blob: decb0a43a034f398b60285ccfae5cedaa14ac186 [file] [log] [blame]
/*
* Copyright 2018-present Open Networking Foundation
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* http://www.apache.org/licenses/LICENSE-2.0
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package kvstore
import (
"context"
"errors"
"fmt"
"strings"
"sync"
"time"
"github.com/go-redis/redis/v8"
"github.com/opencord/voltha-lib-go/v7/pkg/log"
)
type RedisClient struct {
redisAPI *redis.Client
keyReservations map[string]time.Duration
watchedChannels sync.Map
writeLock sync.Mutex
keyReservationsLock sync.RWMutex
}
func NewRedisClient(addr string, timeout time.Duration, useSentinel bool) (*RedisClient, error) {
var r *redis.Client
if !useSentinel {
r = redis.NewClient(&redis.Options{Addr: addr})
} else {
// Redis Master-Replicas with Sentinel, sentinel masterSet config
// should be set to sebaRedis
r = redis.NewFailoverClient(&redis.FailoverOptions{
MasterName: "sebaRedis",
SentinelAddrs: []string{addr},
})
}
reservations := make(map[string]time.Duration)
return &RedisClient{redisAPI: r, keyReservations: reservations}, nil
}
func (c *RedisClient) Get(ctx context.Context, key string) (*KVPair, error) {
val, err := c.redisAPI.Get(ctx, key).Result()
valBytes, _ := ToByte(val)
if err != nil {
return nil, nil
}
return NewKVPair(key, valBytes, "", 0, 0), nil
}
func (c *RedisClient) Put(ctx context.Context, key string, value interface{}) error {
// Validate that we can convert value to a string as etcd API expects a string
var val string
var er error
if val, er = ToString(value); er != nil {
return fmt.Errorf("unexpected-type-%T", value)
}
// Check if there is already a lease for this key - if there is then use it, otherwise a PUT will make
// that KV key permanent instead of automatically removing it after a lease expiration
setErr := c.redisAPI.Set(ctx, key, val, 0)
err := setErr.Err()
if err != nil {
switch setErr.Err() {
case context.Canceled:
logger.Warnw(ctx, "context-cancelled", log.Fields{"error": err})
case context.DeadlineExceeded:
logger.Warnw(ctx, "context-deadline-exceeded", log.Fields{"error": err})
default:
logger.Warnw(ctx, "bad-endpoints", log.Fields{"error": err})
}
return err
}
return nil
}
func (c *RedisClient) scanAllKeysWithPrefix(ctx context.Context, key string) ([]string, error) {
var err error
allkeys := []string{}
cont := true
cursor := uint64(0)
matchPrefix := key + "*"
for cont {
// search in the first 10000 entries starting from the point indicated by the cursor
logger.Debugw(ctx, "redis-scan", log.Fields{"matchPrefix": matchPrefix, "cursor": cursor})
var keys []string
keys, cursor, err = c.redisAPI.Scan(context.Background(), cursor, matchPrefix, 10000).Result()
if err != nil {
return nil, err
}
if cursor == 0 {
// all data searched. break the loop
logger.Debugw(ctx, "redis-scan-ended", log.Fields{"matchPrefix": matchPrefix, "cursor": cursor})
cont = false
}
if len(keys) == 0 {
// no matched data found in this cycle. Continue to search
logger.Debugw(ctx, "redis-scan-no-data-found-continue", log.Fields{"matchPrefix": matchPrefix, "cursor": cursor})
continue
}
allkeys = append(allkeys, keys...)
}
return allkeys, nil
}
func (c *RedisClient) List(ctx context.Context, key string) (map[string]*KVPair, error) {
var err error
var keys []string
m := make(map[string]*KVPair)
var values []interface{}
if keys, err = c.scanAllKeysWithPrefix(ctx, key); err != nil {
return nil, err
}
if len(keys) != 0 {
values, err = c.redisAPI.MGet(ctx, keys...).Result()
if err != nil {
return nil, err
}
}
for i, key := range keys {
if valBytes, err := ToByte(values[i]); err == nil {
m[key] = NewKVPair(key, interface{}(valBytes), "", 0, 0)
}
}
return m, nil
}
func (c *RedisClient) Delete(ctx context.Context, key string) error {
// delete the key
if _, err := c.redisAPI.Del(ctx, key).Result(); err != nil {
logger.Errorw(ctx, "failed-to-delete-key", log.Fields{"key": key, "error": err})
return err
}
logger.Debugw(ctx, "key(s)-deleted", log.Fields{"key": key})
return nil
}
func (c *RedisClient) DeleteWithPrefix(ctx context.Context, prefixKey string) error {
var keys []string
var err error
if keys, err = c.scanAllKeysWithPrefix(ctx, prefixKey); err != nil {
return err
}
if len(keys) == 0 {
logger.Warn(ctx, "nothing-to-delete-from-kv", log.Fields{"key": prefixKey})
return nil
}
//call delete for keys
entryCount := int64(0)
start := 0
pageSize := 5000
length := len(keys)
for start < length {
end := start + pageSize
if end >= length {
end = length
}
keysToDelete := keys[start:end]
count := int64(0)
if count, err = c.redisAPI.Del(ctx, keysToDelete...).Result(); err != nil {
logger.Errorw(ctx, "DeleteWithPrefix method failed", log.Fields{"prefixKey": prefixKey, "numOfMatchedKeys": len(keysToDelete), "err": err})
return err
}
entryCount += count
start = end
}
logger.Debugf(ctx, "%d entries matching with the key prefix %s have been deleted successfully", entryCount, prefixKey)
return nil
}
func (c *RedisClient) Reserve(ctx context.Context, key string, value interface{}, ttl time.Duration) (interface{}, error) {
var val string
var er error
if val, er = ToString(value); er != nil {
return nil, fmt.Errorf("unexpected-type%T", value)
}
// SetNX -- Only set the key if it does not already exist.
c.redisAPI.SetNX(ctx, key, value, ttl)
// Check if set is successful
redisVal := c.redisAPI.Get(ctx, key).Val()
if redisVal == "" {
println("NULL")
return nil, nil
}
if val == redisVal {
// set is successful, return new reservation value
c.keyReservationsLock.Lock()
c.keyReservations[key] = ttl
c.keyReservationsLock.Unlock()
bytes, _ := ToByte(val)
return bytes, nil
} else {
// set is not successful, return existing reservation value
bytes, _ := ToByte(redisVal)
return bytes, nil
}
}
func (c *RedisClient) ReleaseReservation(ctx context.Context, key string) error {
redisVal := c.redisAPI.Get(ctx, key).Val()
if redisVal == "" {
return nil
}
// Override SetNX value with no TTL
_, err := c.redisAPI.Set(ctx, key, redisVal, 0).Result()
if err != nil {
delete(c.keyReservations, key)
} else {
return err
}
return nil
}
func (c *RedisClient) ReleaseAllReservations(ctx context.Context) error {
c.writeLock.Lock()
defer c.writeLock.Unlock()
for key := range c.keyReservations {
err := c.ReleaseReservation(ctx, key)
if err != nil {
logger.Errorw(ctx, "cannot-release-reservation", log.Fields{"key": key, "error": err})
return err
}
}
return nil
}
func (c *RedisClient) RenewReservation(ctx context.Context, key string) error {
c.writeLock.Lock()
defer c.writeLock.Unlock()
// Verify the key was reserved
ttl, ok := c.keyReservations[key]
if !ok {
return errors.New("key-not-reserved. Key not found")
}
redisVal := c.redisAPI.Get(ctx, key).Val()
if redisVal != "" {
c.redisAPI.Set(ctx, key, redisVal, ttl)
}
return nil
}
func (c *RedisClient) listenForKeyChange(ctx context.Context, redisCh <-chan *redis.Message, ch chan<- *Event, cancel context.CancelFunc) {
logger.Debug(ctx, "start-listening-on-channel ...")
defer cancel()
defer close(ch)
for msg := range redisCh {
words := strings.Split(msg.Channel, ":")
key := words[1]
msgType := getMessageType(msg.Payload)
var valBytes []byte
if msgType == PUT {
ev, _ := c.Get(ctx, key)
valBytes, _ = ToByte(ev.Value)
}
ch <- NewEvent(getMessageType(msg.Payload), []byte(key), valBytes, 0)
}
logger.Debug(ctx, "stop-listening-on-channel ...")
}
func getMessageType(msg string) int {
isPut := strings.HasSuffix(msg, "set")
isDel := strings.HasSuffix(msg, "del")
if isPut {
return PUT
} else if isDel {
return DELETE
} else {
return UNKNOWN
}
}
func (c *RedisClient) addChannelMap(key string, channelMap map[chan *Event]*redis.PubSub) []map[chan *Event]*redis.PubSub {
var channels interface{}
var exists bool
if channels, exists = c.watchedChannels.Load(key); exists {
channels = append(channels.([]map[chan *Event]*redis.PubSub), channelMap)
} else {
channels = []map[chan *Event]*redis.PubSub{channelMap}
}
c.watchedChannels.Store(key, channels)
return channels.([]map[chan *Event]*redis.PubSub)
}
func (c *RedisClient) removeChannelMap(key string, pos int) []map[chan *Event]*redis.PubSub {
var channels interface{}
var exists bool
if channels, exists = c.watchedChannels.Load(key); exists {
channels = append(channels.([]map[chan *Event]*redis.PubSub)[:pos], channels.([]map[chan *Event]*redis.PubSub)[pos+1:]...)
c.watchedChannels.Store(key, channels)
}
return channels.([]map[chan *Event]*redis.PubSub)
}
func (c *RedisClient) getChannelMaps(key string) ([]map[chan *Event]*redis.PubSub, bool) {
var channels interface{}
var exists bool
channels, exists = c.watchedChannels.Load(key)
if channels == nil {
return nil, exists
}
return channels.([]map[chan *Event]*redis.PubSub), exists
}
func (c *RedisClient) Watch(ctx context.Context, key string, withPrefix bool) chan *Event {
ctx, cancel := context.WithCancel(ctx)
var subscribePath string
subscribePath = "__key*__:" + key
if withPrefix {
subscribePath += "*"
}
pubsub := c.redisAPI.PSubscribe(ctx, subscribePath)
redisCh := pubsub.Channel()
// Create new channel
ch := make(chan *Event, maxClientChannelBufferSize)
// Keep track of the created channels so they can be closed when required
channelMap := make(map[chan *Event]*redis.PubSub)
channelMap[ch] = pubsub
channelMaps := c.addChannelMap(key, channelMap)
logger.Debugw(ctx, "watched-channels", log.Fields{"len": len(channelMaps)})
// Launch a go routine to listen for updates
go c.listenForKeyChange(ctx, redisCh, ch, cancel)
return ch
}
func (c *RedisClient) CloseWatch(ctx context.Context, key string, ch chan *Event) {
// Get the array of channels mapping
var watchedChannels []map[chan *Event]*redis.PubSub
var ok bool
if watchedChannels, ok = c.getChannelMaps(key); !ok {
logger.Warnw(ctx, "key-has-no-watched-channels", log.Fields{"key": key})
return
}
// Look for the channels
var pos = -1
for i, chMap := range watchedChannels {
if t, ok := chMap[ch]; ok {
logger.Debug(ctx, "channel-found")
// Close the Redis watcher before the client channel. This should close the etcd channel as well
if err := t.Close(); err != nil {
logger.Errorw(ctx, "watcher-cannot-be-closed", log.Fields{"key": key, "error": err})
}
pos = i
break
}
}
channelMaps, _ := c.getChannelMaps(key)
// Remove that entry if present
if pos >= 0 {
channelMaps = c.removeChannelMap(key, pos)
}
logger.Infow(ctx, "watcher-channel-exiting", log.Fields{"key": key, "channel": channelMaps})
}
func (c *RedisClient) AcquireLock(ctx context.Context, lockName string, timeout time.Duration) error {
return nil
}
func (c *RedisClient) ReleaseLock(lockName string) error {
return nil
}
func (c *RedisClient) IsConnectionUp(ctx context.Context) bool {
if _, err := c.redisAPI.Set(ctx, "connection-check", "1", 0).Result(); err != nil {
return false
}
return true
}
func (c *RedisClient) Close(ctx context.Context) {
if err := c.redisAPI.Close(); err != nil {
logger.Errorw(ctx, "error-closing-client", log.Fields{"error": err})
}
}