feat: add data structures from utils (iterator, buffer, sampler, etc)

buffer/bounded_nonblocking_queue_test.go

@@ -0,0 +1,142 @@
+// Copyright (C) 2019-2025, Lux Industries, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+package buffer
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestNewBoundedQueue(t *testing.T) {
+	require := require.New(t)
+
+	// Case: maxSize < 1
+	_, err := NewBoundedQueue[bool](0, nil)
+	require.ErrorIs(err, errInvalidMaxSize)
+
+	// Case: maxSize == 1 and nil onEvict
+	b, err := NewBoundedQueue[bool](1, nil)
+	require.NoError(err)
+
+	// Put 2 elements to make sure we don't panic on evict
+	b.Push(true)
+	b.Push(true)
+}
+
+func TestBoundedQueue(t *testing.T) {
+	require := require.New(t)
+
+	maxSize := 3
+	evicted := []int{}
+	onEvict := func(elt int) {
+		evicted = append(evicted, elt)
+	}
+	b, err := NewBoundedQueue(maxSize, onEvict)
+	require.NoError(err)
+
+	require.Zero(b.Len())
+
+	// Fill the queue
+	for i := 0; i < maxSize; i++ {
+		b.Push(i)
+		require.Equal(i+1, b.Len())
+		got, ok := b.Peek()
+		require.True(ok)
+		require.Zero(got)
+		got, ok = b.Index(i)
+		require.True(ok)
+		require.Equal(i, got)
+		require.Len(b.List(), i+1)
+	}
+	require.Equal([]int{}, evicted)
+	require.Len(b.List(), maxSize)
+	// Queue is [0, 1, 2]
+
+	// Empty the queue
+	for i := 0; i < maxSize; i++ {
+		got, ok := b.Pop()
+		require.True(ok)
+		require.Equal(i, got)
+		require.Equal(maxSize-i-1, b.Len())
+		require.Len(b.List(), maxSize-i-1)
+	}
+
+	// Queue is empty
+
+	_, ok := b.Pop()
+	require.False(ok)
+	_, ok = b.Peek()
+	require.False(ok)
+	_, ok = b.Index(0)
+	require.False(ok)
+	require.Zero(b.Len())
+	require.Empty(b.List())
+
+	// Fill the queue again
+	for i := 0; i < maxSize; i++ {
+		b.Push(i)
+		require.Equal(i+1, b.Len())
+	}
+
+	// Queue is [0, 1, 2]
+
+	// Putting another element should evict the oldest.
+	b.Push(maxSize)
+
+	// Queue is [1, 2, 3]
+
+	require.Equal(maxSize, b.Len())
+	require.Len(b.List(), maxSize)
+	got, ok := b.Peek()
+	require.True(ok)
+	require.Equal(1, got)
+	got, ok = b.Index(0)
+	require.True(ok)
+	require.Equal(1, got)
+	got, ok = b.Index(maxSize - 1)
+	require.True(ok)
+	require.Equal(maxSize, got)
+	require.Equal([]int{0}, evicted)
+
+	// Put 2 more elements
+	b.Push(maxSize + 1)
+	b.Push(maxSize + 2)
+
+	// Queue is [3, 4, 5]
+
+	require.Equal(maxSize, b.Len())
+	require.Equal([]int{0, 1, 2}, evicted)
+	got, ok = b.Peek()
+	require.True(ok)
+	require.Equal(3, got)
+	require.Equal([]int{3, 4, 5}, b.List())
+
+	for i := maxSize; i < 2*maxSize; i++ {
+		got, ok := b.Index(i - maxSize)
+		require.True(ok)
+		require.Equal(i, got)
+	}
+
+	// Empty the queue
+	for i := 0; i < maxSize; i++ {
+		got, ok := b.Pop()
+		require.True(ok)
+		require.Equal(i+3, got)
+		require.Equal(maxSize-i-1, b.Len())
+		require.Len(b.List(), maxSize-i-1)
+	}
+
+	// Queue is empty
+
+	require.Empty(b.List())
+	require.Zero(b.Len())
+	require.Equal([]int{0, 1, 2}, evicted)
+	_, ok = b.Pop()
+	require.False(ok)
+	_, ok = b.Peek()
+	require.False(ok)
+	_, ok = b.Index(0)
+	require.False(ok)
+}