Allow query classifier to initialize itself

The process and thread initialization/finalization of the query
classifier plugins is handled using the process and thread
initialization/finalization functions in the module object.

However, the top-level query classifier will also need to perform
process and thread initialization when transaction boundaries are
detected using regular expressions.

include/maxscale/query_classifier.h

@@ -19,6 +19,16 @@ MXS_BEGIN_DECLS
 
 #define QUERY_CLASSIFIER_VERSION {1, 1, 0}
 
+/**
+ * qc_init_kind_t specifies what kind of initialization should be performed.
+ */
+typedef enum qc_init_kind
+{
+    QC_INIT_SELF   = 0x01, /*< Initialize/finalize the query classifier itself. */
+    QC_INIT_PLUGIN = 0x02, /*< Initialize/finalize the plugin. */
+    QC_INIT_BOTH   = 0x03
+} qc_init_kind_t;
+
 /**
  * qc_query_type_t defines bits that provide information about a
  * particular statement.
@@ -377,11 +387,14 @@ bool qc_setup(const char* plugin_name, const char* plugin_args);
  *
  * MaxScale calls this functions, so plugins should not do that.
  *
+ * @param kind  What kind of initialization should be performed.
+ *              Combination of qc_init_kind_t.
+ *
  * @return True, if the process wide initialization could be performed.
  *
  * @see qc_process_end qc_thread_init
  */
-bool qc_process_init(void);
+bool qc_process_init(uint32_t kind);
 
 /**
  * Finalizes the query classifier.
@@ -390,9 +403,12 @@ bool qc_process_init(void);
  * by a call to this function. MaxScale calls this function, so plugins
  * should not do that.
  *
+ * @param kind  What kind of finalization should be performed.
+ *              Combination of qc_init_kind_t.
+ *
  * @see qc_process_init qc_thread_end
  */
-void qc_process_end(void);
+void qc_process_end(uint32_t kind);
 
 /**
  * Loads a particular query classifier.
@@ -426,11 +442,14 @@ void qc_unload(QUERY_CLASSIFIER* classifier);
  *
  * MaxScale calls this function, so plugins should not do that.
  *
+ * @param kind  What kind of initialization should be performed.
+ *              Combination of qc_init_kind_t.
+ *
  * @return True if the initialization succeeded, false otherwise.
  *
  * @see qc_thread_end
  */
-bool qc_thread_init(void);
+bool qc_thread_init(uint32_t kind);
 
 /**
  * Performs thread finalization needed by the query classifier.
@@ -439,9 +458,12 @@ bool qc_thread_init(void);
  *
  * MaxScale calls this function, so plugins should not do that.
  *
+ * @param kind  What kind of finalization should be performed.
+ *              Combination of qc_init_kind_t.
+ *
  * @see qc_thread_init
  */
-void qc_thread_end(void);
+void qc_thread_end(uint32_t kind);
 
 /**
  * Parses the statement in the provided buffer and returns a value specifying

query_classifier/test/canonical_tests/canonizer.c

@@ -47,7 +47,7 @@ int main(int argc, char** argv)
     set_process_datadir(strdup("/tmp"));
 
     qc_setup("qc_sqlite", NULL);
-    qc_process_init();
+    qc_process_init(QC_INIT_BOTH);
 
     infile = fopen(argv[1], "rb");
     outfile = fopen(argv[2], "wb");
@@ -83,6 +83,6 @@ int main(int argc, char** argv)
     }
     fclose(infile);
     fclose(outfile);
-    qc_process_end();
+    qc_process_end(QC_INIT_BOTH);
     return 0;
 }

query_classifier/test/classify.c

@@ -314,10 +314,10 @@ int main(int argc, char** argv)
 
         if (mxs_log_init(NULL, ".", MXS_LOG_TARGET_DEFAULT))
         {
-            if (qc_setup(lib, NULL) && qc_process_init())
+            if (qc_setup(lib, NULL) && qc_process_init(QC_INIT_BOTH))
             {
                 rc = run(input_name, expected_name);
-                qc_process_end();
+                qc_process_end(QC_INIT_BOTH);
             }
             else
             {

query_classifier/test/crash_qc_sqlite.c

@@ -41,7 +41,7 @@ int main()
 
     set_libdir(strdup("../qc_sqlite"));
 
-    if (qc_setup("qc_sqlite", NULL) && qc_process_init())
+    if (qc_setup("qc_sqlite", NULL) && qc_process_init(QC_INIT_BOTH))
     {
         const char s[] = "SELECT @@global.max_allowed_packet";
 
@@ -53,7 +53,7 @@ int main()
         // code generator.
         qc_parse(stmt);
 
-        qc_process_end();
+        qc_process_end(QC_INIT_BOTH);
 
         rv = EXIT_SUCCESS;
     }

server/core/query_classifier.c

@@ -38,7 +38,6 @@ static const char default_qc_name[] = "qc_sqlite";
 
 static QUERY_CLASSIFIER* classifier;
 
-
 bool qc_setup(const char* plugin_name, const char* plugin_args)
 {
     QC_TRACE();
@@ -67,21 +66,31 @@ bool qc_setup(const char* plugin_name, const char* plugin_args)
     return (rv == QC_RESULT_OK) ? true : false;
 }
 
-bool qc_process_init(void)
+bool qc_process_init(uint32_t kind)
 {
     QC_TRACE();
     ss_dassert(classifier);
 
-    return classifier->qc_process_init() == 0;
+    bool rc = true;
+
+    if (kind & QC_INIT_PLUGIN)
+    {
+        rc = classifier->qc_process_init() == 0;
+    }
+
+    return rc;
 }
 
-void qc_process_end(void)
+void qc_process_end(uint32_t kind)
 {
     QC_TRACE();
     ss_dassert(classifier);
 
-    classifier->qc_process_end();
+    if (kind & QC_INIT_PLUGIN)
-    classifier = NULL;
+    {
+        classifier->qc_process_end();
+        classifier = NULL;
+    }
 }
 
 QUERY_CLASSIFIER* qc_load(const char* plugin_name)
@@ -106,20 +115,30 @@ void qc_unload(QUERY_CLASSIFIER* classifier)
     // TODO: actually can unload something.
 }
 
-bool qc_thread_init(void)
+bool qc_thread_init(uint32_t kind)
 {
     QC_TRACE();
     ss_dassert(classifier);
 
-    return classifier->qc_thread_init() == 0;
+    bool rc = true;
+
+    if (kind & QC_INIT_PLUGIN)
+    {
+        rc = classifier->qc_thread_init() == 0;
+    }
+
+    return rc;
 }
 
-void qc_thread_end(void)
+void qc_thread_end(uint32_t kind)
 {
     QC_TRACE();
     ss_dassert(classifier);
 
-    return classifier->qc_thread_end();
+    if (kind & QC_INIT_PLUGIN)
+    {
+        classifier->qc_thread_end();
+    }
 }
 
 qc_parse_result_t qc_parse(GWBUF* query)

server/modules/filter/cache/test/testkeygeneration.cc

@@ -127,7 +127,7 @@ int main(int argc, char* argv[])
     {
         if (mxs_log_init(NULL, ".", MXS_LOG_TARGET_DEFAULT))
         {
-            if (qc_setup(NULL, NULL) && qc_process_init())
+            if (qc_setup(NULL, NULL) && qc_process_init(QC_INIT_BOTH))
             {
                 const char* zModule = argv[1];
 
@@ -158,7 +158,7 @@ int main(int argc, char* argv[])
                     cerr << "error: Could not initialize factory." << endl;
                 }
 
-                qc_process_end();
+                qc_process_end(QC_INIT_BOTH);
             }
             else
             {

server/modules/filter/cache/test/testrules.cc

@@ -237,12 +237,12 @@ int main()
     if (mxs_log_init(NULL, ".", MXS_LOG_TARGET_DEFAULT))
     {
         set_libdir(MXS_STRDUP_A("../../../../../query_classifier/qc_sqlite/"));
-        if (qc_setup("qc_sqlite", "") && qc_process_init())
+        if (qc_setup("qc_sqlite", "") && qc_process_init(QC_INIT_BOTH))
         {
             set_libdir(MXS_STRDUP_A("../"));
             rc = test();
 
-            qc_process_end();
+            qc_process_end(QC_INIT_BOTH);
         }
         else
         {

server/modules/filter/cache/test/teststorage.cc

@@ -50,7 +50,7 @@ int TestStorage::run(int argc, char** argv)
     {
         if (mxs_log_init(NULL, ".", MXS_LOG_TARGET_DEFAULT))
         {
-            if (qc_setup(NULL, NULL) && qc_process_init())
+            if (qc_setup(NULL, NULL) && qc_process_init(QC_INIT_BOTH))
             {
                 const char* zModule = NULL;
                 size_t threads = m_threads;
@@ -113,6 +113,8 @@ int TestStorage::run(int argc, char** argv)
                 {
                     cerr << "error: Could not initialize factory " << zModule << "." << endl;
                 }
+
+                qc_process_end(QC_INIT_BOTH);
             }
             else
             {