Android Cache Partition

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Android Cache Partition

 

What means “Backup”？

Android's backup service allows you to copy your persistent application data to remote "cloud" storage, in order to provide a restore point for the application data and settings. If a user performs a factory reset or converts to a new Android-powered device, the system automatically restores your backup data when the application is re-installed. This way, your users don't need to reproduce their previous data or application settings. This process is completely transparent to the user and does not affect the functionality or user experience in your application.

How “Backup” works?

Settings->privacy->Back up my data

   We can enable “Backup” here.

When backupping,BackupManager copy app’s own files to /cache/backup/app_name

When restoring,BackupManager copy files back from /cache/backup/app_name

System apps who use “backup”:

   Settings, browser,inputmethod,userdictionary,

   Wallpapers, wifi service and backup native command---bmgr

The space “Backup” takes depends on size of app’s files.

What’sDownloadProvider？

Android内部提供了一个DownloadProvider，是一个非常完整的下载工具，提供了很好的外部接口可以被其他应用程序调用，来完成下载工作。同时也提供和很好的下载、通知、存储等机制。
在Android的Browser等工具里面都用到了这个DownloadProvider。

但是很遗憾的是，这个DownloadProvider不对app开发人员开放，只作为内部使用。

Market.apk 源码没有公开，推断使用了DownloadProvider进行app的下载