Source/WebCore/Modules/webdatabase/AbstractDatabase.cpp - platform/external/chromium_org/third_party/WebKit - Git at Google

 /*
  * Copyright (C) 2011 Google 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 "AbstractDatabase.h"

 #if ENABLE(SQL_DATABASE)

 #include "DatabaseAuthorizer.h"
 #include "DatabaseContext.h"
 #include "DatabaseTracker.h"
 #include "ExceptionCode.h"
 #include "Logging.h"
 #include "SQLiteStatement.h"
 #include "SQLiteTransaction.h"
 #include "ScriptCallStack.h"
 #include "ScriptExecutionContext.h"
 #include "SecurityOrigin.h"
 #include <wtf/HashMap.h>
 #include <wtf/HashSet.h>
 #include <wtf/PassRefPtr.h>
 #include <wtf/RefPtr.h>
 #include <wtf/StdLibExtras.h>
 #include <wtf/text/CString.h>
 #include <wtf/text/StringHash.h>

 #if PLATFORM(CHROMIUM)
 #include "DatabaseObserver.h" // For error reporting.
 #endif

 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) {
         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;
     }

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

 static int 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, ());
     int guid = stringIdentifierToGUIDMap.get(stringID);
     if (!guid) {
         static int currentNewGUID = 1;
         guid = currentNewGUID++;
         stringIdentifierToGUIDMap.set(stringID, guid);
     }

     return guid;
 }

 static bool isDatabaseAvailable = true;

 bool AbstractDatabase::isAvailable()
 {
     return isDatabaseAvailable;
 }

 void AbstractDatabase::setIsAvailable(bool available)
 {
     isDatabaseAvailable = available;
 }

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

 AbstractDatabase::AbstractDatabase(ScriptExecutionContext* context, const String& name, const String& expectedVersion,
                                    const String& displayName, unsigned long estimatedSize, DatabaseType databaseType)
     : m_scriptExecutionContext(context)
     , m_databaseContext(DatabaseContext::from(context))
     , 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 == SyncDatabase)
 {
     ASSERT(context->isContextThread());
     m_contextThreadSecurityOrigin = m_scriptExecutionContext->securityOrigin();

     m_databaseAuthorizer = DatabaseAuthorizer::create(infoTableName);

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

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

         hashSet->add(this);
     }

     m_filename = DatabaseTracker::tracker().fullPathForDatabase(securityOrigin(), m_name);
     DatabaseTracker::tracker().addOpenDatabase(this);
 }

 AbstractDatabase::~AbstractDatabase()
 {
     ASSERT(!m_opened);
 }

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

     m_sqliteDatabase.close();
     m_opened = false;
     {
         MutexLocker locker(guidMutex());

         HashSet<AbstractDatabase*>* 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 AbstractDatabase::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();
 }

 bool AbstractDatabase::performOpenAndVerify(bool shouldSetVersionInNewDatabase, ExceptionCode& ec, String& errorMessage)
 {
     ASSERT(errorMessage.isEmpty());

     const int maxSqliteBusyWaitTime = 30000;

     if (!m_sqliteDatabase.open(m_filename, true)) {
         reportOpenDatabaseResult(1, INVALID_STATE_ERR, m_sqliteDatabase.lastError());
         errorMessage = formatErrorMessage("unable to open database", m_sqliteDatabase.lastError(), m_sqliteDatabase.lastErrorMsg());
         ec = INVALID_STATE_ERR;
         return false;
     }
     if (!m_sqliteDatabase.turnOnIncrementalAutoVacuum())
         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();
             LOG(StorageAPI, "Current cached version for guid %i is %s", m_guid, currentVersion.ascii().data());

 #if PLATFORM(CHROMIUM)
             // 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);
 #endif
         } else {
             LOG(StorageAPI, "No cached version for guid %i", m_guid);

             SQLiteTransaction transaction(m_sqliteDatabase);
             transaction.begin();
             if (!transaction.inProgress()) {
                 reportOpenDatabaseResult(2, INVALID_STATE_ERR, m_sqliteDatabase.lastError());
                 errorMessage = formatErrorMessage("unable to open database, failed to start transaction", m_sqliteDatabase.lastError(), m_sqliteDatabase.lastErrorMsg());
                 ec = INVALID_STATE_ERR;
                 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, INVALID_STATE_ERR, m_sqliteDatabase.lastError());
                     errorMessage = formatErrorMessage("unable to open database, failed to create 'info' table", m_sqliteDatabase.lastError(), m_sqliteDatabase.lastErrorMsg());
                     ec = INVALID_STATE_ERR;
                     transaction.rollback();
                     m_sqliteDatabase.close();
                     return false;
                 }
             } else if (!getVersionFromDatabase(currentVersion, false)) {
                 reportOpenDatabaseResult(4, INVALID_STATE_ERR, m_sqliteDatabase.lastError());
                 errorMessage = formatErrorMessage("unable to open database, failed to read current version", m_sqliteDatabase.lastError(), m_sqliteDatabase.lastErrorMsg());
                 ec = INVALID_STATE_ERR;
                 transaction.rollback();
                 m_sqliteDatabase.close();
                 return false;
             }

             if (currentVersion.length()) {
                 LOG(StorageAPI, "Retrieved current version %s from database %s", currentVersion.ascii().data(), databaseDebugName().ascii().data());
             } else if (!m_new || shouldSetVersionInNewDatabase) {
                 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, INVALID_STATE_ERR, m_sqliteDatabase.lastError());
                     errorMessage = formatErrorMessage("unable to open database, failed to write current version", m_sqliteDatabase.lastError(), m_sqliteDatabase.lastErrorMsg());
                     ec = INVALID_STATE_ERR;
                     transaction.rollback();
                     m_sqliteDatabase.close();
                     return false;
                 }
                 currentVersion = m_expectedVersion;
             }
             updateGuidVersionMap(m_guid, currentVersion);
             transaction.commit();
         }
     }

     if (currentVersion.isNull()) {
         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, INVALID_STATE_ERR, 0);
         errorMessage = "unable to open database, version mismatch, '" + m_expectedVersion + "' does not match the currentVersion of '" + currentVersion + "'";
         ec = INVALID_STATE_ERR;
         m_sqliteDatabase.close();
         return false;
     }

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

     m_opened = true;

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

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

 ScriptExecutionContext* AbstractDatabase::scriptExecutionContext() const
 {
     return m_scriptExecutionContext.get();
 }

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

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

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

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

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

 bool AbstractDatabase::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
         LOG_ERROR("Failed to retrieve version from database %s", databaseDebugName().ascii().data());

     m_databaseAuthorizer->enable();

     return result;
 }

 bool AbstractDatabase::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
         LOG_ERROR("Failed to set version %s in database (%s)", version.ascii().data(), query.ascii().data());

     m_databaseAuthorizer->enable();

     return result;
 }

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

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

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

 bool AbstractDatabase::getActualVersionForTransaction(String &actualVersion)
 {
     ASSERT(m_sqliteDatabase.transactionInProgress());
 #if PLATFORM(CHROMIUM)
     // 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);
 #else
     actualVersion = getCachedVersion();
     return true;
 #endif
 }

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

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

 void AbstractDatabase::setAuthorizerReadOnly()
 {
     ASSERT(m_databaseAuthorizer);
     m_databaseAuthorizer->setReadOnly();
 }

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

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

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

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

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

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

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

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

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

 void AbstractDatabase::logErrorMessage(const String& message)
 {
     m_scriptExecutionContext->addConsoleMessage(OtherMessageSource, LogMessageType, ErrorMessageLevel, message);
 }

 #if PLATFORM(CHROMIUM)
 // These are used to generate histograms of errors seen with websql.
 // See about:histograms in chromium.
 void AbstractDatabase::reportOpenDatabaseResult(int errorSite, int webSqlErrorCode, int sqliteErrorCode)
 {
     DatabaseObserver::reportOpenDatabaseResult(this, errorSite, webSqlErrorCode, sqliteErrorCode);
 }

 void AbstractDatabase::reportChangeVersionResult(int errorSite, int webSqlErrorCode, int sqliteErrorCode)
 {
     DatabaseObserver::reportChangeVersionResult(this, errorSite, webSqlErrorCode, sqliteErrorCode);
 }

 void AbstractDatabase::reportStartTransactionResult(int errorSite, int webSqlErrorCode, int sqliteErrorCode)
 {
     DatabaseObserver::reportStartTransactionResult(this, errorSite, webSqlErrorCode, sqliteErrorCode);
 }

 void AbstractDatabase::reportCommitTransactionResult(int errorSite, int webSqlErrorCode, int sqliteErrorCode)
 {
     DatabaseObserver::reportCommitTransactionResult(this, errorSite, webSqlErrorCode, sqliteErrorCode);
 }

 void AbstractDatabase::reportExecuteStatementResult(int errorSite, int webSqlErrorCode, int sqliteErrorCode)
 {
     DatabaseObserver::reportExecuteStatementResult(this, errorSite, webSqlErrorCode, sqliteErrorCode);
 }

 void AbstractDatabase::reportVacuumDatabaseResult(int sqliteErrorCode)
 {
     DatabaseObserver::reportVacuumDatabaseResult(this, sqliteErrorCode);
 }

 #else
 void AbstractDatabase::reportOpenDatabaseResult(int, int, int) { }
 void AbstractDatabase::reportChangeVersionResult(int, int, int) { }
 void AbstractDatabase::reportStartTransactionResult(int, int, int) { }
 void AbstractDatabase::reportCommitTransactionResult(int, int, int) { }
 void AbstractDatabase::reportExecuteStatementResult(int, int, int) { }
 void AbstractDatabase::reportVacuumDatabaseResult(int) { }
 #endif // PLATFORM(CHROMIUM)

 } // namespace WebCore

 #endif // ENABLE(SQL_DATABASE)
	/*
	* Copyright (C) 2011 Google 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 "AbstractDatabase.h"

	#if ENABLE(SQL_DATABASE)

	#include "DatabaseAuthorizer.h"
	#include "DatabaseContext.h"
	#include "DatabaseTracker.h"
	#include "ExceptionCode.h"
	#include "Logging.h"
	#include "SQLiteStatement.h"
	#include "SQLiteTransaction.h"
	#include "ScriptCallStack.h"
	#include "ScriptExecutionContext.h"
	#include "SecurityOrigin.h"
	#include <wtf/HashMap.h>
	#include <wtf/HashSet.h>
	#include <wtf/PassRefPtr.h>
	#include <wtf/RefPtr.h>
	#include <wtf/StdLibExtras.h>
	#include <wtf/text/CString.h>
	#include <wtf/text/StringHash.h>

	#if PLATFORM(CHROMIUM)
	#include "DatabaseObserver.h" // For error reporting.
	#endif

	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) {
	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;
	}

	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) {
	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) {
	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<int, 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(int 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<int, HashSet<AbstractDatabase>> GuidDatabaseMap;
	static GuidDatabaseMap& guidToDatabaseMap()
	{
	// Ensure the the mutex is locked.
	ASSERT(!guidMutex().tryLock());
	DEFINE_STATIC_LOCAL(GuidDatabaseMap, map, ());
	return map;
	}

	static int 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, ());
	int guid = stringIdentifierToGUIDMap.get(stringID);
	if (!guid) {
	static int currentNewGUID = 1;
	guid = currentNewGUID++;
	stringIdentifierToGUIDMap.set(stringID, guid);
	}

	return guid;
	}

	static bool isDatabaseAvailable = true;

	bool AbstractDatabase::isAvailable()
	{
	return isDatabaseAvailable;
	}

	void AbstractDatabase::setIsAvailable(bool available)
	{
	isDatabaseAvailable = available;
	}

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

	AbstractDatabase::AbstractDatabase(ScriptExecutionContext* context, const String& name, const String& expectedVersion,
	const String& displayName, unsigned long estimatedSize, DatabaseType databaseType)
	: m_scriptExecutionContext(context)
	, m_databaseContext(DatabaseContext::from(context))
	, 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 == SyncDatabase)
	{
	ASSERT(context->isContextThread());
	m_contextThreadSecurityOrigin = m_scriptExecutionContext->securityOrigin();

	m_databaseAuthorizer = DatabaseAuthorizer::create(infoTableName);

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

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

	hashSet->add(this);
	}

	m_filename = DatabaseTracker::tracker().fullPathForDatabase(securityOrigin(), m_name);
	DatabaseTracker::tracker().addOpenDatabase(this);
	}

	AbstractDatabase::~AbstractDatabase()
	{
	ASSERT(!m_opened);
	}

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

	m_sqliteDatabase.close();
	m_opened = false;
	{
	MutexLocker locker(guidMutex());

	HashSet<AbstractDatabase> 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 AbstractDatabase::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();
	}

	bool AbstractDatabase::performOpenAndVerify(bool shouldSetVersionInNewDatabase, ExceptionCode& ec, String& errorMessage)
	{
	ASSERT(errorMessage.isEmpty());

	const int maxSqliteBusyWaitTime = 30000;

	if (!m_sqliteDatabase.open(m_filename, true)) {
	reportOpenDatabaseResult(1, INVALID_STATE_ERR, m_sqliteDatabase.lastError());
	errorMessage = formatErrorMessage("unable to open database", m_sqliteDatabase.lastError(), m_sqliteDatabase.lastErrorMsg());
	ec = INVALID_STATE_ERR;
	return false;
	}
	if (!m_sqliteDatabase.turnOnIncrementalAutoVacuum())
	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();
	LOG(StorageAPI, "Current cached version for guid %i is %s", m_guid, currentVersion.ascii().data());

	#if PLATFORM(CHROMIUM)
	// 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);
	#endif
	} else {
	LOG(StorageAPI, "No cached version for guid %i", m_guid);

	SQLiteTransaction transaction(m_sqliteDatabase);
	transaction.begin();
	if (!transaction.inProgress()) {
	reportOpenDatabaseResult(2, INVALID_STATE_ERR, m_sqliteDatabase.lastError());
	errorMessage = formatErrorMessage("unable to open database, failed to start transaction", m_sqliteDatabase.lastError(), m_sqliteDatabase.lastErrorMsg());
	ec = INVALID_STATE_ERR;
	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, INVALID_STATE_ERR, m_sqliteDatabase.lastError());
	errorMessage = formatErrorMessage("unable to open database, failed to create 'info' table", m_sqliteDatabase.lastError(), m_sqliteDatabase.lastErrorMsg());
	ec = INVALID_STATE_ERR;
	transaction.rollback();
	m_sqliteDatabase.close();
	return false;
	}
	} else if (!getVersionFromDatabase(currentVersion, false)) {
	reportOpenDatabaseResult(4, INVALID_STATE_ERR, m_sqliteDatabase.lastError());
	errorMessage = formatErrorMessage("unable to open database, failed to read current version", m_sqliteDatabase.lastError(), m_sqliteDatabase.lastErrorMsg());
	ec = INVALID_STATE_ERR;
	transaction.rollback();
	m_sqliteDatabase.close();
	return false;
	}

	if (currentVersion.length()) {
	LOG(StorageAPI, "Retrieved current version %s from database %s", currentVersion.ascii().data(), databaseDebugName().ascii().data());
	} else if (!m_new \|\| shouldSetVersionInNewDatabase) {
	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, INVALID_STATE_ERR, m_sqliteDatabase.lastError());
	errorMessage = formatErrorMessage("unable to open database, failed to write current version", m_sqliteDatabase.lastError(), m_sqliteDatabase.lastErrorMsg());
	ec = INVALID_STATE_ERR;
	transaction.rollback();
	m_sqliteDatabase.close();
	return false;
	}
	currentVersion = m_expectedVersion;
	}
	updateGuidVersionMap(m_guid, currentVersion);
	transaction.commit();
	}
	}

	if (currentVersion.isNull()) {
	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, INVALID_STATE_ERR, 0);
	errorMessage = "unable to open database, version mismatch, '" + m_expectedVersion + "' does not match the currentVersion of '" + currentVersion + "'";
	ec = INVALID_STATE_ERR;
	m_sqliteDatabase.close();
	return false;
	}

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

	m_opened = true;

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

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

	ScriptExecutionContext* AbstractDatabase::scriptExecutionContext() const
	{
	return m_scriptExecutionContext.get();
	}

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

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

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

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

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

	bool AbstractDatabase::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
	LOG_ERROR("Failed to retrieve version from database %s", databaseDebugName().ascii().data());

	m_databaseAuthorizer->enable();

	return result;
	}

	bool AbstractDatabase::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
	LOG_ERROR("Failed to set version %s in database (%s)", version.ascii().data(), query.ascii().data());

	m_databaseAuthorizer->enable();

	return result;
	}

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

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

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

	bool AbstractDatabase::getActualVersionForTransaction(String &actualVersion)
	{
	ASSERT(m_sqliteDatabase.transactionInProgress());
	#if PLATFORM(CHROMIUM)
	// 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);
	#else
	actualVersion = getCachedVersion();
	return true;
	#endif
	}

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

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

	void AbstractDatabase::setAuthorizerReadOnly()
	{
	ASSERT(m_databaseAuthorizer);
	m_databaseAuthorizer->setReadOnly();
	}

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

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

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

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

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

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

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

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

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

	void AbstractDatabase::logErrorMessage(const String& message)
	{
	m_scriptExecutionContext->addConsoleMessage(OtherMessageSource, LogMessageType, ErrorMessageLevel, message);
	}

	#if PLATFORM(CHROMIUM)
	// These are used to generate histograms of errors seen with websql.
	// See about:histograms in chromium.
	void AbstractDatabase::reportOpenDatabaseResult(int errorSite, int webSqlErrorCode, int sqliteErrorCode)
	{
	DatabaseObserver::reportOpenDatabaseResult(this, errorSite, webSqlErrorCode, sqliteErrorCode);
	}

	void AbstractDatabase::reportChangeVersionResult(int errorSite, int webSqlErrorCode, int sqliteErrorCode)
	{
	DatabaseObserver::reportChangeVersionResult(this, errorSite, webSqlErrorCode, sqliteErrorCode);
	}

	void AbstractDatabase::reportStartTransactionResult(int errorSite, int webSqlErrorCode, int sqliteErrorCode)
	{
	DatabaseObserver::reportStartTransactionResult(this, errorSite, webSqlErrorCode, sqliteErrorCode);
	}

	void AbstractDatabase::reportCommitTransactionResult(int errorSite, int webSqlErrorCode, int sqliteErrorCode)
	{
	DatabaseObserver::reportCommitTransactionResult(this, errorSite, webSqlErrorCode, sqliteErrorCode);
	}

	void AbstractDatabase::reportExecuteStatementResult(int errorSite, int webSqlErrorCode, int sqliteErrorCode)
	{
	DatabaseObserver::reportExecuteStatementResult(this, errorSite, webSqlErrorCode, sqliteErrorCode);
	}

	void AbstractDatabase::reportVacuumDatabaseResult(int sqliteErrorCode)
	{
	DatabaseObserver::reportVacuumDatabaseResult(this, sqliteErrorCode);
	}

	#else
	void AbstractDatabase::reportOpenDatabaseResult(int, int, int) { }
	void AbstractDatabase::reportChangeVersionResult(int, int, int) { }
	void AbstractDatabase::reportStartTransactionResult(int, int, int) { }
	void AbstractDatabase::reportCommitTransactionResult(int, int, int) { }
	void AbstractDatabase::reportExecuteStatementResult(int, int, int) { }
	void AbstractDatabase::reportVacuumDatabaseResult(int) { }
	#endif // PLATFORM(CHROMIUM)

	} // namespace WebCore

	#endif // ENABLE(SQL_DATABASE)