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copied!<p>According to my benchmarks, that code should easily be able to perform way better than 120 kb/s (I'm running on different hardware, but still).</p> <p>If you profile the code with <a href="http://developer.android.com/guide/developing/debugging/debugging-tracing.html" rel="nofollow">Traceview</a>, where is the time spent? If the bottleneck is FileInputStream.read(), think about:</p> <ul> <li>if some other app is using the sdcard at the same time as you, like a media indexing app or something. Sharing bandwidth with some other app will have an adverse effect on the sdcard reading performance of your app.</li> <li>If the sdcard itself is the problem. Try another sdcard or re-format the one you have.</li> </ul> <p>If the bottleneck is MessageDigest.update() (which I doubt), I guess you do need to look into a JNI solution. For your information, the SHA-1 implementation already is in native code (see <a href="https://github.com/android/platform_frameworks_base/blob/21e6e2de1f0062f949fcc52d0b4559dfa3246e0e/core/jni/android_message_digest_sha1.cpp" rel="nofollow">android_message_digest_sha1.cpp</a>), but maybe you can gain a speedup by avoiding some native <-> Java copying.</p> <p><strong>Update 1 (Please ignore):</strong></p> <p>(Based on your profiling, the problem seems to be that you don't use Android's optimized <code>android.security.MessageDigest</code> but instead <code>java.security.MessageDigest</code>. Try <code>android.security.MessageDigest</code> instead. Both Android 2.2 and 2.3 have native SHA-1 implementations of <code>android.security.MessageDigest</code>.)</p> <p><strong>Update 2:</strong></p> <p>Sorry, I forgot about <code>android.security.MessageDigest</code> being internal. I now realize that I was also using <code>java.security.MessageDigest</code> in my benchmarking. I was running on Android 2.3 though, and it turns out the SHA-1 implementation of <code>java.security.MessageDigest</code> in Android 2.3 is in native code as well, while that appearently is not the case on Android 2.2.</p> <p>So the answer to your original question is: Yes, it is painfully slow in Android 2.2 due to a Java implementation but significantly faster in Android 2.3 due to an implementation in native code. You should see similar speedups on Android 2.2 if you use your own SHA-1 implementation in native code.</p>

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