class Gem::Package::TarTestCase

# File lib/rubygems/package/tar_test_case.rb, line 9
def ASCIIZ(str, length)
  str + "\0" * (length - str.length)
end

# File lib/rubygems/package/tar_test_case.rb, line 13
def SP(s)
  s + " "
end

# File lib/rubygems/package/tar_test_case.rb, line 17
def SP_Z(s)
  s + " \0"
end

# File lib/rubygems/package/tar_test_case.rb, line 21
def Z(s)
  s + "\0"
end

# File lib/rubygems/package/tar_test_case.rb, line 25
def assert_headers_equal(expected, actual)
  expected = expected.to_s unless String === expected
  actual = actual.to_s unless String === actual

  fields = %w[
    name 100
    mode 8
    uid 8
    gid 8
    size 12
    mtime 12
    checksum 8
    typeflag 1
    linkname 100
    magic 6
    version 2
    uname 32
    gname 32
    devmajor 8
    devminor 8
    prefix 155
  ]

  offset = 0

  until fields.empty? do
    name = fields.shift
    length = fields.shift.to_i

    if name == "checksum" then
      chksum_off = offset
      offset += length
      next
    end

    assert_equal expected[offset, length], actual[offset, length],
                 "Field #{name} of the tar header differs."

    offset += length
  end

  assert_equal expected[chksum_off, 8], actual[chksum_off, 8]
end

# File lib/rubygems/package/tar_test_case.rb, line 69
def calc_checksum(header)
  sum = header.unpack("C*").inject{|s,a| s + a}
  SP(Z(to_oct(sum, 6)))
end

# File lib/rubygems/package/tar_test_case.rb, line 74
def header(type, fname, dname, length, mode, checksum = nil)
  checksum ||= " " * 8

  arr = [                  # struct tarfile_entry_posix
    ASCIIZ(fname, 100),    # char name[100];     ASCII + (Z unless filled)
    Z(to_oct(mode, 7)),    # char mode[8];       0 padded, octal null
    Z(to_oct(0, 7)),       # char uid[8];        ditto
    Z(to_oct(0, 7)),       # char gid[8];        ditto
    Z(to_oct(length, 11)), # char size[12];      0 padded, octal, null
    Z(to_oct(0, 11)),      # char mtime[12];     0 padded, octal, null
    checksum,              # char checksum[8];   0 padded, octal, null, space
    type,                  # char typeflag[1];   file: "0"  dir: "5"
    "\0" * 100,            # char linkname[100]; ASCII + (Z unless filled)
    "ustar\0",             # char magic[6];      "ustar\0"
    "00",                  # char version[2];    "00"
    ASCIIZ("wheel", 32),   # char uname[32];     ASCIIZ
    ASCIIZ("wheel", 32),   # char gname[32];     ASCIIZ
    Z(to_oct(0, 7)),       # char devmajor[8];   0 padded, octal, null
    Z(to_oct(0, 7)),       # char devminor[8];   0 padded, octal, null
    ASCIIZ(dname, 155)     # char prefix[155];   ASCII + (Z unless filled)
  ]

  format = "C100C8C8C8C12C12C8CC100C6C2C32C32C8C8C155"
  h = if RUBY_VERSION >= "1.9" then
        arr.join
      else
        arr = arr.join("").split(//).map{|x| x[0]}
        arr.pack format
      end
  ret = h + "\0" * (512 - h.size)
  assert_equal(512, ret.size)
  ret
end

# File lib/rubygems/package/tar_test_case.rb, line 108
def tar_dir_header(name, prefix, mode)
  h = header("5", name, prefix, 0, mode)
  checksum = calc_checksum(h)
  header("5", name, prefix, 0, mode, checksum)
end

# File lib/rubygems/package/tar_test_case.rb, line 114
def tar_file_header(fname, dname, mode, length)
  h = header("0", fname, dname, length, mode)
  checksum = calc_checksum(h)
  header("0", fname, dname, length, mode, checksum)
end

# File lib/rubygems/package/tar_test_case.rb, line 120
def to_oct(n, pad_size)
  "%0#{pad_size}o" % n
end

# File lib/rubygems/package/tar_test_case.rb, line 132
def util_dir_entry
  util_entry tar_dir_header("foo", "bar", 0)
end

# File lib/rubygems/package/tar_test_case.rb, line 124
def util_entry(tar)
  io = TempIO.new tar

  header = Gem::Package::TarHeader.from io

  Gem::Package::TarReader::Entry.new header, io
end