added tag v1_9_0_4

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/tags/v1_9_0_4@18845 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 86 insertions, 0 deletions

diff --git a/trunk/lib/rubygems/package/tar_reader.rb b/trunk/lib/rubygems/package/tar_reader.rb
new file mode 100644
index 0000000000..8359399207
--- /dev/null
+++ b/trunk/lib/rubygems/package/tar_reader.rb
@@ -0,0 +1,86 @@
+#++
+# Copyright (C) 2004 Mauricio Julio Fernández Pradier
+# See LICENSE.txt for additional licensing information.
+#--
+
+require 'rubygems/package'
+
+class Gem::Package::TarReader
+
+  include Gem::Package
+
+  class UnexpectedEOF < StandardError; end
+
+  def self.new(io)
+    reader = super
+
+    return reader unless block_given?
+
+    begin
+      yield reader
+    ensure
+      reader.close
+    end
+
+    nil
+  end
+
+  def initialize(io)
+    @io = io
+    @init_pos = io.pos
+  end
+
+  def close
+  end
+
+  def each
+    loop do
+      return if @io.eof?
+
+      header = Gem::Package::TarHeader.from @io
+      return if header.empty?
+
+      entry = Gem::Package::TarReader::Entry.new header, @io
+      size = entry.header.size
+
+      yield entry
+
+      skip = (512 - (size % 512)) % 512
+
+      if @io.respond_to? :seek then
+        # avoid reading...
+        @io.seek(size - entry.bytes_read, IO::SEEK_CUR)
+      else
+        pending = size - entry.bytes_read
+
+        while pending > 0 do
+          bread = @io.read([pending, 4096].min).size
+          raise UnexpectedEOF if @io.eof?
+          pending -= bread
+        end
+      end
+
+      @io.read skip # discard trailing zeros
+
+      # make sure nobody can use #read, #getc or #rewind anymore
+      entry.close
+    end
+  end
+
+  alias each_entry each
+
+  ##
+  # NOTE: Do not call #rewind during #each
+
+  def rewind
+    if @init_pos == 0 then
+      raise Gem::Package::NonSeekableIO unless @io.respond_to? :rewind
+      @io.rewind
+    else
+      raise Gem::Package::NonSeekableIO unless @io.respond_to? :pos=
+      @io.pos = @init_pos
+    end
+  end
+
+end
+