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authorJari Vetoniemi <jari.vetoniemi@indooratlas.com>2020-03-16 18:49:26 +0900
committerJari Vetoniemi <jari.vetoniemi@indooratlas.com>2020-03-30 00:39:06 +0900
commitfcbf63e62c627deae76c1b8cb8c0876c536ed811 (patch)
tree64cb17de3f41a2b6fef2368028fbd00349946994 /jni/ruby/lib/rubygems/package/tar_reader.rb
Fresh start
Diffstat (limited to 'jni/ruby/lib/rubygems/package/tar_reader.rb')
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diff --git a/jni/ruby/lib/rubygems/package/tar_reader.rb b/jni/ruby/lib/rubygems/package/tar_reader.rb
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+# -*- coding: utf-8 -*-
+#--
+# Copyright (C) 2004 Mauricio Julio Fernández Pradier
+# See LICENSE.txt for additional licensing information.
+#++
+
+##
+# TarReader reads tar files and allows iteration over their items
+
+class Gem::Package::TarReader
+
+ include Enumerable
+
+ ##
+ # Raised if the tar IO is not seekable
+
+ class UnexpectedEOF < StandardError; end
+
+ ##
+ # Creates a new TarReader on +io+ and yields it to the block, if given.
+
+ def self.new(io)
+ reader = super
+
+ return reader unless block_given?
+
+ begin
+ yield reader
+ ensure
+ reader.close
+ end
+
+ nil
+ end
+
+ ##
+ # Creates a new tar file reader on +io+ which needs to respond to #pos,
+ # #eof?, #read, #getc and #pos=
+
+ def initialize(io)
+ @io = io
+ @init_pos = io.pos
+ end
+
+ ##
+ # Close the tar file
+
+ def close
+ end
+
+ ##
+ # Iterates over files in the tarball yielding each entry
+
+ def each
+ return enum_for __method__ unless block_given?
+
+ until @io.eof? do
+ 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
+ pending = size - entry.bytes_read
+
+ begin
+ # avoid reading...
+ @io.seek pending, IO::SEEK_CUR
+ pending = 0
+ rescue Errno::EINVAL, NameError
+ while pending > 0 do
+ bytes_read = @io.read([pending, 4096].min).size
+ raise UnexpectedEOF if @io.eof?
+ pending -= bytes_read
+ 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
+
+ ##
+ # Seeks through the tar file until it finds the +entry+ with +name+ and
+ # yields it. Rewinds the tar file to the beginning when the block
+ # terminates.
+
+ def seek name # :yields: entry
+ found = find do |entry|
+ entry.full_name == name
+ end
+
+ return unless found
+
+ return yield found
+ ensure
+ rewind
+ end
+
+end
+
+require 'rubygems/package/tar_reader/entry'
+