JezK
Edit File: old_format.rb
#-- # Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others. # All rights reserved. # See LICENSE.txt for permissions. #++ require 'rubygems' ## # The format class knows the guts of the RubyGem .gem file format and provides # the capability to read gem files class Gem::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) require 'fileutils' require 'zlib' Gem.load_yaml @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 = '' read_until_dashes file do |line| yaml << line end Gem::Specification.from_yaml yaml rescue YAML::Error => e raise Gem::Exception, "Failed to parse gem specification out of gem file" rescue ArgumentError => e raise Gem::Exception, "Failed to parse gem specification out of gem file" 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, 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 Zlib::DataError raise Gem::Exception, errstr end end end