Caching in Laravel & PHP

Great question 👍 Let’s cover caching in PHP (raw) and then how Laravel makes it much easier and powerful.

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🧠 1. What is Caching?

Caching means storing data temporarily so you don’t need to recalculate or refetch it every time.

• Speeds up performance 🚀
• Reduces database/API load
• Stores in memory (Redis/Memcached) or files

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🐘 2. Caching in Plain PHP

In raw PHP, you don’t have a built-in cache system like Laravel, but you can implement simple ones.

Example 1: File-based Cache

<?php
function getCache($key) {
    $file = __DIR__ . "/cache/{$key}.txt";
    if (file_exists($file) && (time() - filemtime($file) < 60)) {
        // valid cache for 60 sec
        return file_get_contents($file);
    }
    return null;
}

function setCache($key, $data) {
    $file = __DIR__ . "/cache/{$key}.txt";
    file_put_contents($file, $data);
}

// Example: Caching API result
$data = getCache("users");

if (!$data) {
    echo "Fetching fresh data...\n";
    $data = json_encode(["Ahmed", "Ali", "Sara"]);
    setCache("users", $data);
} else {
    echo "Using cache...\n";
}

echo $data;

✅ First time → fetches fresh data
✅ Next times (within 60 sec) → returns cache

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Example 2: Memory Caching with APCu (if installed)

<?php
apcu_store('name', 'Ahmed', 60); // store 60 sec
echo apcu_fetch('name'); // Ahmed

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🎯 3. Caching in Laravel (Much Easier!)

Laravel comes with a powerful cache system out of the box.
Supported drivers: file, database, array, redis, memcached.
Default in .env:

CACHE_DRIVER=file

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🔹 Basic Cache Usage

use Illuminate\Support\Facades\Cache;

// Store
Cache::put('name', 'Ahmed', 60); // 60 seconds

// Retrieve
$name = Cache::get('name'); // Ahmed

// Retrieve with default
$name = Cache::get('username', 'Guest');

// Check
if (Cache::has('name')) {
    echo "Cache exists!";
}

// Delete
Cache::forget('name');

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🔹 Remember Pattern

Very common in Laravel:

$users = Cache::remember('users', 60, function () {
    return DB::table('users')->get();
});

➡️ First time → runs the DB query, caches it for 60 sec
➡️ Next time → pulls from cache directly

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🔹 Forever Cache

Cache::forever('site_settings', ['theme' => 'dark']);

Remove it:

Cache::forget('site_settings');

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⚡ 4. Real-World Example: API Caching

public function getWeather() {
    return Cache::remember('weather_data', 600, function () {
        $response = Http::get('https://api.weatherapi.com/v1/current.json?key=API_KEY&q=London');
        return $response->json();
    });
}

✅ Saves API response for 10 minutes.
✅ Avoids calling external API every time.

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🔔 5. Best Practices

• Use Redis for high-performance caching in production.
• Use remember or rememberForever instead of manually managing put/get.
• Clear cache safely:

  php artisan cache:clear

• For config caching:

  php artisan config:cache

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✅ In short:

• In PHP, you can use files or APCu for caching.
• In Laravel, use Cache facade → simple and powerful (DB, Redis, Memcached, File).
• Perfect for speeding up DB queries, API calls, or expensive calculations.

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Perfect 👌 Redis is one of the fastest ways to do caching in Laravel (and plain PHP too). Let’s break it down with easy examples.

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🔥 1. What is Redis?

• An in-memory data store (everything is in RAM → super fast ⚡).
• Supports strings, lists, sets, hashes.
• Used for caching, sessions, queues, pub/sub messaging.

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🐘 2. Redis in Plain PHP

To use Redis in PHP, you install the phpredis extension or use Predis (PHP client).

Example (Predis):

require 'vendor/autoload.php';

$redis = new Predis\Client();

// Store in cache
$redis->setex("name", 60, "Ahmed"); // store for 60 sec

// Get from cache
echo $redis->get("name"); // Ahmed

// Delete
$redis->del("name");

✅ Works just like a key-value store.
✅ But Laravel makes it even easier.

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🎯 3. Redis in Laravel

🔹 Step 1: Install Redis

Make sure Redis is installed on your system and running:

redis-server

Install PHP extension (if needed):

composer require predis/predis

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🔹 Step 2: Configure in .env

CACHE_DRIVER=redis
QUEUE_CONNECTION=redis
SESSION_DRIVER=redis

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🔹 Step 3: Use Redis via Cache Facade

use Illuminate\Support\Facades\Cache;

// Store data
Cache::put('username', 'Ahmed', 60); // 60 sec

// Get data
echo Cache::get('username'); // Ahmed

// Remember (common use case)
$users = Cache::remember('users', 300, function () {
    return DB::table('users')->get();
});

// Forget
Cache::forget('username');

✅ Now instead of storing in files, Laravel stores in Redis memory.

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📊 4. Example: Cache Heavy Query with Redis

Route::get('/top-users', function () {
    $users = Cache::remember('top_users', 600, function () {
        return DB::table('users')
            ->orderBy('points', 'desc')
            ->limit(10)
            ->get();
    });

    return $users;
});

➡️ First call → hits DB, stores in Redis.
➡️ Next calls (10 min) → served instantly from Redis.

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🔔 5. Example: Cache API Response with Redis

public function getWeather()
{
    return Cache::remember('weather_london', 900, function () {
        return Http::get('https://api.weatherapi.com/v1/current.json?key=API_KEY&q=London')
            ->json();
    });
}

✅ The API response is cached in Redis for 15 min.
✅ No need to re-hit the external API.

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🛠️ 6. Using Redis Facade Directly (Low-level)

use Illuminate\Support\Facades\Redis;

// Store
Redis::set('site_name', 'My Laravel App');

// Get
echo Redis::get('site_name');

// Increment counter
Redis::incr('visits');

// Lists
Redis::rpush('queue', 'task1');
Redis::rpush('queue', 'task2');
echo Redis::lpop('queue'); // task1

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✅ In Summary

• Plain PHP → use Predis or phpredis.
• Laravel → just set CACHE_DRIVER=redis and use Cache or Redis facade.

• Best for:

  • Heavy DB queries
  • API results
  • Session & authentication data
  • Queues

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