How to speed up File Storage Access?

Question

I am trying to get a list of all Folders that contain MP3 Files on the user's Internal Storage.

Here is the recursive function that I am calling for this purpose -

public void listAllMusicFiles(String pathToDirectory) {
        String lastFolderPath = "";
        int mp3Count = 0;
        File f = new File(pathToDirectory);
        File[] files = f.listFiles();
        for (File inFile : files) {
            if (inFile.isDirectory()) {
                //reset last folder path
                lastFolderPath = "";
                Log.d("Directory ", inFile.getPath());
                listAllMusicFiles(inFile.getPath());
            } else {
                if (inFile.getAbsolutePath().endsWith(".mp3") || inFile.getAbsolutePath().endsWith(".MP3")) {
                    mp3Count++;
                    Log.wtf("MP3 Count", mp3Count + " ");

                    //add each folder only once
                    String folderName = inFile.getParentFile().getName();
                    String folderPath = inFile.getParentFile().getPath();
                    Log.e("FOUND in", folderPath);

                    //create a new Folder object
                    Folder currentFolder = new Folder(folderName, folderPath, mp3Count + "");

                    if (!lastFolderPath.equals(folderPath)) {
                        Log.d("NEW", folderPath);
                        lastFolderPath = folderPath;
                        folderArrayList.add(currentFolder);
                    } else {
                        Log.d("OLD", folderPath);
                        //find a Folder object in folderArrayList where the object's path matches current folderPath
                        for (Folder folder : folderArrayList) {
                            String currentPath = folder.getFolder_Path();
                            if (currentPath.equals(folderPath)) {
                                //found a match
                                //update count
                                folder.setFolder_Song_Count(mp3Count + "");
                            }
                        }
                    }
                }
            }
        }
    }

When I run this code on my device, I am able to list the required folders in a RecyclerView, but with a delay of about 6-7 seconds.

I have already moved this task into an AsyncTask, so that my UIThread does not hang because of this intensive operation.

But I am totally at a loss when it comes to improving File System Performance. Kindly help. Thanks !

' listAllMusicFiles(String pathToDirectory)'. You are converting back and fort between Sting and File. Make it 'listAllMusicFiles(File directory)'. — greenapps, Sep 29 '16 at 11:37
'folderName = inFile.getParentFile().getName();' That is 'f.getName();'. — greenapps, Sep 29 '16 at 11:40
When there are 100 mp3 files in a directory you 100 times iterate the array list to see if that folder is already there. And then you change the count for that folder a hundred times. That cannot be efficient. You should first count the files in that folder. And when done with that folder add name and count one time to the array. You dont have to check anything then. — greenapps, Sep 29 '16 at 11:53

score 0 · Accepted Answer · answered Sep 29 '16 at 11:38

Instead of storing currentFolder in an ArrayList and in the next step iterating through complete list to find that folder and updating the value, you can simply use HashMap like this

HashMap<String, Folder> folders = new HashMap<>();

    public void listAllMusicFiles(String pathToDirectory) {

        int mp3Count = 0;
        File f = new File(pathToDirectory);
        File[] files = f.listFiles();

        Folder folder;
        String folderName, folderPath;

        for (File inFile : files) {
            if (inFile.isDirectory()) {
                //reset last folder path
                Log.d("Directory ", inFile.getPath());
                listAllMusicFiles(inFile.getPath());
            } else {
                if (inFile.getAbsolutePath().endsWith(".mp3") || inFile.getAbsolutePath().endsWith(".MP3")) {
                    mp3Count++;
                    Log.wtf("MP3 Count", mp3Count + " ");

                    //add each folder only once
                    folderName = inFile.getParentFile().getName();
                    folderPath = inFile.getParentFile().getPath();

                    Log.e("FOUND in", folderPath);

                    if (folders.containsKey(folderPath)) {

                        folder = folders.get(folderPath);
                        folder.setFolder_Song_Count(mp3Count + "");
                        folders.put(folderPath, folder);
                    } else {

                        folder = new Folder(folderName, folderPath, mp3Count + "");
                        folders.put(folderPath, folder);
                    }

                }
            }
        }
    }

best for multimedia use MediaStore.. – D.J Sep 29 '16 at 11:40 — D.J, Sep 29 '16 at 11:40

How to speed up File Storage Access?

1 Answers1