Using cordova writeFile for a 20MB blob crashes (Android)

Question

I am trying to write a 20MB blob to file on an Android device. This code works fine for 4-5MB or so, but crashes for larger files.

tp = cordova.file.dataDirectory; // for Android $cordovaFile.writeFile(tp, "temp-file.gif", blob,true);

is there a way to handle larger blobs? thanks. I already have android:largeHeap="true" in the manifest.

the logcat error:

E/JavaBinder(  809): !!! FAILED BINDER TRANSACTION !!!
I/art     (  809): Background sticky concurrent mark sweep GC freed 62202(4MB) AllocSpace objects, 96(3MB) LOS objects, 20% free, 25MB/31MB, paused 20.488ms total 176.243ms
E/JavaBinder(  809): !!! FAILED BINDER TRANSACTION !!!
W/ActivityManager(  809): Exception thrown during pause
W/ActivityManager(  809): android.os.TransactionTooLargeException
W/ActivityManager(  809):   at android.os.BinderProxy.transactNative(Native Method)
W/ActivityManager(  809):   at android.os.BinderProxy.transact(Binder.java:496)
W/ActivityManager(  809):   at android.app.ApplicationThreadProxy.schedulePauseActivity(ApplicationThreadNative.java:711)
W/ActivityManager(  809):   at com.android.server.am.ActivityStack.startPausingLocked(ActivityStack.java:829)
W/ActivityManager(  809):   at com.android.server.am.ActivityStack.finishActivityLocked(ActivityStack.java:2749)
W/ActivityManager(  809):   at com.android.server.am.ActivityStack.finishTopRunningActivityLocked(ActivityStack.java:2606)
W/ActivityManager(  809):   at com.android.server.am.ActivityStackSupervisor.finishTopRunningActivityLocked(ActivityStackSupervisor.java:2544)
W/ActivityManager(  809):   at com.android.server.am.ActivityManagerService.handleAppCrashLocked(ActivityManagerService.java:11721)
W/ActivityManager(  809):   at com.android.server.am.ActivityManagerService.makeAppCrashingLocked(ActivityManagerService.java:11618)
W/ActivityManager(  809):   at com.android.server.am.ActivityManagerService.crashApplication(ActivityManagerService.java:12330)
W/ActivityManager(  809):   at com.android.server.am.ActivityManagerService.handleApplicationCrashInner(ActivityManagerService.java:11819)
W/ActivityManager(  809):   at com.android.server.am.NativeCrashListener$NativeCrashReporter.run(NativeCrashListener.java:86)

Answer 1

The solution, after experimentation is to break up the write into chunks - that seems to work for 20-30MB files that I've tested so far.

    function writeFile2( path, file, blob, isAppend)
    {
        var csize = 4 * 1024 * 1024; // 4MB
        var d = $q.defer();
        NVRDataModel.debug ("Inside writeFile2 with blob size="+blob.size);

        // nothing more to write, so all good?
        if (!blob.size)
        {
            NVRDataModel.debug ("writeFile2 all done");
            d.resolve(true);
            return $q.resolve(true); 
        }


        if (!isAppend)
           {
               // return the delegated promise, even if it fails
               return $cordovaFile.writeFile(path, file, blob.slice(0,csize), true)
                   .then (function (succ) {
                       return writeFile2(path,file,blob.slice(csize),true);
                   });
           }
           else
           {
               // return the delegated promise, even if it fails
               return $cordovaFile.writeExistingFile(path, file, blob.slice(0,csize))
                   .then (function (succ) {
                       return writeFile2(path,file,blob.slice(csize),true);
                   });   
           }


    }

Credit: @Andre Werlang helped me with this here: https://stackoverflow.com/a/40935231/1361529