use lru for client side cache

pkg/client/client.go

@@ -4,10 +4,10 @@ import (
 	"encoding/binary"
 	"fmt"
 	"net/http"
-	"sync"
 	"time"
 
 	"git.tijl.dev/tijl/shortify/pkg/generation"
+	lru "github.com/hashicorp/golang-lru"
 	bolt "go.etcd.io/bbolt"
 )
 
@@ -22,10 +22,9 @@ type Client struct {
 	stopRetry  chan struct{}
 
 	// In-memory cache
-	cacheMap     map[string]string // longURL -> shortID
+	cacheMap            *lru.Cache
-	cacheLock    sync.RWMutex
+	maxCacheSize        int
-	maxCacheSize int
+	maxCacheInitialLoad int
-	cacheCount   int
 }
 
 // NewClient with persistence and retry queue
@@ -48,9 +47,12 @@ func NewClient(serverURL string, folder string) (*Client, error) {
 		stopRetry:  make(chan struct{}),
 	}
 
-	cli.cacheMap = make(map[string]string)
+	cli.cacheMap, err = lru.New(cli.maxCacheSize)
-	cli.maxCacheSize = 10000 // or make this configurable
+	if err != nil {
-	cli.cacheCount = 0
+		return nil, err
+	}
+	cli.maxCacheSize = 100000 // or make this configurable
+	cli.maxCacheInitialLoad = 10000
 
 	// Create buckets if not exist
 	err = db.Update(func(tx *bolt.Tx) error {
@@ -118,9 +120,10 @@ func NewClient(serverURL string, folder string) (*Client, error) {
 			return nil
 		}
 		c := b.Cursor()
-		for k, v := c.First(); k != nil && cli.cacheCount < cli.maxCacheSize; k, v = c.Next() {
+		initalCounter := 0
-			cli.cacheMap[string(k)] = string(v)
+		for k, v := c.First(); k != nil && initalCounter < cli.maxCacheInitialLoad; k, v = c.Next() {
-			cli.cacheCount++
+			cli.cacheMap.Add(string(k), string(v))
+			initalCounter++
 		}
 		return nil
 	})
@@ -158,12 +161,9 @@ func (c *Client) Shorten(longURL string, opts ...ShortenOpt) string {
 
 	// Check memory cache
 	if options.useCache {
-		c.cacheLock.RLock()
+		if shortID, ok := c.cacheMap.Get(longURL); ok {
-		if shortID, ok := c.cacheMap[longURL]; ok {
+			return shortID.(string)
-			c.cacheLock.RUnlock()
-			return shortID
 		}
-		c.cacheLock.RUnlock()
 	}
 
 	// Generate new ID
@@ -184,12 +184,7 @@ func (c *Client) Shorten(longURL string, opts ...ShortenOpt) string {
 }
 
 func (c *Client) addToCache(longURL, shortID string) {
-	c.cacheLock.Lock()
+	c.cacheMap.Add(longURL, shortID)
-	if _, exists := c.cacheMap[longURL]; !exists && c.cacheCount < c.maxCacheSize {
-		c.cacheMap[longURL] = shortID
-		c.cacheCount++
-	}
-	c.cacheLock.Unlock()
 
 	// Async write to BoltDB
 	go func() {