Class NonblockActionRenderer<T>

Decorates a IActionRenderer<T> instance and lets all rendering events be non-blocking.

Every method call on the renderer will immediately return and the rendering will be performed in a background thread. Note that the order of render events is still guaranteed. In other words, a later event never arrives before events earlier than it.

Inheritance
Object
NonblockRenderer<T>
NonblockActionRenderer<T>
Inherited Members
Namespace: Libplanet.Blockchain.Renderers
Assembly: Libplanet.dll
Syntax
public class NonblockActionRenderer<T> : NonblockRenderer<T>, IDisposable, IActionRenderer<T>, IRenderer<T> where T : IAction, new()
Type Parameters
Name Description
T

An IAction type. It should match to BlockChain<T>'s type parameter.
Remarks

As rendering events become performed in a background thread instead of the main thread, some graphics/UI drawings might be disallowed. In such case, communicate with the main thread through producer/consumer channels.

Examples
IActionRenderer<ExampleAction> actionRenderer = new SomeActionRenderer();
// Wraps the actionRenderer with NonblockActionRenderer; the SomeActionRenderer instance
// becomes to receive event messages in NonblockActionRenderer's backround thread:
actionRenderer = new NonblockActionRenderer<ExampleAction>(
   actionRenderer,
   queue: 1024,
   fullFallback: droppedEvent => ShowError("Too many rendering events in a short time."));
/// ...
// Should be disposed when no longer needed:
actionRenderer.Dispose();

Constructors

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NonblockActionRenderer(IActionRenderer<T>, Int32, NonblockRenderer<T>.FullFallback)

Creates a new instance of NonblockActionRenderer<T> decorating the given renderer instance.

Declaration
public NonblockActionRenderer(IActionRenderer<T> renderer, int queueSize, NonblockRenderer<T>.FullFallback fullFallback)
Parameters
Type Name Description
IActionRenderer<T> renderer

The renderer to decorate which has the actual implementations and receives events in a background thread.
Int32 queueSize

The size of the internal event queue.
NonblockRenderer.FullFallback<> fullFallback

Specifies the custom behavior when the internal event queue is full so that no more event can be added.
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NonblockActionRenderer(IActionRenderer<T>, Int32, NonblockRenderer<T>.FullMode)

Creates a new instance of NonblockActionRenderer<T> decorating the given renderer instance.

Declaration
public NonblockActionRenderer(IActionRenderer<T> renderer, int queueSize, NonblockRenderer<T>.FullMode fullMode)
Parameters
Type Name Description
IActionRenderer<T> renderer

The renderer to decorate which has the actual implementations and receives events in a background thread.
Int32 queueSize

The size of the internal event queue.
NonblockRenderer.FullMode<> fullMode

Specifies the behavior when the internal event queue is full so that no more event can be added.

Properties

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ActionRenderer

The inner action renderer which has the actual implementations and receives events.

Declaration
public IActionRenderer<T> ActionRenderer { get; }
Property Value
Type Description
IActionRenderer<T>

Methods

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RenderAction(IAction, IActionContext, IAccountStateDelta)

Does things that should be done right after an action is executed and applied to the blockchain.

Declaration
public void RenderAction(IAction action, IActionContext context, IAccountStateDelta nextStates)
Parameters
Type Name Description
IAction action

An executed action.
IActionContext context

The equivalent context object to an object passed to the action's Execute(IActionContext) method. That means PreviousStates are the states right before this action executed. For the states after this action executed, use the nextStates argument instead.
IAccountStateDelta nextStates

The states right after this action executed, which means it is equivalent to the states action's Execute(IActionContext) method returned.
Remarks

It is guaranteed to be called only once for an action, and only after applied to the blockchain, unless an exception is thrown during executing the action (in that case RenderActionError(IAction, IActionContext, Exception) is called instead) or once the action has been unrendered.

Also note that this method is invoked after RenderBlock(Block<T>, Block<T>) method is called (where its second parameter newTip contains a transaction the action belongs to).

The reason why the parameter action takes IAction instead of T is because it can take block actions (BlockAction) besides transaction actions (Actions).

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RenderActionError(IAction, IActionContext, Exception)

Does the similar things to RenderAction(IAction, IActionContext, IAccountStateDelta), except that this method is invoked when action has terminated with an exception.

Declaration
public void RenderActionError(IAction action, IActionContext context, Exception exception)
Parameters
Type Name Description
IAction action

An action which threw an exception during execution.
IActionContext context

The equivalent context object to an object passed to the action's Execute(IActionContext) method. That means PreviousStates are the states right before this action executed.
Exception exception

The exception thrown during executing the action.
Remarks

Also note that this method is invoked after RenderBlock(Block<T>, Block<T>) method is called (where its second parameter newTip contains a transaction the action belongs to).

The reason why the parameter action takes IAction instead of T is because it can take block actions (BlockAction) besides transaction actions (Actions).

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RenderBlockEnd(Block<T>, Block<T>)

Does things that should be done right all actions in a new Block<T> are rendered.

Declaration
public void RenderBlockEnd(Block<T> oldTip, Block<T> newTip)
Parameters
Type Name Description
Block<T> oldTip

The previous Tip.
Block<T> newTip

The current Tip.
Remarks

It is guaranteed to be called only once for a block.

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UnrenderAction(IAction, IActionContext, IAccountStateDelta)

Does things that should be undone right after the given action is invalidated (mostly due to reorg, i.e., a block which the action has belonged to becomes considered stale).

This method takes the equivalent arguments to RenderAction(IAction, IActionContext, IAccountStateDelta) method.

Declaration
public void UnrenderAction(IAction action, IActionContext context, IAccountStateDelta nextStates)
Parameters
Type Name Description
IAction action

A stale action.
IActionContext context

The equivalent context object to an object passed to the action's Execute(IActionContext) method. That means PreviousStates are the states right before this action executed. For the states after this action executed, use the nextStates argument instead.
IAccountStateDelta nextStates

The states right after this action executed, which means it is equivalent to the states action's Execute(IActionContext) method returned.
Remarks

As a rule of thumb, this should be the inverse of RenderAction(IAction, IActionContext, IAccountStateDelta) method with redrawing the graphics on the display at the finish.

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UnrenderActionError(IAction, IActionContext, Exception)

Does the similar things to UnrenderAction(IAction, IActionContext, IAccountStateDelta), except that this method is invoked when action has terminated with an exception.

This method takes the equivalent arguments to RenderActionError(IAction, IActionContext, Exception) method.

Declaration
public void UnrenderActionError(IAction action, IActionContext context, Exception exception)
Parameters
Type Name Description
IAction action

An action which threw an exception during execution.
IActionContext context

The equivalent context object to an object passed to the action's Execute(IActionContext) method. That means PreviousStates are the states right before this action executed.
Exception exception

The exception thrown during executing the action.
Remarks

The reason why the parameter action takes IAction instead of T is because it can take block actions (BlockAction) besides transaction actions (Actions).

Implements