lib/zip/central_directory.rb
module Zip
class CentralDirectory
include Enumerable
END_OF_CDS = 0x06054b50
ZIP64_END_OF_CDS = 0x06064b50
ZIP64_EOCD_LOCATOR = 0x07064b50
MAX_END_OF_CDS_SIZE = 65536 + 18
STATIC_EOCD_SIZE = 22
attr_reader :comment
# Returns an Enumerable containing the entries.
def entries
@entry_set.entries
end
def initialize(entries = EntrySet.new, comment = '') #:nodoc:
super()
@entry_set = entries.kind_of?(EntrySet) ? entries : EntrySet.new(entries)
@comment = comment
end
def write_to_stream(io) #:nodoc:
cdir_offset = io.tell
@entry_set.each { |entry| entry.write_c_dir_entry(io) }
eocd_offset = io.tell
cdir_size = eocd_offset - cdir_offset
if ::Zip.write_zip64_support
need_zip64_eocd = cdir_offset > 0xFFFFFFFF || cdir_size > 0xFFFFFFFF || @entry_set.size > 0xFFFF
need_zip64_eocd ||= @entry_set.any? { |entry| entry.extra['Zip64'] }
if need_zip64_eocd
write_64_e_o_c_d(io, cdir_offset, cdir_size)
write_64_eocd_locator(io, eocd_offset)
end
end
write_e_o_c_d(io, cdir_offset, cdir_size)
end
def write_e_o_c_d(io, offset, cdir_size) #:nodoc:
tmp = [
END_OF_CDS,
0, # @numberOfThisDisk
0, # @numberOfDiskWithStartOfCDir
@entry_set ? [@entry_set.size, 0xFFFF].min : 0,
@entry_set ? [@entry_set.size, 0xFFFF].min : 0,
[cdir_size, 0xFFFFFFFF].min,
[offset, 0xFFFFFFFF].min,
@comment ? @comment.bytesize : 0
]
io << tmp.pack('VvvvvVVv')
io << @comment
end
private :write_e_o_c_d
def write_64_e_o_c_d(io, offset, cdir_size) #:nodoc:
tmp = [
ZIP64_END_OF_CDS,
44, # size of zip64 end of central directory record (excludes signature and field itself)
VERSION_MADE_BY,
VERSION_NEEDED_TO_EXTRACT_ZIP64,
0, # @numberOfThisDisk
0, # @numberOfDiskWithStartOfCDir
@entry_set ? @entry_set.size : 0, # number of entries on this disk
@entry_set ? @entry_set.size : 0, # number of entries total
cdir_size, # size of central directory
offset, # offset of start of central directory in its disk
]
io << tmp.pack('VQ<vvVVQ<Q<Q<Q<')
end
private :write_64_e_o_c_d
def write_64_eocd_locator(io, zip64_eocd_offset)
tmp = [
ZIP64_EOCD_LOCATOR,
0, # number of disk containing the start of zip64 eocd record
zip64_eocd_offset, # offset of the start of zip64 eocd record in its disk
1 # total number of disks
]
io << tmp.pack('VVQ<V')
end
private :write_64_eocd_locator
def read_64_e_o_c_d(buf) #:nodoc:
buf = get_64_e_o_c_d(buf)
@size_of_zip64_e_o_c_d = Entry.read_zip_64_long(buf)
@version_made_by = Entry.read_zip_short(buf)
@version_needed_for_extract = Entry.read_zip_short(buf)
@number_of_this_disk = Entry.read_zip_long(buf)
@number_of_disk_with_start_of_cdir = Entry.read_zip_long(buf)
@total_number_of_entries_in_cdir_on_this_disk = Entry.read_zip_64_long(buf)
@size = Entry.read_zip_64_long(buf)
@size_in_bytes = Entry.read_zip_64_long(buf)
@cdir_offset = Entry.read_zip_64_long(buf)
@zip_64_extensible = buf.slice!(0, buf.bytesize)
raise Error, "Zip consistency problem while reading eocd structure" unless buf.size == 0
end
def read_e_o_c_d(buf) #:nodoc:
buf = get_e_o_c_d(buf)
@number_of_this_disk = Entry.read_zip_short(buf)
@number_of_disk_with_start_of_cdir = Entry.read_zip_short(buf)
@total_number_of_entries_in_cdir_on_this_disk = Entry.read_zip_short(buf)
@size = Entry.read_zip_short(buf)
@size_in_bytes = Entry.read_zip_long(buf)
@cdir_offset = Entry.read_zip_long(buf)
comment_length = Entry.read_zip_short(buf)
@comment = if comment_length.to_i <= 0
buf.slice!(0, buf.size)
else
buf.read(comment_length)
end
raise Error, "Zip consistency problem while reading eocd structure" unless buf.size == 0
end
def read_central_directory_entries(io) #:nodoc:
begin
io.seek(@cdir_offset, IO::SEEK_SET)
rescue Errno::EINVAL
raise Error, "Zip consistency problem while reading central directory entry"
end
@entry_set = EntrySet.new
@size.times do
@entry_set << Entry.read_c_dir_entry(io)
end
end
def read_from_stream(io) #:nodoc:
buf = start_buf(io)
if self.zip64_file?(buf)
read_64_e_o_c_d(buf)
else
read_e_o_c_d(buf)
end
read_central_directory_entries(io)
end
def get_e_o_c_d(buf) #:nodoc:
sig_index = buf.rindex([END_OF_CDS].pack('V'))
raise Error, "Zip end of central directory signature not found" unless sig_index
buf = buf.slice!((sig_index + 4)..(buf.bytesize))
def buf.read(count)
slice!(0, count)
end
buf
end
def zip64_file?(buf)
buf.rindex([ZIP64_END_OF_CDS].pack('V')) && buf.rindex([ZIP64_EOCD_LOCATOR].pack('V'))
end
def start_buf(io)
begin
io.seek(-MAX_END_OF_CDS_SIZE, IO::SEEK_END)
rescue Errno::EINVAL
io.seek(0, IO::SEEK_SET)
end
io.read
end
def get_64_e_o_c_d(buf) #:nodoc:
zip_64_start = buf.rindex([ZIP64_END_OF_CDS].pack('V'))
raise Error, "Zip64 end of central directory signature not found" unless zip_64_start
zip_64_locator = buf.rindex([ZIP64_EOCD_LOCATOR].pack('V'))
raise Error, "Zip64 end of central directory signature locator not found" unless zip_64_locator
buf = buf.slice!((zip_64_start + 4)..zip_64_locator)
def buf.read(count)
slice!(0, count)
end
buf
end
# For iterating over the entries.
def each(&proc)
@entry_set.each(&proc)
end
# Returns the number of entries in the central directory (and
# consequently in the zip archive).
def size
@entry_set.size
end
def self.read_from_stream(io) #:nodoc:
cdir = new
cdir.read_from_stream(io)
return cdir
rescue Error
return nil
end
def ==(other) #:nodoc:
return false unless other.kind_of?(CentralDirectory)
@entry_set.entries.sort == other.entries.sort && comment == other.comment
end
end
end
# Copyright (C) 2002, 2003 Thomas Sondergaard
# rubyzip is free software; you can redistribute it and/or
# modify it under the terms of the ruby license.