XCLogParser, SwitUI primeras impresiones

During the first part of this talk, Erick Camacho (#spotify #engineer), tells us about the #XCLogParser project focused on obtaining everything you need to know about Xcode's hidden logs

In the second part of the talk, the hosts, Abdiel Soto(@abdielsba), Gandhi Mena(@gandhimena), Iván Alvarez(@ivanhoe) talk about their first impressions regarding the launch of #SwfitUI days after it was launched

Transcript

1. All you need to know about Xcode hidden logs Erick Camacho (@ecamacho)
2. About me iOS Infrastructure Engineer @Spotify
3. Agenda • The format - The tooling This is a story about a journey full of mistery and marvels inside Xcode
4. Xcode build report
5. Xcode test report
6. That's great if there is only one developer in the team
7. But what if we want to get the data outside Xcode?
8. In Android world (using gradle) is possible
11. There should be way to do it for Xcode
12. First clue: There is a log! Thanks @micheletitolo https://michele.io/test-logs-in-xcode
14. Where? DerivedData/Project/Logs/Build DerivedData/Project/Logs/Test
15. When? A few seconds after a build / test finishes
16. What's inside?
17. The LogStoreManifest • List of existing xcactivitylog files in the directory • Some basic data: name of the project, build time, etc.
18. The xcactivitylog file An .xcactivitylog is a gzipped file
19. What's inside the Gzip? A Serialized log using the SLF format.
20. And what's the SLF format?
21. Second clue: The SLF Format Thank you @vincentisambart https://techlife.cookpad.com/entry/2017/12/08/124532 (In japanese)
22. SLF Xcode's very own undocumented serialization format.
23. SLF files start with the SLF0 header
24. The rest of the content is a collection of these types: Integer Array Double Class name nil Class instance String
25. Encoding Each types is encoded as value + type delimiter + optional value
26. Integers Type delimiter: # Example: 10# • Tip: You will need an Int64 to store it
27. Double Type delimiter: ^ Example: afd021ebae48c141^ • Tip: The double is encoded in Hexadecimal • Tip: Used to store Dates (timeIntervalSince1970)
28. Nil Type delimiter: - Example: - • Tip: No left hand side value
29. String Type delimiter: " Example: 5"Hello • Tip: The left hand integer is the length of the String. • Tip: Count the chars after the delimiter.
30. Array Type delimiter: ( Example: 12( • Tip: The left hand side value indicates the number of elements in the List.
31. Class name Type delimiter: % Example: 21%IDEActivityLogSection • Tip: The left hand value is the length of the name • Tip: The right hand value is the name of the Class.
32. Class instance Type delimiter: @ Example: 0#
33. Class instance The value is the index of the Class name of the instance's type. Everytime you find a Class name you assign an index to it. The left hand value of a Class instance is that index. All the values after a Class reference may be attributes of the class instance.
34. We can tokenize logs!
35. SLF010#21%IDEActivityLogSection1@0#39"Xcode.IDEActivityL ogDomainType.BuildLog20"Build XCLogParserApp20"Build XCLogParserApp0074f8eaae48c141^8f19bcf4ae48c141^12(1 @1#50"Xcode.IDEActivityLogDomainType.XCBuild.Preparation 13"Prepare build13"Prepare buildafd021ebae48c141^66a248ebae48c141^-
36. [type: int, value: 10], [type: className, name: "IDEActivityLogSection"], [type: classNameRef, className: "IDEActivityLogSection"], [type: int, value: 0], [type: string, value: "Xcode.IDEActivityLogDomainType.BuildLog"], [type: string, value: "Build XCLogParserApp"], [type: string, value: "Build XCLogParserApp"], [type: double, value: 580158292.767495], [type: double, value: 580158295.086277], [type: list, count: 11], [type: classNameRef, className: "IDEActivityLogSection"], [type: int, value: 1], [type: string, value: "Xcode.IDEActivityLogDomainType.XCBuild.Preparation"], [type: string, value: "Prepare build"], [type: string, value: "Prepare build"], [type: double, value: 580158292.82973], [type: double, value: 580158292.853954], [type: nil]
37. How can you deserialize the classes?
38. List the Class names found in the logs • IDEActivityLogSection • IDEActivityLogUnitTestSection • IDEActivityLogMessage • DVTDocumentLocation • DVTTextDocumentLocation
39. Third clue: They are part of the IDEFoundation.framework Thanks to @luisobo https://github.com/luisobo/Xcode-RuntimeHeaders
40. You can use the same technique to class dump the current Xcode headers
41. It's time to build a parser
42. 1. Start with a Class 2. Get the N tokens after the Class instance (Where N is the number of properties in the Header file) 3. Assign those tokens to instance variables. Criteria: type, order 4. When in doubt: get more logs 5. Repeat
43. XCLogParser A Swift command line tool for parsing Xcode logs.
44. Demo
45. Dump
46. Dumps the content of an .xcactivitylog into a JSON document
47. We have a lot of data but not that well organized
48. Back to the board
49. We built a parser Demo
52. The Parse command returns the most significant data.
53. We built some useful reporters on top of it
54. JSON Array xclogparser parse --project xclogparser --report flatJson
55. Chrome Tracer xclogparser parse --project xclogparser \ --reporter chromeTracer \ --output xclogparser_chrome.json
56. Chrome Tracer
57. HTML xclogparser parse --project xclogparser \ --reporter html \ --output reports
58. HTML
59. Errors TODO: screenshot of an error report
60. Warnings TODO: screenshot of the warnings section
61. Build times TODO: screenshot of the build times section
62. Get it now https://github.com/spotify/ xclogparser
63. Use cases • In your CI to generate build time artifacts. • Benchmark build times • Locally to diagnose build problems.
64. Use cases • To gatekeep Pull Request that introduce new warnings • To analyze how parallelized your builds are and improve them. • To gatekeep Pull Request that introduce longer build times.
65. We need your help • Give it a try, the more logs we can try it with, the better • Contribute!
66. Thank you XCLogParser's team Me (Erick Camacho) @ecamacho Patrick Balestra @BalestraPatrick Hassan Belhabib Anton Lazarev