components/favicon/core/favicon_database.h - chromium/src - Git at Google

 // Copyright 2012 The Chromium Authors
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #ifndef COMPONENTS_FAVICON_CORE_FAVICON_DATABASE_H_
 #define COMPONENTS_FAVICON_CORE_FAVICON_DATABASE_H_

 #include <optional>
 #include <vector>

 #include "base/feature_list.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/ref_counted.h"
 #include "components/favicon/core/favicon_types.h"
 #include "sql/database.h"
 #include "sql/init_status.h"
 #include "sql/meta_table.h"
 #include "sql/statement.h"

 namespace base {
 class FilePath;
 class RefCountedMemory;
 class Time;
 }  // namespace base

 namespace url {
 class Origin;
 }  // namespace url

 namespace favicon {

 // The minimum number of days after which last_requested field gets updated.
 // All earlier updates are ignored.
 static const int kFaviconUpdateLastRequestedAfterDays = 10;

 // This database interface is owned by the history backend and runs on the
 // history thread.
 class FaviconDatabase {
  public:
   FaviconDatabase();
   ~FaviconDatabase();

   // Must be called after creation but before any other methods are called.
   // When not INIT_OK, no other functions should be called.
   sql::InitStatus Init(const base::FilePath& db_name);

   // Computes and records various metrics for the database. Should only be
   // called once and only upon successful Init.
   void ComputeDatabaseMetrics();

   // Transactions on the database.
   void BeginTransaction();
   void CommitTransaction();
   int transaction_nesting() const { return db_.transaction_nesting(); }
   void RollbackTransaction();

   // Vacuums the database. This will cause sqlite to defragment and collect
   // unused space in the file. It can be VERY SLOW.
   void Vacuum();

   // Release all non-essential memory associated with this database connection.
   void TrimMemory();

   // Get all on-demand favicon bitmaps that have been last requested prior to
   // `threshold`.
   std::map<favicon_base::FaviconID, IconMappingsForExpiry>
   GetOldOnDemandFavicons(base::Time threshold);

   // Favicon Bitmaps -----------------------------------------------------------

   // Returns true if there are favicon bitmaps for `icon_id`. If
   // `bitmap_id_sizes` is non NULL, sets it to a list of the favicon bitmap ids
   // and their associated pixel sizes for the favicon with `icon_id`.
   // The list contains results for the bitmaps which are cached in the
   // favicon_bitmaps table. The pixel sizes are a subset of the sizes in the
   // 'sizes' field of the favicons table for `icon_id`.
   bool GetFaviconBitmapIDSizes(
       favicon_base::FaviconID icon_id,
       std::vector<FaviconBitmapIDSize>* bitmap_id_sizes);

   // Returns true if there are any matched bitmaps for the given `icon_id`. All
   // matched results are returned if `favicon_bitmaps` is not NULL.
   bool GetFaviconBitmaps(favicon_base::FaviconID icon_id,
                          std::vector<FaviconBitmap>* favicon_bitmaps);

   // Gets the last updated time, bitmap data, and pixel size of the favicon
   // bitmap at `bitmap_id`. Returns true if successful.
   bool GetFaviconBitmap(FaviconBitmapID bitmap_id,
                         base::Time* last_updated,
                         base::Time* last_requested,
                         scoped_refptr<base::RefCountedMemory>* png_icon_data,
                         gfx::Size* pixel_size);

   // Adds a bitmap component of `type` at `pixel_size` for the favicon with
   // `icon_id`. Only favicons representing a .ico file should have multiple
   // favicon bitmaps per favicon.
   // `icon_data` is the png encoded data.
   // The `type` indicates how the lifetime of this icon should be managed.
   // The `time` is used for lifetime management of the bitmap (should be Now()).
   // `pixel_size` is the pixel dimensions of `icon_data`.
   // Returns the id of the added bitmap or 0 if unsuccessful.
   FaviconBitmapID AddFaviconBitmap(
       favicon_base::FaviconID icon_id,
       scoped_refptr<base::RefCountedMemory> icon_data,
       FaviconBitmapType type,
       base::Time time,
       const gfx::Size& pixel_size);

   // Sets the bitmap data and the last updated time for the favicon bitmap at
   // `bitmap_id`. Should not be called for bitmaps of type ON_DEMAND as they
   // should never get updated (the call silently changes the type to ON_VISIT).
   // Returns true if successful.
   bool SetFaviconBitmap(FaviconBitmapID bitmap_id,
                         scoped_refptr<base::RefCountedMemory> bitmap_data,
                         base::Time time);

   // Sets the last_updated time for the favicon bitmap at `bitmap_id`. Should
   // not be called for bitmaps of type ON_DEMAND as last_updated time is only
   // tracked for ON_VISIT bitmaps (the call silently changes the type to
   // ON_VISIT). Returns true if successful.
   bool SetFaviconBitmapLastUpdateTime(FaviconBitmapID bitmap_id,
                                       base::Time time);

   // Deletes the favicon bitmap with `bitmap_id`.
   // Returns true if successful.
   bool DeleteFaviconBitmap(FaviconBitmapID bitmap_id);

   // Favicons ------------------------------------------------------------------

   // Sets the the favicon as out of date. This will set `last_updated` for all
   // of the bitmaps for `icon_id` to be out of date.
   bool SetFaviconOutOfDate(favicon_base::FaviconID icon_id);

   // Mark all favicons as out of date that have been modified at or after
   // `begin` and before `end`. This will set `last_updated` for all matching
   // bitmaps to be out of date.
   bool SetFaviconsOutOfDateBetween(base::Time begin, base::Time end);

   // Retrieves the newest `last_updated` time across all bitmaps for `icon_id`.
   // Returns true if successful and if there is at least one bitmap.
   bool GetFaviconLastUpdatedTime(favicon_base::FaviconID icon_id,
                                  base::Time* last_updated);

   // Mark all bitmaps of type ON_DEMAND at `icon_url` as requested at `time`.
   // This postpones their automatic eviction from the database. Not all calls
   // end up in a write into the DB:
   // - it is no-op if the bitmaps are not of type ON_DEMAND;
   // - the updates of the "last requested time" have limited frequency for each
   //   particular bitmap (e.g. once per week). This limits the overhead of
   //   cache management for on-demand favicons.
   // Returns true if successful.
   bool TouchOnDemandFavicon(const GURL& icon_url, base::Time time);

   // Returns the id of the entry in the favicon database with the specified
   // `icon_url` and `icon_type` that has an existing mapping to `page_origin`
   // (and 0 if no entry exists). See crbug.com/1300214 for more context.
   favicon_base::FaviconID GetFaviconIDForFaviconURL(
       const GURL& icon_url,
       favicon_base::IconType icon_type,
       const url::Origin& page_origin);

   // Returns the id of the entry in the favicon database with the specified
   // `icon_url` and `icon_type` (and 0 if no entry exists). This function does
   // not respect cross-origin partitioning and returns an entry from the cache
   // without verifying it was stored for the origin requesting it. This can leak
   // navigation history, see crbug.com/1300214 for more context.
   favicon_base::FaviconID GetFaviconIDForFaviconURL(
       const GURL& icon_url,
       favicon_base::IconType icon_type);

   // Gets the icon_url, icon_type and sizes for the specified `icon_id`.
   bool GetFaviconHeader(favicon_base::FaviconID icon_id,
                         GURL* icon_url,
                         favicon_base::IconType* icon_type);

   // Adds favicon with `icon_url`, `icon_type` and `favicon_sizes` to the
   // favicon db, returning its id.
   favicon_base::FaviconID AddFavicon(const GURL& icon_url,
                                      favicon_base::IconType icon_type);

   // Adds a favicon with a single bitmap. This call is equivalent to calling
   // AddFavicon and AddFaviconBitmap of type `type`.
   favicon_base::FaviconID AddFavicon(
       const GURL& icon_url,
       favicon_base::IconType icon_type,
       scoped_refptr<base::RefCountedMemory> icon_data,
       FaviconBitmapType type,
       base::Time time,
       const gfx::Size& pixel_size);

   // Delete the favicon with the provided id. Returns false on failure
   bool DeleteFavicon(favicon_base::FaviconID id);

   // Icon Mapping --------------------------------------------------------------
   //
   // Returns true if there is a matched icon mapping for the given page and
   // icon type.
   // The matched icon mapping is returned in the icon_mapping parameter if it is
   // not NULL.

   // Returns true if there are icon mappings for the given page and icon types.
   // The matched icon mappings are returned in the `mapping_data` parameter if
   // it is not NULL.
   bool GetIconMappingsForPageURL(
       const GURL& page_url,
       const favicon_base::IconTypeSet& required_icon_types,
       std::vector<IconMapping>* mapping_data);

   // Returns true if there is any matched icon mapping for the given page.
   // All matched icon mappings are returned in descent order of IconType if
   // mapping_data is not NULL.
   bool GetIconMappingsForPageURL(const GURL& page_url,
                                  std::vector<IconMapping>* mapping_data);

   // Given `url`, returns the `page_url` page mapped to an icon with
   // `required_icon_types`, where `page_url` has host = url.host(). The search
   // prioritizes `PageUrlType::kRegular` over `PageUrlType::kRedirect` on the
   // assumption that `url` is not a cross-host redirect. This enables icons
   // to be retrieved when a full URL is not available. For example,
   // `url` = http://www.google.com would match
   // `page_url` = https://www.google.com/search.
   // The returned optional will be empty if no such `page_url` exists.
   std::optional<GURL> FindBestPageURLForHost(
       const GURL& url,
       const favicon_base::IconTypeSet& required_icon_types);

   // Adds a mapping between the given `page_url` and `icon_id`. A
   // `page_url_type` must also be provided. It is not possible to store multiple
   // entries for a (`page_url`, `icon_id`) pair with different `page_url_type`s.
   // Returns the new mapping id if the adding succeeds, otherwise 0 is returned.
   IconMappingID AddIconMapping(const GURL& page_url,
                                favicon_base::FaviconID icon_id,
                                PageUrlType page_url_type);

   // Deletes the icon mapping entries for the given page url.
   // Returns true if the deletion succeeded.
   bool DeleteIconMappings(const GURL& page_url);

   // Deletes the icon mapping entries for the given favicon ID.
   // Returns true if the deletion succeeded.
   bool DeleteIconMappingsForFaviconId(favicon_base::FaviconID id);

   // Deletes the icon mapping with `mapping_id`.
   // Returns true if the deletion succeeded.
   bool DeleteIconMapping(IconMappingID mapping_id);

   // Checks whether a favicon is used by any URLs in the database.
   bool HasMappingFor(favicon_base::FaviconID id);

   // Returns the ids of favicons which were last updated before `time`. This
   // returns at most `max_count` ids.
   std::vector<favicon_base::FaviconID> GetFaviconsLastUpdatedBefore(
       base::Time time,
       int max_count);

   // The class to enumerate icon mappings. Use InitIconMappingEnumerator to
   // initialize.
   class IconMappingEnumerator {
    public:
     IconMappingEnumerator();

     IconMappingEnumerator(const IconMappingEnumerator&) = delete;
     IconMappingEnumerator& operator=(const IconMappingEnumerator&) = delete;

     ~IconMappingEnumerator();

     // Get the next icon mapping, return false if no more are available.
     bool GetNextIconMapping(IconMapping* icon_mapping);

    private:
     friend class FaviconDatabase;

     // Used to query database and return the data for filling IconMapping in
     // each call of GetNextIconMapping().
     sql::Statement statement_;
   };

   // Return all icon mappings of the given `icon_type`.
   bool InitIconMappingEnumerator(favicon_base::IconType type,
                                  IconMappingEnumerator* enumerator);

   // Remove all data except that associated with the passed page urls.
   // Returns false in case of failure.  A nested transaction is used,
   // so failure causes any outer transaction to be rolled back.
   bool RetainDataForPageUrls(const std::vector<GURL>& urls_to_keep);

  private:
   FRIEND_TEST_ALL_PREFIXES(FaviconDatabaseIconTypeTest,
                            ShouldBeBackwardCompatible);
   FRIEND_TEST_ALL_PREFIXES(FaviconDatabaseTest, RetainDataForPageUrls);
   FRIEND_TEST_ALL_PREFIXES(FaviconDatabaseTest,
                            RetainDataForPageUrlsExpiresRetainedFavicons);
   FRIEND_TEST_ALL_PREFIXES(FaviconDatabaseTest, Version3);
   FRIEND_TEST_ALL_PREFIXES(FaviconDatabaseTest, Version4);
   FRIEND_TEST_ALL_PREFIXES(FaviconDatabaseTest, Version5);
   FRIEND_TEST_ALL_PREFIXES(FaviconDatabaseTest, Version6);
   FRIEND_TEST_ALL_PREFIXES(FaviconDatabaseTest, Version7);
   FRIEND_TEST_ALL_PREFIXES(FaviconDatabaseTest, Version8);
   FRIEND_TEST_ALL_PREFIXES(FaviconDatabaseTest, Version9);
   FRIEND_TEST_ALL_PREFIXES(FaviconDatabaseTest, WildSchema);

   // For historical reasons, and for backward compatibility, the icon type
   // values stored in the DB are powers of two. Conversion functions
   // exposed publicly for testing.
   static int ToPersistedIconType(favicon_base::IconType icon_type);
   static favicon_base::IconType FromPersistedIconType(int icon_type);

   // `page_url_type` is stored as an int representation of the enum.
   static int ToPersistedPageUrlType(PageUrlType page_url_type);
   static PageUrlType FromPersistedPageUrlType(int page_url_type);

   // Fills `icon_mapping` with data from `statement` for `page_url`. The
   // format of the data in `statement` is an internal implementation detail.
   static void FillIconMapping(const GURL& page_url,
                               sql::Statement& statement,
                               IconMapping* icon_mapping);

   // Open database on a given filename. If the file does not exist,
   // it is created.
   // `db` is the database to open.
   // `db_name` is a path to the database file.
   sql::InitStatus OpenDatabase(sql::Database* db,
                                const base::FilePath& db_name);

   // Helper function to implement internals of Init().  This allows
   // Init() to retry in case of failure, since some failures run
   // recovery code.
   sql::InitStatus InitImpl(const base::FilePath& db_name);

   // Helper function to handle cleanup on upgrade failures.
   sql::InitStatus CantUpgradeToVersion(int cur_version);

   // Adds column for `page_url_type` to `icon_mapping` table.
   bool UpgradeToVersion9();

   // Returns true if the `favicons` database is missing a column.
   bool IsFaviconDBStructureIncorrect();

   sql::Database db_;
   sql::MetaTable meta_table_;
 };

 }  // namespace favicon

 #endif  // COMPONENTS_FAVICON_CORE_FAVICON_DATABASE_H_
	// Copyright 2012 The Chromium Authors
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#ifndef COMPONENTS_FAVICON_CORE_FAVICON_DATABASE_H_
	#define COMPONENTS_FAVICON_CORE_FAVICON_DATABASE_H_

	#include <optional>
	#include <vector>

	#include "base/feature_list.h"
	#include "base/gtest_prod_util.h"
	#include "base/memory/ref_counted.h"
	#include "components/favicon/core/favicon_types.h"
	#include "sql/database.h"
	#include "sql/init_status.h"
	#include "sql/meta_table.h"
	#include "sql/statement.h"

	namespace base {
	class FilePath;
	class RefCountedMemory;
	class Time;
	} // namespace base

	namespace url {
	class Origin;
	} // namespace url

	namespace favicon {

	// The minimum number of days after which last_requested field gets updated.
	// All earlier updates are ignored.
	static const int kFaviconUpdateLastRequestedAfterDays = 10;

	// This database interface is owned by the history backend and runs on the
	// history thread.
	class FaviconDatabase {
	public:
	FaviconDatabase();
	~FaviconDatabase();

	// Must be called after creation but before any other methods are called.
	// When not INIT_OK, no other functions should be called.
	sql::InitStatus Init(const base::FilePath& db_name);

	// Computes and records various metrics for the database. Should only be
	// called once and only upon successful Init.
	void ComputeDatabaseMetrics();

	// Transactions on the database.
	void BeginTransaction();
	void CommitTransaction();
	int transaction_nesting() const { return db_.transaction_nesting(); }
	void RollbackTransaction();

	// Vacuums the database. This will cause sqlite to defragment and collect
	// unused space in the file. It can be VERY SLOW.
	void Vacuum();

	// Release all non-essential memory associated with this database connection.
	void TrimMemory();

	// Get all on-demand favicon bitmaps that have been last requested prior to
	// `threshold`.
	std::map<favicon_base::FaviconID, IconMappingsForExpiry>
	GetOldOnDemandFavicons(base::Time threshold);

	// Favicon Bitmaps -----------------------------------------------------------

	// Returns true if there are favicon bitmaps for `icon_id`. If
	// `bitmap_id_sizes` is non NULL, sets it to a list of the favicon bitmap ids
	// and their associated pixel sizes for the favicon with `icon_id`.
	// The list contains results for the bitmaps which are cached in the
	// favicon_bitmaps table. The pixel sizes are a subset of the sizes in the
	// 'sizes' field of the favicons table for `icon_id`.
	bool GetFaviconBitmapIDSizes(
	favicon_base::FaviconID icon_id,
	std::vector<FaviconBitmapIDSize>* bitmap_id_sizes);

	// Returns true if there are any matched bitmaps for the given `icon_id`. All
	// matched results are returned if `favicon_bitmaps` is not NULL.
	bool GetFaviconBitmaps(favicon_base::FaviconID icon_id,
	std::vector<FaviconBitmap>* favicon_bitmaps);

	// Gets the last updated time, bitmap data, and pixel size of the favicon
	// bitmap at `bitmap_id`. Returns true if successful.
	bool GetFaviconBitmap(FaviconBitmapID bitmap_id,
	base::Time* last_updated,
	base::Time* last_requested,
	scoped_refptr<base::RefCountedMemory>* png_icon_data,
	gfx::Size* pixel_size);

	// Adds a bitmap component of `type` at `pixel_size` for the favicon with
	// `icon_id`. Only favicons representing a .ico file should have multiple
	// favicon bitmaps per favicon.
	// `icon_data` is the png encoded data.
	// The `type` indicates how the lifetime of this icon should be managed.
	// The `time` is used for lifetime management of the bitmap (should be Now()).
	// `pixel_size` is the pixel dimensions of `icon_data`.
	// Returns the id of the added bitmap or 0 if unsuccessful.
	FaviconBitmapID AddFaviconBitmap(
	favicon_base::FaviconID icon_id,
	scoped_refptr<base::RefCountedMemory> icon_data,
	FaviconBitmapType type,
	base::Time time,
	const gfx::Size& pixel_size);

	// Sets the bitmap data and the last updated time for the favicon bitmap at
	// `bitmap_id`. Should not be called for bitmaps of type ON_DEMAND as they
	// should never get updated (the call silently changes the type to ON_VISIT).
	// Returns true if successful.
	bool SetFaviconBitmap(FaviconBitmapID bitmap_id,
	scoped_refptr<base::RefCountedMemory> bitmap_data,
	base::Time time);

	// Sets the last_updated time for the favicon bitmap at `bitmap_id`. Should
	// not be called for bitmaps of type ON_DEMAND as last_updated time is only
	// tracked for ON_VISIT bitmaps (the call silently changes the type to
	// ON_VISIT). Returns true if successful.
	bool SetFaviconBitmapLastUpdateTime(FaviconBitmapID bitmap_id,
	base::Time time);

	// Deletes the favicon bitmap with `bitmap_id`.
	// Returns true if successful.
	bool DeleteFaviconBitmap(FaviconBitmapID bitmap_id);

	// Favicons ------------------------------------------------------------------

	// Sets the the favicon as out of date. This will set `last_updated` for all
	// of the bitmaps for `icon_id` to be out of date.
	bool SetFaviconOutOfDate(favicon_base::FaviconID icon_id);

	// Mark all favicons as out of date that have been modified at or after
	// `begin` and before `end`. This will set `last_updated` for all matching
	// bitmaps to be out of date.
	bool SetFaviconsOutOfDateBetween(base::Time begin, base::Time end);

	// Retrieves the newest `last_updated` time across all bitmaps for `icon_id`.
	// Returns true if successful and if there is at least one bitmap.
	bool GetFaviconLastUpdatedTime(favicon_base::FaviconID icon_id,
	base::Time* last_updated);

	// Mark all bitmaps of type ON_DEMAND at `icon_url` as requested at `time`.
	// This postpones their automatic eviction from the database. Not all calls
	// end up in a write into the DB:
	// - it is no-op if the bitmaps are not of type ON_DEMAND;
	// - the updates of the "last requested time" have limited frequency for each
	// particular bitmap (e.g. once per week). This limits the overhead of
	// cache management for on-demand favicons.
	// Returns true if successful.
	bool TouchOnDemandFavicon(const GURL& icon_url, base::Time time);

	// Returns the id of the entry in the favicon database with the specified
	// `icon_url` and `icon_type` that has an existing mapping to `page_origin`
	// (and 0 if no entry exists). See crbug.com/1300214 for more context.
	favicon_base::FaviconID GetFaviconIDForFaviconURL(
	const GURL& icon_url,
	favicon_base::IconType icon_type,
	const url::Origin& page_origin);

	// Returns the id of the entry in the favicon database with the specified
	// `icon_url` and `icon_type` (and 0 if no entry exists). This function does
	// not respect cross-origin partitioning and returns an entry from the cache
	// without verifying it was stored for the origin requesting it. This can leak
	// navigation history, see crbug.com/1300214 for more context.
	favicon_base::FaviconID GetFaviconIDForFaviconURL(
	const GURL& icon_url,
	favicon_base::IconType icon_type);

	// Gets the icon_url, icon_type and sizes for the specified `icon_id`.
	bool GetFaviconHeader(favicon_base::FaviconID icon_id,
	GURL* icon_url,
	favicon_base::IconType* icon_type);

	// Adds favicon with `icon_url`, `icon_type` and `favicon_sizes` to the
	// favicon db, returning its id.
	favicon_base::FaviconID AddFavicon(const GURL& icon_url,
	favicon_base::IconType icon_type);

	// Adds a favicon with a single bitmap. This call is equivalent to calling
	// AddFavicon and AddFaviconBitmap of type `type`.
	favicon_base::FaviconID AddFavicon(
	const GURL& icon_url,
	favicon_base::IconType icon_type,
	scoped_refptr<base::RefCountedMemory> icon_data,
	FaviconBitmapType type,
	base::Time time,
	const gfx::Size& pixel_size);

	// Delete the favicon with the provided id. Returns false on failure
	bool DeleteFavicon(favicon_base::FaviconID id);

	// Icon Mapping --------------------------------------------------------------
	//
	// Returns true if there is a matched icon mapping for the given page and
	// icon type.
	// The matched icon mapping is returned in the icon_mapping parameter if it is
	// not NULL.

	// Returns true if there are icon mappings for the given page and icon types.
	// The matched icon mappings are returned in the `mapping_data` parameter if
	// it is not NULL.
	bool GetIconMappingsForPageURL(
	const GURL& page_url,
	const favicon_base::IconTypeSet& required_icon_types,
	std::vector<IconMapping>* mapping_data);

	// Returns true if there is any matched icon mapping for the given page.
	// All matched icon mappings are returned in descent order of IconType if
	// mapping_data is not NULL.
	bool GetIconMappingsForPageURL(const GURL& page_url,
	std::vector<IconMapping>* mapping_data);

	// Given `url`, returns the `page_url` page mapped to an icon with
	// `required_icon_types`, where `page_url` has host = url.host(). The search
	// prioritizes `PageUrlType::kRegular` over `PageUrlType::kRedirect` on the
	// assumption that `url` is not a cross-host redirect. This enables icons
	// to be retrieved when a full URL is not available. For example,
	// `url` = http://www.google.com would match
	// `page_url` = https://www.google.com/search.
	// The returned optional will be empty if no such `page_url` exists.
	std::optional<GURL> FindBestPageURLForHost(
	const GURL& url,
	const favicon_base::IconTypeSet& required_icon_types);

	// Adds a mapping between the given `page_url` and `icon_id`. A
	// `page_url_type` must also be provided. It is not possible to store multiple
	// entries for a (`page_url`, `icon_id`) pair with different `page_url_type`s.
	// Returns the new mapping id if the adding succeeds, otherwise 0 is returned.
	IconMappingID AddIconMapping(const GURL& page_url,
	favicon_base::FaviconID icon_id,
	PageUrlType page_url_type);

	// Deletes the icon mapping entries for the given page url.
	// Returns true if the deletion succeeded.
	bool DeleteIconMappings(const GURL& page_url);

	// Deletes the icon mapping entries for the given favicon ID.
	// Returns true if the deletion succeeded.
	bool DeleteIconMappingsForFaviconId(favicon_base::FaviconID id);

	// Deletes the icon mapping with `mapping_id`.
	// Returns true if the deletion succeeded.
	bool DeleteIconMapping(IconMappingID mapping_id);

	// Checks whether a favicon is used by any URLs in the database.
	bool HasMappingFor(favicon_base::FaviconID id);

	// Returns the ids of favicons which were last updated before `time`. This
	// returns at most `max_count` ids.
	std::vector<favicon_base::FaviconID> GetFaviconsLastUpdatedBefore(
	base::Time time,
	int max_count);

	// The class to enumerate icon mappings. Use InitIconMappingEnumerator to
	// initialize.
	class IconMappingEnumerator {
	public:
	IconMappingEnumerator();

	IconMappingEnumerator(const IconMappingEnumerator&) = delete;
	IconMappingEnumerator& operator=(const IconMappingEnumerator&) = delete;

	~IconMappingEnumerator();

	// Get the next icon mapping, return false if no more are available.
	bool GetNextIconMapping(IconMapping* icon_mapping);

	private:
	friend class FaviconDatabase;

	// Used to query database and return the data for filling IconMapping in
	// each call of GetNextIconMapping().
	sql::Statement statement_;
	};

	// Return all icon mappings of the given `icon_type`.
	bool InitIconMappingEnumerator(favicon_base::IconType type,
	IconMappingEnumerator* enumerator);

	// Remove all data except that associated with the passed page urls.
	// Returns false in case of failure. A nested transaction is used,
	// so failure causes any outer transaction to be rolled back.
	bool RetainDataForPageUrls(const std::vector<GURL>& urls_to_keep);

	private:
	FRIEND_TEST_ALL_PREFIXES(FaviconDatabaseIconTypeTest,
	ShouldBeBackwardCompatible);
	FRIEND_TEST_ALL_PREFIXES(FaviconDatabaseTest, RetainDataForPageUrls);
	FRIEND_TEST_ALL_PREFIXES(FaviconDatabaseTest,
	RetainDataForPageUrlsExpiresRetainedFavicons);
	FRIEND_TEST_ALL_PREFIXES(FaviconDatabaseTest, Version3);
	FRIEND_TEST_ALL_PREFIXES(FaviconDatabaseTest, Version4);
	FRIEND_TEST_ALL_PREFIXES(FaviconDatabaseTest, Version5);
	FRIEND_TEST_ALL_PREFIXES(FaviconDatabaseTest, Version6);
	FRIEND_TEST_ALL_PREFIXES(FaviconDatabaseTest, Version7);
	FRIEND_TEST_ALL_PREFIXES(FaviconDatabaseTest, Version8);
	FRIEND_TEST_ALL_PREFIXES(FaviconDatabaseTest, Version9);
	FRIEND_TEST_ALL_PREFIXES(FaviconDatabaseTest, WildSchema);

	// For historical reasons, and for backward compatibility, the icon type
	// values stored in the DB are powers of two. Conversion functions
	// exposed publicly for testing.
	static int ToPersistedIconType(favicon_base::IconType icon_type);
	static favicon_base::IconType FromPersistedIconType(int icon_type);

	// `page_url_type` is stored as an int representation of the enum.
	static int ToPersistedPageUrlType(PageUrlType page_url_type);
	static PageUrlType FromPersistedPageUrlType(int page_url_type);

	// Fills `icon_mapping` with data from `statement` for `page_url`. The
	// format of the data in `statement` is an internal implementation detail.
	static void FillIconMapping(const GURL& page_url,
	sql::Statement& statement,
	IconMapping* icon_mapping);

	// Open database on a given filename. If the file does not exist,
	// it is created.
	// `db` is the database to open.
	// `db_name` is a path to the database file.
	sql::InitStatus OpenDatabase(sql::Database* db,
	const base::FilePath& db_name);

	// Helper function to implement internals of Init(). This allows
	// Init() to retry in case of failure, since some failures run
	// recovery code.
	sql::InitStatus InitImpl(const base::FilePath& db_name);

	// Helper function to handle cleanup on upgrade failures.
	sql::InitStatus CantUpgradeToVersion(int cur_version);

	// Adds column for `page_url_type` to `icon_mapping` table.
	bool UpgradeToVersion9();

	// Returns true if the `favicons` database is missing a column.
	bool IsFaviconDBStructureIncorrect();

	sql::Database db_;
	sql::MetaTable meta_table_;
	};

	} // namespace favicon

	#endif // COMPONENTS_FAVICON_CORE_FAVICON_DATABASE_H_