Update queue.go

Author: cassiozareck

modules/queue/queue.go

@@ -2,61 +2,64 @@
 // SPDX-License-Identifier: MIT
 
 // Package queue implements a specialized concurrent queue system for Gitea.
-//
+
 // Terminology:
-//
-//  1. Task:
-//     -	A task can be a simple value, such as an integer, or a more complex structure that has multiple fields and
-//     methods. The aim of a task is to be a unit of work, a set of tasks will be sent to a handler to be processed.
+
+//  1. Item:
+// 	- An item can be a simple value, such as an integer, or a more complex structure that has multiple fields and
+// 	methods. Usually a item serves as a unit of work, sets of items will be sent to a handler to be processed.
+//  - It's represented as a binary slice on the queue
+//	- When an item serve as a unit of work generally it will be referred as a task	
 //
 //  2. Batch:
-//     - A collection of tasks that are grouped together for processing. Each worker receives a batch of tasks.
+// 	- A collection of items that are grouped together for processing. Each worker receives a batch of items.
 //
 //  3. Worker:
-//     - Individual unit of execution designed to process tasks from the queue. It's a goroutine that calls the Handler
-//     - Workers will get new tasks through a channel (WorkerPoolQueue is responsible for the distribution)
-//     - As workers operate in parallel, the default value of max workers is n/2, where n is the number of logical CPUs
+// 	- Individual unit of execution designed to process items from the queue. It's a goroutine that calls the Handler.
+// 	- Workers will get new items through a channel (WorkerPoolQueue is responsible for the distribution).
+// 	- Workers operate in parallel. The default value of max workers is determined by the setting system.
 //
 //  4. Handler (represented by HandlerFuncT type):
-//     - It's the function responsible to process tasks. Each active worker will call this.
-//     - When processing these batches, there might be instances where certain tasks remain unprocessed or "unhandled".
-//     In such scenarios, the Handler ensures these unhandled tasks are returned to the base queue after a brief delay.
-//     This mechanism is particularly beneficial in cases where the processing entity (like a document indexer) is
-//     temporarily unavailable. It ensures that no task is skipped or lost due to transient failures in the processing
-//     mechanism.
+// 	- It's the function responsible for processing items. Each active worker will call it.
+// 	- When processing batches, there might be instances where certain items remain unprocessed or "unhandled".
+// 	In such scenarios, the Handler ensures these unhandled items are returned to the base queue after a brief delay.
+// 	This mechanism is particularly beneficial in cases where the processing entity (like a document indexer) is
+// 	temporarily unavailable. It ensures that no item is skipped or lost due to transient failures in the processing
+// 	mechanism.
 //
 //  5. Base queue:
-//     - Represents the underlying storage mechanism for the queue. There are several implementations:
-//     - Channel: Uses Go's native channel constructs to manage the queue, suitable for in-memory queuing.
-//     - Level, Redis: Especially useful in persistent queues and clusters, where we may have multiple nodes.
-//     - Dummy: This is special, it's not a real queue, it's only used as a no-op queue or a testing queue.
-//     - They all have the same abstraction, the same interface, and they are tested by the same testing code.
+// 	- Represents the underlying storage mechanism for the queue. There are several implementations:
+// 	- Channel: Uses Go's native channel constructs to manage the queue, suitable for in-memory queuing.
+// 	- LevelDB: Especially useful in persistent queues for single instances.
+// 	- Redis: Suitable for clusters, where we may have multiple nodes.
+// 	- Dummy: This is special, it's not a real queue, it's a immediate no-op queue, which is useful for tests.
+// 	- They all have the same abstraction, the same interface, and they are tested by the same testing code.
 //
 // 6. WorkerPoolQueue:
-//   - It's responsible to glue all together, using the "base queue" to provide "worker pool" functionality. He creates
-//     new workers if needed and can flush the queue, running all the tasks synchronously till it finishes.
+//   - It's responsible to glue all together, using the "base queue" to provide "worker pool" functionality. It creates
+// 	new workers if needed and can flush the queue, running all the items synchronously till it finishes.
 //   - Its "Push" function doesn't block forever, it will return an error if the queue is full after the timeout.
 //
 // 7. Manager:
 //   - The purpose of it is to serve as a centralized manager for multiple WorkerPoolQueue instances. Whenever we want
-//     to create a new queue, flush, or get a specific queue, we have to use it.
+// 	to create a new queue, flush, or get a specific queue, we have to use it.
 //
 // A queue can be "simple" or "unique". A unique queue will try to avoid duplicate items.
 // Unique queue's "Has" function can be used to check whether an item is already in the queue,
-// although it's not 100% reliable due to there is no proper transaction support.
+// although it's not 100% reliable due to the lack of proper transaction support.
 // Simple queue's "Has" function always returns "has=false".
 //
 // A WorkerPoolQueue is a generic struct; this means it will work with any type but just for that type.
-// If you want another kind of tasks to run, you would have to call the manager to create a new WorkerPoolQueue for you
-// with a different handler that works with this new type of task. As an example of this:
+// If you want another kind of items to run, you would have to call the manager to create a new WorkerPoolQueue for you
+// with a different handler that works with this new type of item. As an example of this:
 //
-//	func Init() error {
-//		taskQueue = queue.CreateSimpleQueue(graceful.GetManager().ShutdownContext(), "task", handler)
-//		...
-//	}
-//	func handler(items ...*admin_model.Task) []*admin_model.Task { ... }
+//    func Init() error {
+//   	 itemQueue = queue.CreateSimpleQueue(graceful.GetManager().ShutdownContext(), "item", handler)
+//   	 ...
+//    }
+//    func handler(items ...*admin_model.Item) []*admin_model.Item { ... }
 //
-// As you can see, the handler defined the admin_model.Task type for the queue
+// As you can see, the handler defined the admin_model.Item type for the queue
 package queue
 
 import "code.gitea.io/gitea/modules/util"