predict: don't auto-load stats if not needed

and make docs conform to the reality.

diff --git a/modules/predict/README.rst b/modules/predict/README.rst
index bd5a8dd4868787bcf179344f320310c40b961e30..6c4b442ad834588413d55dd1dd49b944c5fcafdd 100644 (file)
--- a/modules/predict/README.rst
+++ b/modules/predict/README.rst
@@ -15,8 +15,6 @@ ahead of time. This is helpful to minimize the perceived latency and keeps the c
 Example configuration
 ^^^^^^^^^^^^^^^^^^^^^
 
-.. warning:: This module requires 'stats' module to be present and loaded.
-
 .. code-block:: lua
 
        modules = {
@@ -29,7 +27,9 @@ Example configuration
 Defaults are 15 minutes window, 6 hours period.
 
 .. tip:: Use period 0 to turn off prediction and just do prefetching of expiring records.
-    That works even without the 'stats' module.
+    That works even without the :ref:`stats <mod-stats>` module.
+
+.. note:: Otherwise this module requires :ref:`stats <mod-stats>` module and loads it if not present.
 
 Exported metrics
 ^^^^^^^^^^^^^^^^
@@ -45,7 +45,7 @@ Properties
 ^^^^^^^^^^
 
 .. function:: predict.config({ window = 15, period = 24})
-  
+
   Reconfigure the predictor to given tracking window and period length. Both parameters are optional.
   Window length is in minutes, period is a number of windows that can be kept in memory.
   e.g. if a ``window`` is 15 minutes, a ``period`` of "24" means 6 hours.

diff --git a/modules/predict/predict.lua b/modules/predict/predict.lua
index 7dd38754c56254865ab7ad24c292e3937d5fab17..846d4ef7d53867f64e364d66631d393938fcbd51 100644 (file)
--- a/modules/predict/predict.lua
+++ b/modules/predict/predict.lua
@@ -13,8 +13,6 @@ local predict = {
        log = {},
 }
 
--- Load dependent modules
-if not stats then modules.load('stats') end
 
 -- Calculate next sample with jitter [1-2/5 of window]
 local function next_event()
@@ -163,6 +161,8 @@ function predict.config(config)
        if type(config) ~= 'table' then return end
        if config.window then predict.window = config.window end
        if config.period then predict.period = config.period end
+       -- Load dependent modules
+       if (predict.period or 0) ~= 0 and not stats then modules.load('stats') end
        -- Reinitialize to reset timers
        predict.deinit()
        predict.init()

diff --git a/modules/predict/tests/predict.test.lua b/modules/predict/tests/predict.test.lua
index e4694b635a6f76e6c0d2c9a50ffc1099bbbf5799..10431045e60d4c4bfef37a83e9dc1fb8c6024b6e 100644 (file)
--- a/modules/predict/tests/predict.test.lua
+++ b/modules/predict/tests/predict.test.lua
@@ -1,5 +1,5 @@
 -- setup resolver
-modules = { 'predict' }
+modules = { 'predict', 'stats' }
 
 -- mock global functions
 local resolve_count = 0
@@ -57,4 +57,4 @@ end
 return {
        test_predict_drain,
        test_predict_process
-}
\ No newline at end of file
+}