Android /data空间小

在手机安装应用时，系统会自动在/data/data目录下面以应用的主包名创建一个目录，默认还会在最后的那个目录里面创建一个lib目录。下面看一下系统获取存储空间的代码：

 

来自android2.3.3系统源代码/packages/apps/Settings/src/com/android/settings/applications/ManageApplications.java

 

 

531.mDataFileStats = new StatFs("/data"); 

532.mSDCardFileStats = new StatFs(Environment.getExternalStorageDirectory().toString()); 

 

<pre name="code" class="java">748.mDataFileStats.restat("/data"); 

            try { 

                totalStorage = (long)mDataFileStats.getBlockCount() * 

                        mDataFileStats.getBlockSize(); 

                freeStorage = (long) mDataFileStats.getAvailableBlocks() * 

                    mDataFileStats.getBlockSize(); 

            } catch (IllegalArgumentException e) { 

            } 

            final int N = mApplicationsAdapter.getCount(); 

            for (int i=0; i<N; i++) { 

                ApplicationsState.AppEntry ae = mApplicationsAdapter.getAppEntry(i); 

                appStorage += ae.codeSize + ae.dataSize; 

            } 

            freeStorage += mApplicationsState.sumCacheSizes();<pre name="code" class="java"><pre> 

 

734.mSDCardFileStats.restat(Environment.getExternalStorageDirectory().toString()); 

try { 

    totalStorage = (long)mSDCardFileStats.getBlockCount() * mSDCardFileStats.getBlockSize(); 

    freeStorage = (long) mSDCardFileStats.getAvailableBlocks() * mSDCardFileStats.getBlockSize(); 

} catch (IllegalArgumentException e) { 

    // use the old value of mFreeMem 

}

 

第531行代码是/data目录下面的空间，第532行是检查SD卡的空间。

 

“存储空间不足”data过小的通知分析DeviceStorageMonitorService类

位置

DeviceStorageMonitorService.java (frameworks\base\services\java\com\android\server\)

一. 三个关键变量:

private static final int DEFAULT_THRESHOLD_PERCENTAGE = 10;
private static final int DEFAULT_FULL_THRESHOLD_BYTES = 1*1024*1024; // 1MB
private static final long DEFAULT_DISK_FREE_CHANGE_REPORTING_THRESHOLD = 2 * 1024 * 1024; // 2MB

二. 参数调用的地方
在整个android目录中, 三个常量被调用的地方, 都只是在DeviceStorageMonitorService.java中

DEFAULT_THRESHOLD_PERCENTAGE(10) : private long getMemThreshold();
return 1300234 * 10 = 13,002,340

DEFAULT_FULL_THRESHOLD_BYTES(10M) : private int getMemFullThreshold()
return 10,485,760

DEFAULT_DISK_FREE_CHANGE_REPORTING_THRESHOLD(5M=5,242,880) : private final void restatDataDir();
threshold = 5,242,880 delta = mFreeMem = 101,482,696

三. 函数被调用的地方
DeviceStorageMonitorService构造中

private long mMemLowThreshold = getMemThreshold();

四. DeviceStorageMonitorService的调用追踪

private final void checkMemory(boolean checkCache) -> 判断() ->
private final void sendNotification()

在sendNotification()中将剩余内存的值存入intent中, 然后广播出去, 广播类型为ACTION_MANAGE_PACKAGE_STORAGE
此通知的标题为 “存储空间不足(Low on space)”
通知的内容为 “手机内存空间所剩不多了(Phone storage space is getting low)”

五. DEFAULT_FULL_THRESHOLD_BYTES的调用追踪

private final void checkMemory(boolean checkCache) -> 判断() ->
private final void sendFullNotification() ->
sendStickyBroadcast(intent.ACTION_DEVICE_STORAGE_FULL)

若data目录小于DEFAULT_FULL_THRESHOLD_BYTES, 则不在接收短信.

六. DEFAULT_DISK_FREE_CHANGE_REPORTING_THRESHOLD 调用追踪

private final void checkMemory(boolean checkCache) ->
EventLog.writeEvent(EventLogTags.FREE_STORAGE_CHANGED, mFreeMem)

经过jwisp烧录到真机上发现, 真正有可能有用的是百分比报警, 那只需要设置下面这个参数即可:
DEFAULT_THRESHOLD_PERCENTAGE

转载自 <a href="http://www.jwisp.com/?p=97" title="“存储空间不足”data过小的通知分析DeviceStorageMonitorService类" rel="bookmark">“存储空间不足”data过小的通知分析DeviceStorageMonitorService类 | 卓派</a>