Source/modules/webdatabase/SQLTransactionBackend.h

/*
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
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 *
 * 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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 *     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
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#ifndef SQLTransactionBackend_h
#define SQLTransactionBackend_h

#include "modules/webdatabase/DatabaseBasicTypes.h"
#include "modules/webdatabase/SQLStatement.h"
#include "modules/webdatabase/SQLTransactionStateMachine.h"
#include "platform/heap/Handle.h"
#include "wtf/Deque.h"
#include "wtf/Forward.h"
#include "wtf/ThreadingPrimitives.h"

namespace blink {

class Database;
class SQLErrorData;
class SQLiteTransaction;
class SQLStatementBackend;
class SQLTransaction;
class SQLTransactionBackend;
class SQLValue;

class SQLTransactionWrapper : public GarbageCollectedFinalized<SQLTransactionWrapper> {
public:
    virtual ~SQLTransactionWrapper() { }
    virtual void trace(Visitor*) { }
    virtual bool performPreflight(SQLTransactionBackend*) = 0;
    virtual bool performPostflight(SQLTransactionBackend*) = 0;
    virtual SQLErrorData* sqlError() const = 0;
    virtual void handleCommitFailedAfterPostflight(SQLTransactionBackend*) = 0;
};

class SQLTransactionBackend final : public GarbageCollectedFinalized<SQLTransactionBackend>, public SQLTransactionStateMachine<SQLTransactionBackend> {
public:
    static SQLTransactionBackend* create(Database*, SQLTransaction*, SQLTransactionWrapper*, bool readOnly);

    virtual ~SQLTransactionBackend();
    void trace(Visitor*);

    void lockAcquired();
    void performNextStep();

    Database* database() { return m_database.get(); }
    bool isReadOnly() { return m_readOnly; }
    void notifyDatabaseThreadIsShuttingDown();

    // APIs called from the frontend published:
    void requestTransitToState(SQLTransactionState);
    SQLErrorData* transactionError();
    SQLStatement* currentStatement();
    void setShouldRetryCurrentStatement(bool);
    void executeSQL(SQLStatement*, const String& statement, const Vector<SQLValue>& arguments, int permissions);

private:
    SQLTransactionBackend(Database*, SQLTransaction*, SQLTransactionWrapper*, bool readOnly);

    void doCleanup();

    void enqueueStatementBackend(SQLStatementBackend*);

    // State Machine functions:
    virtual StateFunction stateFunctionFor(SQLTransactionState) override;
    void computeNextStateAndCleanupIfNeeded();

    // State functions:
    SQLTransactionState acquireLock();
    SQLTransactionState openTransactionAndPreflight();
    SQLTransactionState runStatements();
    SQLTransactionState postflightAndCommit();
    SQLTransactionState cleanupAndTerminate();
    SQLTransactionState cleanupAfterTransactionErrorCallback();

    SQLTransactionState unreachableState();
    SQLTransactionState sendToFrontendState();

    SQLTransactionState nextStateForCurrentStatementError();
    SQLTransactionState nextStateForTransactionError();
    SQLTransactionState runCurrentStatementAndGetNextState();

    void getNextStatement();

    Member<SQLTransaction> m_frontend;
    Member<SQLStatementBackend> m_currentStatementBackend;

    Member<Database> m_database;
    Member<SQLTransactionWrapper> m_wrapper;
    OwnPtr<SQLErrorData> m_transactionError;

    bool m_hasCallback;
    bool m_hasSuccessCallback;
    bool m_hasErrorCallback;
    bool m_shouldRetryCurrentStatement;
    bool m_modifiedDatabase;
    bool m_lockAcquired;
    bool m_readOnly;
    bool m_hasVersionMismatch;

    Mutex m_statementMutex;
    HeapDeque<Member<SQLStatementBackend> > m_statementQueue;

    OwnPtr<SQLiteTransaction> m_sqliteTransaction;
};

} // namespace blink

#endif // SQLTransactionBackend_h