/// <summary>
/// Poll for new messages in a stream. If new messages are found beyond the last consumed position then they
/// will be delivered to the <seealso cref="FragmentHandler"/> up to a limited number of fragments as specified.
///
/// Use a <see cref="FragmentAssembler"/> to assemble messages which span multiple fragments.
/// </summary>
/// <param name="fragmentHandler"> to which message fragments are delivered. </param>
/// <param name="fragmentLimit"> for the number of fragments to be consumed during one polling operation. </param>
/// <returns> the number of fragments that have been consumed. </returns>
/// <seealso cref="FragmentAssembler" />
/// <seealso cref="ImageFragmentAssembler" />
public int Poll(IFragmentHandler fragmentHandler, int fragmentLimit)
{
if (_isClosed)
{
return(0);
}
var position = _subscriberPosition.Get();
return(TermReader.Read(
ActiveTermBuffer(position),
(int)position & _termLengthMask,
fragmentHandler,
fragmentLimit,
_header,
_errorHandler,
position,
_subscriberPosition));
}
public long Position()
{
if (_isClosed)
{
return(_finalPosition);
}
return(_subscriberPosition.Get());
}
public void ShouldPollNoFragmentsToBoundedControlledFragmentHandlerWithMaxPositionBeforeInitialPosition()
{
var initialPosition = LogBufferDescriptor.ComputePosition(INITIAL_TERM_ID, 0, POSITION_BITS_TO_SHIFT, INITIAL_TERM_ID);
var maxPosition = initialPosition - DataHeaderFlyweight.HEADER_LENGTH;
Position.SetOrdered(initialPosition);
var image = CreateImage();
InsertDataFrame(INITIAL_TERM_ID, OffsetForFrame(0));
InsertDataFrame(INITIAL_TERM_ID, OffsetForFrame(1));
A.CallTo(() => MockControlledFragmentHandler.OnFragment(A <UnsafeBuffer> ._, A <int> ._, A <int> ._, A <Header> ._)).Returns(ControlledFragmentHandlerAction.CONTINUE);
var fragmentsRead = image.BoundedControlledPoll(MockControlledFragmentHandler, maxPosition, int.MaxValue);
Assert.That(fragmentsRead, Is.EqualTo(0));
Assert.That(Position.Get(), Is.EqualTo(initialPosition));
A.CallTo(() => MockControlledFragmentHandler.OnFragment(A <UnsafeBuffer> ._, DataHeaderFlyweight.HEADER_LENGTH, DATA.Length, A <Header> ._)).MustNotHaveHappened();
}
/// <summary>
/// Construct a new image over a log to represent a stream of messages from a <seealso cref="Publication"/>.
/// </summary>
/// <param name="subscription"> to which this <seealso cref="Image"/> belongs. </param>
/// <param name="sessionId"> of the stream of messages. </param>
/// <param name="subscriberPosition"> for indicating the position of the subscriber in the stream. </param>
/// <param name="logBuffers"> containing the stream of messages. </param>
/// <param name="errorHandler"> to be called if an error occurs when polling for messages. </param>
/// <param name="sourceIdentity"> of the source sending the stream of messages. </param>
/// <param name="correlationId"> of the request to the media driver. </param>
public Image(Subscription subscription, int sessionId, IPosition subscriberPosition, LogBuffers logBuffers, ErrorHandler errorHandler, string sourceIdentity, long correlationId)
{
Subscription = subscription;
SessionId = sessionId;
_subscriberPosition = subscriberPosition;
_logBuffers = logBuffers;
_errorHandler = errorHandler;
SourceIdentity = sourceIdentity;
CorrelationId = correlationId;
_joiningPosition = subscriberPosition.Get();
_termBuffers = logBuffers.TermBuffers();
var termLength = logBuffers.TermLength();
_termLengthMask = termLength - 1;
_positionBitsToShift = IntUtil.NumberOfTrailingZeros(termLength);
_initialTermId = LogBufferDescriptor.InitialTermId(logBuffers.MetaDataBuffer());
_header = new Header(LogBufferDescriptor.InitialTermId(logBuffers.MetaDataBuffer()), _positionBitsToShift, this);
}
//这个里面是通用方法,实现增删改查排序(动软代码生成器自动生成)
#region Method
/// <summary>
/// 获取用户信息
/// </summary>
/// <param name="id"></param>
/// <returns></returns>
public Position Get(int id)
{
return(dao.Get(id));
}
