Cache plugin: replace ARC cache with SIEVE

dnscrypt-proxy/plugin_cache.go

@@ -6,8 +6,8 @@ import (
 	"sync"
 	"time"
 
-	lru "github.com/hashicorp/golang-lru"
 	"github.com/miekg/dns"
+	sieve "github.com/opencoff/go-sieve"
 )
 
 const StaleResponseTTL = 30 * time.Second
@@ -19,7 +19,7 @@ type CachedResponse struct {
 
 type CachedResponses struct {
 	sync.RWMutex
-	cache *lru.ARCCache
+	cache *sieve.Sieve[[32]byte, CachedResponse]
 }
 
 var cachedResponses CachedResponses
@@ -75,12 +75,11 @@ func (plugin *PluginCache) Eval(pluginsState *PluginsState, msg *dns.Msg) error
 		cachedResponses.RUnlock()
 		return nil
 	}
-	cachedAny, ok := cachedResponses.cache.Get(cacheKey)
+	cached, ok := cachedResponses.cache.Get(cacheKey)
 	if !ok {
 		cachedResponses.RUnlock()
 		return nil
 	}
-	cached := cachedAny.(CachedResponse)
 	expiration := cached.expiration
 	synth := cached.msg.Copy()
 	cachedResponses.RUnlock()
@@ -151,8 +150,8 @@ func (plugin *PluginCacheResponse) Eval(pluginsState *PluginsState, msg *dns.Msg
 	cachedResponses.Lock()
 	if cachedResponses.cache == nil {
 		var err error
-		cachedResponses.cache, err = lru.NewARC(pluginsState.cacheSize)
+		cachedResponses.cache = sieve.New[[32]byte, CachedResponse](pluginsState.cacheSize)
-		if err != nil {
+		if cachedResponses.cache == nil {
 			cachedResponses.Unlock()
 			return err
 		}

go.mod

@@ -8,7 +8,6 @@ require (
 	github.com/coreos/go-systemd v0.0.0-20191104093116-d3cd4ed1dbcf
 	github.com/dchest/safefile v0.0.0-20151022103144-855e8d98f185
 	github.com/hashicorp/go-immutable-radix v1.3.1
-	github.com/hashicorp/golang-lru v1.0.2
 	github.com/hectane/go-acl v0.0.0-20230122075934-ca0b05cb1adb
 	github.com/jedisct1/dlog v0.0.0-20230811132706-443b333ff1b3
 	github.com/jedisct1/go-clocksmith v0.0.0-20230211133011-392c1afea73e
@@ -19,6 +18,7 @@ require (
 	github.com/k-sone/critbitgo v1.4.0
 	github.com/kardianos/service v1.2.2
 	github.com/miekg/dns v1.1.58
+	github.com/opencoff/go-sieve v0.2.1
 	github.com/powerman/check v1.7.0
 	github.com/quic-go/quic-go v0.41.0
 	golang.org/x/crypto v0.18.0
@@ -33,6 +33,7 @@ require (
 	github.com/golang/protobuf v1.5.3 // indirect
 	github.com/google/pprof v0.0.0-20210407192527-94a9f03dee38 // indirect
 	github.com/hashicorp/go-syslog v1.0.0 // indirect
+	github.com/hashicorp/golang-lru v0.5.0 // indirect
 	github.com/onsi/ginkgo/v2 v2.9.5 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect

go.sum

@@ -32,9 +32,8 @@ github.com/hashicorp/go-syslog v1.0.0 h1:KaodqZuhUoZereWVIYmpUgZysurB1kBLX2j0MwM
 github.com/hashicorp/go-syslog v1.0.0/go.mod h1:qPfqrKkXGihmCqbJM2mZgkZGvKG1dFdvsLplgctolz4=
 github.com/hashicorp/go-uuid v1.0.0 h1:RS8zrF7PhGwyNPOtxSClXXj9HA8feRnJzgnI1RJCSnM=
 github.com/hashicorp/go-uuid v1.0.0/go.mod h1:6SBZvOh/SIDV7/2o3Jml5SYk/TvGqwFJ/bN7x4byOro=
+github.com/hashicorp/golang-lru v0.5.0 h1:CL2msUPvZTLb5O648aiLNJw3hnBxN2+1Jq8rCOH9wdo=
 github.com/hashicorp/golang-lru v0.5.0/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
-github.com/hashicorp/golang-lru v1.0.2 h1:dV3g9Z/unq5DpblPpw+Oqcv4dU/1omnb4Ok8iPY6p1c=
-github.com/hashicorp/golang-lru v1.0.2/go.mod h1:iADmTwqILo4mZ8BN3D2Q6+9jd8WM5uGBxy+E8yxSoD4=
 github.com/hectane/go-acl v0.0.0-20230122075934-ca0b05cb1adb h1:PGufWXXDq9yaev6xX1YQauaO1MV90e6Mpoq1I7Lz/VM=
 github.com/hectane/go-acl v0.0.0-20230122075934-ca0b05cb1adb/go.mod h1:QiyDdbZLaJ/mZP4Zwc9g2QsfaEA4o7XvvgZegSci5/E=
 github.com/ianlancetaylor/demangle v0.0.0-20200824232613-28f6c0f3b639/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
@@ -62,6 +61,8 @@ github.com/onsi/ginkgo/v2 v2.9.5 h1:+6Hr4uxzP4XIUyAkg61dWBw8lb/gc4/X5luuxN/EC+Q=
 github.com/onsi/ginkgo/v2 v2.9.5/go.mod h1:tvAoo1QUJwNEU2ITftXTpR7R1RbCzoZUOs3RonqW57k=
 github.com/onsi/gomega v1.27.6 h1:ENqfyGeS5AX/rlXDd/ETokDz93u0YufY1Pgxuy/PvWE=
 github.com/onsi/gomega v1.27.6/go.mod h1:PIQNjfQwkP3aQAH7lf7j87O/5FiNr+ZR8+ipb+qQlhg=
+github.com/opencoff/go-sieve v0.2.1 h1:5Pv6rd3zRquNmXcYHFndjVoolTgcv0ua2XTdMQ+gw0M=
+github.com/opencoff/go-sieve v0.2.1/go.mod h1:CndxLpW4R8fDq04XfBSCOZ+qWwDCcxjfUJbr0GPqWHY=
 github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=

vendor/github.com/hashicorp/golang-lru/.gitignore

@@ -1,23 +0,0 @@
-# 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

vendor/github.com/hashicorp/golang-lru/.golangci.yml

@@ -1,30 +0,0 @@
-linters:
-  enable:
-    - megacheck
-    - revive
-    - govet
-    - unconvert
-    - megacheck
-    - gas
-    - gocyclo
-    - dupl
-    - misspell
-    - unparam
-    - unused
-    - typecheck
-    - ineffassign
-    - stylecheck
-    - exportloopref
-    - gocritic
-    - nakedret
-    - gosimple
-    - prealloc
-  fast: false
-  disable-all: true
-
-issues:
-  exclude-rules:
-    - path: _test\.go
-      linters:
-        - dupl
-  exclude-use-default: false

vendor/github.com/hashicorp/golang-lru/2q.go

@@ -1,222 +0,0 @@
-package lru
-
-import (
-	"fmt"
-	"sync"
-
-	"github.com/hashicorp/golang-lru/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 struct {
-	size       int
-	recentSize int
-
-	recent      simplelru.LRUCache
-	frequent    simplelru.LRUCache
-	recentEvict simplelru.LRUCache
-	lock        sync.RWMutex
-}
-
-// New2Q creates a new TwoQueueCache using the default
-// values for the parameters.
-func New2Q(size int) (*TwoQueueCache, error) {
-	return New2QParams(size, Default2QRecentRatio, Default2QGhostEntries)
-}
-
-// New2QParams creates a new TwoQueueCache using the provided
-// parameter values.
-func New2QParams(size int, recentRatio, ghostRatio float64) (*TwoQueueCache, error) {
-	if size <= 0 {
-		return nil, fmt.Errorf("invalid size")
-	}
-	if recentRatio < 0.0 || recentRatio > 1.0 {
-		return nil, fmt.Errorf("invalid recent ratio")
-	}
-	if ghostRatio < 0.0 || ghostRatio > 1.0 {
-		return nil, fmt.Errorf("invalid ghost ratio")
-	}
-
-	// Determine the sub-sizes
-	recentSize := int(float64(size) * recentRatio)
-	evictSize := int(float64(size) * ghostRatio)
-
-	// Allocate the LRUs
-	recent, err := simplelru.NewLRU(size, nil)
-	if err != nil {
-		return nil, err
-	}
-	frequent, err := simplelru.NewLRU(size, nil)
-	if err != nil {
-		return nil, err
-	}
-	recentEvict, err := simplelru.NewLRU(evictSize, nil)
-	if err != nil {
-		return nil, err
-	}
-
-	// Initialize the cache
-	c := &TwoQueueCache{
-		size:        size,
-		recentSize:  recentSize,
-		recent:      recent,
-		frequent:    frequent,
-		recentEvict: recentEvict,
-	}
-	return c, nil
-}
-
-// Get looks up a key's value from the cache.
-func (c *TwoQueueCache) Get(key interface{}) (value interface{}, 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 nil, false
-}
-
-// Add adds a value to the cache.
-func (c *TwoQueueCache) Add(key, value interface{}) {
-	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) 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, nil)
-		return
-	}
-
-	// Remove from the frequent list otherwise
-	c.frequent.RemoveOldest()
-}
-
-// Len returns the number of items in the cache.
-func (c *TwoQueueCache) Len() int {
-	c.lock.RLock()
-	defer c.lock.RUnlock()
-	return c.recent.Len() + c.frequent.Len()
-}
-
-// Keys returns a slice of the keys in the cache.
-// The frequently used keys are first in the returned slice.
-func (c *TwoQueueCache) Keys() []interface{} {
-	c.lock.RLock()
-	defer c.lock.RUnlock()
-	k1 := c.frequent.Keys()
-	k2 := c.recent.Keys()
-	return append(k1, k2...)
-}
-
-// Remove removes the provided key from the cache.
-func (c *TwoQueueCache) Remove(key interface{}) {
-	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) 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) Contains(key interface{}) 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) Peek(key interface{}) (value interface{}, 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)
-}

vendor/github.com/hashicorp/golang-lru/LICENSE

@@ -1,5 +1,3 @@
-Copyright (c) 2014 HashiCorp, Inc.
-
 Mozilla Public License, version 2.0
 
 1. Definitions

vendor/github.com/hashicorp/golang-lru/README.md

@@ -1,7 +0,0 @@
-golang-lru
-==========
-
-Please upgrade to github.com/hashicorp/golang-lru/v2 for all new code as v1 will
-not be updated anymore. The v2 version supports generics and is faster; old code
-can specify a specific tag, e.g. github.com/hashicorp/golang-lru/v1.0.2 for
-backwards compatibility.

vendor/github.com/hashicorp/golang-lru/arc.go

@@ -1,256 +0,0 @@
-package lru
-
-import (
-	"sync"
-
-	"github.com/hashicorp/golang-lru/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 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 // T1 is the LRU for recently accessed items
-	b1 simplelru.LRUCache // B1 is the LRU for evictions from t1
-
-	t2 simplelru.LRUCache // T2 is the LRU for frequently accessed items
-	b2 simplelru.LRUCache // B2 is the LRU for evictions from t2
-
-	lock sync.RWMutex
-}
-
-// NewARC creates an ARC of the given size
-func NewARC(size int) (*ARCCache, error) {
-	// Create the sub LRUs
-	b1, err := simplelru.NewLRU(size, nil)
-	if err != nil {
-		return nil, err
-	}
-	b2, err := simplelru.NewLRU(size, nil)
-	if err != nil {
-		return nil, err
-	}
-	t1, err := simplelru.NewLRU(size, nil)
-	if err != nil {
-		return nil, err
-	}
-	t2, err := simplelru.NewLRU(size, nil)
-	if err != nil {
-		return nil, err
-	}
-
-	// Initialize the ARC
-	c := &ARCCache{
-		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) Get(key interface{}) (value interface{}, 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 nil, false
-}
-
-// Add adds a value to the cache.
-func (c *ARCCache) Add(key, value interface{}) {
-	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) 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, nil)
-		}
-	} else {
-		k, _, ok := c.t2.RemoveOldest()
-		if ok {
-			c.b2.Add(k, nil)
-		}
-	}
-}
-
-// Len returns the number of cached entries
-func (c *ARCCache) 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) Keys() []interface{} {
-	c.lock.RLock()
-	defer c.lock.RUnlock()
-	k1 := c.t1.Keys()
-	k2 := c.t2.Keys()
-	return append(k1, k2...)
-}
-
-// Remove is used to purge a key from the cache
-func (c *ARCCache) Remove(key interface{}) {
-	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) 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) Contains(key interface{}) 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) Peek(key interface{}) (value interface{}, 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)
-}

vendor/github.com/hashicorp/golang-lru/doc.go

@@ -1,21 +0,0 @@
-// 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.
-//
-// All caches in this package take locks while operating, and are therefore
-// thread-safe for consumers.
-package lru

vendor/github.com/hashicorp/golang-lru/lru.go

@@ -1,231 +0,0 @@
-package lru
-
-import (
-	"sync"
-
-	"github.com/hashicorp/golang-lru/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 struct {
-	lru                      *simplelru.LRU
-	evictedKeys, evictedVals []interface{}
-	onEvictedCB              func(k, v interface{})
-	lock                     sync.RWMutex
-}
-
-// New creates an LRU of the given size.
-func New(size int) (*Cache, error) {
-	return NewWithEvict(size, nil)
-}
-
-// NewWithEvict constructs a fixed size cache with the given eviction
-// callback.
-func NewWithEvict(size int, onEvicted func(key, value interface{})) (c *Cache, err error) {
-	// create a cache with default settings
-	c = &Cache{
-		onEvictedCB: onEvicted,
-	}
-	if onEvicted != nil {
-		c.initEvictBuffers()
-		onEvicted = c.onEvicted
-	}
-	c.lru, err = simplelru.NewLRU(size, onEvicted)
-	return
-}
-
-func (c *Cache) initEvictBuffers() {
-	c.evictedKeys = make([]interface{}, 0, DefaultEvictedBufferSize)
-	c.evictedVals = make([]interface{}, 0, DefaultEvictedBufferSize)
-}
-
-// onEvicted save evicted key/val and sent in externally registered callback
-// outside of critical section
-func (c *Cache) onEvicted(k, v interface{}) {
-	c.evictedKeys = append(c.evictedKeys, k)
-	c.evictedVals = append(c.evictedVals, v)
-}
-
-// Purge is used to completely clear the cache.
-func (c *Cache) Purge() {
-	var ks, vs []interface{}
-	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) Add(key, value interface{}) (evicted bool) {
-	var k, v interface{}
-	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) Get(key interface{}) (value interface{}, 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) Contains(key interface{}) 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) Peek(key interface{}) (value interface{}, 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) ContainsOrAdd(key, value interface{}) (ok, evicted bool) {
-	var k, v interface{}
-	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) PeekOrAdd(key, value interface{}) (previous interface{}, ok, evicted bool) {
-	var k, v interface{}
-	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 nil, false, evicted
-}
-
-// Remove removes the provided key from the cache.
-func (c *Cache) Remove(key interface{}) (present bool) {
-	var k, v interface{}
-	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) Resize(size int) (evicted int) {
-	var ks, vs []interface{}
-	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) RemoveOldest() (key, value interface{}, ok bool) {
-	var k, v interface{}
-	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) GetOldest() (key, value interface{}, 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) Keys() []interface{} {
-	c.lock.RLock()
-	keys := c.lru.Keys()
-	c.lock.RUnlock()
-	return keys
-}
-
-// Len returns the number of items in the cache.
-func (c *Cache) Len() int {
-	c.lock.RLock()
-	length := c.lru.Len()
-	c.lock.RUnlock()
-	return length
-}

vendor/github.com/hashicorp/golang-lru/simplelru/lru.go

@@ -25,7 +25,7 @@ type entry struct {
 // NewLRU constructs an LRU of the given size
 func NewLRU(size int, onEvict EvictCallback) (*LRU, error) {
 	if size <= 0 {
-		return nil, errors.New("must provide a positive size")
+		return nil, errors.New("Must provide a positive size")
 	}
 	c := &LRU{
 		size:      size,
@@ -73,9 +73,6 @@ func (c *LRU) Add(key, value interface{}) (evicted bool) {
 func (c *LRU) Get(key interface{}) (value interface{}, ok bool) {
 	if ent, ok := c.items[key]; ok {
 		c.evictList.MoveToFront(ent)
-		if ent.Value.(*entry) == nil {
-			return nil, false
-		}
 		return ent.Value.(*entry).value, true
 	}
 	return
@@ -109,7 +106,7 @@ func (c *LRU) Remove(key interface{}) (present bool) {
 }
 
 // RemoveOldest removes the oldest item from the cache.
-func (c *LRU) RemoveOldest() (key, value interface{}, ok bool) {
+func (c *LRU) RemoveOldest() (key interface{}, value interface{}, ok bool) {
 	ent := c.evictList.Back()
 	if ent != nil {
 		c.removeElement(ent)
@@ -120,7 +117,7 @@ func (c *LRU) RemoveOldest() (key, value interface{}, ok bool) {
 }
 
 // GetOldest returns the oldest entry
-func (c *LRU) GetOldest() (key, value interface{}, ok bool) {
+func (c *LRU) GetOldest() (key interface{}, value interface{}, ok bool) {
 	ent := c.evictList.Back()
 	if ent != nil {
 		kv := ent.Value.(*entry)
@@ -145,19 +142,6 @@ func (c *LRU) Len() int {
 	return c.evictList.Len()
 }
 
-// Resize changes the cache size.
-func (c *LRU) 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) removeOldest() {
 	ent := c.evictList.Back()

vendor/github.com/hashicorp/golang-lru/simplelru/lru_interface.go

@@ -1,4 +1,3 @@
-// Package simplelru provides simple LRU implementation based on build-in container/list.
 package simplelru
 
 // LRUCache is the interface for simple LRU cache.
@@ -11,7 +10,7 @@ type LRUCache interface {
 	// updates the "recently used"-ness of the key. #value, isFound
 	Get(key interface{}) (value interface{}, ok bool)
 
-	// Checks if a key exists in cache without updating the recent-ness.
+	// Check if a key exsists in cache without updating the recent-ness.
 	Contains(key interface{}) (ok bool)
 
 	// Returns key's value without updating the "recently used"-ness of the key.
@@ -32,9 +31,6 @@ type LRUCache interface {
 	// Returns the number of items in the cache.
 	Len() int
 
-	// Clears all cache entries.
+	// Clear all cache entries
 	Purge()
-
-	// Resizes cache, returning number evicted
-	Resize(int) int
 }

vendor/github.com/hashicorp/golang-lru/testing.go

@@ -1,16 +0,0 @@
-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()
-}

vendor/github.com/opencoff/go-sieve/.gitignore

@@ -0,0 +1,47 @@
+# 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
+*.prof
+
+bin/*
+.*.sw?
+.idea
+logs/*
+
+# gg ignores
+vendor/src/*
+vendor/pkg/*
+servers.iml
+*.DS_Store
+
+# vagrant ignores
+tools/vagrant/.vagrant
+tools/vagrant/adsrv-conf/.frontend
+tools/vagrant/adsrv-conf/.bidder
+tools/vagrant/adsrv-conf/.transcoder
+tools/vagrant/redis-cluster-conf/7777/nodes.conf
+tools/vagrant/redis-cluster-conf/7778/nodes.conf
+tools/vagrant/redis-cluster-conf/7779/nodes.conf
+*.aof
+*.rdb
+*.deb

vendor/github.com/opencoff/go-sieve/LICENSE

@@ -0,0 +1,24 @@
+BSD 2-Clause License
+
+Copyright (c) 2024, Sudhi Herle
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+
+2. 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.
+
+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 HOLDER 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.

vendor/github.com/opencoff/go-sieve/README.md

@@ -0,0 +1,9 @@
+# go-sieve - SIEVE is simpler than LRU
+
+## What is it?
+`go-sieve` is golang implementation of the [SIEVE](https://yazhuozhang.com/assets/pdf/nsdi24-sieve.pdf)
+cache eviction algorithm.
+
+This implementation closely follows the paper's pseudo-code - but
+uses golang generics to provide an ergonomic interface.
+

vendor/github.com/opencoff/go-sieve/sieve.go

@@ -0,0 +1,334 @@
+// sieve.go - SIEVE - a simple and efficient cache
+//
+// (c) 2024 Sudhi Herle <sudhi@herle.net>
+//
+// Copyright 2024- Sudhi Herle <sw-at-herle-dot-net>
+// License: BSD-2-Clause
+//
+// If you need a commercial license for this work, please contact
+// the author.
+//
+// This software does not come with any express or implied
+// warranty; it is provided "as is". No claim  is made to its
+// suitability for any purpose.
+
+// This is golang implementation of the SIEVE cache eviction algorithm
+// The original paper is:
+//	https://yazhuozhang.com/assets/pdf/nsdi24-sieve.pdf
+//
+// This implementation closely follows the paper - but uses golang generics
+// for an ergonomic interface.
+
+// Package sieve implements the SIEVE cache eviction algorithm.
+// SIEVE stands in contrast to other eviction algorithms like LRU, 2Q, ARC
+// with its simplicity. The original paper is in:
+// https://yazhuozhang.com/assets/pdf/nsdi24-sieve.pdf
+//
+// SIEVE is built on a FIFO queue - with an extra pointer (called "hand") in
+// the paper. This "hand" plays a crucial role in determining who to evict
+// next.
+package sieve
+
+import (
+	"fmt"
+	"strings"
+	"sync"
+	"sync/atomic"
+)
+
+// node contains the <key, val> tuple as a node in a linked list.
+type node[K comparable, V any] struct {
+	sync.Mutex
+	key     K
+	val     V
+	visited atomic.Bool
+	next    *node[K, V]
+	prev    *node[K, V]
+}
+
+// Sieve represents a cache mapping the key of type 'K' with
+// a value of type 'V'. The type 'K' must implement the
+// comparable trait. An instance of Sieve has a fixed max capacity;
+// new additions to the cache beyond the capacity will cause cache
+// eviction of other entries - as determined by the SIEVE algorithm.
+type Sieve[K comparable, V any] struct {
+	mu       sync.Mutex
+	cache    *syncMap[K, *node[K, V]]
+	head     *node[K, V]
+	tail     *node[K, V]
+	hand     *node[K, V]
+	size     int
+	capacity int
+
+	pool *syncPool[node[K, V]]
+}
+
+// New creates a new cache of size 'capacity' mapping key 'K' to value 'V'
+func New[K comparable, V any](capacity int) *Sieve[K, V] {
+	s := &Sieve[K, V]{
+		cache:    newSyncMap[K, *node[K, V]](),
+		capacity: capacity,
+		pool:     newSyncPool[node[K, V]](),
+	}
+	return s
+}
+
+// Get fetches the value for a given key in the cache.
+// It returns true if the key is in the cache, false otherwise.
+// The zero value for 'V' is returned when key is not in the cache.
+func (s *Sieve[K, V]) Get(key K) (V, bool) {
+
+	if v, ok := s.cache.Get(key); ok {
+		v.visited.Store(true)
+		return v.val, true
+	}
+
+	var x V
+	return x, false
+}
+
+// Add adds a new element to the cache or overwrite one if it exists
+// Return true if we replaced, false otherwise
+func (s *Sieve[K, V]) Add(key K, val V) bool {
+
+	if v, ok := s.cache.Get(key); ok {
+		v.visited.Store(true)
+		v.Lock()
+		v.val = val
+		v.Unlock()
+		return true
+	}
+
+	s.mu.Lock()
+	s.add(key, val)
+	s.mu.Unlock()
+	return false
+}
+
+// Probe adds <key, val> if not present in the cache.
+// Returns:
+//
+//	<cached-val, true> when key is present in the cache
+//	<val, false> when key is not present in the cache
+func (s *Sieve[K, V]) Probe(key K, val V) (V, bool) {
+
+	if v, ok := s.cache.Get(key); ok {
+		v.visited.Store(true)
+		return v.val, true
+	}
+
+	s.mu.Lock()
+	s.add(key, val)
+	s.mu.Unlock()
+	return val, false
+}
+
+// Delete deletes the named key from the cache
+// It returns true if the item was in the cache and false otherwise
+func (s *Sieve[K, V]) Delete(key K) bool {
+
+	if v, ok := s.cache.Del(key); ok {
+		s.mu.Lock()
+		s.remove(v)
+		s.mu.Unlock()
+		return true
+	}
+
+	return false
+}
+
+// Purge resets the cache
+func (s *Sieve[K, V]) Purge() {
+	s.mu.Lock()
+	s.cache = newSyncMap[K, *node[K, V]]()
+	s.head = nil
+	s.tail = nil
+	s.mu.Unlock()
+}
+
+// Len returns the current cache utilization
+func (s *Sieve[K, V]) Len() int {
+	return s.size
+}
+
+// Cap returns the max cache capacity
+func (s *Sieve[K, V]) Cap() int {
+	return s.capacity
+}
+
+// String returns a string description of the sieve cache
+func (s *Sieve[K, V]) String() string {
+	s.mu.Lock()
+	m := s.desc()
+	s.mu.Unlock()
+	return m
+}
+
+// Dump dumps all the cache contents as a newline delimited
+// string.
+func (s *Sieve[K, V]) Dump() string {
+	var b strings.Builder
+
+	s.mu.Lock()
+	b.WriteString(s.desc())
+	b.WriteRune('\n')
+	for n := s.head; n != nil; n = n.next {
+		h := "  "
+		if n == s.hand {
+			h = ">>"
+		}
+		b.WriteString(fmt.Sprintf("%svisited=%v, key=%v, val=%v\n", h, n.visited.Load(), n.key, n.val))
+	}
+	s.mu.Unlock()
+	return b.String()
+}
+
+// -- internal methods --
+
+// add a new tuple to the cache and evict as necessary
+// caller must hold lock.
+func (s *Sieve[K, V]) add(key K, val V) {
+	// cache miss; we evict and fnd a new node
+	if s.size == s.capacity {
+		s.evict()
+	}
+
+	n := s.newNode(key, val)
+
+	// Eviction is guaranteed to remove one node; so this should never happen.
+	if n == nil {
+		msg := fmt.Sprintf("%T: add <%v>: objpool empty after eviction", s, key)
+		panic(msg)
+	}
+
+	s.cache.Put(key, n)
+
+	// insert at the head of the list
+	n.next = s.head
+	n.prev = nil
+	if s.head != nil {
+		s.head.prev = n
+	}
+	s.head = n
+	if s.tail == nil {
+		s.tail = n
+	}
+
+	s.size += 1
+}
+
+// evict an item from the cache.
+// NB: Caller must hold the lock
+func (s *Sieve[K, V]) evict() {
+	hand := s.hand
+	if hand == nil {
+		hand = s.tail
+	}
+
+	for hand != nil {
+		if !hand.visited.Load() {
+			s.cache.Del(hand.key)
+			s.remove(hand)
+			s.hand = hand.prev
+			return
+		}
+		hand.visited.Store(false)
+		hand = hand.prev
+		// wrap around and start again
+		if hand == nil {
+			hand = s.tail
+		}
+	}
+	s.hand = hand
+}
+
+func (s *Sieve[K, V]) remove(n *node[K, V]) {
+	s.size -= 1
+
+	// remove node from list
+	if n.prev != nil {
+		n.prev.next = n.next
+	} else {
+		s.head = n.next
+	}
+	if n.next != nil {
+		n.next.prev = n.prev
+	} else {
+		s.tail = n.prev
+	}
+
+	s.pool.Put(n)
+}
+
+func (s *Sieve[K, V]) newNode(key K, val V) *node[K, V] {
+	n := s.pool.Get()
+	n.key, n.val = key, val
+	n.next, n.prev = nil, nil
+	n.visited.Store(false)
+
+	return n
+}
+
+// desc describes the properties of the sieve
+func (s *Sieve[K, V]) desc() string {
+	m := fmt.Sprintf("cache<%T>: size %d, cap %d, head=%p, tail=%p, hand=%p",
+		s, s.size, s.capacity, s.head, s.tail, s.hand)
+	return m
+}
+
+// Generic sync.Pool
+type syncPool[T any] struct {
+	pool sync.Pool
+}
+
+func newSyncPool[T any]() *syncPool[T] {
+	p := &syncPool[T]{
+		pool: sync.Pool{
+			New: func() any { return new(T) },
+		},
+	}
+	return p
+}
+
+func (s *syncPool[T]) Get() *T {
+	p := s.pool.Get()
+	return p.(*T)
+}
+
+func (s *syncPool[T]) Put(n *T) {
+	s.pool.Put(n)
+}
+
+// generic sync.Map
+type syncMap[K comparable, V any] struct {
+	m sync.Map
+}
+
+func newSyncMap[K comparable, V any]() *syncMap[K, V] {
+	m := syncMap[K, V]{}
+	return &m
+}
+
+func (m *syncMap[K, V]) Get(key K) (V, bool) {
+	v, ok := m.m.Load(key)
+	if ok {
+		return v.(V), true
+	}
+
+	var z V
+	return z, false
+}
+
+func (m *syncMap[K, V]) Put(key K, val V) {
+	m.m.Store(key, val)
+}
+
+func (m *syncMap[K, V]) Del(key K) (V, bool) {
+	x, ok := m.m.LoadAndDelete(key)
+	if ok {
+		return x.(V), true
+	}
+
+	var z V
+	return z, false
+}

vendor/modules.txt

@@ -34,9 +34,8 @@ github.com/hashicorp/go-immutable-radix
 # github.com/hashicorp/go-syslog v1.0.0
 ## explicit
 github.com/hashicorp/go-syslog
-# github.com/hashicorp/golang-lru v1.0.2
+# github.com/hashicorp/golang-lru v0.5.0
-## explicit; go 1.12
+## explicit
-github.com/hashicorp/golang-lru
 github.com/hashicorp/golang-lru/simplelru
 # github.com/hectane/go-acl v0.0.0-20230122075934-ca0b05cb1adb
 ## explicit; go 1.12
@@ -87,6 +86,9 @@ github.com/onsi/ginkgo/v2/internal/interrupt_handler
 github.com/onsi/ginkgo/v2/internal/parallel_support
 github.com/onsi/ginkgo/v2/reporters
 github.com/onsi/ginkgo/v2/types
+# github.com/opencoff/go-sieve v0.2.1
+## explicit; go 1.21.1
+github.com/opencoff/go-sieve
 # github.com/pkg/errors v0.9.1
 ## explicit
 github.com/pkg/errors