1 files changed, 90 insertions, 0 deletions
diff --git a/estimation-scripts/Estimators.rb b/estimation-scripts/Estimators.rb
new file mode 100644
index 0000000..1ef0c6e
--- /dev/null
+++ b/estimation-scripts/Estimators.rb
@@ -0,0 +1,90 @@
+require 'Sample'
+
+# abstract base class of all estimators
+
+class Estimator
+
+    # processes a sample
+    def process(sample)
+    end
+    
+    # returns an estimate (ETA as float)
+    # note that you must process at least one sample before this will return meaningful output
+    def estimate
+    end
+
+    # returns the name of the estimator
+    def name
+    end
+end
+
+# estimator that uses the current speed
+class CSAEstimator < Estimator
+    def process(sample)
+        @sample = sample.clone
+    end
+    
+    def estimate
+        return @sample.bytesLeft.to_f / @sample.speed
+    end
+
+    def name
+        'CurrentSpeedEstimator'
+    end
+end
+
+# estimator that uses the global average speed of the whole torrent download for estimation
+
+class GASAEstimator < Estimator
+    def process(sample)
+        @first = sample.clone if @first == nil
+        @last = sample.clone
+        @avgSpeed = Sample.averageSpeed(@first, @last)
+    end
+
+    def estimate
+        return @last.bytesLeft.to_f / @avgSpeed
+    end
+
+    def name
+        'AverageSpeedEstimator'
+    end
+end
+
+# estimator that uses the average over the last n seconds
+
+class WINXEstimator < Estimator
+
+    attr_reader :windowSize
+
+    def process(sample)
+        # remove all samples that are older than the window size. Note: samples are sorted.
+        @list.pop until @list.length <= 1 or (sample.time - @list.last.time) <= @windowSize
+
+        # prepend array with newest sample
+        @list.unshift(sample.clone)
+    end
+
+    def estimate
+
+        if @list.length > 1
+            first = @list.first
+            last = @list.last
+            return first.bytesLeft.to_f / Sample.averageSpeed(last, first) 
+        elsif @list.length == 1
+            sample = @list.first
+            return  sample.bytesLeft.to_f / sample.speed
+        elsif @list.length == 0
+            return 0
+        end
+    end
+    
+    def name
+        "MovingAverageEstimator_#{@windowSize}s"
+    end
+
+    def initialize(windowSizeInSeconds)
+        @list = Array.new
+        @windowSize = windowSizeInSeconds
+    end
+end