Class TaskRunnerBase

The base class for processing and executing tasks on either a server process or the client itself

Inheritance
object
TaskRunnerBase
ClientTaskRunner
ServerTaskRunner
Implements
Inherited Members
Namespace: LemonEdge.API.Core.Tasks
Assembly: LemonEdge.API.dll
Syntax
public abstract class TaskRunnerBase : IDisposable, ITaskRunner, IProcessor

Constructors

TaskRunnerBase(IServerTask, IEntityUpdater, IReadOnlyCache, UserInfo, BusyProgressReporter, IServiceContext, CancellationTokenSource)

Creates a new instance of a Task Runner

Declaration
protected TaskRunnerBase(IServerTask task, IEntityUpdater updater, IReadOnlyCache cache, UserInfo user, BusyProgressReporter reporter, IServiceContext services, CancellationTokenSource cancelSource)
Parameters
Type Name Description
IServerTask task

The instance of the task to be processed.
IEntityUpdater updater

A context to use by default for processing this task, thought the task can create its own contexts if required.
IReadOnlyCache cache

A local context cache
UserInfo user

The user this task should be processed under
BusyProgressReporter reporter

A class for logging and/or reporting progress of the task back to the client
IServiceContext services

The services demanded from the IServiceProvider.
CancellationTokenSource cancelSource

Properties

Cache

A local cache for performance

Declaration
public IReadOnlyCache Cache { get; }
Property Value
Type Description
IReadOnlyCache

CancelTokenSource

The cancellation token for cancelling the running task.

The task process itself must check and respond to this

Declaration
public CancellationTokenSource CancelTokenSource { get; }
Property Value
Type Description
CancellationTokenSource

FailedException

If the processing of this task failed through an exception being thrown, this holds the failed exception

Declaration
public Exception FailedException { get; }
Property Value
Type Description
Exception

Processor

The processor responsible for processing the Task

Declaration
public ITaskProcessor Processor { get; }
Property Value
Type Description
ITaskProcessor

Reporter

A reporter to provide feedback to a log, or client depending on the context the process is running under

Declaration
public BusyProgressReporter Reporter { get; set; }
Property Value
Type Description
BusyProgressReporter

RunningOnServer

Indicates if this task runner is running on a service directly connected to the database, or through a client

Declaration
protected abstract bool RunningOnServer { get; }
Property Value
Type Description
bool

Services

Provides the IServiceContext giving access to core LemonEdge components.

Declaration
public IServiceContext Services { get; }
Property Value
Type Description
IServiceContext

Status

The current status of the task

Declaration
public ServerTaskStatusEnum Status { get; }
Property Value
Type Description
ServerTaskStatusEnum

Task

The current task being processed by this task runner

Declaration
public IServerTask Task { get; }
Property Value
Type Description
IServerTask

TaskData

The current task data being processed by this task runner

Declaration
public IServerTaskData TaskData { get; }
Property Value
Type Description
IServerTaskData

TaskIsVirtual

Indicates the task is a fake task not actually saved in the database, so it should not be updated

By default this is false, indicating the processor is executing real tasks and should update their status, results, etc when complete

When true this is used by the client to create virtual tasks to just immediately process certain tasks, but can not have their status/etc updated when complete as they do not exist
Declaration
protected virtual bool TaskIsVirtual { get; }
Property Value
Type Description
bool

TimeCancelled

If this task has been cancelled this holds the datetime stamp it was cancelled

Declaration
public DateTime? TimeCancelled { get; }
Property Value
Type Description
DateTime?

TimeFinished

Once this task has completed processing this holds the datetime stamp it completed

Declaration
public DateTime? TimeFinished { get; }
Property Value
Type Description
DateTime?

TimeStarted

The datetime stamp the processing of this task was started

Declaration
public DateTime TimeStarted { get; }
Property Value
Type Description
DateTime

Updater

A context to ensure the process can query, load and modify all LemonEdge data

Declaration
public IEntityUpdater Updater { get; }
Property Value
Type Description
IEntityUpdater

User

The current logged in user the process is running under

Declaration
public UserInfo User { get; }
Property Value
Type Description
UserInfo

Methods

AbortThread()

Kills the active thread processing the task if the task was processed from RunOnNewThread()

Declaration
public void AbortThread()

Cancel()

Cancels the processing of this task. The task processor (ITaskProcessor implementation) itself must respond to the cancellation token.

Declaration
public Task Cancel()
Returns
Type Description
Task

CreateTaskHandler()

Creates a new handler for processing the results of a task.

Can be different for client handlers versus server handlers.

Declaration
protected abstract ITaskResultHandler CreateTaskHandler()
Returns
Type Description
ITaskResultHandler

A new handler for processing the results of a task

CreateUpdater()

Creates a new instance of a context for the task to process with. The caller is responsible for disposing it after use.

Declaration
public Task<IEntityUpdater> CreateUpdater()
Returns
Type Description
Task<IEntityUpdater>

A new instance of a context for the task to process with

Dispose()

Declaration
public void Dispose()

Dispose(bool)

Declaration
protected void Dispose(bool disposing)
Parameters
Type Name Description
bool disposing

DisposeManaged()

Declaration
protected virtual void DisposeManaged()

FlushPendingMessages()

Used for cleaning up a task runner before disposing of it.

Flushes all messages against the Reporter

Declaration
public Task FlushPendingMessages()
Returns
Type Description
Task

InternalCreateUpdater()

Creates a new updater context

Declaration
protected abstract Task<IEntityUpdater> InternalCreateUpdater()
Returns
Type Description
Task<IEntityUpdater>

A new updater context

Kill()

If cancel does not cancel the task within enough time, kill can be used to set the task status to cancelled preventing any other processing even if the process completes

Declaration
public Task Kill()
Returns
Type Description
Task

A task indicating the completion of the operation

LogError(Exception, string)

Writes any error processing the system to the log

Can be overridden by implementing classes to log errors elsewhere too

Declaration
protected virtual void LogError(Exception ex, string msg)
Parameters
Type Name Description
Exception ex

The exception being logged
string msg

The message for the exception

Run()

Runs the processing of this Task as a task

Declaration
public Task Run()
Returns
Type Description
Task

A task indicating the completion of processing this Task

RunInternal()

Processes the Task, handling reporting, results, exceptions, and status updates

Declaration
protected virtual Task RunInternal()
Returns
Type Description
Task

A task indicating the completion of the Task

RunOnNewThread()

Runs the processing of this Task on a new thread

Declaration
public void RunOnNewThread()

SetTaskData(IServerTaskData)

Adds the specified task data as the data for this task

Declaration
protected void SetTaskData(IServerTaskData data)
Parameters
Type Name Description
IServerTaskData data

Implements

Extension Methods