poco/Data/include/Poco/Data/SQLChannel.h
Guenter Obiltschnig 97d8c42a4e fixed file headers
2017-02-18 14:29:15 +01:00

220 lines
7.0 KiB
C++

//
// SQLChannel.h
//
// $Id: //poco/Main/Data/include/Poco/Data/SQLChannel.h#4 $
//
// Library: Data
// Package: Logging
// Module: SQLChannel
//
// Definition of the SQLChannel class.
//
// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#ifndef Data_SQLChannel_INCLUDED
#define Data_SQLChannel_INCLUDED
#include "Poco/Data/Data.h"
#include "Poco/Data/Connector.h"
#include "Poco/Data/Session.h"
#include "Poco/Data/Statement.h"
#include "Poco/Data/ArchiveStrategy.h"
#include "Poco/Channel.h"
#include "Poco/Message.h"
#include "Poco/AutoPtr.h"
#include "Poco/String.h"
namespace Poco {
namespace Data {
class Data_API SQLChannel: public Poco::Channel
/// This Channel implements logging to a SQL database.
/// The channel is dependent on the schema. The DDL for
/// table creation (subject to target DDL dialect dependent
/// modifications) is:
///
/// "CREATE TABLE T_POCO_LOG (Source VARCHAR,
/// Name VARCHAR,
/// ProcessId INTEGER,
/// Thread VARCHAR,
/// ThreadId INTEGER,
/// Priority INTEGER,
/// Text VARCHAR,
/// DateTime DATE)"
///
/// The table name is configurable through "table" property.
/// Other than DateTime filed name used for optional time-based archiving purposes, currently the
/// field names are not mandated. However, it is recommended to use names as specified above.
///
/// To provide as non-intrusive operation as possible, the log entries are cached and
/// inserted into the target database asynchronously by default . The blocking, however, will occur
/// before the next entry insertion with default timeout of 1 second. The default settings can be
/// overriden (see async, timeout and throw properties for details).
/// If throw property is false, insertion timeouts are ignored, otherwise a TimeoutException is thrown.
/// To force insertion of every entry, set timeout to 0. This setting, however, introduces
/// a risk of long blocking periods in case of remote server communication delays.
{
public:
SQLChannel();
/// Creates SQLChannel.
SQLChannel(const std::string& connector,
const std::string& connect,
const std::string& name = "-");
/// Creates a SQLChannel with the given connector, connect string, timeout, table and name.
/// The connector must be already registered.
void open();
/// Opens the SQLChannel.
void close();
/// Closes the SQLChannel.
void log(const Message& msg);
/// Sends the message's text to the syslog service.
void setProperty(const std::string& name, const std::string& value);
/// Sets the property with the given value.
///
/// The following properties are supported:
/// * name: The name used to identify the source of log messages.
/// Defaults to "-".
///
/// * target: The target data storage type ("SQLite", "ODBC", ...).
///
/// * connector: The target data storage connector name.
///
/// * connect: The target data storage connection string.
///
/// * table: Destination log table name. Defaults to "T_POCO_LOG".
/// Table must exist in the target database.
///
/// * keep: Max row age for the log table. To disable archiving,
/// set this property to empty string or "forever".
///
/// * archive: Archive table name. Defaults to "T_POCO_LOG_ARCHIVE".
/// Table must exist in the target database. To disable archiving,
/// set this property to empty string.
///
/// * async: Indicates asynchronous execution. When executing asynchronously,
/// messages are sent to the target using asynchronous execution.
/// However, prior to the next message being processed and sent to
/// the target, the previous operation must have been either completed
/// or timed out (see timeout and throw properties for details on
/// how abnormal conditions are handled).
///
/// * timeout: Timeout (ms) to wait for previous log operation completion.
/// Values "0" and "" mean no timeout. Only valid when logging
/// is asynchronous, otherwise ignored.
///
/// * throw: Boolean value indicating whether to throw in case of timeout.
/// Setting this property to false may result in log entries being lost.
/// True values are (case insensitive) "true", "t", "yes", "y".
/// Anything else yields false.
std::string getProperty(const std::string& name) const;
/// Returns the value of the property with the given name.
std::size_t wait();
/// Waits for the completion of the previous operation and returns
/// the result. If channel is in synchronous mode, returns 0 immediately.
static void registerChannel();
/// Registers the channel with the global LoggingFactory.
static const std::string PROP_CONNECT;
static const std::string PROP_CONNECTOR;
static const std::string PROP_NAME;
static const std::string PROP_TABLE;
static const std::string PROP_ARCHIVE_TABLE;
static const std::string PROP_MAX_AGE;
static const std::string PROP_ASYNC;
static const std::string PROP_TIMEOUT;
static const std::string PROP_THROW;
protected:
~SQLChannel();
private:
typedef Poco::SharedPtr<Session> SessionPtr;
typedef Poco::SharedPtr<Statement> StatementPtr;
typedef Poco::Message::Priority Priority;
typedef Poco::SharedPtr<ArchiveStrategy> StrategyPtr;
void initLogStatement();
/// Initializes the log statement.
void initArchiveStatements();
/// Initializes the archive statement.
void logAsync(const Message& msg);
/// Waits for previous operation completion and
/// calls logSync(). If the previous operation times out,
/// and _throw is true, TimeoutException is thrown, otherwise
/// the timeout is ignored and log entry is lost.
void logSync(const Message& msg);
/// Inserts the message in the target database.
bool isTrue(const std::string& value) const;
/// Returns true is value is "true", "t", "yes" or "y".
/// Case insensitive.
std::string _connector;
std::string _connect;
SessionPtr _pSession;
StatementPtr _pLogStatement;
std::string _name;
std::string _table;
int _timeout;
bool _throw;
bool _async;
// members for log entry cache (needed for async mode)
std::string _source;
long _pid;
std::string _thread;
long _tid;
int _priority;
std::string _text;
DateTime _dateTime;
StrategyPtr _pArchiveStrategy;
};
//
// inlines
//
inline std::size_t SQLChannel::wait()
{
if (_async && _pLogStatement)
return _pLogStatement->wait(_timeout);
return 0;
}
inline bool SQLChannel::isTrue(const std::string& value) const
{
return ((0 == icompare(value, "true")) ||
(0 == icompare(value, "t")) ||
(0 == icompare(value, "yes")) ||
(0 == icompare(value, "y")));
}
} } // namespace Poco::Data
#endif // Data_SQLChannel_INCLUDED