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Merged
bkoelman merged 1 commit into from
Feb 3, 2026
Merged

Optimization: skip COUNT query when pagination is disabled #1915

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82 changes: 45 additions & 37 deletions src/Examples/NoEntityFrameworkExample/Services/InMemoryResourceService.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -50,17 +50,27 @@ public Task<IReadOnlyCollection<TResource>> GetAsync(CancellationToken cancellat
{
LogFiltersInTopScope();

if (SetPrimaryTotalCountIsZero())
QueryLayer queryLayer = _queryLayerComposer.ComposeFromConstraints(_resourceType);
int? pageSize = queryLayer.Pagination?.PageSize?.Value;

if (_options.IncludeTotalResourceCount && pageSize != null)
{
return Task.FromResult<IReadOnlyCollection<TResource>>(Array.Empty<TResource>());
}
_paginationContext.TotalResourceCount = GetResourceCountForPrimaryEndpoint(queryLayer.Filter);

QueryLayer queryLayer = _queryLayerComposer.ComposeFromConstraints(_resourceType);
if (_paginationContext.TotalResourceCount == 0)
{
return Task.FromResult<IReadOnlyCollection<TResource>>(Array.Empty<TResource>());
}
}

IEnumerable<TResource> dataSource = GetDataSource(_resourceType).Cast<TResource>();
TResource[] resources = _queryLayerToLinqConverter.ApplyQueryLayer(queryLayer, dataSource).ToArray();

if (queryLayer.Pagination?.PageSize?.Value == resources.Length)
if (pageSize == null)
{
_paginationContext.TotalResourceCount = resources.Length;
}
else if (pageSize == resources.Length)
{
_paginationContext.IsPageFull = true;
}
Expand Down Expand Up @@ -91,27 +101,17 @@ private void LogFiltersInTopScope()
}
}

private bool SetPrimaryTotalCountIsZero()
private int GetResourceCountForPrimaryEndpoint(FilterExpression? filter)
{
if (_options.IncludeTotalResourceCount)
var queryLayer = new QueryLayer(_resourceType)
{
var queryLayer = new QueryLayer(_resourceType)
{
Filter = _queryLayerComposer.GetPrimaryFilterFromConstraints(_resourceType)
};
Filter = filter
};

IEnumerable<TResource> dataSource = GetDataSource(_resourceType).Cast<TResource>();
IEnumerable<TResource> resources = _queryLayerToLinqConverter.ApplyQueryLayer(queryLayer, dataSource);

_paginationContext.TotalResourceCount = resources.Count();

if (_paginationContext.TotalResourceCount == 0)
{
return true;
}
}
IEnumerable<TResource> dataSource = GetDataSource(_resourceType).Cast<TResource>();
IEnumerable<TResource> resources = _queryLayerToLinqConverter.ApplyQueryLayer(queryLayer, dataSource);

return false;
return resources.Count();
}

/// <inheritdoc />
Expand Down Expand Up @@ -141,10 +141,14 @@ public Task<TResource> GetAsync([DisallowNull] TId id, CancellationToken cancell
throw new RelationshipNotFoundException(relationshipName, _resourceType.PublicName);
}

SetNonPrimaryTotalCount(id, relationship);

QueryLayer secondaryLayer = _queryLayerComposer.ComposeFromConstraints(relationship.RightType);
QueryLayer primaryLayer = _queryLayerComposer.WrapLayerForSecondaryEndpoint(secondaryLayer, _resourceType, id, relationship);
int? pageSize = secondaryLayer.Pagination?.PageSize?.Value;

if (_options.IncludeTotalResourceCount && relationship is HasManyAttribute hasManyRelationship && pageSize != null)
{
SetResourceCountForNonPrimaryEndpoint(id, hasManyRelationship);
}

IEnumerable<TResource> dataSource = GetDataSource(_resourceType).Cast<TResource>();
IEnumerable<TResource> primaryResources = _queryLayerToLinqConverter.ApplyQueryLayer(primaryLayer, dataSource);
Expand All @@ -157,31 +161,35 @@ public Task<TResource> GetAsync([DisallowNull] TId id, CancellationToken cancell

object? rightValue = relationship.GetValue(primaryResource);

if (rightValue is ICollection rightResources && secondaryLayer.Pagination?.PageSize?.Value == rightResources.Count)
if (rightValue is IEnumerable rightResources)
{
_paginationContext.IsPageFull = true;
int resourceCount = rightResources.Cast<object>().Count();

if (pageSize == null)
{
_paginationContext.TotalResourceCount = resourceCount;
}
else if (pageSize == resourceCount)
{
_paginationContext.IsPageFull = true;
}
}

return Task.FromResult(rightValue);
}

private void SetNonPrimaryTotalCount([DisallowNull] TId id, RelationshipAttribute relationship)
private void SetResourceCountForNonPrimaryEndpoint([DisallowNull] TId id, HasManyAttribute relationship)
{
if (_options.IncludeTotalResourceCount && relationship is HasManyAttribute hasManyRelationship)
{
FilterExpression? secondaryFilter = _queryLayerComposer.GetSecondaryFilterFromConstraints(id, hasManyRelationship);
FilterExpression? secondaryFilter = _queryLayerComposer.GetSecondaryFilterFromConstraints(id, relationship);

if (secondaryFilter == null)
{
return;
}

var queryLayer = new QueryLayer(hasManyRelationship.RightType)
if (secondaryFilter != null)
{
var queryLayer = new QueryLayer(relationship.RightType)
{
Filter = secondaryFilter
};

IEnumerable<IIdentifiable> dataSource = GetDataSource(hasManyRelationship.RightType);
IEnumerable<IIdentifiable> dataSource = GetDataSource(relationship.RightType);
IEnumerable<IIdentifiable> resources = _queryLayerToLinqConverter.ApplyQueryLayer(queryLayer, dataSource);

_paginationContext.TotalResourceCount = resources.Count();
Expand Down
19 changes: 19 additions & 0 deletions src/JsonApiDotNetCore.Annotations/CollectionConverter.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -60,6 +60,8 @@ public IEnumerable CopyToTypedCollection(IEnumerable source, Type collectionType
/// </summary>
private Type ToConcreteCollectionType(Type collectionType)
{
ArgumentNullException.ThrowIfNull(collectionType);

if (collectionType is { IsInterface: true, IsGenericType: true })
{
Type openCollectionType = collectionType.GetGenericTypeDefinition();
Expand Down Expand Up @@ -94,6 +96,23 @@ public IReadOnlyCollection<IIdentifiable> ExtractResources(object? value)
};
}

/// <summary>
/// Returns the number of elements in a collection of resources.
/// </summary>
public int GetCount(IEnumerable source)
{
ArgumentNullException.ThrowIfNull(source);

return source switch
{
List<IIdentifiable> resourceList => resourceList.Count,
HashSet<IIdentifiable> resourceSet => resourceSet.Count,
IReadOnlyCollection<IIdentifiable> resourceCollection => resourceCollection.Count,
IEnumerable<IIdentifiable> resources => resources.Count(),
_ => source.Cast<object>().Count()
};
}

/// <summary>
/// Returns the element type if the specified type is a generic collection, for example: <code><![CDATA[
/// IList<string> -> string
Expand Down
2 changes: 2 additions & 0 deletions src/JsonApiDotNetCore/Queries/IQueryLayerComposer.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,8 @@ public interface IQueryLayerComposer
/// <summary>
/// Builds a filter from constraints, used to determine total resource count on a primary collection endpoint.
/// </summary>
[Obsolete("This method is no longer used and will be removed in a future version.")]
// ReSharper disable once UnusedMemberInSuper.Global
FilterExpression? GetPrimaryFilterFromConstraints(ResourceType primaryResourceType);

/// <summary>
Expand Down
1 change: 1 addition & 0 deletions src/JsonApiDotNetCore/Queries/QueryLayerComposer.cs
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Expand Up @@ -44,6 +44,7 @@ public QueryLayerComposer(IEnumerable<IQueryConstraintProvider> constraintProvid
}

/// <inheritdoc />
[Obsolete("This method is no longer used and will be removed in a future version.")]
public FilterExpression? GetPrimaryFilterFromConstraints(ResourceType primaryResourceType)
{
// @formatter:wrap_chained_method_calls chop_always
Expand Down
73 changes: 56 additions & 17 deletions src/JsonApiDotNetCore/Services/JsonApiResourceService.cs
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Expand Up @@ -62,21 +62,26 @@ public virtual async Task<IReadOnlyCollection<TResource>> GetAsync(CancellationT

using IDisposable _ = CodeTimingSessionManager.Current.Measure("Service - Get resources");

if (_options.IncludeTotalResourceCount)
QueryLayer queryLayer = _queryLayerComposer.ComposeFromConstraints(_request.PrimaryResourceType);
int? pageSize = queryLayer.Pagination?.PageSize?.Value;

if (_options.IncludeTotalResourceCount && pageSize != null)
{
FilterExpression? topFilter = _queryLayerComposer.GetPrimaryFilterFromConstraints(_request.PrimaryResourceType);
_paginationContext.TotalResourceCount = await _repositoryAccessor.CountAsync(_request.PrimaryResourceType, topFilter, cancellationToken);
_paginationContext.TotalResourceCount = await _repositoryAccessor.CountAsync(_request.PrimaryResourceType, queryLayer.Filter, cancellationToken);

if (_paginationContext.TotalResourceCount == 0)
{
return Array.Empty<TResource>();
}
}

QueryLayer queryLayer = _queryLayerComposer.ComposeFromConstraints(_request.PrimaryResourceType);
IReadOnlyCollection<TResource> resources = await _repositoryAccessor.GetAsync<TResource>(queryLayer, cancellationToken);

if (queryLayer.Pagination?.PageSize?.Value == resources.Count)
if (pageSize == null)
{
_paginationContext.TotalResourceCount = resources.Count;
}
else if (pageSize == resources.Count)
{
_paginationContext.IsPageFull = true;
}
Expand Down Expand Up @@ -107,31 +112,43 @@ public virtual async Task<TResource> GetAsync([DisallowNull] TId id, Cancellatio
});

ArgumentNullException.ThrowIfNull(relationshipName);
AssertPrimaryResourceTypeInJsonApiRequestIsNotNull(_request.PrimaryResourceType);
AssertHasRelationship(_request.Relationship, relationshipName);
AssertPrimaryResourceTypeInJsonApiRequestIsNotNull(_request.PrimaryResourceType);
AssertSecondaryResourceTypeInJsonApiRequestIsNotNull(_request.SecondaryResourceType);

using IDisposable _ = CodeTimingSessionManager.Current.Measure("Service - Get secondary resource(s)");

if (_options.IncludeTotalResourceCount && _request.IsCollection)
QueryLayer secondaryLayer = _queryLayerComposer.ComposeFromConstraints(_request.SecondaryResourceType);
QueryLayer primaryLayer = _queryLayerComposer.WrapLayerForSecondaryEndpoint(secondaryLayer, _request.PrimaryResourceType, id, _request.Relationship);
int? pageSize = secondaryLayer.Pagination?.PageSize?.Value;

if (_options.IncludeTotalResourceCount && _request.IsCollection && pageSize != null)
{
await RetrieveResourceCountForNonPrimaryEndpointAsync(id, (HasManyAttribute)_request.Relationship, cancellationToken);

// We cannot return early when _paginationContext.TotalResourceCount == 0, because we don't know whether
// the parent resource exists. In case the parent does not exist, an error is produced below.
}

QueryLayer secondaryLayer = _queryLayerComposer.ComposeFromConstraints(_request.SecondaryResourceType!);
QueryLayer primaryLayer = _queryLayerComposer.WrapLayerForSecondaryEndpoint(secondaryLayer, _request.PrimaryResourceType, id, _request.Relationship);
IReadOnlyCollection<TResource> primaryResources = await _repositoryAccessor.GetAsync<TResource>(primaryLayer, cancellationToken);

TResource? primaryResource = primaryResources.SingleOrDefault();
AssertPrimaryResourceExists(primaryResource);

object? rightValue = _request.Relationship.GetValue(primaryResource);

if (rightValue is ICollection rightResources && secondaryLayer.Pagination?.PageSize?.Value == rightResources.Count)
if (rightValue is IEnumerable rightResources)
{
_paginationContext.IsPageFull = true;
int resourceCount = CollectionConverter.Instance.GetCount(rightResources);

if (pageSize == null)
{
_paginationContext.TotalResourceCount = resourceCount;
}
else if (pageSize == resourceCount)
{
_paginationContext.IsPageFull = true;
}
}

return rightValue;
Expand All @@ -147,31 +164,43 @@ public virtual async Task<TResource> GetAsync([DisallowNull] TId id, Cancellatio
});

ArgumentNullException.ThrowIfNull(relationshipName);
AssertPrimaryResourceTypeInJsonApiRequestIsNotNull(_request.PrimaryResourceType);
AssertHasRelationship(_request.Relationship, relationshipName);
AssertPrimaryResourceTypeInJsonApiRequestIsNotNull(_request.PrimaryResourceType);
AssertSecondaryResourceTypeInJsonApiRequestIsNotNull(_request.SecondaryResourceType);

using IDisposable _ = CodeTimingSessionManager.Current.Measure("Service - Get relationship");

if (_options.IncludeTotalResourceCount && _request.IsCollection)
QueryLayer secondaryLayer = _queryLayerComposer.ComposeSecondaryLayerForRelationship(_request.SecondaryResourceType);
QueryLayer primaryLayer = _queryLayerComposer.WrapLayerForSecondaryEndpoint(secondaryLayer, _request.PrimaryResourceType, id, _request.Relationship);
int? pageSize = secondaryLayer.Pagination?.PageSize?.Value;

if (_options.IncludeTotalResourceCount && _request.IsCollection && pageSize != null)
{
await RetrieveResourceCountForNonPrimaryEndpointAsync(id, (HasManyAttribute)_request.Relationship, cancellationToken);

// We cannot return early when _paginationContext.TotalResourceCount == 0, because we don't know whether
// the parent resource exists. In case the parent does not exist, an error is produced below.
}

QueryLayer secondaryLayer = _queryLayerComposer.ComposeSecondaryLayerForRelationship(_request.SecondaryResourceType!);
QueryLayer primaryLayer = _queryLayerComposer.WrapLayerForSecondaryEndpoint(secondaryLayer, _request.PrimaryResourceType, id, _request.Relationship);
IReadOnlyCollection<TResource> primaryResources = await _repositoryAccessor.GetAsync<TResource>(primaryLayer, cancellationToken);

TResource? primaryResource = primaryResources.SingleOrDefault();
AssertPrimaryResourceExists(primaryResource);

object? rightValue = _request.Relationship.GetValue(primaryResource);

if (rightValue is ICollection rightResources && secondaryLayer.Pagination?.PageSize?.Value == rightResources.Count)
if (rightValue is IEnumerable rightResources)
{
_paginationContext.IsPageFull = true;
int resourceCount = CollectionConverter.Instance.GetCount(rightResources);

if (pageSize == null)
{
_paginationContext.TotalResourceCount = resourceCount;
}
else if (pageSize == resourceCount)
{
_paginationContext.IsPageFull = true;
}
}

return rightValue;
Expand Down Expand Up @@ -677,6 +706,16 @@ private void AssertPrimaryResourceTypeInJsonApiRequestIsNotNull([SysNotNull] Res
}
}

[AssertionMethod]
private void AssertSecondaryResourceTypeInJsonApiRequestIsNotNull([SysNotNull] ResourceType? resourceType)
{
if (resourceType == null)
{
throw new InvalidOperationException(
$"Expected {nameof(IJsonApiRequest)}.{nameof(IJsonApiRequest.SecondaryResourceType)} not to be null at this point.");
}
}

[AssertionMethod]
private void AssertRelationshipInJsonApiRequestIsNotNull([SysNotNull] RelationshipAttribute? relationship)
{
Expand Down
6 changes: 1 addition & 5 deletions test/DapperTests/IntegrationTests/DapperTestContext.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -81,11 +81,7 @@ private WebApplicationFactory<TodoItem> CreateFactory()
builder.ConfigureServices(services =>
{
services.Replace(ServiceDescriptor.Singleton<TimeProvider>(new FrozenTimeProvider(FrozenTime)));

ServiceDescriptor scopedCaptureStore = services.Single(descriptor => descriptor.ImplementationType == typeof(SqlCaptureStore));
services.Remove(scopedCaptureStore);

services.AddSingleton<SqlCaptureStore>();
services.Replace(ServiceDescriptor.Singleton<SqlCaptureStore, SqlCaptureStore>());
});
});
}
Expand Down
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