// Copyright 2023 The Gitea Authors. All rights reserved.// SPDX-License-Identifier: MIT package queue import (	"context"	"sync"	"time" 	"forgejo.org/modules/graceful"	"forgejo.org/modules/log"	"forgejo.org/modules/nosql" 	"github.com/redis/go-redis/v9") type baseRedis struct {	client   nosql.RedisClient	isUnique bool	cfg      *BaseConfig	prefix   string 	mu sync.Mutex // the old implementation is not thread-safe, the queue operation and set operation should be protected together} var _ baseQueue = (*baseRedis)(nil) func newBaseRedisGeneric(cfg *BaseConfig, unique bool, client nosql.RedisClient) (baseQueue, error) {	if client == nil {		client = nosql.GetManager().GetRedisClient(cfg.ConnStr)	} 	prefix := ""	uri := nosql.ToRedisURI(cfg.ConnStr) 	for key, value := range uri.Query() {		switch key {		case "prefix":			if len(value) > 0 {				prefix = value[0] 				// As we are not checking any other values, if we found this one, we can				// exit from the loop.				// If a new key check is required, remove this break.				break			}		}	} 	var err error	for i := 0; i < 10; i++ {		err = client.Ping(graceful.GetManager().ShutdownContext()).Err()		if err == nil {			break		}		log.Warn("Redis is not ready, waiting for 1 second to retry: %v", err)		time.Sleep(time.Second)	}	if err != nil {		return nil, err	} 	return &baseRedis{cfg: cfg, client: client, isUnique: unique, prefix: prefix}, nil} func newBaseRedisSimple(cfg *BaseConfig) (baseQueue, error) {	return newBaseRedisGeneric(cfg, false, nil)} func newBaseRedisUnique(cfg *BaseConfig) (baseQueue, error) {	return newBaseRedisGeneric(cfg, true, nil)} func (q *baseRedis) prefixedName(name string) string {	return q.prefix + name} func (q *baseRedis) PushItem(ctx context.Context, data []byte) error {	return backoffErr(ctx, backoffBegin, backoffUpper, time.After(pushBlockTime), func() (retry bool, err error) {		q.mu.Lock()		defer q.mu.Unlock() 		cnt, err := q.client.LLen(ctx, q.prefixedName(q.cfg.QueueFullName)).Result()		if err != nil {			return false, err		}		if int(cnt) >= q.cfg.Length {			return true, nil		} 		if q.isUnique {			added, err := q.client.SAdd(ctx, q.prefixedName(q.cfg.SetFullName), data).Result()			if err != nil {				return false, err			}			if added == 0 {				return false, ErrAlreadyInQueue			}		}		return false, q.client.RPush(ctx, q.prefixedName(q.cfg.QueueFullName), data).Err()	})} func (q *baseRedis) PopItem(ctx context.Context) ([]byte, error) {	return backoffRetErr(ctx, backoffBegin, backoffUpper, infiniteTimerC, func() (retry bool, data []byte, err error) {		q.mu.Lock()		defer q.mu.Unlock() 		data, err = q.client.LPop(ctx, q.prefixedName(q.cfg.QueueFullName)).Bytes()		if err == redis.Nil {			return true, nil, nil		}		if err != nil {			return true, nil, nil		}		if q.isUnique {			// the data has been popped, even if there is any error we can't do anything			_ = q.client.SRem(ctx, q.prefixedName(q.cfg.SetFullName), data).Err()		}		return false, data, err	})} func (q *baseRedis) HasItem(ctx context.Context, data []byte) (bool, error) {	q.mu.Lock()	defer q.mu.Unlock()	if !q.isUnique {		return false, nil	}	return q.client.SIsMember(ctx, q.prefixedName(q.cfg.SetFullName), data).Result()} func (q *baseRedis) Len(ctx context.Context) (int, error) {	q.mu.Lock()	defer q.mu.Unlock()	cnt, err := q.client.LLen(ctx, q.prefixedName(q.cfg.QueueFullName)).Result()	return int(cnt), err} func (q *baseRedis) Close() error {	q.mu.Lock()	defer q.mu.Unlock()	return q.client.Close()} func (q *baseRedis) RemoveAll(ctx context.Context) error {	q.mu.Lock()	defer q.mu.Unlock() 	c1 := q.client.Del(ctx, q.prefixedName(q.cfg.QueueFullName))	// the "set" must be cleared after the "list" because there is no transaction.	// it's better to have duplicate items than losing items.	c2 := q.client.Del(ctx, q.prefixedName(q.cfg.SetFullName))	if c1.Err() != nil {		return c1.Err()	}	if c2.Err() != nil {		return c2.Err()	}	return nil // actually, checking errors doesn't make sense here because the state could be out-of-sync}