statistics: add basic analysis job queue (#50126)

ref #50132

pkg/statistics/handle/autoanalyze/priorityqueue/BUILD.bazel

@@ -0,0 +1,20 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "priorityqueue",
+    srcs = [
+        "job.go",
+        "queue.go",
+    ],
+    importpath = "github.com/pingcap/tidb/pkg/statistics/handle/autoanalyze/priorityqueue",
+    visibility = ["//visibility:public"],
+)
+
+go_test(
+    name = "priorityqueue_test",
+    timeout = "short",
+    srcs = ["queue_test.go"],
+    embed = [":priorityqueue"],
+    flaky = True,
+    deps = ["@com_github_stretchr_testify//require"],
+)

pkg/statistics/handle/autoanalyze/priorityqueue/job.go

@@ -0,0 +1,21 @@
+// Copyright 2024 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package priorityqueue
+
+// TableAnalysisJob defines the structure for table analysis job information.
+type TableAnalysisJob struct {
+	// TODO: add more information about the job.
+	Weight float64
+}

pkg/statistics/handle/autoanalyze/priorityqueue/queue.go

@@ -0,0 +1,44 @@
+// Copyright 2024 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package priorityqueue
+
+// An AnalysisQueue implements heap.Interface and holds TableAnalysisJobs.
+type AnalysisQueue []*TableAnalysisJob
+
+// Implement the sort.Interface methods for the priority queue.
+
+func (aq AnalysisQueue) Len() int { return len(aq) }
+func (aq AnalysisQueue) Less(i, j int) bool {
+	// We want Pop to give us the highest, not lowest, priority, so we use greater than here.
+	return aq[i].Weight > aq[j].Weight
+}
+func (aq AnalysisQueue) Swap(i, j int) {
+	aq[i], aq[j] = aq[j], aq[i]
+}
+
+// Push adds an item to the priority queue.
+func (aq *AnalysisQueue) Push(x any) {
+	item := x.(*TableAnalysisJob)
+	*aq = append(*aq, item)
+}
+
+// Pop removes the highest priority item from the queue.
+func (aq *AnalysisQueue) Pop() any {
+	old := *aq
+	n := len(old)
+	item := old[n-1]
+	*aq = old[0 : n-1]
+	return item
+}

pkg/statistics/handle/autoanalyze/priorityqueue/queue_test.go

@@ -0,0 +1,58 @@
+// Copyright 2024 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package priorityqueue
+
+import (
+	"container/heap"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestAnalysisQueue(t *testing.T) {
+	// Test data
+	job1 := &TableAnalysisJob{Weight: 10}
+	job2 := &TableAnalysisJob{Weight: 5}
+	job3 := &TableAnalysisJob{Weight: 15}
+
+	// Create an empty priority queue
+	queue := AnalysisQueue{}
+
+	// Push items into the queue
+	heap.Push(&queue, job1)
+	heap.Push(&queue, job2)
+	heap.Push(&queue, job3)
+
+	// Test Len()
+	require.Equal(t, 3, queue.Len(), "Length of the queue should be 3")
+
+	// Test Less()
+	require.True(t, queue.Less(0, 1), "Item at index 0 should have higher priority than item at index 1")
+
+	// Test Swap()
+	queue.Swap(0, 2)
+	require.NotEqual(t, float64(15), queue[0].Weight, "Item at index 0 should not have weight 15 after swap")
+}
+
+func TestPushPop(t *testing.T) {
+	// Test Push and Pop operations together
+	queue := AnalysisQueue{}
+	heap.Push(&queue, &TableAnalysisJob{Weight: 10})
+	heap.Push(&queue, &TableAnalysisJob{Weight: 5})
+
+	poppedItem := heap.Pop(&queue).(*TableAnalysisJob)
+	require.Equal(t, float64(10), poppedItem.Weight, "Popped item should have weight 10")
+	require.Equal(t, 1, queue.Len(), "After Pop, length of the queue should be 1")
+}