Closer

Closer is a Go package that provides a mechanism for managing the closing of multiple functions in a controlled and concurrency-safe manner. The package allows you to add functions that should be executed upon closing and then close them one by one or all at once.

Key Features

• Add Functions: You can add functions that need to be executed upon closing using the Add method.
• Close All Functions: The Close method allows you to close all added functions simultaneously, executing them in separate goroutines. Note: The Close method does not guarantee the order of execution.
• Step-by-Step Closing: The CloseOne method allows you to close functions one by one in a FIFO (First-In-First-Out) order, which can be useful in scenarios where sequential resource closing is required.
• Concurrency Safety: All operations with functions are synchronized using a mutex, ensuring safety in a multi-threaded environment.
• Error Handling: If errors occur while closing functions, they are collected and returned as a single error message.

Example Usage

package main

import (
	"context"
	"fmt"
	"time"

	"github.com/ilKhr/closer"
)

func main() {
	ctx := context.Background()

	// Create an instance of Closer
	var cl closer.Closer

	// Add functions to be closed
	cl.Add(func(ctx context.Context) error {
		fmt.Println("Closing service 1")
		time.Sleep(5 * time.Second)
		return nil
	})

	cl.Add(func(ctx context.Context) error {
		fmt.Println("Closing service 2")
		time.Sleep(3 * time.Second)
		return fmt.Errorf("error closing service 2")
	})

	// Close all functions
	err := cl.Close(ctx)
	if err != nil {
		fmt.Printf("Error closing services: %v\n", err)
	}
}

Methods

Add(f Func)

Adds the function f to the list of functions that should be closed.

Close(ctx context.Context) error

Closes all added functions simultaneously. If errors occur while closing, they are collected and returned as a single error message.

CloseOne(ctx context.Context) error

Closes one function and updates the index for the next operation. If all functions have already been closed, it returns the ErrAllServicesClosed error.

Size() int

Returns the number of added functions to be closed.

Types

Func func(ctx context.Context) error

The type of function that takes a context and returns an error. This type is used for adding functions to the closing list.

Errors

• ErrAllServicesClosed: Returned if all functions have already been closed, and attempting to close them again is meaningless.

Dependencies

The package uses standard Go libraries such as context, fmt, strings, and sync.

Installation

go get github.com/ilKhr/closer

License

This project is licensed under the MIT License.

Author

Khorishko Ilya

Contributing

Contributions are welcome! Please create an issue or pull request on GitHub.