Local salient image storage for enhanced bookmark experiment.

components/enhanced_bookmarks/image_store.h

+// Copyright 2014 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 COMPONENTS_ENHANCED_BOOKMARKS_IMAGE_STORE_H_
+#define COMPONENTS_ENHANCED_BOOKMARKS_IMAGE_STORE_H_
+
+#include <map>
+#include <set>
+
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/threading/thread_checker.h"
+#include "ui/gfx/image/image.h"
+
+class GURL;
+
+// The ImageStore keeps an image for each URL.  This class is not thread safe,
+// and will check the thread using base::ThreadChecker, except the constructor.
+class ImageStore : public base::RefCounted<ImageStore> {
+ public:
+  ImageStore();
+
+  // Returns true if there is an image for this url.
+  virtual bool HasKey(const GURL& page_url) = 0;
+
+  // Inserts an image and its url in the store for the the given page url. The
+  // image can be null indicating that the download of the image at this URL or
+  // encoding for insertion failed previously. On non-ios platforms, |image|
+  // must have exactly one representation with a scale factor of 1.
+  virtual void Insert(const GURL& page_url,
+                      const GURL& image_url,
+                      const gfx::Image& image) = 0;
+
+  // Removes an image from the store.
+  virtual void Erase(const GURL& page_url) = 0;
+
+  // Returns the image associated with this url. Returns empty image and url if
+  // there are no image for this url. It also returns the image_url where the
+  // image was downloaded from or failed to be downloaded from.
+  virtual std::pair<gfx::Image, GURL> Get(const GURL& page_url) = 0;
+
+  // Returns the size of the image stored for this URL or empty size if no
+  // images are present.
+  virtual gfx::Size GetSize(const GURL& page_url) = 0;
+
+  // Populates |urls| with all the urls that have an image in the store.
+  virtual void GetAllPageUrls(std::set<GURL>* urls) = 0;
+
+  // Removes all images.
+  virtual void ClearAll() = 0;
+
+  // Moves an image from one url to another.
+  void ChangeImageURL(const GURL& from, const GURL& to);
+
+ protected:
+  virtual ~ImageStore();
+
+  base::ThreadChecker thread_checker_;
+
+ private:
+  friend class base::RefCounted<ImageStore>;
+
+  DISALLOW_COPY_AND_ASSIGN(ImageStore);
+};
+
+#endif  // COMPONENTS_ENHANCED_BOOKMARKS_IMAGE_STORE_H_