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Exploring Facebook's iOS Client - The FBSessionGKs Section探索 Facebook iOS 客户端 - Section FBSessionGKs
· Performance & internals
Translated from Chinese — .
Observation
Viewing Facebook’s executable with MachOView, I found the FBInjectable and fbsessiongks data sections. This article explores the creation and purpose of the fbsessiongks data section.
Creation
Refer to the previous article about FBInjectable.
Initial Exploration
Part of fbsessiongks’s content is as follows:
@["ios_share_extension_hashtags_enabled","ios_share_extension_mentions_disabled","ios_share_extension_360_upload_enabled","ios_share_extension_delegate_cleanup","ios_hemingway_limit_sections","aldrin_qr_code_experiment","ios_set_badge_count_on_init","ios_side_feed_show_newsfeed_units_gk","fb_app_zero_rating","fb_app_zero_rating_bad_url_errors","ios_zero_rating_header_request","ios_checkpoints_logged_in_blocking","uber_app_integration","nearby_friends_self_view","ios_nearby_friends_dashboard_invite","ios_nf_replace_pls_with_message","ios_nearby_friends_profile_style","nearby_friends_dashboard_checkins_hometown","nearby_friends_self_view","ios_nearby_friends_dashboard_reaction","ios_friends_nearby_bookmark_alert","ios_friends_nearby_bookmark_upsell","ios_nearby_friends_inv
....省略...
Simple Conclusion
Experimental feature switches. gks is short for Gate Keepers. Used to assist testing.
A Facebook engineer mentioned Gate Keepers: (search the article for gate keeper) https://www.facebook.com/notes/facebook-engineering/building-and-testing-at-facebook/10151004157328920/
Unlike FBInjectable, the features here are all experimental and are all just BOOL types (FBInjectable has concrete configuration features and can provide detailed parameter values). There’s a dedicated FBExperimentManager class to manage, collect statistics, and report various logs.
Related Methods
void * +[FBFeatureGatingConfigFactory applicationSpecificFeatureGatingConfig](void * self, void * _cmd) {
+[FBExperimentGatekeepers allSessionGatekeeperKeys]
+[FBExperimentManager _getSupportedConfigurationsFromPolicy:]:
-[FBExperimentManager initWithPolicy:experimentDiskFetcher:jsonOverrides:mobileConfigContextManager:]:
Summary
The specific exploration process is similar to the previous article Exploring Facebook’s iOS Client - The FBInjectable Section
I’ll add a Demo when I have time.
现象
MachOView查看Facebook的可执行文件，发现 FBInjectable 和 fbsessiongks 的数据段，这篇文章就探索下 fbsessiongks 数据段的产生与用途。
产生
参考上一篇关于FBInjectable的文章。
初步探索
fbsessiongks的部分内容如下：
@["ios_share_extension_hashtags_enabled","ios_share_extension_mentions_disabled","ios_share_extension_360_upload_enabled","ios_share_extension_delegate_cleanup","ios_hemingway_limit_sections","aldrin_qr_code_experiment","ios_set_badge_count_on_init","ios_side_feed_show_newsfeed_units_gk","fb_app_zero_rating","fb_app_zero_rating_bad_url_errors","ios_zero_rating_header_request","ios_checkpoints_logged_in_blocking","uber_app_integration","nearby_friends_self_view","ios_nearby_friends_dashboard_invite","ios_nf_replace_pls_with_message","ios_nearby_friends_profile_style","nearby_friends_dashboard_checkins_hometown","nearby_friends_self_view","ios_nearby_friends_dashboard_reaction","ios_friends_nearby_bookmark_alert","ios_friends_nearby_bookmark_upsell","ios_nearby_friends_inv
....省略...
简单结论
实验性质的功能开关。gks 为 Gate Keepers 缩写。为了辅助测试。
Facebook 员工提到Gate Keepers：（文章中搜索gate keeper） https://www.facebook.com/notes/facebook-engineering/building-and-testing-at-facebook/10151004157328920/
与FBInjectable不同的是，这里的功能都是具有实验性质，且都只是BOOL类型（FBInjectable是有具体的配置功能，可提供详细的参数数值）。有专门的FBExperimentManager类管理、统计、上报各种日志。
相关方法
void * +[FBFeatureGatingConfigFactory applicationSpecificFeatureGatingConfig](void * self, void * _cmd) {
+[FBExperimentGatekeepers allSessionGatekeeperKeys]
+[FBExperimentManager _getSupportedConfigurationsFromPolicy:]:
-[FBExperimentManager initWithPolicy:experimentDiskFetcher:jsonOverrides:mobileConfigContextManager:]:
总结
具体探索过程类似上一篇文章 探索 Facebook iOS 客户端 - Section FBInjectable
Demo有时间再补充啦