Add adapter for HTTP gem

Gemfile

@@ -20,6 +20,7 @@ group :test do
   gem "mysql2", "~> 0.5"
   gem "trilogy", "~> 2.4"
   gem "activerecord", github: "rails/rails", branch: "main"
+  gem "http", "~> 5.2.0"
   gem "hiredis", "~> 0.6"
   # NOTE: v0.12.0 required for ruby 3.2.0. https://github.com/redis-rb/redis-client/issues/58
   gem "hiredis-client", ">= 0.12.0"

lib/semian/http.rb

@@ -0,0 +1,114 @@
+# frozen_string_literal: true
+
+require "semian/adapter"
+require "http"
+
+module HTTP
+  HTTP::Error.include(Semian::AdapterError)
+
+  class SemianError < HTTP::Error
+    def initialize(semian_identifier, *args)
+      super(*args)
+      @semian_identifier = semian_identifier
+    end
+  end
+
+  ResourceBusyError = Class.new(SemianError)
+  CircuitOpenError = Class.new(SemianError)
+end
+
+module Semian
+  module HTTP
+    include Semian::Adapter
+
+    ResourceBusyError = ::HTTP::ResourceBusyError
+    CircuitOpenError = ::HTTP::CircuitOpenError
+
+    class SemianConfigurationChangedError < RuntimeError
+      def initialize(msg = "Cannot re-initialize semian_configuration")
+        super
+      end
+    end
+
+    def semian_identifier
+      "http_gem_#{raw_semian_options[:name]}"
+    end
+
+    DEFAULT_ERRORS = [
+      ::HTTP::Error,
+    ].freeze
+
+    module ClassMethods
+      def new(*args, semian: true)
+        http = super(*args)
+        http.instance_variable_set(:@semian_enabled, semian)
+        http
+      end
+    end
+
+    class << self
+      attr_accessor :exceptions
+      attr_reader :semian_configuration
+
+      def semian_configuration=(configuration)
+        raise Semian::HTTP::SemianConfigurationChangedError unless @semian_configuration.nil?
+
+        @semian_configuration = configuration
+      end
+
+      def retrieve_semian_configuration(host, port)
+        @semian_configuration.call(host, port) if @semian_configuration.respond_to?(:call)
+      end
+
+      def reset_exceptions
+        self.exceptions = Semian::HTTP::DEFAULT_ERRORS.dup
+      end
+    end
+
+    Semian::HTTP.reset_exceptions
+
+    def raw_semian_options
+      @raw_semian_options
+    end
+
+    def resource_exceptions
+      Semian::HTTP.exceptions
+    end
+
+    def disabled?
+      raw_semian_options.nil? || @semian_enabled == false
+    end
+
+    def perform(request, _options)
+      address = request.uri.host
+      port = request.uri.port
+
+      @raw_semian_options = Semian::HTTP.retrieve_semian_configuration(address, port)&.dup
+
+      return super if disabled?
+
+      acquire_semian_resource(adapter: :http_gem, scope: :query) do
+        handle_error_responses(super)
+      end
+    ensure
+      @raw_semian_options = nil
+    end
+
+    private
+
+    def handle_error_responses(result)
+      if @raw_semian_options.fetch(:open_circuit_server_errors, false) && error_result?(result)
+        semian_resource.mark_failed(::HTTP::Error.new("Server returned status #{result&.status}"))
+      end
+
+      result
+    end
+
+    def error_result?(result)
+      result.nil? || result.status.nil? || (500..599).cover?(result.status)
+    end
+  end
+end
+
+HTTP::Client.prepend(Semian::HTTP)
+HTTP::Client.singleton_class.prepend(Semian::HTTP::ClassMethods)