Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Working With Binary Data in Swift
Search
JP Simard
October 29, 2015
Programming
4
1.2k
Working With Binary Data in Swift
Presented at Swift Summit SF 2015.
Source available here:
https://github.com/jpsim/talks
JP Simard
October 29, 2015
Tweet
Share
More Decks by JP Simard
See All by JP Simard
Unconventional Swift Patterns
jpsim
0
210
Pushing Envoy Beyond the Edge
jpsim
0
30
Lessons from Mobile Networking at Scale
jpsim
0
45
Bespoke, Artisanal Swift Static Analysis
jpsim
2
1.6k
Performance Profiling Swift on Linux
jpsim
4
1.4k
Realm Mobile Platform Experience
jpsim
3
100
"Watch Your Language!": The road to clean code with SwiftLint
jpsim
6
78k
Mastering Realm Notifications
jpsim
1
34k
Realm 1.0 Party
jpsim
1
97
Other Decks in Programming
See All in Programming
ローコードサービスの進化のためのモノレポ移行
taro28
1
340
remix + cloudflare workers (DO) docker上でいい感じに開発する
yoshidatomoaki
0
120
AtCoder Heuristic First-step Vol.1 講義スライド(山登り法・焼きなまし法編)
takumi152
3
990
Coding Experience Cpp vs Csharp - meetup app osaka@9
harukasao
0
120
Kubernetesで実現できるPlatform Engineering の現在地
nwiizo
2
1.7k
複数ドメインに散らばってしまった画像…! 運用中のPHPアプリに後からCDNを導入する…!
suguruooki
0
430
ニックトレイン登壇資料
ryotakurokawa
0
140
エンジニア未経験が最短で戦力になるためのTips
gokana
0
220
MCP世界への招待: AIエンジニアが創る次世代エージェント連携の世界
gunta
2
590
リアクティブシステムの変遷から理解するalien-signals / Learning alien-signals from the evolution of reactive systems
yamanoku
2
1k
英語 × の私が、生成AIの力を借りて、OSSに初コントリビュートした話
personabb
0
100
Preact、HooksとSignalsの両立 / Preact: Harmonizing Hooks and Signals
ssssota
1
740
Featured
See All Featured
Code Review Best Practice
trishagee
67
18k
Rebuilding a faster, lazier Slack
samanthasiow
80
8.9k
Responsive Adventures: Dirty Tricks From The Dark Corners of Front-End
smashingmag
251
21k
CSS Pre-Processors: Stylus, Less & Sass
bermonpainter
356
30k
The Illustrated Children's Guide to Kubernetes
chrisshort
48
49k
Statistics for Hackers
jakevdp
798
220k
Docker and Python
trallard
44
3.3k
Facilitating Awesome Meetings
lara
53
6.3k
GraphQLとの向き合い方2022年版
quramy
45
14k
A Philosophy of Restraint
colly
203
16k
How GitHub (no longer) Works
holman
314
140k
Principles of Awesome APIs and How to Build Them.
keavy
126
17k
Transcript
Working with Binary Data in Swift
JP Simard @ Realm
None
Options → NSData → [UInt8] → withUnsafePointer() → ???
Layout-Aligned Structs
func encode<T>(var value: T) -> NSData { return withUnsafePointer(&value) {
p in NSData(bytes: p, length: sizeofValue(value)) } } func decode<T>(data: NSData) -> T { let pointer = UnsafeMutablePointer<T>.alloc(sizeof(T)) data.getBytes(pointer, length: sizeof(T)) return pointer.move() }
enum Either<T> { case Left(T) case Right(T) } let value
= Either.Left("Swift Summit") let data = encode(value) data // => <NSData> let decoded: Either<String> = decode(data) decoded // => Either.Left("Swift Summit")
None
None
Get SourceKit syntax map struct A { subscript(index: Int) ->
() { return () } }
Result 00 00 00 00 00 00 00 00 30
00 00 00 00 00 00 00 40 4c 81 01 01 00 00 00 00 00 00 00 0c 00 00 00 78 4c 81 01 01 00 00 00 07 00 00 00 14 00 00 00 b0 4c 81 01 01 00 00 00 12 00 00 00 1e 00 00 00 00
Result 00 00 00 00 00 00 00 00 30
00 00 00 00 00 00 00 --------16 bytes------- --------16 bytes------- 40 4c 81 01 01 00 00 00 00 00 00 00 0c 00 00 00 --------16 bytes------- --------16 bytes------- 78 4c 81 01 01 00 00 00 07 00 00 00 14 00 00 00 --------16 bytes------- --------16 bytes------- b0 4c 81 01 01 00 00 00 12 00 00 00 1e 00 00 00 --------16 bytes------- --------16 bytes------- 00
!
struct SyntaxToken { let type: String let offset: Int let
length: Int }
Strideable
tokens = 16.stride(through: numberOfTokens * 16, by: 16).map { parserOffset
in . }
tokens = 16.stride(through: numberOfTokens * 16, by: 16).map { parserOffset
in var uid = UInt64(0), offset = 0, length = 0 data.getBytes(&uid, range: NSRange(location: parserOffset, length: 8)) data.getBytes(&offset, range: NSRange(location: 8 + parserOffset, length: 4)) data.getBytes(&length, range: NSRange(location: 12 + parserOffset, length: 4)) }
tokens = 16.stride(through: numberOfTokens * 16, by: 16).map { parserOffset
in var uid = UInt64(0), offset = 0, length = 0 data.getBytes(&uid, range: NSRange(location: parserOffset, length: 8)) data.getBytes(&offset, range: NSRange(location: 8 + parserOffset, length: 4)) data.getBytes(&length, range: NSRange(location: 12 + parserOffset, length: 4)) return SyntaxToken( type: stringForSourceKitUID(uid) ?? "unknown", offset: offset, length: length >> 1 ) }
Collection of Bytes → Making our own → Conforming to
ExtensibleCollectionType → What Index type should we use? Int?
Just end up with [UInt8]
Links → SourceKittenFramework SyntaxMap → Convert structs and enums to
NSData → robnapier.net/nsdata → Simon Lewis on parsing OLE/COM → github.com/realm/jazzy → realm.io
try! ask(...) struct Question { let value: String let canJPAnswer:
Bool } func ask<S: SequenceType where S.Generator.Element == Question>(questions: S) throws { // excercise for attendees }