json.rb in visage-app-0.9.0.pre1

- old
+ new

@@ -7,27 +7,23 @@
 require 'yajl'
 
 # Exposes RRDs as JSON.
 #
 # A loose shim onto RRDtool, with some extra logic to normalise the data.
-# Also provides a recommended color for rendering the data in a line graph.
 #
 class CollectdJSON
 
   def initialize(opts={})
     @rrddir = opts[:rrddir] || CollectdJSON.rrddir
-    @fallback_colors = opts[:fallback_colors] || {}
-    @used_fallbacks = []
   end
 
   # Entry point.
   def json(opts={})
     host             = opts[:host]
     plugin           = opts[:plugin]
     plugin_instances = opts[:plugin_instances][/\w.*/]
     instances        = plugin_instances.blank? ? '*' : '{' + plugin_instances.split('/').join(',') + '}'
-    @colors          = opts[:plugin_colors]
     @plugin_names = []
 
     rrdglob = "#{@rrddir}/#{host}/#{plugin}/#{instances}.rrd"
     plugin_offset = @rrddir.size + 1 + host.size + 1
 
@@ -64,63 +60,36 @@
 
       # A single rrd can have multiple data sets (multiple metrics within
       # the same file). Separate the metrics.
       rrd_data.each_pair do |source, metric|
 
-        # filter out NaNs, so yajl doesn't choke
+        # Filter out NaNs and weirdly massive values so yajl doesn't choke
         metric.map! do |datapoint|
-          (!datapoint || datapoint.nan?) ? 0.0 : datapoint
+          case
+          when datapoint && datapoint.nan?
+            @tripped = true
+            @last_valid
+          when @tripped
+            @last_valid
+          else
+            @last_valid = datapoint
+          end
         end
 
-        # Sometimes the last value from the RRD is ridiculously large.
-        metric.slice!(-1)
+        metric[-1] = 0.0
 
-        color = color_for(:host => data[:host],
-                          :plugin => data[:plugin],
-                          :instance => data[:instance],
-                          :metric => source)
-
         structure[data[:host]] ||= {}
         structure[data[:host]][data[:plugin]] ||= {}
         structure[data[:host]][data[:plugin]][data[:instance]] ||= {}
         structure[data[:host]][data[:plugin]][data[:instance]][source] ||= {}
         structure[data[:host]][data[:plugin]][data[:instance]][source][:start]  ||= data[:start]
         structure[data[:host]][data[:plugin]][data[:instance]][source][:finish] ||= data[:finish]
         structure[data[:host]][data[:plugin]][data[:instance]][source][:data]   ||= metric
-        structure[data[:host]][data[:plugin]][data[:instance]][source][:color]  ||= color
       end
     end
 
     encoder = Yajl::Encoder.new
     encoder.encode(structure)
-  end
-
-  # We append the recommended line color onto data set, so the javascript
-  # doesn't try and have to work it out. This lets us use all sorts of funky
-  # fallback logic when determining what colours should be used.
-  def color_for(opts={})
-
-    plugin   = opts[:plugin]
-    instance = opts[:instance]
-    metric   = opts[:metric]
-
-    return fallback_color unless plugin
-    return color_for(opts.merge(:plugin => plugin[/(.+)-.+$/, 1])) unless @colors[plugin]
-    return fallback_color unless instance
-    return color_for(opts.merge(:instance => instance[/(.+)-.+$/, 1])) unless @colors[plugin][instance]
-    return @colors[plugin][instance][metric] if @colors[plugin][instance]
-    return fallback_color
-  end
-
-  def fallback_color
-    fallbacks = @fallback_colors.to_a.sort_by {|pair| pair[1]['fallback_order'] }
-    fallback = fallbacks.find { |color| !@used_fallbacks.include?(color) }
-    unless fallback
-      @used_fallbacks = []
-      fallback = fallbacks.find { |color| !@used_fallbacks.include?(color) }
-    end
-    @used_fallbacks << fallback
-    fallback[1]['color'] || "#000"
   end
 
   class << self
     attr_writer :rrddir
 