What is caching and why is it needed?

Caching is the process of storing the results of expensive operations (such as computations, database queries, or external service calls) in fast-access storage so that subsequent requests can use the already computed data instead of performing the operation again.

Why caching is needed:

• It speeds up the application by reducing response time.
• It reduces load on resources (DB, network, CPU).
• It increases system scalability.

In Go, caching is often implemented using built-in data structures (map) or specialized libraries, for example, for in-memory cache. Here's a simple example of a cache in Go:

package main

import (
    "fmt"
    "sync"
    "time"
)

type Cache struct {
    mu    sync.Mutex
    store map[string]string
}

func NewCache() *Cache {
    return &Cache{store: make(map[string]string)}
}

func (c *Cache) Get(key string) (string, bool) {
    c.mu.Lock()
    defer c.mu.Unlock()
    val, ok := c.store[key]
    return val, ok
}

func (c *Cache) Set(key, value string) {
    c.mu.Lock()
    defer c.mu.Unlock()
    c.store[key] = value
}

func main() {
    cache := NewCache()
    cache.Set("time", time.Now().String())

    if val, ok := cache.Get("time"); ok {
        fmt.Println("Cached value:", val)
    }
}