Hstore query support

Fixes npgsql#212

src/EFCore.PG/Query/ExpressionTranslators/Internal/NpgsqlHstoreTranslator.cs

@@ -0,0 +1,248 @@
+using System.Collections.Immutable;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Query.Expressions;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Query.Expressions.Internal;
+using static Npgsql.EntityFrameworkCore.PostgreSQL.Utilities.Statics;
+
+namespace Npgsql.EntityFrameworkCore.PostgreSQL.Query.ExpressionTranslators.Internal;
+
+/// <summary>
+///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+///     any release. You should only use it directly in your code with extreme caution and knowing that
+///     doing so can result in application failures when updating to a new Entity Framework Core release.
+/// </summary>
+public class NpgsqlHstoreTranslator : IMethodCallTranslator, IMemberTranslator
+{
+    private static readonly Type DictionaryType = typeof(Dictionary<string, string>);
+    private static readonly Type ImmutableDictionaryType = typeof(ImmutableDictionary<string, string>);
+
+    private static readonly MethodInfo Dictionary_ContainsKey =
+        DictionaryType.GetMethod(nameof(Dictionary<string, string>.ContainsKey))!;
+
+    private static readonly MethodInfo ImmutableDictionary_ContainsKey =
+        ImmutableDictionaryType.GetMethod(nameof(ImmutableDictionary<string, string>.ContainsKey))!;
+
+    private static readonly MethodInfo Dictionary_ContainsValue =
+        DictionaryType.GetMethod(nameof(Dictionary<string, string>.ContainsValue))!;
+
+    private static readonly MethodInfo ImmutableDictionary_ContainsValue =
+        ImmutableDictionaryType.GetMethod(nameof(ImmutableDictionary<string, string>.ContainsValue))!;
+
+    private static readonly MethodInfo Dictionary_Item_Getter =
+        DictionaryType.FindIndexerProperty()!.GetMethod!;
+
+    private static readonly MethodInfo ImmutableDictionary_Item_Getter =
+        ImmutableDictionaryType.FindIndexerProperty()!.GetMethod!;
+
+    private static readonly MethodInfo Enumerable_Any =
+        typeof(Enumerable).GetMethod(
+                nameof(Enumerable.Any), BindingFlags.Public | BindingFlags.Static,
+                [typeof(IEnumerable<>).MakeGenericType(Type.MakeGenericMethodParameter(0))])!
+            .MakeGenericMethod(typeof(KeyValuePair<string, string>));
+
+    private static readonly MethodInfo Enumerable_ToList =
+        typeof(Enumerable).GetMethod(
+                nameof(Enumerable.ToList), BindingFlags.Public | BindingFlags.Static,
+                [typeof(IEnumerable<>).MakeGenericType(Type.MakeGenericMethodParameter(0))])!
+            .MakeGenericMethod(typeof(string));
+
+    private static readonly MethodInfo Enumerable_ToDictionary =
+        typeof(Enumerable).GetMethod(
+            nameof(Enumerable.ToDictionary), BindingFlags.Public | BindingFlags.Static,
+            [
+                typeof(IEnumerable<>).MakeGenericType(
+                    typeof(KeyValuePair<,>).MakeGenericType(Type.MakeGenericMethodParameter(0), Type.MakeGenericMethodParameter(1)))
+            ])!.MakeGenericMethod(typeof(string), typeof(string));
+
+    private static readonly MethodInfo ImmutableDictionary_ToImmutableDictionary =
+        typeof(ImmutableDictionary).GetMethod(
+            nameof(ImmutableDictionary.ToImmutableDictionary), BindingFlags.Public | BindingFlags.Static,
+            [
+                typeof(IEnumerable<>).MakeGenericType(
+                    typeof(KeyValuePair<,>).MakeGenericType(Type.MakeGenericMethodParameter(0), Type.MakeGenericMethodParameter(1)))
+            ])!.MakeGenericMethod(typeof(string), typeof(string));
+
+    private static readonly MethodInfo Enumerable_Concat = typeof(Enumerable).GetMethod(
+        nameof(Enumerable.Concat), BindingFlags.Public | BindingFlags.Static,
+        [
+            typeof(IEnumerable<>).MakeGenericType(Type.MakeGenericMethodParameter(0)),
+            typeof(IEnumerable<>).MakeGenericType(Type.MakeGenericMethodParameter(0))
+        ])!.MakeGenericMethod(typeof(KeyValuePair<string, string>));
+
+    private static readonly PropertyInfo Dictionary_Count = DictionaryType.GetProperty(nameof(Dictionary<string, string>.Count))!;
+
+    private static readonly PropertyInfo ImmutableDictionary_Count =
+        ImmutableDictionaryType.GetProperty(nameof(ImmutableDictionary<string, string>.Count))!;
+
+    private static readonly PropertyInfo ImmutableDictionary_IsEmpty =
+        ImmutableDictionaryType.GetProperty(nameof(ImmutableDictionary<string, string>.IsEmpty))!;
+
+    private static readonly PropertyInfo Dictionary_Keys = DictionaryType.GetProperty(nameof(Dictionary<string, string>.Keys))!;
+
+    private static readonly PropertyInfo ImmutableDictionary_Keys =
+        ImmutableDictionaryType.GetProperty(nameof(ImmutableDictionary<string, string>.Keys))!;
+
+    private static readonly PropertyInfo Dictionary_Values = DictionaryType.GetProperty(nameof(Dictionary<string, string>.Values))!;
+
+    private static readonly PropertyInfo ImmutableDictionary_Values =
+        ImmutableDictionaryType.GetProperty(nameof(ImmutableDictionary<string, string>.Values))!;
+
+    private readonly RelationalTypeMapping _stringListTypeMapping;
+    private readonly RelationalTypeMapping _stringTypeMapping;
+    private readonly RelationalTypeMapping _dictionaryMapping;
+    private readonly RelationalTypeMapping _immutableDictionaryMapping;
+    private readonly NpgsqlSqlExpressionFactory _sqlExpressionFactory;
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     any release. You should only use it directly in your code with extreme caution and knowing that
+    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+    /// </summary>
+    public NpgsqlHstoreTranslator(IRelationalTypeMappingSource typeMappingSource, NpgsqlSqlExpressionFactory sqlExpressionFactory)
+    {
+        _sqlExpressionFactory = sqlExpressionFactory;
+        _stringListTypeMapping = typeMappingSource.FindMapping(typeof(List<string>))!;
+        _stringTypeMapping = typeMappingSource.FindMapping(typeof(string))!;
+        _dictionaryMapping = typeMappingSource.FindMapping(DictionaryType)!;
+        _immutableDictionaryMapping = typeMappingSource.FindMapping(ImmutableDictionaryType)!;
+    }
+
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     any release. You should only use it directly in your code with extreme caution and knowing that
+    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+    /// </summary>
+    public SqlExpression? Translate(
+        SqlExpression? instance,
+        MethodInfo method,
+        IReadOnlyList<SqlExpression> arguments,
+        IDiagnosticsLogger<DbLoggerCategory.Query> logger)
+    {
+        if (instance is null)
+        {
+            if (arguments.Count is 2)
+            {
+                if (method == Enumerable_Concat
+                    && arguments[0].TypeMapping?.StoreType == "hstore"
+                    && arguments[1].TypeMapping?.StoreType == "hstore")
+                {
+                    return _sqlExpressionFactory.MakePostgresBinary(
+                        PgExpressionType.HStoreConcat, arguments[0], arguments[1], arguments[1].TypeMapping);
+                }
+
+                return null;
+            }
+
+            if (arguments.Count is not 1)
+            {
+                return null;
+            }
+
+            if (arguments[0].TypeMapping?.StoreType == "hstore")
+            {
+                if (method == Enumerable_Any)
+                {
+                    return _sqlExpressionFactory.NotEqual(Count(arguments[0]), _sqlExpressionFactory.Constant(0));
+                }
+
+                if (method == Enumerable_ToDictionary)
+                {
+                    return arguments[0].Type == ImmutableDictionaryType
+                        ? _sqlExpressionFactory.Convert(arguments[0], DictionaryType, _dictionaryMapping)
+                        : arguments[0];
+                }
+
+                if (method == ImmutableDictionary_ToImmutableDictionary)
+                {
+                    return arguments[0].Type == DictionaryType
+                        ? _sqlExpressionFactory.Convert(arguments[0], ImmutableDictionaryType, _immutableDictionaryMapping)
+                        : arguments[0];
+                }
+
+                return null;
+            }
+
+            if (method == Enumerable_ToList && arguments[0] is SqlFunctionExpression { Arguments: [{ TypeMapping.StoreType: "hstore" }] })
+            {
+                return arguments[0];
+            }
+
+            return null;
+        }
+
+        if (instance.TypeMapping?.StoreType != "hstore")
+        {
+            return null;
+        }
+
+        if (method == Dictionary_ContainsKey || method == ImmutableDictionary_ContainsKey)
+        {
+            return _sqlExpressionFactory.MakePostgresBinary(PgExpressionType.HStoreContainsKey, instance, arguments[0]);
+        }
+
+        if (method == Dictionary_ContainsValue || method == ImmutableDictionary_ContainsValue)
+        {
+            return _sqlExpressionFactory.Any(arguments[0], Values(instance), PgAnyOperatorType.Equal);
+        }
+
+        if (method == Dictionary_Item_Getter || method == ImmutableDictionary_Item_Getter)
+        {
+            return _sqlExpressionFactory.MakePostgresBinary(PgExpressionType.HStoreValueForKey, instance, arguments[0], _stringTypeMapping);
+        }
+
+        return null;
+    }
+
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     any release. You should only use it directly in your code with extreme caution and knowing that
+    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+    /// </summary>
+    public SqlExpression? Translate(
+        SqlExpression? instance,
+        MemberInfo member,
+        Type returnType,
+        IDiagnosticsLogger<DbLoggerCategory.Query> logger)
+    {
+
+        if (instance?.TypeMapping?.StoreType != "hstore")
+        {
+            return null;
+        }
+
+        if (member == Dictionary_Count || member == ImmutableDictionary_Count)
+        {
+            return Count(instance, true);
+        }
+
+        if (member == Dictionary_Keys || member == ImmutableDictionary_Keys)
+        {
+            return Keys(instance);
+        }
+
+        if (member == Dictionary_Values || member == ImmutableDictionary_Values)
+        {
+            return Values(instance);
+        }
+
+        if (member == ImmutableDictionary_IsEmpty)
+        {
+            return _sqlExpressionFactory.Equal(Count(instance), _sqlExpressionFactory.Constant(0));
+        }
+
+        return null;
+    }
+
+    private SqlExpression Keys(SqlExpression instance)
+        => _sqlExpressionFactory.Function(
+            "akeys", [instance], true, TrueArrays[1], typeof(List<string>), _stringListTypeMapping);
+
+    private SqlExpression Values(SqlExpression instance)
+        => _sqlExpressionFactory.Function(
+            "avals", [instance], true, TrueArrays[1], typeof(List<string>), _stringListTypeMapping);
+
+    private SqlExpression Count(SqlExpression instance, bool nullable = false)
+        => _sqlExpressionFactory.Function("cardinality", [Keys(instance)], nullable, TrueArrays[1], typeof(int));
+}

src/EFCore.PG/Query/ExpressionTranslators/Internal/NpgsqlMemberTranslatorProvider.cs

@@ -43,7 +43,8 @@ public NpgsqlMemberTranslatorProvider(
                 JsonPocoTranslator,
                 new NpgsqlRangeTranslator(typeMappingSource, sqlExpressionFactory, model, supportsMultiranges),
                 new NpgsqlStringMemberTranslator(sqlExpressionFactory),
-                new NpgsqlTimeSpanMemberTranslator(sqlExpressionFactory)
+                new NpgsqlTimeSpanMemberTranslator(sqlExpressionFactory),
+                new NpgsqlHstoreTranslator(typeMappingSource, sqlExpressionFactory)
         ]);
     }
 }

src/EFCore.PG/Query/ExpressionTranslators/Internal/NpgsqlMethodCallTranslatorProvider.cs

@@ -61,7 +61,8 @@ public NpgsqlMethodCallTranslatorProvider(
                 new NpgsqlRegexIsMatchTranslator(sqlExpressionFactory),
                 new NpgsqlRowValueTranslator(sqlExpressionFactory),
                 new NpgsqlStringMethodTranslator(typeMappingSource, sqlExpressionFactory),
-                new NpgsqlTrigramsMethodTranslator(typeMappingSource, sqlExpressionFactory, model)
+                new NpgsqlTrigramsMethodTranslator(typeMappingSource, sqlExpressionFactory, model),
+                new NpgsqlHstoreTranslator(typeMappingSource, sqlExpressionFactory)
         ]);
     }
 }

src/EFCore.PG/Query/Expressions/Internal/PgBinaryExpression.cs

@@ -151,6 +151,10 @@ protected override void Print(ExpressionPrinter expressionPrinter)
 
                     PgExpressionType.Distance => "<->",
 
+                    PgExpressionType.HStoreContainsKey => "?",
+                    PgExpressionType.HStoreValueForKey => "->",
+                    PgExpressionType.HStoreConcat => "||",
+
                     _ => throw new ArgumentOutOfRangeException($"Unhandled operator type: {OperatorType}")
                 })
             .Append(" ");

src/EFCore.PG/Query/Expressions/PgExpressionType.cs

@@ -159,4 +159,23 @@ public enum PgExpressionType
     LTreeFirstMatches, // ?~ or ?@
 
     #endregion LTree
+
+    #region HStore
+
+    /// <summary>
+    ///     Represents a PostgreSQL operator for checking if a hstore contains the given key
+    /// </summary>
+    HStoreContainsKey, // ?
+
+    /// <summary>
+    ///     Represents a PostgreSQL operator for accessing a hstore value for a given key
+    /// </summary>
+    HStoreValueForKey, // ->
+
+    /// <summary>
+    ///     Represents a PostgreSQL operator for concatenating hstores
+    /// </summary>
+    HStoreConcat, // ||
+
+    #endregion HStore
 }

src/EFCore.PG/Query/Internal/NpgsqlQuerySqlGenerator.cs

@@ -527,6 +527,10 @@ when binaryExpression.Left.TypeMapping is NpgsqlInetTypeMapping or NpgsqlCidrTyp
 
                     PgExpressionType.Distance => "<->",
 
+                    PgExpressionType.HStoreContainsKey => "?",
+                    PgExpressionType.HStoreValueForKey => "->",
+                    PgExpressionType.HStoreConcat => "||",
+
                     _ => throw new ArgumentOutOfRangeException($"Unhandled operator type: {binaryExpression.OperatorType}")
                 })
             .Append(" ");

src/EFCore.PG/Query/NpgsqlSqlExpressionFactory.cs

@@ -307,6 +307,7 @@ public virtual SqlExpression MakePostgresBinary(
             case PgExpressionType.JsonExists:
             case PgExpressionType.JsonExistsAny:
             case PgExpressionType.JsonExistsAll:
+            case PgExpressionType.HStoreContainsKey:
                 returnType = typeof(bool);
                 break;
 
@@ -773,6 +774,7 @@ private SqlExpression ApplyTypeMappingOnPostgresBinary(
             case PgExpressionType.JsonExists:
             case PgExpressionType.JsonExistsAny:
             case PgExpressionType.JsonExistsAll:
+            case PgExpressionType.HStoreContainsKey:
             {
                 // TODO: For networking, this probably needs to be cleaned up, i.e. we know where the CIDR and INET are
                 // based on operator type?
@@ -823,6 +825,17 @@ when left.Type.FullName is "NodaTime.Instant" or "NodaTime.LocalDateTime" or "No
                 break;
             }
 
+            case PgExpressionType.HStoreValueForKey:
+            case PgExpressionType.HStoreConcat:
+            {
+                return new PgBinaryExpression(
+                    operatorType,
+                    ApplyDefaultTypeMapping(left),
+                    ApplyDefaultTypeMapping(right),
+                    typeMapping!.ClrType,
+                    typeMapping);
+            }
+
             default:
                 throw new InvalidOperationException(
                     $"Incorrect {nameof(operatorType)} for {nameof(pgBinaryExpression)}: {operatorType}");

src/EFCore.PG/Storage/Internal/Mapping/NpgsqlHstoreTypeMapping.cs

@@ -5,7 +5,7 @@ namespace Npgsql.EntityFrameworkCore.PostgreSQL.Storage.Internal.Mapping;
 
 /// <summary>
 ///     The type mapping for the PostgreSQL hstore type. Supports both <see cref="Dictionary{TKey,TValue} " />
-///     and <see cref="ImmutableDictionary{TKey,TValue}" /> over strings.
+///     and <see cref="ImmutableDictionary{TKey,TValue}" /> where TKey and TValue are both strings.
 /// </summary>
 /// <remarks>
 ///     See: https://www.postgresql.org/docs/current/static/hstore.html