From 06b780f5cc7f1d41e2e0c708370da3e9e34e520c Mon Sep 17 00:00:00 2001
From: gVisor bot <gvisor-bot@google.com>
Date: Wed, 6 Apr 2022 01:07:08 +0800
Subject: [PATCH] Refactor: queue use generics

---
 adapter/adapter.go    | 12 ++++--------
 common/queue/queue.go | 31 ++++++++++++++++++-------------
 2 files changed, 22 insertions(+), 21 deletions(-)

diff --git a/adapter/adapter.go b/adapter/adapter.go
index dbb31bf0..1fd9bc11 100644
--- a/adapter/adapter.go
+++ b/adapter/adapter.go
@@ -21,7 +21,7 @@ var UnifiedDelay = atomic.NewBool(false)
 
 type Proxy struct {
 	C.ProxyAdapter
-	history *queue.Queue
+	history *queue.Queue[C.DelayHistory]
 	alive   *atomic.Bool
 }
 
@@ -67,7 +67,7 @@ func (p *Proxy) DelayHistory() []C.DelayHistory {
 	queue := p.history.Copy()
 	histories := []C.DelayHistory{}
 	for _, item := range queue {
-		histories = append(histories, item.(C.DelayHistory))
+		histories = append(histories, item)
 	}
 	return histories
 }
@@ -80,11 +80,7 @@ func (p *Proxy) LastDelay() (delay uint16) {
 		return max
 	}
 
-	last := p.history.Last()
-	if last == nil {
-		return max
-	}
-	history := last.(C.DelayHistory)
+	history := p.history.Last()
 	if history.Delay == 0 {
 		return max
 	}
@@ -178,7 +174,7 @@ func (p *Proxy) URLTest(ctx context.Context, url string) (t uint16, err error) {
 }
 
 func NewProxy(adapter C.ProxyAdapter) *Proxy {
-	return &Proxy{adapter, queue.New(10), atomic.NewBool(true)}
+	return &Proxy{adapter, queue.New[C.DelayHistory](10), atomic.NewBool(true)}
 }
 
 func urlToMetadata(rawURL string) (addr C.Metadata, err error) {
diff --git a/common/queue/queue.go b/common/queue/queue.go
index 60257f56..4755cb35 100644
--- a/common/queue/queue.go
+++ b/common/queue/queue.go
@@ -5,13 +5,13 @@ import (
 )
 
 // Queue is a simple concurrent safe queue
-type Queue struct {
-	items []any
+type Queue[T any] struct {
+	items []T
 	lock  sync.RWMutex
 }
 
 // Put add the item to the queue.
-func (q *Queue) Put(items ...any) {
+func (q *Queue[T]) Put(items ...T) {
 	if len(items) == 0 {
 		return
 	}
@@ -22,9 +22,9 @@ func (q *Queue) Put(items ...any) {
 }
 
 // Pop returns the head of items.
-func (q *Queue) Pop() any {
+func (q *Queue[T]) Pop() T {
 	if len(q.items) == 0 {
-		return nil
+		return GetZero[T]()
 	}
 
 	q.lock.Lock()
@@ -35,9 +35,9 @@ func (q *Queue) Pop() any {
 }
 
 // Last returns the last of item.
-func (q *Queue) Last() any {
+func (q *Queue[T]) Last() T {
 	if len(q.items) == 0 {
-		return nil
+		return GetZero[T]()
 	}
 
 	q.lock.RLock()
@@ -47,8 +47,8 @@ func (q *Queue) Last() any {
 }
 
 // Copy get the copy of queue.
-func (q *Queue) Copy() []any {
-	items := []any{}
+func (q *Queue[T]) Copy() []T {
+	items := []T{}
 	q.lock.RLock()
 	items = append(items, q.items...)
 	q.lock.RUnlock()
@@ -56,7 +56,7 @@ func (q *Queue) Copy() []any {
 }
 
 // Len returns the number of items in this queue.
-func (q *Queue) Len() int64 {
+func (q *Queue[T]) Len() int64 {
 	q.lock.Lock()
 	defer q.lock.Unlock()
 
@@ -64,8 +64,13 @@ func (q *Queue) Len() int64 {
 }
 
 // New is a constructor for a new concurrent safe queue.
-func New(hint int64) *Queue {
-	return &Queue{
-		items: make([]any, 0, hint),
+func New[T any](hint int64) *Queue[T] {
+	return &Queue[T]{
+		items: make([]T, 0, hint),
 	}
 }
+
+func GetZero[T any]() T {
+	var result T
+	return result
+}