root/Source/modules/webdatabase/DatabaseBackendBase.cpp

DEFINITIONS

1. formatErrorMessage
2. retrieveTextResultFromDatabase
3. setTextValueInDatabase
4. guidMutex
5. guidToVersionMap
6. updateGuidVersionMap
7. guidToDatabaseMap
8. guidForOriginAndName
9. databaseInfoTableName
10. m_isSyncDatabase
11. trace
12. closeDatabase
13. version
14. m_openSucceeded
15. setOpenSucceeded
16. performOpenAndVerify
17. securityOrigin
18. stringIdentifier
19. displayName
20. estimatedSize
21. fileName
22. getVersionFromDatabase
23. setVersionInDatabase
24. setExpectedVersion
25. getCachedVersion
26. setCachedVersion
27. getActualVersionForTransaction
28. disableAuthorizer
29. enableAuthorizer
30. setAuthorizerPermissions
31. lastActionChangedDatabase
32. lastActionWasInsert
33. resetDeletes
34. hadDeletes
35. resetAuthorizer
36. maximumSize
37. incrementalVacuumIfNeeded
38. interrupt
39. isInterrupted
40. reportOpenDatabaseResult
41. reportChangeVersionResult
42. reportStartTransactionResult
43. reportCommitTransactionResult
44. reportExecuteStatementResult
45. reportVacuumDatabaseResult
46. logErrorMessage
47. executionContext

/*
 * Copyright (C) 2011 Google Inc. All rights reserved.
 * Copyright (C) 2013 Apple Inc. All rights reserved.
 *
 * 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.
 * 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
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS 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.
 */

#include "config.h"
#include "modules/webdatabase/DatabaseBackendBase.h"

#include "core/dom/ExceptionCode.h"
#include "core/dom/ExecutionContext.h"
#include "platform/Logging.h"
#include "modules/webdatabase/DatabaseAuthorizer.h"
#include "modules/webdatabase/DatabaseBase.h"
#include "modules/webdatabase/DatabaseContext.h"
#include "modules/webdatabase/DatabaseManager.h"
#include "modules/webdatabase/DatabaseTracker.h"
#include "modules/webdatabase/sqlite/SQLiteStatement.h"
#include "modules/webdatabase/sqlite/SQLiteTransaction.h"
#include "platform/weborigin/DatabaseIdentifier.h"
#include "public/platform/Platform.h"
#include "public/platform/WebDatabaseObserver.h"
#include "wtf/HashMap.h"
#include "wtf/HashSet.h"
#include "wtf/PassRefPtr.h"
#include "wtf/StdLibExtras.h"
#include "wtf/text/CString.h"
#include "wtf/text/StringHash.h"

// Registering "opened" databases with the DatabaseTracker
// =======================================================
// The DatabaseTracker maintains a list of databases that have been
// "opened" so that the client can call interrupt or delete on every database
// associated with a DatabaseContext.
//
// We will only call DatabaseTracker::addOpenDatabase() to add the database
// to the tracker as opened when we've succeeded in opening the database,
// and will set m_opened to true. Similarly, we only call
// DatabaseTracker::removeOpenDatabase() to remove the database from the
// tracker when we set m_opened to false in closeDatabase(). This sets up
// a simple symmetry between open and close operations, and a direct
// correlation to adding and removing databases from the tracker's list,
// thus ensuring that we have a correct list for the interrupt and
// delete operations to work on.
//
// The only databases instances not tracked by the tracker's open database
// list are the ones that have not been added yet, or the ones that we
// attempted an open on but failed to. Such instances only exist in the
// DatabaseServer's factory methods for creating database backends.
//
// The factory methods will either call openAndVerifyVersion() or
// performOpenAndVerify(). These methods will add the newly instantiated
// database backend if they succeed in opening the requested database.
// In the case of failure to open the database, the factory methods will
// simply discard the newly instantiated database backend when they return.
// The ref counting mechanims will automatically destruct the un-added
// (and un-returned) databases instances.

namespace WebCore {

static const char versionKey[] = "WebKitDatabaseVersionKey";
static const char infoTableName[] = "__WebKitDatabaseInfoTable__";

static String formatErrorMessage(const char* message, int sqliteErrorCode, const char* sqliteErrorMessage)
{
    return String::format("%s (%d %s)", message, sqliteErrorCode, sqliteErrorMessage);
}

static bool retrieveTextResultFromDatabase(SQLiteDatabase& db, const String& query, String& resultString)
{
    SQLiteStatement statement(db, query);
    int result = statement.prepare();

    if (result != SQLResultOk) {
        WTF_LOG_ERROR("Error (%i) preparing statement to read text result from database (%s)", result, query.ascii().data());
        return false;
    }

    result = statement.step();
    if (result == SQLResultRow) {
        resultString = statement.getColumnText(0);
        return true;
    }
    if (result == SQLResultDone) {
        resultString = String();
        return true;
    }

    WTF_LOG_ERROR("Error (%i) reading text result from database (%s)", result, query.ascii().data());
    return false;
}

static bool setTextValueInDatabase(SQLiteDatabase& db, const String& query, const String& value)
{
    SQLiteStatement statement(db, query);
    int result = statement.prepare();

    if (result != SQLResultOk) {
        WTF_LOG_ERROR("Failed to prepare statement to set value in database (%s)", query.ascii().data());
        return false;
    }

    statement.bindText(1, value);

    result = statement.step();
    if (result != SQLResultDone) {
        WTF_LOG_ERROR("Failed to step statement to set value in database (%s)", query.ascii().data());
        return false;
    }

    return true;
}

// FIXME: move all guid-related functions to a DatabaseVersionTracker class.
static Mutex& guidMutex()
{
    AtomicallyInitializedStatic(Mutex&, mutex = *new Mutex);
    return mutex;
}

typedef HashMap<DatabaseGuid, String> GuidVersionMap;
static GuidVersionMap& guidToVersionMap()
{
    // Ensure the the mutex is locked.
    ASSERT(!guidMutex().tryLock());
    DEFINE_STATIC_LOCAL(GuidVersionMap, map, ());
    return map;
}

// NOTE: Caller must lock guidMutex().
static inline void updateGuidVersionMap(DatabaseGuid guid, String newVersion)
{
    // Ensure the the mutex is locked.
    ASSERT(!guidMutex().tryLock());

    // Note: It is not safe to put an empty string into the guidToVersionMap() map.
    // That's because the map is cross-thread, but empty strings are per-thread.
    // The copy() function makes a version of the string you can use on the current
    // thread, but we need a string we can keep in a cross-thread data structure.
    // FIXME: This is a quite-awkward restriction to have to program with.

    // Map null string to empty string (see comment above).
    guidToVersionMap().set(guid, newVersion.isEmpty() ? String() : newVersion.isolatedCopy());
}

typedef HashMap<DatabaseGuid, HashSet<DatabaseBackendBase*>*> GuidDatabaseMap;
static GuidDatabaseMap& guidToDatabaseMap()
{
    // Ensure the the mutex is locked.
    ASSERT(!guidMutex().tryLock());
    DEFINE_STATIC_LOCAL(GuidDatabaseMap, map, ());
    return map;
}

static DatabaseGuid guidForOriginAndName(const String& origin, const String& name)
{
    // Ensure the the mutex is locked.
    ASSERT(!guidMutex().tryLock());

    String stringID = origin + "/" + name;

    typedef HashMap<String, int> IDGuidMap;
    DEFINE_STATIC_LOCAL(IDGuidMap, stringIdentifierToGUIDMap, ());
    DatabaseGuid guid = stringIdentifierToGUIDMap.get(stringID);
    if (!guid) {
        static int currentNewGUID = 1;
        guid = currentNewGUID++;
        stringIdentifierToGUIDMap.set(stringID, guid);
    }

    return guid;
}

// static
const char* DatabaseBackendBase::databaseInfoTableName()
{
    return infoTableName;
}

DatabaseBackendBase::DatabaseBackendBase(DatabaseContext* databaseContext, const String& name,
    const String& expectedVersion, const String& displayName, unsigned long estimatedSize, DatabaseType databaseType)
    : m_databaseContext(databaseContext)
    , m_name(name.isolatedCopy())
    , m_expectedVersion(expectedVersion.isolatedCopy())
    , m_displayName(displayName.isolatedCopy())
    , m_estimatedSize(estimatedSize)
    , m_guid(0)
    , m_opened(false)
    , m_new(false)
    , m_isSyncDatabase(databaseType == DatabaseType::Sync)
{
    m_contextThreadSecurityOrigin = m_databaseContext->securityOrigin()->isolatedCopy();

    m_databaseAuthorizer = DatabaseAuthorizer::create(infoTableName);

    if (m_name.isNull())
        m_name = "";

    {
        MutexLocker locker(guidMutex());
        m_guid = guidForOriginAndName(securityOrigin()->toString(), name);
        HashSet<DatabaseBackendBase*>* hashSet = guidToDatabaseMap().get(m_guid);
        if (!hashSet) {
            hashSet = new HashSet<DatabaseBackendBase*>;
            guidToDatabaseMap().set(m_guid, hashSet);
        }

        hashSet->add(this);
    }

    m_filename = DatabaseManager::manager().fullPathForDatabase(securityOrigin(), m_name);
}

DatabaseBackendBase::~DatabaseBackendBase()
{
    // SQLite is "multi-thread safe", but each database handle can only be used
    // on a single thread at a time.
    //
    // For DatabaseBackend, we open the SQLite database on the DatabaseThread,
    // and hence we should also close it on that same thread. This means that the
    // SQLite database need to be closed by another mechanism (see
    // DatabaseContext::stopDatabases()). By the time we get here, the SQLite
    // database should have already been closed.

    ASSERT(!m_opened);
}

void DatabaseBackendBase::trace(Visitor* visitor)
{
    visitor->trace(m_databaseContext);
    visitor->trace(m_sqliteDatabase);
    visitor->trace(m_databaseAuthorizer);
}

void DatabaseBackendBase::closeDatabase()
{
    if (!m_opened)
        return;

    m_sqliteDatabase.close();
    m_opened = false;
    databaseContext()->didCloseDatabase(*this);
    // See comment at the top this file regarding calling removeOpenDatabase().
    DatabaseTracker::tracker().removeOpenDatabase(this);
    {
        MutexLocker locker(guidMutex());

        HashSet<DatabaseBackendBase*>* hashSet = guidToDatabaseMap().get(m_guid);
        ASSERT(hashSet);
        ASSERT(hashSet->contains(this));
        hashSet->remove(this);
        if (hashSet->isEmpty()) {
            guidToDatabaseMap().remove(m_guid);
            delete hashSet;
            guidToVersionMap().remove(m_guid);
        }
    }
}

String DatabaseBackendBase::version() const
{
    // Note: In multi-process browsers the cached value may be accurate, but we cannot read the
    // actual version from the database without potentially inducing a deadlock.
    // FIXME: Add an async version getter to the DatabaseAPI.
    return getCachedVersion();
}

class DoneCreatingDatabaseOnExitCaller {
public:
    DoneCreatingDatabaseOnExitCaller(DatabaseBackendBase* database)
        : m_database(database)
        , m_openSucceeded(false)
    {
    }
    ~DoneCreatingDatabaseOnExitCaller()
    {
        if (!m_openSucceeded)
            DatabaseTracker::tracker().failedToOpenDatabase(m_database);
    }

    void setOpenSucceeded() { m_openSucceeded = true; }

private:
    DatabaseBackendBase* m_database;
    bool m_openSucceeded;
};

bool DatabaseBackendBase::performOpenAndVerify(bool shouldSetVersionInNewDatabase, DatabaseError& error, String& errorMessage)
{
    DoneCreatingDatabaseOnExitCaller onExitCaller(this);
    ASSERT(errorMessage.isEmpty());
    ASSERT(error == DatabaseError::None); // Better not have any errors already.
    error = DatabaseError::InvalidDatabaseState; // Presumed failure. We'll clear it if we succeed below.

    const int maxSqliteBusyWaitTime = 30000;

    if (!m_sqliteDatabase.open(m_filename, true)) {
        reportOpenDatabaseResult(1, InvalidStateError, m_sqliteDatabase.lastError());
        errorMessage = formatErrorMessage("unable to open database", m_sqliteDatabase.lastError(), m_sqliteDatabase.lastErrorMsg());
        return false;
    }
    if (!m_sqliteDatabase.turnOnIncrementalAutoVacuum())
        WTF_LOG_ERROR("Unable to turn on incremental auto-vacuum (%d %s)", m_sqliteDatabase.lastError(), m_sqliteDatabase.lastErrorMsg());

    m_sqliteDatabase.setBusyTimeout(maxSqliteBusyWaitTime);

    String currentVersion;
    {
        MutexLocker locker(guidMutex());

        GuidVersionMap::iterator entry = guidToVersionMap().find(m_guid);
        if (entry != guidToVersionMap().end()) {
            // Map null string to empty string (see updateGuidVersionMap()).
            currentVersion = entry->value.isNull() ? emptyString() : entry->value.isolatedCopy();
            WTF_LOG(StorageAPI, "Current cached version for guid %i is %s", m_guid, currentVersion.ascii().data());

            // Note: In multi-process browsers the cached value may be inaccurate, but
            // we cannot read the actual version from the database without potentially
            // inducing a form of deadlock, a busytimeout error when trying to
            // access the database. So we'll use the cached value if we're unable to read
            // the value from the database file without waiting.
            // FIXME: Add an async openDatabase method to the DatabaseAPI.
            const int noSqliteBusyWaitTime = 0;
            m_sqliteDatabase.setBusyTimeout(noSqliteBusyWaitTime);
            String versionFromDatabase;
            if (getVersionFromDatabase(versionFromDatabase, false)) {
                currentVersion = versionFromDatabase;
                updateGuidVersionMap(m_guid, currentVersion);
            }
            m_sqliteDatabase.setBusyTimeout(maxSqliteBusyWaitTime);
        } else {
            WTF_LOG(StorageAPI, "No cached version for guid %i", m_guid);

            SQLiteTransaction transaction(m_sqliteDatabase);
            transaction.begin();
            if (!transaction.inProgress()) {
                reportOpenDatabaseResult(2, InvalidStateError, m_sqliteDatabase.lastError());
                errorMessage = formatErrorMessage("unable to open database, failed to start transaction", m_sqliteDatabase.lastError(), m_sqliteDatabase.lastErrorMsg());
                m_sqliteDatabase.close();
                return false;
            }

            String tableName(infoTableName);
            if (!m_sqliteDatabase.tableExists(tableName)) {
                m_new = true;

                if (!m_sqliteDatabase.executeCommand("CREATE TABLE " + tableName + " (key TEXT NOT NULL ON CONFLICT FAIL UNIQUE ON CONFLICT REPLACE,value TEXT NOT NULL ON CONFLICT FAIL);")) {
                    reportOpenDatabaseResult(3, InvalidStateError, m_sqliteDatabase.lastError());
                    errorMessage = formatErrorMessage("unable to open database, failed to create 'info' table", m_sqliteDatabase.lastError(), m_sqliteDatabase.lastErrorMsg());
                    transaction.rollback();
                    m_sqliteDatabase.close();
                    return false;
                }
            } else if (!getVersionFromDatabase(currentVersion, false)) {
                reportOpenDatabaseResult(4, InvalidStateError, m_sqliteDatabase.lastError());
                errorMessage = formatErrorMessage("unable to open database, failed to read current version", m_sqliteDatabase.lastError(), m_sqliteDatabase.lastErrorMsg());
                transaction.rollback();
                m_sqliteDatabase.close();
                return false;
            }

            if (currentVersion.length()) {
                WTF_LOG(StorageAPI, "Retrieved current version %s from database %s", currentVersion.ascii().data(), databaseDebugName().ascii().data());
            } else if (!m_new || shouldSetVersionInNewDatabase) {
                WTF_LOG(StorageAPI, "Setting version %s in database %s that was just created", m_expectedVersion.ascii().data(), databaseDebugName().ascii().data());
                if (!setVersionInDatabase(m_expectedVersion, false)) {
                    reportOpenDatabaseResult(5, InvalidStateError, m_sqliteDatabase.lastError());
                    errorMessage = formatErrorMessage("unable to open database, failed to write current version", m_sqliteDatabase.lastError(), m_sqliteDatabase.lastErrorMsg());
                    transaction.rollback();
                    m_sqliteDatabase.close();
                    return false;
                }
                currentVersion = m_expectedVersion;
            }
            updateGuidVersionMap(m_guid, currentVersion);
            transaction.commit();
        }
    }

    if (currentVersion.isNull()) {
        WTF_LOG(StorageAPI, "Database %s does not have its version set", databaseDebugName().ascii().data());
        currentVersion = "";
    }

    // If the expected version isn't the empty string, ensure that the current database version we have matches that version. Otherwise, set an exception.
    // If the expected version is the empty string, then we always return with whatever version of the database we have.
    if ((!m_new || shouldSetVersionInNewDatabase) && m_expectedVersion.length() && m_expectedVersion != currentVersion) {
        reportOpenDatabaseResult(6, InvalidStateError, 0);
        errorMessage = "unable to open database, version mismatch, '" + m_expectedVersion + "' does not match the currentVersion of '" + currentVersion + "'";
        m_sqliteDatabase.close();
        return false;
    }

    ASSERT(m_databaseAuthorizer);
    m_sqliteDatabase.setAuthorizer(m_databaseAuthorizer.get());

    databaseContext()->didOpenDatabase(*this);
    // See comment at the top this file regarding calling addOpenDatabase().
    DatabaseTracker::tracker().addOpenDatabase(this);
    m_opened = true;

    // Declare success:
    error = DatabaseError::None; // Clear the presumed error from above.
    onExitCaller.setOpenSucceeded();

    if (m_new && !shouldSetVersionInNewDatabase)
        m_expectedVersion = ""; // The caller provided a creationCallback which will set the expected version.

    reportOpenDatabaseResult(0, -1, 0); // OK
    return true;
}

SecurityOrigin* DatabaseBackendBase::securityOrigin() const
{
    return m_contextThreadSecurityOrigin.get();
}

String DatabaseBackendBase::stringIdentifier() const
{
    // Return a deep copy for ref counting thread safety
    return m_name.isolatedCopy();
}

String DatabaseBackendBase::displayName() const
{
    // Return a deep copy for ref counting thread safety
    return m_displayName.isolatedCopy();
}

unsigned long DatabaseBackendBase::estimatedSize() const
{
    return m_estimatedSize;
}

String DatabaseBackendBase::fileName() const
{
    // Return a deep copy for ref counting thread safety
    return m_filename.isolatedCopy();
}

bool DatabaseBackendBase::getVersionFromDatabase(String& version, bool shouldCacheVersion)
{
    String query(String("SELECT value FROM ") + infoTableName +  " WHERE key = '" + versionKey + "';");

    m_databaseAuthorizer->disable();

    bool result = retrieveTextResultFromDatabase(m_sqliteDatabase, query, version);
    if (result) {
        if (shouldCacheVersion)
            setCachedVersion(version);
    } else
        WTF_LOG_ERROR("Failed to retrieve version from database %s", databaseDebugName().ascii().data());

    m_databaseAuthorizer->enable();

    return result;
}

bool DatabaseBackendBase::setVersionInDatabase(const String& version, bool shouldCacheVersion)
{
    // The INSERT will replace an existing entry for the database with the new version number, due to the UNIQUE ON CONFLICT REPLACE
    // clause in the CREATE statement (see Database::performOpenAndVerify()).
    String query(String("INSERT INTO ") + infoTableName +  " (key, value) VALUES ('" + versionKey + "', ?);");

    m_databaseAuthorizer->disable();

    bool result = setTextValueInDatabase(m_sqliteDatabase, query, version);
    if (result) {
        if (shouldCacheVersion)
            setCachedVersion(version);
    } else
        WTF_LOG_ERROR("Failed to set version %s in database (%s)", version.ascii().data(), query.ascii().data());

    m_databaseAuthorizer->enable();

    return result;
}

void DatabaseBackendBase::setExpectedVersion(const String& version)
{
    m_expectedVersion = version.isolatedCopy();
}

String DatabaseBackendBase::getCachedVersion() const
{
    MutexLocker locker(guidMutex());
    return guidToVersionMap().get(m_guid).isolatedCopy();
}

void DatabaseBackendBase::setCachedVersion(const String& actualVersion)
{
    // Update the in memory database version map.
    MutexLocker locker(guidMutex());
    updateGuidVersionMap(m_guid, actualVersion);
}

bool DatabaseBackendBase::getActualVersionForTransaction(String &actualVersion)
{
    ASSERT(m_sqliteDatabase.transactionInProgress());
    // Note: In multi-process browsers the cached value may be inaccurate.
    // So we retrieve the value from the database and update the cached value here.
    return getVersionFromDatabase(actualVersion, true);
}

void DatabaseBackendBase::disableAuthorizer()
{
    ASSERT(m_databaseAuthorizer);
    m_databaseAuthorizer->disable();
}

void DatabaseBackendBase::enableAuthorizer()
{
    ASSERT(m_databaseAuthorizer);
    m_databaseAuthorizer->enable();
}

void DatabaseBackendBase::setAuthorizerPermissions(int permissions)
{
    ASSERT(m_databaseAuthorizer);
    m_databaseAuthorizer->setPermissions(permissions);
}

bool DatabaseBackendBase::lastActionChangedDatabase()
{
    ASSERT(m_databaseAuthorizer);
    return m_databaseAuthorizer->lastActionChangedDatabase();
}

bool DatabaseBackendBase::lastActionWasInsert()
{
    ASSERT(m_databaseAuthorizer);
    return m_databaseAuthorizer->lastActionWasInsert();
}

void DatabaseBackendBase::resetDeletes()
{
    ASSERT(m_databaseAuthorizer);
    m_databaseAuthorizer->resetDeletes();
}

bool DatabaseBackendBase::hadDeletes()
{
    ASSERT(m_databaseAuthorizer);
    return m_databaseAuthorizer->hadDeletes();
}

void DatabaseBackendBase::resetAuthorizer()
{
    if (m_databaseAuthorizer)
        m_databaseAuthorizer->reset();
}

unsigned long long DatabaseBackendBase::maximumSize() const
{
    return DatabaseTracker::tracker().getMaxSizeForDatabase(this);
}

void DatabaseBackendBase::incrementalVacuumIfNeeded()
{
    int64_t freeSpaceSize = m_sqliteDatabase.freeSpaceSize();
    int64_t totalSize = m_sqliteDatabase.totalSize();
    if (totalSize <= 10 * freeSpaceSize) {
        int result = m_sqliteDatabase.runIncrementalVacuumCommand();
        reportVacuumDatabaseResult(result);
        if (result != SQLResultOk)
            logErrorMessage(formatErrorMessage("error vacuuming database", result, m_sqliteDatabase.lastErrorMsg()));
    }
}

void DatabaseBackendBase::interrupt()
{
    m_sqliteDatabase.interrupt();
}

bool DatabaseBackendBase::isInterrupted()
{
    MutexLocker locker(m_sqliteDatabase.databaseMutex());
    return m_sqliteDatabase.isInterrupted();
}

// These are used to generate histograms of errors seen with websql.
// See about:histograms in chromium.
void DatabaseBackendBase::reportOpenDatabaseResult(int errorSite, int webSqlErrorCode, int sqliteErrorCode)
{
    if (blink::Platform::current()->databaseObserver()) {
        blink::Platform::current()->databaseObserver()->reportOpenDatabaseResult(
            createDatabaseIdentifierFromSecurityOrigin(securityOrigin()),
            stringIdentifier(), isSyncDatabase(),
            errorSite, webSqlErrorCode, sqliteErrorCode);
    }
}

void DatabaseBackendBase::reportChangeVersionResult(int errorSite, int webSqlErrorCode, int sqliteErrorCode)
{
    if (blink::Platform::current()->databaseObserver()) {
        blink::Platform::current()->databaseObserver()->reportChangeVersionResult(
            createDatabaseIdentifierFromSecurityOrigin(securityOrigin()),
            stringIdentifier(), isSyncDatabase(),
            errorSite, webSqlErrorCode, sqliteErrorCode);
    }
}

void DatabaseBackendBase::reportStartTransactionResult(int errorSite, int webSqlErrorCode, int sqliteErrorCode)
{
    if (blink::Platform::current()->databaseObserver()) {
        blink::Platform::current()->databaseObserver()->reportStartTransactionResult(
            createDatabaseIdentifierFromSecurityOrigin(securityOrigin()),
            stringIdentifier(), isSyncDatabase(),
            errorSite, webSqlErrorCode, sqliteErrorCode);
    }
}

void DatabaseBackendBase::reportCommitTransactionResult(int errorSite, int webSqlErrorCode, int sqliteErrorCode)
{
    if (blink::Platform::current()->databaseObserver()) {
        blink::Platform::current()->databaseObserver()->reportCommitTransactionResult(
            createDatabaseIdentifierFromSecurityOrigin(securityOrigin()),
            stringIdentifier(), isSyncDatabase(),
            errorSite, webSqlErrorCode, sqliteErrorCode);
    }
}

void DatabaseBackendBase::reportExecuteStatementResult(int errorSite, int webSqlErrorCode, int sqliteErrorCode)
{
    if (blink::Platform::current()->databaseObserver()) {
        blink::Platform::current()->databaseObserver()->reportExecuteStatementResult(
            createDatabaseIdentifierFromSecurityOrigin(securityOrigin()),
            stringIdentifier(), isSyncDatabase(),
            errorSite, webSqlErrorCode, sqliteErrorCode);
    }
}

void DatabaseBackendBase::reportVacuumDatabaseResult(int sqliteErrorCode)
{
    if (blink::Platform::current()->databaseObserver()) {
        blink::Platform::current()->databaseObserver()->reportVacuumDatabaseResult(
            createDatabaseIdentifierFromSecurityOrigin(securityOrigin()),
            stringIdentifier(), isSyncDatabase(), sqliteErrorCode);
    }
}

void DatabaseBackendBase::logErrorMessage(const String& message)
{
    executionContext()->addConsoleMessage(StorageMessageSource, ErrorMessageLevel, message);
}

ExecutionContext* DatabaseBackendBase::executionContext() const
{
    return databaseContext()->executionContext();
}

} // namespace WebCore