databasetracker.cpp

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

/*
 * Copyright (C) 2007, 2008 Apple Inc. All rights reserved.
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 * 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
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 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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 */

#include "config.h"
#include "DatabaseTracker.h"

#include "ChromeClient.h"
#include "Database.h"
#include "DatabaseTrackerClient.h"
#include "Document.h"
#include "FileSystem.h"
#include "Logging.h"
#include "OriginQuotaManager.h"
#include "Page.h"
#include "SecurityOrigin.h"
#include "SecurityOriginHash.h"
#include "SQLiteStatement.h"
#include <wtf/MainThread.h>
#include <wtf/StdLibExtras.h>

using namespace std;

namespace WebCore {

OriginQuotaManager& DatabaseTracker::originQuotaManager()
{
    populateOrigins();
    ASSERT(m_quotaManager);
    return *m_quotaManager;
}

DatabaseTracker& DatabaseTracker::tracker()
{
    DEFINE_STATIC_LOCAL(DatabaseTracker, tracker, ());
    return tracker;
}

DatabaseTracker::DatabaseTracker()
    : m_client(0)
    , m_proposedDatabase(0)
#ifndef NDEBUG
    , m_thread(currentThread())
#endif
{
}

void DatabaseTracker::setDatabaseDirectoryPath(const String& path)
{
    ASSERT(currentThread() == m_thread);
    ASSERT(!m_database.isOpen());
    m_databaseDirectoryPath = path;
}

const String& DatabaseTracker::databaseDirectoryPath() const
{
    ASSERT(currentThread() == m_thread);
    return m_databaseDirectoryPath;
}

String DatabaseTracker::trackerDatabasePath() const
{
    ASSERT(currentThread() == m_thread);
    if (m_databaseDirectoryPath.isEmpty())
        return String();
    return pathByAppendingComponent(m_databaseDirectoryPath, "Databases.db");
}

void DatabaseTracker::openTrackerDatabase(bool createIfDoesNotExist)
{
    ASSERT(currentThread() == m_thread);

    if (m_database.isOpen())
        return;

    String databasePath = trackerDatabasePath();
    if (databasePath.isEmpty())
        return;

    if (!createIfDoesNotExist && !fileExists(databasePath))
        return;

    makeAllDirectories(m_databaseDirectoryPath);
    if (!m_database.open(databasePath)) {
        // FIXME: What do do here?
        return;
    }
    if (!m_database.tableExists("Origins")) {
        if (!m_database.executeCommand("CREATE TABLE Origins (origin TEXT UNIQUE ON CONFLICT REPLACE, quota INTEGER NOT NULL ON CONFLICT FAIL);")) {
            // FIXME: and here
        }
    }
    if (!m_database.tableExists("Databases")) {
        if (!m_database.executeCommand("CREATE TABLE Databases (guid INTEGER PRIMARY KEY AUTOINCREMENT, origin TEXT, name TEXT, displayName TEXT, estimatedSize INTEGER, path TEXT);")) {
            // FIXME: and here
        }
    }
}

bool DatabaseTracker::canEstablishDatabase(Document* document, const String& name, const String& displayName, unsigned long estimatedSize)
{
    ASSERT(currentThread() == m_thread);

    // Populate the origins before we establish a database; this guarantees that quotaForOrigin
    // can run on the database thread later.
    populateOrigins();

    SecurityOrigin* origin = document->securityOrigin();

    // Since we're imminently opening a database within this Document's origin, make sure this origin is being tracked by the QuotaTracker
    // by fetching it's current usage now
    unsigned long long usage = usageForOrigin(origin);
    
    // If a database already exists, ignore the passed-in estimated size and say it's OK.
    if (hasEntryForDatabase(origin, name))
        return true;

    // If the database will fit, allow its creation.
    unsigned long long requirement = usage + max(1UL, estimatedSize);
    if (requirement < usage)
        return false; // If the estimated size is so big it causes an overflow, don't allow creation.
    if (requirement <= quotaForOrigin(origin))
        return true;

    // Give the chrome client a chance to increase the quota.
    // Temporarily make the details of the proposed database available, so the client can get at them.
    Page* page = document->page();
    if (!page)
        return false;
    pair<SecurityOrigin*, DatabaseDetails> details(origin, DatabaseDetails(name, displayName, estimatedSize, 0));
    m_proposedDatabase = &details;
    page->chrome()->client()->exceededDatabaseQuota(document->frame(), name);
    m_proposedDatabase = 0;

    // If the database will fit now, allow its creation.
    return requirement <= quotaForOrigin(origin);
}

bool DatabaseTracker::hasEntryForOrigin(SecurityOrigin* origin)
{
    ASSERT(currentThread() == m_thread);
    populateOrigins();
    MutexLocker lockQuotaMap(m_quotaMapGuard);
    return m_quotaMap->contains(origin);
}

bool DatabaseTracker::hasEntryForDatabase(SecurityOrigin* origin, const String& databaseIdentifier)
{
    ASSERT(currentThread() == m_thread);
    openTrackerDatabase(false);
    if (!m_database.isOpen())
        return false;
    SQLiteStatement statement(m_database, "SELECT guid FROM Databases WHERE origin=? AND name=?;");

    if (statement.prepare() != SQLResultOk)
        return false;

    statement.bindText(1, origin->databaseIdentifier());
    statement.bindText(2, databaseIdentifier);

    return statement.step() == SQLResultRow;
}

String DatabaseTracker::originPath(SecurityOrigin* origin) const
{
    ASSERT(currentThread() == m_thread);
    if (m_databaseDirectoryPath.isEmpty())
        return String();
    return pathByAppendingComponent(m_databaseDirectoryPath, origin->databaseIdentifier());
}

String DatabaseTracker::fullPathForDatabase(SecurityOrigin* origin, const String& name, bool createIfNotExists)
{
    ASSERT(currentThread() == m_thread);

    if (m_proposedDatabase && m_proposedDatabase->first == origin && m_proposedDatabase->second.name() == name)
        return String();

    String originIdentifier = origin->databaseIdentifier();
    String originPath = this->originPath(origin);
    
    // Make sure the path for this SecurityOrigin exists
    if (createIfNotExists && !makeAllDirectories(originPath))
        return String();
    
    // See if we have a path for this database yet
    openTrackerDatabase(false);
    if (!m_database.isOpen())
        return String();
    SQLiteStatement statement(m_database, "SELECT path FROM Databases WHERE origin=? AND name=?;");

    if (statement.prepare() != SQLResultOk)
        return String();

    statement.bindText(1, originIdentifier);
    statement.bindText(2, name);

    int result = statement.step();

    if (result == SQLResultRow)
        return pathByAppendingComponent(originPath, statement.getColumnText(0));
    if (!createIfNotExists)
        return String();
        
    if (result != SQLResultDone) {
        LOG_ERROR("Failed to retrieve filename from Database Tracker for origin %s, name %s", origin->databaseIdentifier().ascii().data(), name.ascii().data());
        return String();
    }
    statement.finalize();
    
    SQLiteStatement sequenceStatement(m_database, "SELECT seq FROM sqlite_sequence WHERE name='Databases';");

    // FIXME: More informative error handling here, even though these steps should never fail
    if (sequenceStatement.prepare() != SQLResultOk)
        return String();
    result = sequenceStatement.step();

    // This has a range of 2^63 and starts at 0 for every time a user resets Safari -
    // I can't imagine it'd over overflow
    int64_t seq = 0;
    if (result == SQLResultRow) {
        seq = sequenceStatement.getColumnInt64(0);
    } else if (result != SQLResultDone)
        return String();
    sequenceStatement.finalize();

    String filename;
    do {
        ++seq;
        filename = pathByAppendingComponent(originPath, String::format("%016llx.db", seq));
    } while (fileExists(filename));

    if (!addDatabase(origin, name, String::format("%016llx.db", seq)))
        return String();

    // If this origin's quota is being tracked (open handle to a database in this origin), add this new database
    // to the quota manager now
    {
        Locker<OriginQuotaManager> locker(originQuotaManager());
        if (originQuotaManager().tracksOrigin(origin))
            originQuotaManager().addDatabase(origin, name, filename);
    }
    
    return filename;
}

void DatabaseTracker::populateOrigins()
{
    if (m_quotaMap)
        return;

    ASSERT(currentThread() == m_thread);

    m_quotaMap.set(new QuotaMap);
    m_quotaManager.set(new OriginQuotaManager);

    openTrackerDatabase(false);
    if (!m_database.isOpen())
        return;

    SQLiteStatement statement(m_database, "SELECT origin, quota FROM Origins");

    if (statement.prepare() != SQLResultOk)
        return;

    int result;
    while ((result = statement.step()) == SQLResultRow) {
        RefPtr<SecurityOrigin> origin = SecurityOrigin::createFromDatabaseIdentifier(statement.getColumnText(0));
        m_quotaMap->set(origin.get(), statement.getColumnInt64(1));
    }

    if (result != SQLResultDone)
        LOG_ERROR("Failed to read in all origins from the database");
}

void DatabaseTracker::origins(Vector<RefPtr<SecurityOrigin> >& result)
{
    ASSERT(currentThread() == m_thread);
    populateOrigins();
    MutexLocker lockQuotaMap(m_quotaMapGuard);
    copyKeysToVector(*m_quotaMap, result);
}

bool DatabaseTracker::databaseNamesForOrigin(SecurityOrigin* origin, Vector<String>& resultVector)
{
    ASSERT(currentThread() == m_thread);
    openTrackerDatabase(false);
    if (!m_database.isOpen())
        return false;

    SQLiteStatement statement(m_database, "SELECT name FROM Databases where origin=?;");

    if (statement.prepare() != SQLResultOk)
        return false;

    statement.bindText(1, origin->databaseIdentifier());

    int result;
    while ((result = statement.step()) == SQLResultRow)
        resultVector.append(statement.getColumnText(0));

    if (result != SQLResultDone) {
        LOG_ERROR("Failed to retrieve all database names for origin %s", origin->databaseIdentifier().ascii().data());
        return false;
    }

    return true;
}

DatabaseDetails DatabaseTracker::detailsForNameAndOrigin(const String& name, SecurityOrigin* origin)
{
    ASSERT(currentThread() == m_thread);

    if (m_proposedDatabase && m_proposedDatabase->first == origin && m_proposedDatabase->second.name() == name)
        return m_proposedDatabase->second;

    String originIdentifier = origin->databaseIdentifier();

    openTrackerDatabase(false);
    if (!m_database.isOpen())
        return DatabaseDetails();
    SQLiteStatement statement(m_database, "SELECT displayName, estimatedSize FROM Databases WHERE origin=? AND name=?");
    if (statement.prepare() != SQLResultOk)
        return DatabaseDetails();
   
    statement.bindText(1, originIdentifier);
    statement.bindText(2, name);
    
    int result = statement.step();
    if (result == SQLResultDone)
        return DatabaseDetails();
    
    if (result != SQLResultRow) {
        LOG_ERROR("Error retrieving details for database %s in origin %s from tracker database", name.ascii().data(), originIdentifier.ascii().data());
        return DatabaseDetails();
    }
    
    return DatabaseDetails(name, statement.getColumnText(0), statement.getColumnInt64(1), usageForDatabase(name, origin));
}

void DatabaseTracker::setDatabaseDetails(SecurityOrigin* origin, const String& name, const String& displayName, unsigned long estimatedSize)
{
    ASSERT(currentThread() == m_thread);

    String originIdentifier = origin->databaseIdentifier();
    int64_t guid = 0;
    
    openTrackerDatabase(true);
    if (!m_database.isOpen())
        return;
    SQLiteStatement statement(m_database, "SELECT guid FROM Databases WHERE origin=? AND name=?");
    if (statement.prepare() != SQLResultOk)
        return;
        
    statement.bindText(1, originIdentifier);
    statement.bindText(2, name);
    
    int result = statement.step();
    if (result == SQLResultRow)
        guid = statement.getColumnInt64(0);
    statement.finalize();

    if (guid == 0) {
        if (result != SQLResultDone)
            LOG_ERROR("Error to determing existence of database %s in origin %s in tracker database", name.ascii().data(), originIdentifier.ascii().data());
        else {
            // This case should never occur - we should never be setting database details for a database that doesn't already exist in the tracker
            // But since the tracker file is an external resource not under complete control of our code, it's somewhat invalid to make this an ASSERT case
            // So we'll print an error instead
            LOG_ERROR("Could not retrieve guid for database %s in origin %s from the tracker database - it is invalid to set database details on a database that doesn't already exist in the tracker",
                       name.ascii().data(), originIdentifier.ascii().data());
        }
        return;
    }
    
    SQLiteStatement updateStatement(m_database, "UPDATE Databases SET displayName=?, estimatedSize=? WHERE guid=?");
    if (updateStatement.prepare() != SQLResultOk)
        return;
    
    updateStatement.bindText(1, displayName);
    updateStatement.bindInt64(2, estimatedSize);
    updateStatement.bindInt64(3, guid);
    
    if (updateStatement.step() != SQLResultDone) {
        LOG_ERROR("Failed to update details for database %s in origin %s", name.ascii().data(), originIdentifier.ascii().data());
        return;  
    }
    
    if (m_client)
        m_client->dispatchDidModifyDatabase(origin, name);
}