aboutsummaryrefslogtreecommitdiffstats
path: root/railties/lib/rails/gem_dependency.rb
blob: 3062a7710457511c34ab5f69930e2e62ea502054 (plain) (blame)
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
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
require 'rails/vendor_gem_source_index'

module Gem
  def self.source_index=(index)
    @@source_index = index
  end
end

module Rails
  class GemDependency < Gem::Dependency
    attr_accessor :lib, :source, :dep

    def self.unpacked_path
      @unpacked_path ||= File.join(RAILS_ROOT, 'vendor', 'gems')
    end

    @@framework_gems = {}

    def self.add_frozen_gem_path
      @@paths_loaded ||= begin
        source_index = Rails::VendorGemSourceIndex.new(Gem.source_index)
        Gem.clear_paths
        Gem.source_index = source_index
        # loaded before us - we can't change them, so mark them
        Gem.loaded_specs.each do |name, spec|
          @@framework_gems[name] = spec
        end
        true
      end
    end

    def initialize(name, options = {})
      require 'rubygems' unless Object.const_defined?(:Gem)

      if options[:requirement]
        req = options[:requirement]
      elsif options[:version]
        req = Gem::Requirement.create(options[:version])
      else
        req = Gem::Requirement.default
      end

      @lib      = options[:lib]
      @source   = options[:source]
      @loaded   = @frozen = @load_paths_added = false

      super(name, req)
    end

    def add_load_paths
      self.class.add_frozen_gem_path
      return if @loaded || @load_paths_added
      if framework_gem?
        @load_paths_added = @loaded = @frozen = true
        return
      end
      gem self
      @spec = Gem.loaded_specs[name]
      @frozen = @spec.loaded_from.include?(self.class.unpacked_path) if @spec
      @load_paths_added = true
    rescue Gem::LoadError
    end

    def dependencies
      return [] if framework_gem?
      return [] unless installed?
      specification.dependencies.reject do |dependency|
        dependency.type == :development
      end.map do |dependency|
        GemDependency.new(dependency.name, :requirement => dependency.version_requirements)
      end
    end

    def specification
      # code repeated from Gem.activate. Find a matching spec, or the currently loaded version.
      # error out if loaded version and requested version are incompatible.
      @spec ||= begin
        matches = Gem.source_index.search(self)
        matches << @@framework_gems[name] if framework_gem?
        if Gem.loaded_specs[name] then
          # This gem is already loaded.  If the currently loaded gem is not in the
          # list of candidate gems, then we have a version conflict.
          existing_spec = Gem.loaded_specs[name]
          unless matches.any? { |spec| spec.version == existing_spec.version } then
            raise Gem::Exception,
                  "can't activate #{@dep}, already activated #{existing_spec.full_name}"
          end
          # we're stuck with it, so change to match
          version_requirements = Gem::Requirement.create("=#{existing_spec.version}")
          existing_spec
        else
          # new load
          matches.last
        end
      end
    end

    def requirement
      r = version_requirements
      (r == Gem::Requirement.default) ? nil : r
    end

    def built?
      # TODO: If Rubygems ever gives us a way to detect this, we should use it
      false
    end

    def framework_gem?
      @@framework_gems.has_key?(name)
    end

    def frozen?
      @frozen ||= vendor_rails? || vendor_gem?
    end

    def installed?
      Gem.loaded_specs.keys.include?(name)
    end

    def load_paths_added?
      # always try to add load paths - even if a gem is loaded, it may not
      # be a compatible version (ie random_gem 0.4 is loaded and a later spec
      # needs >= 0.5 - gem 'random_gem' will catch this and error out)
      @load_paths_added
    end

    def loaded?
      @loaded ||= begin
        if vendor_rails?
          true
        elsif specification.nil?
          false
        else
          # check if the gem is loaded by inspecting $"
          # specification.files lists all the files contained in the gem
          gem_files = specification.files
          # select only the files contained in require_paths - typically in bin and lib
          require_paths_regexp = Regexp.new("^(#{specification.require_paths*'|'})/")
          gem_lib_files = gem_files.select { |f| require_paths_regexp.match(f) }
          # chop the leading directory off - a typical file might be in
          # lib/gem_name/file_name.rb, but it will be 'require'd as gem_name/file_name.rb
          gem_lib_files.map! { |f| f.split('/', 2)[1] }
          # if any of the files from the above list appear in $", the gem is assumed to
          # have been loaded
          !(gem_lib_files & $").empty?
        end
      end
    end

    def vendor_rails?
      Gem.loaded_specs.has_key?(name) && Gem.loaded_specs[name].loaded_from.empty?
    end

    def vendor_gem?
      specification && File.exists?(unpacked_gem_directory)
    end

    def build
      require 'rails/gem_builder'
      unless built?
        return unless File.exists?(unpacked_specification_filename)
        spec = YAML::load_file(unpacked_specification_filename)
        Rails::GemBuilder.new(spec, unpacked_gem_directory).build_extensions
        puts "Built gem: '#{unpacked_gem_directory}'"
      end
      dependencies.each { |dep| dep.build }
    end

    def install
      unless installed?
        cmd = "#{gem_command} #{install_command.join(' ')}"
        puts cmd
        puts %x(#{cmd})
      end
    end

    def load
      return if @loaded || @load_paths_added == false
      require(@lib || name) unless @lib == false
      @loaded = true
    rescue LoadError
      puts $!.to_s
      $!.backtrace.each { |b| puts b }
    end

    def refresh
      Rails::VendorGemSourceIndex.silence_spec_warnings = true
      real_gems = Gem.source_index.installed_source_index
      exact_dep = Gem::Dependency.new(name, "= #{specification.version}")
      matches = real_gems.search(exact_dep)
      installed_spec = matches.first
      if frozen?
        if installed_spec
          # we have a real copy
          # get a fresh spec - matches should only have one element
          # note that there is no reliable method to check that the loaded
          # spec is the same as the copy from real_gems - Gem.activate changes
          # some of the fields
          real_spec = Gem::Specification.load(matches.first.loaded_from)
          write_specification(real_spec)
          puts "Reloaded specification for #{name} from installed gems."
        else
          # the gem isn't installed locally - write out our current specs
          write_specification(specification)
          puts "Gem #{name} not loaded locally - writing out current spec."
        end
      else
        if framework_gem?
          puts "Gem directory for #{name} not found - check if it's loading before rails."
        else
          puts "Something bad is going on - gem directory not found for #{name}."
        end
      end
    end

    def unpack(options={})
      unless frozen? || framework_gem?
        FileUtils.mkdir_p unpack_base
        Dir.chdir unpack_base do
          Gem::GemRunner.new.run(unpack_command)
        end
        # Gem.activate changes the spec - get the original
        real_spec = Gem::Specification.load(specification.loaded_from)
        write_specification(real_spec)
      end
      dependencies.each { |dep| dep.unpack } if options[:recursive]
    end

    def write_specification(spec)
      # copy the gem's specification into GEMDIR/.specification so that
      # we can access information about the gem on deployment systems
      # without having the gem installed
      File.open(unpacked_specification_filename, 'w') do |file|
        file.puts spec.to_yaml
      end
    end

    def ==(other)
      self.name == other.name && self.requirement == other.requirement
    end
    alias_method :"eql?", :"=="

    private

      def gem_command
        case RUBY_PLATFORM
          when /win32/
            'gem.bat'
          when /java/
            'jruby -S gem'
          else
            'gem'
        end
      end

      def install_command
        cmd = %w(install) << name
        cmd << "--version" << %("#{requirement.to_s}") if requirement
        cmd << "--source"  << @source  if @source
        cmd
      end

      def unpack_command
        cmd = %w(unpack) << name
        cmd << "--version" << "= "+specification.version.to_s if requirement
        cmd
      end

      def unpack_base
        Rails::GemDependency.unpacked_path
      end

      def unpacked_gem_directory
        File.join(unpack_base, specification.full_name)
      end

      def unpacked_specification_filename
        File.join(unpacked_gem_directory, '.specification')
      end

  end
end