1 /* 2 * Copyright 2021 Google Inc. All rights reserved. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #if !os(WASI) 18 import Foundation 19 #else 20 import SwiftOverlayShims 21 #endif 22 23 /// FlatBufferGRPCMessage protocol that should allow us to invoke 24 /// initializers directly from the GRPC generated code 25 public protocol FlatBufferGRPCMessage { 26 27 /// Raw pointer which would be pointing to the beginning of the readable bytes 28 var rawPointer: UnsafeMutableRawPointer { get } 29 30 /// Size of readable bytes in the buffer 31 var size: Int { get } 32 33 init(byteBuffer: ByteBuffer) 34 } 35 36 /// Message is a wrapper around Buffers to to able to send Flatbuffers `Buffers` through the 37 /// GRPC library 38 public struct Message<T: FlatBufferObject>: FlatBufferGRPCMessage { 39 internal var buffer: ByteBuffer 40 41 /// Returns the an object of type T that would be read from the buffer 42 public var object: T { 43 T.init( 44 buffer, 45 o: Int32(buffer.read(def: UOffset.self, position: buffer.reader)) + 46 Int32(buffer.reader)) 47 } 48 49 public var rawPointer: UnsafeMutableRawPointer { 50 buffer.memory.advanced(by: buffer.reader) } 51 52 public var size: Int { Int(buffer.size) } 53 54 /// Initializes the message with the type Flatbuffer.Bytebuffer that is transmitted over 55 /// GRPC 56 /// - Parameter byteBuffer: Flatbuffer ByteBuffer object 57 public init(byteBuffer: ByteBuffer) { 58 buffer = byteBuffer 59 } 60 61 /// Initializes the message by copying the buffer to the message to be sent. 62 /// from the builder 63 /// - Parameter builder: FlatbufferBuilder that has the bytes created in 64 /// - Note: Use `builder.finish(offset)` before passing the builder without prefixing anything to it 65 public init(builder: inout FlatBufferBuilder) { 66 buffer = builder.sizedBuffer 67 builder.clear() 68 } 69 } 70