79 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			79 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /*
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|  * Copyright (c) 2018 MariaDB Corporation Ab
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|  *
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|  * Use of this software is governed by the Business Source License included
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|  * in the LICENSE.TXT file and at www.mariadb.com/bsl11.
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|  *
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|  * Change Date: 2022-01-01
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|  *
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|  * On the date above, in accordance with the Business Source License, use
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|  * of this software will be governed by version 2 or later of the General
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|  * Public License.
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|  */
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| #pragma once
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| 
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| #include <maxscale/ccdefs.hh>
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| #include <maxscale/filter.hh>
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| 
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| class ExampleFilter;
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| 
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| /*
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|  * Defines session-specific data for this filter. An object of this class is created when a client connects
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|  * and deleted on disconnect. The object is only accessed from one thread because sessions are locked to
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|  * a thread when created.
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|  */
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| class ExampleFilterSession : public maxscale::FilterSession
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| {
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|     // Prevent copy-constructor and assignment operator usage
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|     ExampleFilterSession(const ExampleFilterSession&);
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|     ExampleFilterSession& operator=(const ExampleFilterSession&);
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| 
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| public:
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|     ~ExampleFilterSession();
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| 
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|     // Called when a client session has been closed. Destructor will be called right after.
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|     void close();
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| 
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|     /**
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|      * Called by ExampleFilter::newSession() to create the session.
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|      *
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|      * @param pSession pSession The generic MaxScale session object
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|      * @param pFilter The shared filter object
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|      * @return A new session or NULL on failure
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|      */
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|     static ExampleFilterSession* create(MXS_SESSION* pSession, ExampleFilter& pFilter);
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| 
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|     /**
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|      * Handle a query from the client. This is called when the client sends a query and the query has not
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|      * been blocked by any previous component in the query processing chain. The filter should do its own
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|      * processing and then send the query to the next component. If the query comes in multiple packets,
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|      * this is called for each packet.
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|      *
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|      * @param pPacket Packet containing the query, or at least a part of it
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|      * @return 0 on success. This typically depends on the later stages of the query processing chain.
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|      */
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|     int routeQuery(GWBUF* pPacket);
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| 
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| 
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|     /**
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|      * Handle a reply from server. The reply typically contains a resultset or a response to a command.
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|      * The filter should do its own processing and then send the query to the next component.
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|      * If the reply comes in multiple packets, this is called for each packet. The processing chain for
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|      * replies is the same as for queries, just walked in the opposite direction.
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|      *
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|      * @param pPacket Packet containing results
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|      * @return 0 on success. This typically depends on the later stages of the reply processing chain.
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|      */
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|     int clientReply(GWBUF* pPacket);
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| 
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| private:
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|     // Used in the create function
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|     ExampleFilterSession(MXS_SESSION* pSession, ExampleFilter& filter);
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| 
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|     ExampleFilter& m_filter;    /**< Shared filter data */
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| 
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|     uint64_t m_session_id {0};  /**< Session id */
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|     int      m_queries {0};     /**< How many queries has this session seen */
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|     int      m_replies {0};     /**< How many replies has this session seen */
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| };
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