gems: include vendored metrisk without hitime dependency

hitime is only needed for Metriks::Timer and requires native extensions.
Those do not compile with default settings under Ubuntu 26.04 or Alpine 3.24.

lib/metriks/registry.rb

@@ -0,0 +1,127 @@
+# Vendored from metriks 0.9.9.8 — https://github.com/eric/metriks
+# Copyright (c) 2012 Eric Lindvall, MIT licensed.
+# Trimmed to the subset dyndnsd uses (meters + registry + reporters).
+
+require 'metriks/meter'
+
+module Metriks
+  # Public: A collection of metrics
+  class Registry
+    # Public: The default registry for the process.
+    #
+    # Returns the default Registry for the process.
+    def self.default
+      @default ||= new
+    end
+
+    # Public: Initializes a new Registry.
+    def initialize
+      @mutex = Mutex.new
+      @metrics = {}
+    end
+
+    # Public: Clear all of the metrics in the Registry. This ensures all
+    # metrics that have been added are stopped.
+    #
+    # Returns nothing.
+    def clear
+      @mutex.synchronize do
+        @metrics.each do |key, metric|
+          metric.stop if metric.respond_to?(:stop)
+        end
+
+        @metrics = {}
+      end
+    end
+
+    # Public: Clear all of the metrics in the Registry. This has the same
+    # effect as calling #clear.
+    #
+    # Returns nothing.
+    def stop
+      clear
+    end
+
+    # Public: Iterate over all of the counters.
+    #
+    # Examples
+    #
+    #   registry.each do |name, metric|
+    #     puts name
+    #   end
+    #
+    # Returns nothing.
+    def each(&block)
+      metrics = @mutex.synchronize do
+        @metrics.dup
+      end
+
+      metrics.each(&block)
+    end
+
+    # Public: Fetch or create a new meter metric. Meters are a counter that
+    # tracks throughput along with the count.
+    #
+    # name - The String name of the metric to define or fetch
+    #
+    # Examples
+    #
+    #   registry.meter('resque.calls')
+    #
+    # Returns the Metriks::Meter identified by the name.
+    def meter(name)
+      add_or_get(name, Metriks::Meter)
+    end
+
+    # Public: Fetch an existing metric.
+    #
+    # name - The String name of the metric to fetch
+    #
+    # Examples
+    #
+    #   registry.get('rack.utilization')
+    #
+    # Returns the metric or nil.
+    def get(name)
+      @mutex.synchronize do
+        @metrics[name]
+      end
+    end
+
+    # Public: Add a new metric.
+    #
+    # name - The String name of the metric to add
+    # metric - The metric instance to add
+    #
+    # Examples
+    #
+    #   registry.add('method.calls', Metriks::Counter.new)
+    #
+    # Returns nothing.
+    # Raises RuntimeError if the metric name is already defined
+    def add(name, metric)
+      @mutex.synchronize do
+        if @metrics[name]
+          raise "Metric '#{name}' already defined"
+        else
+          @metrics[name] = metric
+        end
+      end
+    end
+
+    protected
+    def add_or_get(name, klass, &create_metric)
+      @mutex.synchronize do
+        if metric = @metrics[name]
+          if !metric.is_a?(klass)
+            raise "Metric already defined as '#{metric.class}'"
+          else
+            return metric
+          end
+        else
+          @metrics[name] = create_metric ? create_metric.call : klass.new
+        end
+      end
+    end
+  end
+end