// Prepare the download. Returns true if the chapter is already downloaded
private boolean prepareDownload(Download download) {
// If the chapter is already queued, don't add it again
for (Download queuedDownload : queue) {
if (download.chapter.id.equals(queuedDownload.chapter.id)) return true;
}
// Add the directory to the download object for future access
download.directory = getAbsoluteChapterDirectory(download);
// If the directory doesn't exist, the chapter isn't downloaded.
if (!download.directory.exists()) {
return false;
}
// If the page list doesn't exist, the chapter isn't downloaded
List<Page> savedPages = getSavedPageList(download);
if (savedPages == null) return false;
// Add the page list to the download object for future access
download.pages = savedPages;
// If the number of files matches the number of pages, the chapter is downloaded.
// We have the index file, so we check one file more
return isChapterDownloaded(download.directory, download.pages);
}
public void stopDownloads() {
destroySubscriptions();
for (Download download : queue) {
if (download.getStatus() == Download.DOWNLOADING) {
download.setStatus(Download.ERROR);
}
}
}
public boolean startDownloads() {
if (queue.isEmpty()) return false;
boolean hasPendingDownloads = false;
if (downloadsSubscription == null) initializeSubscriptions();
for (Download download : queue) {
if (download.getStatus() != Download.DOWNLOADED) {
if (download.getStatus() != Download.QUEUE) download.setStatus(Download.QUEUE);
if (!hasPendingDownloads) hasPendingDownloads = true;
downloadsQueueSubject.onNext(download);
}
}
return hasPendingDownloads;
}
private void checkDownloadIsSuccessful(final Download download) {
int actualProgress = 0;
int status = Download.DOWNLOADED;
// If any page has an error, the download result will be error
for (Page page : download.pages) {
actualProgress += page.getProgress();
if (page.getStatus() != Page.READY) status = Download.ERROR;
}
// Ensure that the chapter folder has all the images
if (!isChapterDownloaded(download.directory, download.pages)) {
status = Download.ERROR;
}
download.totalProgress = actualProgress;
download.setStatus(status);
// Delete successful downloads from queue after notifying
if (status == Download.DOWNLOADED) {
queue.remove(download);
}
}
// Download the entire chapter
private Observable<Download> downloadChapter(Download download) {
try {
DiskUtils.createDirectory(download.directory);
} catch (IOException e) {
return Observable.error(e);
}
Observable<List<Page>> pageListObservable =
download.pages == null
?
// Pull page list from network and add them to download object
download
.source
.pullPageListFromNetwork(download.chapter.url)
.doOnNext(pages -> download.pages = pages)
.doOnNext(pages -> savePageList(download))
:
// Or if the page list already exists, start from the file
Observable.just(download.pages);
return pageListObservable
.subscribeOn(Schedulers.io())
.doOnNext(
pages -> {
download.downloadedImages = 0;
download.setStatus(Download.DOWNLOADING);
})
// Get all the URLs to the source images, fetch pages if necessary
.flatMap(download.source::getAllImageUrlsFromPageList)
// Start downloading images, consider we can have downloaded images already
.concatMap(page -> getOrDownloadImage(page, download))
// Do after download completes
.doOnCompleted(() -> onDownloadCompleted(download))
.toList()
.map(pages -> download)
// If the page list threw, it will resume here
.onErrorResumeNext(
error -> {
download.setStatus(Download.ERROR);
return Observable.just(download);
});
}
public boolean areAllDownloadsFinished() {
for (Download download : queue) {
if (download.getStatus() <= Download.DOWNLOADING) return false;
}
return true;
}