Add TrxBoundaryMatcher

A class capble of detecting statements that change the transaction
state and autocommit mode. The detection is done using regexes.

There is still some expanding and optimization to be done.

server/core/maxscale/trxboundarymatcher.hh

@@ -0,0 +1,87 @@
+#pragma once
+/*
+ * Copyright (c) 2016 MariaDB Corporation Ab
+ *
+ * Use of this software is governed by the Business Source License included
+ * in the LICENSE.TXT file and at www.mariadb.com/bsl11.
+ *
+ * Change Date: 2019-07-01
+ *
+ * On the date above, in accordance with the Business Source License, use
+ * of this software will be governed by version 2 or later of the General
+ * Public License.
+ */
+
+#include <maxscale/cppdefs.hh>
+#include <maxscale/pcre2.h>
+#include <maxscale/query_classifier.h>
+
+namespace maxscale
+{
+
+/**
+ * @class TrxBoundaryMatcher
+ *
+ * @ TrxBoundaryMatcher is a class capable of, using regexes, to recognize
+ * and return the correct type mask of statements affecting the transaction
+ * state and* autocommit mode.
+ */
+class TrxBoundaryMatcher
+{
+public:
+    /**
+     * To be called once at process startup. After a successful call,
+     * @type_mask_of() can be used in the calling thread.
+     *
+     * @return True, if the initialization succeeded, false otherwise.
+     */
+    static bool process_init();
+
+    /**
+     * To be called once at process shut down.
+     */
+    static void process_end();
+
+    /**
+     * To be called once in each thread, other that the one where @process_init()
+     * was called. After a successful call, @type_mask_of() can be used in the
+     * calling thread.
+     *
+     * @return True, if the initialization succeeded, false otherwise.
+     */
+    static bool thread_init();
+
+    /**
+     * To be called once at thread shut down.
+     */
+    static void thread_end();
+
+    /**
+     * Return the type mask of a statement, provided the statement affects
+     * transaction state or autocommit mode.
+     *
+     * @param pSql  Sql statement.
+     * @param len   Length of @c pSql.
+     *
+     * @return The corresponding type mask or 0, if the statement does not
+     *         affect transaction state or autocommit mode.
+     */
+    static uint32_t type_mask_of(const char* pSql, size_t len);
+
+    /**
+     * Return the type mask of a statement, provided the statement affects
+     * transaction state or autocommit mode.
+     *
+     * @param pBuf A COM_QUERY
+     *
+     * @return The corresponding type mask or 0, if the statement does not
+     *         affect transaction state or autocommit mode.
+     */
+    static uint32_t type_mask_of(GWBUF* pBuf);
+
+private:
+    TrxBoundaryMatcher(const TrxBoundaryMatcher&);
+    TrxBoundaryMatcher& operator = (const TrxBoundaryMatcher&);
+};
+
+}