Shutdown

The Shutdown provides a structured approach to managing and safely closing resources in a Go application. It offers a variety of strategies to handle different ordering preferences for closing resources such as FIFO (First-In, First-Out), LIFO (Last-In, First-Out), and group-based closings.

Features

• Concurrency Safe: All operations are made concurrency safe using mutex locks.
• Context Support: Allows you to close resources with context support. This is useful for timeouts or external cancellation.
• Error Aggregation: Combines errors from multiple closers into a single error using the go.uber.org/multierr library.

Components

Closer

An alias for io.Closer interface which requires a Close method.

FIFO (First-In, First-Out)

Fifo struct manages a queue of resources to be closed in the order they were added.

LIFO (Last-In, First-Out)

Lifo struct manages a stack of resources, ensuring they are closed in the reverse order they were added.

Group

Group struct manages a collection of resources that need to be closed. It spawns a goroutine for each closer to ensure they close concurrently.

Installation

Make sure you have Go installed and use:

go get github.com/partyzanex/shutdown@latest

Usage

Appending Closers:

Here's an example showcasing the Lifo strategy, where resources are added to a stack and then closed in a Last-In, First-Out manner:

type MyCloser struct{}

func (c *MyCloser) Close() error {
    return errors.New("my closer error")
}

now we can add our closers to the stack:

lifo := new(Lifo)
closer1 := &MyCloser{}
closer2 := io.NopCloser(nil)

lifo.Append(closer1)
lifo.Append(closer2)

err := lifo.CloseContext(context.Background())
fmt.Println(err)
// Output: my closer error

Closing Resources with Context:

Employ the CloseContext method to facilitate resource shutdown with context backing:

err := lifoCloser.CloseContext(ctx)

Closing Resources without Context:

To terminate resources absent context support, use the Close method:

err := lifoCloser.Close()

Dependencies

• go.uber.org/multierr: A dependency used for amalgamating multiple errors into a unified error.

Recommendations

Make sure you address any errors propagated by the Close or CloseContext functions to effectively manage any complications that arise during the shutdown process.