planner: encapsulate task dir and move test related code to test file (#52083)

close #51664

Author: AilinKid

pkg/planner/memo/BUILD.bazel

@@ -8,8 +8,6 @@ go_library(
         "group_expr.go",
         "implementation.go",
         "pattern.go",
-        "task.go",
-        "task_scheduler.go",
     ],
     importpath = "github.com/pingcap/tidb/pkg/planner/memo",
     visibility = ["//visibility:public"],
@@ -29,12 +27,10 @@ go_test(
         "group_test.go",
         "main_test.go",
         "pattern_test.go",
-        "task_scheduler_test.go",
-        "task_test.go",
     ],
     embed = [":memo"],
     flaky = True,
-    shard_count = 25,
+    shard_count = 22,
     deps = [
         "//pkg/domain",
         "//pkg/expression",

pkg/planner/task/BUILD.bazel

@@ -0,0 +1,24 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "task",
+    srcs = [
+        "task.go",
+        "task_scheduler.go",
+    ],
+    importpath = "github.com/pingcap/tidb/pkg/planner/task",
+    visibility = ["//visibility:public"],
+)
+
+go_test(
+    name = "task_test",
+    timeout = "short",
+    srcs = [
+        "task_scheduler_test.go",
+        "task_test.go",
+    ],
+    embed = [":task"],
+    flaky = True,
+    shard_count = 3,
+    deps = ["@com_github_stretchr_testify//require"],
+)

pkg/planner/memo/task.go renamed to pkg/planner/task/task.go

@@ -12,14 +12,15 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package memo
+package task
 
 import (
 	"strings"
 	"sync"
 )
 
-// Task is an interface defined for all type of optimizing work: exploring, implementing, deriving-stats, join-reordering and so on.
+// Task is an interface defined for all type of optimizing work: exploring, implementing,
+// deriving-stats, join-reordering and so on.
 type Task interface {
 	// task self executing logic
 	execute() error
@@ -35,8 +36,8 @@ type Stack interface {
 	Destroy()
 }
 
-// TaskStackPool is initialized for memory saving by reusing taskStack.
-var TaskStackPool = sync.Pool{
+// StackTaskPool is initialized for memory saving by reusing taskStack.
+var StackTaskPool = sync.Pool{
 	New: func() any {
 		return newTaskStack()
 	},
@@ -57,7 +58,7 @@ func newTaskStack() *taskStack {
 func (ts *taskStack) Destroy() {
 	// when a taskStack itself is useless, we can destroy itself actively.
 	clear(ts.tasks)
-	TaskStackPool.Put(ts)
+	StackTaskPool.Put(ts)
 }
 
 // Desc is used to desc the detail info about current stack state.
@@ -102,39 +103,3 @@ func newTaskStackWithCap(c int) *taskStack {
 		tasks: make([]Task, 0, c),
 	}
 }
-
-// TaskStack2 is used to store the optimizing tasks created before or during the optimizing process.
-type taskStack2 struct {
-	tasks []*Task
-}
-
-func newTaskStack2WithCap(c int) *taskStack2 {
-	return &taskStack2{
-		tasks: make([]*Task, 0, c),
-	}
-}
-
-// Push indicates to push one task into the stack.
-func (ts *taskStack2) Push(one Task) {
-	ts.tasks = append(ts.tasks, &one)
-}
-
-// Len indicates the length of current stack.
-func (ts *taskStack2) Len() int {
-	return len(ts.tasks)
-}
-
-// Empty indicates whether taskStack is empty.
-func (ts *taskStack2) Empty() bool {
-	return ts.Len() == 0
-}
-
-// Pop indicates to pop one task out of the stack.
-func (ts *taskStack2) Pop() Task {
-	if !ts.Empty() {
-		tmp := ts.tasks[len(ts.tasks)-1]
-		ts.tasks = ts.tasks[:len(ts.tasks)-1]
-		return *tmp
-	}
-	return nil
-}

pkg/planner/memo/task_scheduler.go renamed to pkg/planner/task/task_scheduler.go

@@ -12,19 +12,19 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package memo
+package task
 
-var _ TaskScheduler = &SimpleTaskScheduler{}
+var _ Scheduler = &SimpleTaskScheduler{}
 
-// TaskScheduler is a scheduling interface defined for serializing(single thread)/concurrent(multi thread) running.
-type TaskScheduler interface {
+// Scheduler is a scheduling interface defined for serializing(single thread)/concurrent(multi thread) running.
+type Scheduler interface {
 	ExecuteTasks()
 }
 
 // SimpleTaskScheduler is defined for serializing scheduling of memo tasks.
 type SimpleTaskScheduler struct {
 	Err          error
-	SchedulerCtx TaskSchedulerContext
+	SchedulerCtx SchedulerContext
 }
 
 // ExecuteTasks implements the interface of TaskScheduler.
@@ -46,8 +46,8 @@ func (s *SimpleTaskScheduler) ExecuteTasks() {
 	}
 }
 
-// TaskSchedulerContext is defined for scheduling logic calling, also facilitate interface-oriented coding and testing.
-type TaskSchedulerContext interface {
+// SchedulerContext is defined for scheduling logic calling, also facilitate interface-oriented coding and testing.
+type SchedulerContext interface {
 	// we exported the Stack interface here rather than the basic stack implementation.
 	getStack() Stack
 	// we exported the only one push action to user, Task is an interface definition.

pkg/planner/memo/task_scheduler_test.go renamed to pkg/planner/task/task_scheduler_test.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package memo
+package task
 
 import (
 	"errors"
@@ -63,7 +63,7 @@ func TestSimpleTaskScheduler(t *testing.T) {
 	testScheduler.SchedulerCtx.pushTask(&TestTaskImpl2{a: 2})
 	testScheduler.SchedulerCtx.pushTask(&TestTaskImpl2{a: 3})
 
-	var testTaskScheduler TaskScheduler = testScheduler
+	var testTaskScheduler Scheduler = testScheduler
 	testTaskScheduler.ExecuteTasks()
 	require.NotNil(t, testScheduler.Err)
 	require.Equal(t, testScheduler.Err.Error(), "mock error at task id = 2")

pkg/planner/memo/task_test.go renamed to pkg/planner/task/task_test.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package memo
+package task
 
 import (
 	"strconv"
@@ -50,7 +50,7 @@ func TestTaskStack(t *testing.T) {
 }
 
 func TestTaskFunctionality(t *testing.T) {
-	taskTaskPool := TaskStackPool.Get()
+	taskTaskPool := StackTaskPool.Get()
 	require.Equal(t, len(taskTaskPool.(*taskStack).tasks), 0)
 	require.Equal(t, cap(taskTaskPool.(*taskStack).tasks), 4)
 	ts := taskTaskPool.(*taskStack)
@@ -69,10 +69,10 @@ func TestTaskFunctionality(t *testing.T) {
 	ts.Push(&TestTaskImpl{a: 5})
 	ts.Push(&TestTaskImpl{a: 6})
 	// no clean, put it back
-	TaskStackPool.Put(taskTaskPool)
+	StackTaskPool.Put(taskTaskPool)
 
 	// require again.
-	ts = TaskStackPool.Get().(*taskStack)
+	ts = StackTaskPool.Get().(*taskStack)
 	require.Equal(t, len(ts.tasks), 4)
 	require.Equal(t, cap(ts.tasks), 4)
 	// clean the stack
@@ -89,11 +89,47 @@ func TestTaskFunctionality(t *testing.T) {
 
 	// self destroy.
 	ts.Destroy()
-	ts = TaskStackPool.Get().(*taskStack)
+	ts = StackTaskPool.Get().(*taskStack)
 	require.Equal(t, len(ts.tasks), 0)
 	require.Equal(t, cap(ts.tasks), 4)
 }
 
+// TaskStack2 is used to store the optimizing tasks created before or during the optimizing process.
+type taskStackForBench struct {
+	tasks []*Task
+}
+
+func newTaskStackForBenchWithCap(c int) *taskStackForBench {
+	return &taskStackForBench{
+		tasks: make([]*Task, 0, c),
+	}
+}
+
+// Push indicates to push one task into the stack.
+func (ts *taskStackForBench) Push(one Task) {
+	ts.tasks = append(ts.tasks, &one)
+}
+
+// Len indicates the length of current stack.
+func (ts *taskStackForBench) Len() int {
+	return len(ts.tasks)
+}
+
+// Empty indicates whether taskStack is empty.
+func (ts *taskStackForBench) Empty() bool {
+	return ts.Len() == 0
+}
+
+// Pop indicates to pop one task out of the stack.
+func (ts *taskStackForBench) Pop() Task {
+	if !ts.Empty() {
+		tmp := ts.tasks[len(ts.tasks)-1]
+		ts.tasks = ts.tasks[:len(ts.tasks)-1]
+		return *tmp
+	}
+	return nil
+}
+
 // Benchmark result explanation:
 // On the right side of the function name, you have four values, 43803,27569 ns/op,24000 B/op and 2000 allocs/op
 // The former indicates the total number of times the loop was executed, while the latter is the average amount
@@ -104,7 +140,7 @@ func TestTaskFunctionality(t *testing.T) {
 // BenchmarkTestStack2Pointer-8   	   42889	     27017 ns/op	   24000 B/op	    2000 allocs/op
 // BenchmarkTestStack2Pointer-8   	   43009	     27524 ns/op	   24000 B/op	    2000 allocs/op
 func BenchmarkTestStack2Pointer(b *testing.B) {
-	stack := newTaskStack2WithCap(1000)
+	stack := newTaskStackForBenchWithCap(1000)
 	fill := func() {
 		for idx := int64(0); idx < 1000; idx++ {
 			stack.Push(&TestTaskImpl{a: idx})