Add distibuted cache with Redis

cache/memory/cache.go

@@ -0,0 +1,168 @@
+package libpack_cache
+
+import (
+	"bytes"
+	"compress/gzip"
+	"io"
+	"sync"
+	"time"
+)
+
+type CacheEntry struct {
+	ExpiresAt time.Time
+	Value     []byte
+}
+
+type Cache struct {
+	entries        sync.Map
+	globalTTL      time.Duration
+	compressPool   sync.Pool
+	decompressPool sync.Pool
+	sync.RWMutex   // Reintroduced to provide lock methods
+}
+
+func New(globalTTL time.Duration) *Cache {
+	cache := &Cache{
+		globalTTL: globalTTL,
+		compressPool: sync.Pool{
+			New: func() interface{} {
+				w := gzip.NewWriter(nil)
+				return w
+			},
+		},
+		decompressPool: sync.Pool{
+			New: func() interface{} {
+				// Ensure that new is returning a new reader initialized with an empty byte buffer
+				r, _ := gzip.NewReader(bytes.NewReader([]byte{}))
+				return r
+			},
+		},
+	}
+
+	go cache.cleanupRoutine(globalTTL)
+	return cache
+}
+
+func (c *Cache) cleanupRoutine(globalTTL time.Duration) {
+	ticker := time.NewTicker(globalTTL / 2)
+	defer ticker.Stop()
+
+	for range ticker.C {
+		c.CleanExpiredEntries()
+	}
+}
+
+func (c *Cache) Set(key string, value []byte, ttl time.Duration) {
+	c.Lock() // use the lock
+	defer c.Unlock()
+
+	expiresAt := time.Now().Add(ttl)
+
+	compressedValue, err := c.compress(value)
+	if err != nil {
+		return
+	}
+
+	entry := CacheEntry{
+		Value:     compressedValue,
+		ExpiresAt: expiresAt,
+	}
+	c.entries.Store(key, entry)
+}
+
+func (c *Cache) Get(key string) ([]byte, bool) {
+	c.RLock() // use the read lock
+	defer c.RUnlock()
+
+	entry, ok := c.entries.Load(key)
+	if !ok || entry.(CacheEntry).ExpiresAt.Before(time.Now()) {
+		return nil, false
+	}
+	compressedValue := entry.(CacheEntry).Value
+	value, err := c.decompress(compressedValue)
+	if err != nil {
+		return nil, false
+	}
+	return value, true
+}
+
+func (c *Cache) Delete(key string) {
+	c.Lock()
+	defer c.Unlock()
+
+	_, ok := c.entries.Load(key)
+	if !ok {
+		return
+	}
+
+	c.entries.Delete(key)
+}
+
+func (c *Cache) Clear() {
+	c.entries = sync.Map{}
+}
+
+func (c *Cache) CountQueries() int {
+	c.RLock()
+	defer c.RUnlock()
+	var count int
+	c.entries.Range(func(_, _ interface{}) bool {
+		count++
+		return true
+	})
+	return count
+}
+
+func (c *Cache) compress(data []byte) ([]byte, error) {
+	w := c.compressPool.Get().(*gzip.Writer)
+	defer c.compressPool.Put(w)
+
+	var buf bytes.Buffer
+	w.Reset(&buf)
+	if _, err := w.Write(data); err != nil {
+		return nil, err
+	}
+	if err := w.Close(); err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+func (c *Cache) decompress(data []byte) ([]byte, error) {
+	r, ok := c.decompressPool.Get().(*gzip.Reader)
+	if !ok || r == nil {
+		// If r is nil or type assertion fails, create a new gzip.Reader
+		var err error
+		r, err = gzip.NewReader(bytes.NewReader(data))
+		if err != nil {
+			return nil, err // Handle the error if gzip.NewReader fails
+		}
+	} else {
+		// Reset the existing reader with new data
+		if err := r.Reset(bytes.NewReader(data)); err != nil {
+			return nil, err // Handle the error if Reset fails
+		}
+	}
+	defer r.Close()
+
+	// Ensure the reader is returned to the pool
+	defer c.decompressPool.Put(r)
+
+	// Read all the data from the reader
+	decompressedData, err := io.ReadAll(r)
+	if err != nil {
+		return nil, err // Handle the error if reading fails
+	}
+	return decompressedData, nil
+}
+
+func (c *Cache) CleanExpiredEntries() {
+	now := time.Now()
+	c.entries.Range(func(key, value interface{}) bool {
+		entry := value.(CacheEntry)
+		if entry.ExpiresAt.Before(now) {
+			c.entries.Delete(key)
+		}
+		return true
+	})
+}

cache/memory/cache_bench_test.go

@@ -0,0 +1,54 @@
+package libpack_cache
+
+import (
+	"testing"
+	"time"
+)
+
+// Assume that New function initializes the cache and it is defined somewhere in the libpack_cache package.
+
+func BenchmarkCacheSet(b *testing.B) {
+	cache := New(30 * time.Second) // Initializing the cache with a TTL of 30 seconds
+	key := "benchmark-key"
+	value := []byte("benchmark-value")
+
+	b.ResetTimer() // Reset the timer to exclude the setup time from the benchmark
+
+	for i := 0; i < b.N; i++ {
+		cache.Set(key, value, 5*time.Second)
+	}
+}
+
+func BenchmarkCacheGet(b *testing.B) {
+	cache := New(30 * time.Second) // Initializing the cache
+	key := "benchmark-key"
+	value := []byte("benchmark-value")
+	cache.Set(key, value, 5*time.Second) // Pre-set a value to retrieve
+
+	b.ResetTimer() // Start timing
+
+	for i := 0; i < b.N; i++ {
+		_, _ = cache.Get(key)
+	}
+}
+
+func BenchmarkCacheExpire(b *testing.B) {
+	key := "benchmark-expire-key"
+	value := []byte("benchmark-value")
+	ttl := 5 * time.Millisecond // Setting a short TTL for quick expiration
+
+	for i := 0; i < b.N; i++ {
+		cache := New(30 * time.Second)
+		cache.Set(key, value, ttl)
+		time.Sleep(ttl) // Wait for the key to expire
+		_, _ = cache.Get(key)
+	}
+}
+
+func BenchmarkCacheStats(b *testing.B) {
+	cache := New(30 * time.Second) // Initializing the cache
+	key := "benchmark-key"
+	value := []byte("benchmark-value")
+	cache.Set(key, value, 5*time.Second) // Pre-set a value to retrieve
+	cache.Get(key)
+}

cache/memory/cache_test.go

@@ -0,0 +1,112 @@
+package libpack_cache
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/suite"
+)
+
+type CacheTestSuite struct {
+	suite.Suite
+}
+
+func (suite *CacheTestSuite) SetupTest() {
+}
+
+func TestCachingTestSuite(t *testing.T) {
+	suite.Run(t, new(CacheTestSuite))
+}
+
+func (suite *CacheTestSuite) Test_New() {
+	suite.T().Run("should return a new cache", func(t *testing.T) {
+		cache := New(2 * time.Second)
+		suite.NotNil(cache)
+	})
+}
+
+func (suite *CacheTestSuite) Test_CacheUse() {
+	cache := New(30 * time.Second)
+	tests := []struct {
+		name        string
+		cache_value string
+	}{
+		{
+			name:        "test1",
+			cache_value: "test1-123",
+		},
+		{
+			name:        "test2",
+			cache_value: "test2-123",
+		},
+	}
+	for _, tt := range tests {
+		suite.T().Run(tt.name, func(t *testing.T) {
+			cache.Set(tt.name, []byte(tt.name), 5*time.Second)
+			c, ok := cache.Get(tt.name)
+			suite.Equal(true, ok)
+			suite.Equal(tt.name, string(c))
+		})
+	}
+}
+
+func (suite *CacheTestSuite) Test_CacheDelete() {
+	cache := New(30 * time.Second)
+	tests := []struct {
+		name        string
+		cache_value string
+	}{
+		{
+			name:        "test1",
+			cache_value: "test1-123",
+		},
+		{
+			name:        "test2",
+			cache_value: "test2-123",
+		},
+	}
+	for _, tt := range tests {
+		suite.T().Run(tt.name, func(t *testing.T) {
+			cache.Set(tt.name, []byte(tt.name), 5*time.Second)
+			c, ok := cache.Get(tt.name)
+			suite.Equal(true, ok)
+			suite.Equal(tt.name, string(c))
+			cache.Delete(tt.name)
+			c, ok = cache.Get(tt.name)
+			suite.Equal(false, ok)
+			suite.Equal("", string(c))
+		})
+	}
+}
+
+func (suite *CacheTestSuite) Test_CacheExpire() {
+	cache := New(30 * time.Second)
+	tests := []struct {
+		name        string
+		cache_value string
+		ttl         time.Duration
+	}{
+		{
+			name:        "test1",
+			cache_value: "test1-123",
+			ttl:         2 * time.Second,
+		},
+		{
+			name:        "test2",
+			cache_value: "test2-123",
+			ttl:         5 * time.Second,
+		},
+	}
+	for _, tt := range tests {
+		suite.T().Run(tt.name, func(t *testing.T) {
+			cache.Set(tt.name, []byte(tt.name), tt.ttl)
+			c, ok := cache.Get(tt.name)
+			suite.Equal(true, ok)
+			suite.Equal(tt.name, string(c))
+			time.Sleep(tt.ttl)
+			c, ok = cache.Get(tt.name)
+			suite.Equal(false, ok)
+			suite.Equal("", string(c))
+		})
+	}
+}