icondatabase.cpp

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            MutexLocker locker(m_pendingReadingLock);
            m_iconsPendingReading.remove(iconRecord.get());
        }
        
        // And mark this mapping to be added to the database
        if (!m_privateBrowsingEnabled) {
            MutexLocker locker(m_pendingSyncLock);
            m_pageURLsPendingSync.set(pageURL, pageRecord->snapshot());
            
            // If the icon is on its last ref, mark it for deletion
            if (iconRecord && iconRecord->hasOneRef())
                m_iconsPendingSync.set(iconRecord->iconURL(), iconRecord->snapshot(true));
        }
    }

    // Since this mapping is new, send the notification out - but not if we're on the sync thread because that implies this mapping
    // comes from the initial import which we don't want notifications for
    if (!IS_ICON_SYNC_THREAD()) {
        // Start the timer to commit this change - or further delay the timer if it was already started
        scheduleOrDeferSyncTimer();
        
        LOG(IconDatabase, "Dispatching notification that we changed an icon mapping for url %s", urlForLogging(pageURL).ascii().data());
        AutodrainedPool pool;
        m_client->dispatchDidAddIconForPageURL(pageURL);
    }
}

IconLoadDecision IconDatabase::loadDecisionForIconURL(const String& iconURL, DocumentLoader* notificationDocumentLoader)
{
    ASSERT_NOT_SYNC_THREAD();

    if (!isOpen() || iconURL.isEmpty())
        return IconLoadNo;
    
    // If we have a IconRecord, it should also have its timeStamp marked because there is only two times when we create the IconRecord:
    // 1 - When we read the icon urls from disk, getting the timeStamp at the same time
    // 2 - When we get a new icon from the loader, in which case the timestamp is set at that time
    {
        MutexLocker locker(m_urlAndIconLock);
        if (IconRecord* icon = m_iconURLToRecordMap.get(iconURL)) {
            LOG(IconDatabase, "Found expiration time on a present icon based on existing IconRecord");
            return (int)currentTime() - icon->getTimestamp() > iconExpirationTime ? IconLoadYes : IconLoadNo;
        }
    }
    
    // If we don't have a record for it, but we *have* imported all iconURLs from disk, then we should load it now
    MutexLocker readingLocker(m_pendingReadingLock);
    if (m_iconURLImportComplete)
        return IconLoadYes;
        
    // Otherwise - since we refuse to perform I/O on the main thread to find out for sure - we return the answer that says
    // "You might be asked to load this later, so flag that"
    LOG(IconDatabase, "Don't know if we should load %s or not - adding %p to the set of document loaders waiting on a decision", iconURL.ascii().data(), notificationDocumentLoader);
    m_loadersPendingDecision.add(notificationDocumentLoader);    

    return IconLoadUnknown;
}

bool IconDatabase::iconDataKnownForIconURL(const String& iconURL)
{
    ASSERT_NOT_SYNC_THREAD();
    
    MutexLocker locker(m_urlAndIconLock);
    if (IconRecord* icon = m_iconURLToRecordMap.get(iconURL))
        return icon->imageDataStatus() != ImageDataStatusUnknown;

    return false;
}

void IconDatabase::setEnabled(bool enabled)
{
    ASSERT_NOT_SYNC_THREAD();
    
    if (!enabled && isOpen())
        close();
    m_isEnabled = enabled;
}

bool IconDatabase::isEnabled() const
{
    ASSERT_NOT_SYNC_THREAD();
    
     return m_isEnabled;
}

void IconDatabase::setPrivateBrowsingEnabled(bool flag)
{
    m_privateBrowsingEnabled = flag;
}

bool IconDatabase::isPrivateBrowsingEnabled() const
{
    return m_privateBrowsingEnabled;
}

void IconDatabase::delayDatabaseCleanup()
{
    ++databaseCleanupCounter;
    if (databaseCleanupCounter == 1)
        LOG(IconDatabase, "Database cleanup is now DISABLED");
}

void IconDatabase::allowDatabaseCleanup()
{
    if (--databaseCleanupCounter < 0)
        databaseCleanupCounter = 0;
    if (databaseCleanupCounter == 0)
        LOG(IconDatabase, "Database cleanup is now ENABLED");
}

void IconDatabase::checkIntegrityBeforeOpening()
{
    checkIntegrityOnOpen = true;
}

size_t IconDatabase::pageURLMappingCount()
{
    MutexLocker locker(m_urlAndIconLock);
    return m_pageURLToRecordMap.size();
}

size_t IconDatabase::retainedPageURLCount()
{
    MutexLocker locker(m_urlAndIconLock);
    return m_retainedPageURLs.size();
}

size_t IconDatabase::iconRecordCount()
{
    MutexLocker locker(m_urlAndIconLock);
    return m_iconURLToRecordMap.size();
}

size_t IconDatabase::iconRecordCountWithData()
{
    MutexLocker locker(m_urlAndIconLock);
    size_t result = 0;
    
    HashMap<String, IconRecord*>::iterator i = m_iconURLToRecordMap.begin();
    HashMap<String, IconRecord*>::iterator end = m_iconURLToRecordMap.end();
    
    for (; i != end; ++i)
        result += ((*i).second->imageDataStatus() == ImageDataStatusPresent);
            
    return result;
}

IconDatabase::IconDatabase()
    : m_syncThreadRunning(false)
    , m_defaultIconRecord(0)
    , m_isEnabled(false)
    , m_privateBrowsingEnabled(false)
    , m_threadTerminationRequested(false)
    , m_removeIconsRequested(false)
    , m_iconURLImportComplete(false)
    , m_initialPruningComplete(false)
    , m_client(defaultClient())
    , m_imported(false)
    , m_isImportedSet(false)
{
#if PLATFORM(DARWIN)
    ASSERT(pthread_main_np());
#endif
}

IconDatabase::~IconDatabase()
{
    ASSERT_NOT_REACHED();
}

void IconDatabase::notifyPendingLoadDecisionsOnMainThread(void* context)
{
    static_cast<IconDatabase*>(context)->notifyPendingLoadDecisions();
}

void IconDatabase::notifyPendingLoadDecisions()
{
    ASSERT_NOT_SYNC_THREAD();
    
    // This method should only be called upon completion of the initial url import from the database
    ASSERT(m_iconURLImportComplete);
    LOG(IconDatabase, "Notifying all DocumentLoaders that were waiting on a load decision for thier icons");
    
    HashSet<RefPtr<DocumentLoader> >::iterator i = m_loadersPendingDecision.begin();
    HashSet<RefPtr<DocumentLoader> >::iterator end = m_loadersPendingDecision.end();
    
    for (; i != end; ++i)
        if ((*i)->refCount() > 1)
            (*i)->iconLoadDecisionAvailable();
            
    m_loadersPendingDecision.clear();
}

void IconDatabase::wakeSyncThread()
{
    MutexLocker locker(m_syncLock);
    m_syncCondition.signal();
}

void IconDatabase::scheduleOrDeferSyncTimer()
{
    ASSERT_NOT_SYNC_THREAD();
    if (!m_syncTimer)
        m_syncTimer.set(new Timer<IconDatabase>(this, &IconDatabase::syncTimerFired));

    m_syncTimer->startOneShot(updateTimerDelay);
}

void IconDatabase::syncTimerFired(Timer<IconDatabase>*)
{
    ASSERT_NOT_SYNC_THREAD();
    wakeSyncThread();
}

// ******************
// *** Any Thread ***
// ******************

bool IconDatabase::isOpen() const
{
    MutexLocker locker(m_syncLock);
    return m_syncDB.isOpen();
}

String IconDatabase::databasePath() const
{
    MutexLocker locker(m_syncLock);
    return m_completeDatabasePath.copy();
}

String IconDatabase::defaultDatabaseFilename()
{
    DEFINE_STATIC_LOCAL(String, defaultDatabaseFilename, ("WebpageIcons.db"));
    return defaultDatabaseFilename.copy();
}

// Unlike getOrCreatePageURLRecord(), getOrCreateIconRecord() does not mark the icon as "interested in import"
PassRefPtr<IconRecord> IconDatabase::getOrCreateIconRecord(const String& iconURL)
{
    // Clients of getOrCreateIconRecord() are required to acquire the m_urlAndIconLock before calling this method
    ASSERT(!m_urlAndIconLock.tryLock());

    if (IconRecord* icon = m_iconURLToRecordMap.get(iconURL))
        return icon;

    RefPtr<IconRecord> newIcon = IconRecord::create(iconURL);
    m_iconURLToRecordMap.set(iconURL, newIcon.get());

    return newIcon.release();
}

// This method retrieves the existing PageURLRecord, or creates a new one and marks it as "interested in the import" for later notification
PageURLRecord* IconDatabase::getOrCreatePageURLRecord(const String& pageURL)
{
    // Clients of getOrCreatePageURLRecord() are required to acquire the m_urlAndIconLock before calling this method
    ASSERT(!m_urlAndIconLock.tryLock());

    if (pageURL.isEmpty())
        return 0;

    PageURLRecord* pageRecord = m_pageURLToRecordMap.get(pageURL);
    
    MutexLocker locker(m_pendingReadingLock);
    if (!m_iconURLImportComplete) {
        // If the initial import of all URLs hasn't completed and we have no page record, we assume we *might* know about this later and create a record for it
        if (!pageRecord) {
            LOG(IconDatabase, "Creating new PageURLRecord for pageURL %s", urlForLogging(pageURL).ascii().data());
            pageRecord = new PageURLRecord(pageURL);
            m_pageURLToRecordMap.set(pageURL, pageRecord);
        }

        // If the pageRecord for this page does not have an iconRecord attached to it, then it is a new pageRecord still awaiting the initial import
        // Mark the URL as "interested in the result of the import" then bail
        if (!pageRecord->iconRecord()) {
            m_pageURLsPendingImport.add(pageURL);
            return 0;
        }
    }

    // We've done the initial import of all URLs known in the database.  If this record doesn't exist now, it never will    
     return pageRecord;
}


// ************************
// *** Sync Thread Only ***
// ************************

void IconDatabase::importIconURLForPageURL(const String& iconURL, const String& pageURL)
{
    ASSERT_ICON_SYNC_THREAD();
    
    // This function is only for setting actual existing url mappings so assert that neither of these URLs are empty
    ASSERT(!iconURL.isEmpty() && !pageURL.isEmpty());
    
    setIconURLForPageURLInSQLDatabase(iconURL, pageURL);    
}

void IconDatabase::importIconDataForIconURL(PassRefPtr<SharedBuffer> data, const String& iconURL)
{
    ASSERT_ICON_SYNC_THREAD();
    
    ASSERT(!iconURL.isEmpty());

    writeIconSnapshotToSQLDatabase(IconSnapshot(iconURL, (int)currentTime(), data.get()));
}

bool IconDatabase::shouldStopThreadActivity() const
{
    ASSERT_ICON_SYNC_THREAD();