refactor code and update readme

Author: amitiwary999

README.md

@@ -1,6 +1,5 @@
 # TaskScheduler
-
-This is use to complete task(function) in parllel to complete task fast. Each task consist of two things function that need to perform and metaId that use to fetch meta from the database using the metaId. Meta is use in the function to perform task. Each task(function) may or may not need parameters. 
+This can use to peform tasks, with option to retry if failed and also peform task after some delay, in parallel to complete task quickly. Each task consist of two things function that need to perform and metaId that use to fetch meta from the database using the metaId. Meta is use in the function to perform task. Each task(function) may or may not need parameters. 
 
 Use go get github.com/amitiwary999/task-scheduler to fetch this module in your code.
 
@@ -9,8 +8,23 @@ import this library and then init the task scheduler
 ```
 import ("github.com/amitiwary999/task-scheduler/scheduler")
 
-tsk := scheduler.NewTaskScheduler(doneChannel, postgresUrl, poolLimit, workerCount, taskQueueLimit)
-go tsk.StartScheduler()
+tconf := &scheduler.TaskConfig{
+    MaxTaskWorker:     10,
+    TaskQueueSize:     10000,
+    Done:              done,
+    RetryTimeDuration: time.Duration(5 * time.Second),
+    FuncGenerator:     generateFunc,
+}
+tsk := scheduler.NewTaskScheduler(tconf)
+/**
+storage use to save the task so that we can fetch fail task later to retry again. Scheduler need StorageClient interface so that it can perform the storage operation. So before InitScheduler call make sure to get a StorageClient interface. We provide the function to create postgres db client. Will add support for the other storage later.
+*/
+dbClient, err := storage.NewPostgresClient(os.Getenv("POSTGRES_URL"), int16(poolLimit), "jobdetail")
+tsk.InitScheduler(dbClient)
+
+/** 
+After init scheduler successfully, Task can be submit. Each task has Meta of task and TaskFn function to perform the task.
+*/
 meta := model.TaskMeta{
 	MetaId: id,
     Delay: intValue(after how much delay task need to perform, optional)

cmd/main.go

@@ -11,7 +11,7 @@ import (
 
 	model "github.com/amitiwary999/task-scheduler/model"
 	scheduler "github.com/amitiwary999/task-scheduler/scheduler"
-
+	storage "github.com/amitiwary999/task-scheduler/storage"
 	"github.com/joho/godotenv"
 )
 
@@ -40,17 +40,14 @@ func main() {
 		gracefulShutdown := make(chan os.Signal, 1)
 		signal.Notify(gracefulShutdown, syscall.SIGINT, syscall.SIGTERM)
 		tconf := &scheduler.TaskConfig{
-			PostgUrl:          os.Getenv("POSTGRES_URL"),
-			PoolLimit:         int16(poolLimit),
 			MaxTaskWorker:     10,
 			TaskQueueSize:     10000,
-			JobTableName:      "jobdetail",
 			Done:              done,
 			RetryTimeDuration: time.Duration(5 * time.Second),
 			FuncGenerator:     generateFunc,
 		}
 		tsk := scheduler.NewTaskScheduler(tconf)
-		postgClient, err := tsk.InitStorage()
+		postgClient, err := storage.NewPostgresClient(os.Getenv("POSTGRES_URL"), int16(poolLimit), "jobdetail")
 		if err != nil {
 			return
 		}

cmd/main_test.go

@@ -4,8 +4,6 @@ import (
 	"errors"
 	"fmt"
 	"math/rand"
-	"os"
-	"strconv"
 	"sync"
 	"testing"
 	"time"
@@ -60,44 +58,38 @@ func TestTaskScheduler(t *testing.T) {
 	if err != nil {
 		t.Errorf("error load env %v\n", err)
 	}
-	poolLimit, err := strconv.Atoi(os.Getenv("POSTGRES_POOL_LIMIT"))
+
+	done := make(chan int)
+	tconf := &scheduler.TaskConfig{
+		MaxTaskWorker:     10,
+		TaskQueueSize:     10000,
+		Done:              done,
+		RetryTimeDuration: time.Duration(3 * time.Second),
+		FuncGenerator:     testGenerateFunc,
+	}
+	tsk := scheduler.NewTaskScheduler(tconf)
+	postgClient := dbStruct{}
+	tsk.InitScheduler(postgClient)
 	if err != nil {
-		t.Errorf("error in the string conversion pool limit %v", err)
-	} else {
-		done := make(chan int)
-		tconf := &scheduler.TaskConfig{
-			PostgUrl:          os.Getenv("POSTGRES_URL"),
-			PoolLimit:         int16(poolLimit),
-			MaxTaskWorker:     10,
-			TaskQueueSize:     10000,
-			JobTableName:      "jobdetail",
-			Done:              done,
-			RetryTimeDuration: time.Duration(3 * time.Second),
-			FuncGenerator:     testGenerateFunc,
+		return
+	}
+	for i := 0; i < 10; i++ {
+		id := fmt.Sprintf("task_%v", i)
+		meta := &model.TaskMeta{
+			MetaId: id,
 		}
-		tsk := scheduler.NewTaskScheduler(tconf)
-		postgClient := dbStruct{}
-		tsk.InitScheduler(postgClient)
-		if err != nil {
-			return
+		if id == "task_6" {
+			meta.Retry = 5
 		}
-		for i := 0; i < 10; i++ {
-			id := fmt.Sprintf("task_%v", i)
-			meta := &model.TaskMeta{
-				MetaId: id,
-			}
-			if id == "task_6" {
-				meta.Retry = 5
-			}
-			mdlTsk := model.Task{
-				Meta: meta,
-			}
-			err := tsk.AddNewTask(mdlTsk)
-			if err == nil {
-				wg.Add(1)
-			}
+		mdlTsk := model.Task{
+			Meta: meta,
+		}
+		err := tsk.AddNewTask(mdlTsk)
+		if err == nil {
+			wg.Add(1)
 		}
 	}
+
 	wg.Wait()
 	if successC == 9 && failC == 1 {
 		t.Log("successfully completed the tasks")

manager/task-manager.go

@@ -10,17 +10,17 @@ import (
 )
 
 type TaskManager struct {
-	postgClient       util.PostgClient
+	storageClient     util.StorageClient
 	taskActor         *TaskActor
 	done              chan int
 	priorityQueue     PriorityQueue
 	retryTimeDuration time.Duration
 	funcGenerator     func() func(*model.TaskMeta) error
 }
 
-func InitManager(postgClient util.PostgClient, taskActor *TaskActor, retryTime time.Duration, funcGenerator func() func(*model.TaskMeta) error, done chan int) *TaskManager {
+func InitManager(storageClient util.StorageClient, taskActor *TaskActor, retryTime time.Duration, funcGenerator func() func(*model.TaskMeta) error, done chan int) *TaskManager {
 	return &TaskManager{
-		postgClient:       postgClient,
+		storageClient:     storageClient,
 		taskActor:         taskActor,
 		funcGenerator:     funcGenerator,
 		retryTimeDuration: retryTime,
@@ -40,7 +40,7 @@ func (tm *TaskManager) AddNewTask(task model.Task) error {
 	if task.Meta.Delay > 0 {
 		task.Meta.ExecutionTime = time.Now().Unix() + int64(task.Meta.Delay)*60
 	}
-	id, err := tm.postgClient.SaveTask(task.Meta)
+	id, err := tm.storageClient.SaveTask(task.Meta)
 	if err != nil {
 		fmt.Printf("failed to save the task %v\n", err)
 		return err
@@ -70,7 +70,7 @@ func (tm *TaskManager) assignTask(idTask string, meta *model.TaskMeta) {
 				taskStatus = util.JOB_DETAIL_STATUS_FAILED
 			}
 		}
-		tm.postgClient.UpdateTaskStatus(idTask, taskStatus, *meta)
+		tm.storageClient.UpdateTaskStatus(idTask, taskStatus, *meta)
 	}
 	tsk := model.ActorTask{
 		Meta:   meta,
@@ -108,7 +108,7 @@ func (tm *TaskManager) retryFailedTask() {
 			ticker.Stop()
 			return
 		case <-ticker.C:
-			tsks, err := tm.postgClient.GetFailTask()
+			tsks, err := tm.storageClient.GetFailTask()
 			if err == nil {
 				for _, tsk := range tsks {
 					go tm.assignTask(tsk.Id, tsk.Meta)
@@ -121,7 +121,7 @@ func (tm *TaskManager) retryFailedTask() {
 }
 
 func (tm *TaskManager) loadPendingTask() {
-	tsks, err := tm.postgClient.GetPendingTask()
+	tsks, err := tm.storageClient.GetPendingTask()
 	if err == nil {
 		for _, tsk := range tsks {
 			go tm.assignTask(tsk.Id, tsk.Meta)

scheduler/TaskSchedulerConfig.go

@@ -1,19 +1,14 @@
 package scheduler
 
 import (
-	"fmt"
 	"time"
 
 	manager "github.com/amitiwary999/task-scheduler/manager"
 	model "github.com/amitiwary999/task-scheduler/model"
-	storage "github.com/amitiwary999/task-scheduler/storage"
 	"github.com/amitiwary999/task-scheduler/util"
 )
 
 type TaskConfig struct {
-	PostgUrl          string
-	PoolLimit         int16
-	JobTableName      string
 	MaxTaskWorker     uint16
 	TaskQueueSize     uint16
 	RetryTimeDuration time.Duration
@@ -22,11 +17,8 @@ type TaskConfig struct {
 }
 
 type TaskScheduler struct {
-	postgUrl          string
-	poolLimit         int16
 	maxTaskWorker     uint16
 	taskQueueSize     uint16
-	jobTableName      string
 	retryTimeDuration time.Duration
 	funcGenerator     func() func(*model.TaskMeta) error
 	done              chan int
@@ -36,33 +28,16 @@ type TaskScheduler struct {
 func NewTaskScheduler(tconf *TaskConfig) *TaskScheduler {
 	return &TaskScheduler{
 		done:              tconf.Done,
-		postgUrl:          tconf.PostgUrl,
-		poolLimit:         tconf.PoolLimit,
 		maxTaskWorker:     tconf.MaxTaskWorker,
 		taskQueueSize:     tconf.TaskQueueSize,
-		jobTableName:      tconf.JobTableName,
 		funcGenerator:     tconf.FuncGenerator,
 		retryTimeDuration: tconf.RetryTimeDuration,
 	}
 }
 
-func (t *TaskScheduler) InitStorage() (util.PostgClient, error) {
-	postgClient, error := storage.NewPostgresClient(t.postgUrl, t.poolLimit, t.jobTableName)
-	if error != nil {
-		fmt.Printf("postgres cient failed %v\n", error)
-		return nil, error
-	}
-	err := postgClient.CreateJobTable()
-	if err != nil {
-		fmt.Printf("failed to create the table to save job details %v \n", err)
-		return nil, err
-	}
-	return postgClient, nil
-}
-
-func (t *TaskScheduler) InitScheduler(postgClient util.PostgClient) {
+func (t *TaskScheduler) InitScheduler(storageClient util.StorageClient) {
 	ta := manager.NewTaskActor(t.maxTaskWorker, t.done, t.taskQueueSize)
-	taskM := manager.InitManager(postgClient, ta, t.retryTimeDuration, t.funcGenerator, t.done)
+	taskM := manager.InitManager(storageClient, ta, t.retryTimeDuration, t.funcGenerator, t.done)
 	t.taskM = taskM
 	taskM.StartManager()
 }

util/type.go

@@ -23,7 +23,7 @@ type SupabaseClient interface {
 	GetPendingTask() ([]byte, error)
 }
 
-type PostgClient interface {
+type StorageClient interface {
 	SaveTask(meta *model.TaskMeta) (string, error)
 	UpdateTaskStatus(id, status string, meta model.TaskMeta) error
 	GetPendingTask() ([]model.PendingTask, error)