From fbf59bdbea63efd34ccc144e648467d2f52e7345 Mon Sep 17 00:00:00 2001
From: drbrain <drbrain@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Sat, 10 Nov 2007 07:48:56 +0000
Subject: Import RubyGems trunk revision 1493.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@13862 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 lib/rubygems/old_format.rb | 148 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 148 insertions(+)
 create mode 100644 lib/rubygems/old_format.rb

(limited to 'lib/rubygems/old_format.rb')

diff --git a/lib/rubygems/old_format.rb b/lib/rubygems/old_format.rb
new file mode 100644
index 0000000000..ef5d621f52
--- /dev/null
+++ b/lib/rubygems/old_format.rb
@@ -0,0 +1,148 @@
+#--
+# Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
+# All rights reserved.
+# See LICENSE.txt for permissions.
+#++
+
+require 'fileutils'
+require 'yaml'
+require 'zlib'
+
+module Gem
+
+  ##
+  # The format class knows the guts of the RubyGem .gem file format
+  # and provides the capability to read gem files
+  #
+  class OldFormat
+    attr_accessor :spec, :file_entries, :gem_path
+  
+    ##
+    # Constructs an instance of a Format object, representing the gem's
+    # data structure.
+    #
+    # gem:: [String] The file name of the gem
+    #
+    def initialize(gem_path)
+      @gem_path = gem_path
+    end
+    
+    ##
+    # Reads the named gem file and returns a Format object, representing 
+    # the data from the gem file
+    #
+    # file_path:: [String] Path to the gem file
+    #
+    def self.from_file_by_path(file_path)
+      unless File.exist?(file_path)
+        raise Gem::Exception, "Cannot load gem file [#{file_path}]"
+      end
+      File.open(file_path, 'rb') do |file|
+        from_io(file, file_path)
+      end
+    end
+
+    ##
+    # Reads a gem from an io stream and returns a Format object, representing
+    # the data from the gem file
+    #
+    # io:: [IO] Stream from which to read the gem
+    #
+    def self.from_io(io, gem_path="(io)")
+      format = self.new(gem_path)
+      skip_ruby(io)
+      format.spec = read_spec(io)
+      format.file_entries = []
+      read_files_from_gem(io) do |entry, file_data|
+        format.file_entries << [entry, file_data]
+      end
+      format
+    end
+    
+    private 
+    ##
+    # Skips the Ruby self-install header.  After calling this method, the
+    # IO index will be set after the Ruby code.
+    #
+    # file:: [IO] The IO to process (skip the Ruby code)
+    #
+    def self.skip_ruby(file)
+      end_seen = false
+      loop {
+        line = file.gets
+        if(line == nil || line.chomp == "__END__") then
+          end_seen = true
+          break
+        end
+      }
+     if(end_seen == false) then
+       raise Gem::Exception.new("Failed to find end of ruby script while reading gem")
+     end
+    end
+     
+    ##
+    # Reads the specification YAML from the supplied IO and constructs
+    # a Gem::Specification from it.  After calling this method, the
+    # IO index will be set after the specification header.
+    #
+    # file:: [IO] The IO to process
+    #
+    def self.read_spec(file)
+      yaml = ''
+      begin
+        read_until_dashes(file) do |line|
+          yaml << line
+        end
+        Specification.from_yaml(yaml)
+      rescue YAML::Error => e
+        raise Gem::Exception.new("Failed to parse gem specification out of gem file")
+      rescue ArgumentError => e
+        raise Gem::Exception.new("Failed to parse gem specification out of gem file")
+      end
+    end
+    
+    ##
+    # Reads lines from the supplied IO until a end-of-yaml (---) is
+    # reached
+    #
+    # file:: [IO] The IO to process
+    # block:: [String] The read line
+    #
+    def self.read_until_dashes(file)
+      while((line = file.gets) && line.chomp.strip != "---") do
+        yield line
+      end
+    end
+
+
+    ##
+    # Reads the embedded file data from a gem file, yielding an entry
+    # containing metadata about the file and the file contents themselves
+    # for each file that's archived in the gem.
+    # NOTE: Many of these methods should be extracted into some kind of
+    # Gem file read/writer
+    #
+    # gem_file:: [IO] The IO to process
+    #
+    def self.read_files_from_gem(gem_file)
+      errstr = "Error reading files from gem"
+      header_yaml = ''
+      begin
+        self.read_until_dashes(gem_file) do |line|
+          header_yaml << line
+        end
+        header = YAML.load(header_yaml)
+        raise Gem::Exception.new(errstr) unless header
+        header.each do |entry|
+          file_data = ''
+          self.read_until_dashes(gem_file) do |line|
+            file_data << line
+          end
+          yield [entry, Zlib::Inflate.inflate(file_data.strip.unpack("m")[0])]
+        end
+      rescue Exception,Zlib::DataError => e
+        raise Gem::Exception.new(errstr)
+      end
+    end
+  end
+end
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