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Diffstat (limited to 'lib/rubygems/package/tar_reader.rb')
-rw-r--r-- | lib/rubygems/package/tar_reader.rb | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/lib/rubygems/package/tar_reader.rb b/lib/rubygems/package/tar_reader.rb new file mode 100644 index 0000000000..8359399207 --- /dev/null +++ b/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 + |