[ruby/rubygems] Allow to specify the number of make jobs when installing gems:

- Added a new `-j` option to `gem install` and `gem update`.
  This option allows to specify the number of jobs we pass to `make`
  when compiling gem with native extensions.

  By default its the number of processors, but users may want a way
  to control this.

  You can use it like so: `gem install json -j8`

ruby/rubygems@67aad88ca6

Author: Edouard-chin

lib/rubygems/dependency_installer.rb

@@ -83,6 +83,7 @@ def initialize(options = {})
     @user_install        = options[:user_install]
     @wrappers            = options[:wrappers]
     @build_args          = options[:build_args]
+    @build_jobs          = options[:build_jobs]
     @build_docs_in_background = options[:build_docs_in_background]
     @dir_mode = options[:dir_mode]
     @data_mode = options[:data_mode]
@@ -154,6 +155,7 @@ def install(dep_or_name, version = Gem::Requirement.default)
     options = {
       bin_dir: @bin_dir,
       build_args: @build_args,
+      build_jobs: @build_jobs,
       document: @document,
       env_shebang: @env_shebang,
       force: @force,

lib/rubygems/install_update_options.rb

@@ -31,6 +31,15 @@ def add_install_update_options
       options[:bin_dir] = File.expand_path(value)
     end
 
+    add_option(:"Install/Update", "-j", "--build-jobs VALUE", Integer,
+               "Specify the number of jobs to pass to `make` when installing",
+               "gems with native extensions.",
+               "Defaults to the number of processors.",
+               "This option is ignored on the mswin platform or",
+               "if the MAKEFLAGS environment variable is set.") do |value, options|
+      options[:build_jobs] = value
+    end
+
     add_option(:"Install/Update", "--document [TYPES]", Array,
                "Generate documentation for installed gems",
                "List the documentation types you wish to",

test/rubygems/test_gem_commands_install_command.rb

@@ -1584,6 +1584,34 @@ def test_suggest_update_if_enabled
     end
   end
 
+  def test_pass_down_the_job_option_to_make
+    gemspec = nil
+
+    spec_fetcher do |fetcher|
+      fetcher.gem "a", 2 do |spec|
+        gemspec = spec
+
+        extconf_path = "#{spec.gem_dir}/extconf.rb"
+
+        write_file(extconf_path) do |io|
+          io.puts "require 'mkmf'"
+          io.puts "create_makefile '#{spec.name}'"
+        end
+
+        spec.extensions = "extconf.rb"
+      end
+    end
+
+    use_ui @ui do
+      assert_raise Gem::MockGemUi::SystemExitException, @ui.error do
+        @cmd.invoke "a", "-j4"
+      end
+    end
+
+    gem_make_out = File.read(File.join(gemspec.extension_dir, "gem_make.out"))
+    assert_includes(gem_make_out, "make -j4")
+  end
+
   def test_execute_bindir_with_nonexistent_parent_dirs
     spec_fetcher do |fetcher|
       fetcher.gem "a", 2 do |s|

test/rubygems/test_gem_commands_update_command.rb

@@ -696,6 +696,34 @@ def test_fetch_remote_gems_prerelease
     assert_equal expected, @cmd.fetch_remote_gems(specs["a-1"])
   end
 
+  def test_pass_down_the_job_option_to_make
+    gemspec = nil
+
+    spec_fetcher do |fetcher|
+      fetcher.download "a", 3 do |spec|
+        gemspec = spec
+
+        extconf_path = "#{spec.gem_dir}/extconf.rb"
+
+        write_file(extconf_path) do |io|
+          io.puts "require 'mkmf'"
+          io.puts "create_makefile '#{spec.name}'"
+        end
+
+        spec.extensions = "extconf.rb"
+      end
+
+      fetcher.gem "a", 2
+    end
+
+    use_ui @ui do
+      @cmd.invoke("a", "-j2")
+    end
+
+    gem_make_out = File.read(File.join(gemspec.extension_dir, "gem_make.out"))
+    assert_includes(gem_make_out, "make -j2")
+  end
+
   def test_handle_options_system
     @cmd.handle_options %w[--system]
 

test/rubygems/test_gem_install_update_options.rb

@@ -202,4 +202,16 @@ def test_minimal_deps
 
     assert_equal true, @cmd.options[:minimal_deps]
   end
+
+  def test_build_jobs_short_version
+    @cmd.handle_options %w[-j 4]
+
+    assert_equal 4, @cmd.options[:build_jobs]
+  end
+
+  def test_build_jobs_long_version
+    @cmd.handle_options %w[--build-jobs 4]
+
+    assert_equal 4, @cmd.options[:build_jobs]
+  end
 end