1 // Copyright 2013 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef CHROME_BROWSER_DOWNLOAD_DOWNLOAD_TARGET_DETERMINER_H_
6 #define CHROME_BROWSER_DOWNLOAD_DOWNLOAD_TARGET_DETERMINER_H_
8 #include "base/files/file_path.h"
9 #include "base/memory/ref_counted.h"
10 #include "base/memory/scoped_ptr.h"
11 #include "base/memory/weak_ptr.h"
12 #include "chrome/browser/common/cancelable_request.h"
13 #include "chrome/browser/download/download_path_reservation_tracker.h"
14 #include "chrome/browser/download/download_target_determiner_delegate.h"
15 #include "content/public/browser/download_danger_type.h"
16 #include "content/public/browser/download_item.h"
17 #include "content/public/browser/download_manager_delegate.h"
19 class ChromeDownloadManagerDelegate;
24 enum DownloadDangerType;
27 // Determines the target of the download.
30 // Virtual Path: A path representing the target of the download that may or
31 // may not be a physical file path. E.g. if the target of the download is in
32 // cloud storage, then the virtual path may be relative to a logical mount
35 // Local Path: A local file system path where the downloads system should
38 // Intermediate Path: Where the data should be written to during the course of
39 // the download. Once the download completes, the file could be renamed to
42 // DownloadTargetDeterminer is a self owned object that performs the work of
43 // determining the download target. It observes the DownloadItem and aborts the
44 // process if the download is removed. DownloadTargetDeterminerDelegate is
45 // responsible for providing external dependencies and prompting the user if
48 // The only public entrypoint is the static Start() method which creates an
49 // instance of DownloadTargetDeterminer.
50 class DownloadTargetDeterminer
51 : public content::DownloadItem::Observer {
53 // Start the process of determing the target of |download|.
55 // |initial_virtual_path| if non-empty, defines the initial virtual path for
56 // the target determination process. If one isn't specified, one will be
57 // generated based on the response data specified in |download| and the
58 // users' downloads directory.
59 // Note: |initial_virtual_path| is only used if download has prompted the
60 // user before and doesn't have a forced path.
61 // |download_prefs| is required and must outlive |download|. It is used for
62 // determining the user's preferences regarding the default downloads
63 // directory, prompting and auto-open behavior.
64 // |delegate| is required and must live until |callback| is invoked.
65 // |callback| will be scheduled asynchronously on the UI thread after download
66 // determination is complete or after |download| is destroyed.
68 // Start() should be called on the UI thread.
69 static void Start(content::DownloadItem* download,
70 const base::FilePath& initial_virtual_path,
71 DownloadPrefs* download_prefs,
72 DownloadTargetDeterminerDelegate* delegate,
73 const content::DownloadTargetCallback& callback);
75 // Returns a .crdownload intermediate path for the |suggested_path|.
76 static base::FilePath GetCrDownloadPath(const base::FilePath& suggested_path);
79 // The main workflow is controlled via a set of state transitions. Each state
80 // has an associated handler. The handler for STATE_FOO is DoFoo. Each handler
81 // performs work, determines the next state to transition to and returns a
82 // Result indicating how the workflow should proceed. The loop ends when a
83 // handler returns COMPLETE.
85 STATE_GENERATE_TARGET_PATH,
86 STATE_NOTIFY_EXTENSIONS,
87 STATE_RESERVE_VIRTUAL_PATH,
88 STATE_PROMPT_USER_FOR_DOWNLOAD_PATH,
89 STATE_DETERMINE_LOCAL_PATH,
90 STATE_CHECK_DOWNLOAD_URL,
91 STATE_CHECK_VISITED_REFERRER_BEFORE,
92 STATE_DETERMINE_INTERMEDIATE_PATH,
96 // Result code returned by each step of the workflow below. Controls execution
99 // Continue processing. next_state_ is required to not be STATE_NONE.
102 // The DoLoop() that invoked the handler should exit. This value is
103 // typically returned when the handler has invoked an asynchronous operation
104 // and is expecting a callback. If a handler returns this value, it has
105 // taken responsibility for ensuring that DoLoop() is invoked. It is
106 // possible that the handler has invoked another DoLoop() already.
109 // Target determination is complete.
113 // Used with IsDangerousFile to indicate whether the user has visited the
114 // referrer URL for the download prior to today.
115 enum PriorVisitsToReferrer {
116 NO_VISITS_TO_REFERRER,
120 // Construct a DownloadTargetDeterminer object. Constraints on the arguments
121 // are as per Start() above.
122 DownloadTargetDeterminer(
123 content::DownloadItem* download,
124 const base::FilePath& initial_virtual_path,
125 DownloadPrefs* download_prefs,
126 DownloadTargetDeterminerDelegate* delegate,
127 const content::DownloadTargetCallback& callback);
129 virtual ~DownloadTargetDeterminer();
131 // Invoke each successive handler until a handler returns QUIT_DOLOOP or
132 // COMPLETE. Note that as a result, this object might be deleted. So |this|
133 // should not be accessed after calling DoLoop().
136 // === Main workflow ===
138 // Generates an initial target path. This target is based only on the state of
139 // the download item.
141 // - STATE_NONE : If the download is not in progress, returns COMPLETE.
142 // - STATE_NOTIFY_EXTENSIONS : All other downloads.
143 Result DoGenerateTargetPath();
145 // Notifies downloads extensions. If any extension wishes to override the
146 // download filename, it will respond to the OnDeterminingFilename()
149 // - STATE_RESERVE_VIRTUAL_PATH.
150 Result DoNotifyExtensions();
152 // Callback invoked after extensions are notified. Updates |virtual_path_| and
153 // |conflict_action_|.
154 void NotifyExtensionsDone(
155 const base::FilePath& new_path,
156 DownloadPathReservationTracker::FilenameConflictAction conflict_action);
158 // Invokes ReserveVirtualPath() on the delegate to acquire a reservation for
159 // the path. See DownloadPathReservationTracker.
161 // - STATE_PROMPT_USER_FOR_DOWNLOAD_PATH.
162 Result DoReserveVirtualPath();
164 // Callback invoked after the delegate aquires a path reservation.
165 void ReserveVirtualPathDone(const base::FilePath& path, bool verified);
167 // Presents a file picker to the user if necessary.
169 // - STATE_DETERMINE_LOCAL_PATH.
170 Result DoPromptUserForDownloadPath();
172 // Callback invoked after the file picker completes. Cancels the download if
173 // the user cancels the file picker.
174 void PromptUserForDownloadPathDone(const base::FilePath& virtual_path);
176 // Up until this point, the path that was used is considered to be a virtual
177 // path. This step determines the local file system path corresponding to this
178 // virtual path. The translation is done by invoking the DetermineLocalPath()
179 // method on the delegate.
181 // - STATE_CHECK_DOWNLOAD_URL.
182 Result DoDetermineLocalPath();
184 // Callback invoked when the delegate has determined local path.
185 void DetermineLocalPathDone(const base::FilePath& local_path);
187 // Checks whether the downloaded URL is malicious. Invokes the
188 // DownloadProtectionService via the delegate.
190 // - STATE_CHECK_VISITED_REFERRER_BEFORE.
191 Result DoCheckDownloadUrl();
193 // Callback invoked after the delegate has checked the download URL. Sets the
194 // danger type of the download to |danger_type|.
195 void CheckDownloadUrlDone(content::DownloadDangerType danger_type);
197 // Checks if the user has visited the referrer URL of the download prior to
198 // today. The actual check is only performed if it would be needed to
199 // determine the danger type of the download.
201 // - STATE_DETERMINE_INTERMEDIATE_PATH.
202 Result DoCheckVisitedReferrerBefore();
204 // Callback invoked after completion of history check for prior visits to
206 void CheckVisitedReferrerBeforeDone(bool visited_referrer_before);
208 // Determines the intermediate path. Once this step completes, downloads
209 // target determination is complete. The determination assumes that the
210 // intermediate file will never be overwritten (always uniquified if needed).
212 // - STATE_NONE: Returns COMPLETE.
213 Result DoDetermineIntermediatePath();
215 // === End of main workflow ===
219 void ScheduleCallbackAndDeleteSelf();
221 void CancelOnFailureAndDeleteSelf();
223 Profile* GetProfile();
225 // Determine whether to prompt the user for the download location. For regular
226 // downloads, this determination is based on the target disposition, auto-open
227 // behavior, among other factors. For an interrupted download, this
228 // determination will be based on the interrupt reason. It is assumed that
229 // download interruptions always occur after the first round of download
230 // target determination is complete.
231 bool ShouldPromptForDownload(const base::FilePath& filename) const;
233 // Returns true if the user has been prompted for this download at least once
234 // prior to this target determination operation. This method is only expected
235 // to return true for a resuming interrupted download that has prompted the
236 // user before interruption. The return value does not depend on whether the
237 // user will be or has been prompted during the current target determination
239 bool HasPromptedForPath() const;
241 // Returns true if this download should show the "dangerous file" warning.
242 // Various factors are considered, such as the type of the file, whether a
243 // user action initiated the download, and whether the user has explicitly
244 // marked the file type as "auto open". Protected virtual for testing.
245 bool IsDangerousFile(PriorVisitsToReferrer visits);
247 // content::DownloadItem::Observer
248 virtual void OnDownloadDestroyed(content::DownloadItem* download) OVERRIDE;
253 bool should_notify_extensions_;
254 bool create_target_directory_;
255 DownloadPathReservationTracker::FilenameConflictAction conflict_action_;
256 content::DownloadDangerType danger_type_;
257 base::FilePath virtual_path_;
258 base::FilePath local_path_;
259 base::FilePath intermediate_path_;
261 content::DownloadItem* download_;
262 const bool is_resumption_;
263 DownloadPrefs* download_prefs_;
264 DownloadTargetDeterminerDelegate* delegate_;
265 content::DownloadTargetCallback completion_callback_;
266 CancelableRequestConsumer history_consumer_;
268 base::WeakPtrFactory<DownloadTargetDeterminer> weak_ptr_factory_;
270 DISALLOW_COPY_AND_ASSIGN(DownloadTargetDeterminer);
273 #endif // CHROME_BROWSER_DOWNLOAD_DOWNLOAD_TARGET_DETERMINER_H_