common/prque: generic priority queue (#26290)

* common, core, eth, les, trie: make prque generic

* les/vflux/server: fixed issues in priorityPool

* common, core, eth, les, trie: make priority also generic in prque

* les/flowcontrol: add test case for priority accumulator overflow

* les/flowcontrol: avoid priority value overflow

* common/prque: use int priority in some tests

No need to convert to int64 when we can just change the type used by the
queue.

* common/prque: remove comment about int64 range

---------

Co-authored-by: Zsolt Felfoldi <zsfelfoldi@gmail.com>
Co-authored-by: Felix Lange <fjl@twurst.com>

common/prque/lazyqueue.go

@@ -21,6 +21,7 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/common/mclock"
+	"golang.org/x/exp/constraints"
 )
 
 // LazyQueue is a priority queue data structure where priorities can change over
@@ -32,31 +33,31 @@ import (
 //
 // If the upper estimate is exceeded then Update should be called for that item.
 // A global Refresh function should also be called periodically.
-type LazyQueue struct {
+type LazyQueue[P constraints.Ordered, V any] struct {
 	clock mclock.Clock
 	// Items are stored in one of two internal queues ordered by estimated max
 	// priority until the next and the next-after-next refresh. Update and Refresh
 	// always places items in queue[1].
-	queue                      [2]*sstack
+	queue                      [2]*sstack[P, V]
-	popQueue                   *sstack
+	popQueue                   *sstack[P, V]
 	period                     time.Duration
 	maxUntil                   mclock.AbsTime
 	indexOffset                int
-	setIndex                   SetIndexCallback
+	setIndex                   SetIndexCallback[V]
-	priority                   PriorityCallback
+	priority                   PriorityCallback[P, V]
-	maxPriority                MaxPriorityCallback
+	maxPriority                MaxPriorityCallback[P, V]
 	lastRefresh1, lastRefresh2 mclock.AbsTime
 }
 
 type (
-	PriorityCallback    func(data interface{}) int64                       // actual priority callback
+	PriorityCallback[P constraints.Ordered, V any]    func(data V) P                       // actual priority callback
-	MaxPriorityCallback func(data interface{}, until mclock.AbsTime) int64 // estimated maximum priority callback
+	MaxPriorityCallback[P constraints.Ordered, V any] func(data V, until mclock.AbsTime) P // estimated maximum priority callback
 )
 
 // NewLazyQueue creates a new lazy queue
-func NewLazyQueue(setIndex SetIndexCallback, priority PriorityCallback, maxPriority MaxPriorityCallback, clock mclock.Clock, refreshPeriod time.Duration) *LazyQueue {
+func NewLazyQueue[P constraints.Ordered, V any](setIndex SetIndexCallback[V], priority PriorityCallback[P, V], maxPriority MaxPriorityCallback[P, V], clock mclock.Clock, refreshPeriod time.Duration) *LazyQueue[P, V] {
-	q := &LazyQueue{
+	q := &LazyQueue[P, V]{
-		popQueue:     newSstack(nil, false),
+		popQueue:     newSstack[P, V](nil),
 		setIndex:     setIndex,
 		priority:     priority,
 		maxPriority:  maxPriority,
@@ -71,13 +72,13 @@ func NewLazyQueue(setIndex SetIndexCallback, priority PriorityCallback, maxPrior
 }
 
 // Reset clears the contents of the queue
-func (q *LazyQueue) Reset() {
+func (q *LazyQueue[P, V]) Reset() {
-	q.queue[0] = newSstack(q.setIndex0, false)
+	q.queue[0] = newSstack[P, V](q.setIndex0)
-	q.queue[1] = newSstack(q.setIndex1, false)
+	q.queue[1] = newSstack[P, V](q.setIndex1)
 }
 
 // Refresh performs queue re-evaluation if necessary
-func (q *LazyQueue) Refresh() {
+func (q *LazyQueue[P, V]) Refresh() {
 	now := q.clock.Now()
 	for time.Duration(now-q.lastRefresh2) >= q.period*2 {
 		q.refresh(now)
@@ -87,10 +88,10 @@ func (q *LazyQueue) Refresh() {
 }
 
 // refresh re-evaluates items in the older queue and swaps the two queues
-func (q *LazyQueue) refresh(now mclock.AbsTime) {
+func (q *LazyQueue[P, V]) refresh(now mclock.AbsTime) {
 	q.maxUntil = now.Add(q.period)
 	for q.queue[0].Len() != 0 {
-		q.Push(heap.Pop(q.queue[0]).(*item).value)
+		q.Push(heap.Pop(q.queue[0]).(*item[P, V]).value)
 	}
 	q.queue[0], q.queue[1] = q.queue[1], q.queue[0]
 	q.indexOffset = 1 - q.indexOffset
@@ -98,22 +99,22 @@ func (q *LazyQueue) refresh(now mclock.AbsTime) {
 }
 
 // Push adds an item to the queue
-func (q *LazyQueue) Push(data interface{}) {
+func (q *LazyQueue[P, V]) Push(data V) {
-	heap.Push(q.queue[1], &item{data, q.maxPriority(data, q.maxUntil)})
+	heap.Push(q.queue[1], &item[P, V]{data, q.maxPriority(data, q.maxUntil)})
 }
 
 // Update updates the upper priority estimate for the item with the given queue index
-func (q *LazyQueue) Update(index int) {
+func (q *LazyQueue[P, V]) Update(index int) {
 	q.Push(q.Remove(index))
 }
 
 // Pop removes and returns the item with the greatest actual priority
-func (q *LazyQueue) Pop() (interface{}, int64) {
+func (q *LazyQueue[P, V]) Pop() (V, P) {
 	var (
-		resData interface{}
+		resData V
-		resPri  int64
+		resPri  P
 	)
-	q.MultiPop(func(data interface{}, priority int64) bool {
+	q.MultiPop(func(data V, priority P) bool {
 		resData = data
 		resPri = priority
 		return false
@@ -123,7 +124,7 @@ func (q *LazyQueue) Pop() (interface{}, int64) {
 
 // peekIndex returns the index of the internal queue where the item with the
 // highest estimated priority is or -1 if both are empty
-func (q *LazyQueue) peekIndex() int {
+func (q *LazyQueue[P, V]) peekIndex() int {
 	if q.queue[0].Len() != 0 {
 		if q.queue[1].Len() != 0 && q.queue[1].blocks[0][0].priority > q.queue[0].blocks[0][0].priority {
 			return 1
@@ -139,17 +140,17 @@ func (q *LazyQueue) peekIndex() int {
 // MultiPop pops multiple items from the queue and is more efficient than calling
 // Pop multiple times. Popped items are passed to the callback. MultiPop returns
 // when the callback returns false or there are no more items to pop.
-func (q *LazyQueue) MultiPop(callback func(data interface{}, priority int64) bool) {
+func (q *LazyQueue[P, V]) MultiPop(callback func(data V, priority P) bool) {
 	nextIndex := q.peekIndex()
 	for nextIndex != -1 {
-		data := heap.Pop(q.queue[nextIndex]).(*item).value
+		data := heap.Pop(q.queue[nextIndex]).(*item[P, V]).value
-		heap.Push(q.popQueue, &item{data, q.priority(data)})
+		heap.Push(q.popQueue, &item[P, V]{data, q.priority(data)})
 		nextIndex = q.peekIndex()
 		for q.popQueue.Len() != 0 && (nextIndex == -1 || q.queue[nextIndex].blocks[0][0].priority < q.popQueue.blocks[0][0].priority) {
-			i := heap.Pop(q.popQueue).(*item)
+			i := heap.Pop(q.popQueue).(*item[P, V])
 			if !callback(i.value, i.priority) {
 				for q.popQueue.Len() != 0 {
-					q.Push(heap.Pop(q.popQueue).(*item).value)
+					q.Push(heap.Pop(q.popQueue).(*item[P, V]).value)
 				}
 				return
 			}
@@ -159,31 +160,28 @@ func (q *LazyQueue) MultiPop(callback func(data interface{}, priority int64) boo
 }
 
 // PopItem pops the item from the queue only, dropping the associated priority value.
-func (q *LazyQueue) PopItem() interface{} {
+func (q *LazyQueue[P, V]) PopItem() V {
 	i, _ := q.Pop()
 	return i
 }
 
 // Remove removes the item with the given index.
-func (q *LazyQueue) Remove(index int) interface{} {
+func (q *LazyQueue[P, V]) Remove(index int) V {
-	if index < 0 {
+	return heap.Remove(q.queue[index&1^q.indexOffset], index>>1).(*item[P, V]).value
-		return nil
-	}
-	return heap.Remove(q.queue[index&1^q.indexOffset], index>>1).(*item).value
 }
 
 // Empty checks whether the priority queue is empty.
-func (q *LazyQueue) Empty() bool {
+func (q *LazyQueue[P, V]) Empty() bool {
 	return q.queue[0].Len() == 0 && q.queue[1].Len() == 0
 }
 
 // Size returns the number of items in the priority queue.
-func (q *LazyQueue) Size() int {
+func (q *LazyQueue[P, V]) Size() int {
 	return q.queue[0].Len() + q.queue[1].Len()
 }
 
 // setIndex0 translates internal queue item index to the virtual index space of LazyQueue
-func (q *LazyQueue) setIndex0(data interface{}, index int) {
+func (q *LazyQueue[P, V]) setIndex0(data V, index int) {
 	if index == -1 {
 		q.setIndex(data, -1)
 	} else {
@@ -192,6 +190,6 @@ func (q *LazyQueue) setIndex0(data interface{}, index int) {
 }
 
 // setIndex1 translates internal queue item index to the virtual index space of LazyQueue
-func (q *LazyQueue) setIndex1(data interface{}, index int) {
+func (q *LazyQueue[P, V]) setIndex1(data V, index int) {
 	q.setIndex(data, index+index+1)
 }

common/prque/prque.go

@@ -19,65 +19,59 @@ package prque
 
 import (
 	"container/heap"
+
+	"golang.org/x/exp/constraints"
 )
 
 // Priority queue data structure.
-type Prque struct {
+type Prque[P constraints.Ordered, V any] struct {
-	cont *sstack
+	cont *sstack[P, V]
 }
 
 // New creates a new priority queue.
-func New(setIndex SetIndexCallback) *Prque {
+func New[P constraints.Ordered, V any](setIndex SetIndexCallback[V]) *Prque[P, V] {
-	return &Prque{newSstack(setIndex, false)}
+	return &Prque[P, V]{newSstack[P, V](setIndex)}
-}
-
-// NewWrapAround creates a new priority queue with wrap-around priority handling.
-func NewWrapAround(setIndex SetIndexCallback) *Prque {
-	return &Prque{newSstack(setIndex, true)}
 }
 
 // Pushes a value with a given priority into the queue, expanding if necessary.
-func (p *Prque) Push(data interface{}, priority int64) {
+func (p *Prque[P, V]) Push(data V, priority P) {
-	heap.Push(p.cont, &item{data, priority})
+	heap.Push(p.cont, &item[P, V]{data, priority})
 }
 
 // Peek returns the value with the greatest priority but does not pop it off.
-func (p *Prque) Peek() (interface{}, int64) {
+func (p *Prque[P, V]) Peek() (V, P) {
 	item := p.cont.blocks[0][0]
 	return item.value, item.priority
 }
 
 // Pops the value with the greatest priority off the stack and returns it.
 // Currently no shrinking is done.
-func (p *Prque) Pop() (interface{}, int64) {
+func (p *Prque[P, V]) Pop() (V, P) {
-	item := heap.Pop(p.cont).(*item)
+	item := heap.Pop(p.cont).(*item[P, V])
 	return item.value, item.priority
 }
 
 // Pops only the item from the queue, dropping the associated priority value.
-func (p *Prque) PopItem() interface{} {
+func (p *Prque[P, V]) PopItem() V {
-	return heap.Pop(p.cont).(*item).value
+	return heap.Pop(p.cont).(*item[P, V]).value
 }
 
 // Remove removes the element with the given index.
-func (p *Prque) Remove(i int) interface{} {
+func (p *Prque[P, V]) Remove(i int) V {
-	if i < 0 {
+	return heap.Remove(p.cont, i).(*item[P, V]).value
-		return nil
-	}
-	return heap.Remove(p.cont, i)
 }
 
 // Checks whether the priority queue is empty.
-func (p *Prque) Empty() bool {
+func (p *Prque[P, V]) Empty() bool {
 	return p.cont.Len() == 0
 }
 
 // Returns the number of element in the priority queue.
-func (p *Prque) Size() int {
+func (p *Prque[P, V]) Size() int {
 	return p.cont.Len()
 }
 
 // Clears the contents of the priority queue.
-func (p *Prque) Reset() {
+func (p *Prque[P, V]) Reset() {
-	*p = *New(p.cont.setIndex)
+	*p = *New[P, V](p.cont.setIndex)
 }

common/prque/prque_test.go

@@ -21,22 +21,24 @@ func TestPrque(t *testing.T) {
 	for i := 0; i < size; i++ {
 		data[i] = rand.Int()
 	}
-	queue := New(nil)
+	queue := New[int, int](nil)
+
 	for rep := 0; rep < 2; rep++ {
 		// Fill a priority queue with the above data
 		for i := 0; i < size; i++ {
-			queue.Push(data[i], int64(prio[i]))
+			queue.Push(data[i], prio[i])
 			if queue.Size() != i+1 {
 				t.Errorf("queue size mismatch: have %v, want %v.", queue.Size(), i+1)
 			}
 		}
 		// Create a map the values to the priorities for easier verification
-		dict := make(map[int64]int)
+		dict := make(map[int]int)
 		for i := 0; i < size; i++ {
-			dict[int64(prio[i])] = data[i]
+			dict[prio[i]] = data[i]
 		}
+
 		// Pop out the elements in priority order and verify them
-		prevPrio := int64(size + 1)
+		prevPrio := size + 1
 		for !queue.Empty() {
 			val, prio := queue.Pop()
 			if prio > prevPrio {
@@ -59,22 +61,23 @@ func TestReset(t *testing.T) {
 	for i := 0; i < size; i++ {
 		data[i] = rand.Int()
 	}
-	queue := New(nil)
+	queue := New[int, int](nil)
+
 	for rep := 0; rep < 2; rep++ {
 		// Fill a priority queue with the above data
 		for i := 0; i < size; i++ {
-			queue.Push(data[i], int64(prio[i]))
+			queue.Push(data[i], prio[i])
 			if queue.Size() != i+1 {
 				t.Errorf("queue size mismatch: have %v, want %v.", queue.Size(), i+1)
 			}
 		}
 		// Create a map the values to the priorities for easier verification
-		dict := make(map[int64]int)
+		dict := make(map[int]int)
 		for i := 0; i < size; i++ {
-			dict[int64(prio[i])] = data[i]
+			dict[prio[i]] = data[i]
 		}
 		// Pop out half the elements in priority order and verify them
-		prevPrio := int64(size + 1)
+		prevPrio := size + 1
 		for i := 0; i < size/2; i++ {
 			val, prio := queue.Pop()
 			if prio > prevPrio {
@@ -104,7 +107,7 @@ func BenchmarkPush(b *testing.B) {
 	}
 	// Execute the benchmark
 	b.ResetTimer()
-	queue := New(nil)
+	queue := New[int64, int](nil)
 	for i := 0; i < len(data); i++ {
 		queue.Push(data[i], prio[i])
 	}
@@ -118,7 +121,7 @@ func BenchmarkPop(b *testing.B) {
 		data[i] = rand.Int()
 		prio[i] = rand.Int63()
 	}
-	queue := New(nil)
+	queue := New[int64, int](nil)
 	for i := 0; i < len(data); i++ {
 		queue.Push(data[i], prio[i])
 	}

common/prque/sstack.go

@@ -10,53 +10,50 @@
 
 package prque
 
+import "golang.org/x/exp/constraints"
+
 // The size of a block of data
 const blockSize = 4096
 
 // A prioritized item in the sorted stack.
-//
+type item[P constraints.Ordered, V any] struct {
-// Note: priorities can "wrap around" the int64 range, a comes before b if (a.priority - b.priority) > 0.
+	value    V
-// The difference between the lowest and highest priorities in the queue at any point should be less than 2^63.
+	priority P
-type item struct {
-	value    interface{}
-	priority int64
 }
 
 // SetIndexCallback is called when the element is moved to a new index.
 // Providing SetIndexCallback is optional, it is needed only if the application needs
 // to delete elements other than the top one.
-type SetIndexCallback func(data interface{}, index int)
+type SetIndexCallback[V any] func(data V, index int)
 
 // Internal sortable stack data structure. Implements the Push and Pop ops for
 // the stack (heap) functionality and the Len, Less and Swap methods for the
 // sortability requirements of the heaps.
-type sstack struct {
+type sstack[P constraints.Ordered, V any] struct {
-	setIndex   SetIndexCallback
+	setIndex SetIndexCallback[V]
-	size       int
+	size     int
-	capacity   int
+	capacity int
-	offset     int
+	offset   int
-	wrapAround bool
 
-	blocks [][]*item
+	blocks [][]*item[P, V]
-	active []*item
+	active []*item[P, V]
 }
 
 // Creates a new, empty stack.
-func newSstack(setIndex SetIndexCallback, wrapAround bool) *sstack {
+func newSstack[P constraints.Ordered, V any](setIndex SetIndexCallback[V]) *sstack[P, V] {
-	result := new(sstack)
+	result := new(sstack[P, V])
 	result.setIndex = setIndex
-	result.active = make([]*item, blockSize)
+	result.active = make([]*item[P, V], blockSize)
-	result.blocks = [][]*item{result.active}
+	result.blocks = [][]*item[P, V]{result.active}
 	result.capacity = blockSize
-	result.wrapAround = wrapAround
 	return result
 }
 
 // Pushes a value onto the stack, expanding it if necessary. Required by
 // heap.Interface.
-func (s *sstack) Push(data interface{}) {
+func (s *sstack[P, V]) Push(data any) {
 	if s.size == s.capacity {
-		s.active = make([]*item, blockSize)
+		s.active = make([]*item[P, V], blockSize)
 		s.blocks = append(s.blocks, s.active)
 		s.capacity += blockSize
 		s.offset = 0
@@ -65,16 +62,16 @@ func (s *sstack) Push(data interface{}) {
 		s.offset = 0
 	}
 	if s.setIndex != nil {
-		s.setIndex(data.(*item).value, s.size)
+		s.setIndex(data.(*item[P, V]).value, s.size)
 	}
-	s.active[s.offset] = data.(*item)
+	s.active[s.offset] = data.(*item[P, V])
 	s.offset++
 	s.size++
 }
 
 // Pops a value off the stack and returns it. Currently no shrinking is done.
 // Required by heap.Interface.
-func (s *sstack) Pop() (res interface{}) {
+func (s *sstack[P, V]) Pop() (res any) {
 	s.size--
 	s.offset--
 	if s.offset < 0 {
@@ -83,28 +80,24 @@ func (s *sstack) Pop() (res interface{}) {
 	}
 	res, s.active[s.offset] = s.active[s.offset], nil
 	if s.setIndex != nil {
-		s.setIndex(res.(*item).value, -1)
+		s.setIndex(res.(*item[P, V]).value, -1)
 	}
 	return
 }
 
 // Returns the length of the stack. Required by sort.Interface.
-func (s *sstack) Len() int {
+func (s *sstack[P, V]) Len() int {
 	return s.size
 }
 
 // Compares the priority of two elements of the stack (higher is first).
 // Required by sort.Interface.
-func (s *sstack) Less(i, j int) bool {
+func (s *sstack[P, V]) Less(i, j int) bool {
-	a, b := s.blocks[i/blockSize][i%blockSize].priority, s.blocks[j/blockSize][j%blockSize].priority
+	return s.blocks[i/blockSize][i%blockSize].priority > s.blocks[j/blockSize][j%blockSize].priority
-	if s.wrapAround {
-		return a-b > 0
-	}
-	return a > b
 }
 
 // Swaps two elements in the stack. Required by sort.Interface.
-func (s *sstack) Swap(i, j int) {
+func (s *sstack[P, V]) Swap(i, j int) {
 	ib, io, jb, jo := i/blockSize, i%blockSize, j/blockSize, j%blockSize
 	a, b := s.blocks[jb][jo], s.blocks[ib][io]
 	if s.setIndex != nil {
@@ -115,6 +108,6 @@ func (s *sstack) Swap(i, j int) {
 }
 
 // Resets the stack, effectively clearing its contents.
-func (s *sstack) Reset() {
+func (s *sstack[P, V]) Reset() {
-	*s = *newSstack(s.setIndex, false)
+	*s = *newSstack[P, V](s.setIndex)
 }

common/prque/sstack_test.go

@@ -17,23 +17,23 @@ import (
 func TestSstack(t *testing.T) {
 	// Create some initial data
 	size := 16 * blockSize
-	data := make([]*item, size)
+	data := make([]*item[int64, int], size)
 	for i := 0; i < size; i++ {
-		data[i] = &item{rand.Int(), rand.Int63()}
+		data[i] = &item[int64, int]{rand.Int(), rand.Int63()}
 	}
-	stack := newSstack(nil, false)
+	stack := newSstack[int64, int](nil)
 	for rep := 0; rep < 2; rep++ {
 		// Push all the data into the stack, pop out every second
-		secs := []*item{}
+		secs := []*item[int64, int]{}
 		for i := 0; i < size; i++ {
 			stack.Push(data[i])
 			if i%2 == 0 {
-				secs = append(secs, stack.Pop().(*item))
+				secs = append(secs, stack.Pop().(*item[int64, int]))
 			}
 		}
-		rest := []*item{}
+		rest := []*item[int64, int]{}
 		for stack.Len() > 0 {
-			rest = append(rest, stack.Pop().(*item))
+			rest = append(rest, stack.Pop().(*item[int64, int]))
 		}
 		// Make sure the contents of the resulting slices are ok
 		for i := 0; i < size; i++ {
@@ -50,12 +50,12 @@ func TestSstack(t *testing.T) {
 func TestSstackSort(t *testing.T) {
 	// Create some initial data
 	size := 16 * blockSize
-	data := make([]*item, size)
+	data := make([]*item[int64, int], size)
 	for i := 0; i < size; i++ {
-		data[i] = &item{rand.Int(), int64(i)}
+		data[i] = &item[int64, int]{rand.Int(), int64(i)}
 	}
 	// Push all the data into the stack
-	stack := newSstack(nil, false)
+	stack := newSstack[int64, int](nil)
 	for _, val := range data {
 		stack.Push(val)
 	}
@@ -72,18 +72,18 @@ func TestSstackSort(t *testing.T) {
 func TestSstackReset(t *testing.T) {
 	// Create some initial data
 	size := 16 * blockSize
-	data := make([]*item, size)
+	data := make([]*item[int64, int], size)
 	for i := 0; i < size; i++ {
-		data[i] = &item{rand.Int(), rand.Int63()}
+		data[i] = &item[int64, int]{rand.Int(), rand.Int63()}
 	}
-	stack := newSstack(nil, false)
+	stack := newSstack[int64, int](nil)
 	for rep := 0; rep < 2; rep++ {
 		// Push all the data into the stack, pop out every second
-		secs := []*item{}
+		secs := []*item[int64, int]{}
 		for i := 0; i < size; i++ {
 			stack.Push(data[i])
 			if i%2 == 0 {
-				secs = append(secs, stack.Pop().(*item))
+				secs = append(secs, stack.Pop().(*item[int64, int]))
 			}
 		}
 		// Reset and verify both pulled and stack contents

core/blockchain.go

@@ -169,14 +169,14 @@ type BlockChain struct {
 	chainConfig *params.ChainConfig // Chain & network configuration
 	cacheConfig *CacheConfig        // Cache configuration for pruning
 
-	db            ethdb.Database // Low level persistent database to store final content in
+	db            ethdb.Database                   // Low level persistent database to store final content in
-	snaps         *snapshot.Tree // Snapshot tree for fast trie leaf access
+	snaps         *snapshot.Tree                   // Snapshot tree for fast trie leaf access
-	triegc        *prque.Prque   // Priority queue mapping block numbers to tries to gc
+	triegc        *prque.Prque[int64, common.Hash] // Priority queue mapping block numbers to tries to gc
-	gcproc        time.Duration  // Accumulates canonical block processing for trie dumping
+	gcproc        time.Duration                    // Accumulates canonical block processing for trie dumping
-	lastWrite     uint64         // Last block when the state was flushed
+	lastWrite     uint64                           // Last block when the state was flushed
-	flushInterval int64          // Time interval (processing time) after which to flush a state
+	flushInterval int64                            // Time interval (processing time) after which to flush a state
-	triedb        *trie.Database // The database handler for maintaining trie nodes.
+	triedb        *trie.Database                   // The database handler for maintaining trie nodes.
-	stateCache    state.Database // State database to reuse between imports (contains state cache)
+	stateCache    state.Database                   // State database to reuse between imports (contains state cache)
 
 	// txLookupLimit is the maximum number of blocks from head whose tx indices
 	// are reserved:
@@ -261,7 +261,7 @@ func NewBlockChain(db ethdb.Database, cacheConfig *CacheConfig, genesis *Genesis
 		db:            db,
 		triedb:        triedb,
 		flushInterval: int64(cacheConfig.TrieTimeLimit),
-		triegc:        prque.New(nil),
+		triegc:        prque.New[int64, common.Hash](nil),
 		quit:          make(chan struct{}),
 		chainmu:       syncx.NewClosableMutex(),
 		bodyCache:     lru.NewCache[common.Hash, *types.Body](bodyCacheLimit),
@@ -957,7 +957,7 @@ func (bc *BlockChain) Stop() {
 			}
 		}
 		for !bc.triegc.Empty() {
-			triedb.Dereference(bc.triegc.PopItem().(common.Hash))
+			triedb.Dereference(bc.triegc.PopItem())
 		}
 		if size, _ := triedb.Size(); size != 0 {
 			log.Error("Dangling trie nodes after full cleanup")
@@ -1391,7 +1391,7 @@ func (bc *BlockChain) writeBlockWithState(block *types.Block, receipts []*types.
 			bc.triegc.Push(root, number)
 			break
 		}
-		bc.triedb.Dereference(root.(common.Hash))
+		bc.triedb.Dereference(root)
 	}
 	return nil
 }

core/rawdb/chain_iterator.go

@@ -191,7 +191,7 @@ func indexTransactions(db ethdb.Database, from uint64, to uint64, interrupt chan
 		// in to be [to-1]. Therefore, setting lastNum to means that the
 		// prqueue gap-evaluation will work correctly
 		lastNum = to
-		queue   = prque.New(nil)
+		queue   = prque.New[int64, *blockTxHashes](nil)
 		// for stats reporting
 		blocks, txs = 0, 0
 	)
@@ -210,7 +210,7 @@ func indexTransactions(db ethdb.Database, from uint64, to uint64, interrupt chan
 				break
 			}
 			// Next block available, pop it off and index it
-			delivery := queue.PopItem().(*blockTxHashes)
+			delivery := queue.PopItem()
 			lastNum = delivery.number
 			WriteTxLookupEntries(batch, delivery.number, delivery.hashes)
 			blocks++
@@ -282,7 +282,7 @@ func unindexTransactions(db ethdb.Database, from uint64, to uint64, interrupt ch
 		// we expect the first number to come in to be [from]. Therefore, setting
 		// nextNum to from means that the prqueue gap-evaluation will work correctly
 		nextNum = from
-		queue   = prque.New(nil)
+		queue   = prque.New[int64, *blockTxHashes](nil)
 		// for stats reporting
 		blocks, txs = 0, 0
 	)
@@ -299,7 +299,7 @@ func unindexTransactions(db ethdb.Database, from uint64, to uint64, interrupt ch
 			if hook != nil && !hook(nextNum) {
 				break
 			}
-			delivery := queue.PopItem().(*blockTxHashes)
+			delivery := queue.PopItem()
 			nextNum = delivery.number + 1
 			DeleteTxLookupEntries(batch, delivery.hashes)
 			txs += len(delivery.hashes)

core/txpool/txpool.go

@@ -1395,7 +1395,7 @@ func (pool *TxPool) truncatePending() {
 
 	pendingBeforeCap := pending
 	// Assemble a spam order to penalize large transactors first
-	spammers := prque.New(nil)
+	spammers := prque.New[int64, common.Address](nil)
 	for addr, list := range pool.pending {
 		// Only evict transactions from high rollers
 		if !pool.locals.contains(addr) && uint64(list.Len()) > pool.config.AccountSlots {
@@ -1407,12 +1407,12 @@ func (pool *TxPool) truncatePending() {
 	for pending > pool.config.GlobalSlots && !spammers.Empty() {
 		// Retrieve the next offender if not local address
 		offender, _ := spammers.Pop()
-		offenders = append(offenders, offender.(common.Address))
+		offenders = append(offenders, offender)
 
 		// Equalize balances until all the same or below threshold
 		if len(offenders) > 1 {
 			// Calculate the equalization threshold for all current offenders
-			threshold := pool.pending[offender.(common.Address)].Len()
+			threshold := pool.pending[offender].Len()
 
 			// Iteratively reduce all offenders until below limit or threshold reached
 			for pending > pool.config.GlobalSlots && pool.pending[offenders[len(offenders)-2]].Len() > threshold {

eth/downloader/fetchers_concurrent.go

@@ -91,8 +91,8 @@ func (d *Downloader) concurrentFetch(queue typedQueue, beaconMode bool) error {
 		}
 	}()
 	ordering := make(map[*eth.Request]int)
-	timeouts := prque.New(func(data interface{}, index int) {
+	timeouts := prque.New[int64, *eth.Request](func(data *eth.Request, index int) {
-		ordering[data.(*eth.Request)] = index
+		ordering[data] = index
 	})
 
 	timeout := time.NewTimer(0)
@@ -268,14 +268,12 @@ func (d *Downloader) concurrentFetch(queue typedQueue, beaconMode bool) error {
 			// below is purely for to catch programming errors, given the correct
 			// code, there's no possible order of events that should result in a
 			// timeout firing for a non-existent event.
-			item, exp := timeouts.Peek()
+			req, exp := timeouts.Peek()
 			if now, at := time.Now(), time.Unix(0, -exp); now.Before(at) {
 				log.Error("Timeout triggered but not reached", "left", at.Sub(now))
 				timeout.Reset(at.Sub(now))
 				continue
 			}
-			req := item.(*eth.Request)
-
 			// Stop tracking the timed out request from a timing perspective,
 			// cancel it, so it's not considered in-flight anymore, but keep
 			// the peer marked busy to prevent assigning a second request and

eth/downloader/queue.go

@@ -115,7 +115,7 @@ type queue struct {
 	// Headers are "special", they download in batches, supported by a skeleton chain
 	headerHead      common.Hash                    // Hash of the last queued header to verify order
 	headerTaskPool  map[uint64]*types.Header       // Pending header retrieval tasks, mapping starting indexes to skeleton headers
-	headerTaskQueue *prque.Prque                   // Priority queue of the skeleton indexes to fetch the filling headers for
+	headerTaskQueue *prque.Prque[int64, uint64]    // Priority queue of the skeleton indexes to fetch the filling headers for
 	headerPeerMiss  map[string]map[uint64]struct{} // Set of per-peer header batches known to be unavailable
 	headerPendPool  map[string]*fetchRequest       // Currently pending header retrieval operations
 	headerResults   []*types.Header                // Result cache accumulating the completed headers
@@ -125,15 +125,15 @@ type queue struct {
 	headerContCh    chan bool                      // Channel to notify when header download finishes
 
 	// All data retrievals below are based on an already assembles header chain
-	blockTaskPool  map[common.Hash]*types.Header // Pending block (body) retrieval tasks, mapping hashes to headers
+	blockTaskPool  map[common.Hash]*types.Header      // Pending block (body) retrieval tasks, mapping hashes to headers
-	blockTaskQueue *prque.Prque                  // Priority queue of the headers to fetch the blocks (bodies) for
+	blockTaskQueue *prque.Prque[int64, *types.Header] // Priority queue of the headers to fetch the blocks (bodies) for
-	blockPendPool  map[string]*fetchRequest      // Currently pending block (body) retrieval operations
+	blockPendPool  map[string]*fetchRequest           // Currently pending block (body) retrieval operations
-	blockWakeCh    chan bool                     // Channel to notify the block fetcher of new tasks
+	blockWakeCh    chan bool                          // Channel to notify the block fetcher of new tasks
 
-	receiptTaskPool  map[common.Hash]*types.Header // Pending receipt retrieval tasks, mapping hashes to headers
+	receiptTaskPool  map[common.Hash]*types.Header      // Pending receipt retrieval tasks, mapping hashes to headers
-	receiptTaskQueue *prque.Prque                  // Priority queue of the headers to fetch the receipts for
+	receiptTaskQueue *prque.Prque[int64, *types.Header] // Priority queue of the headers to fetch the receipts for
-	receiptPendPool  map[string]*fetchRequest      // Currently pending receipt retrieval operations
+	receiptPendPool  map[string]*fetchRequest           // Currently pending receipt retrieval operations
-	receiptWakeCh    chan bool                     // Channel to notify when receipt fetcher of new tasks
+	receiptWakeCh    chan bool                          // Channel to notify when receipt fetcher of new tasks
 
 	resultCache *resultStore       // Downloaded but not yet delivered fetch results
 	resultSize  common.StorageSize // Approximate size of a block (exponential moving average)
@@ -150,9 +150,9 @@ func newQueue(blockCacheLimit int, thresholdInitialSize int) *queue {
 	lock := new(sync.RWMutex)
 	q := &queue{
 		headerContCh:     make(chan bool, 1),
-		blockTaskQueue:   prque.New(nil),
+		blockTaskQueue:   prque.New[int64, *types.Header](nil),
 		blockWakeCh:      make(chan bool, 1),
-		receiptTaskQueue: prque.New(nil),
+		receiptTaskQueue: prque.New[int64, *types.Header](nil),
 		receiptWakeCh:    make(chan bool, 1),
 		active:           sync.NewCond(lock),
 		lock:             lock,
@@ -258,7 +258,7 @@ func (q *queue) ScheduleSkeleton(from uint64, skeleton []*types.Header) {
 	}
 	// Schedule all the header retrieval tasks for the skeleton assembly
 	q.headerTaskPool = make(map[uint64]*types.Header)
-	q.headerTaskQueue = prque.New(nil)
+	q.headerTaskQueue = prque.New[int64, uint64](nil)
 	q.headerPeerMiss = make(map[string]map[uint64]struct{}) // Reset availability to correct invalid chains
 	q.headerResults = make([]*types.Header, len(skeleton)*MaxHeaderFetch)
 	q.headerHashes = make([]common.Hash, len(skeleton)*MaxHeaderFetch)
@@ -428,12 +428,12 @@ func (q *queue) ReserveHeaders(p *peerConnection, count int) *fetchRequest {
 	for send == 0 && !q.headerTaskQueue.Empty() {
 		from, _ := q.headerTaskQueue.Pop()
 		if q.headerPeerMiss[p.id] != nil {
-			if _, ok := q.headerPeerMiss[p.id][from.(uint64)]; ok {
+			if _, ok := q.headerPeerMiss[p.id][from]; ok {
-				skip = append(skip, from.(uint64))
+				skip = append(skip, from)
 				continue
 			}
 		}
-		send = from.(uint64)
+		send = from
 	}
 	// Merge all the skipped batches back
 	for _, from := range skip {
@@ -485,7 +485,7 @@ func (q *queue) ReserveReceipts(p *peerConnection, count int) (*fetchRequest, bo
 //	item     - the fetchRequest
 //	progress - whether any progress was made
 //	throttle - if the caller should throttle for a while
-func (q *queue) reserveHeaders(p *peerConnection, count int, taskPool map[common.Hash]*types.Header, taskQueue *prque.Prque,
+func (q *queue) reserveHeaders(p *peerConnection, count int, taskPool map[common.Hash]*types.Header, taskQueue *prque.Prque[int64, *types.Header],
 	pendPool map[string]*fetchRequest, kind uint) (*fetchRequest, bool, bool) {
 	// Short circuit if the pool has been depleted, or if the peer's already
 	// downloading something (sanity check not to corrupt state)
@@ -503,8 +503,8 @@ func (q *queue) reserveHeaders(p *peerConnection, count int, taskPool map[common
 	for proc := 0; len(send) < count && !taskQueue.Empty(); proc++ {
 		// the task queue will pop items in order, so the highest prio block
 		// is also the lowest block number.
-		h, _ := taskQueue.Peek()
+		header, _ := taskQueue.Peek()
-		header := h.(*types.Header)
+
 		// we can ask the resultcache if this header is within the
 		// "prioritized" segment of blocks. If it is not, we need to throttle
 
@@ -627,12 +627,14 @@ func (q *queue) ExpireReceipts(peer string) int {
 }
 
 // expire is the generic check that moves a specific expired task from a pending
-// pool back into a task pool.
+// pool back into a task pool. The syntax on the passed taskQueue is a bit weird
+// as we would need a generic expire method to handle both types, but that is not
+// supported at the moment at least (Go 1.19).
 //
 // Note, this method expects the queue lock to be already held. The reason the
 // lock is not obtained in here is that the parameters already need to access
 // the queue, so they already need a lock anyway.
-func (q *queue) expire(peer string, pendPool map[string]*fetchRequest, taskQueue *prque.Prque) int {
+func (q *queue) expire(peer string, pendPool map[string]*fetchRequest, taskQueue interface{}) int {
 	// Retrieve the request being expired and log an error if it's non-existent,
 	// as there's no order of events that should lead to such expirations.
 	req := pendPool[peer]
@@ -644,10 +646,10 @@ func (q *queue) expire(peer string, pendPool map[string]*fetchRequest, taskQueue
 
 	// Return any non-satisfied requests to the pool
 	if req.From > 0 {
-		taskQueue.Push(req.From, -int64(req.From))
+		taskQueue.(*prque.Prque[int64, uint64]).Push(req.From, -int64(req.From))
 	}
 	for _, header := range req.Headers {
-		taskQueue.Push(header, -int64(header.Number.Uint64()))
+		taskQueue.(*prque.Prque[int64, *types.Header]).Push(header, -int64(header.Number.Uint64()))
 	}
 	return len(req.Headers)
 }
@@ -824,7 +826,7 @@ func (q *queue) DeliverReceipts(id string, receiptList [][]*types.Receipt, recei
 // reason this lock is not obtained in here is because the parameters already need
 // to access the queue, so they already need a lock anyway.
 func (q *queue) deliver(id string, taskPool map[common.Hash]*types.Header,
-	taskQueue *prque.Prque, pendPool map[string]*fetchRequest,
+	taskQueue *prque.Prque[int64, *types.Header], pendPool map[string]*fetchRequest,
 	reqTimer metrics.Timer, resInMeter metrics.Meter, resDropMeter metrics.Meter,
 	results int, validate func(index int, header *types.Header) error,
 	reconstruct func(index int, result *fetchResult)) (int, error) {

eth/fetcher/block_fetcher.go

@@ -175,9 +175,9 @@ type BlockFetcher struct {
 	completing map[common.Hash]*blockAnnounce   // Blocks with headers, currently body-completing
 
 	// Block cache
-	queue  *prque.Prque                         // Queue containing the import operations (block number sorted)
+	queue  *prque.Prque[int64, *blockOrHeaderInject] // Queue containing the import operations (block number sorted)
-	queues map[string]int                       // Per peer block counts to prevent memory exhaustion
+	queues map[string]int                            // Per peer block counts to prevent memory exhaustion
-	queued map[common.Hash]*blockOrHeaderInject // Set of already queued blocks (to dedup imports)
+	queued map[common.Hash]*blockOrHeaderInject      // Set of already queued blocks (to dedup imports)
 
 	// Callbacks
 	getHeader      HeaderRetrievalFn  // Retrieves a header from the local chain
@@ -212,7 +212,7 @@ func NewBlockFetcher(light bool, getHeader HeaderRetrievalFn, getBlock blockRetr
 		fetching:       make(map[common.Hash]*blockAnnounce),
 		fetched:        make(map[common.Hash][]*blockAnnounce),
 		completing:     make(map[common.Hash]*blockAnnounce),
-		queue:          prque.New(nil),
+		queue:          prque.New[int64, *blockOrHeaderInject](nil),
 		queues:         make(map[string]int),
 		queued:         make(map[common.Hash]*blockOrHeaderInject),
 		getHeader:      getHeader,
@@ -351,7 +351,7 @@ func (f *BlockFetcher) loop() {
 		// Import any queued blocks that could potentially fit
 		height := f.chainHeight()
 		for !f.queue.Empty() {
-			op := f.queue.PopItem().(*blockOrHeaderInject)
+			op := f.queue.PopItem()
 			hash := op.hash()
 			if f.queueChangeHook != nil {
 				f.queueChangeHook(hash, false)

go.mod

@@ -59,11 +59,12 @@ require (
 	github.com/tyler-smith/go-bip39 v1.1.0
 	github.com/urfave/cli/v2 v2.17.2-0.20221006022127-8f469abc00aa
 	golang.org/x/crypto v0.1.0
+	golang.org/x/exp v0.0.0-20221126150942-6ab00d035af9
 	golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4
 	golang.org/x/sys v0.3.0
 	golang.org/x/text v0.4.0
 	golang.org/x/time v0.0.0-20210220033141-f8bda1e9f3ba
-	golang.org/x/tools v0.1.12
+	golang.org/x/tools v0.2.0
 	gopkg.in/natefinch/npipe.v2 v2.0.0-20160621034901-c1b8fa8bdcce
 )
 
@@ -116,8 +117,7 @@ require (
 	github.com/tklauser/go-sysconf v0.3.5 // indirect
 	github.com/tklauser/numcpus v0.2.2 // indirect
 	github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673 // indirect
-	golang.org/x/exp v0.0.0-20220426173459-3bcf042a4bf5 // indirect
+	golang.org/x/mod v0.6.0 // indirect
-	golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4 // indirect
 	golang.org/x/net v0.1.0 // indirect
 	golang.org/x/xerrors v0.0.0-20220517211312-f3a8303e98df // indirect
 	google.golang.org/protobuf v1.27.1 // indirect

go.sum

@@ -298,7 +298,7 @@ github.com/google/go-cmp v0.5.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/
 github.com/google/go-cmp v0.5.1/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.4/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
-github.com/google/go-cmp v0.5.6 h1:BKbKCqvP6I+rmFHt06ZmyQtvB8xAkWdhFyr0ZUNZcxQ=
+github.com/google/go-cmp v0.5.8 h1:e6P7q2lk1O+qJJb4BtCQXlK8vWEO8V1ZeuEdJNOqZyg=
 github.com/google/go-querystring v1.0.0/go.mod h1:odCYkC5MyYFN7vkCjXpyrEuKhc/BUO6wN/zVPAxq5ck=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
 github.com/google/gofuzz v1.1.1-0.20200604201612-c04b05f3adfa h1:Q75Upo5UN4JbPFURXZ8nLKYUvF85dyFRop/vQ0Rv+64=
@@ -657,8 +657,8 @@ golang.org/x/exp v0.0.0-20191227195350-da58074b4299/go.mod h1:2RIsYlXP63K8oxa1u0
 golang.org/x/exp v0.0.0-20200119233911-0405dc783f0a/go.mod h1:2RIsYlXP63K8oxa1u096TMicItID8zy7Y6sNkU49FU4=
 golang.org/x/exp v0.0.0-20200207192155-f17229e696bd/go.mod h1:J/WKrq2StrnmMY6+EHIKF9dgMWnmCNThgcyBT1FY9mM=
 golang.org/x/exp v0.0.0-20200224162631-6cc2880d07d6/go.mod h1:3jZMyOhIsHpP37uCMkUooju7aAi5cS1Q23tOzKc+0MU=
-golang.org/x/exp v0.0.0-20220426173459-3bcf042a4bf5 h1:rxKZ2gOnYxjfmakvUUqh9Gyb6KXfrj7JWTxORTYqb0E=
+golang.org/x/exp v0.0.0-20221126150942-6ab00d035af9 h1:yZNXmy+j/JpX19vZkVktWqAo7Gny4PBWYYK3zskGpx4=
-golang.org/x/exp v0.0.0-20220426173459-3bcf042a4bf5/go.mod h1:lgLbSvA5ygNOMpwM/9anMpWVlVJ7Z+cHWq/eFuinpGE=
+golang.org/x/exp v0.0.0-20221126150942-6ab00d035af9/go.mod h1:CxIveKay+FTh1D0yPZemJVgC/95VzuuOLq5Qi4xnoYc=
 golang.org/x/image v0.0.0-20180708004352-c73c2afc3b81/go.mod h1:ux5Hcp/YLpHSI86hEcLt0YII63i6oz57MZXIpbrjZUs=
 golang.org/x/image v0.0.0-20190227222117-0694c2d4d067/go.mod h1:kZ7UVZpmo3dzQBMxlp+ypCbDeSB+sBbTgSJuh5dn5js=
 golang.org/x/image v0.0.0-20190802002840-cff245a6509b/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
@@ -680,8 +680,8 @@ golang.org/x/mod v0.1.1-0.20191105210325-c90efee705ee/go.mod h1:QqPTAvyqsEbceGzB
 golang.org/x/mod v0.1.1-0.20191107180719-034126e5016b/go.mod h1:QqPTAvyqsEbceGzBzNggFXnrqF1CaUcvgkdR5Ot7KZg=
 golang.org/x/mod v0.2.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
-golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4 h1:6zppjxzCulZykYSLyVDYbneBfbaBIQPYMevg0bEwv2s=
+golang.org/x/mod v0.6.0 h1:b9gGHsz9/HhJ3HF5DHQytPpuwocVTChQJK3AvoLRD5I=
-golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
+golang.org/x/mod v0.6.0/go.mod h1:4mET923SAdbXp2ki8ey+zGs1SLqsuM2Y0uvdZR/fUNI=
 golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180906233101-161cd47e91fd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
@@ -872,8 +872,8 @@ golang.org/x/tools v0.0.0-20200729194436-6467de6f59a7/go.mod h1:njjCfa9FT2d7l9Bc
 golang.org/x/tools v0.0.0-20200804011535-6c149bb5ef0d/go.mod h1:njjCfa9FT2d7l9Bc6FUM5FLjQPp3cFF28FI3qnDFljA=
 golang.org/x/tools v0.0.0-20200825202427-b303f430e36d/go.mod h1:njjCfa9FT2d7l9Bc6FUM5FLjQPp3cFF28FI3qnDFljA=
 golang.org/x/tools v0.0.0-20210106214847-113979e3529a/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
-golang.org/x/tools v0.1.12 h1:VveCTK38A2rkS8ZqFY25HIDFscX5X9OoEhJd3quQmXU=
+golang.org/x/tools v0.2.0 h1:G6AHpWxTMGY1KyEYoAQ5WTtIekUUvDNjan3ugu60JvE=
-golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc=
+golang.org/x/tools v0.2.0/go.mod h1:y4OqIKeOV/fWJetJ8bXPU1sEVniLMIyDAZWeHdV+NTA=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

les/downloader/queue.go

@@ -115,7 +115,7 @@ type queue struct {
 	// Headers are "special", they download in batches, supported by a skeleton chain
 	headerHead      common.Hash                    // Hash of the last queued header to verify order
 	headerTaskPool  map[uint64]*types.Header       // Pending header retrieval tasks, mapping starting indexes to skeleton headers
-	headerTaskQueue *prque.Prque                   // Priority queue of the skeleton indexes to fetch the filling headers for
+	headerTaskQueue *prque.Prque[int64, uint64]    // Priority queue of the skeleton indexes to fetch the filling headers for
 	headerPeerMiss  map[string]map[uint64]struct{} // Set of per-peer header batches known to be unavailable
 	headerPendPool  map[string]*fetchRequest       // Currently pending header retrieval operations
 	headerResults   []*types.Header                // Result cache accumulating the completed headers
@@ -124,13 +124,13 @@ type queue struct {
 	headerContCh    chan bool                      // Channel to notify when header download finishes
 
 	// All data retrievals below are based on an already assembles header chain
-	blockTaskPool  map[common.Hash]*types.Header // Pending block (body) retrieval tasks, mapping hashes to headers
+	blockTaskPool  map[common.Hash]*types.Header      // Pending block (body) retrieval tasks, mapping hashes to headers
-	blockTaskQueue *prque.Prque                  // Priority queue of the headers to fetch the blocks (bodies) for
+	blockTaskQueue *prque.Prque[int64, *types.Header] // Priority queue of the headers to fetch the blocks (bodies) for
-	blockPendPool  map[string]*fetchRequest      // Currently pending block (body) retrieval operations
+	blockPendPool  map[string]*fetchRequest           // Currently pending block (body) retrieval operations
 
-	receiptTaskPool  map[common.Hash]*types.Header // Pending receipt retrieval tasks, mapping hashes to headers
+	receiptTaskPool  map[common.Hash]*types.Header      // Pending receipt retrieval tasks, mapping hashes to headers
-	receiptTaskQueue *prque.Prque                  // Priority queue of the headers to fetch the receipts for
+	receiptTaskQueue *prque.Prque[int64, *types.Header] // Priority queue of the headers to fetch the receipts for
-	receiptPendPool  map[string]*fetchRequest      // Currently pending receipt retrieval operations
+	receiptPendPool  map[string]*fetchRequest           // Currently pending receipt retrieval operations
 
 	resultCache *resultStore       // Downloaded but not yet delivered fetch results
 	resultSize  common.StorageSize // Approximate size of a block (exponential moving average)
@@ -147,8 +147,8 @@ func newQueue(blockCacheLimit int, thresholdInitialSize int) *queue {
 	lock := new(sync.RWMutex)
 	q := &queue{
 		headerContCh:     make(chan bool),
-		blockTaskQueue:   prque.New(nil),
+		blockTaskQueue:   prque.New[int64, *types.Header](nil),
-		receiptTaskQueue: prque.New(nil),
+		receiptTaskQueue: prque.New[int64, *types.Header](nil),
 		active:           sync.NewCond(lock),
 		lock:             lock,
 	}
@@ -262,7 +262,7 @@ func (q *queue) ScheduleSkeleton(from uint64, skeleton []*types.Header) {
 	}
 	// Schedule all the header retrieval tasks for the skeleton assembly
 	q.headerTaskPool = make(map[uint64]*types.Header)
-	q.headerTaskQueue = prque.New(nil)
+	q.headerTaskQueue = prque.New[int64, uint64](nil)
 	q.headerPeerMiss = make(map[string]map[uint64]struct{}) // Reset availability to correct invalid chains
 	q.headerResults = make([]*types.Header, len(skeleton)*MaxHeaderFetch)
 	q.headerProced = 0
@@ -424,12 +424,12 @@ func (q *queue) ReserveHeaders(p *peerConnection, count int) *fetchRequest {
 	for send == 0 && !q.headerTaskQueue.Empty() {
 		from, _ := q.headerTaskQueue.Pop()
 		if q.headerPeerMiss[p.id] != nil {
-			if _, ok := q.headerPeerMiss[p.id][from.(uint64)]; ok {
+			if _, ok := q.headerPeerMiss[p.id][from]; ok {
-				skip = append(skip, from.(uint64))
+				skip = append(skip, from)
 				continue
 			}
 		}
-		send = from.(uint64)
+		send = from
 	}
 	// Merge all the skipped batches back
 	for _, from := range skip {
@@ -481,7 +481,7 @@ func (q *queue) ReserveReceipts(p *peerConnection, count int) (*fetchRequest, bo
 //	item     - the fetchRequest
 //	progress - whether any progress was made
 //	throttle - if the caller should throttle for a while
-func (q *queue) reserveHeaders(p *peerConnection, count int, taskPool map[common.Hash]*types.Header, taskQueue *prque.Prque,
+func (q *queue) reserveHeaders(p *peerConnection, count int, taskPool map[common.Hash]*types.Header, taskQueue *prque.Prque[int64, *types.Header],
 	pendPool map[string]*fetchRequest, kind uint) (*fetchRequest, bool, bool) {
 	// Short circuit if the pool has been depleted, or if the peer's already
 	// downloading something (sanity check not to corrupt state)
@@ -499,8 +499,8 @@ func (q *queue) reserveHeaders(p *peerConnection, count int, taskPool map[common
 	for proc := 0; len(send) < count && !taskQueue.Empty(); proc++ {
 		// the task queue will pop items in order, so the highest prio block
 		// is also the lowest block number.
-		h, _ := taskQueue.Peek()
+		header, _ := taskQueue.Peek()
-		header := h.(*types.Header)
+
 		// we can ask the resultcache if this header is within the
 		// "prioritized" segment of blocks. If it is not, we need to throttle
 
@@ -591,12 +591,12 @@ func (q *queue) CancelReceipts(request *fetchRequest) {
 }
 
 // Cancel aborts a fetch request, returning all pending hashes to the task queue.
-func (q *queue) cancel(request *fetchRequest, taskQueue *prque.Prque, pendPool map[string]*fetchRequest) {
+func (q *queue) cancel(request *fetchRequest, taskQueue interface{}, pendPool map[string]*fetchRequest) {
 	if request.From > 0 {
-		taskQueue.Push(request.From, -int64(request.From))
+		taskQueue.(*prque.Prque[int64, uint64]).Push(request.From, -int64(request.From))
 	}
 	for _, header := range request.Headers {
-		taskQueue.Push(header, -int64(header.Number.Uint64()))
+		taskQueue.(*prque.Prque[int64, *types.Header]).Push(header, -int64(header.Number.Uint64()))
 	}
 	delete(pendPool, request.Peer.id)
 }
@@ -655,7 +655,7 @@ func (q *queue) ExpireReceipts(timeout time.Duration) map[string]int {
 // Note, this method expects the queue lock to be already held. The
 // reason the lock is not obtained in here is because the parameters already need
 // to access the queue, so they already need a lock anyway.
-func (q *queue) expire(timeout time.Duration, pendPool map[string]*fetchRequest, taskQueue *prque.Prque, timeoutMeter metrics.Meter) map[string]int {
+func (q *queue) expire(timeout time.Duration, pendPool map[string]*fetchRequest, taskQueue interface{}, timeoutMeter metrics.Meter) map[string]int {
 	// Iterate over the expired requests and return each to the queue
 	expiries := make(map[string]int)
 	for id, request := range pendPool {
@@ -665,10 +665,10 @@ func (q *queue) expire(timeout time.Duration, pendPool map[string]*fetchRequest,
 
 			// Return any non satisfied requests to the pool
 			if request.From > 0 {
-				taskQueue.Push(request.From, -int64(request.From))
+				taskQueue.(*prque.Prque[int64, uint64]).Push(request.From, -int64(request.From))
 			}
 			for _, header := range request.Headers {
-				taskQueue.Push(header, -int64(header.Number.Uint64()))
+				taskQueue.(*prque.Prque[int64, *types.Header]).Push(header, -int64(header.Number.Uint64()))
 			}
 			// Add the peer to the expiry report along the number of failed requests
 			expiries[id] = len(request.Headers)
@@ -831,7 +831,7 @@ func (q *queue) DeliverReceipts(id string, receiptList [][]*types.Receipt) (int,
 // reason this lock is not obtained in here is because the parameters already need
 // to access the queue, so they already need a lock anyway.
 func (q *queue) deliver(id string, taskPool map[common.Hash]*types.Header,
-	taskQueue *prque.Prque, pendPool map[string]*fetchRequest, reqTimer metrics.Timer,
+	taskQueue *prque.Prque[int64, *types.Header], pendPool map[string]*fetchRequest, reqTimer metrics.Timer,
 	results int, validate func(index int, header *types.Header) error,
 	reconstruct func(index int, result *fetchResult)) (int, error) {
 	// Short circuit if the data was never requested

les/fetcher/block_fetcher.go

@@ -177,9 +177,9 @@ type BlockFetcher struct {
 	completing map[common.Hash]*blockAnnounce   // Blocks with headers, currently body-completing
 
 	// Block cache
-	queue  *prque.Prque                         // Queue containing the import operations (block number sorted)
+	queue  *prque.Prque[int64, *blockOrHeaderInject] // Queue containing the import operations (block number sorted)
-	queues map[string]int                       // Per peer block counts to prevent memory exhaustion
+	queues map[string]int                            // Per peer block counts to prevent memory exhaustion
-	queued map[common.Hash]*blockOrHeaderInject // Set of already queued blocks (to dedup imports)
+	queued map[common.Hash]*blockOrHeaderInject      // Set of already queued blocks (to dedup imports)
 
 	// Callbacks
 	getHeader      HeaderRetrievalFn  // Retrieves a header from the local chain
@@ -214,7 +214,7 @@ func NewBlockFetcher(light bool, getHeader HeaderRetrievalFn, getBlock blockRetr
 		fetching:       make(map[common.Hash]*blockAnnounce),
 		fetched:        make(map[common.Hash][]*blockAnnounce),
 		completing:     make(map[common.Hash]*blockAnnounce),
-		queue:          prque.New(nil),
+		queue:          prque.New[int64, *blockOrHeaderInject](nil),
 		queues:         make(map[string]int),
 		queued:         make(map[common.Hash]*blockOrHeaderInject),
 		getHeader:      getHeader,
@@ -353,7 +353,7 @@ func (f *BlockFetcher) loop() {
 		// Import any queued blocks that could potentially fit
 		height := f.chainHeight()
 		for !f.queue.Empty() {
-			op := f.queue.PopItem().(*blockOrHeaderInject)
+			op := f.queue.PopItem()
 			hash := op.hash()
 			if f.queueChangeHook != nil {
 				f.queueChangeHook(hash, false)

les/flowcontrol/manager.go

@@ -75,10 +75,11 @@ type ClientManager struct {
 	// (totalRecharge / sumRecharge)*FixedPointMultiplier or 0 if sumRecharge==0
 	rcLastUpdate   mclock.AbsTime // last time the recharge integrator was updated
 	rcLastIntValue int64          // last updated value of the recharge integrator
+	priorityOffset int64          // offset for prque priority values ensures that all priorities stay in the int64 range
 	// recharge queue is a priority queue with currently recharging client nodes
 	// as elements. The priority value is rcFullIntValue which allows to quickly
 	// determine which client will first finish recharge.
-	rcQueue *prque.Prque
+	rcQueue *prque.Prque[int64, *ClientNode]
 }
 
 // NewClientManager returns a new client manager.
@@ -107,7 +108,7 @@ type ClientManager struct {
 func NewClientManager(curve PieceWiseLinear, clock mclock.Clock) *ClientManager {
 	cm := &ClientManager{
 		clock:         clock,
-		rcQueue:       prque.NewWrapAround(func(a interface{}, i int) { a.(*ClientNode).queueIndex = i }),
+		rcQueue:       prque.New[int64, *ClientNode](func(a *ClientNode, i int) { a.queueIndex = i }),
 		capLastUpdate: clock.Now(),
 		stop:          make(chan chan struct{}),
 	}
@@ -288,13 +289,13 @@ func (cm *ClientManager) updateRecharge(now mclock.AbsTime) {
 		}
 		dt := now - lastUpdate
 		// fetch the client that finishes first
-		rcqNode := cm.rcQueue.PopItem().(*ClientNode) // if sumRecharge > 0 then the queue cannot be empty
+		rcqNode := cm.rcQueue.PopItem() // if sumRecharge > 0 then the queue cannot be empty
 		// check whether it has already finished
 		dtNext := mclock.AbsTime(float64(rcqNode.rcFullIntValue-cm.rcLastIntValue) / bonusRatio)
 		if dt < dtNext {
 			// not finished yet, put it back, update integrator according
 			// to current bonusRatio and return
-			cm.rcQueue.Push(rcqNode, -rcqNode.rcFullIntValue)
+			cm.addToQueue(rcqNode)
 			cm.rcLastIntValue += int64(bonusRatio * float64(dt))
 			return
 		}
@@ -308,6 +309,20 @@ func (cm *ClientManager) updateRecharge(now mclock.AbsTime) {
 	}
 }
 
+func (cm *ClientManager) addToQueue(node *ClientNode) {
+	if cm.priorityOffset-node.rcFullIntValue < -0x4000000000000000 {
+		cm.priorityOffset += 0x4000000000000000
+		// recreate priority queue with new offset to avoid overflow; should happen very rarely
+		newRcQueue := prque.New[int64, *ClientNode](func(a *ClientNode, i int) { a.queueIndex = i })
+		for cm.rcQueue.Size() > 0 {
+			n := cm.rcQueue.PopItem()
+			newRcQueue.Push(n, cm.priorityOffset-n.rcFullIntValue)
+		}
+		cm.rcQueue = newRcQueue
+	}
+	cm.rcQueue.Push(node, cm.priorityOffset-node.rcFullIntValue)
+}
+
 // updateNodeRc updates a node's corrBufValue and adds an external correction value.
 // It also adds or removes the rcQueue entry and updates ServerParams and sumRecharge if necessary.
 func (cm *ClientManager) updateNodeRc(node *ClientNode, bvc int64, params *ServerParams, now mclock.AbsTime) {
@@ -344,7 +359,7 @@ func (cm *ClientManager) updateNodeRc(node *ClientNode, bvc int64, params *Serve
 		}
 		node.rcLastIntValue = cm.rcLastIntValue
 		node.rcFullIntValue = cm.rcLastIntValue + (int64(node.params.BufLimit)-node.corrBufValue)*FixedPointMultiplier/int64(node.params.MinRecharge)
-		cm.rcQueue.Push(node, -node.rcFullIntValue)
+		cm.addToQueue(node)
 	}
 }
 

les/flowcontrol/manager_test.go

@@ -17,6 +17,7 @@
 package flowcontrol
 
 import (
+	"math"
 	"math/rand"
 	"testing"
 	"time"
@@ -44,16 +45,17 @@ const (
 // maximum permitted rate. The max capacity nodes are changed multiple times during
 // a single test.
 func TestConstantTotalCapacity(t *testing.T) {
-	testConstantTotalCapacity(t, 10, 1, 0)
+	testConstantTotalCapacity(t, 10, 1, 0, false)
-	testConstantTotalCapacity(t, 10, 1, 1)
+	testConstantTotalCapacity(t, 10, 1, 1, false)
-	testConstantTotalCapacity(t, 30, 1, 0)
+	testConstantTotalCapacity(t, 30, 1, 0, false)
-	testConstantTotalCapacity(t, 30, 2, 3)
+	testConstantTotalCapacity(t, 30, 2, 3, false)
-	testConstantTotalCapacity(t, 100, 1, 0)
+	testConstantTotalCapacity(t, 100, 1, 0, false)
-	testConstantTotalCapacity(t, 100, 3, 5)
+	testConstantTotalCapacity(t, 100, 3, 5, false)
-	testConstantTotalCapacity(t, 100, 5, 10)
+	testConstantTotalCapacity(t, 100, 5, 10, false)
+	testConstantTotalCapacity(t, 100, 3, 5, true)
 }
 
-func testConstantTotalCapacity(t *testing.T, nodeCount, maxCapacityNodes, randomSend int) {
+func testConstantTotalCapacity(t *testing.T, nodeCount, maxCapacityNodes, randomSend int, priorityOverflow bool) {
 	clock := &mclock.Simulated{}
 	nodes := make([]*testNode, nodeCount)
 	var totalCapacity uint64
@@ -62,6 +64,10 @@ func testConstantTotalCapacity(t *testing.T, nodeCount, maxCapacityNodes, random
 		totalCapacity += nodes[i].capacity
 	}
 	m := NewClientManager(PieceWiseLinear{{0, totalCapacity}}, clock)
+	if priorityOverflow {
+		// provoke a situation where rcLastUpdate overflow needs to be handled
+		m.rcLastIntValue = math.MaxInt64 - 10000000000
+	}
 	for _, n := range nodes {
 		n.bufLimit = n.capacity * 6000
 		n.node = NewClientNode(m, ServerParams{BufLimit: n.bufLimit, MinRecharge: n.capacity})

les/servingqueue.go

@@ -38,10 +38,10 @@ type servingQueue struct {
 	setThreadsCh            chan int
 
 	wg          sync.WaitGroup
-	threadCount int          // number of currently running threads
+	threadCount int                               // number of currently running threads
-	queue       *prque.Prque // priority queue for waiting or suspended tasks
+	queue       *prque.Prque[int64, *servingTask] // priority queue for waiting or suspended tasks
-	best        *servingTask // the highest priority task (not included in the queue)
+	best        *servingTask                      // the highest priority task (not included in the queue)
-	suspendBias int64        // priority bias against suspending an already running task
+	suspendBias int64                             // priority bias against suspending an already running task
 }
 
 // servingTask represents a request serving task. Tasks can be implemented to
@@ -123,7 +123,7 @@ func (t *servingTask) waitOrStop() bool {
 // newServingQueue returns a new servingQueue
 func newServingQueue(suspendBias int64, utilTarget float64) *servingQueue {
 	sq := &servingQueue{
-		queue:          prque.NewWrapAround(nil),
+		queue:          prque.New[int64, *servingTask](nil),
 		suspendBias:    suspendBias,
 		queueAddCh:     make(chan *servingTask, 100),
 		queueBestCh:    make(chan *servingTask),
@@ -214,7 +214,7 @@ func (sq *servingQueue) freezePeers() {
 	}
 	sq.best = nil
 	for sq.queue.Size() > 0 {
-		task := sq.queue.PopItem().(*servingTask)
+		task := sq.queue.PopItem()
 		tasks := peerMap[task.peer]
 		if tasks == nil {
 			bufValue, bufLimit := task.peer.fcClient.BufferStatus()
@@ -251,7 +251,7 @@ func (sq *servingQueue) freezePeers() {
 		}
 	}
 	if sq.queue.Size() > 0 {
-		sq.best = sq.queue.PopItem().(*servingTask)
+		sq.best = sq.queue.PopItem()
 	}
 }
 
@@ -310,7 +310,7 @@ func (sq *servingQueue) queueLoop() {
 				if sq.queue.Size() == 0 {
 					sq.best = nil
 				} else {
-					sq.best, _ = sq.queue.PopItem().(*servingTask)
+					sq.best = sq.queue.PopItem()
 				}
 			case <-sq.quit:
 				return

les/vflux/server/prioritypool.go

@@ -77,8 +77,8 @@ type priorityPool struct {
 	// temporary state if tempState is not empty
 	tempState              []*ppNodeInfo
 	activeCount, activeCap uint64
-	activeQueue            *prque.LazyQueue
+	activeQueue            *prque.LazyQueue[int64, *ppNodeInfo]
-	inactiveQueue          *prque.Prque
+	inactiveQueue          *prque.Prque[int64, *ppNodeInfo]
 }
 
 // ppNodeInfo is the internal node descriptor of priorityPool
@@ -104,7 +104,7 @@ func newPriorityPool(ns *nodestate.NodeStateMachine, setup *serverSetup, clock m
 		setup:           setup,
 		ns:              ns,
 		clock:           clock,
-		inactiveQueue:   prque.New(inactiveSetIndex),
+		inactiveQueue:   prque.New[int64, *ppNodeInfo](inactiveSetIndex),
 		minCap:          minCap,
 		activeBias:      activeBias,
 		capacityStepDiv: capacityStepDiv,
@@ -183,8 +183,7 @@ func (pp *priorityPool) requestCapacity(node *enode.Node, minTarget, maxTarget u
 	}
 	pp.setTempCapacity(c, maxTarget)
 	c.minTarget = minTarget
-	pp.activeQueue.Remove(c.activeIndex)
+	pp.removeFromQueues(c)
-	pp.inactiveQueue.Remove(c.inactiveIndex)
 	pp.activeQueue.Push(c)
 	pp.enforceLimits()
 	updates := pp.finalizeChanges(c.tempCapacity >= minTarget && c.tempCapacity <= maxTarget && c.tempCapacity != c.capacity)
@@ -250,13 +249,13 @@ func (pp *priorityPool) Limits() (uint64, uint64) {
 }
 
 // inactiveSetIndex callback updates ppNodeInfo item index in inactiveQueue
-func inactiveSetIndex(a interface{}, index int) {
+func inactiveSetIndex(a *ppNodeInfo, index int) {
-	a.(*ppNodeInfo).inactiveIndex = index
+	a.inactiveIndex = index
 }
 
 // activeSetIndex callback updates ppNodeInfo item index in activeQueue
-func activeSetIndex(a interface{}, index int) {
+func activeSetIndex(a *ppNodeInfo, index int) {
-	a.(*ppNodeInfo).activeIndex = index
+	a.activeIndex = index
 }
 
 // invertPriority inverts a priority value. The active queue uses inverted priorities
@@ -269,8 +268,7 @@ func invertPriority(p int64) int64 {
 }
 
 // activePriority callback returns actual priority of ppNodeInfo item in activeQueue
-func activePriority(a interface{}) int64 {
+func activePriority(c *ppNodeInfo) int64 {
-	c := a.(*ppNodeInfo)
 	if c.bias == 0 {
 		return invertPriority(c.nodePriority.priority(c.tempCapacity))
 	} else {
@@ -279,8 +277,7 @@ func activePriority(a interface{}) int64 {
 }
 
 // activeMaxPriority callback returns estimated maximum priority of ppNodeInfo item in activeQueue
-func (pp *priorityPool) activeMaxPriority(a interface{}, until mclock.AbsTime) int64 {
+func (pp *priorityPool) activeMaxPriority(c *ppNodeInfo, until mclock.AbsTime) int64 {
-	c := a.(*ppNodeInfo)
 	future := time.Duration(until - pp.clock.Now())
 	if future < 0 {
 		future = 0
@@ -293,6 +290,16 @@ func (pp *priorityPool) inactivePriority(p *ppNodeInfo) int64 {
 	return p.nodePriority.priority(pp.minCap)
 }
 
+// removeFromQueues removes the node from the active/inactive queues
+func (pp *priorityPool) removeFromQueues(c *ppNodeInfo) {
+	if c.activeIndex >= 0 {
+		pp.activeQueue.Remove(c.activeIndex)
+	}
+	if c.inactiveIndex >= 0 {
+		pp.inactiveQueue.Remove(c.inactiveIndex)
+	}
+}
+
 // connectNode is called when a new node has been added to the pool (inactiveFlag set)
 // Note: this function should run inside a NodeStateMachine operation
 func (pp *priorityPool) connectNode(c *ppNodeInfo) {
@@ -320,8 +327,7 @@ func (pp *priorityPool) disconnectNode(c *ppNodeInfo) {
 		return
 	}
 	c.connected = false
-	pp.activeQueue.Remove(c.activeIndex)
+	pp.removeFromQueues(c)
-	pp.inactiveQueue.Remove(c.inactiveIndex)
 
 	var updates []capUpdate
 	if c.capacity != 0 {
@@ -411,11 +417,11 @@ func (pp *priorityPool) enforceLimits() (*ppNodeInfo, int64) {
 		return nil, math.MinInt64
 	}
 	var (
-		c                 *ppNodeInfo
+		lastNode          *ppNodeInfo
 		maxActivePriority int64
 	)
-	pp.activeQueue.MultiPop(func(data interface{}, priority int64) bool {
+	pp.activeQueue.MultiPop(func(c *ppNodeInfo, priority int64) bool {
-		c = data.(*ppNodeInfo)
+		lastNode = c
 		pp.setTempState(c)
 		maxActivePriority = priority
 		if c.tempCapacity == c.minTarget || pp.activeCount > pp.maxCount {
@@ -433,7 +439,7 @@ func (pp *priorityPool) enforceLimits() (*ppNodeInfo, int64) {
 		}
 		return pp.activeCap > pp.maxCap || pp.activeCount > pp.maxCount
 	})
-	return c, invertPriority(maxActivePriority)
+	return lastNode, invertPriority(maxActivePriority)
 }
 
 // finalizeChanges either commits or reverts temporary changes. The necessary capacity
@@ -442,8 +448,7 @@ func (pp *priorityPool) enforceLimits() (*ppNodeInfo, int64) {
 func (pp *priorityPool) finalizeChanges(commit bool) (updates []capUpdate) {
 	for _, c := range pp.tempState {
 		// always remove and push back in order to update biased priority
-		pp.activeQueue.Remove(c.activeIndex)
+		pp.removeFromQueues(c)
-		pp.inactiveQueue.Remove(c.inactiveIndex)
 		oldCapacity := c.capacity
 		if commit {
 			c.capacity = c.tempCapacity
@@ -496,7 +501,7 @@ func (pp *priorityPool) updateFlags(updates []capUpdate) {
 // tryActivate tries to activate inactive nodes if possible
 func (pp *priorityPool) tryActivate(commit bool) []capUpdate {
 	for pp.inactiveQueue.Size() > 0 {
-		c := pp.inactiveQueue.PopItem().(*ppNodeInfo)
+		c := pp.inactiveQueue.PopItem()
 		pp.setTempState(c)
 		pp.setTempBias(c, pp.activeBias)
 		pp.setTempCapacity(c, pp.minCap)
@@ -524,8 +529,7 @@ func (pp *priorityPool) updatePriority(node *enode.Node) {
 		pp.lock.Unlock()
 		return
 	}
-	pp.activeQueue.Remove(c.activeIndex)
+	pp.removeFromQueues(c)
-	pp.inactiveQueue.Remove(c.inactiveIndex)
 	if c.capacity != 0 {
 		pp.activeQueue.Push(c)
 	} else {

trie/sync.go

@@ -160,7 +160,7 @@ type Sync struct {
 	membatch *syncMemBatch                // Memory buffer to avoid frequent database writes
 	nodeReqs map[string]*nodeRequest      // Pending requests pertaining to a trie node path
 	codeReqs map[common.Hash]*codeRequest // Pending requests pertaining to a code hash
-	queue    *prque.Prque                 // Priority queue with the pending requests
+	queue    *prque.Prque[int64, any]     // Priority queue with the pending requests
 	fetches  map[int]int                  // Number of active fetches per trie node depth
 }
 
@@ -172,7 +172,7 @@ func NewSync(root common.Hash, database ethdb.KeyValueReader, callback LeafCallb
 		membatch: newSyncMemBatch(),
 		nodeReqs: make(map[string]*nodeRequest),
 		codeReqs: make(map[common.Hash]*codeRequest),
-		queue:    prque.New(nil),
+		queue:    prque.New[int64, any](nil), // Ugh, can contain both string and hash, whyyy
 		fetches:  make(map[int]int),
 	}
 	ts.AddSubTrie(root, nil, common.Hash{}, nil, callback)