Reimplement SoftwareSpec on top of Resource

Library/Homebrew/compat/md5.rb

@@ -1,11 +1,17 @@
 class Formula
   def self.md5(val)
-    @stable ||= SoftwareSpec.new
+    @stable ||= create_spec(SoftwareSpec)
     @stable.md5(val)
   end
 end
 
 class SoftwareSpec
+  def md5(val)
+    @resource.md5(val)
+  end
+end
+
+class Resource
   def md5(val)
     @checksum = Checksum.new(:md5, val)
   end

Library/Homebrew/formula.rb

@@ -1,5 +1,4 @@
 require 'resource'
-require 'download_strategy'
 require 'dependency_collector'
 require 'formula_support'
 require 'formula_lock'
@@ -49,7 +48,7 @@ class Formula
 
     @active_spec = determine_active_spec
     validate_attributes :url, :name, :version
-    @downloader = active_spec.download_strategy.new(name, active_spec)
+    @downloader = active_spec.downloader
 
     # Combine DSL `option` and `def options`
     options.each do |opt, desc|
@@ -60,15 +59,14 @@ class Formula
     @pin = FormulaPin.new(self)
 
     @resources = self.class.resources
-    @resources.each_value do |r|
+    @resources.each_value { |r| r.owner = self }
-      r.set_owner name
-    end
   end
 
   def set_spec(name)
     spec = self.class.send(name)
     return if spec.nil?
     if block_given? && yield(spec) || !spec.url.nil?
+      spec.owner = self
       instance_variable_set("@#{name}", spec)
     end
   end
@@ -515,10 +513,7 @@ class Formula
 
   # For brew-fetch and others.
   def fetch
-    # Ensure the cache exists
+    active_spec.fetch
-    HOMEBREW_CACHE.mkpath
-    downloader.fetch
-    cached_download
   end
 
   # For FormulaInstaller.
@@ -610,11 +605,7 @@ class Formula
   private
 
   def stage
-    fetched = fetch
+    active_spec.stage do
-    verify_download_integrity(fetched) if fetched.respond_to?(:file?) and fetched.file?
-    mktemp do
-      downloader.stage
-      # Set path after the downloader changes the working folder.
       @buildpath = Pathname.pwd
       yield
       @buildpath = nil

Library/Homebrew/resource.rb

@@ -2,32 +2,35 @@ require 'download_strategy'
 require 'checksum'
 require 'version'
 
-# A Resource describes a tarball that a formula needs in addition
+# Resource is the fundamental representation of an external resource. The
-# to the formula's own download.
+# primary formula download, along with other declared resources, are instances
+# of this class.
 class Resource
   include FileUtils
 
-  # The mktmp mixin expects a name property
-  # This is the resource name
   attr_reader :name
-
   attr_reader :checksum, :mirrors, :specs, :using
 
-  def initialize name
+  # Formula name must be set after the DSL, as we have no access to the
+  # formula name before initialization of the formula
+  attr_accessor :owner
+
+  # XXX: for bottles, address this later
+  attr_writer :url, :checksum
+
+  def initialize name, url=nil, version=nil
     @name = name
-    @url = nil
+    @url = url
-    @version = nil
+    @version = version
     @mirrors = []
     @specs = {}
     @checksum = nil
     @using = nil
   end
 
-  # Formula name must be set after the DSL, as we have no access to the
+  def downloader
-  # formula name before initialization of the formula
+    download_name = name == :default ? owner.name : "#{owner.name}--#{name}"
-  def set_owner owner
+    @downloader ||= download_strategy.new(download_name, self)
-    @owner = owner
-    @downloader = download_strategy.new("#{owner}--#{name}", self)
   end
 
   # Download the resource
@@ -38,7 +41,7 @@ class Resource
     fetched = fetch
     verify_download_integrity(fetched) if fetched.respond_to?(:file?) and fetched.file?
     mktemp do
-      @downloader.stage
+      downloader.stage
       if block_given?
         yield self
       else
@@ -52,22 +55,22 @@ class Resource
   end
 
   def cached_download
-    @downloader.cached_location
+    downloader.cached_location
   end
 
   # For brew-fetch and others.
   def fetch
     # Ensure the cache exists
     HOMEBREW_CACHE.mkpath
-    @downloader.fetch
+    downloader.fetch
     cached_download
   end
 
   def verify_download_integrity fn
     fn.verify_checksum(checksum)
   rescue ChecksumMissingError
-    opoo "Cannot verify package integrity"
+    opoo "Cannot verify download integrity"
-    puts "The formula did not provide a download checksum"
+    puts "A checksum was not provided for this resource"
     puts "For your reference the SHA1 is: #{fn.sha1}"
   rescue ChecksumMismatchError => e
     e.advice = <<-EOS.undent

Library/Homebrew/software_spec.rb

@@ -1,69 +1,19 @@
-require 'download_strategy'
+require 'forwardable'
+require 'resource'
 require 'checksum'
 require 'version'
 
 class SoftwareSpec
-  attr_reader :checksum, :mirrors, :specs, :using
+  extend Forwardable
+
+  def_delegators :@resource, :owner=
+  def_delegators :@resource, :stage, :fetch
+  def_delegators :@resource, :download_strategy, :verify_download_integrity
+  def_delegators :@resource, :checksum, :mirrors, :specs, :using, :downloader
+  def_delegators :@resource, :url, :version, :mirror, *Checksum::TYPES
 
   def initialize url=nil, version=nil
-    @url = url
+    @resource = Resource.new(:default, url, version)
-    @version = version
-    @mirrors = []
-    @specs = {}
-    @checksum = nil
-    @using = nil
-  end
-
-  def download_strategy
-    @download_strategy ||= DownloadStrategyDetector.detect(url, using)
-  end
-
-  def verify_download_integrity fn
-    fn.verify_checksum(checksum)
-  rescue ChecksumMissingError
-    opoo "Cannot verify package integrity"
-    puts "The formula did not provide a download checksum"
-    puts "For your reference the SHA1 is: #{fn.sha1}"
-  rescue ChecksumMismatchError => e
-    e.advice = <<-EOS.undent
-    Archive: #{fn}
-    (To retry an incomplete download, remove the file above.)
-    EOS
-    raise e
-  end
-
-  def detect_version(val)
-    case val
-    when nil    then Version.detect(url, specs)
-    when String then Version.new(val)
-    when Hash   then Version.new_with_scheme(*val.shift)
-    else
-      raise TypeError, "version '#{val.inspect}' should be a string"
-    end
-  end
-
-  # The methods that follow are used in the block-form DSL spec methods
-  Checksum::TYPES.each do |cksum|
-    class_eval <<-EOS, __FILE__, __LINE__ + 1
-      def #{cksum}(val)
-        @checksum = Checksum.new(:#{cksum}, val)
-      end
-    EOS
-  end
-
-  def url val=nil, specs={}
-    return @url if val.nil?
-    @url = val
-    @using = specs.delete(:using)
-    @specs.merge!(specs)
-  end
-
-  def version val=nil
-    @version ||= detect_version(val)
-  end
-
-  def mirror val
-    mirrors << val
   end
 end
 
@@ -78,9 +28,10 @@ class HeadSoftwareSpec < SoftwareSpec
 end
 
 class Bottle < SoftwareSpec
-  attr_writer :url
   attr_rw :root_url, :prefix, :cellar, :revision
 
+  def_delegators :@resource, :url=
+
   def initialize
     super
     @revision = 0
@@ -102,7 +53,7 @@ class Bottle < SoftwareSpec
         end
 
         if @#{cksum}.has_key? bottle_tag
-          @checksum = @#{cksum}[bottle_tag]
+          @resource.checksum = @#{cksum}[bottle_tag]
         end
       end
     EOS