From 5020bfd6cabb588dd34ff4171acac42c9b0e1945 Mon Sep 17 00:00:00 2001
From: Nat Lasseter <nat.lasseter@york.ac.uk>
Date: Thu, 25 Jun 2020 13:16:56 +0100
Subject: Added transactions to the collector so we can support exception
 handling on the raiders

---
 lib/longboat/collector.rb | 46 ++++++++++++++++++++++++++++++++++++++++++----
 lib/longboat/raiders.rb   | 33 +++++++++++++++++++++------------
 2 files changed, 63 insertions(+), 16 deletions(-)

(limited to 'lib')

diff --git a/lib/longboat/collector.rb b/lib/longboat/collector.rb
index 10e2f84..01bb7f0 100644
--- a/lib/longboat/collector.rb
+++ b/lib/longboat/collector.rb
@@ -1,27 +1,47 @@
 module Longboat
+  class CollectorTransactionError < Exception; end
+
   class Collector
     def initialize(config)
       @metrics = {}
       @config = config
+      @transaction = nil
     end
 
     def report!(name, value, help: nil, type: nil, labels: {}, timestamp: Time.now)
+      raise CollectorTransactionError if @tranaction.nil?
+
       name = prefix(name)
 
-      @metrics[name] ||= {help: help, type: type}
-      @metrics[name][labels] = {value: value, timestamp: timestamp}
+      @transaction[name] ||= {help: help, type: type}
+      @transaction[name][labels] = {value: value, timestamp: timestamp}
     end
 
     def redact!(name, labels: nil)
+      raise CollectorTransactionError if @tranaction.nil?
+
       name = prefix(name)
 
       if labels.nil?
-        @metrics.delete(name)
+        @transaction.delete(name)
       else
-        @metrics[name].delete(labels)
+        @transaction[name].delete(labels)
       end
     end
 
+    def begin!
+      @transaction = clone_metrics
+    end
+
+    def abort!
+      @transaction = nil
+    end
+
+    def commit!
+      @metrics = @transaction
+      @transaction = nil
+    end
+
     def prometheus_metrics
       res = ""
       @metrics.each do |name, metric|
@@ -50,5 +70,23 @@ module Longboat
     def prefix(name)
       "#{@config[:metric_prefix]}#{name}"
     end
+    
+    def clone_metrics
+      clone = {}
+
+      @metrics.each do |metric, attributes|
+        clone[metric] = {}
+        clone[metric][:help] = attributes[:help]
+        clone[metric][:type] = attributes[:type]
+
+        attributes.each do |labels, value|
+          next if [:help, :type].include?(labels)
+
+          clone[metric][labels.clone] = value.clone
+        end
+      end
+
+      clone
+    end
   end
 end
diff --git a/lib/longboat/raiders.rb b/lib/longboat/raiders.rb
index 3e6f246..2740570 100644
--- a/lib/longboat/raiders.rb
+++ b/lib/longboat/raiders.rb
@@ -21,19 +21,28 @@ module Longboat
     end
 
     def raid!
+      puts "RAID"
       @raiders.each do |name, raider|
-        start_time = Time.now
-        raider.raid
-        end_time = Time.now
-        time_taken = end_time - start_time
-
-        @collector.report!(
-          "longboat_meta_raider_runtime",
-          (time_taken.to_f * 1000).to_i,
-          help: "Time taken by a raider whilst raiding in ms",
-          type: "guage",
-          labels: {raider: name}
-        )
+        @collector.begin!
+
+        begin
+          start_time = Time.now
+          raider.raid
+          end_time = Time.now
+          time_taken = end_time - start_time
+
+          @collector.report!(
+            "longboat_meta_raider_runtime",
+            (time_taken.to_f * 1000).to_i,
+            help: "Time taken by a raider whilst raiding in ms",
+            type: "guage",
+            labels: {raider: name}
+          )
+
+          @collector.commit!
+        rescue Exception => e
+          @collector.abort!
+        end
       end
     end
 
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