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 import Foundation 18 19 /// Mutable is a protocol that allows us to mutate Scalar values within the buffer 20 public protocol Mutable { 21 /// makes Flatbuffer accessed within the Protocol 22 var bb: ByteBuffer { get } 23 /// makes position of the table/struct accessed within the Protocol 24 var postion: Int32 { get } 25 } 26 27 extension Mutable { 28 29 /// Mutates the memory in the buffer, this is only called from the access function of table and structs 30 /// - Parameters: 31 /// - value: New value to be inserted to the buffer 32 /// - index: index of the Element mutate<T: Scalar>null33 func mutate<T: Scalar>(value: T, o: Int32) -> Bool { 34 guard o != 0 else { return false } 35 bb.write(value: value, index: Int(o), direct: true) 36 return true 37 } 38 } 39 40 extension Mutable where Self == Table { 41 42 /// Mutates a value by calling mutate with respect to the position in the table 43 /// - Parameters: 44 /// - value: New value to be inserted to the buffer 45 /// - index: index of the Element mutate<T: Scalar>null46 public func mutate<T: Scalar>(_ value: T, index: Int32) -> Bool { 47 guard index != 0 else { return false } 48 return mutate(value: value, o: index + postion) 49 } 50 51 /// Directly mutates the element by calling mutate 52 /// 53 /// Mutates the Element at index ignoring the current position by calling mutate 54 /// - Parameters: 55 /// - value: New value to be inserted to the buffer 56 /// - index: index of the Element directMutate<T: Scalar>null57 public func directMutate<T: Scalar>(_ value: T, index: Int32) -> Bool { 58 mutate(value: value, o: index) 59 } 60 } 61 62 extension Mutable where Self == Struct { 63 64 /// Mutates a value by calling mutate with respect to the position in the struct 65 /// - Parameters: 66 /// - value: New value to be inserted to the buffer 67 /// - index: index of the Element mutate<T: Scalar>null68 public func mutate<T: Scalar>(_ value: T, index: Int32) -> Bool { 69 mutate(value: value, o: index + postion) 70 } 71 72 /// Directly mutates the element by calling mutate 73 /// 74 /// Mutates the Element at index ignoring the current position by calling mutate 75 /// - Parameters: 76 /// - value: New value to be inserted to the buffer 77 /// - index: index of the Element directMutate<T: Scalar>null78 public func directMutate<T: Scalar>(_ value: T, index: Int32) -> Bool { 79 mutate(value: value, o: index) 80 } 81 } 82 83 extension Struct: Mutable {} 84 extension Table: Mutable {} 85