MXS-1475 Add test case for @maxscale.cache.[use|populate]

Also extend logging.

maxscale-system-test/cache_runtime.cpp

@@ -0,0 +1,216 @@
+/*
+ * 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: 2020-01-01
+ *
+ * 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 <iostream>
+#include <string>
+#include <vector>
+#include "testconnections.h"
+
+using namespace std;
+
+namespace
+{
+
+void drop(TestConnections& test)
+{
+    MYSQL* pMysql = test.maxscales->conn_rwsplit[0];
+
+    string stmt("DROP TABLE IF EXISTS cache_test");
+
+    cout << stmt << endl;
+    test.try_query(pMysql, stmt.c_str());
+}
+
+void create(TestConnections& test)
+{
+    drop(test);
+
+    MYSQL* pMysql = test.maxscales->conn_rwsplit[0];
+
+    string stmt("CREATE TABLE cache_test (a INT)");
+
+    cout << stmt << endl;
+    test.try_query(pMysql, stmt.c_str());
+}
+
+void insert(TestConnections& test)
+{
+    MYSQL* pMysql = test.maxscales->conn_rwsplit[0];
+
+    string stmt("INSERT INTO cache_test VALUES (1)");
+
+    cout << stmt << endl;
+    test.try_query(pMysql, stmt.c_str());
+}
+
+void update(TestConnections& test, int value)
+{
+    MYSQL* pMysql = test.maxscales->conn_rwsplit[0];
+
+    string stmt("UPDATE cache_test SET a=");
+    stmt += std::to_string(value);
+
+    cout << stmt << endl;
+    test.try_query(pMysql, stmt.c_str());
+}
+
+void select(TestConnections& test, int* pValue)
+{
+    MYSQL* pMysql = test.maxscales->conn_rwsplit[0];
+
+    string stmt("SELECT * FROM cache_test");
+
+    cout << stmt << endl;
+
+    if (mysql_query(pMysql, stmt.c_str()) == 0)
+    {
+        if (mysql_field_count(pMysql) != 0)
+        {
+            size_t nRows = 0;
+
+            do
+            {
+                MYSQL_RES* pRes = mysql_store_result(pMysql);
+                MYSQL_ROW row = mysql_fetch_row(pRes);
+                *pValue = atoi(row[0]);
+                mysql_free_result(pRes);
+                ++nRows;
+            }
+            while (mysql_next_result(pMysql) == 0);
+
+            test.assert(nRows == 1, "Unexpected number of rows: %u", nRows);
+        }
+    }
+    else
+    {
+        test.assert(false, "SELECT failed.");
+    }
+}
+
+namespace Cache
+{
+
+enum What
+{
+    POPULATE,
+    USE
+};
+
+}
+
+void set(TestConnections& test, Cache::What what, bool value)
+{
+    MYSQL* pMysql = test.maxscales->conn_rwsplit[0];
+
+    string stmt("SET @maxscale.cache.");
+    stmt += ((what == Cache::POPULATE) ? "populate" : "use");
+    stmt += "=";
+    stmt += (value ? "true" : "false");
+
+    cout << stmt << endl;
+    test.try_query(pMysql, stmt.c_str());
+}
+
+}
+
+
+namespace
+{
+
+void init(TestConnections& test)
+{
+    create(test);
+    insert(test);
+}
+
+void run(TestConnections& test)
+{
+    init(test);
+
+    MYSQL* pMysql = test.maxscales->conn_rwsplit[0];
+
+    int value;
+
+    // Let's populate the cache.
+    set(test, Cache::POPULATE, true);
+    set(test, Cache::USE, false);
+    select(test, &value);
+    test.assert(value == 1, "Initial value was not 1.");
+
+    // And update the real value.
+    update(test, 2); // Now the cache contains 1 and the db 2.
+
+    // With @maxscale.cache.use==false we should get the updated value.
+    set(test, Cache::POPULATE, false);
+    set(test, Cache::USE, false);
+    select(test, &value);
+    test.assert(value == 2, "The value received was not the latest one.");
+
+    // With @maxscale.cache.use==true we should get the old one, since
+    // it was not updated above as @maxscale.cache.populate==false.
+    set(test, Cache::POPULATE, false);
+    set(test, Cache::USE, true);
+    select(test, &value);
+    test.assert(value == 1, "The value received was not the populated one.");
+
+    // The hard_ttl is 8, so we sleep(10) seconds to ensure that TTL has passed.
+    cout << "Sleeping 10 seconds." << endl;
+    sleep(10);
+
+    // With @maxscale.cache.use==true we should now get the latest value.
+    // The value in the cache is stale, so it will be updated even if
+    // @maxscale.cache.populate==false.
+    set(test, Cache::POPULATE, false);
+    set(test, Cache::USE, true);
+    select(test, &value);
+    test.assert(value == 2, "The cache was not updated even if TTL was passed.");
+
+    // Let's update again
+    update(test, 3);
+
+    // And fetch again. Should still be 2, as the item in the cache is not stale.
+    set(test, Cache::POPULATE, false);
+    set(test, Cache::USE, true);
+    select(test, &value);
+    test.assert(value == 2, "New value %d, although the value in the cache is not stale.", value);
+
+    // Force an update.
+    set(test, Cache::POPULATE, true);
+    set(test, Cache::USE, false);
+    select(test, &value);
+    test.assert(value == 3, "Did not get new value.");
+
+    // And check that the cache indeed was updated, but update the DB first.
+    update(test, 4);
+
+    set(test, Cache::POPULATE, false);
+    set(test, Cache::USE, true);
+    select(test, &value);
+    test.assert(value == 3, "Got a newer value than expected.");
+}
+
+}
+
+int main(int argc, char* argv[])
+{
+    std::ios::sync_with_stdio(true);
+
+    TestConnections test(argc, argv);
+
+    if (test.maxscales->connect_rwsplit() == 0)
+    {
+        run(test);
+    }
+
+    return test.global_result;
+}