Add support for Postgres inet type

Sources/PostgresNIO/New/Data/SocketAddress+PostgresCodable.swift

@@ -0,0 +1,86 @@
+import NIOCore
+
+extension SocketAddress: PostgresDecodable {
+    public init<JSONDecoder: PostgresJSONDecoder>(from byteBuffer: inout NIOCore.ByteBuffer, type: PostgresDataType, format: PostgresFormat, context: PostgresDecodingContext<JSONDecoder>) throws {
+        // IP family
+        byteBuffer.moveReaderIndex(forwardBy: MemoryLayout<UInt8>.size)
+
+        // netmask length in bits
+        guard let netmaskLength: UInt8 = byteBuffer.readInteger(as: UInt8.self) else {
+            throw PostgresDecodingError.Code.failure
+        }
+
+        // ensure it is not a CIDR
+        guard byteBuffer.readInteger(as: UInt8.self) == 0 else {
+            throw PostgresDecodingError.Code.failure
+        }
+
+        // address length in bytes
+        guard let addressLength: UInt8 = byteBuffer.readInteger(as: UInt8.self),
+            addressLength * 8 == netmaskLength,
+            let packedIPAddress: ByteBuffer = byteBuffer.readSlice(length: Int(addressLength))
+        else {
+            throw PostgresDecodingError.Code.failure
+        }
+
+        try self.init(packedIPAddress: packedIPAddress, port: 0)
+    }
+}
+
+extension SocketAddress: PostgresEncodable & PostgresNonThrowingEncodable {
+    public static var psqlType: PostgresDataType { return .inet }
+    public static var psqlFormat: PostgresFormat { .binary }
+    public func encode<JSONEncoder: PostgresJSONEncoder>(into byteBuffer: inout ByteBuffer, context: PostgresEncodingContext<JSONEncoder>) {
+        switch self {
+        case .v4(let address):
+            // IP family
+            byteBuffer.writeInteger(UInt8(2))
+            // netmask length in bits
+            byteBuffer.writeInteger(UInt8(32))
+            // indicate it is not a CIDR
+            byteBuffer.writeInteger(UInt8(0))
+            // address length in bytes
+            byteBuffer.writeInteger(UInt8(4))
+            // address values
+            let addressBytes = withUnsafeBytes(of: address.address.sin_addr.s_addr) { Array($0) }
+            byteBuffer.writeBytes(addressBytes)
+
+        case .v6(let address):
+            // IP family
+            byteBuffer.writeInteger(UInt8(3))
+            // netmask length in bits
+            byteBuffer.writeInteger(UInt8(128))
+            // indicate it is not a CIDR
+            byteBuffer.writeInteger(UInt8(0))
+            // address length in bytes
+            byteBuffer.writeInteger(UInt8(16))
+            // address values
+            let addressBytes = withUnsafeBytes(of: address.address.sin6_addr) { Array($0) }
+            byteBuffer.writeBytes(addressBytes)
+
+        case .unixDomainSocket:
+            fatalError("Cannot encode a UNIX socket address using the Postgres inet type")
+        }
+    }
+}
+
+extension SocketAddress: PostgresArrayDecodable {}
+
+extension SocketAddress: PostgresArrayEncodable {
+    public static var psqlArrayType: PostgresDataType { return .inetArray }
+}
+
+extension SocketAddress: Decodable {
+    public init(from decoder: Decoder) throws {
+        let container = try decoder.singleValueContainer()
+        let ipAddress = try container.decode(String.self)
+        try self.init(ipAddress: ipAddress, port: 0)
+    }
+}
+
+extension SocketAddress: Encodable {
+    public func encode(to encoder: Encoder) throws {
+        var container = encoder.singleValueContainer()
+        try container.encode(self.description)
+    }
+}