Azure · timtay-microsoft · Mar 21, 2023 · Mar 14, 2023 · Mar 14, 2023 · Mar 14, 2023
@@ -284,8 +284,9 @@ These span across all service clients.
 #### Notable breaking changes
 
 - Operations that offer concurrency protection using `ETag`s, now take a parameter `onlyIfUnchanged` that relies on the ETag property of the submitted entity.
-- `IotHubServiceClient.Query.CreateAsync<T>(...)` is now async.
-  - Call `QueryResponse<T>.MoveNextAsync()` in a loop (end when it returns `false`) and access `QueryResponse<T>.Current`.
+- `IotHubServiceClient.Query.CreateAsync<T>(...)` now returns an `AsyncPageable` of the queried results.
+  - Iterate on entries by using `await foreach (ClientTwin queriedTwin in client.Query.CreateAsync<ClientTwin>(queryText))`.
+  - Iterate on pages of entries by using `await foreach (Page<ClientTwin> queriedTwinPage in _client.Query.CreateAsync<ClientTwin>(queryText).AsPages())`
 - `JobProperties` properties that hold Azure Storage SAS URIs are now of type `System.Uri` instead of `string`.
 - `JobProperties` has been split into several classes with only the necessary properties for the specified operation.
   - See `ExportJobProperties`, `ImportJobProperties`, and `IotHubJobResponse`.
@@ -378,7 +379,7 @@ These span across all service clients.
 
 #### Notable breaking changes
 - `JobClient.ScheduleTwinUpdateAsync(...)` previously returned a `JobResponse`, now returns `ScheduledJob`.
-- `ScheduleJobs.GetAsync()` return type has changed to `QueryResponse<ScheduledJob>` from `IEnumerable<JobResponse>`.
+- `ScheduleJobs.GetAsync()` return type has changed to `AsyncPageable<ScheduledJob>` from `IEnumerable<JobResponse>`.
 
 | v1 API | Equivalent v2 API | Notes |
 |:---|:---|:---|

@@ -5,6 +5,7 @@
 using System.Net;
 using System.Security.Authentication;
 using System.Threading.Tasks;
+using Azure;
 using FluentAssertions;
 using Microsoft.Azure.Devices.Client;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
@@ -23,7 +24,7 @@ public async Task ServiceClient_QueryDevicesInvalidServiceCertificateHttp_Fails(
             using var sc = new IotHubServiceClient(TestConfiguration.IotHub.ConnectionStringInvalidServiceCertificate);
 
             // act
-            Func<Task> act = async () => await sc.Query.CreateAsync<ClientTwin>("select * from devices").ConfigureAwait(false);
+            Func<Task> act = async () => await sc.Query.CreateAsync<ClientTwin>("select * from devices").GetAsyncEnumerator().MoveNextAsync().ConfigureAwait(false);
 
             // assert
             var error = await act.Should().ThrowAsync<IotHubServiceException>();

@@ -5,6 +5,7 @@
 using System.Collections.Generic;
 using System.Text.Json;
 using System.Threading.Tasks;
+using Azure;
 
 namespace Microsoft.Azure.Devices.Samples.JobsSample
 {
@@ -67,11 +68,9 @@ public async Task RunSampleAsync()
             }
 
             // *************************************** Get all Jobs ***************************************
-            QueryResponse<ScheduledJob> queryResults = await _jobClient.ScheduledJobs.CreateQueryAsync();
+            AsyncPageable<ScheduledJob> queryResults =  _jobClient.ScheduledJobs.CreateQueryAsync();
 
-            IEnumerable<ScheduledJob> getJobs = queryResults.CurrentPage;
-
-            foreach (ScheduledJob job in getJobs)
+            await foreach (ScheduledJob job in queryResults)
             {
                 Console.WriteLine(JsonSerializer.Serialize(job, new JsonSerializerOptions { WriteIndented = true }));
             }

@@ -8,6 +8,7 @@
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+using Azure;
 using Azure.Storage.Blobs;
 using Azure.Storage.Sas;
 using Newtonsoft.Json;
@@ -173,14 +174,15 @@ private async Task<int> PrintDeviceCountAsync()
             try
             {
                 string countSqlQuery = "select count() AS numberOfDevices from devices";
-                QueryResponse<Dictionary<string, int>> countQuery = await _hubClient.Query.CreateAsync<Dictionary<string, int>>(countSqlQuery);
-                if (!await countQuery.MoveNextAsync())
+                AsyncPageable<Dictionary<string, int>> countQuery = _hubClient.Query.CreateAsync<Dictionary<string, int>>(countSqlQuery);
+                IAsyncEnumerator<Dictionary<string, int>> enumerator = countQuery.GetAsyncEnumerator();
+                if (!await enumerator.MoveNextAsync())
                 {
                     Console.WriteLine($"Failed to run device count query.");
                     return 0;
                 }
 
-                if (!countQuery.Current.TryGetValue("numberOfDevices", out deviceCount))
+                if (!enumerator.Current.TryGetValue("numberOfDevices", out deviceCount))
                 {
                     Console.WriteLine($"Failed to get device count from query result.");
                     return 0;
@@ -224,11 +226,13 @@ private async Task<IReadOnlyList<ExportImportDevice>> GetDeviceIdsToDeleteAsync(
             }
             string queryText = queryTextSb.ToString();
             Console.WriteLine($"Using query: {queryText}");
-            var options = new QueryOptions { PageSize = 1000 };
-            QueryResponse<DeviceQueryResult> devicesQuery = await _hubClient.Query.CreateAsync<DeviceQueryResult>(queryText, options);
-            while (await devicesQuery.MoveNextAsync())
+            AsyncPageable<DeviceQueryResult> devicesQuery = _hubClient.Query.CreateAsync<DeviceQueryResult>(queryText);
+            await foreach (Page<DeviceQueryResult> page in devicesQuery.AsPages(null, 1000))
             {
-                devicesToDelete.Add(new ExportImportDevice(new Device(devicesQuery.Current.DeviceId), ImportMode.Delete));
+                foreach (DeviceQueryResult queryResult in page.Values)
+                {
+                    devicesToDelete.Add(new ExportImportDevice(new Device(queryResult.DeviceId), ImportMode.Delete));
+                }
             }
 
             return devicesToDelete;

@@ -5,6 +5,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
+using Azure;
 
 namespace Microsoft.Azure.Devices.Samples
 {
@@ -158,20 +159,19 @@ private async Task EnumerateTwinsAsync()
             string queryText = $"SELECT * FROM devices WHERE STARTSWITH(id, '{_parameters.DevicePrefix}')";
             Console.WriteLine($"Using query text of: {queryText}");
 
-            QueryResponse<ClientTwin> query = await _client.Query.CreateAsync<ClientTwin>(queryText);
+            AsyncPageable<ClientTwin> query = _client.Query.CreateAsync<ClientTwin>(queryText);
 
-            while (await query.MoveNextAsync())
+            await foreach (ClientTwin queriedTwin in query)
             {
-                ClientTwin twin = query.Current;
-                Console.WriteLine($"{twin.DeviceId}");
-                Console.WriteLine($"\tIs edge: {twin.Capabilities.IsIotEdge}");
-                if (!string.IsNullOrWhiteSpace(twin.DeviceScope))
+                Console.WriteLine($"{queriedTwin.DeviceId}");
+                Console.WriteLine($"\tIs edge: {queriedTwin.Capabilities.IsIotEdge}");
+                if (!string.IsNullOrWhiteSpace(queriedTwin.DeviceScope))
                 {
-                    Console.WriteLine($"\tDevice scope: {twin.DeviceScope}");
+                    Console.WriteLine($"\tDevice scope: {queriedTwin.DeviceScope}");
                 }
-                if (twin.ParentScopes?.Any() ?? false)
+                if (queriedTwin.ParentScopes?.Any() ?? false)
                 {
-                    Console.WriteLine($"\tParent scope: {twin.ParentScopes[0]}");
+                    Console.WriteLine($"\tParent scope: {queriedTwin.ParentScopes[0]}");
                 }
             }
         }

@@ -6,7 +6,7 @@ namespace Microsoft.Azure.Devices
     /// <summary>
     /// Specifies the options associated with job queries.
     /// </summary>
-    public class JobQueryOptions : QueryOptions
+    public class JobQueryOptions
     {
         /// <summary>
         /// The job type to query.

@@ -7,6 +7,7 @@
 using System.Net.Http;
 using System.Threading;
 using System.Threading.Tasks;
+using Azure;
 
 namespace Microsoft.Azure.Devices
 {
@@ -121,7 +122,7 @@ await _internalRetryHandler
         /// For a complete list of possible error cases, see <see cref="IotHubServiceErrorCode"/>.
         /// </exception>
         /// <exception cref="OperationCanceledException">If the provided <paramref name="cancellationToken"/> has requested cancellation.</exception>
-        public virtual Task<QueryResponse<ScheduledJob>> CreateQueryAsync(JobQueryOptions options = null, CancellationToken cancellationToken = default)
+        public virtual AsyncPageable<ScheduledJob> CreateQueryAsync(JobQueryOptions options = null, CancellationToken cancellationToken = default)
         {
             return _queryClient.CreateJobsQueryAsync(options, cancellationToken);
         }

@@ -18,12 +18,12 @@ internal sealed class QueriedPage<T>
         // in an async function.
         internal QueriedPage(HttpResponseMessage response, string payload)
         {
-            Items = JsonConvert.DeserializeObject<IEnumerable<T>>(payload);
+            Items = JsonConvert.DeserializeObject<IReadOnlyList<T>>(payload);
             ContinuationToken = response.Headers.SafeGetValue(ContinuationTokenHeader);
         }
 
         [JsonProperty("items")]
-        internal IEnumerable<T> Items { get; set; }
+        internal IReadOnlyList<T> Items { get; set; }
 
         [JsonProperty("continuationToken")]
         internal string ContinuationToken { get; set; }

@@ -0,0 +1,60 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using Azure;
+
+namespace Microsoft.Azure.Devices
+{
+    /// <summary>
+    /// Copy of a subset of the helper functions defined in the Azure.Core class by the same name:
+    /// https://github.com/Azure/autorest.csharp/blob/main/src/assets/Generator.Shared/PageableHelpers.cs
+    /// </summary>
+    internal static class PageableHelpers
+    {
+        internal static AsyncPageable<T> CreateAsyncEnumerable<T>(Func<int?, Task<Page<T>>> firstPageFunc, Func<string, int?, Task<Page<T>>> nextPageFunc, int? pageSize = default) where T : notnull
+        {
+            AsyncPageFunc<T> first = (continuationToken, pageSizeHint) => firstPageFunc(pageSizeHint);
+            AsyncPageFunc<T> next = nextPageFunc != null ? new AsyncPageFunc<T>(nextPageFunc) : null;
+            return new FuncAsyncPageable<T>(first, next, pageSize);
+        }
+
+        internal delegate Task<Page<T>> AsyncPageFunc<T>(string continuationToken = default, int? pageSizeHint = default);
+        internal delegate Page<T> PageFunc<T>(string continuationToken = default, int? pageSizeHint = default);
+
+        internal class FuncAsyncPageable<T> : AsyncPageable<T> where T : notnull
+        {
+            private readonly AsyncPageFunc<T> _firstPageFunc;
+            private readonly AsyncPageFunc<T> _nextPageFunc;
+            private readonly int? _defaultPageSize;
+
+            internal FuncAsyncPageable(AsyncPageFunc<T> firstPageFunc, AsyncPageFunc<T> nextPageFunc, int? defaultPageSize = default)
+            {
+                _firstPageFunc = firstPageFunc;
+                _nextPageFunc = nextPageFunc;
+                _defaultPageSize = defaultPageSize;
+            }
+
+            public override async IAsyncEnumerable<Page<T>> AsPages(string continuationToken = default, int? pageSizeHint = default)
+            {
+                AsyncPageFunc<T> pageFunc = string.IsNullOrEmpty(continuationToken) ? _firstPageFunc : _nextPageFunc;
+
+                if (pageFunc == null)
+                {
+                    yield break;
+                }
+
+                int? pageSize = pageSizeHint ?? _defaultPageSize;
+                do
+                {
+                    Page<T> pageResponse = await pageFunc(continuationToken, pageSize).ConfigureAwait(false);
+                    yield return pageResponse;
+                    continuationToken = pageResponse.ContinuationToken;
+                    pageFunc = _nextPageFunc;
+                } while (!string.IsNullOrEmpty(continuationToken) && pageFunc != null);
+            }
+        }
+    }
+}