Performance issue with Volley's DiskBasedCache

Question

In my Photo Collage app for Android I\'m using Volley for loading images. I\'m using the DiskBasedCache (included with volley) with 50 mb storage to prevent re-downloading

Answer 1

Yes, the way DiskBasedCache works it needs to open all the files in initialize(). Which is simply.... not a good idea :-(

You need to make a different implementation that doesent open all the files at startup.

Take a copy of DiskBasedCache and change initialize() to

  @Override
  public synchronized void initialize() {
    if (!mRootDirectory.exists()) {
      if (!mRootDirectory.mkdirs()) {
        VolleyLog.e("Unable to create cache dir %s", mRootDirectory.getAbsolutePath());
      }
    }
  }

And change get() so it makes an additional check for if the file exists on the file system, like

  @Override
  public synchronized Entry get(String key) {
    CacheHeader entry = mEntries.get(key);
    File file = getFileForKey(key);
    if (entry == null && !file.exists()) { // EXTRA CHECK
      // if the entry does not exist, return.
      VolleyLog.d("DrVolleyDiskBasedCache miss for " + key);
      return null;
    }
    ...

I use this approach in https://play.google.com/store/apps/details?id=dk.dr.radio and it works fine - its robustness have been tested by ~300000 users :-)

You can download a full version of the file from https://code.google.com/p/dr-radio-android/source/browse/trunk/DRRadiov3/src/dk/dr/radio/net/volley/DrDiskBasedCache.java (you'll have to delete some DR Radio specific stuff)