.github/dependabot.yml

@@ -1,7 +1,7 @@
 # To get started with Dependabot version updates, you'll need to specify which
 # package ecosystems to update and where the package manifests are located.
 # Please see the documentation for all configuration options:
-# https://docs.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
+# https://help.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
 
 version: 2
 updates:
@@ -9,7 +9,3 @@ updates:
     directory: "/" # Location of package manifests
     schedule:
       interval: "daily"
-  - package-ecosystem: "github-actions" # See documentation for possible values
-    directory: "/" # Location of package manifests
-    schedule:
-      interval: "daily"

.github/workflows/codeql-analysis.yml

@@ -38,11 +38,11 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v4
+      uses: actions/checkout@v2
 
     # Initializes the CodeQL tools for scanning.
     - name: Initialize CodeQL
-      uses: github/codeql-action/init@v2
+      uses: github/codeql-action/init@v1
       with:
         languages: ${{ matrix.language }}
         # If you wish to specify custom queries, you can do so here or in a config file.
@@ -53,7 +53,7 @@ jobs:
     # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
     # If this step fails, then you should remove it and run the build manually (see below)
     - name: Autobuild
-      uses: github/codeql-action/autobuild@v2
+      uses: github/codeql-action/autobuild@v1
 
     # ℹ️ Command-line programs to run using the OS shell.
     # 📚 https://git.io/JvXDl
@@ -67,4 +67,4 @@ jobs:
     #   make release
 
     - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@v2
+      uses: github/codeql-action/analyze@v1

.github/workflows/go.yml

@@ -6,12 +6,12 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v2
         with:
           fetch-depth: 2
-      - uses: actions/setup-go@v4
+      - uses: actions/setup-go@v2
         with:
-          go-version: '1.21'
+          go-version: '1.17'
       - name: Run coverage
         run: go test -v -race -coverprofile=coverage.txt -covermode=atomic ./...
       - name: Upload coverage to Codecov

queue/errors.go

@@ -0,0 +1,5 @@
+package queue
+
+import "errors"
+
+var ErrQueueFull = errors.New("bounded queue is full")

queue/queue.go

@@ -0,0 +1,122 @@
+package queue
+
+import (
+	"fmt"
+	"sync"
+	"sync/atomic"
+
+	"git.tcp.direct/kayos/common/list"
+	"golang.org/x/exp/constraints"
+)
+
+type Item[P constraints.Ordered, V any] struct {
+	value    *V
+	priority P
+	index    int
+}
+
+func NewItem[P constraints.Ordered, V any](v *V, p P) *Item[P, V] {
+	return &Item[P, V]{
+		value:    v,
+		priority: p,
+		index:    0,
+	}
+}
+
+func (i *Item[P, V]) Less(j any) bool {
+	return i.priority < j.(Item[P, V]).priority
+}
+
+func (i *Item[P, V]) Value() *V {
+	return i.value
+}
+
+func (i *Item[P, V]) Priority() P {
+	return i.priority
+}
+
+func (i *Item[P, V]) Set(v *V) {
+	i.value = v
+}
+
+func (i *Item[P, V]) SetPriority(p P) {
+	i.priority = p
+}
+
+type boundedQueue[P constraints.Ordered, V any] struct {
+	items []*Item[P, V]
+	qcap  int64
+	qlen  *atomic.Int64
+	mu    *sync.RWMutex
+	errs  *list.LockingList
+}
+
+type BoundedQueue[P constraints.Ordered, V any] struct {
+	// making sure container/heap can access boundedQueue without the normal API being exposed to the user
+	inner *boundedQueue[P, V]
+}
+
+func NewBoundedQueue[P constraints.Ordered, V any](cap int64) *BoundedQueue[P, V] {
+	bq := &BoundedQueue[P, V]{}
+	bq.inner = &boundedQueue[P, V]{
+		items: make([]*Item[P, V], 0, cap),
+		qcap:  cap,
+		qlen:  &atomic.Int64{},
+		mu:    &sync.RWMutex{},
+		errs:  list.New(),
+	}
+	bq.inner.qlen.Store(0)
+	return bq
+}
+
+func (b *boundedQueue[P, V]) err(err error) {
+	b.errs.PushBack(err)
+}
+
+func (b *BoundedQueue[P, V]) Err() error {
+	errLen := b.inner.errs.Len()
+	switch errLen {
+	case 0:
+		return nil
+	case 1:
+		return b.inner.errs.Front().Value().(error)
+	default:
+		return fmt.Errorf("%w | (%d more errors in queue)", b.inner.errs.Front().Value().(error), errLen-1)
+	}
+}
+
+func (b *BoundedQueue[P, V]) Len() int {
+	return int(b.inner.qlen.Load())
+}
+
+func (b *boundedQueue[P, V]) Less(i, j int) bool {
+	b.mu.RLock()
+	less := b.items[P, V][i].priority < b.items[P, V][j].priority
+	b.mu.RUnlock()
+	return less
+}
+
+func (b *boundedQueue[P, V]) Swap(i, j int) {
+	b.mu.Lock()
+	b.items[P, V][i], b.items[P, V][j] = b.items[P, V][j], b.items[P, V][i]
+	b.items[P, V][i].index = i
+	b.items[P, V][j].index = j
+	b.mu.Unlock()
+}
+
+func (b *boundedQueue[P, V]) Push(x any) {
+	if b.qlen.Load() >= b.qcap {
+		b.err(fmt.Errorf("%w: %v dropped", ErrQueueFull, x))
+		return
+	}
+	defer b.qlen.Add(1)
+	b.mu.Lock()
+	b.items[P, V] = append(b.items[P, V], x.(*Item[P, V]))
+	b.qlen.Add(1)
+	b.mu.Unlock()
+}
+
+func (b *boundedQueue[P, V]) Pop() any {
+	// todo
+	return nil
+}