What is State Pattern? The State pattern is a behavioral design pattern that allows an object to alter its behavior when its internal state changes. It appears as if the object changed its class. Think of it like a vending machine - it behaves differently when it’s waiting for coins, has coins inserted, is dispensing a product, or is out of stock. Each state has its own set of valid operations and transitions....
What is Template Method Pattern? The Template Method pattern is a behavioral design pattern that defines the skeleton of an algorithm in a base class and lets subclasses override specific steps without changing the algorithm’s structure. Think of it like a recipe - the overall cooking process is the same (prepare ingredients, cook, serve), but the specific steps can vary depending on what you’re making. In Go, since we don’t have traditional inheritance, we implement this pattern using composition and interfaces, which actually makes it more flexible and idiomatic....
Go Concurrency Patterns Series: ← Select Statement | Series Overview | Fan-Out/Fan-In → What is the Pipeline Pattern? The Pipeline pattern is a powerful way to structure concurrent data processing by breaking work into stages connected by channels. Each stage runs in its own goroutine, receives data from an input channel, processes it, and sends results to an output channel. This creates a chain of processing stages that can run concurrently, dramatically improving throughput....
Go Concurrency Patterns Series: ← Channel Fundamentals | Series Overview | Pipeline Pattern → What is the Select Statement? The select statement is Go’s powerful tool for handling multiple channel operations simultaneously. It’s like a switch statement, but for channels - it allows a goroutine to wait on multiple communication operations and proceed with whichever one becomes ready first. Think of select as a traffic controller at an intersection, managing multiple lanes of traffic (channels) and allowing the first available lane to proceed....
Go Concurrency Patterns Series: ← Goroutine Basics | Series Overview | Select Statement → What are Channels? Channels are Go’s primary mechanism for communication between goroutines. They embody Go’s concurrency philosophy: “Don’t communicate by sharing memory; share memory by communicating.” Think of channels as typed pipes that allow goroutines to safely pass data back and forth. Channels provide both communication and synchronization, making them incredibly powerful for building concurrent applications....
What is Command Pattern? The Command pattern is a behavioral design pattern that turns a request into a stand-alone object containing all information about the request. This transformation allows you to parameterize methods with different requests, delay or queue a request’s execution, and support undoable operations. Think of it like a remote control - each button is a command that encapsulates the action to be performed on a device. I’ll demonstrate how this pattern can help you build flexible, undoable, and queueable operations in Go applications....
Go Concurrency Patterns Series: Series Overview | Channel Fundamentals → What are Goroutines? Goroutines are lightweight threads managed by the Go runtime. They’re one of Go’s most powerful features, allowing you to write concurrent programs that can handle thousands of simultaneous operations with minimal overhead. Think of goroutines as extremely efficient workers that can run independently while sharing the same memory space. Unlike traditional threads that typically consume 1-2MB of memory each, goroutines start with just 2KB of stack space and grow as needed....
Go Concurrency Patterns Series: ← Semaphore Pattern | Series Overview What is the Actor Model? The Actor Model is a conceptual model for concurrent computation where “actors” are the fundamental units of computation. Each actor has its own isolated state, processes messages sequentially, and can create other actors, send messages, or change its behavior in response to messages. Key Principles: Isolated State: Each actor maintains its own private state Message Passing: Actors communicate only through asynchronous messages Sequential Processing: Each actor processes one message at a time Location Transparency: Actors can be local or remote Fault Tolerance: Actor failures are isolated and recoverable Real-World Use Cases Distributed Systems: Microservices communication Game Servers: Player state management IoT Systems: Device state and communication Financial Systems: Transaction processing Chat Applications: User session management Workflow Engines: Task orchestration Basic Actor Implementation package main import ( "context" "fmt" "sync" "time" ) // Message represents a message sent to an actor type Message interface{} // Actor represents the basic actor interface type Actor interface { Receive(message Message) Start(ctx context....
Go Concurrency Patterns Series: ← Context Pattern | Series Overview | Rate Limiter → What is the Circuit Breaker Pattern? The Circuit Breaker pattern prevents cascading failures in distributed systems by monitoring for failures and temporarily stopping calls to failing services. Like an electrical circuit breaker, it “trips” when failures exceed a threshold, giving the failing service time to recover. States: Closed: Normal operation, requests pass through Open: Failing fast, requests are rejected immediately Half-Open: Testing if service has recovered Real-World Use Cases Microservices: Prevent cascade failures between services Database Connections: Handle database outages gracefully External APIs: Deal with third-party service failures Payment Processing: Handle payment gateway issues File Systems: Manage disk I/O failures Network Operations: Handle network partitions Basic Circuit Breaker Implementation package main import ( "context" "errors" "fmt" "sync" "time" ) // State represents the circuit breaker state type State int const ( StateClosed State = iota StateOpen StateHalfOpen ) func (s State) String() string { switch s { case StateClosed: return "CLOSED" case StateOpen: return "OPEN" case StateHalfOpen: return "HALF_OPEN" default: return "UNKNOWN" } } // CircuitBreaker implements the circuit breaker pattern type CircuitBreaker struct { mu sync....
Go Concurrency Patterns Series: ← Once Pattern | Series Overview | Circuit Breaker → What is the Context Pattern? The Context pattern uses Go’s context package to carry cancellation signals, deadlines, timeouts, and request-scoped values across API boundaries and between goroutines. It’s essential for building responsive, cancellable operations and managing request lifecycles. Key Features: Cancellation: Signal when operations should stop Timeouts: Automatically cancel after a duration Deadlines: Cancel at a specific time Values: Carry request-scoped data Real-World Use Cases HTTP Servers: Request cancellation and timeouts Database Operations: Query timeouts and cancellation API Calls: External service timeouts Background Jobs: Graceful shutdown Microservices: Request tracing and correlation IDs File Operations: Long-running I/O with cancellation Basic Context Usage package main import ( "context" "fmt" "math/rand" "time" ) // simulateWork simulates a long-running operation func simulateWork(ctx context....