// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CHROME_BROWSER_HISTORY_TOP_SITES_IMPL_H_
#define CHROME_BROWSER_HISTORY_TOP_SITES_IMPL_H_
#include <list>
#include <set>
#include <string>
#include <utility>
#include <vector>
#include "base/basictypes.h"
#include "base/callback.h"
#include "base/gtest_prod_util.h"
#include "base/memory/ref_counted.h"
#include "base/synchronization/lock.h"
#include "base/task/cancelable_task_tracker.h"
#include "base/time/time.h"
#include "base/timer/timer.h"
#include "chrome/browser/common/cancelable_request.h"
#include "chrome/browser/history/history_service.h"
#include "chrome/browser/history/history_types.h"
#include "chrome/browser/history/page_usage_data.h"
#include "chrome/browser/history/top_sites.h"
#include "chrome/browser/history/top_sites_backend.h"
#include "chrome/common/thumbnail_score.h"
#include "third_party/skia/include/core/SkColor.h"
#include "ui/gfx/image/image.h"
#include "url/gurl.h"
class Profile;
namespace base {
class FilePath;
class RefCountedBytes;
class RefCountedMemory;
}
namespace history {
class TopSitesCache;
class TopSitesImplTest;
// This class allows requests for most visited urls and thumbnails on any
// thread. All other methods must be invoked on the UI thread. All mutations
// to internal state happen on the UI thread and are scheduled to update the
// db using TopSitesBackend.
class TopSitesImpl : public TopSites {
public:
explicit TopSitesImpl(Profile* profile);
// Initializes TopSitesImpl.
void Init(const base::FilePath& db_name);
virtual bool SetPageThumbnail(const GURL& url,
const gfx::Image& thumbnail,
const ThumbnailScore& score) OVERRIDE;
virtual bool SetPageThumbnailToJPEGBytes(
const GURL& url,
const base::RefCountedMemory* memory,
const ThumbnailScore& score) OVERRIDE;
virtual void GetMostVisitedURLs(
const GetMostVisitedURLsCallback& callback,
bool include_forced_urls) OVERRIDE;
virtual bool GetPageThumbnail(
const GURL& url,
bool prefix_match,
scoped_refptr<base::RefCountedMemory>* bytes) OVERRIDE;
virtual bool GetPageThumbnailScore(const GURL& url,
ThumbnailScore* score) OVERRIDE;
virtual bool GetTemporaryPageThumbnailScore(const GURL& url,
ThumbnailScore* score) OVERRIDE;
virtual void SyncWithHistory() OVERRIDE;
virtual bool HasBlacklistedItems() const OVERRIDE;
virtual void AddBlacklistedURL(const GURL& url) OVERRIDE;
virtual void RemoveBlacklistedURL(const GURL& url) OVERRIDE;
virtual bool IsBlacklisted(const GURL& url) OVERRIDE;
virtual void ClearBlacklistedURLs() OVERRIDE;
virtual void Shutdown() OVERRIDE;
virtual CancelableRequestProvider::Handle StartQueryForMostVisited() OVERRIDE;
virtual bool IsKnownURL(const GURL& url) OVERRIDE;
virtual const std::string& GetCanonicalURLString(
const GURL& url) const OVERRIDE;
virtual bool IsNonForcedFull() OVERRIDE;
virtual bool IsForcedFull() OVERRIDE;
virtual MostVisitedURLList GetPrepopulatePages() OVERRIDE;
virtual bool loaded() const OVERRIDE;
virtual bool AddForcedURL(const GURL& url, const base::Time& time) OVERRIDE;
protected:
virtual ~TopSitesImpl();
private:
friend class TopSitesImplTest;
FRIEND_TEST_ALL_PREFIXES(TopSitesImplTest, DiffMostVisited);
FRIEND_TEST_ALL_PREFIXES(TopSitesImplTest, DiffMostVisitedWithForced);
typedef base::Callback<void(const MostVisitedURLList&,
const MostVisitedURLList&)> PendingCallback;
typedef std::pair<GURL, Images> TempImage;
typedef std::list<TempImage> TempImages;
typedef std::vector<PendingCallback> PendingCallbacks;
// Generates the diff of things that happened between "old" and "new."
//
// This treats forced URLs separately than non-forced URLs.
//
// The URLs that are in "new" but not "old" will be have their index into
// "new" put in |added_urls|. The non-forced URLs that are in "old" but not
// "new" will have their index into "old" put into |deleted_urls|.
//
// URLs appearing in both old and new lists but having different indices will
// have their index into "new" be put into |moved_urls|.
static void DiffMostVisited(const MostVisitedURLList& old_list,
const MostVisitedURLList& new_list,
TopSitesDelta* delta);
// Sets the thumbnail without writing to the database. Useful when
// reading last known top sites from the DB.
// Returns true if the thumbnail was set, false if the existing one is better.
bool SetPageThumbnailNoDB(const GURL& url,
const base::RefCountedMemory* thumbnail_data,
const ThumbnailScore& score);
// A version of SetPageThumbnail that takes RefCountedBytes as
// returned by HistoryService.
bool SetPageThumbnailEncoded(const GURL& url,
const base::RefCountedMemory* thumbnail,
const ThumbnailScore& score);
// Encodes the bitmap to bytes for storage to the db. Returns true if the
// bitmap was successfully encoded.
static bool EncodeBitmap(const gfx::Image& bitmap,
scoped_refptr<base::RefCountedBytes>* bytes);
// Removes the cached thumbnail for url. Does nothing if |url| if not cached
// in |temp_images_|.
void RemoveTemporaryThumbnailByURL(const GURL& url);
// Add a thumbnail for an unknown url. See temp_thumbnails_map_.
void AddTemporaryThumbnail(const GURL& url,
const base::RefCountedMemory* thumbnail,
const ThumbnailScore& score);
// Called by our timer. Starts the query for the most visited sites.
void TimerFired();
// Finds the given URL in the redirect chain for the given TopSite, and
// returns the distance from the destination in hops that the given URL is.
// The URL is assumed to be in the list. The destination is 0.
static int GetRedirectDistanceForURL(const MostVisitedURL& most_visited,
const GURL& url);
// Add prepopulated pages: 'welcome to Chrome' and themes gallery to |urls|.
// Returns true if any pages were added.
bool AddPrepopulatedPages(MostVisitedURLList* urls,
size_t num_forced_urls);
// Add all the forced URLs from |cache_| into |new_list|, making sure not to
// add any URL that's already in |new_list|'s non-forced URLs. The forced URLs
// in |cache_| and |new_list| are assumed to appear at the front of the list
// and be sorted in increasing |last_forced_time|. This will still be true
// after the call. If the list of forced URLs overflows the older ones are
// dropped. Returns the number of forced URLs after the merge.
size_t MergeCachedForcedURLs(MostVisitedURLList* new_list);
// Takes |urls|, produces it's copy in |out| after removing blacklisted URLs.
// Also ensures we respect the maximum number of forced URLs and non-forced
// URLs.
void ApplyBlacklist(const MostVisitedURLList& urls, MostVisitedURLList* out);
// Returns an MD5 hash of the URL. Hashing is required for blacklisted URLs.
std::string GetURLHash(const GURL& url);
// Returns the delay until the next update of history is needed.
// Uses num_urls_changed
base::TimeDelta GetUpdateDelay();
// Implementation of content::NotificationObserver.
virtual void Observe(int type,
const content::NotificationSource& source,
const content::NotificationDetails& details) OVERRIDE;
// Updates URLs in |cache_| and the db (in the background).
// The non-forced URLs in |new_top_sites| replace those in |cache_|.
// The forced URLs of |new_top_sites| are merged with those in |cache_|,
// if the list of forced URLs overflows, the oldest ones are dropped.
// All mutations to cache_ *must* go through this. Should
// be called from the UI thread.
void SetTopSites(const MostVisitedURLList& new_top_sites);
// Returns the number of most visited results to request from history. This
// changes depending upon how many urls have been blacklisted. Should be
// called from the UI thread.
int num_results_to_request_from_history() const;
// Invoked when transitioning to LOADED. Notifies any queued up callbacks.
// Should be called from the UI thread.
void MoveStateToLoaded();
void ResetThreadSafeCache();
void ResetThreadSafeImageCache();
void NotifyTopSitesChanged();
// Stops and starts timer with a delay of |delta|.
void RestartQueryForTopSitesTimer(base::TimeDelta delta);
// Callback from TopSites with the top sites/thumbnails. Should be called
// from the UI thread.
void OnGotMostVisitedThumbnails(
const scoped_refptr<MostVisitedThumbnails>& thumbnails);
// Called when history service returns a list of top URLs.
void OnTopSitesAvailableFromHistory(CancelableRequestProvider::Handle handle,
MostVisitedURLList data);
scoped_refptr<TopSitesBackend> backend_;
// The top sites data.
scoped_ptr<TopSitesCache> cache_;
// Copy of the top sites data that may be accessed on any thread (assuming
// you hold |lock_|). The data in |thread_safe_cache_| has blacklisted and
// pinned urls applied (|cache_| does not).
scoped_ptr<TopSitesCache> thread_safe_cache_;
Profile* profile_;
// Lock used to access |thread_safe_cache_|.
mutable base::Lock lock_;
// Need a separate consumer for each CancelableRequestProvider we interact
// with (HistoryService and TopSitesBackend).
CancelableRequestConsumer history_consumer_;
base::CancelableTaskTracker cancelable_task_tracker_;
// Timer that asks history for the top sites. This is used to make sure our
// data stays in sync with history.
base::OneShotTimer<TopSitesImpl> timer_;
// The time we started |timer_| at. Only valid if |timer_| is running.
base::TimeTicks timer_start_time_;
content::NotificationRegistrar registrar_;
// The number of URLs changed on the last update.
size_t last_num_urls_changed_;
// The pending requests for the top sites list. Can only be non-empty at
// startup. After we read the top sites from the DB, we'll always have a
// cached list and be able to run callbacks immediately.
PendingCallbacks pending_callbacks_;
// Stores thumbnails for unknown pages. When SetPageThumbnail is
// called, if we don't know about that URL yet and we don't have
// enough Top Sites (new profile), we store it until the next
// SetNonForcedTopSites call.
TempImages temp_images_;
// URL List of prepopulated page.
std::vector<GURL> prepopulated_page_urls_;
// Are we loaded?
bool loaded_;
DISALLOW_COPY_AND_ASSIGN(TopSitesImpl);
};
} // namespace history
#endif // CHROME_BROWSER_HISTORY_TOP_SITES_IMPL_H_