ore

ore - Generic Dependency Injection Container for Go

ore is a lightweight, generic & simple dependency injection (DI) container for Go.

Inspired by the principles of ASP.NET Dependency Injection, designed to facilitate the management of object lifetimes and the inversion of control in your applications.

Features

• Singletons: Register components as singletons, ensuring that there's only one instance throughout the entire application.

• Transients: Register components as transients, creating a new instance each time it is requested.

• Scoped Instances: Register components as scoped, tying them to a specific context or scope. Scoped components are created once per scope and reused within that scope.

• Lazy Initialization: Support for lazy initialization of components, allowing for efficient resource utilization.

• Multiple Implementations of the Same Interface: Register and retrieve several implementations of the same interface type, allowing for flexible and modular design.

• Keyed Services Injection: Support for injecting services based on a key, allowing you to differentiate between multiple implementations of the same interface or type.

• Concurrency-Safe: Utilizes a mutex to ensure safe concurrent access to the container.

Installation

go get -u github.com/firasdarwish/ore

Usage

Import

import "github.com/firasdarwish/ore"

Example Service

// interface
type Counter interface {
  AddOne()
  GetCount() int
}

// implementation
type simpleCounter struct {
  counter int
}

func (c *simpleCounter) AddOne()  {
  c.counter++
}

func (c *simpleCounter) GetCount() int {
  return c.counter
}

func (c *simpleCounter) New(ctx context.Context) Counter {
  return &simpleCounter{}
}

Eager Singleton

package main

import (
  "context"
  "github.com/firasdarwish/ore"
)

func main() {
  var c Counter
  c = &simpleCounter{}

  // register
  ore.RegisterEagerSingleton[Counter](c)

  ctx := context.Background()

  // retrieve
  c, ctx := ore.Get[Counter](ctx)
  c.AddOne()
  c.AddOne()
}

Lazy (using Creator[T] interface)

package main

import (
  "context"
  "fmt"
  "github.com/firasdarwish/ore"
)

func main() {
  // register
  ore.RegisterLazyCreator[Counter](ore.Scoped, &simpleCounter{})

  // OR
  //ore.RegisterLazyCreator[Counter](ore.Transient, &simpleCounter{})
  //ore.RegisterLazyCreator[Counter](ore.Singleton, &simpleCounter{})

  ctx := context.Background()

  // retrieve
  c, ctx := ore.Get[Counter](ctx)
  c.AddOne()
  c.AddOne()

  // retrieve again
  c, ctx = ore.Get[Counter](ctx)
  c.AddOne()

  // prints out: `TOTAL: 3`
  fmt.Println("TOTAL: ", c.GetCount())
}

Lazy (using anonymous func)

package main

import (
  "context"
  "fmt"
  "github.com/firasdarwish/ore"
)

func main() {
  // register
  ore.RegisterLazyFunc[Counter](ore.Scoped, func(ctx context.Context) Counter {
    return &simpleCounter{}
  })

  // OR
  //ore.RegisterLazyFunc[Counter](ore.Transient, func(ctx context.Context) Counter {
  //  return &simpleCounter{}
  //})

  // Keyed service registration
  //ore.RegisterLazyFunc[Counter](ore.Singleton, func(ctx context.Context) Counter {
  // return &simpleCounter{}
  //}, "name here", 1234)

  ctx := context.Background()

  // retrieve
  c, ctx := ore.Get[Counter](ctx)
  c.AddOne()
  c.AddOne()

  // Keyed service retrieval
  //c, ctx := ore.Get[Counter](ctx, "name here", 1234)

  // retrieve again
  c, ctx = ore.Get[Counter](ctx)
  c.AddOne()

  // prints out: `TOTAL: 3`
  fmt.Println("TOTAL: ", c.GetCount())
}

Several Implementations

package main

import (
  "context"
  "github.com/firasdarwish/ore"
)

func main() {
  // register
  ore.RegisterLazyCreator[Counter](ore.Scoped, &simpleCounter{})

  ore.RegisterLazyCreator[Counter](ore.Scoped, &yetAnotherCounter{})

  ore.RegisterLazyFunc[Counter](ore.Transient, func(ctx context.Context) Counter {
    return &simpleCounter{}
  })

  ore.RegisterLazyCreator[Counter](ore.Singleton, &yetAnotherCounter{})

  ctx := context.Background()

  // returns a slice of `Counter` implementations
  counters, ctx := ore.GetList[Counter](ctx)

  // to retrieve a slice of keyed services
  //counters, ctx := ore.GetList[Counter](ctx, "my integer counters")

  for _, c := range counters {
    c.AddOne()
  }

  // It will always return the LAST registered implementation
  defaultImplementation, ctx := ore.Get[Counter](ctx) // simpleCounter
  defaultImplementation.AddOne()
}

Keyed Services Retrieval Example

package main

import (
  "context"
  "fmt"
  "github.com/firasdarwish/ore"
)

func main() {
  // register
  ore.RegisterLazyFunc[Counter](ore.Singleton, func(ctx context.Context) Counter {
    return &simpleCounter{}
  }, "name here", 1234)

  //ore.RegisterLazyCreator[Counter](ore.Scoped, &simpleCounter{}, "name here", 1234)

  //ore.RegisterEagerSingleton[Counter](&simpleCounter{}, "name here", 1234)

  ctx := context.Background()

  // Keyed service retrieval
  c, ctx := ore.Get[Counter](ctx, "name here", 1234)
  c.AddOne()

  // prints out: `TOTAL: 1`
  fmt.Println("TOTAL: ", c.GetCount())
}

More Complex Example

type Numeric interface {
	int
}

type GenericCounter[T Numeric] interface {
  Add(number T)
  GetCount() T
}

type genericCounter[T Numeric] struct {
  counter T
}

func (gc *genericCounter[T]) Add(number T) {
  gc.counter += number
}

func (gc *genericCounter[T]) GetCount(ctx context.Context) T {
  return gc.counter
}

package main

import (
  "context"
  "github.com/firasdarwish/ore"
)

func main() {

  // register
  ore.RegisterLazyFunc[GenericCounter[int]](ore.Scoped, func(ctx context.Context) GenericCounter[int] {
    return &genericCounter[int]{}
  })

  // retrieve
  c, ctx := ore.Get[GenericCounter[int]](ctx)
}

Benchmarks

goos: windows
goarch: amd64
pkg: github.com/firasdarwish/ore
cpu: 13th Gen Intel(R) Core(TM) i9-13900H
BenchmarkRegisterLazyFunc
BenchmarkRegisterLazyFunc-20             5404572               209.6 ns/op
BenchmarkRegisterLazyCreator
BenchmarkRegisterLazyCreator-20          5683119               195.5 ns/op
BenchmarkRegisterEagerSingleton
BenchmarkRegisterEagerSingleton-20       5335443               218.8 ns/op
BenchmarkGet
BenchmarkGet-20                          4231207               279.8 ns/op
BenchmarkGetList
BenchmarkGetList-20                      2098818               544.6 ns/op

Contributing

Feel free to contribute by opening issues, suggesting features, or submitting pull requests. We welcome your feedback and contributions.

License

This project is licensed under the MIT License - see the LICENSE file for details.