From 090892db4cb37cdf4b533f959bf167b2569d50e1 Mon Sep 17 00:00:00 2001
From: Johan Wikman <johan.wikman@mariadb.com>
Date: Tue, 27 Feb 2018 21:41:08 +0200
Subject: [PATCH] MXS-1475 Add 'enabled' parameter to Cache filter

With 'enabled' it can be specified whether the cache should initially
be enabled or disabled. Useful as it is now possible to enable/disable
the cache dynamically.
---
 server/modules/filter/cache/cachefilter.cc        | 6 ++++++
 server/modules/filter/cache/cachefilter.h         | 3 +++
 server/modules/filter/cache/cachefiltersession.cc | 2 +-
 3 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/server/modules/filter/cache/cachefilter.cc b/server/modules/filter/cache/cachefilter.cc
index 1391c311b..5ad618f1d 100644
--- a/server/modules/filter/cache/cachefilter.cc
+++ b/server/modules/filter/cache/cachefilter.cc
@@ -243,6 +243,11 @@ extern "C" MXS_MODULE* MXS_CREATE_MODULE()
                 MXS_MODULE_OPT_NONE,
                 parameter_cache_in_trxs_values
             },
+            {
+                "enabled",
+                MXS_MODULE_PARAM_BOOL,
+                CACHE_DEFAULT_ENABLED
+            },
             {MXS_END_MODULE_PARAMS}
         }
     };
@@ -351,6 +356,7 @@ bool CacheFilter::process_params(char **pzOptions, MXS_CONFIG_PARAMETER *ppParam
     config.cache_in_trxs = static_cast<cache_in_trxs_t>(config_get_enum(ppParams,
                                                                         "cache_in_transactions",
                                                                         parameter_cache_in_trxs_values));
+    config.enabled = config_get_bool(ppParams, "enabled");
 
     if (!config.storage)
     {
diff --git a/server/modules/filter/cache/cachefilter.h b/server/modules/filter/cache/cachefilter.h
index 12dbfa4f7..3d61d6b2a 100644
--- a/server/modules/filter/cache/cachefilter.h
+++ b/server/modules/filter/cache/cachefilter.h
@@ -60,6 +60,8 @@
 #define CACHE_DEFAULT_STORAGE            "storage_inmemory"
 // Transaction behaviour
 #define CACHE_DEFAULT_CACHE_IN_TRXS      "all_transactions"
+// Enabled
+#define CACHE_DEFAULT_ENABLED            "true"
 
 typedef enum cache_selects
 {
@@ -92,4 +94,5 @@ typedef struct cache_config
     cache_thread_model_t thread_model; /**< Thread model. */
     cache_selects_t selects;           /**< Assume/verify that selects are cacheable. */
     cache_in_trxs_t cache_in_trxs;     /**< To cache or not to cache inside transactions. */
+    bool enabled;                      /**< Whether the cache is enabled or not. */
 } CACHE_CONFIG;
diff --git a/server/modules/filter/cache/cachefiltersession.cc b/server/modules/filter/cache/cachefiltersession.cc
index 62cd21e13..ad43bf46f 100644
--- a/server/modules/filter/cache/cachefiltersession.cc
+++ b/server/modules/filter/cache/cachefiltersession.cc
@@ -187,7 +187,7 @@ CacheFilterSession::CacheFilterSession(MXS_SESSION* pSession, Cache* pCache, cha
     , m_zUseDb(NULL)
     , m_refreshing(false)
     , m_is_read_only(true)
-    , m_enabled(true) // TODO: Add configuration variable for initial mode.
+    , m_enabled(pCache->config().enabled)
     , m_variable_added(false)
 {
     m_key.data = 0;