Merge branch 'ab_Add_SessionMGRCache' into 'devbranch'

Add: Functionality to call session manager from bls.

Closes MKCLOS/coreosv3/corestudio#315

See merge request !170

cachemdl/cache.go

@@ -18,6 +18,11 @@ var (
 )
 
 // Cacher provides access to underlying cache, make sure all caches implement these methods.
+//
+// The return types of data can be different. Ex. In case of redis cache it is `string`. The caller needs to handle this with the help of Type() method.
+//
+// Ex.
+// (Cacher{}).Type() == TypeRedisCache { // your implementation }
 type Cacher interface {
 	// SET
 	Set(key string, val interface{})
@@ -34,6 +39,8 @@ type Cacher interface {
 
 	// GetItemsCount
 	GetItemsCount() int
+
+	Type() int
 }
 
 // GetCacheInstance returns a cache instance, panics if invalid cache type is provided

cachemdl/cache_redis.go

@@ -23,7 +23,6 @@ import (
 	"corelab.mkcl.org/MKCLOS/coredevelopmentplatform/corepkgv2/loggermdl"
 
 	"github.com/go-redis/redis"
-	"github.com/tidwall/gjson"
 )
 
 const (
@@ -52,8 +51,9 @@ type RedisCache struct {
 	Prefix     string        // this will be used for storing keys for provided project
 }
 
-// Setup -
+// Setup initializes redis cache for application. Must be called only once.
 func (rc *RedisCache) Setup(addr, password, prefix string, db int, exp time.Duration) {
+
 	if rc == nil {
 		rc = new(RedisCache)
 	}
@@ -84,6 +84,7 @@ func (rc *RedisCache) Setup(addr, password, prefix string, db int, exp time.Dura
 		rc.keyStr = contcat(rc.Prefix, keySplitter)
 		rc.addPrefix = true
 	}
+
 }
 
 // Set marshalls provided value and stores against provided key. Errors will be logged to initialized logger.
@@ -135,11 +136,11 @@ func (rc *RedisCache) Get(key string) (interface{}, bool) {
 	// Get returns error if key is not present.
 	val, err := rc.cli.Get(rc.key(key)).Result()
 	if err != nil {
-		loggermdl.LogError("error getting key ", key, " error: ", err)
+		loggermdl.LogError("error getting key", key, "from redis cache with error:", err)
 		return nil, false
 	}
 
-	return gjson.Parse(val).Value(), true
+	return val, true
 }
 
 // Delete -
@@ -202,3 +203,7 @@ func (rc *RedisCache) key(key string) string {
 	}
 	return key
 }
+
+func (rc *RedisCache) Type() int {
+	return TypeRedisCache
+}

cachemdl/cachemdl.go

@@ -19,11 +19,13 @@ type FastCacheHelper struct {
 	MaxEntries int
 }
 
-//Setup create new object of GC
+// Setup initializes fastcache cache for application. Must be called only once.
 func (fastCacheHelper *FastCacheHelper) Setup(maxEntries int, expiration time.Duration, cleanupTime time.Duration) {
+
 	fastCacheHelper.MaxEntries = maxEntries
 	fastCacheHelper.Expiration = expiration
 	fastCacheHelper.FastCache = cache.New(fastCacheHelper.Expiration, fastCacheHelper.CleanupTime)
+
 }
 
 // Get -
@@ -65,3 +67,7 @@ func (fastCacheHelper *FastCacheHelper) Delete(key string) {
 func (fastCacheHelper *FastCacheHelper) GetItemsCount() int {
 	return fastCacheHelper.FastCache.ItemCount()
 }
+
+func (fh *FastCacheHelper) Type() int {
+	return TypeFastCache
+}

sessionmanagermdl/sessionmanager.go

+package sessionmanagermdl
+
+import (
+	"coresls/servers/coresls/app/models"
+	"errors"
+	"time"
+
+	"github.com/tidwall/gjson"
+	"github.com/tidwall/sjson"
+
+	"corelab.mkcl.org/MKCLOS/coredevelopmentplatform/corepkgv2/cachemdl"
+)
+
+// Entry is a data to be stored against a key.
+type Entry struct {
+	Data       gjson.Result `json:"data,omitempty"`
+	Expiration int64        `json:"expiration,omitempty"`
+	ExpiredAT  int64        `json:"expiredAt,omitempty"`
+}
+
+const (
+	// keys for the entry object
+	KEY_DATA       = "data"
+	KEY_EXPIREDAT  = "expiredAt"
+	KEY_EXPIRATION = "expiration"
+)
+
+var store cachemdl.Cacher
+
+var ErrSessionNotFound = errors.New("SESSION_NOT_FOUND")
+var ErrInvalidDataType = errors.New("INVALID_DATA_Type")
+
+// InitSessionManagerCache initializes the cache with provided configuration. Need to provide a cache type to use.
+func InitSessionManagerCache(chacheType int) {
+	cacheConfig := cachemdl.CacheConfig{
+		Type: chacheType,
+		RedisCache: &cachemdl.RedisCache{
+			Addr:   "", // empty takes default redis address 6379
+			DB:     models.RedisDBSessionManager,
+			Prefix: models.ProjectID,
+		},
+		FastCache: &cachemdl.FastCacheHelper{
+			CleanupTime: 60 * time.Minute,
+			MaxEntries:  1000,
+			Expiration:  -1,
+		},
+	}
+
+	store = cachemdl.GetCacheInstance(&cacheConfig)
+}
+
+// NewEntry prepares the object required to store data in session.
+//
+// The `exp` field interprets time in seconds. Ex. For 5 seconds, set `5`
+func NewEntry(val gjson.Result, exp int64) Entry {
+	duration := time.Duration(exp) * time.Second
+	deadLine := time.Now().Add(duration).Unix()
+	return Entry{
+		Data:       val,
+		Expiration: exp,
+		ExpiredAT:  deadLine,
+	}
+}
+
+// NewRedisEntry prepares the entry for redis cache. This is required because redis accepts a byte array.
+func NewRedisEntry(entry Entry) string {
+	var data string
+
+	// the error can be ignored here as we have valid keys and data values
+	data, _ = sjson.Set(data, KEY_DATA, entry.Data.Value())
+	data, _ = sjson.Set(data, KEY_EXPIRATION, entry.Expiration)
+	data, _ = sjson.Set(data, KEY_EXPIREDAT, entry.ExpiredAT)
+
+	return data
+}
+
+// ToObject returns an cache entry as an object. It is better than sjson.Set() as we need to perform gjson.Parse().
+func ToObject(entry Entry) map[string]interface{} {
+	return map[string]interface{}{
+		KEY_DATA:       entry.Data.Value(),
+		KEY_EXPIRATION: entry.Expiration,
+		KEY_EXPIREDAT:  entry.ExpiredAT,
+	}
+}
+
+// Store adds/ updates the entry against the provided key.
+func Store(key string, entry Entry) {
+	duration := time.Duration(entry.Expiration) * time.Second
+
+	// if session manager uses redis cache, the data field (gjson.Result) is saved as is.
+	// This adds irrelevant fields in redis cache and we get them on retrieve operation.
+	// The following operation needs to be performed so that the data is marshaled correctly. Redis only accepts []byte{}.
+	if store.Type() == cachemdl.TypeRedisCache {
+		store.SetWithExpiration(key, NewRedisEntry(entry), duration)
+		return
+	}
+
+	store.SetWithExpiration(key, entry, duration)
+}
+
+// Retrieve returns the entry present against the provided key. If a key is not available or data stored is not of type gjson.Result, a non nil error will be returned
+func Retrieve(key string) (Entry, error) {
+	data, ok := store.Get(key)
+	if !ok {
+		return Entry{}, ErrSessionNotFound
+	}
+
+	switch v := data.(type) {
+	case string: // for result from redis cache
+		res := gjson.Parse(v)
+		return Entry{
+			Data:       res.Get(KEY_DATA),
+			Expiration: res.Get(KEY_EXPIRATION).Int(),
+			ExpiredAT:  res.Get(KEY_EXPIREDAT).Int(),
+		}, nil
+
+	case Entry: // for result from fastcache
+		return v, nil
+
+	default:
+		return Entry{}, ErrInvalidDataType
+	}
+}
+
+// Delete removes the entry from session manager. If the key is not present, error `ErrSessionNotFound` will be thrown. Caller can ignore error if this is acceptable.
+func Delete(key string) error {
+	_, ok := store.Get(key)
+	if !ok {
+		return ErrSessionNotFound
+	}
+
+	store.Delete(key)
+	return nil
+}