.Unlock() time.Sleep(timeToExpire) c.mu.Lock() } for _, ent := range c.buckets[bucketIdx].entries { c.removeElement(ent) } c.nextCleanupBucket = (c.nextCleanupBucket + 1) % numBuckets c.mu.Unlock() } // addToBucket adds entry to expire bucket so that it will be cleaned up when the time comes. Has to be called with lock! func (c *LRU[K, V]) addToBucket(e *internal.Entry[K, V]) { bucketID := (numBuckets + c.nextCleanupBucket - 1) % numBuckets e.ExpireBucket = bucketID c.buckets[bucketID].entries[e.Key] = e if c.buckets[bucketID].newestEntry.Before(e.ExpiresAt) { c.buckets[bucketID].newestEntry = e.ExpiresAt } } // removeFromBucket removes the entry from its corresponding bucket. Has to be called with lock! func (c *LRU[K, V]) removeFromBucket(e *internal.Entry[K, V]) { delete(c.buckets[e.ExpireBucket].entries, e.Key) } golang-lru-arc-v2.0.7/expirable/expirable_lru_test.go000066400000000000000000000266541450557771600227540ustar00rootroot00000000000000// Copyright (c) HashiCorp, Inc. // SPDX-License-Identifier: MPL-2.0 package expirable import ( "crypto/rand" "fmt" "math" "math/big" "reflect" "sync" "testing" "time" "github.com/hashicorp/golang-lru/v2/simplelru" ) func BenchmarkLRU_Rand_NoExpire(b *testing.B) { l := NewLRU[int64, int64](8192, nil, 0) trace := make([]int64, b.N*2) for i := 0; i < b.N*2; i++ { trace[i] = getRand(b) % 32768 } b.ResetTimer() var hit, miss int for i := 0; i < 2*b.N; i++ { if i%2 == 0 { l.Add(trace[i], trace[i]) } else { if _, ok := l.Get(trace[i]); ok { hit++ } else { miss++ } } } b.Logf("hit: %d miss: %d ratio: %f", hit, miss, float64(hit)/float64(hit+miss)) } func BenchmarkLRU_Freq_NoExpire(b *testing.B) { l := NewLRU[int64, int64](8192, nil, 0) trace := make([]int64, b.N*2) for i := 0; i < b.N*2; i++ { if i%2 == 0 { trace[i] = getRand(b) % 16384 } else { trace[i] = getRand(b) % 32768 } } b.ResetTimer() for i := 0; i < b.N; i++ { l.Add(trace[i], trace[i]) } var hit, miss int for i := 0; i < b.N; i++ { if _, ok := l.Get(trace[i]); ok { hit++ } else { miss++ } } b.Logf("hit: %d miss: %d ratio: %f", hit, miss, float64(hit)/float64(hit+miss)) } func BenchmarkLRU_Rand_WithExpire(b *testing.B) { l := NewLRU[int64, int64](8192, nil, time.Millisecond*10) trace := make([]int64, b.N*2) for i := 0; i < b.N*2; i++ { trace[i] = getRand(b) % 32768 } b.ResetTimer() var hit, miss int for i := 0; i < 2*b.N; i++ { if i%2 == 0 { l.Add(trace[i], trace[i]) } else { if _, ok := l.Get(trace[i]); ok { hit++ } else { miss++ } } } b.Logf("hit: %d miss: %d ratio: %f", hit, miss, float64(hit)/float64(hit+miss)) } func BenchmarkLRU_Freq_WithExpire(b *testing.B) { l := NewLRU[int64, int64](8192, nil, time.Millisecond*10) trace := make([]int64, b.N*2) for i := 0; i < b.N*2; i++ { if i%2 == 0 { trace[i] = getRand(b) % 16384 } else { trace[i] = getRand(b) % 32768 } } b.ResetTimer() for i := 0; i < b.N; i++ { l.Add(trace[i], trace[i]) } var hit, miss int for i := 0; i < b.N; i++ { if _, ok := l.Get(trace[i]); ok { hit++ } else { miss++ } } b.Logf("hit: %d miss: %d ratio: %f", hit, miss, float64(hit)/float64(hit+miss)) } func TestLRUInterface(_ *testing.T) { var _ simplelru.LRUCache[int, int] = &LRU[int, int]{} } func TestLRUNoPurge(t *testing.T) { lc := NewLRU[string, string](10, nil, 0) lc.Add("key1", "val1") if lc.Len() != 1 { t.Fatalf("length differs from expected") } v, ok := lc.Peek("key1") if v != "val1" { t.Fatalf("value differs from expected") } if !ok { t.Fatalf("should be true") } if !lc.Contains("key1") { t.Fatalf("should contain key1") } if lc.Contains("key2") { t.Fatalf("should not contain key2") } v, ok = lc.Peek("key2") if v != "" { t.Fatalf("should be empty") } if ok { t.Fatalf("should be false") } if !reflect.DeepEqual(lc.Keys(), []string{"key1"}) { t.Fatalf("value differs from expected") } if lc.Resize(0) != 0 { t.Fatalf("evicted count differs from expected") } if lc.Resize(2) != 0 { t.Fatalf("evicted count differs from expected") } lc.Add("key2", "val2") if lc.Resize(1) != 1 { t.Fatalf("evicted count differs from expected") } } func TestLRUEdgeCases(t *testing.T) { lc := NewLRU[string, *string](2, nil, 0) // Adding a nil value lc.Add("key1", nil) value, exists := lc.Get("key1") if value != nil || !exists { t.Fatalf("unexpected value or existence flag for key1: value=%v, exists=%v", value, exists) } // Adding an entry with the same key but different value newVal := "val1" lc.Add("key1", &newVal) value, exists = lc.Get("key1") if value != &newVal || !exists { t.Fatalf("unexpected value or existence flag for key1: value=%v, exists=%v", value, exists) } } func TestLRU_Values(t *testing.T) { lc := NewLRU[string, string](3, nil, 0) lc.Add("key1", "val1") lc.Add("key2", "val2") lc.Add("key3", "val3") values := lc.Values() if !reflect.DeepEqual(values, []string{"val1", "val2", "val3"}) { t.Fatalf("values differs from expected") } } // func TestExpirableMultipleClose(_ *testing.T) { // lc := NewLRU[string, string](10, nil, 0) // lc.Close() // // should not panic // lc.Close() // } func TestLRUWithPurge(t *testing.T) { var evicted []string lc := NewLRU(10, func(key string, value string) { evicted = append(evicted, key, value) }, 150*time.Millisecond) k, v, ok := lc.GetOldest() if k != "" { t.Fatalf("should be empty") } if v != "" { t.Fatalf("should be empty") } if ok { t.Fatalf("should be false") } lc.Add("key1", "val1") time.Sleep(100 * time.Millisecond) // not enough to expire if lc.Len() != 1 { t.Fatalf("length differs from expected") } v, ok = lc.Get("key1") if v != "val1" { t.Fatalf("value differs from expected") } if !ok { t.Fatalf("should be true") } time.Sleep(200 * time.Millisecond) // expire v, ok = lc.Get("key1") if ok { t.Fatalf("should be false") } if v != "" { t.Fatalf("should be nil") } if lc.Len() != 0 { t.Fatalf("length differs from expected") } if !reflect.DeepEqual(evicted, []string{"key1", "val1"}) { t.Fatalf("value differs from expected") } // add new entry lc.Add("key2", "val2") if lc.Len() != 1 { t.Fatalf("length differs from expected") } k, v, ok = lc.GetOldest() if k != "key2" { t.Fatalf("value differs from expected") } if v != "val2" { t.Fatalf("value differs from expected") } if !ok { t.Fatalf("should be true") } // DeleteExpired, nothing deleted lc.deleteExpired() if lc.Len() != 1 { t.Fatalf("length differs from expected") } if !reflect.DeepEqual(evicted, []string{"key1", "val1"}) { t.Fatalf("value differs from expected") } // Purge, cache should be clean lc.Purge() if lc.Len() != 0 { t.Fatalf("length differs from expected") } if !reflect.DeepEqual(evicted, []string{"key1", "val1", "key2", "val2"}) { t.Fatalf("value differs from expected") } } func TestLRUWithPurgeEnforcedBySize(t *testing.T) { lc := NewLRU[string, string](10, nil, time.Hour) for i := 0; i < 100; i++ { i := i lc.Add(fmt.Sprintf("key%d", i), fmt.Sprintf("val%d", i)) v, ok := lc.Get(fmt.Sprintf("key%d", i)) if v != fmt.Sprintf("val%d", i) { t.Fatalf("value differs from expected") } if !ok { t.Fatalf("should be true") } if lc.Len() > 20 { t.Fatalf("length should be less than 20") } } if lc.Len() != 10 { t.Fatalf("length differs from expected") } } func TestLRUConcurrency(t *testing.T) { lc := NewLRU[string, string](0, nil, 0) wg := sync.WaitGroup{} wg.Add(1000) for i := 0; i < 1000; i++ { go func(i int) { lc.Add(fmt.Sprintf("key-%d", i/10), fmt.Sprintf("val-%d", i/10)) wg.Done() }(i) } wg.Wait() if lc.Len() != 100 { t.Fatalf("length differs from expected") } } func TestLRUInvalidateAndEvict(t *testing.T) { var evicted int lc := NewLRU(-1, func(_, _ string) { evicted++ }, 0) lc.Add("key1", "val1") lc.Add("key2", "val2") val, ok := lc.Get("key1") if !ok { t.Fatalf("should be true") } if val != "val1" { t.Fatalf("value differs from expected") } if evicted != 0 { t.Fatalf("value differs from expected") } lc.Remove("key1") if evicted != 1 { t.Fatalf("value differs from expected") } val, ok = lc.Get("key1") if val != "" { t.Fatalf("should be empty") } if ok { t.Fatalf("should be false") } } func TestLoadingExpired(t *testing.T) { lc := NewLRU[string, string](0, nil, time.Millisecond*5) lc.Add("key1", "val1") if lc.Len() != 1 { t.Fatalf("length differs from expected") } v, ok := lc.Peek("key1") if v != "val1" { t.Fatalf("value differs from expected") } if !ok { t.Fatalf("should be true") } v, ok = lc.Get("key1") if v != "val1" { t.Fatalf("value differs from expected") } if !ok { t.Fatalf("should be true") } for { result, ok := lc.Get("key1") if ok && result == "" { t.Fatalf("ok should return a result") } if !ok { break } } time.Sleep(time.Millisecond * 100) // wait for expiration reaper if lc.Len() != 0 { t.Fatalf("length differs from expected") } v, ok = lc.Peek("key1") if v != "" { t.Fatalf("should be empty") } if ok { t.Fatalf("should be false") } v, ok = lc.Get("key1") if v != "" { t.Fatalf("should be empty") } if ok { t.Fatalf("should be false") } } func TestLRURemoveOldest(t *testing.T) { lc := NewLRU[string, string](2, nil, 0) k, v, ok := lc.RemoveOldest() if k != "" { t.Fatalf("should be empty") } if v != "" { t.Fatalf("should be empty") } if ok { t.Fatalf("should be false") } ok = lc.Remove("non_existent") if ok { t.Fatalf("should be false") } lc.Add("key1", "val1") if lc.Len() != 1 { t.Fatalf("length differs from expected") } v, ok = lc.Get("key1") if !ok { t.Fatalf("should be true") } if v != "val1" { t.Fatalf("value differs from expected") } if !reflect.DeepEqual(lc.Keys(), []string{"key1"}) { t.Fatalf("value differs from expected") } if lc.Len() != 1 { t.Fatalf("length differs from expected") } lc.Add("key2", "val2") if !reflect.DeepEqual(lc.Keys(), []string{"key1", "key2"}) { t.Fatalf("value differs from expected") } if lc.Len() != 2 { t.Fatalf("length differs from expected") } k, v, ok = lc.RemoveOldest() if k != "key1" { t.Fatalf("value differs from expected") } if v != "val1" { t.Fatalf("value differs from expected") } if !ok { t.Fatalf("should be true") } if !reflect.DeepEqual(lc.Keys(), []string{"key2"}) { t.Fatalf("value differs from expected") } if lc.Len() != 1 { t.Fatalf("length differs from expected") } } func ExampleLRU() { // make cache with 10ms TTL and 5 max keys cache := NewLRU[string, string](5, nil, time.Millisecond*10) // set value under key1. cache.Add("key1", "val1") // get value under key1 r, ok := cache.Get("key1") // check for OK value if ok { fmt.Printf("value before expiration is found: %v, value: %q\n", ok, r) } // wait for cache to expire time.Sleep(time.Millisecond * 100) // get value under key1 after key expiration r, ok = cache.Get("key1") fmt.Printf("value after expiration is found: %v, value: %q\n", ok, r) // set value under key2, would evict old entry because it is already expired. cache.Add("key2", "val2") fmt.Printf("Cache len: %d\n", cache.Len()) // Output: // value before expiration is found: true, value: "val1" // value after expiration is found: false, value: "" // Cache len: 1 } func getRand(tb testing.TB) int64 { out, err := rand.Int(rand.Reader, big.NewInt(math.MaxInt64)) if err != nil { tb.Fatal(err) } return out.Int64() } func (c *LRU[K, V]) wantKeys(t *testing.T, want []K) { t.Helper() got := c.Keys() if !reflect.DeepEqual(got, want) { t.Errorf("wrong keys got: %v, want: %v ", got, want) } } func TestCache_EvictionSameKey(t *testing.T) { var evictedKeys []int cache := NewLRU[int, struct{}]( 2, func(key int, _ struct{}) { evictedKeys = append(evictedKeys, key) }, 0) if evicted := cache.Add(1, struct{}{}); evicted { t.Error("First 1: got unexpected eviction") } cache.wantKeys(t, []int{1}) if evicted := cache.Add(2, struct{}{}); evicted { t.Error("2: got unexpected eviction") } cache.wantKeys(t, []int{1, 2}) if evicted := cache.Add(1, struct{}{}); evicted { t.Error("Second 1: got unexpected eviction") } cache.wantKeys(t, []int{2, 1}) if evicted := cache.Add(3, struct{}{}); !evicted { t.Error("3: did not get expected eviction") } cache.wantKeys(t, []int{1, 3}) want := []int{2} if !reflect.DeepEqual(evictedKeys, want) { t.Errorf("evictedKeys got: %v want: %v", evictedKeys, want) } } golang-lru-arc-v2.0.7/go.mod000066400000000000000000000000631450557771600156460ustar00rootroot00000000000000module github.com/hashicorp/golang-lru/v2 go 1.18 golang-lru-arc-v2.0.7/internal/000077500000000000000000000000001450557771600163555ustar00rootroot00000000000000golang-lru-arc-v2.0.7/internal/list.go000066400000000000000000000075131450557771600176650ustar00rootroot00000000000000// Copyright 2009 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE_list file. package internal import "time" // Entry is an LRU Entry type Entry[K comparable, V any] struct { // Next and previous pointers in the doubly-linked list of elements. // To simplify the implementation, internally a list l is implemented // as a ring, such that &l.root is both the next element of the last // list element (l.Back()) and the previous element of the first list // element (l.Front()). next, prev *Entry[K, V] // The list to which this element belongs. list *LruList[K, V] // The LRU Key of this element. Key K // The Value stored with this element. Value V // The time this element would be cleaned up, optional ExpiresAt time.Time // The expiry bucket item was put in, optional ExpireBucket uint8 } // PrevEntry returns the previous list element or nil. func (e *Entry[K, V]) PrevEntry() *Entry[K, V] { if p := e.prev; e.list != nil && p != &e.list.root { return p } return nil } // LruList represents a doubly linked list. // The zero Value for LruList is an empty list ready to use. type LruList[K comparable, V any] struct { root Entry[K, V] // sentinel list element, only &root, root.prev, and root.next are used len int // current list Length excluding (this) sentinel element } // Init initializes or clears list l. func (l *LruList[K, V]) Init() *LruList[K, V] { l.root.next = &l.root l.root.prev = &l.root l.len = 0 return l } // NewList returns an initialized list. func NewList[K comparable, V any]() *LruList[K, V] { return new(LruList[K, V]).Init() } // Length returns the number of elements of list l. // The complexity is O(1). func (l *LruList[K, V]) Length() int { return l.len } // Back returns the last element of list l or nil if the list is empty. func (l *LruList[K, V]) Back() *Entry[K, V] { if l.len == 0 { return nil } return l.root.prev } // lazyInit lazily initializes a zero List Value. func (l *LruList[K, V]) lazyInit() { if l.root.next == nil { l.Init() } } // insert inserts e after at, increments l.len, and returns e. func (l *LruList[K, V]) insert(e, at *Entry[K, V]) *Entry[K, V] { e.prev = at e.next = at.next e.prev.next = e e.next.prev = e e.list = l l.len++ return e } // insertValue is a convenience wrapper for insert(&Entry{Value: v, ExpiresAt: ExpiresAt}, at). func (l *LruList[K, V]) insertValue(k K, v V, expiresAt time.Time, at *Entry[K, V]) *Entry[K, V] { return l.insert(&Entry[K, V]{Value: v, Key: k, ExpiresAt: expiresAt}, at) } // Remove removes e from its list, decrements l.len func (l *LruList[K, V]) Remove(e *Entry[K, V]) V { e.prev.next = e.next e.next.prev = e.prev e.next = nil // avoid memory leaks e.prev = nil // avoid memory leaks e.list = nil l.len-- return e.Value } // move moves e to next to at. func (l *LruList[K, V]) move(e, at *Entry[K, V]) { if e == at { return } e.prev.next = e.next e.next.prev = e.prev e.prev = at e.next = at.next e.prev.next = e e.next.prev = e } // PushFront inserts a new element e with value v at the front of list l and returns e. func (l *LruList[K, V]) PushFront(k K, v V) *Entry[K, V] { l.lazyInit() return l.insertValue(k, v, time.Time{}, &l.root) } // PushFrontExpirable inserts a new expirable element e with Value v at the front of list l and returns e. func (l *LruList[K, V]) PushFrontExpirable(k K, v V, expiresAt time.Time) *Entry[K, V] { l.lazyInit() return l.insertValue(k, v, expiresAt, &l.root) } // MoveToFront moves element e to the front of list l. // If e is not an element of l, the list is not modified. // The element must not be nil. func (l *LruList[K, V]) MoveToFront(e *Entry[K, V]) { if e.list != l || l.root.next == e { return } // see comment in List.Remove about initialization of l l.move(e, &l.root) } golang-lru-arc-v2.0.7/lru.go000066400000000000000000000142641450557771600157010ustar00rootroot00000000000000// Copyright (c) HashiCorp, Inc. // SPDX-License-Identifier: MPL-2.0 package lru import ( "sync" "github.com/hashicorp/golang-lru/v2/simplelru" ) const ( // DefaultEvictedBufferSize defines the default buffer size to store evicted key/val DefaultEvictedBufferSize = 16 ) // Cache is a thread-safe fixed size LRU cache. type Cache[K comparable, V any] struct { lru *simplelru.LRU[K, V] evictedKeys []K evictedVals []V onEvictedCB func(k K, v V) lock sync.RWMutex } // New creates an LRU of the given size. func New[K comparable, V any](size int) (*Cache[K, V], error) { return NewWithEvict[K, V](size, nil) } // NewWithEvict constructs a fixed size cache with the given eviction // callback. func NewWithEvict[K comparable, V any](size int, onEvicted func(key K, value V)) (c *Cache[K, V], err error) { // create a cache with default settings c = &Cache[K, V]{ onEvictedCB: onEvicted, } if onEvicted != nil { c.initEvictBuffers() onEvicted = c.onEvicted } c.lru, err = simplelru.NewLRU(size, onEvicted) return } func (c *Cache[K, V]) initEvictBuffers() { c.evictedKeys = make([]K, 0, DefaultEvictedBufferSize) c.evictedVals = make([]V, 0, DefaultEvictedBufferSize) } // onEvicted save evicted key/val and sent in externally registered callback // outside of critical section func (c *Cache[K, V]) onEvicted(k K, v V) { c.evictedKeys = append(c.evictedKeys, k) c.evictedVals = append(c.evictedVals, v) } // Purge is used to completely clear the cache. func (c *Cache[K, V]) Purge() { var ks []K var vs []V c.lock.Lock() c.lru.Purge() if c.onEvictedCB != nil && len(c.evictedKeys) > 0 { ks, vs = c.evictedKeys, c.evictedVals c.initEvictBuffers() } c.lock.Unlock() // invoke callback outside of critical section if c.onEvictedCB != nil { for i := 0; i < len(ks); i++ { c.onEvictedCB(ks[i], vs[i]) } } } // Add adds a value to the cache. Returns true if an eviction occurred. func (c *Cache[K, V]) Add(key K, value V) (evicted bool) { var k K var v V c.lock.Lock() evicted = c.lru.Add(key, value) if c.onEvictedCB != nil && evicted { k, v = c.evictedKeys[0], c.evictedVals[0] c.evictedKeys, c.evictedVals = c.evictedKeys[:0], c.evictedVals[:0] } c.lock.Unlock() if c.onEvictedCB != nil && evicted { c.onEvictedCB(k, v) } return } // Get looks up a key's value from the cache. func (c *Cache[K, V]) Get(key K) (value V, ok bool) { c.lock.Lock() value, ok = c.lru.Get(key) c.lock.Unlock() return value, ok } // Contains checks if a key is in the cache, without updating the // recent-ness or deleting it for being stale. func (c *Cache[K, V]) Contains(key K) bool { c.lock.RLock() containKey := c.lru.Contains(key) c.lock.RUnlock() return containKey } // Peek returns the key value (or undefined if not found) without updating // the "recently used"-ness of the key. func (c *Cache[K, V]) Peek(key K) (value V, ok bool) { c.lock.RLock() value, ok = c.lru.Peek(key) c.lock.RUnlock() return value, ok } // ContainsOrAdd checks if a key is in the cache without updating the // recent-ness or deleting it for being stale, and if not, adds the value. // Returns whether found and whether an eviction occurred. func (c *Cache[K, V]) ContainsOrAdd(key K, value V) (ok, evicted bool) { var k K var v V c.lock.Lock() if c.lru.Contains(key) { c.lock.Unlock() return true, false } evicted = c.lru.Add(key, value) if c.onEvictedCB != nil && evicted { k, v = c.evictedKeys[0], c.evictedVals[0] c.evictedKeys, c.evictedVals = c.evictedKeys[:0], c.evictedVals[:0] } c.lock.Unlock() if c.onEvictedCB != nil && evicted { c.onEvictedCB(k, v) } return false, evicted } // PeekOrAdd checks if a key is in the cache without updating the // recent-ness or deleting it for being stale, and if not, adds the value. // Returns whether found and whether an eviction occurred. func (c *Cache[K, V]) PeekOrAdd(key K, value V) (previous V, ok, evicted bool) { var k K var v V c.lock.Lock() previous, ok = c.lru.Peek(key) if ok { c.lock.Unlock() return previous, true, false } evicted = c.lru.Add(key, value) if c.onEvictedCB != nil && evicted { k, v = c.evictedKeys[0], c.evictedVals[0] c.evictedKeys, c.evictedVals = c.evictedKeys[:0], c.evictedVals[:0] } c.lock.Unlock() if c.onEvictedCB != nil && evicted { c.onEvictedCB(k, v) } return } // Remove removes the provided key from the cache. func (c *Cache[K, V]) Remove(key K) (present bool) { var k K var v V c.lock.Lock() present = c.lru.Remove(key) if c.onEvictedCB != nil && present { k, v = c.evictedKeys[0], c.evictedVals[0] c.evictedKeys, c.evictedVals = c.evictedKeys[:0], c.evictedVals[:0] } c.lock.Unlock() if c.onEvictedCB != nil && present { c.onEvictedCB(k, v) } return } // Resize changes the cache size. func (c *Cache[K, V]) Resize(size int) (evicted int) { var ks []K var vs []V c.lock.Lock() evicted = c.lru.Resize(size) if c.onEvictedCB != nil && evicted > 0 { ks, vs = c.evictedKeys, c.evictedVals c.initEvictBuffers() } c.lock.Unlock() if c.onEvictedCB != nil && evicted > 0 { for i := 0; i < len(ks); i++ { c.onEvictedCB(ks[i], vs[i]) } } return evicted } // RemoveOldest removes the oldest item from the cache. func (c *Cache[K, V]) RemoveOldest() (key K, value V, ok bool) { var k K var v V c.lock.Lock() key, value, ok = c.lru.RemoveOldest() if c.onEvictedCB != nil && ok { k, v = c.evictedKeys[0], c.evictedVals[0] c.evictedKeys, c.evictedVals = c.evictedKeys[:0], c.evictedVals[:0] } c.lock.Unlock() if c.onEvictedCB != nil && ok { c.onEvictedCB(k, v) } return } // GetOldest returns the oldest entry func (c *Cache[K, V]) GetOldest() (key K, value V, ok bool) { c.lock.RLock() key, value, ok = c.lru.GetOldest() c.lock.RUnlock() return } // Keys returns a slice of the keys in the cache, from oldest to newest. func (c *Cache[K, V]) Keys() []K { c.lock.RLock() keys := c.lru.Keys() c.lock.RUnlock() return keys } // Values returns a slice of the values in the cache, from oldest to newest. func (c *Cache[K, V]) Values() []V { c.lock.RLock() values := c.lru.Values() c.lock.RUnlock() return values } // Len returns the number of items in the cache. func (c *Cache[K, V]) Len() int { c.lock.RLock() length := c.lru.Len() c.lock.RUnlock() return length } golang-lru-arc-v2.0.7/lru_test.go000066400000000000000000000220271450557771600167340ustar00rootroot00000000000000// Copyright (c) HashiCorp, Inc. // SPDX-License-Identifier: MPL-2.0 package lru import ( "reflect" "testing" ) func BenchmarkLRU_Rand(b *testing.B) { l, err := New[int64, int64](8192) if err != nil { b.Fatalf("err: %v", err) } trace := make([]int64, b.N*2) for i := 0; i < b.N*2; i++ { trace[i] = getRand(b) % 32768 } b.ResetTimer() var hit, miss int for i := 0; i < 2*b.N; i++ { if i%2 == 0 { l.Add(trace[i], trace[i]) } else { if _, ok := l.Get(trace[i]); ok { hit++ } else { miss++ } } } b.Logf("hit: %d miss: %d ratio: %f", hit, miss, float64(hit)/float64(hit+miss)) } func BenchmarkLRU_Freq(b *testing.B) { l, err := New[int64, int64](8192) if err != nil { b.Fatalf("err: %v", err) } trace := make([]int64, b.N*2) for i := 0; i < b.N*2; i++ { if i%2 == 0 { trace[i] = getRand(b) % 16384 } else { trace[i] = getRand(b) % 32768 } } b.ResetTimer() for i := 0; i < b.N; i++ { l.Add(trace[i], trace[i]) } var hit, miss int for i := 0; i < b.N; i++ { if _, ok := l.Get(trace[i]); ok { hit++ } else { miss++ } } b.Logf("hit: %d miss: %d ratio: %f", hit, miss, float64(hit)/float64(hit+miss)) } func TestLRU(t *testing.T) { evictCounter := 0 onEvicted := func(k int, v int) { if k != v { t.Fatalf("Evict values not equal (%v!=%v)", k, v) } evictCounter++ } l, err := NewWithEvict(128, onEvicted) if err != nil { t.Fatalf("err: %v", err) } for i := 0; i < 256; i++ { l.Add(i, i) } if l.Len() != 128 { t.Fatalf("bad len: %v", l.Len()) } if evictCounter != 128 { t.Fatalf("bad evict count: %v", evictCounter) } for i, k := range l.Keys() { if v, ok := l.Get(k); !ok || v != k || v != i+128 { t.Fatalf("bad key: %v", k) } } for i, v := range l.Values() { if v != i+128 { t.Fatalf("bad value: %v", v) } } for i := 0; i < 128; i++ { if _, ok := l.Get(i); ok { t.Fatalf("should be evicted") } } for i := 128; i < 256; i++ { if _, ok := l.Get(i); !ok { t.Fatalf("should not be evicted") } } for i := 128; i < 192; i++ { l.Remove(i) if _, ok := l.Get(i); ok { t.Fatalf("should be deleted") } } l.Get(192) // expect 192 to be last key in l.Keys() for i, k := range l.Keys() { if (i < 63 && k != i+193) || (i == 63 && k != 192) { t.Fatalf("out of order key: %v", k) } } l.Purge() if l.Len() != 0 { t.Fatalf("bad len: %v", l.Len()) } if _, ok := l.Get(200); ok { t.Fatalf("should contain nothing") } } // test that Add returns true/false if an eviction occurred func TestLRUAdd(t *testing.T) { evictCounter := 0 onEvicted := func(k int, v int) { evictCounter++ } l, err := NewWithEvict(1, onEvicted) if err != nil { t.Fatalf("err: %v", err) } if l.Add(1, 1) == true || evictCounter != 0 { t.Errorf("should not have an eviction") } if l.Add(2, 2) == false || evictCounter != 1 { t.Errorf("should have an eviction") } } // test that Contains doesn't update recent-ness func TestLRUContains(t *testing.T) { l, err := New[int, int](2) if err != nil { t.Fatalf("err: %v", err) } l.Add(1, 1) l.Add(2, 2) if !l.Contains(1) { t.Errorf("1 should be contained") } l.Add(3, 3) if l.Contains(1) { t.Errorf("Contains should not have updated recent-ness of 1") } } // test that ContainsOrAdd doesn't update recent-ness func TestLRUContainsOrAdd(t *testing.T) { l, err := New[int, int](2) if err != nil { t.Fatalf("err: %v", err) } l.Add(1, 1) l.Add(2, 2) contains, evict := l.ContainsOrAdd(1, 1) if !contains { t.Errorf("1 should be contained") } if evict { t.Errorf("nothing should be evicted here") } l.Add(3, 3) contains, evict = l.ContainsOrAdd(1, 1) if contains { t.Errorf("1 should not have been contained") } if !evict { t.Errorf("an eviction should have occurred") } if !l.Contains(1) { t.Errorf("now 1 should be contained") } } // test that PeekOrAdd doesn't update recent-ness func TestLRUPeekOrAdd(t *testing.T) { l, err := New[int, int](2) if err != nil { t.Fatalf("err: %v", err) } l.Add(1, 1) l.Add(2, 2) previous, contains, evict := l.PeekOrAdd(1, 1) if !contains { t.Errorf("1 should be contained") } if evict { t.Errorf("nothing should be evicted here") } if previous != 1 { t.Errorf("previous is not equal to 1") } l.Add(3, 3) contains, evict = l.ContainsOrAdd(1, 1) if contains { t.Errorf("1 should not have been contained") } if !evict { t.Errorf("an eviction should have occurred") } if !l.Contains(1) { t.Errorf("now 1 should be contained") } } // test that Peek doesn't update recent-ness func TestLRUPeek(t *testing.T) { l, err := New[int, int](2) if err != nil { t.Fatalf("err: %v", err) } l.Add(1, 1) l.Add(2, 2) if v, ok := l.Peek(1); !ok || v != 1 { t.Errorf("1 should be set to 1: %v, %v", v, ok) } l.Add(3, 3) if l.Contains(1) { t.Errorf("should not have updated recent-ness of 1") } } // test that Resize can upsize and downsize func TestLRUResize(t *testing.T) { onEvictCounter := 0 onEvicted := func(k int, v int) { onEvictCounter++ } l, err := NewWithEvict(2, onEvicted) if err != nil { t.Fatalf("err: %v", err) } // Downsize l.Add(1, 1) l.Add(2, 2) evicted := l.Resize(1) if evicted != 1 { t.Errorf("1 element should have been evicted: %v", evicted) } if onEvictCounter != 1 { t.Errorf("onEvicted should have been called 1 time: %v", onEvictCounter) } l.Add(3, 3) if l.Contains(1) { t.Errorf("Element 1 should have been evicted") } // Upsize evicted = l.Resize(2) if evicted != 0 { t.Errorf("0 elements should have been evicted: %v", evicted) } l.Add(4, 4) if !l.Contains(3) || !l.Contains(4) { t.Errorf("Cache should have contained 2 elements") } } func (c *Cache[K, V]) wantKeys(t *testing.T, want []K) { t.Helper() got := c.Keys() if !reflect.DeepEqual(got, want) { t.Errorf("wrong keys got: %v, want: %v ", got, want) } } func TestCache_EvictionSameKey(t *testing.T) { t.Run("Add", func(t *testing.T) { var evictedKeys []int cache, _ := NewWithEvict( 2, func(key int, _ struct{}) { evictedKeys = append(evictedKeys, key) }) if evicted := cache.Add(1, struct{}{}); evicted { t.Error("First 1: got unexpected eviction") } cache.wantKeys(t, []int{1}) if evicted := cache.Add(2, struct{}{}); evicted { t.Error("2: got unexpected eviction") } cache.wantKeys(t, []int{1, 2}) if evicted := cache.Add(1, struct{}{}); evicted { t.Error("Second 1: got unexpected eviction") } cache.wantKeys(t, []int{2, 1}) if evicted := cache.Add(3, struct{}{}); !evicted { t.Error("3: did not get expected eviction") } cache.wantKeys(t, []int{1, 3}) want := []int{2} if !reflect.DeepEqual(evictedKeys, want) { t.Errorf("evictedKeys got: %v want: %v", evictedKeys, want) } }) t.Run("ContainsOrAdd", func(t *testing.T) { var evictedKeys []int cache, _ := NewWithEvict( 2, func(key int, _ struct{}) { evictedKeys = append(evictedKeys, key) }) contained, evicted := cache.ContainsOrAdd(1, struct{}{}) if contained { t.Error("First 1: got unexpected contained") } if evicted { t.Error("First 1: got unexpected eviction") } cache.wantKeys(t, []int{1}) contained, evicted = cache.ContainsOrAdd(2, struct{}{}) if contained { t.Error("2: got unexpected contained") } if evicted { t.Error("2: got unexpected eviction") } cache.wantKeys(t, []int{1, 2}) contained, evicted = cache.ContainsOrAdd(1, struct{}{}) if !contained { t.Error("Second 1: did not get expected contained") } if evicted { t.Error("Second 1: got unexpected eviction") } cache.wantKeys(t, []int{1, 2}) contained, evicted = cache.ContainsOrAdd(3, struct{}{}) if contained { t.Error("3: got unexpected contained") } if !evicted { t.Error("3: did not get expected eviction") } cache.wantKeys(t, []int{2, 3}) want := []int{1} if !reflect.DeepEqual(evictedKeys, want) { t.Errorf("evictedKeys got: %v want: %v", evictedKeys, want) } }) t.Run("PeekOrAdd", func(t *testing.T) { var evictedKeys []int cache, _ := NewWithEvict( 2, func(key int, _ struct{}) { evictedKeys = append(evictedKeys, key) }) _, contained, evicted := cache.PeekOrAdd(1, struct{}{}) if contained { t.Error("First 1: got unexpected contained") } if evicted { t.Error("First 1: got unexpected eviction") } cache.wantKeys(t, []int{1}) _, contained, evicted = cache.PeekOrAdd(2, struct{}{}) if contained { t.Error("2: got unexpected contained") } if evicted { t.Error("2: got unexpected eviction") } cache.wantKeys(t, []int{1, 2}) _, contained, evicted = cache.PeekOrAdd(1, struct{}{}) if !contained { t.Error("Second 1: did not get expected contained") } if evicted { t.Error("Second 1: got unexpected eviction") } cache.wantKeys(t, []int{1, 2}) _, contained, evicted = cache.PeekOrAdd(3, struct{}{}) if contained { t.Error("3: got unexpected contained") } if !evicted { t.Error("3: did not get expected eviction") } cache.wantKeys(t, []int{2, 3}) want := []int{1} if !reflect.DeepEqual(evictedKeys, want) { t.Errorf("evictedKeys got: %v want: %v", evictedKeys, want) } }) } golang-lru-arc-v2.0.7/simplelru/000077500000000000000000000000001450557771600165555ustar00rootroot00000000000000golang-lru-arc-v2.0.7/simplelru/LICENSE_list000066400000000000000000000027621450557771600206240ustar00rootroot00000000000000This license applies to simplelru/list.go Copyright (c) 2009 The Go Authors. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. * Neither the name of Google Inc. nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. golang-lru-arc-v2.0.7/simplelru/lru.go000066400000000000000000000101121450557771600177010ustar00rootroot00000000000000// Copyright (c) HashiCorp, Inc. // SPDX-License-Identifier: MPL-2.0 package simplelru import ( "errors" "github.com/hashicorp/golang-lru/v2/internal" ) // EvictCallback is used to get a callback when a cache entry is evicted type EvictCallback[K comparable, V any] func(key K, value V) // LRU implements a non-thread safe fixed size LRU cache type LRU[K comparable, V any] struct { size int evictList *internal.LruList[K, V] items map[K]*internal.Entry[K, V] onEvict EvictCallback[K, V] } // NewLRU constructs an LRU of the given size func NewLRU[K comparable, V any](size int, onEvict EvictCallback[K, V]) (*LRU[K, V], error) { if size <= 0 { return nil, errors.New("must provide a positive size") } c := &LRU[K, V]{ size: size, evictList: internal.NewList[K, V](), items: make(map[K]*internal.Entry[K, V]), onEvict: onEvict, } return c, nil } // Purge is used to completely clear the cache. func (c *LRU[K, V]) Purge() { for k, v := range c.items { if c.onEvict != nil { c.onEvict(k, v.Value) } delete(c.items, k) } c.evictList.Init() } // Add adds a value to the cache. Returns true if an eviction occurred. func (c *LRU[K, V]) Add(key K, value V) (evicted bool) { // Check for existing item if ent, ok := c.items[key]; ok { c.evictList.MoveToFront(ent) ent.Value = value return false } // Add new item ent := c.evictList.PushFront(key, value) c.items[key] = ent evict := c.evictList.Length() > c.size // Verify size not exceeded if evict { c.removeOldest() } return evict } // Get looks up a key's value from the cache. func (c *LRU[K, V]) Get(key K) (value V, ok bool) { if ent, ok := c.items[key]; ok { c.evictList.MoveToFront(ent) return ent.Value, true } return } // Contains checks if a key is in the cache, without updating the recent-ness // or deleting it for being stale. func (c *LRU[K, V]) Contains(key K) (ok bool) { _, ok = c.items[key] return ok } // Peek returns the key value (or undefined if not found) without updating // the "recently used"-ness of the key. func (c *LRU[K, V]) Peek(key K) (value V, ok bool) { var ent *internal.Entry[K, V] if ent, ok = c.items[key]; ok { return ent.Value, true } return } // Remove removes the provided key from the cache, returning if the // key was contained. func (c *LRU[K, V]) Remove(key K) (present bool) { if ent, ok := c.items[key]; ok { c.removeElement(ent) return true } return false } // RemoveOldest removes the oldest item from the cache. func (c *LRU[K, V]) RemoveOldest() (key K, value V, ok bool) { if ent := c.evictList.Back(); ent != nil { c.removeElement(ent) return ent.Key, ent.Value, true } return } // GetOldest returns the oldest entry func (c *LRU[K, V]) GetOldest() (key K, value V, ok bool) { if ent := c.evictList.Back(); ent != nil { return ent.Key, ent.Value, true } return } // Keys returns a slice of the keys in the cache, from oldest to newest. func (c *LRU[K, V]) Keys() []K { keys := make([]K, c.evictList.Length()) i := 0 for ent := c.evictList.Back(); ent != nil; ent = ent.PrevEntry() { keys[i] = ent.Key i++ } return keys } // Values returns a slice of the values in the cache, from oldest to newest. func (c *LRU[K, V]) Values() []V { values := make([]V, len(c.items)) i := 0 for ent := c.evictList.Back(); ent != nil; ent = ent.PrevEntry() { values[i] = ent.Value i++ } return values } // Len returns the number of items in the cache. func (c *LRU[K, V]) Len() int { return c.evictList.Length() } // Resize changes the cache size. func (c *LRU[K, V]) Resize(size int) (evicted int) { diff := c.Len() - size if diff < 0 { diff = 0 } for i := 0; i < diff; i++ { c.removeOldest() } c.size = size return diff } // removeOldest removes the oldest item from the cache. func (c *LRU[K, V]) removeOldest() { if ent := c.evictList.Back(); ent != nil { c.removeElement(ent) } } // removeElement is used to remove a given list element from the cache func (c *LRU[K, V]) removeElement(e *internal.Entry[K, V]) { c.evictList.Remove(e) delete(c.items, e.Key) if c.onEvict != nil { c.onEvict(e.Key, e.Value) } } golang-lru-arc-v2.0.7/simplelru/lru_interface.go000066400000000000000000000024611450557771600217310ustar00rootroot00000000000000// Copyright (c) HashiCorp, Inc. // SPDX-License-Identifier: MPL-2.0 // Package simplelru provides simple LRU implementation based on build-in container/list. package simplelru // LRUCache is the interface for simple LRU cache. type LRUCache[K comparable, V any] interface { // Adds a value to the cache, returns true if an eviction occurred and // updates the "recently used"-ness of the key. Add(key K, value V) bool // Returns key's value from the cache and // updates the "recently used"-ness of the key. #value, isFound Get(key K) (value V, ok bool) // Checks if a key exists in cache without updating the recent-ness. Contains(key K) (ok bool) // Returns key's value without updating the "recently used"-ness of the key. Peek(key K) (value V, ok bool) // Removes a key from the cache. Remove(key K) bool // Removes the oldest entry from cache. RemoveOldest() (K, V, bool) // Returns the oldest entry from the cache. #key, value, isFound GetOldest() (K, V, bool) // Returns a slice of the keys in the cache, from oldest to newest. Keys() []K // Values returns a slice of the values in the cache, from oldest to newest. Values() []V // Returns the number of items in the cache. Len() int // Clears all cache entries. Purge() // Resizes cache, returning number evicted Resize(int) int } golang-lru-arc-v2.0.7/simplelru/lru_test.go000066400000000000000000000116521450557771600207520ustar00rootroot00000000000000// Copyright (c) HashiCorp, Inc. // SPDX-License-Identifier: MPL-2.0 package simplelru import ( "reflect" "testing" ) func TestLRU(t *testing.T) { evictCounter := 0 onEvicted := func(k int, v int) { if k != v { t.Fatalf("Evict values not equal (%v!=%v)", k, v) } evictCounter++ } l, err := NewLRU(128, onEvicted) if err != nil { t.Fatalf("err: %v", err) } for i := 0; i < 256; i++ { l.Add(i, i) } if l.Len() != 128 { t.Fatalf("bad len: %v", l.Len()) } if evictCounter != 128 { t.Fatalf("bad evict count: %v", evictCounter) } for i, k := range l.Keys() { if v, ok := l.Get(k); !ok || v != k || v != i+128 { t.Fatalf("bad key: %v", k) } } for i, v := range l.Values() { if v != i+128 { t.Fatalf("bad value: %v", v) } } for i := 0; i < 128; i++ { if _, ok := l.Get(i); ok { t.Fatalf("should be evicted") } } for i := 128; i < 256; i++ { if _, ok := l.Get(i); !ok { t.Fatalf("should not be evicted") } } for i := 128; i < 192; i++ { if ok := l.Remove(i); !ok { t.Fatalf("should be contained") } if ok := l.Remove(i); ok { t.Fatalf("should not be contained") } if _, ok := l.Get(i); ok { t.Fatalf("should be deleted") } } l.Get(192) // expect 192 to be last key in l.Keys() for i, k := range l.Keys() { if (i < 63 && k != i+193) || (i == 63 && k != 192) { t.Fatalf("out of order key: %v", k) } } l.Purge() if l.Len() != 0 { t.Fatalf("bad len: %v", l.Len()) } if _, ok := l.Get(200); ok { t.Fatalf("should contain nothing") } } func TestLRU_GetOldest_RemoveOldest(t *testing.T) { l, err := NewLRU[int, int](128, nil) if err != nil { t.Fatalf("err: %v", err) } for i := 0; i < 256; i++ { l.Add(i, i) } k, _, ok := l.GetOldest() if !ok { t.Fatalf("missing") } if k != 128 { t.Fatalf("bad: %v", k) } k, _, ok = l.RemoveOldest() if !ok { t.Fatalf("missing") } if k != 128 { t.Fatalf("bad: %v", k) } k, _, ok = l.RemoveOldest() if !ok { t.Fatalf("missing") } if k != 129 { t.Fatalf("bad: %v", k) } } // Test that Add returns true/false if an eviction occurred func TestLRU_Add(t *testing.T) { evictCounter := 0 onEvicted := func(k int, v int) { evictCounter++ } l, err := NewLRU(1, onEvicted) if err != nil { t.Fatalf("err: %v", err) } if l.Add(1, 1) == true || evictCounter != 0 { t.Errorf("should not have an eviction") } if l.Add(2, 2) == false || evictCounter != 1 { t.Errorf("should have an eviction") } } // Test that Contains doesn't update recent-ness func TestLRU_Contains(t *testing.T) { l, err := NewLRU[int, int](2, nil) if err != nil { t.Fatalf("err: %v", err) } l.Add(1, 1) l.Add(2, 2) if !l.Contains(1) { t.Errorf("1 should be contained") } l.Add(3, 3) if l.Contains(1) { t.Errorf("Contains should not have updated recent-ness of 1") } } // Test that Peek doesn't update recent-ness func TestLRU_Peek(t *testing.T) { l, err := NewLRU[int, int](2, nil) if err != nil { t.Fatalf("err: %v", err) } l.Add(1, 1) l.Add(2, 2) if v, ok := l.Peek(1); !ok || v != 1 { t.Errorf("1 should be set to 1: %v, %v", v, ok) } l.Add(3, 3) if l.Contains(1) { t.Errorf("should not have updated recent-ness of 1") } } // Test that Resize can upsize and downsize func TestLRU_Resize(t *testing.T) { onEvictCounter := 0 onEvicted := func(k int, v int) { onEvictCounter++ } l, err := NewLRU(2, onEvicted) if err != nil { t.Fatalf("err: %v", err) } // Downsize l.Add(1, 1) l.Add(2, 2) evicted := l.Resize(1) if evicted != 1 { t.Errorf("1 element should have been evicted: %v", evicted) } if onEvictCounter != 1 { t.Errorf("onEvicted should have been called 1 time: %v", onEvictCounter) } l.Add(3, 3) if l.Contains(1) { t.Errorf("Element 1 should have been evicted") } // Upsize evicted = l.Resize(2) if evicted != 0 { t.Errorf("0 elements should have been evicted: %v", evicted) } l.Add(4, 4) if !l.Contains(3) || !l.Contains(4) { t.Errorf("Cache should have contained 2 elements") } } func (c *LRU[K, V]) wantKeys(t *testing.T, want []K) { t.Helper() got := c.Keys() if !reflect.DeepEqual(got, want) { t.Errorf("wrong keys got: %v, want: %v ", got, want) } } func TestCache_EvictionSameKey(t *testing.T) { var evictedKeys []int cache, _ := NewLRU( 2, func(key int, _ struct{}) { evictedKeys = append(evictedKeys, key) }) if evicted := cache.Add(1, struct{}{}); evicted { t.Error("First 1: got unexpected eviction") } cache.wantKeys(t, []int{1}) if evicted := cache.Add(2, struct{}{}); evicted { t.Error("2: got unexpected eviction") } cache.wantKeys(t, []int{1, 2}) if evicted := cache.Add(1, struct{}{}); evicted { t.Error("Second 1: got unexpected eviction") } cache.wantKeys(t, []int{2, 1}) if evicted := cache.Add(3, struct{}{}); !evicted { t.Error("3: did not get expected eviction") } cache.wantKeys(t, []int{1, 3}) want := []int{2} if !reflect.DeepEqual(evictedKeys, want) { t.Errorf("evictedKeys got: %v want: %v", evictedKeys, want) } } golang-lru-arc-v2.0.7/testing_test.go000066400000000000000000000004511450557771600176040ustar00rootroot00000000000000// Copyright (c) HashiCorp, Inc. // SPDX-License-Identifier: MPL-2.0 package lru import ( "crypto/rand" "math" "math/big" "testing" ) func getRand(tb testing.TB) int64 { out, err := rand.Int(rand.Reader, big.NewInt(math.MaxInt64)) if err != nil { tb.Fatal(err) } return out.Int64() }