130 lines
3.7 KiB
C++
130 lines
3.7 KiB
C++
/*
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* Copyright (c) 2016 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: 2025-10-29
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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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// All log messages from this module are prefixed with this
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#define MXS_MODULE_NAME "examplecppfilter"
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/*
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* To use the filter in a configuration, add the following section to the config file:
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* [ExampleFilter]
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* type=filter
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* module=examplecppfilter
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* global_counts=true
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*
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* Then add the filter to a service:
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* [Read-Write-Service]
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* .
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* .
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* filters=ExampleFilter
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*/
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#include "examplefilter.hh"
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static const char CN_COUNT_GLOBALS[] = "global_counts";
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// This declares a module in MaxScale
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extern "C" MXS_MODULE* MXS_CREATE_MODULE()
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{
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static const char DESC[] = "An example filter that counts the number of queries and replies "
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"it has routed";
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static MXS_MODULE info =
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{
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MXS_MODULE_API_FILTER,
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MXS_MODULE_IN_DEVELOPMENT,
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MXS_FILTER_VERSION,
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DESC,
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"V1.0.0",
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RCAP_TYPE_STMT_INPUT, // See getCapabilities() below
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&ExampleFilter::s_object, // This is defined in the MaxScale filter template
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NULL, /* Process init. */
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NULL, /* Process finish. */
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NULL, /* Thread init. */
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NULL, /* Thread finish. */
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{
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{"an_example_parameter",MXS_MODULE_PARAM_STRING, "a-default-value"},
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{CN_COUNT_GLOBALS, MXS_MODULE_PARAM_BOOL, "true" },
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{MXS_END_MODULE_PARAMS}
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}
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};
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return &info;
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}
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ExampleFilter::ExampleFilter(const MXS_CONFIG_PARAMETER* pParams)
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{
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m_collect_global_counts = pParams->get_bool(CN_COUNT_GLOBALS);
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}
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ExampleFilter::~ExampleFilter()
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{
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}
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// static
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ExampleFilter* ExampleFilter::create(const char* zName, MXS_CONFIG_PARAMETER* pParams)
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{
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return new ExampleFilter(pParams);
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}
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ExampleFilterSession* ExampleFilter::newSession(MXS_SESSION* pSession)
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{
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return ExampleFilterSession::create(pSession, *this);
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}
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// static
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void ExampleFilter::diagnostics(DCB* pDcb) const
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{
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int queries = m_total_queries.load(std::memory_order_relaxed);
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int replies = m_total_replies.load(std::memory_order_relaxed);
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dcb_printf(pDcb, "\t\tTotal queries %i\n", queries);
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dcb_printf(pDcb, "\t\tTotal replies %i\n", replies);
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}
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// static
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json_t* ExampleFilter::diagnostics_json() const
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{
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json_t* rval = json_object();
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int queries = m_total_queries.load(std::memory_order_relaxed);
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int replies = m_total_replies.load(std::memory_order_relaxed);
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json_object_set_new(rval, "total_queries", json_integer(queries));
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json_object_set_new(rval, "total_replies", json_integer(replies));
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return rval;
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}
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// static
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uint64_t ExampleFilter::getCapabilities()
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{
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// Tells the protocol that the filter expects complete queries from client, that is, a query cannot be
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// sent in parts.
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return RCAP_TYPE_STMT_INPUT;
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// Try the following to also expect replies to be complete. This can cause problems if the server sends
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// a really big (e.g. 1 GB) resultset.
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// return RCAP_TYPE_STMT_INPUT | RCAP_TYPE_RESULTSET_OUTPUT;
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}
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void ExampleFilter::query_seen()
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{
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if (m_collect_global_counts)
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{
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m_total_queries.fetch_add(1, std::memory_order_relaxed);
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}
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}
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void ExampleFilter::reply_seen()
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{
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if (m_collect_global_counts)
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{
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m_total_replies.fetch_add(1, std::memory_order_relaxed);
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}
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}
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