client side cache

pkg/client/client.go

@@ -1,12 +1,10 @@
 package client
 
 import (
-	"bytes"
 	"encoding/binary"
-	"encoding/json"
 	"fmt"
-	"log"
 	"net/http"
+	"sync"
 	"time"
 
 	"git.tijl.dev/tijl/shortify/pkg/generation"
@@ -18,21 +16,26 @@ type Client struct {
 	httpClient *http.Client
 	prefix     uint16
 	gen        *generation.Generator
-	domain     string // e.g. https://sho.rt
 
 	db         *bolt.DB
 	retryQueue chan shortenJob
 	stopRetry  chan struct{}
+
+	// In-memory cache
+	cacheMap     map[string]string // longURL -> shortID
+	cacheLock    sync.RWMutex
+	maxCacheSize int
+	cacheCount   int
 }
 
 // NewClient with persistence and retry queue
-func NewClient(serverURL, domain string) (*Client, error) {
+func NewClient(serverURL string, folder string) (*Client, error) {
 	httpClient, baseURL, err := createHTTPClient(serverURL)
 	if err != nil {
 		return nil, err
 	}
 
-	db, err := bolt.Open(dbFileName, 0600, &bolt.Options{Timeout: 1 * time.Second})
+	db, err := bolt.Open(folder+"/"+dbFileName, 0600, &bolt.Options{Timeout: 1 * time.Second})
 	if err != nil {
 		return nil, err
 	}
@@ -40,12 +43,15 @@ func NewClient(serverURL, domain string) (*Client, error) {
 	cli := &Client{
 		serverURL:  baseURL,
 		httpClient: httpClient,
-		domain:     domain,
 		db:         db,
 		retryQueue: make(chan shortenJob, 1000),
 		stopRetry:  make(chan struct{}),
 	}
 
+	cli.cacheMap = make(map[string]string)
+	cli.maxCacheSize = 10000 // or make this configurable
+	cli.cacheCount = 0
+
 	// Create buckets if not exist
 	err = db.Update(func(tx *bolt.Tx) error {
 		_, err := tx.CreateBucketIfNotExists([]byte(bucketPrefix))
@@ -53,7 +59,16 @@ func NewClient(serverURL, domain string) (*Client, error) {
 			return err
 		}
 		_, err = tx.CreateBucketIfNotExists([]byte(bucketRetryJobs))
-		return err
+		if err != nil {
+			return err
+		}
+
+		_, err = tx.CreateBucketIfNotExists([]byte(bucketURLCache))
+		if err != nil {
+			return err
+		}
+
+		return nil
 	})
 	if err != nil {
 		return nil, err
@@ -96,6 +111,20 @@ func NewClient(serverURL, domain string) (*Client, error) {
 	cli.prefix = prefix
 	cli.gen = generation.NewGenerator(prefix)
 
+	// load cache
+	_ = cli.db.View(func(tx *bolt.Tx) error {
+		b := tx.Bucket([]byte("url_cache"))
+		if b == nil {
+			return nil
+		}
+		c := b.Cursor()
+		for k, v := c.First(); k != nil && cli.cacheCount < cli.maxCacheSize; k, v = c.Next() {
+			cli.cacheMap[string(k)] = string(v)
+			cli.cacheCount++
+		}
+		return nil
+	})
+
 	// Load retry jobs from DB into channel
 	go cli.loadRetryJobs()
 
@@ -105,31 +134,68 @@ func NewClient(serverURL, domain string) (*Client, error) {
 	return cli, nil
 }
 
-// Shorten creates a short URL and sends it async to the central server
-func (c *Client) Shorten(longURL string) string {
+/*
+Shorten
+*/
+
+type ShortenOpt func(*shortenOptions)
+
+type shortenOptions struct {
+	useCache bool
+}
+
+func UseCache() ShortenOpt {
+	return func(opts *shortenOptions) {
+		opts.useCache = true
+	}
+}
+
+func (c *Client) Shorten(longURL string, opts ...ShortenOpt) string {
+	options := shortenOptions{}
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	// Check memory cache
+	if options.useCache {
+		c.cacheLock.RLock()
+		if shortID, ok := c.cacheMap[longURL]; ok {
+			c.cacheLock.RUnlock()
+			return shortID
+		}
+		c.cacheLock.RUnlock()
+	}
+
+	// Generate new ID
 	shortID := c.gen.NextID()
 
-	go func() {
-		payload := map[string]string{
-			"id":  shortID,
-			"url": longURL,
-		}
-		data, _ := json.Marshal(payload)
+	// Queue job
+	go c.enqueueJob(shortenJob{
+		ID:  shortID,
+		URL: longURL,
+	})
 
-		req, err := http.NewRequest("POST", fmt.Sprintf("%s/shorten", c.serverURL), bytes.NewReader(data))
-		if err != nil {
-			log.Println("shorten request build error:", err)
-			return
-		}
-		req.Header.Set("Content-Type", "application/json")
+	// Async store in cache
+	if options.useCache {
+		go c.addToCache(longURL, shortID)
+	}
 
-		resp, err := c.httpClient.Do(req)
-		if err != nil {
-			log.Println("shorten request failed:", err)
-			return
-		}
-		defer resp.Body.Close()
-	}()
-
-	return fmt.Sprintf("%s/%s", c.domain, shortID)
+	return shortID
+}
+
+func (c *Client) addToCache(longURL, shortID string) {
+	c.cacheLock.Lock()
+	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() {
+		_ = c.db.Update(func(tx *bolt.Tx) error {
+			b := tx.Bucket([]byte("url_cache"))
+			return b.Put([]byte(longURL), []byte(shortID))
+		})
+	}()
 }

pkg/client/global.go

@@ -0,0 +1,16 @@
+package client
+
+import "sync"
+
+var (
+	Global *Client
+	once   sync.Once
+)
+
+func Init(serverURL string, folder string) error {
+	var err error
+	once.Do(func() {
+		Global, err = NewClient(serverURL, folder)
+	})
+	return err
+}

pkg/client/store.go

@@ -1,11 +1,13 @@
 package client
 
 import (
-	"bytes"
+	"encoding/binary"
 	"encoding/json"
 	"fmt"
+	"io"
 	"log"
 	"net/http"
+	"strings"
 	"time"
 
 	bolt "go.etcd.io/bbolt"
@@ -14,6 +16,7 @@ import (
 const (
 	bucketPrefix    = "prefix"
 	bucketRetryJobs = "retry_queue"
+	bucketURLCache  = "url_cache"
 	dbFileName      = "shorty_client.db"
 )
 
@@ -23,19 +26,18 @@ type shortenJob struct {
 }
 
 func (c *Client) registerPrefix() (uint16, error) {
-	resp, err := c.httpClient.Post(fmt.Sprintf("%s/register", c.serverURL), "application/json", nil)
+	resp, err := c.httpClient.Get(fmt.Sprintf("%s/register", c.serverURL))
 	if err != nil {
 		return 0, err
 	}
 	defer resp.Body.Close()
 
-	var result struct {
-		Prefix uint16 `json:"prefix"`
-	}
-	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+	bytes, err := io.ReadAll(resp.Body)
+	if err != nil {
 		return 0, err
 	}
-	return result.Prefix, nil
+
+	return binary.LittleEndian.Uint16(bytes), nil
 }
 
 func (c *Client) loadRetryJobs() {
@@ -108,18 +110,10 @@ func (c *Client) deleteJobFromDB(job shortenJob) {
 }
 
 func (c *Client) sendShortenJob(job shortenJob) error {
-	payload := map[string]string{
-		"id":  job.ID,
-		"url": job.URL,
-	}
-	data, _ := json.Marshal(payload)
-
-	req, err := http.NewRequest("POST", fmt.Sprintf("%s/shorten", c.serverURL), bytes.NewReader(data))
+	req, err := http.NewRequest("POST", fmt.Sprintf("%s/shorten?s=%s", c.serverURL, job.ID), strings.NewReader(job.URL))
 	if err != nil {
 		return err
 	}
-	req.Header.Set("Content-Type", "application/json")
-
 	resp, err := c.httpClient.Do(req)
 	if err != nil {
 		return err

serve.go

@@ -16,19 +16,22 @@ func (s *Server) Admin() *fiber.App {
 		if err != nil {
 			return err
 		}
-		var response []byte
+		response := make([]byte, 2)
 		binary.LittleEndian.PutUint16(response, prefix)
 		return c.Send(response)
 	})
 
 	a.Post("/shorten", func(c *fiber.Ctx) error {
+		longUrl := string(c.Body())
 		shortUrl := c.Query("s")
 		if shortUrl == "" {
 			shortUrl = s.serverGen.NextID()
 		}
-		longUrl := string(c.Body())
-
-		return s.storage.Put(shortUrl, longUrl)
+		err := s.storage.Put(shortUrl, longUrl)
+		if err != nil {
+			return err
+		}
+		return c.SendString(shortUrl)
 	})
 
 	return a

server.go

@@ -38,7 +38,7 @@ func (s *Server) HandleGetURL() func(*fiber.Ctx) error {
 
 		url, err := s.GetURL(shortID)
 		if err != nil {
-			return err
+			return c.Next()
 		}
 
 		s.LogVisit(VisitLog{