Init

example/del-keys-without-ttl/main.go

@@ -0,0 +1,155 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"sync"
+	"time"
+
+	"go.uber.org/zap"
+
+	"github.com/redis/go-redis/v9"
+)
+
+func main() {
+	ctx := context.Background()
+
+	rdb := redis.NewClient(&redis.Options{
+		Addr: ":6379",
+	})
+
+	_ = rdb.Set(ctx, "key_with_ttl", "bar", time.Minute).Err()
+	_ = rdb.Set(ctx, "key_without_ttl_1", "", 0).Err()
+	_ = rdb.Set(ctx, "key_without_ttl_2", "", 0).Err()
+
+	checker := NewKeyChecker(rdb, 100)
+
+	start := time.Now()
+	checker.Start(ctx)
+
+	iter := rdb.Scan(ctx, 0, "", 0).Iterator()
+	for iter.Next(ctx) {
+		checker.Add(iter.Val())
+	}
+	if err := iter.Err(); err != nil {
+		panic(err)
+	}
+
+	deleted := checker.Stop()
+	fmt.Println("deleted", deleted, "keys", "in", time.Since(start))
+}
+
+type KeyChecker struct {
+	rdb       *redis.Client
+	batchSize int
+	ch        chan string
+	delCh     chan string
+	wg        sync.WaitGroup
+	deleted   int
+	logger    *zap.Logger
+}
+
+func NewKeyChecker(rdb *redis.Client, batchSize int) *KeyChecker {
+	return &KeyChecker{
+		rdb:       rdb,
+		batchSize: batchSize,
+		ch:        make(chan string, batchSize),
+		delCh:     make(chan string, batchSize),
+		logger:    zap.L(),
+	}
+}
+
+func (c *KeyChecker) Add(key string) {
+	c.ch <- key
+}
+
+func (c *KeyChecker) Start(ctx context.Context) {
+	c.wg.Add(1)
+	go func() {
+		defer c.wg.Done()
+		if err := c.del(ctx); err != nil {
+			panic(err)
+		}
+	}()
+
+	c.wg.Add(1)
+	go func() {
+		defer c.wg.Done()
+		defer close(c.delCh)
+
+		keys := make([]string, 0, c.batchSize)
+
+		for key := range c.ch {
+			keys = append(keys, key)
+			if len(keys) < cap(keys) {
+				continue
+			}
+
+			if err := c.checkKeys(ctx, keys); err != nil {
+				c.logger.Error("checkKeys failed", zap.Error(err))
+			}
+			keys = keys[:0]
+		}
+
+		if len(keys) > 0 {
+			if err := c.checkKeys(ctx, keys); err != nil {
+				c.logger.Error("checkKeys failed", zap.Error(err))
+			}
+			keys = nil
+		}
+	}()
+}
+
+func (c *KeyChecker) Stop() int {
+	close(c.ch)
+	c.wg.Wait()
+	return c.deleted
+}
+
+func (c *KeyChecker) checkKeys(ctx context.Context, keys []string) error {
+	cmds, err := c.rdb.Pipelined(ctx, func(pipe redis.Pipeliner) error {
+		for _, key := range keys {
+			pipe.TTL(ctx, key)
+		}
+		return nil
+	})
+	if err != nil {
+		return err
+	}
+
+	for i, cmd := range cmds {
+		d, err := cmd.(*redis.DurationCmd).Result()
+		if err != nil {
+			return err
+		}
+		if d == -1 {
+			c.delCh <- keys[i]
+		}
+	}
+
+	return nil
+}
+
+func (c *KeyChecker) del(ctx context.Context) error {
+	pipe := c.rdb.Pipeline()
+
+	for key := range c.delCh {
+		fmt.Printf("deleting %s...\n", key)
+		pipe.Del(ctx, key)
+		c.deleted++
+
+		if pipe.Len() < c.batchSize {
+			continue
+		}
+
+		if _, err := pipe.Exec(ctx); err != nil {
+			return err
+		}
+	}
+
+	if _, err := pipe.Exec(ctx); err != nil {
+		return err
+	}
+
+	return nil
+}