json.rb in visage-app-2.0.0

- old
+ new
@@ -8,135 +8,132 @@
 
 # Exposes RRDs as JSON.
 #
 # A loose shim onto RRDtool, with some extra logic to normalise the data.
 #
-class CollectdJSON
+module Visage
+  module Collectd
+    class JSON
 
-  def initialize(opts={})
-    @rrddir = opts[:rrddir] || CollectdJSON.rrddir
-    @types  = opts[:types]  || CollectdJSON.types
-  end
+      def initialize(opts={})
+        @rrddir = opts[:rrddir] || Visage::Collectd::JSON.rrddir
+        @types  = opts[:types]  || Visage::Collectd::JSON.types
+      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(',') + '}'
-    rrdglob          = "#{@rrddir}/#{host}/#{plugin}/#{instances}.rrd"
+      def parse_time(time, opts={})
+        case
+        when time && time.index('.')
+          time.split('.').first.to_i
+        when time
+          time.to_i
+        else
+         opts[:default] || Time.now.to_i
+        end
+      end
 
-    start = case
-    when opts[:start] && opts[:start].index('.')
-      opts[:start].split('.').first
-    when opts[:start]
-      opts[:start]
-    else
-      (Time.now - 3600).to_i
-    end
+      # Entry point.
+      def json(opts={})
+        host      = opts[:host]
+        plugin    = opts[:plugin]
+        instances = opts[:instances][/\w.*/]
+        instances = instances.blank? ? '*' : '{' + instances.split('/').join(',') + '}'
+        rrdglob   = "#{@rrddir}/#{host}/#{plugin}/#{instances}.rrd"
+        finish    = parse_time(opts[:finish])
+        start     = parse_time(opts[:start],  :default => (finish - 3600 || (Time.now - 3600).to_i))
+        data      = []
 
-    finish = case
-    when opts[:finish] && opts[:finish].index('.')
-      opts[:finish].split('.').first
-    when opts[:finish]
-      opts[:finish]
-    else
-      Time.now.to_i
-    end
+        Dir.glob(rrdglob).map do |rrdname|
+          parts         = rrdname.gsub(/#{@rrddir}\//, '').split('/')
+          host_name     = parts[0]
+          plugin_name   = parts[1]
+          instance_name = File.basename(parts[2], '.rrd')
+          rrd           = Errand.new(:filename => rrdname)
 
-    data = []
+          data << {  :plugin => plugin_name, :instance => instance_name,
+                     :host   => host_name,
+                     :start  => start,
+                     :finish => finish,
+                     :rrd    => rrd }
+        end
 
-    Dir.glob(rrdglob).map do |rrdname|
-      parts         = rrdname.gsub(/#{@rrddir}\//, '').split('/')
-      host_name     = parts[0]
-      plugin_name   = parts[1]
-      instance_name = File.basename(parts[2], '.rrd')
-      rrd = Errand.new(:filename => rrdname)
+        encode(data)
+      end
 
+      private
+      # Attempt to structure the JSON reasonably sanely, so the consumer (i.e. a
+      # browser) doesn't have to do a lot of computationally expensive work.
+      def encode(datas)
 
-      data << {  :plugin => plugin_name, :instance => instance_name,
-                 :host   => host_name,
-                 :start  => start,
-                 :finish => finish,
-                 :rrd    => rrd }
-    end
+        structure = {}
+        datas.each do |data|
+          fetch    = data[:rrd].fetch(:function => "AVERAGE",
+                                      :start    => data[:start],
+                                      :finish   => data[:finish])
+          rrd_data = fetch[:data]
 
-    encode(data)
-  end
+          # A single rrd can have multiple data sets (multiple metrics within
+          # the same file). Separate the metrics.
+          rrd_data.each_pair do |source, metric|
 
-  private
-  # Attempt to structure the JSON reasonably sanely, so the consumer (i.e. a
-  # browser) doesn't have to do a lot of computationally expensive work.
-  def encode(datas)
+            # Filter out NaNs and weirdly massive values so yajl doesn't choke
+            metric.map! do |datapoint|
+              case
+              when datapoint && datapoint.nan?
+                @tripped = true
+                @last_valid
+              when @tripped
+                @last_valid
+              else
+                @last_valid = datapoint
+              end
+            end
 
-    structure = {}
-    datas.each do |data|
-      fetch = data[:rrd].fetch(:function => "AVERAGE",
-                               :start => data[:start],
-                               :finish => data[:finish])
-      rrd_data = fetch[:data]
+            # Last value is always wack. Set to 0, so the timescale isn't off by 1.
+            metric[-1] = 0.0
+            host     = data[:host]
+            plugin   = data[:plugin]
+            instance = data[:instance]
+            start    = data[:start].to_i
+            finish   = data[:finish].to_i
 
-      # A single rrd can have multiple data sets (multiple metrics within
-      # the same file). Separate the metrics.
-      rrd_data.each_pair do |source, metric|
+            structure[host] ||= {}
+            structure[host][plugin] ||= {}
+            structure[host][plugin][instance] ||= {}
+            structure[host][plugin][instance][source] ||= {}
+            structure[host][plugin][instance][source][:start]  ||= start
+            structure[host][plugin][instance][source][:finish] ||= finish
+            structure[host][plugin][instance][source][:data]   ||= metric
 
-        # Filter out NaNs and weirdly massive values so yajl doesn't choke
-        metric.map! do |datapoint|
-          case
-          when datapoint && datapoint.nan?
-            @tripped = true
-            @last_valid
-          when @tripped
-            @last_valid
-          else
-            @last_valid = datapoint
           end
         end
 
-        # Last value is always wack. Set to 0, so the timescale isn't off by 1.
-        metric[-1] = 0.0
-        host     = data[:host]
-        plugin   = data[:plugin]
-        instance = data[:instance]
-        start    = data[:start].to_i
-        finish   = data[:finish].to_i
-
-        structure[host] ||= {}
-        structure[host][plugin] ||= {}
-        structure[host][plugin][instance] ||= {}
-        structure[host][plugin][instance][source] ||= {}
-        structure[host][plugin][instance][source][:start]  ||= start
-        structure[host][plugin][instance][source][:finish] ||= finish
-        structure[host][plugin][instance][source][:data]   ||= metric
-
+        encoder = Yajl::Encoder.new
+        encoder.encode(structure)
       end
-    end
 
-    encoder = Yajl::Encoder.new
-    encoder.encode(structure)
-  end
+      class << self
+        attr_writer :rrddir
 
-  class << self
-    attr_writer :rrddir
+        def rrddir
+          @rrddir ||= Visage::Config.rrddir
+        end
 
-    def rrddir
-      @rrddir ||= Visage::Config.rrddir
-    end
+        def types
+          @types  ||= Visage::Config.types
+        end
 
-    def types
-      @types  ||= Visage::Config.types
-    end
+        def hosts
+          if @rrddir
+            Dir.glob("#{@rrddir}/*").map {|e| e.split('/').last }.sort
+          end
+        end
 
-    def hosts
-      if @rrddir
-        Dir.glob("#{@rrddir}/*").map {|e| e.split('/').last }.sort
+        def plugins(opts={})
+          host = opts[:host] || '*'
+          Dir.glob("#{@rrddir}/#{host}/*").map {|e| e.split('/').last }.sort
+        end
+
       end
-    end
 
-    def plugins(opts={})
-      host = opts[:host] || '*'
-      Dir.glob("#{@rrddir}/#{host}/*").map {|e| e.split('/').last }.sort
-    end
-
-  end
-
-end
+    end # class JSON
+  end # module Collectd
+end # module Visage