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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: sw=2 ts=2 et lcs=trail\:.,tab\:>~ :
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozStorageAsyncStatementExecution_h
#define mozStorageAsyncStatementExecution_h
#include "nscore.h"
#include "nsTArray.h"
#include "nsAutoPtr.h"
#include "mozilla/Mutex.h"
#include "mozilla/TimeStamp.h"
#include "mozilla/Attributes.h"
#include "nsIRunnable.h"
#include "SQLiteMutex.h"
#include "mozIStoragePendingStatement.h"
#include "mozIStorageStatementCallback.h"
#include "mozStorageHelper.h"
struct sqlite3_stmt;
namespace mozilla {
namespace storage {
class Connection;
class ResultSet;
class StatementData;
class AsyncExecuteStatements final : public nsIRunnable
, public mozIStoragePendingStatement
{
public:
NS_DECL_THREADSAFE_ISUPPORTS
NS_DECL_NSIRUNNABLE
NS_DECL_MOZISTORAGEPENDINGSTATEMENT
/**
* Describes the state of execution.
*/
enum ExecutionState {
PENDING = -1,
COMPLETED = mozIStorageStatementCallback::REASON_FINISHED,
CANCELED = mozIStorageStatementCallback::REASON_CANCELED,
ERROR = mozIStorageStatementCallback::REASON_ERROR
};
typedef nsTArray<StatementData> StatementDataArray;
/**
* Executes a statement in the background, and passes results back to the
* caller.
*
* @param aStatements
* The statements to execute and possibly bind in the background.
* Ownership is transfered from the caller.
* @param aConnection
* The connection that created the statements to execute.
* @param aNativeConnection
* The native Sqlite connection that created the statements to execute.
* @param aCallback
* The callback that is notified of results, completion, and errors.
* @param _stmt
* The handle to control the execution of the statements.
*/
static nsresult execute(StatementDataArray &aStatements,
Connection *aConnection,
sqlite3 *aNativeConnection,
mozIStorageStatementCallback *aCallback,
mozIStoragePendingStatement **_stmt);
/**
* Indicates when events on the calling thread should run or not. Certain
* events posted back to the calling thread should call this see if they
* should run or not.
*
* @pre mMutex is not held
*
* @returns true if the event should notify still, false otherwise.
*/
bool shouldNotify();
private:
AsyncExecuteStatements(StatementDataArray &aStatements,
Connection *aConnection,
sqlite3 *aNativeConnection,
mozIStorageStatementCallback *aCallback);
~AsyncExecuteStatements();
/**
* Binds and then executes a given statement until completion, an error
* occurs, or we are canceled. If aLastStatement is true, we should set
* mState accordingly.
*
* @pre mMutex is not held
*
* @param aData
* The StatementData to bind, execute, and then process.
* @param aLastStatement
* Indicates if this is the last statement or not. If it is, we have
* to set the proper state.
* @returns true if we should continue to process statements, false otherwise.
*/
bool bindExecuteAndProcessStatement(StatementData &aData,
bool aLastStatement);
/**
* Executes a given statement until completion, an error occurs, or we are
* canceled. If aLastStatement is true, we should set mState accordingly.
*
* @pre mMutex is not held
*
* @param aStatement
* The statement to execute and then process.
* @param aLastStatement
* Indicates if this is the last statement or not. If it is, we have
* to set the proper state.
* @returns true if we should continue to process statements, false otherwise.
*/
bool executeAndProcessStatement(sqlite3_stmt *aStatement,
bool aLastStatement);
/**
* Executes a statement to completion, properly handling any error conditions.
*
* @pre mMutex is not held
*
* @param aStatement
* The statement to execute to completion.
* @returns true if results were obtained, false otherwise.
*/
bool executeStatement(sqlite3_stmt *aStatement);
/**
* Builds a result set up with a row from a given statement. If we meet the
* right criteria, go ahead and notify about this results too.
*
* @pre mMutex is not held
*
* @param aStatement
* The statement to get the row data from.
*/
nsresult buildAndNotifyResults(sqlite3_stmt *aStatement);
/**
* Notifies callback about completion, and does any necessary cleanup.
*
* @pre mMutex is not held
*/
nsresult notifyComplete();
/**
* Notifies callback about an error.
*
* @pre mMutex is not held
* @pre mDBMutex is not held
*
* @param aErrorCode
* The error code defined in mozIStorageError for the error.
* @param aMessage
* The error string, if any.
* @param aError
* The error object to notify the caller with.
*/
nsresult notifyError(int32_t aErrorCode, const char *aMessage);
nsresult notifyError(mozIStorageError *aError);
/**
* Notifies the callback about a result set.
*
* @pre mMutex is not held
*/
nsresult notifyResults();
/**
* Tests whether the current statements should be wrapped in an explicit
* transaction.
*
* @return true if an explicit transaction is needed, false otherwise.
*/
bool statementsNeedTransaction();
StatementDataArray mStatements;
RefPtr<Connection> mConnection;
sqlite3 *mNativeConnection;
bool mHasTransaction;
mozIStorageStatementCallback *mCallback;
nsCOMPtr<nsIThread> mCallingThread;
RefPtr<ResultSet> mResultSet;
/**
* The maximum amount of time we want to wait between results. Defined by
* MAX_MILLISECONDS_BETWEEN_RESULTS and set at construction.
*/
const TimeDuration mMaxWait;
/**
* The start time since our last set of results.
*/
TimeStamp mIntervalStart;
/**
* Indicates our state of execution.
*/
ExecutionState mState;
/**
* Indicates if we should try to cancel at a cancelation point.
*/
bool mCancelRequested;
/**
* This is the mutex that protects our state from changing between threads.
* This includes the following variables:
* - mCancelRequested is only set on the calling thread while the lock is
* held. It is always read from within the lock on the background thread,
* but not on the calling thread (see shouldNotify for why).
*/
Mutex &mMutex;
/**
* The wrapped SQLite recursive connection mutex. We use it whenever we call
* sqlite3_step and care about having reliable error messages. By taking it
* prior to the call and holding it until the point where we no longer care
* about the error message, the user gets reliable error messages.
*/
SQLiteMutex &mDBMutex;
/**
* The instant at which the request was started.
*
* Used by telemetry.
*/
TimeStamp mRequestStartDate;
};
} // namespace storage
} // namespace mozilla
#endif // mozStorageAsyncStatementExecution_h
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