make it faster and avoid run time allocations

Author: u2

lib/grape/api.rb

@@ -95,9 +95,9 @@ def initialize
     end
 
     def call(env)
-      status, headers, body = @route_set.call(env)
-      headers.delete('X-Cascade') unless cascade?
-      [status, headers, body]
+      result = @route_set.call(env)
+      result[1].delete('X-Cascade') unless cascade?
+      result
     end
 
     # Some requests may return a HTTP 404 error if grape cannot find a matching

lib/grape/dsl/helpers.rb

@@ -64,7 +64,7 @@ module BaseHelper
         attr_accessor :api
         def params(name, &block)
           @named_params ||= {}
-          @named_params.merge! name => block
+          @named_params[name] = block
         end
 
         def api_changed(new_api)

lib/grape/dsl/parameters.rb

@@ -43,7 +43,7 @@ def requires(*attrs, &block)
         orig_attrs = attrs.clone
 
         opts = attrs.last.is_a?(Hash) ? attrs.pop.clone : {}
-        opts.merge!(presence: true)
+        opts[:presence] = true
 
         if opts[:using]
           require_required_and_optional_fields(attrs.first, opts)

lib/grape/http/request.rb

@@ -17,7 +17,7 @@ def params
     def headers
       @headers ||= env.dup.inject({}) do |h, (k, v)|
         if k.to_s.start_with? 'HTTP_'
-          k = k[5..-1].gsub('_', '-').downcase.gsub(/^.|[-_\s]./) { |x| x.upcase }
+          k = k[5..-1].tr('_', '-').downcase.gsub(/^.|[-_\s]./) { |x| x.upcase }
           h[k] = v
         end
         h

lib/grape/middleware/versioner/header.rb

@@ -68,7 +68,7 @@ def available_media_types
           available_media_types = []
 
           content_types.each do |extension, media_type|
-            versions.reverse.each do |version|
+            versions.reverse_each do |version|
               available_media_types += ["application/vnd.#{vendor}-#{version}+#{extension}", "application/vnd.#{vendor}-#{version}"]
             end
             available_media_types << "application/vnd.#{vendor}+#{extension}"