/// <summary>
/// Adds the record to the table storage service, or if it already exists
/// updates the last active date and time.
/// </summary>
/// <param name="record">Request record of the entity being added or updated.</param>
private void Set(RequestRecord record)
{
lock (_serviceContext)
{
// Get the entity if it exists.
RequestEntity entity = GetEntityFromContext(record);
if (entity == null)
{
entity = GetEntityFromTable(record);
}
if (entity == null)
{
// Add the new entity to the table storage.
_serviceContext.AddObject(
_tableName,
new RequestEntity(record));
}
else
{
// Update the last active time.
entity.LastActiveDate = record.LastActiveDateAsDateTime;
_serviceContext.UpdateObject(entity);
}
// Commit the changes back to the table service.
_serviceContext.SaveChanges();
}
CheckIfServiceRequired();
}
/// <summary>
/// Removes the device behind the request.
/// </summary>
/// <param name="request">The request from the device.</param>
public void Remove(HttpRequest request)
{
if (_enabled == false)
{
return;
}
RequestRecord record = new RequestRecord(request);
Remove(record);
}
/// <summary>
/// Sets the last active time for the device making the request.
/// </summary>
/// <param name="request">The request from the device.</param>
public void Set(HttpRequest request)
{
if (_enabled == false)
{
return;
}
RequestRecord record = new RequestRecord(request);
Set(record);
}
/// <summary>
/// Returns the entity if present from the current context.
/// </summary>
/// <param name="record">Request record of the entity being sought.</param>
/// <returns>The entity if present in the context.</returns>
private RequestEntity GetEntityFromContext(RequestRecord record)
{
var descripter = _serviceContext.Entities.FirstOrDefault(
i =>
i.State != EntityStates.Deleted &&
((RequestEntity)i.Entity).PartitionKey == record.PartitionKey &&
((RequestEntity)i.Entity).RowKey == record.RowKey);
if (descripter != null)
{
return(descripter.Entity as RequestEntity);
}
return(null);
}
/// <summary>
/// Removes the request device details from the table, and then removes
/// from memory once the table has been updated.
/// </summary>
/// <param name="record">Request record of the entity being removed.</param>
private void Remove(RequestRecord record)
{
lock (_serviceContext)
{
// Get the entity matching the record held in the context.
RequestEntity entity = GetEntityFromContext(record);
if (entity == null)
{
// Get the entity from the table if it exists.
entity = GetEntityFromTable(record);
}
// If the entity has been found remove it from the context and the table.
if (entity != null)
{
_serviceContext.DeleteObject(entity);
_serviceContext.SaveChanges();
}
}
}
/// <summary>
/// Returns the entity if present from the table service. Should only be called after
/// checking the entity is not already present in the context.
/// </summary>
/// <param name="record">Request record of the entity being sought.</param>
/// <returns>The entity if present in the table service.</returns>
private RequestEntity GetEntityFromTable(RequestRecord record)
{
// Create query to return all matching entities for this record.
CloudTableQuery<RequestEntity> query = (from entity
in _serviceContext.CreateQuery<RequestEntity>(_tableName)
where entity.PartitionKey == record.PartitionKey && entity.RowKey == record.RowKey
select entity).AsTableServiceQuery<RequestEntity>();
// Return the first or default entity found.
try
{
return query.Execute().FirstOrDefault();
}
catch (DataServiceQueryException ex)
{
//If an exception occurs checked for a 404 error code meaning the resource was not found.
if (ex.Response.StatusCode == 404)
return null;
throw ex;
}
}
/// <summary>
/// Returns the entity if present from the table service. Should only be called after
/// checking the entity is not already present in the context.
/// </summary>
/// <param name="record">Request record of the entity being sought.</param>
/// <returns>The entity if present in the table service.</returns>
private RequestEntity GetEntityFromTable(RequestRecord record)
{
// Create query to return all matching entities for this record.
CloudTableQuery <RequestEntity> query = (from entity
in _serviceContext.CreateQuery <RequestEntity>(_tableName)
where entity.PartitionKey == record.PartitionKey && entity.RowKey == record.RowKey
select entity).AsTableServiceQuery <RequestEntity>();
// Return the first or default entity found.
try
{
return(query.Execute().FirstOrDefault());
}
catch (DataServiceQueryException ex)
{
//If an exception occurs checked for a 404 error code meaning the resource was not found.
if (ex.Response.StatusCode == 404)
{
return(null);
}
throw ex;
}
}
/// <summary>
/// Determines if the device making the request has been seen by the web site previously.
/// </summary>
/// <param name="request">The request from the device.</param>
/// <returns>True if the device has been seen before, otherwise false.</returns>
public bool IsPresent(HttpRequest request)
{
if (_enabled == false)
{
return(false);
}
RequestRecord record = new RequestRecord(request);
lock (_serviceContext)
{
// Get the entity if it exists.
RequestEntity entity = GetEntityFromContext(record);
if (entity == null)
{
entity = GetEntityFromTable(record);
}
// If the entity isn't null and the last active time is within the timeout period.
return(entity != null &&
entity.LastActiveDate.AddMinutes(_redirectTimeout) >= record.LastActiveDateAsDateTime);
}
}
/// <summary>
/// Constructs an instance of RequestDataModel using the unique
/// request ID of the device as the primary key, and the last
/// date the device related to the request was active.
/// </summary>
internal RequestEntity(RequestRecord record) :
base(record.PartitionKey, record.RowKey)
{
LastActiveDate = record.LastActiveDateAsDateTime;
}
/// <summary>
/// Constructs an instance of RequestDataModel using the unique
/// request ID of the device as the primary key, and the last
/// date the device related to the request was active.
/// </summary>
internal RequestEntity(RequestRecord record) :
base(record.PartitionKey, record.RowKey)
{
LastActiveDate = record.LastActiveDateAsDateTime;
}
/// <summary>
/// Returns the entity if present from the current context.
/// </summary>
/// <param name="record">Request record of the entity being sought.</param>
/// <returns>The entity if present in the context.</returns>
private RequestEntity GetEntityFromContext(RequestRecord record)
{
var descripter = _serviceContext.Entities.FirstOrDefault(
i =>
i.State != EntityStates.Deleted &&
((RequestEntity)i.Entity).PartitionKey == record.PartitionKey &&
((RequestEntity)i.Entity).RowKey == record.RowKey);
if (descripter != null)
return descripter.Entity as RequestEntity;
return null;
}
/// <summary>
/// Removes the device behind the request.
/// </summary>
/// <param name="request">The request from the device.</param>
public void Remove(HttpRequest request)
{
if (_enabled == false)
return;
RequestRecord record = new RequestRecord(request);
Remove(record);
}
/// <summary>
/// Determines if the device making the request has been seen by the web site previously.
/// </summary>
/// <param name="request">The request from the device.</param>
/// <returns>True if the device has been seen before, otherwise false.</returns>
public bool IsPresent(HttpRequest request)
{
if (_enabled == false)
return false;
RequestRecord record = new RequestRecord(request);
lock (_serviceContext)
{
// Get the entity if it exists.
RequestEntity entity = GetEntityFromContext(record);
if (entity == null)
entity = GetEntityFromTable(record);
// If the entity isn't null and the last active time is within the timeout period.
return entity != null &&
entity.LastActiveDate.AddMinutes(_redirectTimeout) >= record.LastActiveDateAsDateTime;
}
}
/// <summary>
/// Adds the record to the table storage service, or if it already exists
/// updates the last active date and time.
/// </summary>
/// <param name="record">Request record of the entity being added or updated.</param>
private void Set(RequestRecord record)
{
lock (_serviceContext)
{
// Get the entity if it exists.
RequestEntity entity = GetEntityFromContext(record);
if (entity == null)
entity = GetEntityFromTable(record);
if (entity == null)
{
// Add the new entity to the table storage.
_serviceContext.AddObject(
_tableName,
new RequestEntity(record));
}
else
{
// Update the last active time.
entity.LastActiveDate = record.LastActiveDateAsDateTime;
_serviceContext.UpdateObject(entity);
}
// Commit the changes back to the table service.
_serviceContext.SaveChanges();
}
CheckIfServiceRequired();
}
/// <summary>
/// Removes the request device details from the table, and then removes
/// from memory once the table has been updated.
/// </summary>
/// <param name="record">Request record of the entity being removed.</param>
private void Remove(RequestRecord record)
{
lock (_serviceContext)
{
// Get the entity matching the record held in the context.
RequestEntity entity = GetEntityFromContext(record);
if (entity == null)
// Get the entity from the table if it exists.
entity = GetEntityFromTable(record);
// If the entity has been found remove it from the context and the table.
if (entity != null)
{
_serviceContext.DeleteObject(entity);
_serviceContext.SaveChanges();
}
}
}
