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 /// Mutable is a protocol that allows us to mutate Scalar values within a ``ByteBuffer`` 24 public protocol Mutable { 25 /// makes Flatbuffer accessed within the Protocol 26 var bb: ByteBuffer { get } 27 /// makes position of the ``Table``/``struct`` accessed within the Protocol 28 var postion: Int32 { get } 29 } 30 31 extension Mutable { 32 33 /// Mutates the memory in the buffer, this is only called from the access function of ``Table`` and ``struct`` 34 /// - Parameters: 35 /// - value: New value to be inserted to the buffer 36 /// - index: index of the Element mutate<T: Scalar>null37 func mutate<T: Scalar>(value: T, o: Int32) -> Bool { 38 guard o != 0 else { return false } 39 bb.write(value: value, index: Int(o), direct: true) 40 return true 41 } 42 } 43 44 extension Mutable where Self == Table { 45 46 /// Mutates a value by calling mutate with respect to the position in a ``Table`` 47 /// - Parameters: 48 /// - value: New value to be inserted to the buffer 49 /// - index: index of the Element mutate<T: Scalar>null50 public func mutate<T: Scalar>(_ value: T, index: Int32) -> Bool { 51 guard index != 0 else { return false } 52 return mutate(value: value, o: index + postion) 53 } 54 55 /// Directly mutates the element by calling mutate 56 /// 57 /// Mutates the Element at index ignoring the current position by calling mutate 58 /// - Parameters: 59 /// - value: New value to be inserted to the buffer 60 /// - index: index of the Element directMutate<T: Scalar>null61 public func directMutate<T: Scalar>(_ value: T, index: Int32) -> Bool { 62 mutate(value: value, o: index) 63 } 64 } 65 66 extension Mutable where Self == Struct { 67 68 /// Mutates a value by calling mutate with respect to the position in the struct 69 /// - Parameters: 70 /// - value: New value to be inserted to the buffer 71 /// - index: index of the Element mutate<T: Scalar>null72 public func mutate<T: Scalar>(_ value: T, index: Int32) -> Bool { 73 mutate(value: value, o: index + postion) 74 } 75 76 /// Directly mutates the element by calling mutate 77 /// 78 /// Mutates the Element at index ignoring the current position by calling mutate 79 /// - Parameters: 80 /// - value: New value to be inserted to the buffer 81 /// - index: index of the Element directMutate<T: Scalar>null82 public func directMutate<T: Scalar>(_ value: T, index: Int32) -> Bool { 83 mutate(value: value, o: index) 84 } 85 } 86 87 extension Struct: Mutable {} 88 extension Table: Mutable {} 89