private Map<Album, Map<ImageType, Resource>> collectAlbumTargets(
Library library, final ResourceLocator resourceLocator, Collection<Album> changedAlbums) {
Map<Album, Map<ImageType, Resource>> result = new HashMap<>();
for (Album album : library.getAlbums()) {
Resource artworkAssetResource = album.artworkAssetResource();
if (artworkAssetResource != null) {
Map<ImageType, Resource> targets = new HashMap<ImageType, Resource>();
for (ImageType type : ImageType.values()) {
String imagePath = resourceLocator.getAlbumImagePath(album, type);
if (imagePath != null) {
Resource resource = resourceLocator.getResource(imagePath);
try {
if (changedAlbums.contains(album) || !resource.exists()) {
resource.getParent().mkdirs();
targets.put(type, resource);
}
} catch (IOException e) {
LOGGER.warning("Could not write image file: " + resource.getPath().toAbsolutePath());
}
}
}
if (!targets.isEmpty()) {
result.put(album, targets);
}
}
}
return result;
}
public void formatImages(
Library library,
ResourceLocator resourceLocator,
Collection<Album> changedAlbums,
int maxThreads,
final ProgressHandler progressHandler) {
if (progressHandler != null) {
progressHandler.beginTask(-1, "Preparing images...");
}
final Map<Album, Map<ImageType, Resource>> albumTargets =
collectAlbumTargets(library, resourceLocator, changedAlbums);
if (progressHandler != null) {
progressHandler.endTask();
}
List<Album> albums = new ArrayList<>(albumTargets.keySet());
int numberOfAlbumsPerTask = 10;
int numberOfAlbums = albums.size();
int numberOfThreads =
Math.min(
1 + (numberOfAlbums - 1) / numberOfAlbumsPerTask,
Math.min(maxThreads, Runtime.getRuntime().availableProcessors()));
if (progressHandler != null) {
progressHandler.beginTask(numberOfAlbums, "Formatting images...");
}
final int progressModulo = numberOfAlbums < 200 ? 10 : numberOfAlbums < 1000 ? 50 : 100;
if (numberOfThreads > 1) { // run on multiple threads
if (LOGGER.isLoggable(Level.FINER)) {
LOGGER.finer("Parallel: #threads = " + numberOfThreads);
}
ExecutorService executor = Executors.newFixedThreadPool(numberOfThreads);
final AtomicInteger atomicCount = new AtomicInteger();
for (int start = 0; start < numberOfAlbums; start += numberOfAlbumsPerTask) {
final Collection<Album> albumsSlice =
albums.subList(start, Math.min(numberOfAlbums, start + numberOfAlbumsPerTask));
executor.execute(
new Runnable() {
@Override
public void run() {
for (Album album : albumsSlice) {
formatImages(album.artworkAssetResource(), albumTargets.get(album));
int count = atomicCount.getAndIncrement() + 1;
if (progressHandler != null && count % progressModulo == 0) {
progressHandler.progress(count, String.format("#albums = %4d", count));
}
}
}
});
}
executor.shutdown();
try {
executor.awaitTermination(Long.MAX_VALUE, TimeUnit.NANOSECONDS);
} catch (InterruptedException e) {
LOGGER.warning("Interrupted: " + e.getMessage());
}
} else { // run on current thread
int count = 0;
for (Album album : albums) {
formatImages(album.artworkAssetResource(), albumTargets.get(album));
count++;
if (progressHandler != null && count % progressModulo == 0) {
progressHandler.progress(count, String.format("#albums = %4d", count));
}
}
}
if (progressHandler != null) {
progressHandler.endTask();
}
}