iOS app's Documents and Data becomes huge

问题

I'm using admob mediation for ads on my applications. Normally my app's size is 40 mb, but my app's documents and data becomes 300+ mb.

I've noticed that my app's document and data becomes huge after using it regularly. I've made some investigation and I've recovered my app's documents and data (.xcappdata) using xcode. I've noticed that in AppData/Library/Preferences, there were duplicates files of my app default preferences. Some file named such as com.xxx.myappID.plist.ZHxFTUd. In order to view those files I've rename them as ZHxFTUd.com.xxx.myappID.plist. I've found out these were duplicated files, 70 duplicated files to be exact.

Upon opening those files there were some values like

<key> google_stats_ca-app-pub-myAdmobApplicationKey/qdata=AJ5UM1meQd-5Amf4Ji5BU4gJwMyuz2Vid36rPZwPHe2UK8cA-2Gef8xlTS99iBCjLdMzFWXul_sesDYhEMHFm_MskhDpFcfObGyF0nhVwrcpu_y72g&allocation_ids=8812023832745925 </key> 
<key> google_timing_ca-app-pub-myAdmobApplicationKey/qdata=AJ5UM1niK5ksaOVtdz3HP684pmOcF8gp6yQ_ElQkMYqVK0TVokgM7Hr-L4pYKx7PNGErHit2-WJ7YFFf9dhNnG-RSk0Dn7VFzzpt9LFm3VvavGDzhA&allocation_ids=8812023832745925 </key> 
<key> google_gad_use_https </key>.

Can someone give me some info about it. These duplicated files makes my app becomes huge.

I'm using 7.1.0 Google Mobile Ads SDK, deployment target ios 8.0. These problems occured in my two iPad running iOS 8.1 and iOS 8.3.

来源：https://stackoverflow.com/questions/29886513/ios-apps-documents-and-data-becomes-huge