/*

 * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.

 * Copyright (C) 2007 Justin Haygood (jhaygood@reaktix.com)

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY

 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY

 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

 */

#ifndef IconDatabase_h

#define IconDatabase_h

#include "StringHash.h"

#include "Timer.h"

#include <wtf/HashMap.h>

#include <wtf/HashSet.h>

#include <wtf/Noncopyable.h>

#include <wtf/OwnPtr.h>

#if ENABLE(ICONDATABASE)

#include "SQLiteDatabase.h"

#include <wtf/Threading.h>

#endif

namespace WebCore { 

class DocumentLoader;

class Image;

class IntSize;

class IconDatabaseClient;

class IconRecord;

class IconSnapshot;

class KURL;

class PageURLRecord;

class PageURLSnapshot;

class SharedBuffer;

#if ENABLE(ICONDATABASE)

class SQLTransaction;

#endif

enum IconLoadDecision {

    IconLoadYes,

    IconLoadNo,

    IconLoadUnknown

};

class IconDatabase : public Noncopyable {

// *** Main Thread Only ***

public:

    void setClient(IconDatabaseClient*);

    bool open(const String& path);

    void close();

    void removeAllIcons();

    Image* iconForPageURL(const String&, const IntSize&);

    void readIconForPageURLFromDisk(const String&);

    String iconURLForPageURL(const String&);

    Image* defaultIcon(const IntSize&);

    void retainIconForPageURL(const String&);

    void releaseIconForPageURL(const String&);

    void setIconDataForIconURL(PassRefPtr<SharedBuffer> data, const String&);

    void setIconURLForPageURL(const String& iconURL, const String& pageURL);

    IconLoadDecision loadDecisionForIconURL(const String&, DocumentLoader*);

    bool iconDataKnownForIconURL(const String&);

    void setEnabled(bool enabled);

    bool isEnabled() const;

    void setPrivateBrowsingEnabled(bool flag);

    bool isPrivateBrowsingEnabled() const;

    static void delayDatabaseCleanup();

    static void allowDatabaseCleanup();

    static void checkIntegrityBeforeOpening();

    // Support for WebCoreStatistics in WebKit

    size_t pageURLMappingCount();

    size_t retainedPageURLCount();

    size_t iconRecordCount();

    size_t iconRecordCountWithData();

private:

    IconDatabase();

    ~IconDatabase();

    friend IconDatabase* iconDatabase();

#if ENABLE(ICONDATABASE)

    static void notifyPendingLoadDecisionsOnMainThread(void*);

    void notifyPendingLoadDecisions();

    void wakeSyncThread();

    void scheduleOrDeferSyncTimer();

    void syncTimerFired(Timer<IconDatabase>*);

    Timer<IconDatabase> m_syncTimer;

    ThreadIdentifier m_syncThread;

    bool m_syncThreadRunning;

    HashSet<RefPtr<DocumentLoader> > m_loadersPendingDecision;

    RefPtr<IconRecord> m_defaultIconRecord;

#endif // ENABLE(ICONDATABASE)

// *** Any Thread ***

public:

    bool isOpen() const;

    String databasePath() const;

    static String defaultDatabaseFilename();

#if ENABLE(ICONDATABASE)

private:

    PassRefPtr<IconRecord> getOrCreateIconRecord(const String& iconURL);

    PageURLRecord* getOrCreatePageURLRecord(const String& pageURL);

    bool m_isEnabled;

    bool m_privateBrowsingEnabled;

    mutable Mutex m_syncLock;

    ThreadCondition m_syncCondition;

    String m_databaseDirectory;

    // Holding m_syncLock is required when accessing m_completeDatabasePath

    String m_completeDatabasePath;

    bool m_threadTerminationRequested;

    bool m_removeIconsRequested;

    bool m_iconURLImportComplete;

    Mutex m_urlAndIconLock;

    // Holding m_urlAndIconLock is required when accessing any of the following data structures or the objects they contain

    HashMap<String, IconRecord*> m_iconURLToRecordMap;

    HashMap<String, PageURLRecord*> m_pageURLToRecordMap;

    HashSet<String> m_retainedPageURLs;

    Mutex m_pendingSyncLock;

    // Holding m_pendingSyncLock is required when accessing any of the following data structures

    HashMap<String, PageURLSnapshot> m_pageURLsPendingSync;

    HashMap<String, IconSnapshot> m_iconsPendingSync;

    Mutex m_pendingReadingLock;    

    // Holding m_pendingSyncLock is required when accessing any of the following data structures - when dealing with IconRecord*s, holding m_urlAndIconLock is also required

    HashSet<String> m_pageURLsPendingImport;

    HashSet<String> m_pageURLsInterestedInIcons;

    HashSet<IconRecord*> m_iconsPendingReading;

#endif // ENABLE(ICONDATABASE)

// *** Sync Thread Only ***

public:

    // Should be used only on the sync thread and only by the Safari 2 Icons import procedure

    void importIconURLForPageURL(const String& iconURL, const String& pageURL);

    void importIconDataForIconURL(PassRefPtr<SharedBuffer> data, const String& iconURL);

    bool shouldStopThreadActivity() const;

#if ENABLE(ICONDATABASE)

private:    

    static void* iconDatabaseSyncThreadStart(void *);

    void* iconDatabaseSyncThread();

    // The following block of methods are called exclusively by the sync thread to manage i/o to and from the database

    // Each method should periodically monitor m_threadTerminationRequested when it makes sense to return early on shutdown

    void performOpenInitialization();

    bool checkIntegrity();

    void performURLImport();

    void* syncThreadMainLoop();

    bool readFromDatabase();

    bool writeToDatabase();

    void pruneUnretainedIcons();

    void checkForDanglingPageURLs(bool pruneIfFound);

    void removeAllIconsOnThread();

    void deleteAllPreparedStatements();

    void* cleanupSyncThread();

    // Record (on disk) whether or not Safari 2-style icons were imported (once per dataabse)

    bool imported();

    void setImported(bool);

    bool m_initialPruningComplete;

    void setIconURLForPageURLInSQLDatabase(const String&, const String&);

    void setIconIDForPageURLInSQLDatabase(int64_t, const String&);

    void removePageURLFromSQLDatabase(const String& pageURL);

    int64_t getIconIDForIconURLFromSQLDatabase(const String& iconURL);

    int64_t addIconURLToSQLDatabase(const String&);

    PassRefPtr<SharedBuffer> getImageDataForIconURLFromSQLDatabase(const String& iconURL);

    void removeIconFromSQLDatabase(const String& iconURL);

    void writeIconSnapshotToSQLDatabase(const IconSnapshot&);    

    // The client is set by the main thread before the thread starts, and from then on is only used by the sync thread

    IconDatabaseClient* m_client;

    SQLiteDatabase m_syncDB;

    // Track whether the "Safari 2" import is complete and/or set in the database

    bool m_imported;

    bool m_isImportedSet;

    OwnPtr<SQLiteStatement> m_setIconIDForPageURLStatement;

    OwnPtr<SQLiteStatement> m_removePageURLStatement;

    OwnPtr<SQLiteStatement> m_getIconIDForIconURLStatement;

    OwnPtr<SQLiteStatement> m_getImageDataForIconURLStatement;

    OwnPtr<SQLiteStatement> m_addIconToIconInfoStatement;

    OwnPtr<SQLiteStatement> m_addIconToIconDataStatement;

    OwnPtr<SQLiteStatement> m_getImageDataStatement;

    OwnPtr<SQLiteStatement> m_deletePageURLsForIconURLStatement;

    OwnPtr<SQLiteStatement> m_deleteIconFromIconInfoStatement;

    OwnPtr<SQLiteStatement> m_deleteIconFromIconDataStatement;

    OwnPtr<SQLiteStatement> m_updateIconInfoStatement;

    OwnPtr<SQLiteStatement> m_updateIconDataStatement;

    OwnPtr<SQLiteStatement> m_setIconInfoStatement;

    OwnPtr<SQLiteStatement> m_setIconDataStatement;

#endif // ENABLE(ICONDATABASE)

};

// Function to obtain the global icon database.

IconDatabase* iconDatabase();

} // namespace WebCore

#endif // IconDatabase_h