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Implement asynchronous support in ODataJsonLightParameterReader (#2353)
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* Implement asynchronous support in ODataJsonLightParameterReader
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@gathogojr
gathogojr authored Mar 29, 2022
1 parent aa0cd73 commit 73d29b0
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Showing 9 changed files with 1,399 additions and 69 deletions.
86 changes: 71 additions & 15 deletions src/Microsoft.OData.Core/JsonLight/ODataJsonLightParameterReader.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -7,12 +7,12 @@
namespace Microsoft.OData.JsonLight
{
#region Namespaces

using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Threading.Tasks;
using Microsoft.OData.Metadata;
using Microsoft.OData.Edm;
using Microsoft.OData.Json;
using Microsoft.OData.Metadata;

#endregion Namespaces

Expand Down Expand Up @@ -70,8 +70,8 @@ protected override bool ReadAtStartImplementation()
this.jsonLightParameterDeserializer.ReadPayloadStart(
ODataPayloadKind.Parameter,
this.propertyAndAnnotationCollector,
/*isReadingNestedPayload*/false,
/*allowEmptyPayload*/true);
isReadingNestedPayload: false,
allowEmptyPayload: true);

return this.ReadAtStartImplementationSynchronously();
}
Expand All @@ -86,7 +86,7 @@ protected override bool ReadAtStartImplementation()
/// When the new state is Resource, the reader is positioned at the starting '{' of the resource payload.
/// When the new state is Resource Set or Collection, the reader is positioned at the starting '[' of the resource set or collection payload.
/// </remarks>
protected override Task<bool> ReadAtStartImplementationAsync()
protected override async Task<bool> ReadAtStartImplementationAsync()
{
Debug.Assert(this.State == ODataParameterReaderState.Start, "this.State == ODataParameterReaderState.Start");
Debug.Assert(this.jsonLightParameterDeserializer.JsonReader.NodeType == JsonNodeType.None, "Pre-Condition: expected JsonNodeType.None");
Expand All @@ -96,14 +96,14 @@ protected override Task<bool> ReadAtStartImplementationAsync()

// The parameter payload looks like "{ param1 : value1, ..., paramN : valueN }", where each value can be primitive, complex, collection, entity, resource set or collection.
// Position the reader on the first node
return this.jsonLightParameterDeserializer.ReadPayloadStartAsync(
await this.jsonLightParameterDeserializer.ReadPayloadStartAsync(
ODataPayloadKind.Parameter,
this.propertyAndAnnotationCollector,
/*isReadingNestedPayload*/false,
/*allowEmptyPayload*/true)
isReadingNestedPayload: false,
allowEmptyPayload: true).ConfigureAwait(false);

.FollowOnSuccessWith(t =>
this.ReadAtStartImplementationSynchronously());
return await this.ReadAtStartInternalImplementationAsync()
.ConfigureAwait(false);
}

/// <summary>
Expand Down Expand Up @@ -131,9 +131,18 @@ protected override bool ReadNextParameterImplementation()
/// When the new state is Resource, the reader is positioned at the starting '{' of the resource payload.
/// When the new state is Resource Set or Collection, the reader is positioned at the starting '[' of the resource set or collection payload.
/// </remarks>
protected override Task<bool> ReadNextParameterImplementationAsync()
protected override async Task<bool> ReadNextParameterImplementationAsync()
{
return TaskUtils.GetTaskForSynchronousOperation<bool>(this.ReadNextParameterImplementationSynchronously);
Debug.Assert(
this.State != ODataParameterReaderState.Start &&
this.State != ODataParameterReaderState.Exception &&
this.State != ODataParameterReaderState.Completed,
"The current state must not be Start, Exception or Completed.");

this.PopScope(this.State);

return await this.jsonLightParameterDeserializer.ReadNextParameterAsync(this.propertyAndAnnotationCollector)
.ConfigureAwait(false);
}

/// <summary>
Expand All @@ -153,7 +162,17 @@ protected override ODataReader CreateResourceReader(IEdmStructuredType expectedR
/// <returns>An <see cref="ODataReader"/> to read the resource value of type <paramref name="expectedResourceType"/>.</returns>
protected override Task<ODataReader> CreateResourceReaderAsync(IEdmStructuredType expectedResourceType)
{
return TaskUtils.GetTaskForSynchronousOperation<ODataReader>(() => this.CreateResourceReaderSynchronously(expectedResourceType));
Debug.Assert(expectedResourceType != null, "expectedResourceType != null");

return Task.FromResult<ODataReader>(
new ODataJsonLightReader(
this.jsonLightInputContext,
navigationSource: null,
expectedResourceType: expectedResourceType,
readingResourceSet: false,
readingParameter: true,
readingDelta: false,
listener: this));
}

/// <summary>
Expand All @@ -173,7 +192,17 @@ protected override ODataReader CreateResourceSetReader(IEdmStructuredType expect
/// <returns>An <see cref="ODataReader"/> to read the resource set value of type <paramref name="expectedResourceType"/>.</returns>
protected override Task<ODataReader> CreateResourceSetReaderAsync(IEdmStructuredType expectedResourceType)
{
return TaskUtils.GetTaskForSynchronousOperation<ODataReader>(() => this.CreateResourceSetReaderSynchronously(expectedResourceType));
Debug.Assert(expectedResourceType != null, "expectedResourceType != null");

return Task.FromResult<ODataReader>(
new ODataJsonLightReader(
this.jsonLightInputContext,
navigationSource: null,
expectedResourceType: expectedResourceType,
readingResourceSet: true,
readingParameter: true,
readingDelta: false,
listener: this));
}

/// <summary>
Expand Down Expand Up @@ -203,7 +232,11 @@ protected override ODataCollectionReader CreateCollectionReader(IEdmTypeReferenc
/// </remarks>
protected override Task<ODataCollectionReader> CreateCollectionReaderAsync(IEdmTypeReference expectedItemTypeReference)
{
return TaskUtils.GetTaskForSynchronousOperation<ODataCollectionReader>(() => this.CreateCollectionReaderSynchronously(expectedItemTypeReference));
Debug.Assert(this.jsonLightInputContext.Model.IsUserModel(), "Should have verified that we created the parameter reader with a user model.");
Debug.Assert(expectedItemTypeReference != null, "expectedItemTypeReference != null");

return Task.FromResult<ODataCollectionReader>(
new ODataJsonLightCollectionReader(this.jsonLightInputContext, expectedItemTypeReference, listener: this));
}

/// <summary>
Expand Down Expand Up @@ -288,5 +321,28 @@ private ODataCollectionReader CreateCollectionReaderSynchronously(IEdmTypeRefere
Debug.Assert(expectedItemTypeReference != null, "expectedItemTypeReference != null");
return new ODataJsonLightCollectionReader(this.jsonLightInputContext, expectedItemTypeReference, this /*IODataReaderListener*/);
}

/// <summary>
/// Asynchronous implementation of the reader logic when in state 'Start'.
/// </summary>
/// <returns>true if more items can be read from the reader; otherwise false.</returns>
/// <remarks>
/// Pre-Condition: JsonNodeType.None: assumes that the JSON reader has not been used yet.
/// Post-Condition: When the new state is Value, the reader is positioned at the closing '}' or at the name of the next parameter.
/// When the new state is Resource, the reader is positioned at the starting '{' of the resource payload.
/// When the new state is Resource Set or Collection, the reader is positioned at the starting '[' of the resource set or collection payload.
/// </remarks>
private async Task<bool> ReadAtStartInternalImplementationAsync()
{
if (this.jsonLightInputContext.JsonReader.NodeType == JsonNodeType.EndOfInput)
{
this.PopScope(ODataParameterReaderState.Start);
this.EnterScope(ODataParameterReaderState.Completed, null, null);
return false;
}

return await this.jsonLightParameterDeserializer.ReadNextParameterAsync(this.propertyAndAnnotationCollector)
.ConfigureAwait(false);
}
}
}
51 changes: 50 additions & 1 deletion src/Microsoft.OData.Core/ODataParameterReader.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -7,7 +7,8 @@
namespace Microsoft.OData
{
#region Namespaces
using System.Diagnostics.CodeAnalysis;

using System;
using System.Threading.Tasks;

#endregion Namespaces
Expand Down Expand Up @@ -75,5 +76,53 @@ public abstract object Value
/// <summary> Asynchronously reads the next item from the message payload. </summary>
/// <returns>A task that when completed indicates whether more items were read.</returns>
public abstract Task<bool> ReadAsync();

/// <summary>
/// This method asynchronously creates an <see cref="ODataReader"/> to read the resource value when the state is ODataParameterReaderState.Resource.
/// </summary>
/// <returns>
/// A task that represents the asynchronous operation.
/// The value of the TResult parameter contains an <see cref="ODataReader"/> to read the resource value when the state is ODataParameterReaderState.Resource.
/// </returns>
/// <remarks>
/// When the state is ODataParameterReaderState.Resource, the Name property of the <see cref="ODataParameterReader"/> returns the name of the parameter
/// and the Value property of the <see cref="ODataParameterReader"/> returns null. Calling this method in any other state will cause an ODataException to be thrown.
/// </remarks>
public virtual Task<ODataReader> CreateResourceReaderAsync()
{
throw new NotImplementedException();
}

/// <summary>
/// This method asynchronously creates an <see cref="ODataReader"/> to read the resource set value when the state is ODataParameterReaderState.ResourceSet.
/// </summary>
/// <returns>
/// A task that represents the asynchronous operation.
/// The value of the TResult parameter contains an <see cref="ODataReader"/> to read the resource set value when the state is ODataParameterReaderState.ResourceSet.
/// </returns>
/// <remarks>
/// When the state is ODataParameterReaderState.ResourceSet, the Name property of the <see cref="ODataParameterReader"/> returns the name of the parameter
/// and the Value property of the <see cref="ODataParameterReader"/> returns null. Calling this method in any other state will cause an ODataException to be thrown.
/// </remarks>
public virtual Task<ODataReader> CreateResourceSetReaderAsync()
{
throw new NotImplementedException();
}

/// <summary>
/// Asynchronously creates an <see cref="Microsoft.OData.ODataCollectionReader" /> to read the collection value when the state is ODataParameterReaderState.Collection.
/// </summary>
/// <returns>
/// A task that represents the asynchronous operation.
/// The value of the TResult parameter contains an <see cref="ODataCollectionReader"/> to read the collection value when the state is ODataParameterReaderState.Collection.
/// </returns>
/// <remarks>
/// When the state is ODataParameterReaderState.Collection, the Name property of the <see cref="ODataParameterReader"/> returns the name of the parameter
/// and the Value property of the <see cref="ODataParameterReader"/> returns null. Calling this method in any other state will cause an ODataException to be thrown.
/// </remarks>
public virtual Task<ODataCollectionReader> CreateCollectionReaderAsync()
{
throw new NotImplementedException();
}
}
}
67 changes: 49 additions & 18 deletions src/Microsoft.OData.Core/ODataParameterReaderCore.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -7,6 +7,7 @@
namespace Microsoft.OData
{
#region Namespaces

using System;
using System.Collections.Generic;
using System.Diagnostics;
Expand All @@ -15,6 +16,7 @@ namespace Microsoft.OData
using System.Threading.Tasks;
using Microsoft.OData.Edm;
using Microsoft.OData.Metadata;

#endregion Namespaces

/// <summary>
Expand All @@ -35,7 +37,7 @@ internal abstract class ODataParameterReaderCore : ODataParameterReader, IODataR
private readonly HashSet<string> parametersRead = new HashSet<string>(StringComparer.Ordinal);

/// <summary>Tracks the state of the sub-reader.</summary>
private SubReaderState subReaderState;
protected SubReaderState subReaderState;

/// <summary>
/// Constructor.
Expand All @@ -53,7 +55,7 @@ protected ODataParameterReaderCore(
}

/// <summary>Enum to track the state of the sub-reader.</summary>
private enum SubReaderState
protected enum SubReaderState
{
/// <summary>No sub-reader has been created for the current parameter.</summary>
None,
Expand Down Expand Up @@ -182,7 +184,7 @@ public override ODataCollectionReader CreateCollectionReader()
public override sealed bool Read()
{
this.VerifyCanRead(true);
return this.InterceptException(this.ReadSynchronously);
return this.InterceptException((thisParam) => thisParam.ReadSynchronously());
}

/// <summary>
Expand All @@ -192,7 +194,7 @@ public override sealed bool Read()
public override sealed Task<bool> ReadAsync()
{
this.VerifyCanRead(false);
return this.ReadAsynchronously().FollowOnFaultWith(t => this.EnterScope(ODataParameterReaderState.Exception, null, null));
return this.InterceptExceptionAsync((thisParam) => thisParam.ReadAsynchronously());
}

/// <summary>
Expand Down Expand Up @@ -432,6 +434,27 @@ protected virtual Task<bool> ReadAsynchronously()
return TaskUtils.GetTaskForSynchronousOperation<bool>(this.ReadImplementation);
}

/// <summary>
/// Verifies that one of CreateResourceReader(), CreateResourceSetReader(), CreateCollectionReader(),
/// CreateResourceReaderAsync(), CreateResourceSetReaderAsync() or CreateCollectionReaderAsync() can be called.
/// </summary>
/// <param name="expectedState">The expected state of the reader.</param>
protected void VerifyCanCreateSubReader(ODataParameterReaderState expectedState)
{
this.inputContext.VerifyNotDisposed();

if (this.State != expectedState)
{
throw new ODataException(Strings.ODataParameterReaderCore_InvalidCreateReaderMethodCalledForState(ODataParameterReaderCore.GetCreateReaderMethodName(expectedState), this.State));
}

if (this.subReaderState != SubReaderState.None)
{
Debug.Assert(this.Name != null, "this.Name != null");
throw new ODataException(Strings.ODataParameterReaderCore_CreateReaderAlreadyCalled(ODataParameterReaderCore.GetCreateReaderMethodName(expectedState), this.Name));
}
}

/// <summary>
/// Gets the corresponding create reader method name for the given state.
/// </summary>
Expand All @@ -444,36 +467,44 @@ private static string GetCreateReaderMethodName(ODataParameterReaderState state)
}

/// <summary>
/// Verifies that one of CreateResourceReader(), CreateResourceSetReader() or CreateCollectionReader() can be called.
/// Catch any exception thrown by the action passed in; in the exception case move the reader into
/// state ExceptionThrown and then rethrow the exception.
/// </summary>
/// <param name="expectedState">The expected state of the reader.</param>
private void VerifyCanCreateSubReader(ODataParameterReaderState expectedState)
/// <typeparam name="T">The type returned from the <paramref name="action"/> to execute.</typeparam>
/// <param name="action">The action to execute.</param>
/// <returns>The result of executing the <paramref name="action"/>.</returns>
private T InterceptException<T>(Func<ODataParameterReaderCore, T> action)
{
this.inputContext.VerifyNotDisposed();
if (this.State != expectedState)
try
{
throw new ODataException(Strings.ODataParameterReaderCore_InvalidCreateReaderMethodCalledForState(ODataParameterReaderCore.GetCreateReaderMethodName(expectedState), this.State));
return action(this);
}

if (this.subReaderState != SubReaderState.None)
catch (Exception e)
{
Debug.Assert(this.Name != null, "this.Name != null");
throw new ODataException(Strings.ODataParameterReaderCore_CreateReaderAlreadyCalled(ODataParameterReaderCore.GetCreateReaderMethodName(expectedState), this.Name));
if (ExceptionUtils.IsCatchableExceptionType(e))
{
this.EnterScope(ODataParameterReaderState.Exception, null, null);
}

throw;
}
}

/// <summary>
/// Catch any exception thrown by the action passed in; in the exception case move the reader into
/// state ExceptionThrown and then rethrow the exception.
/// </summary>
/// <typeparam name="T">The type returned from the <paramref name="action"/> to execute.</typeparam>
/// <typeparam name="TResult">The type returned from the <paramref name="action"/></typeparam>
/// <param name="action">The action to execute.</param>
/// <returns>The result of executing the <paramref name="action"/>.</returns>
private T InterceptException<T>(Func<T> action)
/// <returns>
/// A task that represents the asynchronous operation.
/// The value of the TResult parameter contains the result of executing the <paramref name="action"/>.
/// </returns>
private async Task<TResult> InterceptExceptionAsync<TResult>(Func<ODataParameterReaderCore, Task<TResult>> action)
{
try
{
return action();
return await action(this).ConfigureAwait(false);
}
catch (Exception e)
{
Expand Down
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