Add Sendable checking (#242)

Author: fabianfett

Sources/PostgresNIO/Connection/PostgresConnection.swift

@@ -566,3 +566,7 @@ private extension String {
         }
     }
 }
+
+#if swift(>=5.6)
+extension PostgresConnection: @unchecked Sendable {}
+#endif

Sources/PostgresNIO/Data/PostgresData.swift

@@ -1,4 +1,8 @@
+#if swift(>=5.6)
+@preconcurrency import NIOCore
+#else
 import NIOCore
+#endif
 import Foundation
 
 public struct PostgresData: CustomStringConvertible, CustomDebugStringConvertible {
@@ -112,3 +116,7 @@ extension PostgresData: PostgresDataConvertible {
         return self
     }
 }
+
+#if swift(>=5.6)
+extension PostgresData: Sendable {}
+#endif

Sources/PostgresNIO/Data/PostgresDataType.swift

@@ -17,6 +17,11 @@ extension PostgresFormat: CustomStringConvertible {
     }
 }
 
+#if swift(>=5.6)
+extension PostgresFormat: Sendable {}
+#endif
+
+
 // TODO: The Codable conformance does not make any sense. Let's remove this with next major break.
 extension PostgresFormat: Codable {}
 
@@ -233,6 +238,10 @@ public struct PostgresDataType: RawRepresentable, Hashable, CustomStringConverti
     }
 }
 
+#if swift(>=5.6)
+extension PostgresDataType: Sendable {}
+#endif
+
 // TODO: The Codable conformance does not make any sense. Let's remove this with next major break.
 extension PostgresDataType: Codable {}
 

Sources/PostgresNIO/Data/PostgresRow.swift

@@ -1,4 +1,8 @@
+#if swift(>=5.6)
+@preconcurrency import NIOCore
+#else
 import NIOCore
+#endif
 import class Foundation.JSONDecoder
 
 /// `PostgresRow` represents a single table row that is received from the server for a query or a prepared statement.
@@ -311,3 +315,11 @@ extension PostgresRow: CustomStringConvertible {
         return row.description
     }
 }
+
+#if swift(>=5.6)
+extension PostgresRow: Sendable {}
+
+extension PostgresRandomAccessRow: Sendable {}
+#endif
+
+

Sources/PostgresNIO/New/Messages/RowDescription.swift

@@ -76,3 +76,7 @@ struct RowDescription: PostgresBackendMessage.PayloadDecodable, Equatable {
         return RowDescription(columns: result)
     }
 }
+
+#if swift(>=5.6)
+extension RowDescription.Column: Sendable {}
+#endif

Sources/PostgresNIO/New/PSQLRowStream.swift

@@ -396,3 +396,8 @@ protocol PSQLRowsDataSource {
     func cancel(for stream: PSQLRowStream)
 
 }
+
+#if swift(>=5.6)
+// Thread safety is guaranteed in the RowStream through dispatching onto the NIO EventLoop.
+extension PSQLRowStream: @unchecked Sendable {}
+#endif

Sources/PostgresNIO/New/PostgresCell.swift

@@ -1,4 +1,8 @@
+#if swift(>=5.6)
+@preconcurrency import NIOCore
+#else
 import NIOCore
+#endif
 
 public struct PostgresCell: Equatable {
     public var bytes: ByteBuffer?
@@ -49,3 +53,7 @@ extension PostgresCell {
         }
     }
 }
+
+#if swift(>=5.6)
+extension PostgresCell: Sendable {}
+#endif