refactor: Refactor pool to use upstream hashicorp/golang-lru package

Author: bodgit

go.mod

@@ -23,3 +23,5 @@ require (
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
+
+replace github.com/hashicorp/golang-lru/v2 => github.com/bodgit/golang-lru/v2 v2.0.0-20240402231653-73e2fffc225d

go.sum

@@ -19,6 +19,8 @@ github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
 github.com/andybalholm/brotli v1.1.0 h1:eLKJA0d02Lf0mVpIDgYnqXcUn0GqVmEFny3VuID1U3M=
 github.com/andybalholm/brotli v1.1.0/go.mod h1:sms7XGricyQI9K10gOSf56VKKWS4oLer58Q+mhRPtnY=
+github.com/bodgit/golang-lru/v2 v2.0.0-20240402231653-73e2fffc225d h1:+VY4VHDvXKqMaaRcl7MUCs1YCIz7D4dC642ZClCGmXo=
+github.com/bodgit/golang-lru/v2 v2.0.0-20240402231653-73e2fffc225d/go.mod h1:QeFd9opnmA6QUJc5vARoKUSoFhyfM2/ZepoAG6RGpeM=
 github.com/bodgit/plumbing v1.3.0 h1:pf9Itz1JOQgn7vEOE7v7nlEfBykYqvUYioC61TwWCFU=
 github.com/bodgit/plumbing v1.3.0/go.mod h1:JOTb4XiRu5xfnmdnDJo6GmSbSbtSyufrsyZFByMtKEs=
 github.com/bodgit/windows v1.0.1 h1:tF7K6KOluPYygXa3Z2594zxlkbKPAOvqr97etrGNIz4=
@@ -66,8 +68,6 @@ github.com/hashicorp/go-multierror v1.1.1 h1:H5DkEtf6CXdFp0N0Em5UCwQpXMWke8IA0+l
 github.com/hashicorp/go-multierror v1.1.1/go.mod h1:iw975J/qwKPdAO1clOe2L8331t/9/fmwbPZ6JB6eMoM=
 github.com/hashicorp/golang-lru v0.5.0/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
 github.com/hashicorp/golang-lru v0.5.1/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
-github.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=
 github.com/ianlancetaylor/demangle v0.0.0-20181102032728-5e5cf60278f6/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
 github.com/jstemmer/go-junit-report v0.0.0-20190106144839-af01ea7f8024/go.mod h1:6v2b51hI/fHJwM22ozAgKL4VKDeJcHhJFhtBdhmNjmU=
 github.com/jstemmer/go-junit-report v0.9.1/go.mod h1:Brl9GWCQeLvo8nXZwPNNblvFj/XSXhF0NWZEnDohbsk=

internal/pool/pool.go

@@ -1,12 +1,12 @@
 package pool
 
 import (
-	"container/list"
 	"runtime"
 	"sort"
 	"sync"
 
 	"github.com/bodgit/sevenzip/internal/util"
+	lru "github.com/hashicorp/golang-lru/v2"
 )
 
 // Pooler is the interface implemented by a pool.
@@ -34,48 +34,54 @@ func (noopPool) Put(_ int64, rc util.SizeReadSeekCloser) (bool, error) {
 }
 
 type pool struct {
-	mutex     sync.Mutex
-	size      int
-	evictList *list.List
-	items     map[int64]*list.Element
-}
-
-type entry struct {
-	key   int64
-	value util.SizeReadSeekCloser
+	mutex sync.Mutex
+	errs  chan error
+	cache *lru.Cache[int64, util.SizeReadSeekCloser]
 }
 
 // NewPool returns a Pooler that uses a LRU strategy to maintain a fixed pool
 // of util.SizeReadSeekCloser's keyed by their stream offset.
 func NewPool() (Pooler, error) {
+	errs := make(chan error)
+
+	cache, err := lru.NewWithEvict[int64, util.SizeReadSeekCloser](
+		runtime.NumCPU(),
+		func(_ int64, value util.SizeReadSeekCloser) {
+			if err := value.Close(); err != nil {
+				errs <- err
+			}
+		})
+	if err != nil {
+		return nil, err
+	}
+
 	return &pool{
-		size:      runtime.NumCPU(),
-		evictList: list.New(),
-		items:     make(map[int64]*list.Element),
+		errs:  errs,
+		cache: cache,
 	}, nil
 }
 
 func (p *pool) Get(offset int64) (util.SizeReadSeekCloser, bool) {
 	p.mutex.Lock()
 	defer p.mutex.Unlock()
 
-	if ent, ok := p.items[offset]; ok {
-		_ = p.removeElement(ent, false)
+	if reader, ok := p.cache.Get(offset); ok {
+		_ = p.cache.RemoveWithoutEvict(offset)
 
-		return ent.Value.(*entry).value, true //nolint:forcetypeassert
+		return reader, true
 	}
 
 	// Sort keys in descending order
-	keys := p.keys()
+	keys := p.cache.Keys()
 	sort.Slice(keys, func(i, j int) bool { return keys[i] > keys[j] })
 
 	for _, k := range keys {
 		// First key less than offset is the closest
 		if k < offset {
-			ent := p.items[k]
-			_ = p.removeElement(ent, false)
+			reader, _ := p.cache.Get(k)
+			_ = p.cache.RemoveWithoutEvict(k)
 
-			return ent.Value.(*entry).value, true //nolint:forcetypeassert
+			return reader, true
 		}
 	}
 
@@ -86,52 +92,13 @@ func (p *pool) Put(offset int64, rc util.SizeReadSeekCloser) (bool, error) {
 	p.mutex.Lock()
 	defer p.mutex.Unlock()
 
-	if _, ok := p.items[offset]; ok {
-		return false, nil
-	}
-
-	ent := &entry{offset, rc}
-	entry := p.evictList.PushFront(ent)
-	p.items[offset] = entry
-
-	var err error
-
-	evict := p.evictList.Len() > p.size
-	if evict {
-		err = p.removeOldest()
-	}
-
-	return evict, err
-}
-
-func (p *pool) keys() []int64 {
-	keys := make([]int64, len(p.items))
-	i := 0
-
-	for ent := p.evictList.Back(); ent != nil; ent = ent.Prev() {
-		keys[i] = ent.Value.(*entry).key //nolint:forcetypeassert
-		i++
-	}
-
-	return keys
-}
-
-func (p *pool) removeOldest() error {
-	if ent := p.evictList.Back(); ent != nil {
-		return p.removeElement(ent, true)
-	}
-
-	return nil
-}
-
-func (p *pool) removeElement(e *list.Element, cb bool) error {
-	p.evictList.Remove(e)
-	kv := e.Value.(*entry) //nolint:forcetypeassert
-	delete(p.items, kv.key)
+	_, ok := p.cache.ContainsOrAdd(offset, rc)
 
-	if cb {
-		return kv.value.Close()
+	select {
+	case err := <-p.errs:
+		return ok, err
+	default:
 	}
 
-	return nil
+	return ok, nil
 }