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DiskStatsService.javaAPI DocAndroid 5.1 API3793Thu Mar 12 22:22:42 GMT 2015com.android.server

DiskStatsService

public class DiskStatsService extends android.os.Binder
This service exists only as a "dumpsys" target which reports statistics about the status of the disk.

Fields Summary
private static final String
TAG
private final android.content.Context
mContext
Constructors Summary
public DiskStatsService(android.content.Context context)


       
        mContext = context;
Methods Summary
protected voiddump(java.io.FileDescriptor fd, java.io.PrintWriter pw, java.lang.String[] args)

        mContext.enforceCallingOrSelfPermission(android.Manifest.permission.DUMP, TAG);

        // Run a quick-and-dirty performance test: write 512 bytes
        byte[] junk = new byte[512];
        for (int i = 0; i < junk.length; i++) junk[i] = (byte) i;  // Write nonzero bytes

        File tmp = new File(Environment.getDataDirectory(), "system/perftest.tmp");
        FileOutputStream fos = null;
        IOException error = null;

        long before = SystemClock.uptimeMillis();
        try {
            fos = new FileOutputStream(tmp);
            fos.write(junk);
        } catch (IOException e) {
            error = e;
        } finally {
            try { if (fos != null) fos.close(); } catch (IOException e) {}
        }

        long after = SystemClock.uptimeMillis();
        if (tmp.exists()) tmp.delete();

        if (error != null) {
            pw.print("Test-Error: ");
            pw.println(error.toString());
        } else {
            pw.print("Latency: ");
            pw.print(after - before);
            pw.println("ms [512B Data Write]");
        }

        reportFreeSpace(Environment.getDataDirectory(), "Data", pw);
        reportFreeSpace(Environment.getDownloadCacheDirectory(), "Cache", pw);
        reportFreeSpace(new File("/system"), "System", pw);

        // TODO: Read /proc/yaffs and report interesting values;
        // add configurable (through args) performance test parameters.
private voidreportFreeSpace(java.io.File path, java.lang.String name, java.io.PrintWriter pw)

        try {
            StatFs statfs = new StatFs(path.getPath());
            long bsize = statfs.getBlockSize();
            long avail = statfs.getAvailableBlocks();
            long total = statfs.getBlockCount();
            if (bsize <= 0 || total <= 0) {
                throw new IllegalArgumentException(
                        "Invalid stat: bsize=" + bsize + " avail=" + avail + " total=" + total);
            }

            pw.print(name);
            pw.print("-Free: ");
            pw.print(avail * bsize / 1024);
            pw.print("K / ");
            pw.print(total * bsize / 1024);
            pw.print("K total = ");
            pw.print(avail * 100 / total);
            pw.println("% free");
        } catch (IllegalArgumentException e) {
            pw.print(name);
            pw.print("-Error: ");
            pw.println(e.toString());
            return;
        }