summaryrefslogtreecommitdiffstats
path: root/gem_prelude.rb
blob: ec9f1f4f33471f2328b7293d1cc2dcc90558ce0d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
# depends on: array.rb dir.rb env.rb file.rb hash.rb module.rb regexp.rb

# empty gem_prelude.rb
#
# p defined?(Gem)

if defined?(Gem) then

  module Kernel

    def gem(gem_name, *version_requirements)
      Gem.push_gem_version_on_load_path(gem_name, *version_requirements)
    end

  end

  module Gem

    ConfigMap = {
      :sitedir => RbConfig::CONFIG["sitedir"],
      :ruby_version => RbConfig::CONFIG["ruby_version"],
      :libdir => RbConfig::CONFIG["libdir"],
      :sitelibdir => RbConfig::CONFIG["sitelibdir"],
      :arch => RbConfig::CONFIG["arch"],
      :bindir => RbConfig::CONFIG["bindir"],
      :EXEEXT => RbConfig::CONFIG["EXEEXT"],
      :RUBY_SO_NAME => RbConfig::CONFIG["RUBY_SO_NAME"],
      :ruby_install_name => RbConfig::CONFIG["ruby_install_name"]
    }

    class << self

      def default_dir
        if defined? RUBY_FRAMEWORK_VERSION
          return File.join(File.dirname(ConfigMap[:sitedir]), "Gems")
        else
          File.join(ConfigMap[:libdir], 'ruby', 'gems', ConfigMap[:ruby_version])
        end
      end

      def dir
        @gem_home ||= nil
        set_home(ENV['GEM_HOME'] || default_dir) unless @gem_home
        @gem_home
      end

      def path
        @gem_path ||= nil
        unless @gem_path
          paths = [ENV['GEM_PATH']]
          paths << APPLE_GEM_HOME if defined? APPLE_GEM_HOME
          set_paths(paths.compact.join(File::PATH_SEPARATOR))
        end
        @gem_path
      end

      # Set the Gem home directory (as reported by +dir+).
      def set_home(home)
        @gem_home = home
        ensure_gem_subdirectories(@gem_home)
      end

      def set_paths(gpaths)
        if gpaths
          @gem_path = gpaths.split(File::PATH_SEPARATOR)
          @gem_path << Gem.dir
        else
          @gem_path = [Gem.dir]
        end
        @gem_path.uniq!
        @gem_path.each do |gp| ensure_gem_subdirectories(gp) end
      end

      def ensure_gem_subdirectories(path)
      end

    end

    module QuickLoader

      class << self
        def load_full_rubygems_library
          class << Gem
            Gem.methods(false).each do |method_name|
              undef_method method_name
            end
          end

          Kernel.module_eval do
            undef_method :gem if method_defined? :gem
          end

          $".delete File.join(Gem::ConfigMap[:libdir], 'ruby',
                              Gem::ConfigMap[:ruby_version], 'rubygems.rb')

          require 'rubygems'
        end
      end

      GemPaths = {}
      GemVersions = {}

      def push_gem_version_on_load_path(gem_name, *version_requirements)
        if version_requirements.empty?
          unless GemPaths.has_key?(gem_name)
            raise LoadError.new("Could not find RubyGem #{gem_name} (>= 0)\n") 
          end

          # highest version gems already active
          return false
        else
          if version_requirements.length > 1
            QuickLoader.load_full_rubygems_library
            return gem(gem_name, *version_requirements)
          end

          requirement, version = version_requirements[0].split
          requirement.strip!

          if requirement == ">" || requirement == ">="
            if (GemVersions[gem_name] <=> Gem.calculate_integers_for_gem_version(version)) >= 0
              return false 
            end
          elsif requirement == "~>"
            loaded_version = GemVersions[gem_name]
            required_version = Gem.calculate_integers_for_gem_version(version)
            if loaded_version && (loaded_version[0] == required_version[0])
              return false
            end
          end

          QuickLoader.load_full_rubygems_library
          gem(gem_name, *version_requirements)
        end
      end

      def calculate_integers_for_gem_version(gem_version)
        numbers = gem_version.split(".").collect {|n| n.to_i}
        numbers.pop while numbers.last == 0
        numbers << 0 if numbers.empty?
        numbers
      end

      def push_all_highest_version_gems_on_load_path
        Gem.path.each do |path|
          gems_directory = File.join(path, "gems")
          if File.exist?(gems_directory)
            Dir.entries(gems_directory).each do |gem_directory_name|
              next if gem_directory_name == "." || gem_directory_name == ".."
              dash = gem_directory_name.rindex("-")
              next if dash.nil?
              gem_name = gem_directory_name[0...dash]
              current_version = GemVersions[gem_name]
              new_version = calculate_integers_for_gem_version(gem_directory_name[dash+1..-1])
              if current_version
                if (current_version <=> new_version) == -1
                  GemVersions[gem_name] = new_version
                  GemPaths[gem_name] = File.join(gems_directory, gem_directory_name)
                end
              else
                GemVersions[gem_name] = new_version
                GemPaths[gem_name] = File.join(gems_directory, gem_directory_name)
              end
            end
          end
        end

        require_paths = []

        GemPaths.values.each do |path|
          if File.exist?(File.join(path, ".require_paths"))
            require_paths.concat(File.read(File.join(path, ".require_paths")).split.map {|require_path| File.join(path, require_path)})
          else
            require_paths << File.join(path, "bin") if File.exist?(File.join(path, "bin"))
            require_paths << File.join(path, "lib") if File.exist?(File.join(path, "lib"))
          end
        end

        # "tag" the first require_path inserted into the $LOAD_PATH to enable
        # indexing correctly with rubygems proper when it inserts an explicitly
        # gem version
        unless require_paths.empty?
          require_paths.first.instance_variable_set(:@gem_prelude_index, true)
        end
        # gem directories must come after -I and ENV['RUBYLIB']
        $:[$:.index(ConfigMap[:sitelibdir]),0] = require_paths
      end

      def const_missing(constant)
        QuickLoader.load_full_rubygems_library
        if Gem.const_defined?(constant)
          Gem.const_get(constant)
        else
          super
        end
      end

      def method_missing(method, *args, &block)
        QuickLoader.load_full_rubygems_library
        super unless Gem.respond_to?(method)
        Gem.send(method, *args, &block)
      end
    end

    extend QuickLoader

  end

  begin
    Gem.push_all_highest_version_gems_on_load_path
    $" << File.join(Gem::ConfigMap[:libdir], "ruby",
                    Gem::ConfigMap[:ruby_version], "rubygems.rb")
  rescue Exception => e
    puts "Error loading gem paths on load path in gem_prelude"
    puts e
    puts e.backtrace.join("\n")
  end

end