Support paging for DOM instances

SkylineCommunications · Nov 13, 2024 · 1ba133c · 1ba133c
1 parent 55eeeae
commit 1ba133c
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Showing 2 changed files with 126 additions and 12 deletions.
diff --git a/Utils.DOM/UnitTesting/DomPagingHandler.cs b/Utils.DOM/UnitTesting/DomPagingHandler.cs
@@ -0,0 +1,66 @@
+namespace Skyline.DataMiner.Utils.DOM.UnitTesting
+{
+	using System;
+	using System.Collections.Generic;
+
+	using Skyline.DataMiner.Net.Messages.SLDataGateway;
+
+	internal class DomPagingHandler<T> : IDisposable
+	{
+		private readonly IEnumerator<T> _enumerator;
+
+		private bool _hasNext;
+		private T _nextRow;
+
+		private bool _isDisposed;
+
+		public DomPagingHandler(IEnumerable<T> items)
+		{
+			if (items == null)
+			{
+				throw new ArgumentNullException(nameof(items));
+			}
+
+			_enumerator = items.GetEnumerator();
+			TryMoveNext();
+		}
+
+		public PagingCookie Cookie { get; } = PagingCookie.CreateNew();
+
+		public List<T> GetNextPage(long pageSize, out bool isLast)
+		{
+			var page = new List<T>();
+
+			for (int i = 0; i < pageSize && _hasNext; i++)
+			{
+				page.Add(_nextRow);
+				TryMoveNext();
+			}
+
+			if (!_hasNext)
+			{
+				Dispose();
+			}
+
+			isLast = !_hasNext;
+			return page;
+		}
+
+		public void Dispose()
+		{
+			if (_isDisposed)
+			{
+				return;
+			}
+
+			_enumerator?.Dispose();
+			_isDisposed = true;
+		}
+
+		private void TryMoveNext()
+		{
+			_hasNext = _enumerator.MoveNext();
+			_nextRow = _hasNext ? _enumerator.Current : default;
+		}
+	}
+}
diff --git a/Utils.DOM/UnitTesting/DomSLNetMessageHandler.cs b/Utils.DOM/UnitTesting/DomSLNetMessageHandler.cs
@@ -9,6 +9,7 @@
 	using Skyline.DataMiner.Net.Apps.DataMinerObjectModel;
 	using Skyline.DataMiner.Net.Apps.DataMinerObjectModel.CustomMessages;
 	using Skyline.DataMiner.Net.Messages;
+	using Skyline.DataMiner.Net.Messages.SLDataGateway;
 	using Skyline.DataMiner.Net.Sections;
 
 	/// <summary>
@@ -21,6 +22,8 @@ public class DomSLNetMessageHandler
 		private readonly ConcurrentDictionary<Guid, DomInstance> _instances = new ConcurrentDictionary<Guid, DomInstance>();
 		private readonly ConcurrentDictionary<Guid, DomBehaviorDefinition> _behaviorDefinitions = new ConcurrentDictionary<Guid, DomBehaviorDefinition>();
 
+		private readonly ConcurrentDictionary<PagingCookie, DomPagingHandler<DomInstance>> _pagingHandlers = new ConcurrentDictionary<PagingCookie, DomPagingHandler<DomInstance>>();
+
 		/// <summary>
 		/// Initializes a new instance of the <see cref="DomSLNetMessageHandler"/> class.
 		/// </summary>
@@ -201,24 +204,69 @@ public bool TryHandleMessage(DMSMessage message, out DMSMessage response)
 				#region Instances
 
 				case ManagerStoreReadRequest<DomInstance> request:
-					var instances = request.Query.ExecuteInMemory(_instances.Values).ToList();
-					response = new ManagerStoreCrudResponse<DomInstance>(instances);
-					return true;
+					{
+						var instances = request.Query.ExecuteInMemory(_instances.Values).ToList();
+						response = new ManagerStoreCrudResponse<DomInstance>(instances);
+						return true;
+					}
 
 				case ManagerStoreCreateRequest<DomInstance> request:
-					_instances[request.Object.ID.SafeId()] = request.Object;
-					response = new ManagerStoreCrudResponse<DomInstance>(request.Object);
-					return true;
+					{
+						_instances[request.Object.ID.SafeId()] = request.Object;
+						response = new ManagerStoreCrudResponse<DomInstance>(request.Object);
+						return true;
+					}
 
 				case ManagerStoreUpdateRequest<DomInstance> request:
-					_instances[request.Object.ID.SafeId()] = request.Object;
-					response = new ManagerStoreCrudResponse<DomInstance>(request.Object);
-					return true;
+					{
+						_instances[request.Object.ID.SafeId()] = request.Object;
+						response = new ManagerStoreCrudResponse<DomInstance>(request.Object);
+						return true;
+					}
 
 				case ManagerStoreDeleteRequest<DomInstance> request:
-					_instances.TryRemove(request.Object.ID.SafeId(), out _);
-					response = new ManagerStoreCrudResponse<DomInstance>(request.Object);
-					return true;
+					{
+						_instances.TryRemove(request.Object.ID.SafeId(), out _);
+						response = new ManagerStoreCrudResponse<DomInstance>(request.Object);
+						return true;
+					}
+
+				case ManagerStoreStartPagingRequest<DomInstance> request:
+					{
+						var instances = request.Filter.ExecuteInMemory(_instances.Values).ToList();
+						var pagingHandler = new DomPagingHandler<DomInstance>(instances);
+						_pagingHandlers.TryAdd(pagingHandler.Cookie, pagingHandler);
+
+						var nextPage = pagingHandler.GetNextPage(request.PreferredPageSize, out var isLast);
+
+						if (isLast)
+						{
+							_pagingHandlers.TryRemove(pagingHandler.Cookie, out pagingHandler);
+							pagingHandler.Dispose();
+						}
+
+						response = new ManagerStorePagingResponse<DomInstance>(nextPage, isLast, pagingHandler.Cookie);
+						return true;
+					}
+
+				case ManagerStoreNextPagingRequest<DomInstance> request:
+					{
+						if (!_pagingHandlers.TryGetValue(request.PagingCookie, out var pagingHandler))
+						{
+							throw new InvalidOperationException($"Invalid paging cookie: {request.PagingCookie}");
+						}
+
+						var nextPage = pagingHandler.GetNextPage(request.PreferredPageSize, out var isLast);
+
+						if (isLast)
+						{
+							_pagingHandlers.TryRemove(pagingHandler.Cookie, out pagingHandler);
+							pagingHandler.Dispose();
+						}
+
+						response = new ManagerStorePagingResponse<DomInstance>(nextPage, isLast, pagingHandler.Cookie);
+						return true;
+					}
 
 				#endregion