Interface IStateWriter
Provides capabilities to write an engine's state to a store.
Namespace: Reaqtor.QueryEngine
Assembly: Reaqtor.QueryEngine.Interfaces.dll
Syntax
public interface IStateWriter : IDisposableProperties
CheckpointKind
The checkpoint kind.
- For a full checkpoint, all items will be stored.
- For a differential update, only items that have been modified since the last checkpoint will be stored.
Declaration
CheckpointKind CheckpointKind { get; }Property Value
| Type | Description |
|---|---|
| CheckpointKind |
Methods
CommitAsync(CancellationToken, IProgress<Int32>)
Commits the transaction.
Declaration
Task CommitAsync(CancellationToken token, IProgress<int> progress)Parameters
| Type | Name | Description |
|---|---|---|
| System.Threading.CancellationToken | token | Cancellation token to observe cancellation requests. |
| System.IProgress<System.Int32> | progress | (Optional) Progress indicator reporting progress percentages. |
Returns
| Type | Description |
|---|---|
| System.Threading.Tasks.Task | Task to observe the eventual completion of the commit operation. |
Remarks
Prior to calling this method, all item writer streams should be disposed.
DeleteItem(String, String)
Delete the item with the specified category and key from the store.
Declaration
void DeleteItem(string category, string key)Parameters
| Type | Name | Description |
|---|---|---|
| System.String | category | The category of the item to delete. |
| System.String | key | The key of the item to delete. |
Remarks
Notes for implementers:
- If the specified item does not exist, no exception should be thrown. All error reporting should be deferred until the call to CommitAsync(CancellationToken, IProgress<Int32>).
- The deletion of the item should not be committed until a CommitAsync(CancellationToken, IProgress<Int32>) operation has been requested.
GetItemWriter(String, String)
Gets a writable stream to store the state for the item with the specified category and key.
Declaration
Stream GetItemWriter(string category, string key)Parameters
| Type | Name | Description |
|---|---|---|
| System.String | category | The category of the item to obtain a stream for. |
| System.String | key | The key of the item to obtain a stream for. |
Returns
| Type | Description |
|---|---|
| System.IO.Stream | Stream used to store the state for the specified item. |
Remarks
Notes for implementers:
- The returned stream should not contain existing item content. Callers should expect a fresh stream to write to regardless of whether the requested item exists.
- Writes to the returned stream should not be committed until a CommitAsync(CancellationToken, IProgress<Int32>) operation has been requested.
Rollback()
Discards all changes in the transaction.
Declaration
void Rollback()