Optimize Grape::Path -> Reduce Hash Allocation (#2513)

* Grape::Path is now exposing only path and suffix
Last parameter is now double splatted

* Remove double splat operator

* Optimize default path settings
Use const static function for route match?

* Revert compile_many_routes.rb

* Add CHANGELOG.md

Author: ericproulx

CHANGELOG.md

@@ -7,6 +7,7 @@
 * [#2501](https://github.com/ruby-grape/grape/pull/2501): Remove deprecated `except` and `proc` options in values validator - [@ericproulx](https://github.com/ericproulx).
 * [#2502](https://github.com/ruby-grape/grape/pull/2502): Remove deprecation `options` in `desc` - [@ericproulx](https://github.com/ericproulx).
 * [#2512](https://github.com/ruby-grape/grape/pull/2512): Optimize hash alloc - [@ericproulx](https://github.com/ericproulx).
+* [#2513](https://github.com/ruby-grape/grape/pull/2513): Optimize Grape::Path - [@ericproulx](https://github.com/ericproulx).
 * Your contribution here.
 
 #### Fixes

lib/grape/endpoint.rb

@@ -160,12 +160,13 @@ def mount_in(router)
     end
 
     def to_routes
-      route_options = prepare_default_route_attributes
-      map_routes do |method, path|
-        path = prepare_path(path)
-        route_options[:suffix] = path.suffix
-        params = options[:route_options].merge(route_options)
-        route = Grape::Router::Route.new(method, path.path, params)
+      default_route_options = prepare_default_route_attributes
+      default_path_settings = prepare_default_path_settings
+
+      map_routes do |method, raw_path|
+        prepared_path = Path.new(raw_path, namespace, default_path_settings)
+        params = options[:route_options].present? ? options[:route_options].merge(default_route_options) : default_route_options
+        route = Grape::Router::Route.new(method, prepared_path.origin, prepared_path.suffix, params)
         route.apply(self)
       end.flatten
     end
@@ -200,11 +201,10 @@ def map_routes
       options[:method].map { |method| options[:path].map { |path| yield method, path } }
     end
 
-    def prepare_path(path)
+    def prepare_default_path_settings
       namespace_stackable_hash = inheritable_setting.namespace_stackable.to_hash
       namespace_inheritable_hash = inheritable_setting.namespace_inheritable.to_hash
-      path_settings = namespace_stackable_hash.merge!(namespace_inheritable_hash)
-      Path.new(path, namespace, path_settings)
+      namespace_stackable_hash.merge!(namespace_inheritable_hash)
     end
 
     def namespace

lib/grape/path.rb

@@ -3,65 +3,66 @@
 module Grape
   # Represents a path to an endpoint.
   class Path
-    attr_reader :raw_path, :namespace, :settings
+    DEFAULT_FORMAT_SEGMENT = '(/.:format)'
+    NO_VERSIONING_WITH_VALID_PATH_FORMAT_SEGMENT = '(.:format)'
+    VERSION_SEGMENT = ':version'
 
-    def initialize(raw_path, namespace, settings)
-      @raw_path = raw_path
-      @namespace = namespace
-      @settings = settings
-    end
+    attr_reader :origin, :suffix
 
-    def mount_path
-      settings[:mount_path]
+    def initialize(raw_path, raw_namespace, settings)
+      @origin = PartsCache[build_parts(raw_path, raw_namespace, settings)]
+      @suffix = build_suffix(raw_path, raw_namespace, settings)
     end
 
-    def root_prefix
-      settings[:root_prefix]
+    def to_s
+      "#{origin}#{suffix}"
     end
 
-    def uses_specific_format?
-      return false unless settings.key?(:format) && settings.key?(:content_types)
+    private
 
-      settings[:format] && Array(settings[:content_types]).size == 1
+    def build_suffix(raw_path, raw_namespace, settings)
+      if uses_specific_format?(settings)
+        "(.#{settings[:format]})"
+      elsif !uses_path_versioning?(settings) || (valid_part?(raw_namespace) || valid_part?(raw_path))
+        NO_VERSIONING_WITH_VALID_PATH_FORMAT_SEGMENT
+      else
+        DEFAULT_FORMAT_SEGMENT
+      end
     end
 
-    def uses_path_versioning?
-      return false unless settings.key?(:version) && settings[:version_options]&.key?(:using)
-
-      settings[:version] && settings[:version_options][:using] == :path
+    def build_parts(raw_path, raw_namespace, settings)
+      [].tap do |parts|
+        add_part(parts, settings[:mount_path])
+        add_part(parts, settings[:root_prefix])
+        parts << VERSION_SEGMENT if uses_path_versioning?(settings)
+        add_part(parts, raw_namespace)
+        add_part(parts, raw_path)
+      end
     end
 
-    def namespace?
-      namespace&.match?(/^\S/) && not_slash?(namespace)
+    def add_part(parts, value)
+      parts << value if value && not_slash?(value)
     end
 
-    def path?
-      raw_path&.match?(/^\S/) && not_slash?(raw_path)
+    def not_slash?(value)
+      value != '/'
     end
 
-    def suffix
-      if uses_specific_format?
-        "(.#{settings[:format]})"
-      elsif !uses_path_versioning? || (namespace? || path?)
-        '(.:format)'
-      else
-        '(/.:format)'
-      end
-    end
+    def uses_specific_format?(settings)
+      return false unless settings.key?(:format) && settings.key?(:content_types)
 
-    def path
-      PartsCache[parts]
+      settings[:format] && Array(settings[:content_types]).size == 1
     end
 
-    def path_with_suffix
-      "#{path}#{suffix}"
-    end
+    def uses_path_versioning?(settings)
+      return false unless settings.key?(:version) && settings[:version_options]&.key?(:using)
 
-    def to_s
-      path_with_suffix
+      settings[:version] && settings[:version_options][:using] == :path
     end
 
-    private
+    def valid_part?(part)
+      part&.match?(/^\S/) && not_slash?(part)
+    end
 
     class PartsCache < Grape::Util::Cache
       def initialize
@@ -71,23 +72,5 @@ def initialize
         end
       end
     end
-
-    def parts
-      [].tap do |parts|
-        add_part(parts, mount_path)
-        add_part(parts, root_prefix)
-        parts << ':version' if uses_path_versioning?
-        add_part(parts, namespace)
-        add_part(parts, raw_path)
-      end
-    end
-
-    def add_part(parts, value)
-      parts << value if value && not_slash?(value)
-    end
-
-    def not_slash?(value)
-      value != '/'
-    end
   end
 end

lib/grape/router/pattern.rb

@@ -9,14 +9,14 @@ class Pattern
 
       attr_reader :origin, :path, :pattern, :to_regexp
 
-      def_delegators :pattern, :named_captures, :params
+      def_delegators :pattern, :params
       def_delegators :to_regexp, :===
       alias match? ===
 
-      def initialize(pattern, options)
-        @origin = pattern
-        @path = build_path(pattern, options)
-        @pattern = build_pattern(@path, options)
+      def initialize(origin, suffix, options)
+        @origin = origin
+        @path = build_path(origin, options[:anchor], suffix)
+        @pattern = build_pattern(@path, options[:params], options[:format], options[:version], options[:requirements])
         @to_regexp = @pattern.to_regexp
       end
 
@@ -28,33 +28,34 @@ def captures_default
 
       private
 
-      def build_pattern(path, options)
+      def build_pattern(path, params, format, version, requirements)
         Mustermann::Grape.new(
           path,
           uri_decode: true,
-          params: options[:params],
-          capture: extract_capture(options)
+          params: params,
+          capture: extract_capture(format, version, requirements)
         )
       end
 
-      def build_path(pattern, options)
-        PatternCache[[build_path_from_pattern(pattern, options), options[:suffix]]]
+      def build_path(pattern, anchor, suffix)
+        PatternCache[[build_path_from_pattern(pattern, anchor), suffix]]
       end
 
-      def extract_capture(options)
-        sliced_options = options
-                         .slice(:format, :version)
-                         .delete_if { |_k, v| v.blank? }
-                         .transform_values { |v| Array.wrap(v).map(&:to_s) }
-        return sliced_options if options[:requirements].blank?
+      def extract_capture(format, version, requirements)
+        capture = {}.tap do |h|
+          h[:format] = map_str(format) if format.present?
+          h[:version] = map_str(version) if version.present?
+        end
+
+        return capture if requirements.blank?
 
-        options[:requirements].merge(sliced_options)
+        requirements.merge(capture)
       end
 
-      def build_path_from_pattern(pattern, options)
+      def build_path_from_pattern(pattern, anchor)
         if pattern.end_with?('*path')
           pattern.dup.insert(pattern.rindex('/') + 1, '?')
-        elsif options[:anchor]
+        elsif anchor
           pattern
         elsif pattern.end_with?('/')
           "#{pattern}?*path"
@@ -63,6 +64,10 @@ def build_path_from_pattern(pattern, options)
         end
       end
 
+      def map_str(value)
+        Array.wrap(value).map(&:to_s)
+      end
+
       class PatternCache < Grape::Util::Cache
         def initialize
           super

lib/grape/router/route.rb

@@ -5,13 +5,17 @@ class Router
     class Route < BaseRoute
       extend Forwardable
 
+      FORWARD_MATCH_METHOD = ->(input, pattern) { input.start_with?(pattern.origin) }
+      NON_FORWARD_MATCH_METHOD = ->(input, pattern) { pattern.match?(input) }
+
       attr_reader :app, :request_method
 
       def_delegators :pattern, :path, :origin
 
-      def initialize(method, pattern, options)
+      def initialize(method, origin, path, options)
         @request_method = upcase_method(method)
-        @pattern = Grape::Router::Pattern.new(pattern, options)
+        @pattern = Grape::Router::Pattern.new(origin, path, options)
+        @match_function = options[:forward_match] ? FORWARD_MATCH_METHOD : NON_FORWARD_MATCH_METHOD
         super(options)
       end
 
@@ -31,7 +35,7 @@ def apply(app)
       def match?(input)
         return false if input.blank?
 
-        options[:forward_match] ? input.start_with?(pattern.origin) : pattern.match?(input)
+        @match_function.call(input, pattern)
       end
 
       def params(input = nil)
@@ -46,7 +50,7 @@ def params(input = nil)
       private
 
       def params_without_input
-        pattern.captures_default.merge(attributes.params)
+        @params_without_input ||= pattern.captures_default.merge(attributes.params)
       end
 
       def upcase_method(method)