// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef IOS_CHROME_BROWSER_READING_LIST_MODEL_URL_DOWNLOADER_H_
#define IOS_CHROME_BROWSER_READING_LIST_MODEL_URL_DOWNLOADER_H_
#import <string>
#import "base/containers/circular_deque.h"
#import "base/files/file_path.h"
#import "base/functional/callback.h"
#import "base/memory/raw_ptr.h"
#import "base/task/cancelable_task_tracker.h"
#import "ios/chrome/browser/dom_distiller/model/distiller_viewer.h"
#import "ios/chrome/browser/reading_list/model/reading_list_distiller_page.h"
class PrefService;
class GURL;
namespace base {
class FilePath;
class SequencedTaskRunner;
} // namespace base
namespace network {
class SharedURLLoaderFactory;
class SimpleURLLoader;
} // namespace network
namespace reading_list {
class ReadingListDistillerPageFactory;
}
// This class downloads and deletes offline versions of URLs.
// If the URL points to an HTML file, `URLDownloader` uses DOM distiller to
// fetch the page and simplify it.
// If the URL points to a PDF file, the PDF is simply downloaded and saved to
// the disk.
// Only one item is downloaded or deleted at a time using a queue of tasks that
// are handled sequentially. Items (page + images) are saved to individual
// folders within an offline folder, using md5 hashing to create unique file
// names. When a deletion is requested, all previous downloads for that URL are
// cancelled as they would be deleted.
class URLDownloader : reading_list::ReadingListDistillerPageDelegate {
friend class MockURLDownloader;
public:
// And enum indicating different download outcomes.
enum SuccessState {
// The URL was correctly downloaded and an offline version is not available.
DOWNLOAD_SUCCESS,
// The URL was already available offline. No action was done.
DOWNLOAD_EXISTS,
// The URL could not be downloaded because of an error. Client may want to
// try again later.
ERROR,
// The URL could not be downloaded because of an error. Client should not
// try again.
PERMANENT_ERROR,
};
// A completion callback that takes a GURL and a bool indicating the
// outcome and returns void.
using SuccessCompletion = base::RepeatingCallback<void(const GURL&, bool)>;
// A download completion callback that takes, in order, the GURL that was
// downloaded, the GURL of the page that was downloaded after redirections, a
// SuccessState indicating the outcome of the download, the path to the
// downloaded page (relative to `OfflineRootDirectoryPath()`, and the title of
// the url, and returns void.
// The path to downloaded file and title should not be used in case of
// failure.
using DownloadCompletion = base::RepeatingCallback<void(const GURL&,
const GURL&,
SuccessState,
const base::FilePath&,
int64_t size,
const std::string&)>;
// Create a URL downloader with completion callbacks for downloads and
// deletions. The completion callbacks will be called with the original url
// and a boolean indicating success. For downloads, if distillation was
// successful, it will also include the distilled url and extracted title.
URLDownloader(
dom_distiller::DistillerFactory* distiller_factory,
reading_list::ReadingListDistillerPageFactory* distiller_page_factory,
PrefService* prefs,
base::FilePath chrome_profile_path,
scoped_refptr<network::SharedURLLoaderFactory> url_loader_factory,
const DownloadCompletion& download_completion,
const SuccessCompletion& delete_completion);
URLDownloader(const URLDownloader&) = delete;
URLDownloader& operator=(const URLDownloader&) = delete;
~URLDownloader() override;
// Asynchronously download an offline version of the URL.
void DownloadOfflineURL(const GURL& url);
// Cancels the download job an offline version of the URL.
void CancelDownloadOfflineURL(const GURL& url);
// Asynchronously remove the offline version of the URL if it exists.
void RemoveOfflineURL(const GURL& url);
// URL loader completion callback.
void OnURLLoadComplete(const GURL& original_url,
base::FilePath response_path);
// Cancels the current download task.
void CancelTask();
private:
enum TaskType { DELETE, DOWNLOAD };
using Task = std::pair<TaskType, GURL>;
// Calls callback with true if an offline path exists. `path` must be
// absolute.
void OfflinePathExists(const base::FilePath& url,
base::OnceCallback<void(bool)> callback);
// Handles the next task in the queue, if no task is currently being handled.
void HandleNextTask();
// Callback for completed (or failed) download, handles calling
// downloadCompletion on a PDF or an HTML file. Unwind result and calls
// DownloadCompletionHandler.
void DownloadPDFOrHTMLCompletionHandler(
const GURL& url,
const std::string& title,
const base::FilePath& offline_path,
std::pair<SuccessState, int64_t> result);
// Callback for completed (or failed) download, handles calling
// downloadCompletion and starting the next task.
void DownloadCompletionHandler(const GURL& url,
const std::string& title,
const base::FilePath& path,
SuccessState success);
// Callback for completed (or failed) deletion.
void PostDelete(const GURL& url,
const std::string& title,
const base::FilePath& offline_path,
SuccessState success);
// Callback for completed (or failed) deletion, handles calling
// deleteCompletion and starting the next task.
void DeleteCompletionHandler(const GURL& url, bool success);
// Downloads `url`, depending on `offlineURLExists` state.
virtual void DownloadURL(const GURL& url, bool offlineURLExists);
// ReadingListDistillerPageDelegate methods
void DistilledPageRedirectedToURL(const GURL& original_url,
const GURL& final_url) override;
void DistilledPageHasMimeType(const GURL& original_url,
const std::string& mime_type) override;
// Callback for distillation completion.
void DistillerCallback(
const GURL& pageURL,
const std::string& html,
const std::vector<dom_distiller::DistillerViewerInterface::ImageInfo>&
images,
const std::string& title,
const std::string& csp_nonce);
// PDF processing methods
// Starts fetching the PDF file. If `original_url_` triggered a redirection,
// directly save `distilled_url_`.
virtual void FetchPDFFile();
raw_ptr<reading_list::ReadingListDistillerPageFactory>
distiller_page_factory_;
raw_ptr<dom_distiller::DistillerFactory> distiller_factory_;
raw_ptr<PrefService> pref_service_;
const DownloadCompletion download_completion_;
const SuccessCompletion delete_completion_;
base::circular_deque<Task> tasks_;
bool working_;
base::FilePath base_directory_;
GURL original_url_;
GURL distilled_url_;
int64_t saved_size_;
std::string mime_type_;
// URL loader used to redownload the document and save it in the sandbox.
std::unique_ptr<network::SimpleURLLoader> url_loader_;
// URLLoaderFactory needed for the URLLoader.
scoped_refptr<network::SharedURLLoaderFactory> url_loader_factory_;
std::unique_ptr<dom_distiller::DistillerViewerInterface> distiller_;
scoped_refptr<base::SequencedTaskRunner> task_runner_;
base::CancelableTaskTracker task_tracker_;
base::WeakPtrFactory<URLDownloader> weak_factory_{this};
};
#endif // IOS_CHROME_BROWSER_READING_LIST_MODEL_URL_DOWNLOADER_H_
Codebase Browser
chromium