protected override async Task <bool> TimeoutCorrectCreateUpdate(PersistenceRequestHolder <K, E> holder)
{
if (holder.Rq.Entity == null || mTransform == null)
{
return(false);
}
var jsonHolder = mTransform.JsonMaker(holder.Rq.Entity);
var alternateHolder = new PersistenceRequestHolder <K, E>(holder.ProfileId, holder.Prq, holder.Prs)
{
Rq = new PersistenceRepositoryHolder <K, E> {
Key = jsonHolder.Key, Timeout = holder.Rq.Timeout
},
Rs = new PersistenceRepositoryHolder <K, E>()
};
if (!(await RetrieveEntity(alternateHolder, ProcessRead)))
{
return(false);
}
holder.Rs.Entity = alternateHolder.Rs.Entity;
holder.Rs.Key = alternateHolder.Rs.Key;
holder.Rs.KeyReference = alternateHolder.Rs.KeyReference;
holder.Rs.ResponseCode = mTransform.Version.SupportsVersioning && jsonHolder.Version.Equals(mTransform.Version.EntityVersionAsString(holder.Rs.Entity))
? alternateHolder.Rs.ResponseCode
: holder.Rs.ResponseCode;
return(holder.Rs.IsSuccess);
}
protected virtual async Task ProcessVersion(PersistenceRequestHolder <K, Tuple <K, string> > holder)
{
IResponseHolder result = null;
if (mCacheManager.IsActive)
{
result = await mCacheManager.VersionRead(mTransform, holder.Rq.Key);
}
if (result == null || !result.IsSuccess)
{
if (mTransform.Version == null)
{
//If we don't set a version maker then how can we return the version.
result = new PersistenceResponseHolder(PersistenceResponse.NotImplemented501)
{
IsSuccess = false
}
}
;
else
{
result = await InternalVersion(holder.Rq.Key, holder);
}
if (mCacheManager.IsActive && !mCacheManager.IsReadOnly && result.IsSuccess)
{
mCacheManager.WriteVersion(mTransform, holder.Rq.Key, result.VersionId);
}
}
ProcessOutputKey(holder.Rq, holder.Rs, result);
}
protected virtual async Task ProcessRead(PersistenceRequestHolder <K, E> holder)
{
IResponseHolder <E> result = null;
if (mCacheManager.IsActive && holder.Rq.Settings.UseCache)
{
result = await mCacheManager.Read(mTransform, holder.Rq.Key);
}
if (result == null || !result.IsSuccess)
{
result = await InternalRead(holder.Rq.Key, holder);
if (mCacheManager.IsActive && !mCacheManager.IsReadOnly && result.IsSuccess)
{
mCacheManager.Write(mTransform, result.Entity);
}
}
else
{
result.IsCacheHit = true;
}
ProcessOutputEntity(holder.Rq.Key, holder.Rq, holder.Rs, result);
}
protected override async Task <bool> TimeoutCorrectDelete(PersistenceRequestHolder <K, Tuple <K, string> > holder)
{
var alternateHolder = new PersistenceRequestHolder <K, E>(holder.ProfileId, holder.Prq, holder.Prs);
alternateHolder.Rq = new PersistenceRepositoryHolder <K, E> {
Key = holder.Rq.Key, KeyReference = holder.Rq.KeyReference, Timeout = holder.Rq.Timeout
};
alternateHolder.Rs = new PersistenceRepositoryHolder <K, E>();
bool byref = alternateHolder.Rq.KeyReference != null && !string.IsNullOrEmpty(alternateHolder.Rq.KeyReference.Item2);
bool result;
if (byref)
{
result = await RetrieveEntity(alternateHolder, ProcessReadByRef);
}
else
{
result = await RetrieveEntity(alternateHolder, ProcessRead);
}
if (result)
{
return(false);
}
// We should have a 404 response code here. If not send back the one we got otherwise send back 200 OK
holder.Rs.Key = alternateHolder.Rs.Key;
holder.Rs.KeyReference = alternateHolder.Rs.KeyReference;
holder.Rs.ResponseCode = alternateHolder.Rs.ResponseCode != 404 ? alternateHolder.Rs.ResponseCode : 200;
return(holder.Rs.IsSuccess);
}
/// <summary>
/// This method logs entities to the event source. This method will try indefinitely
/// as we do not want the Event Source to fail.
/// </summary>
/// <typeparam Name="KT">The key type.</typeparam>
/// <typeparam Name="ET">The entity type.</typeparam>
/// <param name="actionType"></param>
/// <param name="prq"></param>
/// <param name="rq"></param>
/// <param name="rs"></param>
protected async virtual Task LogEventSource <KT, ET>(string actionType, PersistenceRequestHolder <KT, ET> holder)
{
// Only pass through the entity if is of the correct entity type. ET might be an entity or it might be a Tuple<K, string>> in which case pass a null
E entity = typeof(ET) == typeof(E) ? (E)Convert.ChangeType(holder.Rs.Entity, typeof(E)) : default(E);
await LogEventSource(actionType, holder.Prq.Message.OriginatorKey, holder.Rs.Key, entity, holder.Rq.Settings);
}
/// <summary>
/// We don't want to pass the exception details back to the calling party as this may
/// leak sensitive information aboout the application and persistence agent.
/// This method logs the error and assigns it a trackable id and sends that instead to the
/// front end.
/// </summary>
/// <typeparam Name="KT">The key type.</typeparam>
/// <typeparam Name="ET">The entity type.</typeparam>
/// <param Name="action">the entity action.</param>
/// <param Name="prq">The payload request.</param>
/// <param Name="ex">The exception.</param>
/// <param name="rq">The request.</param>
/// <param Name="rs">The response.</param>
protected void LogException <KT, ET>(string action, PersistenceRequestHolder <KT, ET> holder, Exception ex)
{
try
{
var logEvent = new PersistencePayloadLogEvent(holder.Prq, holder.Rq, holder.Rs, LoggingLevel.Info, ex);
Logger.Log(logEvent);
Guid errorId = Guid.NewGuid();
string errMessage = string.Format("Exception tracker {0}/{1}/{2}", action, (holder.Prq != null && holder.Prq.Message != null ? holder.Prq.Message.OriginatorKey : string.Empty), errorId);
holder.Rs.ResponseMessage = errMessage;
if (holder.Rq != null)
{
errMessage += string.Format("/{0}-{1}", holder.Rq.Key, (holder.Rq.Entity == null) ? string.Empty : holder.Rq.Entity.ToString());
}
Logger.LogException(errMessage, ex);
}
catch (Exception)
{
// Do not fail due to an issue logging
}
holder.Rs.ResponseCode = 500;
holder.Rs.ResponseMessage = ex.Message;
}
protected virtual async Task <IResponseHolder> InternalVersion(K key, PersistenceRequestHolder <K, Tuple <K, string> > holder)
{
return(new PersistenceResponseHolder(PersistenceResponse.NotImplemented501)
{
IsSuccess = false
});
}
/// <summary>
/// Retrieves an entity using the supplied read action (read or read by ref) using the persistence retry policy
/// </summary>
/// <param name="rq">Read request</param>
/// <param name="rs">Read response</param>
/// <param name="m">Transmission request message</param>
/// <param name="l">Tranmission response messages</param>
/// <param name="readAction">Read action</param>
/// <returns></returns>
protected virtual async Task <bool> RetrieveEntity(PersistenceRequestHolder <K, E> holder, Func <PersistenceRequestHolder <K, E>, Task> readAction)
{
int numberOfRetries = 0;
int maximumRetries = mPolicy.PersistenceRetryPolicy.GetMaximumRetries(holder.Prq);
while (numberOfRetries < maximumRetries && !holder.Prq.Cancel.IsCancellationRequested)
{
await readAction(holder);
if (holder.Rs.Entity != null || holder.Rs.ResponseCode == 404)
{
return(holder.Rs.Entity != null);
}
await Task.Delay(mPolicy.PersistenceRetryPolicy.GetDelayBetweenRetries(holder.Prq, numberOfRetries));
numberOfRetries++;
}
Collector?.LogMessage(LoggingLevel.Error
, string.Format(
"Unable to retrieve entity after {0} retries, message cancelled({1}) on channel({2}) for request: {3} - response: {4}"
, numberOfRetries
, holder.Prq.Cancel.IsCancellationRequested
, holder.Prq.Message != null ? holder.Prq.Message.ChannelPriority.ToString() : "null"
, holder.Rq
, holder.Rs)
, "DocDb"
);
return(false);
}
/// <summary>
/// Records the specified holder response.
/// </summary>
/// <typeparam name="KT">The key type.</typeparam>
/// <typeparam name="ET">The entity type.</typeparam>
/// <param name="holder">The request holder.</param>
public virtual void Record <KT, ET>(PersistenceRequestHolder <KT, ET> holder)
{
int responseCode = holder.Rs?.ResponseCode ?? 0;
var stats = mResponses.GetOrAdd(responseCode, new ResponseCodeStatistics(responseCode));
stats.Record(holder.Extent, holder.Rs);
}
/// <summary>
/// This is called when the request is retried due to an underlying storage issue.
/// </summary>
/// <typeparam name="KT">The key type.</typeparam>
/// <typeparam name="ET">The entity type.</typeparam>
/// <param name="holder">The request holder.</param>
/// <param name="retryStart">The tick count of the retry point.</param>
protected virtual void ProfileRetry <KT, ET>(PersistenceRequestHolder <KT, ET> holder, int retryStart)
{
mPolicy.ResourceConsumer?.Retry(holder.ProfileId, retryStart, holder.Rs.ShouldRetry ? ResourceRetryReason.Other : ResourceRetryReason.Timeout);
holder.Retry(retryStart);
StatisticsInternal.RetryIncrement();
}
/// <summary>
/// The internal delete command.
/// </summary>
/// <param name="key">The key.</param>
/// <param name="holder">The request holder.</param>
/// <returns></returns>
protected override async Task <IResponseHolder> InternalDelete(K key, PersistenceRequestHolder <K, Tuple <K, string> > holder)
{
if (!Container.Remove(key))
{
return(new PersistenceResponseHolder(PersistenceResponse.NotFound404));
}
return(new PersistenceResponseHolder(PersistenceResponse.Ok200));
}
//Logging
#region Log<KT, ET>...
/// <summary>
///
/// </summary>
/// <typeparam Name="KT">The key type.</typeparam>
/// <typeparam Name="ET">The entity type.</typeparam>
/// <param name="action"></param>
/// <param name="prq"></param>
/// <param name="rq"></param>
/// <param name="rs"></param>
/// <param name="loggingLevel">Logging level</param>
/// <param name="message"></param>
protected void Log <KT, ET>(string action, PersistenceRequestHolder <KT, ET> holder
, LoggingLevel loggingLevel = LoggingLevel.Info, string message = null, string category = null)
{
var logEvent = new PersistencePayloadLogEvent(holder.Prq, holder.Rq, holder.Rs, loggingLevel)
{
Message = message ?? string.Empty, Category = category
};
Logger.Log(logEvent);
}
protected virtual async Task ProcessDeleteByRef(PersistenceRequestHolder <K, Tuple <K, string> > holder)
{
var result = await InternalDeleteByRef(holder.Rq.KeyReference, holder);
if (mCacheManager.IsActive && result.IsSuccess)
{
await mCacheManager.Delete(mTransform, mTransform.KeyDeserializer(result.Id));
}
ProcessOutputKey(holder.Rq, holder.Rs, result);
}
/// <summary>
/// Update
/// </summary>
/// <param name="rq">The request.</param>
/// <param name="rs">The response.</param>
/// <param name="prq">The incoming payload.</param>
/// <param name="prs">The outgoing payload.</param>
protected override async Task <IResponseHolder <E> > InternalUpdate(K key, PersistenceRequestHolder <K, E> holder)
{
var jsonHolder = mTransform.JsonMaker(holder.Rq.Entity);
var result = await mStorage.Update(mStorageIdMaker(jsonHolder.Key)
, jsonHolder.ToBlob()
, contentType : "application/json; charset=utf-8"
, version : jsonHolder.Version, directory : mDirectory);
return(PersistenceResponseFormat(result));
}
protected virtual async Task ProcessDelete(PersistenceRequestHolder <K, Tuple <K, string> > holder)
{
//We presume that the delete will succeed and remove it from the cache before it is processed.
//Worse case this will result in a cache miss.
if (mCacheManager.IsActive)
{
await mCacheManager.Delete(mTransform, holder.Rq.Key);
}
var result = await InternalDelete(holder.Rq.Key, holder);
ProcessOutputKey(holder.Rq, holder.Rs, result);
}
//Requests
#region Create
protected virtual async Task ProcessCreate(PersistenceRequestHolder <K, E> holder)
{
K key = mTransform.KeyMaker(holder.Rq.Entity);
var result = await InternalCreate(key, holder);
if (mCacheManager.IsActive && !mCacheManager.IsReadOnly && result.IsSuccess)
{
mCacheManager.Write(mTransform, result.Entity);
}
ProcessOutputEntity(key, holder.Rq, holder.Rs, result);
}
protected async override Task <IResponseHolder <E> > InternalUpdate(K key, PersistenceRequestHolder <K, E> holder)
{
if (await mCacheManager.Write(mTransform, holder.Rq.Entity))
{
return new PersistenceResponseHolder <E> {
IsSuccess = true, StatusCode = 200, Entity = holder.Rq.Entity
}
}
;
return(new PersistenceResponseHolder <E> {
IsSuccess = false, StatusCode = 409
});
}
protected async override Task <IResponseHolder> InternalDelete(K key, PersistenceRequestHolder <K, Tuple <K, string> > holder)
{
if (await mCacheManager.Delete(mTransform, key))
{
return new PersistenceResponseHolder <E> {
IsSuccess = true, StatusCode = 200
}
}
;
return(new PersistenceResponseHolder <E> {
IsSuccess = false, StatusCode = 404
});
}
/// <summary>
/// This method marks the incoming request as complete.
/// </summary>
/// <typeparam name="KT">The key type.</typeparam>
/// <typeparam name="ET">The entity type.</typeparam>
/// <param name="holder">The request holder.</param>
protected virtual void ProfileEnd <KT, ET>(PersistenceRequestHolder <KT, ET> holder)
{
mPolicy.ResourceConsumer?.End(holder.ProfileId, holder.Start, holder.result ?? ResourceRequestResult.Unknown);
IPersistenceRequestHolder ok;
mRequestsCurrent.TryRemove(holder.ProfileId, out ok);
PersistenceHandler handler;
if (SupportedResolve(holder.Prq.Message.ToServiceMessageHeader(), out handler))
{
handler.Record(holder);
}
}
/// <summary>
/// The internal version command.
/// </summary>
/// <param name="key">The key.</param>
/// <param name="holder">The request holder.</param>
/// <returns></returns>
protected override async Task <IResponseHolder> InternalVersion(K key, PersistenceRequestHolder <K, Tuple <K, string> > holder)
{
E entity;
bool success = Container.TryGetValue(key, out entity);
if (success)
{
JsonHolder <K> jsonHolder = mTransform.JsonMaker(entity);
return(new PersistenceResponseHolder(PersistenceResponse.Ok200, jsonHolder.Json));
}
else
{
return(new PersistenceResponseHolder(PersistenceResponse.NotFound404));
}
}
/// <summary>
/// This is the read implementation.
/// </summary>
/// <param name="key">The key.</param>
/// <param name="holder">The request holder.</param>
/// <returns></returns>
protected override async Task <IResponseHolder <E> > InternalRead(K key, PersistenceRequestHolder <K, E> holder)
{
E entity;
bool success = Container.TryGetValue(key, out entity);
if (success)
{
JsonHolder <K> jsonHolder = mTransform.JsonMaker(entity);
return(new PersistenceResponseHolder <E>(PersistenceResponse.Ok200, jsonHolder.Json, mTransform.PersistenceEntitySerializer.Deserializer(jsonHolder.Json)));
}
else
{
return(new PersistenceResponseHolder <E>(PersistenceResponse.NotFound404));
}
}
/// <summary>
/// This is the create override for the command.
/// </summary>
/// <param name="key">The key.</param>
/// <param name="holder">The entity holder.</param>
/// <returns>Returns the response encapsulated in a PersistenceResponseHolder object.</returns>
protected override async Task <IResponseHolder <E> > InternalCreate(K key, PersistenceRequestHolder <K, E> holder)
{
E entity = holder.Rq.Entity;
int response = EntityPopulate(key, entity);
if (response == 201)
{
JsonHolder <K> jsonHolder = mTransform.JsonMaker(entity);
return(new PersistenceResponseHolder <E>(PersistenceResponse.Created201, jsonHolder.Json, mTransform.PersistenceEntitySerializer.Deserializer(jsonHolder.Json)));
}
else
{
return(new PersistenceResponseHolder <E>(PersistenceResponse.Conflict409));
}
}
/// <summary>
/// This is the entity search.
/// </summary>
/// <param name="holder">The is the entity search data.</param>
/// <returns>This is an async task.</returns>
protected virtual async Task ProcessSearch(PersistenceRequestHolder <SearchRequest, SearchResponse> holder)
{
IResponseHolder <SearchResponse> result = null;
result = await InternalSearch(holder.Rq.Key, holder);
holder.Rs.Entity = result.Entity;
holder.Rs.Key = holder.Rq.Key;
//rs.Settings.VersionId = mTransform.Version?.EntityVersionAsString(rs.Entity);
//rs.KeyReference = new Tuple<string, string>(rs.Key.ToString(), rs.Settings.VersionId);
//holder.Rs.ResponseCode = (int)PersistenceResponse.NotImplemented501;
//holder.Rs.ResponseMessage = "Search is not implemented.";
}
//Profiling
#region ProfileStart/ProfileEnd/ProfileRetry
/// <summary>
/// This method starts the request profile and creates the request holder with the profile id.
/// </summary>
/// <typeparam name="KT">The key type.</typeparam>
/// <typeparam name="ET">The entity type.</typeparam>
/// <param name="prq">The incoming request.</param>
/// <param name="prs">The outgoing response.</param>
/// <returns>Returns the new request holder.</returns>
protected virtual PersistenceRequestHolder <KT, ET> ProfileStart <KT, ET>(TransmissionPayload prq, List <TransmissionPayload> prs)
{
Guid profileId;
if (mPolicy.ResourceConsumer == null)
{
profileId = Guid.NewGuid();
}
else
{
profileId = mPolicy.ResourceConsumer.Start(prq.Message.ToKey(), prq.Id);
}
var holder = new PersistenceRequestHolder <KT, ET>(profileId, prq, prs);
mRequestsCurrent.TryAdd(holder.ProfileId, holder);
return(holder);
}
protected virtual async Task ProcessUpdate(PersistenceRequestHolder <K, E> holder)
{
K key = mTransform.KeyMaker(holder.Rq.Entity);
// Remove from the cache first to ensure no change of ending up with a stale cached item
// if the write to cache fails for any reason
if (mCacheManager.IsActive)
{
mCacheManager.Delete(mTransform, key);
}
var result = await InternalUpdate(key, holder);
if (mCacheManager.IsActive && result.IsSuccess)
{
mCacheManager.Write(mTransform, result.Entity);
}
ProcessOutputEntity(key, holder.Rq, holder.Rs, result);
}
/// <summary>
/// The internal update command.
/// </summary>
/// <param name="key">The key.</param>
/// <param name="holder">The request holder.</param>
/// <returns></returns>
protected override async Task <IResponseHolder <E> > InternalUpdate(K key, PersistenceRequestHolder <K, E> holder)
{
E oldEntity;
bool successExisting = Container.TryGetValue(key, out oldEntity);
if (!successExisting)
{
return(new PersistenceResponseHolder <E>(PersistenceResponse.NotFound404));
}
E newEntity = holder.Rq.Entity;
var ver = mTransform.Version;
if (ver.SupportsOptimisticLocking)
{
if (ver.EntityVersionAsString(oldEntity) != ver.EntityVersionAsString(newEntity))
{
return(new PersistenceResponseHolder <E>(PersistenceResponse.PreconditionFailed412));
}
}
if (ver.SupportsVersioning)
{
ver.EntityVersionUpdate(newEntity);
}
Container.Update(key, newEntity, mTransform.ReferenceMaker(newEntity));
var jsonHolder = mTransform.JsonMaker(newEntity);
return(new PersistenceResponseHolder <E>(PersistenceResponse.Ok200)
{
Content = jsonHolder.Json
, IsSuccess = true
, Entity = newEntity
});
}
protected virtual async Task ProcessVersionByRef(PersistenceRequestHolder <K, Tuple <K, string> > holder)
{
IResponseHolder result = null;
if (mCacheManager.IsActive)
{
result = await mCacheManager.VersionRead(mTransform, holder.Rq.KeyReference);
}
if (result == null || !result.IsSuccess)
{
result = await InternalVersionByRef(holder.Rq.KeyReference, holder);
if (mCacheManager.IsActive && !mCacheManager.IsReadOnly && result.IsSuccess)
{
mCacheManager.WriteReference(mTransform, holder.Rq.KeyReference, holder.Rq.Key, result.VersionId);
}
}
else
{
holder.Rq.Key = mTransform.KeyDeserializer(result.Id); // Pass back the entities actual id in the key field
}
ProcessOutputKey(holder.Rq, holder.Rs, result);
}
/// <summary>
/// The internal search command.
/// </summary>
/// <param name="key">The search request.</param>
/// <param name="holder">The request holder.</param>
/// <returns></returns>
protected async override Task <IResponseHolder <SearchResponse> > InternalSearch(SearchRequest key, PersistenceRequestHolder <SearchRequest, SearchResponse> holder)
{
var query = Container.Values.AsQueryable <E>();
Expression expression = mTransform.SearchTranslator.Build(key);
//Execute Expression on Query
bool success = true; //for the time being since we are not executing any queries
holder.Rs.Entity = new SearchResponse();
List <JObject> jObjects = new List <JObject>();
foreach (var source in query.ToList())
{
jObjects.Add(JObject.FromObject(source));
}
if (success)
{
var resultEntities = query.ToList();
holder.Rs.Entity.Data = jObjects;
return(new PersistenceResponseHolder <SearchResponse>(PersistenceResponse.Ok200, null, holder.Rs.Entity));
}
//holder.Rs.
//key.Select
////Create the expression parameters
//ParameterExpression num1 = Expression.Parameter(typeof(E), "num1");
//ParameterExpression num2 = Expression.Parameter(typeof(E), "num2");
////Create the expression parameters
//ParameterExpression[] parameters = new ParameterExpression[] { num1, num2 };
////Create the expression body
//BinaryExpression body = Expression.Add(num1, num2);
////Expression predicateBody = Expression.OrElse(e1, e2);
////Create the expression
//Expression<Func<int, int, int>> expression = Expression.Lambda<Func<int, int, int>>(body, parameters);
//// Compile the expression
//Func<int, int, int> compiledExpression = expression.Compile();
//// Execute the expression.
//int result = compiledExpression(3, 4);
return(await base.InternalSearch(key, holder));
}
protected async override Task <IResponseHolder <E> > InternalRead(K key, PersistenceRequestHolder <K, E> holder)
{
return(await mCacheManager.Read(mTransform, key));
}
protected async override Task <IResponseHolder> InternalVersionByRef(Tuple <string, string> reference, PersistenceRequestHolder <K, Tuple <K, string> > holder)
{
return(await mCacheManager.VersionRead(mTransform, reference));
}