class Tar::Minitar::Reader
The class that reads a tar format archive from a data stream. The data stream may be sequential or random access, but certain features only work with random access data streams.
Public Class Methods
Iterates over each entry in the provided input. This wraps the common pattern of:
Archive::Tar::Minitar::Input.open(io) do |i| inp.each do |entry| # ... end end
If a block is not provided, an enumerator will be created with the same behaviour.
# File lib/archive/tar/minitar/reader.rb, line 185 def self.each_entry(io) return to_enum(__method__, io) unless block_given? open(io) do |reader| reader.each_entry do |entry| yield entry end end end
Creates and returns a new Reader
object.
# File lib/archive/tar/minitar/reader.rb, line 196 def initialize(io) @io = io @init_pos = io.pos rescue nil end
With no associated block, Reader::open
is a synonym for Reader::new
. If the optional code block is given, it will be passed the new writer as an argument and the Reader
object will automatically be closed when the block terminates. In this instance, Reader::open
returns the value of the block.
# File lib/archive/tar/minitar/reader.rb, line 157 def self.open(io) reader = new(io) return reader unless block_given? # This exception context must remain, otherwise the stream closes on open # even if a block is not given. begin yield reader ensure reader.close end end
Public Instance Methods
# File lib/archive/tar/minitar/reader.rb, line 269 def close end
Returns false if the reader is open (it never closes).
# File lib/archive/tar/minitar/reader.rb, line 265 def closed? false end
Iterates through each entry in the data stream.
# File lib/archive/tar/minitar/reader.rb, line 219 def each_entry return to_enum unless block_given? loop do return if @io.eof? header = Archive::Tar::Minitar::PosixHeader.from_stream(@io) raise Archive::Tar::Minitar::InvalidTarStream unless header.valid? return if header.empty? raise Archive::Tar::Minitar::InvalidTarStream if header.size < 0 if header.long_name? name = @io.read(512).rstrip header = PosixHeader.from_stream(@io) return if header.empty? header.name = name end entry = EntryStream.new(header, @io) size = entry.size yield entry skip = (512 - (size % 512)) % 512 if Archive::Tar::Minitar.seekable?(@io, :seek) # avoid reading... @io.seek(size - entry.bytes_read, IO::SEEK_CUR) else pending = size - entry.bytes_read while pending > 0 bread = bytesize(@io.read([pending, 4096].min)) 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
Resets the read pointer to the beginning of data stream. Do not call this during a each
or each_entry
iteration. This only works with random access data streams that respond to rewind
and pos.
# File lib/archive/tar/minitar/reader.rb, line 204 def rewind if @init_pos.zero? unless Archive::Tar::Minitar.seekable?(@io, :rewind) raise Archive::Tar::Minitar::NonSeekableStream end @io.rewind else unless Archive::Tar::Minitar.seekable?(@io, :pos=) raise Archive::Tar::Minitar::NonSeekableStream end @io.pos = @init_pos end end