1 files changed, 102 insertions, 0 deletions
diff --git a/lib/gitlab/metrics.rb b/lib/gitlab/metrics.rb
new file mode 100644
index 00000000000..ee88ab34d6c
--- /dev/null
+++ b/lib/gitlab/metrics.rb
@@ -0,0 +1,102 @@
+module Gitlab
+  module Metrics
+    extend Gitlab::CurrentSettings
+
+    RAILS_ROOT   = Rails.root.to_s
+    METRICS_ROOT = Rails.root.join('lib', 'gitlab', 'metrics').to_s
+    PATH_REGEX   = /^#{RAILS_ROOT}\/?/
+
+    def self.settings
+      @settings ||= {
+        enabled:               current_application_settings[:metrics_enabled],
+        pool_size:             current_application_settings[:metrics_pool_size],
+        timeout:               current_application_settings[:metrics_timeout],
+        method_call_threshold: current_application_settings[:metrics_method_call_threshold],
+        host:                  current_application_settings[:metrics_host],
+        username:              current_application_settings[:metrics_username],
+        password:              current_application_settings[:metrics_password],
+        port:                  current_application_settings[:metrics_port]
+      }
+    end
+
+    def self.enabled?
+      settings[:enabled] || false
+    end
+
+    def self.mri?
+      RUBY_ENGINE == 'ruby'
+    end
+
+    def self.method_call_threshold
+      # This is memoized since this method is called for every instrumented
+      # method. Loading data from an external cache on every method call slows
+      # things down too much.
+      @method_call_threshold ||= settings[:method_call_threshold]
+    end
+
+    def self.pool
+      @pool
+    end
+
+    # Returns a relative path and line number based on the last application call
+    # frame.
+    def self.last_relative_application_frame
+      frame = caller_locations.find do |l|
+        l.path.start_with?(RAILS_ROOT) && !l.path.start_with?(METRICS_ROOT)
+      end
+
+      if frame
+        return frame.path.sub(PATH_REGEX, ''), frame.lineno
+      else
+        return nil, nil
+      end
+    end
+
+    def self.submit_metrics(metrics)
+      prepared = prepare_metrics(metrics)
+
+      pool.with do |connection|
+        prepared.each do |metric|
+          begin
+            connection.write_points([metric])
+          rescue StandardError
+          end
+        end
+      end
+    end
+
+    def self.prepare_metrics(metrics)
+      metrics.map do |hash|
+        new_hash = hash.symbolize_keys
+
+        new_hash[:tags].each do |key, value|
+          if value.blank?
+            new_hash[:tags].delete(key)
+          else
+            new_hash[:tags][key] = escape_value(value)
+          end
+        end
+
+        new_hash
+      end
+    end
+
+    def self.escape_value(value)
+      value.to_s.gsub('=', '\\=')
+    end
+
+    # When enabled this should be set before being used as the usual pattern
+    # "@foo ||= bar" is _not_ thread-safe.
+    if enabled?
+      @pool = ConnectionPool.new(size: settings[:pool_size], timeout: settings[:timeout]) do
+        host = settings[:host]
+        user = settings[:username]
+        pw   = settings[:password]
+        port = settings[:port]
+
+        InfluxDB::Client.
+          new(udp: { host: host, port: port }, username: user, password: pw)
+      end
+    end
+  end
+end