Class AsyncQldbDriver

Represents a factory for accessing a specific ledger within QLDB. This class or QldbDriver should be the main entry points to any interaction with QLDB.

This factory pools sessions and attempts to return unused but available sessions when getting new sessions. The pool does not remove stale sessions until a new session is retrieved. The default pool size is the maximum amount of connections the session client allows set in the . Dispose() should be called when this factory is no longer needed in order to clean up resources, ending all sessions in the pool.

Inheritance

System.Object

AsyncQldbDriver

Implements

IAsyncQldbDriver

System.IDisposable

Inherited Members

System.Object.Equals(System.Object)

System.Object.Equals(System.Object, System.Object)

System.Object.GetHashCode()

System.Object.GetType()

System.Object.MemberwiseClone()

System.Object.ReferenceEquals(System.Object, System.Object)

System.Object.ToString()

Namespace: Amazon.QLDB.Driver

Assembly: Amazon.QLDB.Driver.dll

Syntax

public class AsyncQldbDriver : IAsyncQldbDriver, IDisposable

Methods

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Builder()

Retrieve a builder object for creating a AsyncQldbDriver.

Declaration

public static AsyncQldbDriverBuilder Builder()

Returns

Type	Description
AsyncQldbDriverBuilder	The builder object for creating a AsyncQldbDriver.

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Dispose()

Close this driver and end all sessions in the current pool. No-op if already closed.

Declaration

public void Dispose()

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Execute(Func<AsyncTransactionExecutor, Task>, RetryPolicy, CancellationToken)

Execute the Async Executor lambda against QLDB within a transaction where no result is expected.

Declaration

public async Task Execute(Func<AsyncTransactionExecutor, Task> action, RetryPolicy retryPolicy, CancellationToken cancellationToken = default(CancellationToken))

Parameters

Type	Name	Description
System.Func<AsyncTransactionExecutor, System.Threading.Tasks.Task>	action	The Async Executor lambda with no return value representing the block of code to be executed within the transaction. This cannot have any side effects as it may be invoked multiple times.
RetryPolicy	retryPolicy	A RetryPolicy that overrides the RetryPolicy set when creating the driver. The given retry policy will be used when retrying the transaction.
System.Threading.CancellationToken	cancellationToken	A cancellation token that can be used by other objects or threads to receive notice of cancellation.

Returns

Type	Description
System.Threading.Tasks.Task	No object or value is returned by this method when it completes.

Exceptions

Type	Condition
TransactionAbortedException	Thrown if the Executor lambda calls Abort().
QldbDriverException	Thrown when called on a disposed instance.
Amazon.Runtime.AmazonServiceException	Thrown when there is an error executing against QLDB.

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Execute(Func<AsyncTransactionExecutor, Task>, CancellationToken)

Execute the Async Executor lambda against QLDB within a transaction where no result is expected.

Declaration

public async Task Execute(Func<AsyncTransactionExecutor, Task> action, CancellationToken cancellationToken = default(CancellationToken))

Parameters

Type	Name	Description
System.Func<AsyncTransactionExecutor, System.Threading.Tasks.Task>	action	The Async Executor lambda with no return value representing the block of code to be executed within the transaction. This cannot have any side effects as it may be invoked multiple times.
System.Threading.CancellationToken	cancellationToken	A cancellation token that can be used by other objects or threads to receive notice of cancellation.

Returns

Type	Description
System.Threading.Tasks.Task	No object or value is returned by this method when it completes.

Exceptions

Type	Condition
TransactionAbortedException	Thrown if the Executor lambda calls Abort().
QldbDriverException	Thrown when called on a disposed instance.
Amazon.Runtime.AmazonServiceException	Thrown when there is an error executing against QLDB.

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Execute<T>(Func<AsyncTransactionExecutor, Task<T>>, RetryPolicy, CancellationToken)

Execute the Async Executor lambda against QLDB and retrieve the result within a transaction.

Declaration

public async Task<T> Execute<T>(Func<AsyncTransactionExecutor, Task<T>> func, RetryPolicy retryPolicy, CancellationToken cancellationToken = default(CancellationToken))

Parameters

Type	Name	Description
System.Func<AsyncTransactionExecutor, System.Threading.Tasks.Task<T>>	func	The Async Executor lambda representing the block of code to be executed within the transaction. This cannot have any side effects as it may be invoked multiple times, and the result cannot be trusted until the transaction is committed.
RetryPolicy	retryPolicy	A RetryPolicy that overrides the RetryPolicy set when creating the driver. The given retry policy will be used when retrying the transaction.
System.Threading.CancellationToken	cancellationToken	A cancellation token that can be used by other objects or threads to receive notice of cancellation.

Returns

Type	Description
System.Threading.Tasks.Task<T>	The Task containing return value of executing the executor. Note that if you directly return a IAsyncResult, this will be automatically buffered in memory before the implicit commit to allow reading, as the commit will close any open results. Any other IAsyncResult instances created within the executor block will be invalidated, including if the return value is an object which nests said IAsyncResult instances within it.

Type Parameters

Name	Description
T	The return type.

Exceptions

Type	Condition
TransactionAbortedException	Thrown if the Executor lambda calls Abort().
QldbDriverException	Thrown when called on a disposed instance.
Amazon.Runtime.AmazonServiceException	Thrown when there is an error executing against QLDB.

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Execute<T>(Func<AsyncTransactionExecutor, Task<T>>, CancellationToken)

Execute the Async Executor lambda against QLDB and retrieve the result within a transaction.

Declaration

public async Task<T> Execute<T>(Func<AsyncTransactionExecutor, Task<T>> func, CancellationToken cancellationToken = default(CancellationToken))

Parameters

Type	Name	Description
System.Func<AsyncTransactionExecutor, System.Threading.Tasks.Task<T>>	func	The Async Executor lambda representing the block of code to be executed within the transaction. This cannot have any side effects as it may be invoked multiple times, and the result cannot be trusted until the transaction is committed.
System.Threading.CancellationToken	cancellationToken	A cancellation token that can be used by other objects or threads to receive notice of cancellation.

Returns

Type	Description
System.Threading.Tasks.Task<T>	The Task containing return value of executing the executor. Note that if you directly return a IAsyncResult, this will be automatically buffered in memory before the implicit commit to allow reading, as the commit will close any open results. Any other IAsyncResult instances created within the executor block will be invalidated, including if the return value is an object which nests said IAsyncResult instances within it.

Type Parameters

Name	Description
T	The return type.

Exceptions

Type	Condition
TransactionAbortedException	Thrown if the Executor lambda calls Abort().
QldbDriverException	Thrown when called on a disposed instance.
Amazon.Runtime.AmazonServiceException	Thrown when there is an error executing against QLDB.

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ListTableNames(CancellationToken)

Retrieve the table names that are available within the ledger.

Declaration

public async Task<IEnumerable<string>> ListTableNames(CancellationToken cancellationToken = default(CancellationToken))

Parameters

Type	Name	Description
System.Threading.CancellationToken	cancellationToken	A cancellation token that can be used by other objects or threads to receive notice of cancellation.

Returns

Type	Description
System.Threading.Tasks.Task<System.Collections.Generic.IEnumerable<System.String>>	The task Enumerable containing the table names in the ledger.

Implements

IAsyncQldbDriver

System.IDisposable