| /* |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| namespace DotPulsar.Internal |
| { |
| using Abstractions; |
| using DotPulsar.Abstractions; |
| using DotPulsar.Exceptions; |
| using DotPulsar.Internal.PulsarApi; |
| using Events; |
| using System; |
| using System.Threading; |
| using System.Threading.Tasks; |
| |
| public sealed class Reader<TMessage> : IEstablishNewChannel, IReader<TMessage> |
| { |
| private readonly Guid _correlationId; |
| private readonly IRegisterEvent _eventRegister; |
| private IConsumerChannel<TMessage> _channel; |
| private readonly IExecute _executor; |
| private readonly IStateChanged<ReaderState> _state; |
| private readonly IConsumerChannelFactory<TMessage> _factory; |
| private int _isDisposed; |
| |
| public Uri ServiceUrl { get; } |
| public string Topic { get; } |
| |
| public Reader( |
| Guid correlationId, |
| Uri serviceUrl, |
| string topic, |
| IRegisterEvent eventRegister, |
| IConsumerChannel<TMessage> initialChannel, |
| IExecute executor, |
| IStateChanged<ReaderState> state, |
| IConsumerChannelFactory<TMessage> factory) |
| { |
| _correlationId = correlationId; |
| ServiceUrl = serviceUrl; |
| Topic = topic; |
| _eventRegister = eventRegister; |
| _channel = initialChannel; |
| _executor = executor; |
| _state = state; |
| _factory = factory; |
| _isDisposed = 0; |
| |
| _eventRegister.Register(new ReaderCreated(_correlationId)); |
| } |
| |
| public async ValueTask<ReaderState> OnStateChangeTo(ReaderState state, CancellationToken cancellationToken) |
| => await _state.StateChangedTo(state, cancellationToken).ConfigureAwait(false); |
| |
| public async ValueTask<ReaderState> OnStateChangeFrom(ReaderState state, CancellationToken cancellationToken) |
| => await _state.StateChangedFrom(state, cancellationToken).ConfigureAwait(false); |
| |
| public bool IsFinalState() |
| => _state.IsFinalState(); |
| |
| public bool IsFinalState(ReaderState state) |
| => _state.IsFinalState(state); |
| |
| public async ValueTask<MessageId> GetLastMessageId(CancellationToken cancellationToken) |
| { |
| ThrowIfDisposed(); |
| |
| var getLastMessageId = new CommandGetLastMessageId(); |
| return await _executor.Execute(() => GetLastMessageId(getLastMessageId, cancellationToken), cancellationToken).ConfigureAwait(false); |
| } |
| |
| private async ValueTask<MessageId> GetLastMessageId(CommandGetLastMessageId command, CancellationToken cancellationToken) |
| => await _channel.Send(command, cancellationToken).ConfigureAwait(false); |
| |
| public async ValueTask<IMessage<TMessage>> Receive(CancellationToken cancellationToken) |
| { |
| ThrowIfDisposed(); |
| |
| return await _executor.Execute(() => ReceiveMessage(cancellationToken), cancellationToken).ConfigureAwait(false); |
| } |
| |
| private async ValueTask<IMessage<TMessage>> ReceiveMessage(CancellationToken cancellationToken) |
| => await _channel.Receive(cancellationToken).ConfigureAwait(false); |
| |
| public async ValueTask Seek(MessageId messageId, CancellationToken cancellationToken) |
| { |
| ThrowIfDisposed(); |
| |
| var seek = new CommandSeek { MessageId = messageId.ToMessageIdData() }; |
| await _executor.Execute(() => Seek(seek, cancellationToken), cancellationToken).ConfigureAwait(false); |
| } |
| |
| public async ValueTask Seek(ulong publishTime, CancellationToken cancellationToken) |
| { |
| ThrowIfDisposed(); |
| |
| var seek = new CommandSeek { MessagePublishTime = publishTime }; |
| await _executor.Execute(() => Seek(seek, cancellationToken), cancellationToken).ConfigureAwait(false); |
| } |
| |
| public async ValueTask DisposeAsync() |
| { |
| if (Interlocked.Exchange(ref _isDisposed, 1) != 0) |
| return; |
| |
| _eventRegister.Register(new ReaderDisposed(_correlationId)); |
| await _channel.ClosedByClient(CancellationToken.None).ConfigureAwait(false); |
| await _channel.DisposeAsync().ConfigureAwait(false); |
| } |
| |
| private async Task Seek(CommandSeek command, CancellationToken cancellationToken) |
| => await _channel.Send(command, cancellationToken).ConfigureAwait(false); |
| |
| public async Task EstablishNewChannel(CancellationToken cancellationToken) |
| { |
| var channel = await _executor.Execute(() => _factory.Create(cancellationToken), cancellationToken).ConfigureAwait(false); |
| |
| var oldChannel = _channel; |
| _channel = channel; |
| |
| if (oldChannel is not null) |
| await oldChannel.DisposeAsync().ConfigureAwait(false); |
| } |
| |
| private void ThrowIfDisposed() |
| { |
| if (_isDisposed != 0) |
| throw new ReaderDisposedException(GetType().FullName!); |
| } |
| } |
| } |