forked from BigfootDev/flatbuffers
5a95b7b6bc
* Offical Swift port for FlexBuffers This is the offical port for FlexBuffers within swift, and it introcudes a Common Module where code is shared between flatbuffers and flexbuffers. Writing most supported values like maps, vectors, nil and scalars into a flexbuffer buffer. And includes tests to verify that its similar to cpp * Reading a flexbuffer Implementing reading from a flexbuffer, enabling most of the buffers features, like most types, maps, vectors, typedvectors, and fixedtypedvectors. Currently, if an offset/object cant be read we default to a swift nil instead of the default flexbuffers 'null' with all values. * Fixes bazel breaking due to new project structure Address warnings within the library * Adds comment on why we added the code & properly enforce the amout of bytes needed
138 lines
3.0 KiB
Swift
138 lines
3.0 KiB
Swift
/*
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* Copyright 2024 Google Inc. All rights reserved.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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import Foundation
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public struct Value: Equatable {
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@usableFromInline
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enum Union: Equatable {
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case i(Int64)
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case u(UInt64)
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case f(Double)
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}
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var sloc: Union
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let type: FlexBufferType
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let bitWidth: BitWidth
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@inline(__always)
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private init() {
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sloc = .i(0)
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type = .null
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bitWidth = .w8
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}
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@inline(__always)
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init(bool: Bool) {
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sloc = .u(bool ? 1 : 0)
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type = .bool
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bitWidth = .w8
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}
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@inline(__always)
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init(v: UInt64, type: FlexBufferType, bitWidth: BitWidth) {
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sloc = .u(v)
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self.type = type
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self.bitWidth = bitWidth
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}
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@inline(__always)
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init(v: Int64, type: FlexBufferType, bitWidth: BitWidth) {
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sloc = .i(v)
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self.type = type
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self.bitWidth = bitWidth
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}
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@inline(__always)
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init(v: Double, type: FlexBufferType, bitWidth: BitWidth) {
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sloc = .f(v)
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self.type = type
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self.bitWidth = bitWidth
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}
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@inline(__always)
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init(sloc: Union, type: FlexBufferType, bitWidth: BitWidth) {
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self.sloc = sloc
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self.type = type
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self.bitWidth = bitWidth
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}
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@usableFromInline
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var i: Int64 {
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switch sloc {
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case .i(let v): v
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default: 0
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}
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}
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@usableFromInline
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var u: UInt64 {
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switch sloc {
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case .u(let v): v
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default: 0
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}
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}
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@usableFromInline
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var f: Double {
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switch sloc {
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case .f(let v): v
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default: 0
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}
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}
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static let `nil` = Value()
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}
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extension Value {
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@usableFromInline
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@inline(__always)
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func elementWidth(size: Int, index: UInt64) -> BitWidth {
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if isInline(type) {
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return bitWidth
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} else {
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for byteWidth in stride(from: 1, to: MemoryLayout<UInt64>.size, by: 2) {
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let _offsetLoc: UInt64 = numericCast(numericCast(size) &+ padding(
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bufSize: numericCast(size),
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elementSize: numericCast(byteWidth)))
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let offsetLoc = _offsetLoc &+ (index &* numericCast(byteWidth))
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let offset = offsetLoc &- u
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let bitWidth = widthU(offset)
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if (UInt32.one << bitWidth.rawValue) == byteWidth {
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return bitWidth
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}
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}
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return .w64
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}
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}
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@inline(__always)
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func storedPackedType(width: BitWidth = .w8) -> UInt8 {
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packedType(bitWidth: storedWidth(width: width), type: type)
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}
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@inline(__always)
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private func storedWidth(width: BitWidth) -> BitWidth {
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if isInline(type) {
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return max(bitWidth, width)
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} else {
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return bitWidth
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}
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}
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}
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