Issue indexer queue redis support (#6218)

* add redis queue

* finished indexer redis queue

* add redis vendor

* fix vet

* Update docs/content/doc/advanced/config-cheat-sheet.en-us.md

Co-Authored-By: lunny <xiaolunwen@gmail.com>

* switch to go mod

* Update required changes for new logging func signatures

modules/indexer/issues/queue_redis.go

@@ -0,0 +1,145 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package issues
+
+import (
+	"encoding/json"
+	"errors"
+	"strconv"
+	"strings"
+	"time"
+
+	"code.gitea.io/gitea/modules/log"
+	"github.com/go-redis/redis"
+)
+
+var (
+	_ Queue = &RedisQueue{}
+)
+
+type redisClient interface {
+	RPush(key string, args ...interface{}) *redis.IntCmd
+	LPop(key string) *redis.StringCmd
+	Ping() *redis.StatusCmd
+}
+
+// RedisQueue redis queue
+type RedisQueue struct {
+	client      redisClient
+	queueName   string
+	indexer     Indexer
+	batchNumber int
+}
+
+func parseConnStr(connStr string) (addrs, password string, dbIdx int, err error) {
+	fields := strings.Fields(connStr)
+	for _, f := range fields {
+		items := strings.SplitN(f, "=", 2)
+		if len(items) < 2 {
+			continue
+		}
+		switch strings.ToLower(items[0]) {
+		case "addrs":
+			addrs = items[1]
+		case "password":
+			password = items[1]
+		case "db":
+			dbIdx, err = strconv.Atoi(items[1])
+			if err != nil {
+				return
+			}
+		}
+	}
+	return
+}
+
+// NewRedisQueue creates single redis or cluster redis queue
+func NewRedisQueue(addrs string, password string, dbIdx int, indexer Indexer, batchNumber int) (*RedisQueue, error) {
+	dbs := strings.Split(addrs, ",")
+	var queue = RedisQueue{
+		queueName:   "issue_indexer_queue",
+		indexer:     indexer,
+		batchNumber: batchNumber,
+	}
+	if len(dbs) == 0 {
+		return nil, errors.New("no redis host found")
+	} else if len(dbs) == 1 {
+		queue.client = redis.NewClient(&redis.Options{
+			Addr:     strings.TrimSpace(dbs[0]), // use default Addr
+			Password: password,                  // no password set
+			DB:       dbIdx,                     // use default DB
+		})
+	} else {
+		queue.client = redis.NewClusterClient(&redis.ClusterOptions{
+			Addrs: dbs,
+		})
+	}
+	if err := queue.client.Ping().Err(); err != nil {
+		return nil, err
+	}
+	return &queue, nil
+}
+
+// Run runs the redis queue
+func (r *RedisQueue) Run() error {
+	var i int
+	var datas = make([]*IndexerData, 0, r.batchNumber)
+	for {
+		bs, err := r.client.LPop(r.queueName).Bytes()
+		if err != nil && err != redis.Nil {
+			log.Error("LPop faile: %v", err)
+			time.Sleep(time.Millisecond * 100)
+			continue
+		}
+
+		i++
+		if len(datas) > r.batchNumber || (len(datas) > 0 && i > 3) {
+			r.indexer.Index(datas)
+			datas = make([]*IndexerData, 0, r.batchNumber)
+			i = 0
+		}
+
+		if len(bs) <= 0 {
+			time.Sleep(time.Millisecond * 100)
+			continue
+		}
+
+		var data IndexerData
+		err = json.Unmarshal(bs, &data)
+		if err != nil {
+			log.Error("Unmarshal: %v", err)
+			time.Sleep(time.Millisecond * 100)
+			continue
+		}
+
+		log.Trace("RedisQueue: task found: %#v", data)
+
+		if data.IsDelete {
+			if data.ID > 0 {
+				if err = r.indexer.Delete(data.ID); err != nil {
+					log.Error("indexer.Delete: %v", err)
+				}
+			} else if len(data.IDs) > 0 {
+				if err = r.indexer.Delete(data.IDs...); err != nil {
+					log.Error("indexer.Delete: %v", err)
+				}
+			}
+			time.Sleep(time.Millisecond * 100)
+			continue
+		}
+
+		datas = append(datas, &data)
+		time.Sleep(time.Millisecond * 100)
+	}
+}
+
+// Push implements Queue
+func (r *RedisQueue) Push(data *IndexerData) error {
+	bs, err := json.Marshal(data)
+	if err != nil {
+		return err
+	}
+	return r.client.RPush(r.queueName, bs).Err()
+}