damus

nostr ios client
git clone git://jb55.com/damus
Log | Files | Refs | README | LICENSE

Message.swift (2296B)


      1 /*
      2  * Copyright 2023 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 }