/// <summary>
/// Inserts instance of an entity in the cache. Any exisiting entity will be overwritten in the cache.
/// Entity should be a part of the database context or else the method will throw an exception.
/// </summary>
/// <param name="entity">Instance of the entity to be inserted.</param>
/// <param name="cacheKey">cache key that was used to insert the entity.</param>
/// <param name="options">Caching options to be used while storing the entity. Note that some of the options
/// might be overridden such as StoreAs option will always be <see cref="StoreAs.SeperateEntities"/>.</param>
public void Insert(object entity, out string cacheKey, CachingOptions options)
{
Logger.Log(
"Inserting entity '" + entity + "' with options " + options.ToLog() + "",
Microsoft.Extensions.Logging.LogLevel.Trace
);
if (IsValidEntity(entity))
{
NCacheWrapper nCacheWrapper = QueryCacheManager.Cache;
// Generate key using the key generator from NCacheWrapper
cacheKey = nCacheWrapper.DefaultKeyGen.GetKey(CurrentContext, entity);
//
// Items are stored as separate entities in this API because only separate APIs can make it
// to this section of code. List or other similar data structures will fail on IsValidEntity
// so only individual entities will make it to here.
//
nCacheWrapper.Set(cacheKey, entity, options, null, StoreAs.SeperateEntities);
return;
}
else
{
throw new Exception("Entity type and context do not match");
}
}
internal static bool IsSeperateStorageEligible <T>(IQueryable <T> query, CachingOptions options)
{
Logger.Log(
"IsSeparateStorageEligible with " + query.ToString() + " and " + options.ToLog() + "?",
Microsoft.Extensions.Logging.LogLevel.Trace
);
IEntityType entityType = query.GetDbContext().Model.FindEntityType(query.ElementType.FullName);
// Full Projection
if (entityType != null)
{
// If User specified key based caching
if (options.StoreAs == StoreAs.SeperateEntities)
{
if (entityType.FindPrimaryKey() == null)
{
return(false);
}
else
{
return(true);
}
}
else
{
return(false);
}
}
else
{
return(false);
}
}
internal static bool CanDirectPkFetch <T>(IQueryable <T> query, CachingOptions options, out string directKey)
{
Logger.Log(
"CanDirectPkFetch with " + query.ToString() + " and " + options.ToLog(),
Microsoft.Extensions.Logging.LogLevel.Trace
);
directKey = null;
IEntityType entityType = query.GetDbContext().Model.FindEntityType(query.ElementType.FullName);
// Full Projection
if (entityType != null)
{
IKey key = entityType.FindPrimaryKey();
List <IProperty> primaryKeys = key.Properties.ToList();
Dictionary <IProperty, object> pks = new Dictionary <IProperty, object>();
foreach (IProperty pk in primaryKeys)
{
pks.Add(pk, null);
}
List <Expression> queryCriteria = ExtensionMethods.GetQueryCriteriaExp(query.Expression);
if (queryCriteria.Count == 0)
{
return(false);
}
// Verify Entity has PK and query criteria has PK with Equality only
foreach (Expression exp in queryCriteria)
{
if (!IsExpressionPkEquality(exp, pks))
{
return(false);
}
}
// Create Instance then get key
object instance = Activator.CreateInstance(query.ElementType);
foreach (var pk in pks)
{
instance.GetType().GetProperty(pk.Key.Name).SetValue(instance, pk.Value);
}
// Finally get key
directKey = QueryCacheManager.Cache.DefaultKeyGen.GetKey(query.GetDbContext(), instance);
return(true);
}
else
{
return(false);
}
}
internal static List <TItem> Set <TItem>(this NCacheWrapper cache, object key, Dictionary <string, TItem> value, CachingOptions options, Alachisoft.NCache.Runtime.Dependencies.CacheDependency dbDependency, StoreAs storingAs)
{
Logger.Log(
"About to set values with options " + options.ToLog() + ", DbDependency '" + dbDependency + "' and StoringAs '" + storingAs + "'.",
Microsoft.Extensions.Logging.LogLevel.Trace
);
// Add entities if stroing as seperateEntities
if (storingAs == StoreAs.SeperateEntities)
{
Logger.Log("Values are about to be set as separate entities.", Microsoft.Extensions.Logging.LogLevel.Trace);
cache.Set(value.Keys.ToArray(), value.Values.ToArray(), options, dbDependency, storingAs);
}
// from here onwards is the enumerator logic and now it is being done in "else" after we have moved to tags based result set regeneration
else
{
Logger.Log("Values are about to be set as collection.", Microsoft.Extensions.Logging.LogLevel.Trace);
// Add query enumerator
CacheEntry entry = cache.CreateEntry(key);
// Setting options
if (options != null)
{
entry.SetOptions(options);
}
// Setting Value
if (storingAs == StoreAs.Collection)
{
entry.Value = value.Values.ToList();
}
// Mind that this is not the user specified option but the end storing methodology
entry.StoredAs = storingAs;
// Set dependencies in the entry
var aggregateDependency = new AggregateCacheDependency();
if (dbDependency != null)
{
aggregateDependency.Add(dbDependency);
}
entry.Dependencies = aggregateDependency;
cache.Set(key, entry, options, dbDependency, storingAs);
}
return(value.Values.ToList());
}
// Main implementation
private static IEnumerable<T> FromCacheImplementation<T>(CachingMethod cachingMethod, IQueryable<T> query, out string cacheKey, CachingOptions options) where T : class
{
Logger.Log(
"Performing " + cachingMethod + " for " + query.ToString() + " with options " + options.ToLog() + ".", LogLevel.Trace
);
// Create NCache entry options
CachingOptions optionsCloned = (CachingOptions)options.Clone();
cacheKey = null;
string queryStoreKey = null;
if (cachingMethod != CachingMethod.LoadIntoCache)
{
// Verify if query can be fetched seperately
string pkCacheKey;
if (QueryHelper.CanDirectPkFetch(query, optionsCloned, out pkCacheKey))
{
object pkItem;
if (QueryCacheManager.Cache.TryGetValue(pkCacheKey, out pkItem))
{
List<T> resultSetPk = new List<T>();
List<T> resultSetPkTracked = new List<T>();
var stateManagerPk = query.GetStateManager();
resultSetPk.Add((T)pkItem);
foreach (var entity in resultSetPk)
{
resultSetPkTracked.Add(((StateManager)stateManagerPk).GetRefValue(entity));
}
return resultSetPkTracked;
}
}
}
bool cacheHit = false;
IDictionary cacheResult = null;
queryStoreKey = QueryCacheManager.GetQueryCacheKey(query, optionsCloned.QueryIdentifier);
if (optionsCloned.StoreAs == StoreAs.Collection || optionsCloned.QueryIdentifier == null)
{
if (optionsCloned.StoreAs == StoreAs.Collection)
cacheKey = queryStoreKey;
if (optionsCloned.QueryIdentifier == null)
optionsCloned.QueryIdentifier = queryStoreKey;
}
// Check in cache
if (cachingMethod != CachingMethod.LoadIntoCache)
{
cacheHit = QueryCacheManager.Cache.GetByKey(queryStoreKey, out cacheResult);
}
// If not found in cache go for db
if (!cacheHit)
{
var enumerableSet = query.AsEnumerable<T>();
CacheDependency dbDependency = null;
if (optionsCloned.CreateDbDependency)
{
RelationalQueryContext queryContext = null;
IRelationalCommand command = query.CreateCommand(out queryContext);
string connectionString = queryContext.Connection.ConnectionString;
dbDependency = GetDependency(NCacheConfiguration.DatabaseType, command.CommandText, connectionString);
}
return new NCacheEnumerable<T>(queryStoreKey, query, enumerableSet, optionsCloned, dbDependency);
}
// data is found in cache return result set
else
{
// Assume its a collection
if (cacheResult.Count == 1)
{
foreach (var item in cacheResult.Values)
{
CacheEntry entry = item as CacheEntry;
if (entry != null)
{
// Confirmed stored as collection just return the value after casting
IEnumerable<T> resultSetC = (IEnumerable<T>)entry.Value;
// [Umer] i know this tracking is costly but there is no other solution
var resultSetCTracked = new List<T>();
var stateManagerC = query.GetStateManager();
foreach (var entity in resultSetC)
{
resultSetCTracked.Add(((StateManager)stateManagerC).GetRefValue(entity));
}
return resultSetCTracked;
}
break;
}
}
var resultSetSE = cacheResult.Values.Cast<T>();
// [Umer] i know this tracking is costly but there is no other solution
var resultSetSETracked = new List<T>();
var stateManagerSE = query.GetStateManager();
foreach (var entity in resultSetSE)
{
resultSetSETracked.Add(((StateManager)stateManagerSE).GetRefValue(entity));
}
return resultSetSETracked;
}
}
// Main implementation
private static T FromCacheImplementation <T>(CachingMethod cachingMethod, QueryDeferred <T> query, out string cacheKey, CachingOptions options)
{
Logger.Log(
"Performing " + cachingMethod + " for " + query.ToString() + " with options " + options.ToLog() + ".",
Microsoft.Extensions.Logging.LogLevel.Trace
);
options = (CachingOptions)options.Clone();
// Always store as collection
options.StoreAs = StoreAs.Collection;
bool cacheHit = false;
IDictionary cacheResult = default(Hashtable);
cacheKey = QueryCacheManager.GetQueryCacheKey(query.Query, options.QueryIdentifier);
// If user has specified tag, leave it as it is
// Otherwise overwrite it with 'cacheKey'
options.QueryIdentifier = options.QueryIdentifier ?? cacheKey;
/* NOTE: If user stored result with a tag and is trying to query
* it without the tag, it's a different query so don't
* worry about that.
*/
// Get result into 'cacheResult' hashtable if it exists
if (cachingMethod == CachingMethod.FromCache)
{
// Get by the tag (more reliable)
cacheHit = QueryCacheManager.Cache.GetByKey(options.QueryIdentifier, out cacheResult);
}
// If result wasn't found OR result was meant to be stored fresh
if (cachingMethod == CachingMethod.LoadIntoCache || !cacheHit)
{
CacheDependency dbDependency = null;
if (options.CreateDbDependency)
{
IRelationalCommand command = query.Query.CreateCommand(out RelationalQueryContext queryContext);
string connectionString = queryContext.Connection.ConnectionString;
dbDependency = GetDependency(NCacheConfiguration.DatabaseType, command.CommandText, connectionString);
}
object item = query.Execute();
QueryCacheManager.Cache.SetAsCacheEntry(cacheKey, item ?? Null.Value, options, dbDependency);
return(item == null ? default(T) : (T)item);
}
// If result was meant to be fetched instead of stored fresh AND it was found (somewhat)
else
{
object returnVal = default(T);
if (cacheResult != default(Hashtable))
{
returnVal = cacheResult.Values.Cast <CacheEntry>().FirstOrDefault().Value;
}
return(returnVal != null ? (returnVal is Null ? default(T) : (T)returnVal) : default(T));
}
}
