chore: import upstream snapshot with attribution

server/pg_provider.go

@@ -0,0 +1,79 @@
+// Copyright 2026 Dolthub, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package server
+
+import (
+	"github.com/dolthub/dolt/go/libraries/doltcore/sqle"
+	"github.com/dolthub/dolt/go/libraries/doltcore/sqle/dsess"
+	"github.com/dolthub/dolt/go/libraries/utils/filesys"
+	"github.com/dolthub/go-mysql-server/sql"
+
+	"github.com/dolthub/doltgresql/server/tables"
+)
+
+// DoltgresDatabaseProvider wraps DoltDatabaseProvider to enforce PostgreSQL specific
+// requirements, such as requiring all relation names (e.g. tables, indexes, sequences, views)
+// are unique within a schema.
+type DoltgresDatabaseProvider struct {
+	*sqle.DoltDatabaseProvider
+}
+
+var _ sql.DatabaseProvider = (*DoltgresDatabaseProvider)(nil)
+
+// Database overrides DoltDatabaseProvider.Database to wrap the returned sql.Database
+// with PgDatabase, enabling relation-name uniqueness enforcement.
+func (p *DoltgresDatabaseProvider) Database(ctx *sql.Context, name string) (sql.Database, error) {
+	db, err := p.DoltDatabaseProvider.Database(ctx, name)
+	if err != nil {
+		return nil, err
+	}
+	return tables.WrapSqlDatabase(db), nil
+}
+
+// AllDatabases overrides DoltDatabaseProvider.AllDatabases to wrap each returned database
+// with PgDatabase so that AllSchemas returns properly wrapped schemas (including pg_catalog
+// virtual-table schemas) regardless of which code path iterates the catalog.
+func (p *DoltgresDatabaseProvider) AllDatabases(ctx *sql.Context) []sql.Database {
+	all := p.DoltDatabaseProvider.AllDatabases(ctx)
+	for i, db := range all {
+		all[i] = tables.WrapSqlDatabase(db)
+	}
+	return all
+}
+
+// UnderlyingDoltProvider implements sqle.DoltProviderUnwrapper so that NewSqlEngine can
+// access the wrapped *DoltDatabaseProvider for Dolt-specific configuration.
+func (p *DoltgresDatabaseProvider) UnderlyingDoltProvider() *sqle.DoltDatabaseProvider {
+	return p.DoltDatabaseProvider
+}
+
+// DoltgresProviderFactory is the ProviderFactory for Doltgres. It embeds DoltProviderFactory
+// and overrides NewProvider to wrap the result in DoltgresDatabaseProvider, so that
+// Database() returns PgDatabase-wrapped databases enforcing PostgreSQL relation-name uniqueness.
+type DoltgresProviderFactory struct {
+	sqle.DoltProviderFactory
+}
+
+var _ sqle.ProviderFactory = DoltgresProviderFactory{}
+
+// NewProvider overrides DoltProviderFactory.NewProvider to wrap the created provider in
+// DoltgresDatabaseProvider before returning it.
+func (f DoltgresProviderFactory) NewProvider(defaultBranch string, fs filesys.Filesys, databases []dsess.SqlDatabase, locations []filesys.Filesys, overrides sql.EngineOverrides) (sql.DatabaseProvider, error) {
+	inner, err := f.DoltProviderFactory.NewProvider(defaultBranch, fs, databases, locations, overrides)
+	if err != nil {
+		return nil, err
+	}
+	return &DoltgresDatabaseProvider{inner.(*sqle.DoltDatabaseProvider)}, nil
+}