LogRecordSequence.BeginAppend Method (ArraySegment<Byte>, SequenceNumber, SequenceNumber, RecordAppendOptions, ReservationCollection, AsyncCallback, Object)


Begins an asynchronous append operation. This method cannot be inherited.

Namespace:   System.IO.Log
Assembly:  System.IO.Log (in System.IO.Log.dll)

public IAsyncResult BeginAppend(
	ArraySegment<byte> data,
	SequenceNumber nextUndoRecord,
	SequenceNumber previousRecord,
	RecordAppendOptions recordAppendOptions,
	ReservationCollection reservations,
	AsyncCallback callback,
	object state


Type: System.ArraySegment<Byte>

A list of byte array segments that will be concatenated and appended as the record.

Type: System.IO.Log.SequenceNumber

The sequence number of the next record in the user-specified order.

Type: System.IO.Log.SequenceNumber

The sequence number of the next record in Previous order.

Type: System.IO.Log.RecordAppendOptions

A valid value of RecordAppendOptions that specifies how the data should be written.

Type: System.IO.Log.ReservationCollection

A ReservationCollection that contains the reservation that should be used for this record.

Type: System.AsyncCallback

An optional asynchronous callback, to be called when the append is complete.

Type: System.Object

A user-provided object that distinguishes this particular asynchronous append request from other requests.

Return Value

Type: System.IAsyncResult

An IAsyncResult that represents the asynchronous append, which could still be pending.

Exception Condition

userRecord or previousRecord is not valid for this sequence.


data cannot be appended because it is larger than the maximum record size.


reservations was not created by this record sequence.


One or more of the arguments are null.


userRecord or previousRecord is not between the base and last sequence numbers of this sequence.


The request could not be performed because of an unexpected I/O exception.


The request could not be performed because of an I/O device error.


The operation cannot be performed because the record sequence was opened with read-only access.


The method was called after the sequence has been disposed of.


There is not enough memory to continue the execution of the program.


The record sequence is full.


Access for the specified log sequence is denied by the operating system.


No reservation large enough to fit data can be found in reservations.

You should pass the IAsyncResult returned by this method to the EndAppend method to ensure that the append operation has completed and resources can be freed appropriately. If an error has occurred during an asynchronous append, an exception is not thrown until the EndAppend method is called with the IAsyncResult returned by this method.

Data contained in the data parameter will be concatenated into a single byte array for appending as the record. However, no provision is made for splitting data back into array segments when the record is read.

The appended record will consume space that has been previously reserved, using a reservation specified by the reservations parameter. If the append succeeds, it will consume the smallest reservation area that can hold the data, and that reservation area will be removed from the collection.

Normally, this method completes before the record has been written. To ensure that a record has been written, either specify the ForceFlush flag using the recordAppendOptions parameter, or call the Flush method.

.NET Framework
Available since 3.0
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