1 files changed, 162 insertions, 0 deletions
diff --git a/modules/queue/base_redis.go b/modules/queue/base_redis.go
new file mode 100644
index 0000000..62df30f
--- /dev/null
+++ b/modules/queue/base_redis.go
@@ -0,0 +1,162 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package queue
+
+import (
+	"context"
+	"sync"
+	"time"
+
+	"code.gitea.io/gitea/modules/graceful"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/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
+}