statistics: support rrdtool's alt_autoscale and alt_autoscale_max options

Implement support for alternative scaling of the y-axis.
By default, rrdtool will autoscale to 1,2,5,10,20,50,100,200,... etc.,
which is not always suitable (e.g. memory charts for device with 128 MB).

Rrdtool 1.0.50 already supports alternative autoscaling that creates
a tighter y-axis. Implement graph-level options in Luci statistics to
support those boolean options as "alt_autoscale" and "alt_autoscale_max".

info at http://oss.oetiker.ch/rrdtool/doc/rrdgraph.en.html

Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>
(cherry picked from commit 86ff4bd3a4a39674c51bd52576a0a87e803a7c53)

diff --git a/applications/luci-app-statistics/luasrc/statistics/rrdtool.lua b/applications/luci-app-statistics/luasrc/statistics/rrdtool.lua
index 1f8f4ff88b53b3e0792e7b513422f40ba2f19b8e..d8317a8177f69c041c02e3a1de40c1d98d0123dc 100644 (file)
--- a/applications/luci-app-statistics/luasrc/statistics/rrdtool.lua
+++ b/applications/luci-app-statistics/luasrc/statistics/rrdtool.lua
@@ -457,6 +457,12 @@ function Graph._generic( self, opts, plugin, plugin_instance, dtype, index )
                        _ti ( _args, "-X" )
                        _ti ( _args, opts.units_exponent )
                end
+               if opts.alt_autoscale then
+                       _ti ( _args, "-A" )
+               end
+               if opts.alt_autoscale_max then
+                       _ti ( _args, "-M" )
+               end
 
                -- store additional rrd options
                if opts.rrdopts then