1 // Copyright (c) 2012 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. 4 5 #ifndef CHROME_BROWSER_HISTORY_TOP_SITES_CACHE_H_ 6 #define CHROME_BROWSER_HISTORY_TOP_SITES_CACHE_H_ 7 8 #include <map> 9 #include <utility> 10 11 #include "base/memory/ref_counted.h" 12 #include "chrome/browser/history/history_types.h" 13 14 namespace history { 15 16 // TopSitesCache caches the top sites and thumbnails for TopSites. 17 class TopSitesCache { 18 public: 19 TopSitesCache(); 20 ~TopSitesCache(); 21 22 // The top sites. 23 void SetTopSites(const MostVisitedURLList& top_sites); 24 const MostVisitedURLList& top_sites() const { return top_sites_; } 25 26 // The thumbnails. 27 void SetThumbnails(const URLToImagesMap& images); 28 const URLToImagesMap& images() const { return images_; } 29 30 // Returns the thumbnail as an Image for the specified url. This adds an entry 31 // for |url| if one has not yet been added. 32 Images* GetImage(const GURL& url); 33 34 // Fetches the thumbnail for the specified url. Returns true if there is a 35 // thumbnail for the specified url. It is possible for a URL to be in TopSites 36 // but not have an thumbnail. 37 bool GetPageThumbnail(const GURL& url, 38 scoped_refptr<base::RefCountedMemory>* bytes); 39 40 // Fetches the thumbnail score for the specified url. Returns true if 41 // there is a thumbnail score for the specified url. 42 bool GetPageThumbnailScore(const GURL& url, ThumbnailScore* score); 43 44 // Returns the canonical URL for |url|. 45 const GURL& GetCanonicalURL(const GURL& url); 46 47 // Returns true if |url| is known. 48 bool IsKnownURL(const GURL& url); 49 50 // Returns the index into |top_sites_| for |url|. 51 size_t GetURLIndex(const GURL& url); 52 53 private: 54 // The entries in CanonicalURLs, see CanonicalURLs for details. The second 55 // argument gives the index of the URL into MostVisitedURLs redirects. 56 typedef std::pair<MostVisitedURL*, size_t> CanonicalURLEntry; 57 58 // Comparator used for CanonicalURLs. 59 class CanonicalURLComparator { 60 public: 61 bool operator()(const CanonicalURLEntry& e1, 62 const CanonicalURLEntry& e2) const { 63 return e1.first->redirects[e1.second] < e2.first->redirects[e2.second]; 64 } 65 }; 66 67 // This is used to map from redirect url to the MostVisitedURL the redirect is 68 // from. Ideally this would be map<GURL, size_t> (second param indexing into 69 // top_sites_), but this results in duplicating all redirect urls. As some 70 // sites have a lot of redirects, we instead use the MostVisitedURL* and the 71 // index of the redirect as the key, and the index into top_sites_ as the 72 // value. This way we aren't duplicating GURLs. CanonicalURLComparator 73 // enforces the ordering as if we were using GURLs. 74 typedef std::map<CanonicalURLEntry, size_t, 75 CanonicalURLComparator> CanonicalURLs; 76 77 // Generates the set of canonical urls from |top_sites_|. 78 void GenerateCanonicalURLs(); 79 80 // Stores a set of redirects. This is used by GenerateCanonicalURLs. 81 void StoreRedirectChain(const RedirectList& redirects, size_t destination); 82 83 // Returns the iterator into canconical_urls_ for the specified url. 84 CanonicalURLs::iterator GetCanonicalURLsIterator(const GURL& url); 85 86 // The top sites. 87 MostVisitedURLList top_sites_; 88 89 // The images. These map from canonical url to image. 90 URLToImagesMap images_; 91 92 // Generated from the redirects to and from the most visited pages. See 93 // description above typedef for details. 94 CanonicalURLs canonical_urls_; 95 96 DISALLOW_COPY_AND_ASSIGN(TopSitesCache); 97 }; 98 99 } // namespace history 100 101 #endif // CHROME_BROWSER_HISTORY_TOP_SITES_CACHE_H_ 102
