Files
jellyfin/src/Jellyfin.Database/Jellyfin.Database.Implementations/JellyfinQueryHelperExtensions.cs
2026-05-04 23:40:07 +02:00

282 lines
13 KiB
C#

#pragma warning disable RS0030 // Do not use banned APIs
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Reflection;
using Jellyfin.Database.Implementations.Entities;
using Microsoft.EntityFrameworkCore;
namespace Jellyfin.Database.Implementations;
/// <summary>
/// Contains a number of query related extensions.
/// </summary>
public static class JellyfinQueryHelperExtensions
{
private static readonly MethodInfo _containsMethodGenericCache = typeof(Enumerable).GetMethods(BindingFlags.Public | BindingFlags.Static).First(m => m.Name == nameof(Enumerable.Contains) && m.GetParameters().Length == 2);
private static readonly MethodInfo _efParameterInstruction = typeof(EF).GetMethod(nameof(EF.Parameter), BindingFlags.Public | BindingFlags.Static)!;
private static readonly ConcurrentDictionary<Type, MethodInfo> _containsQueryCache = new();
/// <summary>
/// Builds an optimised query checking one property against a list of values while maintaining an optimal query.
/// </summary>
/// <typeparam name="TEntity">The entity.</typeparam>
/// <typeparam name="TProperty">The property type to compare.</typeparam>
/// <param name="query">The source query.</param>
/// <param name="oneOf">The list of items to check.</param>
/// <param name="property">Property expression.</param>
/// <returns>A Query.</returns>
public static IQueryable<TEntity> WhereOneOrMany<TEntity, TProperty>(this IQueryable<TEntity> query, IList<TProperty> oneOf, Expression<Func<TEntity, TProperty>> property)
{
return query.Where(OneOrManyExpressionBuilder(oneOf, property));
}
/// <summary>
/// Builds a query that checks referenced ItemValues for a cross BaseItem lookup.
/// </summary>
/// <param name="baseQuery">The source query.</param>
/// <param name="context">The database context.</param>
/// <param name="itemValueType">The type of item value to reference.</param>
/// <param name="referenceIds">The list of BaseItem ids to check matches.</param>
/// <param name="invert">If set an exclusion check is performed instead.</param>
/// <returns>A Query.</returns>
public static IQueryable<BaseItemEntity> WhereReferencedItem(
this IQueryable<BaseItemEntity> baseQuery,
JellyfinDbContext context,
ItemValueType itemValueType,
IList<Guid> referenceIds,
bool invert = false)
{
return baseQuery.Where(ReferencedItemFilterExpressionBuilder(context, itemValueType, referenceIds, invert));
}
/// <summary>
/// Builds a query that checks referenced ItemValues for a cross BaseItem lookup.
/// </summary>
/// <param name="baseQuery">The source query.</param>
/// <param name="context">The database context.</param>
/// <param name="itemValueTypes">The type of item value to reference.</param>
/// <param name="referenceIds">The list of BaseItem ids to check matches.</param>
/// <param name="invert">If set an exclusion check is performed instead.</param>
/// <returns>A Query.</returns>
public static IQueryable<BaseItemEntity> WhereReferencedItemMultipleTypes(
this IQueryable<BaseItemEntity> baseQuery,
JellyfinDbContext context,
IList<ItemValueType> itemValueTypes,
IList<Guid> referenceIds,
bool invert = false)
{
var itemFilter = OneOrManyExpressionBuilder<BaseItemEntity, Guid>(referenceIds, f => f.Id);
var typeFilter = OneOrManyExpressionBuilder<ItemValue, ItemValueType>(itemValueTypes, iv => iv.Type);
return baseQuery.Where(item =>
context.ItemValues
.Where(typeFilter)
.Join(context.ItemValuesMap, e => e.ItemValueId, e => e.ItemValueId, (itemVal, map) => new { itemVal, map })
.Any(val =>
context.BaseItems.Where(itemFilter).Any(e => e.CleanName == val.itemVal.CleanValue)
&& val.map.ItemId == item.Id) == EF.Constant(!invert));
}
/// <summary>
/// Builds a query expression that checks referenced ItemValues for a cross BaseItem lookup.
/// </summary>
/// <param name="context">The database context.</param>
/// <param name="itemValueType">The type of item value to reference.</param>
/// <param name="referenceIds">The list of BaseItem ids to check matches.</param>
/// <param name="invert">If set an exclusion check is performed instead.</param>
/// <returns>A Query.</returns>
public static Expression<Func<BaseItemEntity, bool>> ReferencedItemFilterExpressionBuilder(
this JellyfinDbContext context,
ItemValueType itemValueType,
IList<Guid> referenceIds,
bool invert = false)
{
// Well genre/artist/album etc items do not actually set the ItemValue of thier specitic types so we cannot match it that way.
/*
"(guid in (select itemid from ItemValues where CleanValue = (select CleanName from TypedBaseItems where guid=@GenreIds and Type=2)))"
*/
var itemFilter = OneOrManyExpressionBuilder<BaseItemEntity, Guid>(referenceIds, f => f.Id);
return item =>
context.ItemValues
.Join(context.ItemValuesMap, e => e.ItemValueId, e => e.ItemValueId, (item, map) => new { item, map })
.Any(val =>
val.item.Type == itemValueType
&& context.BaseItems.Where(itemFilter).Any(e => e.CleanName == val.item.CleanValue)
&& val.map.ItemId == item.Id) == EF.Constant(!invert);
}
/// <summary>
/// Filters items that match any of the specified (provider name, value) pairs.
/// </summary>
/// <param name="baseQuery">The source query.</param>
/// <param name="providerIds">Dictionary mapping provider names to arrays of values to match.</param>
/// <returns>A filtered query.</returns>
public static IQueryable<BaseItemEntity> WhereHasAnyProviderIds(
this IQueryable<BaseItemEntity> baseQuery,
IReadOnlyDictionary<string, string[]> providerIds)
{
var providerKeys = providerIds
.SelectMany(kvp => kvp.Value.Select(v => $"{kvp.Key}:{v}"))
.ToList();
if (providerKeys.Count == 0)
{
return baseQuery;
}
return baseQuery.Where(e => e.Provider!.Any(p => providerKeys.Contains(p.ProviderId + ":" + p.ProviderValue)));
}
/// <summary>
/// Filters items that have any of the specified providers. Empty/null values match any value for that provider.
/// </summary>
/// <param name="baseQuery">The source query.</param>
/// <param name="providerIds">Dictionary mapping provider names to optional values.</param>
/// <returns>A filtered query.</returns>
public static IQueryable<BaseItemEntity> WhereHasAnyProviderId(
this IQueryable<BaseItemEntity> baseQuery,
IReadOnlyDictionary<string, string> providerIds)
{
var existenceOnly = providerIds
.Where(e => string.IsNullOrEmpty(e.Value))
.Select(e => e.Key)
.ToList();
var specificValues = providerIds
.Where(e => !string.IsNullOrEmpty(e.Value))
.Select(e => $"{e.Key}:{e.Value}")
.ToList();
if (existenceOnly.Count == 0 && specificValues.Count == 0)
{
return baseQuery;
}
if (existenceOnly.Count == 0)
{
return baseQuery.Where(e => e.Provider!.Any(p =>
specificValues.Contains(p.ProviderId + ":" + p.ProviderValue)));
}
if (specificValues.Count == 0)
{
return baseQuery.Where(e => e.Provider!.Any(p => existenceOnly.Contains(p.ProviderId)));
}
// Single EXISTS over Provider with both predicates OR'd, instead of two separate subqueries.
return baseQuery.Where(e => e.Provider!.Any(p =>
existenceOnly.Contains(p.ProviderId) ||
specificValues.Contains(p.ProviderId + ":" + p.ProviderValue)));
}
/// <summary>
/// Excludes items that match any of the specified (provider name, value) pairs.
/// </summary>
/// <param name="baseQuery">The source query.</param>
/// <param name="providerIds">Dictionary mapping provider names to values to exclude.</param>
/// <returns>A filtered query.</returns>
public static IQueryable<BaseItemEntity> WhereExcludeProviderIds(
this IQueryable<BaseItemEntity> baseQuery,
IReadOnlyDictionary<string, string> providerIds)
{
var excludeKeys = providerIds
.Select(e => $"{e.Key}:{e.Value}")
.ToList();
if (excludeKeys.Count == 0)
{
return baseQuery;
}
return baseQuery.Where(e => e.Provider!.All(p => !excludeKeys.Contains(p.ProviderId + ":" + p.ProviderValue)));
}
/// <summary>
/// Builds an optimised query expression checking one property against a list of values while maintaining an optimal query.
/// </summary>
/// <typeparam name="TEntity">The entity.</typeparam>
/// <typeparam name="TProperty">The property type to compare.</typeparam>
/// <param name="oneOf">The list of items to check.</param>
/// <param name="property">Property expression.</param>
/// <returns>A Query.</returns>
public static Expression<Func<TEntity, bool>> OneOrManyExpressionBuilder<TEntity, TProperty>(this IList<TProperty> oneOf, Expression<Func<TEntity, TProperty>> property)
{
var parameter = Expression.Parameter(typeof(TEntity), "item");
property = ParameterReplacer.Replace<Func<TEntity, TProperty>, Func<TEntity, TProperty>>(property, property.Parameters[0], parameter);
if (oneOf.Count == 1)
{
var value = oneOf[0];
if (typeof(TProperty).IsValueType)
{
return Expression.Lambda<Func<TEntity, bool>>(Expression.Equal(property.Body, Expression.Constant(value)), parameter);
}
else
{
return Expression.Lambda<Func<TEntity, bool>>(Expression.ReferenceEqual(property.Body, Expression.Constant(value)), parameter);
}
}
var containsMethodInfo = _containsQueryCache.GetOrAdd(typeof(TProperty), static (key) => _containsMethodGenericCache.MakeGenericMethod(key));
// Threshold picked from microbenchmarks on SQLite: inline IN(const,...) beats a
// parameterized array lookup by ~5-10% up to ~32 elements.
if (oneOf.Count <= 32)
{
return Expression.Lambda<Func<TEntity, bool>>(Expression.Call(null, containsMethodInfo, Expression.Constant(oneOf), property.Body), parameter);
}
return Expression.Lambda<Func<TEntity, bool>>(Expression.Call(null, containsMethodInfo, Expression.Call(null, _efParameterInstruction.MakeGenericMethod(oneOf.GetType()), Expression.Constant(oneOf)), property.Body), parameter);
}
internal static class ParameterReplacer
{
// Produces an expression identical to 'expression'
// except with 'source' parameter replaced with 'target' expression.
internal static Expression<TOutput> Replace<TInput, TOutput>(
Expression<TInput> expression,
ParameterExpression source,
ParameterExpression target)
{
return new ParameterReplacerVisitor<TOutput>(source, target)
.VisitAndConvert(expression);
}
private sealed class ParameterReplacerVisitor<TOutput> : ExpressionVisitor
{
private readonly ParameterExpression _source;
private readonly ParameterExpression _target;
public ParameterReplacerVisitor(ParameterExpression source, ParameterExpression target)
{
_source = source;
_target = target;
}
internal Expression<TOutput> VisitAndConvert<T>(Expression<T> root)
{
return (Expression<TOutput>)VisitLambda(root);
}
protected override Expression VisitLambda<T>(Expression<T> node)
{
// Leave all parameters alone except the one we want to replace.
var parameters = node.Parameters.Select(p => p == _source ? _target : p);
return Expression.Lambda<TOutput>(Visit(node.Body), parameters);
}
protected override Expression VisitParameter(ParameterExpression node)
{
// Replace the source with the target, visit other params as usual.
return node == _source ? _target : base.VisitParameter(node);
}
}
}
}