Update readme

README.md

@@ -15,7 +15,7 @@ Highlevel overview of how Asynq works:
 
 - Client puts task on a queue
 - Server pulls task off queues and starts a worker goroutine for each task
-- Workers process tasks concurrently
+- Tasks are processed concurrently by multiple workers
 
 Task queues are used as a mechanism to distribute work across multiple machines.  
 A system can consist of multiple worker servers and brokers, giving way to high availability and horizontal scaling.
@@ -24,24 +24,24 @@ A system can consist of multiple worker servers and brokers, giving way to high
 
 ## Stability and Compatibility
 
-**Important Note**: Current major version is zero (v0.x.x) to accomodate rapid development and fast iteration while getting early feedback from users. The public API could change without a major version update before v1.0.0 release.
+**Important Note**: Current major version is zero (v0.x.x) to accomodate rapid development and fast iteration while getting early feedback from users (Feedback on APIs are appreciated!). The public API could change without a major version update before v1.0.0 release.
 
 **Status**: The library is currently undergoing heavy development with frequent, breaking API changes.
 
 ## Features
 
-- Guaranteed at least one execution of a task
+- Guaranteed [at least one execution](https://www.cloudcomputingpatterns.org/at_least_once_delivery/) of a task
 - Scheduling of tasks
 - Durability since tasks are written to Redis
-- Retries of failed tasks
-- Concurrency management via configuration
-- Weighted priority queues
-- Strict priority queues
+- [Retries](https://github.com/hibiken/asynq/wiki/Task-Retry) of failed tasks
+- [Weighted priority queues](https://github.com/hibiken/asynq/wiki/Priority-Queues#weighted-priority-queues)
+- [Strict priority queues](https://github.com/hibiken/asynq/wiki/Priority-Queues#strict-priority-queues)
 - Low latency to add a task since writes are fast in Redis
-- De-duplication of tasks using unique option
+- De-duplication of tasks using [unique option](https://github.com/hibiken/asynq/wiki/Unique-Tasks)
 - Allow timeout and deadline per task
 - Flexible handler interface with support for middlewares
-- CLI to inspect and remote-control queues and tasks
+- [Support Redis Sentinels](https://github.com/hibiken/asynq/wiki/Automatic-Failover) for HA
+- [CLI](#command-line-tool) to inspect and remote-control queues and tasks
 
 ## Quickstart
 
@@ -62,13 +62,15 @@ import (
     "github.com/hibiken/asynq"
 )
 
-// A list of background task types.
+// A list of task types.
 const (
     EmailDelivery   = "email:deliver"
     ImageProcessing = "image:process"
 )
 
+//--------------------------------------------
 // Write function NewXXXTask to create a task.
+//--------------------------------------------
 
 func NewEmailDeliveryTask(userID int, tmplID string) *asynq.Task {
     payload := map[string]interface{}{"user_id": userID, "template_id": tmplID}
@@ -80,8 +82,13 @@ func NewImageProcessingTask(src, dst string) *asynq.Task {
     return asynq.NewTask(ImageProcessing, payload)
 }
 
+//-------------------------------------------------------------
 // Write function HandleXXXTask to handle the given task.
 // NOTE: It satisfies the asynq.HandlerFunc interface.
+// 
+// Handler doesn't need to be a function. You can define a type 
+// that satisfies asynq.Handler interface. See example below.
+//-------------------------------------------------------------
 
 func HandleEmailDeliveryTask(ctx context.Context, t *asynq.Task) error {
     userID, err := t.Payload.GetInt("user_id")
@@ -97,7 +104,12 @@ func HandleEmailDeliveryTask(ctx context.Context, t *asynq.Task) error {
     return nil
 }
 
-func HandleImageProcessingTask(ctx context.Context, t *asynq.Task) error {
+type ImageProcesser struct {
+    // ... fields for struct
+}
+
+// ImageProcessor implements asynq.Handler.
+func (p *ImageProcessor) ProcessTask(ctx context.Context, t *asynq.Task) error {
     src, err := t.Payload.GetString("src")
     if err != nil {
         return err
@@ -110,6 +122,10 @@ func HandleImageProcessingTask(ctx context.Context, t *asynq.Task) error {
     // Image processing logic ...
     return nil
 }
+
+func NewImageProcessor() *ImageProcessor {
+    // ... return an instance
+}
 ```
 
 In your web application code, import the above package and use [`Client`](https://pkg.go.dev/github.com/hibiken/asynq?tab=doc#Client) to put tasks on the queue.  
@@ -132,7 +148,10 @@ func main() {
     r := asynq.RedisClientOpt{Addr: redisAddr}
     c := asynq.NewClient(r)
 
+    // ----------------------------------------------------
     // Example 1: Enqueue task to be processed immediately.
+    //            Use (*Client).Enqueue method.
+    // ---------------------------------------------------- 
 
     t := tasks.NewEmailDeliveryTask(42, "some:template:id")
     err := c.Enqueue(t)
@@ -141,7 +160,10 @@ func main() {
     }
 
 
+    // ----------------------------------------------------------
     // Example 2: Schedule task to be processed in the future.
+    //            Use (*Client).EnqueueIn or (*Client).EnqueueAt.
+    // ----------------------------------------------------------
 
     t = tasks.NewEmailDeliveryTask(42, "other:template:id")
     err = c.EnqueueIn(24*time.Hour, t)
@@ -150,8 +172,10 @@ func main() {
     }
 
 
+    // --------------------------------------------------------------------------
     // Example 3: Pass options to tune task processing behavior.
-    // Options include MaxRetry, Queue, Timeout, Deadline, Unique etc.
+    //            Options include MaxRetry, Queue, Timeout, Deadline, Unique etc.
+    // --------------------------------------------------------------------------
 
     t = tasks.NewImageProcessingTask("some/blobstore/url", "other/blobstore/url")
     err = c.Enqueue(t, asynq.MaxRetry(10), asynq.Queue("critical"), asynq.Timeout(time.Minute))
@@ -161,7 +185,7 @@ func main() {
 }
 ```
 
-Next, create a work server binary to process these tasks in the background.  
+Next, create a worker server to process these tasks in the background.  
 To start the background workers, use [`Server`](https://pkg.go.dev/github.com/hibiken/asynq?tab=doc#Server) and provide your [`Handler`](https://pkg.go.dev/github.com/hibiken/asynq?tab=doc#Handler) to process the tasks.
 
 You can optionally use [`ServeMux`](https://pkg.go.dev/github.com/hibiken/asynq?tab=doc#ServeMux) to create a handler, just as you would with [`"net/http"`](https://golang.org/pkg/net/http/) Handler.
@@ -194,7 +218,7 @@ func main() {
     // mux maps a type to a handler
     mux := asynq.NewServeMux()
     mux.HandleFunc(tasks.EmailDelivery, tasks.HandleEmailDeliveryTask)
-    mux.HandleFunc(tasks.ImageProcessing, tasks.HandleImageProcessingTask)
+    mux.Handle(tasks.ImageProcessing, tasks.NewImageProcessor())
     // ...register other handlers...
 
     if err := srv.Run(mux); err != nil {