diff options
| -rw-r--r-- | src/zip.cr | 172 |
1 files changed, 93 insertions, 79 deletions
@@ -4,6 +4,13 @@ require "zlib" module Zip VERSION = "0.1.0" + MAGIC = { + cdr_header: 0x02014b50_u32, + cdr_footer: 0x06054b50_u32, + file_header: 0x04034b50_u32, + file_footer: 0x08074b50_u32, + } + LE = IO::ByteFormat::LittleEndian # 4.4.4 general purpose bit flag: (2 bytes) @@ -142,14 +149,14 @@ module Zip class Error < Exception end - module Util - def self.write_time(io : IO, time : Time) : UInt64 + module TimeHelper + def write_time(io : IO, time : Time) : UInt32 # TODO 0_u32.to_u16.to_io(io, LE) 0_u32.to_u16.to_io(io, LE) # return number of bytes written - 4_u64 + 4_u32 end end @@ -162,12 +169,12 @@ module Zip end end - module NoneCompressor + module NoneCompressionHelper def compress_none(src_io, dst_io) crc = 0_u32 buf = Bytes.new(4096) - src_len = 0_u64 + src_len = 0_u32 while ((len = src_io.read(buf)) > 0) # TODO: crc32 @@ -181,11 +188,11 @@ module Zip end end - module DeflateCompressor + module DeflateCompressionHelper def compress_deflate(src_io, dst_io) crc = 0_u32 - src_len = 0_u64 - dst_len = 0_u64 + src_len = 0_u32 + dst_len = 0_u32 # create buffer and intermediate memory io buf = Bytes.new(4096) @@ -217,8 +224,9 @@ module Zip end class WriterEntry - include NoneCompressor - include DeflateCompressor + include TimeHelper + include NoneCompressionHelper + include DeflateCompressionHelper # TODO version needed to extract and header flags # (used for header and central header) @@ -226,7 +234,7 @@ module Zip GENERAL_FLAGS = GeneralFlags.flags(FOOTER, EFS) def initialize( - @pos : UInt64, + @pos : UInt32, @path : String, @io : IO, @method : CompressionMethod = CompressionMethod::DEFLATE, @@ -234,11 +242,11 @@ module Zip @comment : String = "", ) @crc = 0_u32 - @src_len = 0_u64 - @dst_len = 0_u64 + @src_len = 0_u32 + @dst_len = 0_u32 end - def to_s(dst_io) : UInt64 + def to_s(dst_io) : UInt32 # write header r = write_header(dst_io, @path, @method, @time) @@ -269,14 +277,12 @@ module Zip # extra field (variable size) # - HEADER_MAGIC = 0x04034b50_u32 - private def write_header( io : IO, path : String, method : CompressionMethod, time : Time, - ) : UInt64 + ) : UInt32 # get path length, in bytes path_len = path.bytesize @@ -285,23 +291,26 @@ module Zip raise "file path too long" if path_len >= UInt16::MAX raise "file path contains leading slash" if path[0] == '/' - # write magic, version needed, flags, and compression method - HEADER_MAGIC.to_io(io, LE) + # write magic (u32), version needed (u16), flags (u16), and + # compression method (u16) + MAGIC[:file_header].to_io(io, LE) VERSION_NEEDED.to_u16.to_io(io, LE) GENERAL_FLAGS.to_u16.to_io(io, LE) method.to_u16.to_io(io, LE) - # write time - Util.write_time(io, time) + # write time (u32) + write_time(io, time) - # crc, compressed size, uncompressed size + # crc (u32), compressed size (u32), uncompressed size (u32) # (these will be populated in the footer) 0_u32.to_io(io, LE) 0_u32.to_io(io, LE) 0_u32.to_io(io, LE) + + # write file path length (u16) path_len.to_u16.to_io(io, LE) - # write extras field length + # write extras field length (u16) extras_len = 0_u32 extras_len.to_u16.to_io(io, LE) @@ -312,7 +321,7 @@ module Zip # TODO: implement this # return number of bytes written - 30_u64 + path_len + extras_len + 30_u32 + path_len + extras_len end private def write_body(dst_io : IO) @@ -335,22 +344,22 @@ module Zip # 4.3.9.3 Although not originally assigned a signature, the value # 0x08074b50 has commonly been adopted as a signature value - FOOTER_MAGIC = 0x08074b50_u32 - private def write_footer( io : IO, crc : UInt32, - src_len : UInt64, - dst_len : UInt64, - ) : UInt64 - # write footer - FOOTER_MAGIC.to_io(io, LE) + src_len : UInt32, + dst_len : UInt32, + ) : UInt32 + # write magic (u32) + MAGIC[:file_footer].to_io(io, LE) + + # write crc (u32), compressed size (u32), and full size (u32) crc.to_io(io, LE) dst_len.to_io(io, LE) src_len.to_io(io, LE) # return number of bytes written - 16_u64 + 16_u32 end # @@ -376,23 +385,21 @@ module Zip # extra field (variable size) # file comment (variable size) - CENTRAL_MAGIC = 0x02014b50_u32 - # TODO: version made by, if unspecified CENTRAL_VERSION_MADE_BY = 0_u32 def write_central( io : IO, version : UInt32 = CENTRAL_VERSION_MADE_BY - ) : UInt64 - CENTRAL_MAGIC.to_io(io, LE) + ) : UInt32 + MAGIC[:cdr_header].to_io(io, LE) version.to_u16.to_io(io, LE) VERSION_NEEDED.to_u16.to_io(io, LE) GENERAL_FLAGS.to_u16.to_io(io, LE) @method.to_u16.to_io(io, LE) # write time - Util.write_time(io, @time) + write_time(io, @time) @crc.to_io(io, LE) @dst_len.to_io(io, LE) @@ -402,10 +409,11 @@ module Zip path_len = @path.bytesize path_len.to_u16.to_io(io, LE) - # write extras field length + # write extras field length (u16) extras_len = 0_u32 extras_len.to_u16.to_io(io, LE) + # write comment field length (u16) comment_len = @comment.bytesize comment_len.to_u16.to_io(io, LE) @@ -415,10 +423,10 @@ module Zip # write file attributes (internal, external) # TODO 0_u32.to_u16.to_io(io, LE) - 0_u32.to_u16.to_io(io, LE) + 0_u32.to_io(io, LE) # write local header offset - @pos.to_u32.to_io(io, LE) + @pos.to_io(io, LE) # write path field @path.to_s(io) @@ -430,10 +438,7 @@ module Zip @comment.to_s(io) # return number of bytes written - 30_u64 + path_len + extras_len - - # TODO - 0_u64 + 46_u32 + path_len + extras_len + comment_len end end @@ -441,7 +446,7 @@ module Zip class Writer def initialize( @io : IO, - @pos : UInt64 = 0, + @pos : UInt32 = 0, @comment : String = "", @version : UInt32 = 0, ) @@ -458,7 +463,7 @@ module Zip raise "already closed" if closed? end - def bytes_written : UInt64 + def bytes_written : UInt32 # return total number of bytes written @src_pos - @pos end @@ -474,7 +479,7 @@ module Zip end # write zip footer - write_footer(cdr_pos) + @pos += write_footer(cdr_pos, @pos - cdr_pos) # flag as closed @closed = true @@ -489,7 +494,7 @@ module Zip method : CompressionMethod = CompressionMethod::DEFLATE, time : Time = Time.now, comment : String = "", - ) : UInt64 + ) : UInt32 # cache input position src_pos = @pos @@ -522,7 +527,7 @@ module Zip method : CompressionMethod = CompressionMethod::DEFLATE, time : Time = Time.now, comment : String = "", - ) : UInt64 + ) : UInt32 add(path, MemoryIO.new(body), method, time, comment) end @@ -532,7 +537,7 @@ module Zip method : CompressionMethod = CompressionMethod::DEFLATE, time : Time = Time.now, comment : String = "", - ) : UInt64 + ) : UInt32 File.open(file_path, "rb") do |io| add(path, io, method, time, comment) end @@ -540,52 +545,61 @@ module Zip # 4.3.16 End of central directory record: # - # end of central dir signature 4 bytes (0x06054b50) - # number of this disk 2 bytes - # number of the disk with the - # start of the central directory 2 bytes - # total number of entries in the - # central directory on this disk 2 bytes - # total number of entries in - # the central directory 2 bytes - # size of the central directory 4 bytes - # offset of start of central - # directory with respect to - # the starting disk number 4 bytes - # .ZIP file comment length 2 bytes - # .ZIP file comment (variable size) - - FOOTER_MAGIC = 0x06054b50_u32 - - private def write_footer(cdr_pos : UInt64) - # write magic (u32), disk num (u16), start footer disk (u16) - FOOTER_MAGIC.to_io(@io, LE) + # * end of central dir signature 4 bytes (0x06054b50) + # * number of this disk 2 bytes + # * number of the disk with the + # start of the central directory 2 bytes + # * total number of entries in the + # central directory on this disk 2 bytes + # * total number of entries in + # the central directory 2 bytes + # * size of the central directory 4 bytes + # * offset of start of central + # directory with respect to + # the starting disk number 4 bytes + # * .ZIP file comment length 2 bytes + # * .ZIP file comment (variable size) + + private def write_footer( + cdr_pos : UInt32, + cdr_len : UInt32, + ) : UInt32 + # write magic (u32) + MAGIC[:cdr_footer].to_io(@io, LE) + + # write disk num (u16) and footer start disk (u16) 0_u32.to_u16.to_io(@io, LE) 0_u32.to_u16.to_io(@io, LE) - # write num entries (u16) / total entries (u16) + # write num entries (u16) and total entries (u16) num_entries = @entries.size num_entries.to_u16.to_io(@io, LE) num_entries.to_u16.to_io(@io, LE) - # write offset (u32) - (cdr_pos - @src_pos).to_u32.to_io(@io, LE) + # write cdr offset (u32) and cdr length (u32) + cdr_len.to_io(@io, LE) cdr_pos.to_io(@io, LE) + # get comment length (u16) + comment_len = @comment.bytesize + # write comment length (u16) and comment - @comment.bytesize.to_u16.to_io(@io, LE) + comment_len.to_u16.to_io(@io, LE) @comment.to_s(@io) + + # return number of bytes written + 22_u32 + comment_len end end def self.write( io : IO, - pos : UInt64 = 0_u64, + pos : UInt32 = 0_u32, comment : String = "", version : UInt32 = 0_u32, &cb : Writer -> \ - ) : UInt64 - r = 0_u64 + ) : UInt32 + r = 0_u32 begin w = Writer.new(io, pos, comment, version) cb.call(w) @@ -602,11 +616,11 @@ module Zip def self.write( path : String, - pos : UInt64 = 0_u64, + pos : UInt32 = 0_u32, comment : String = "", version : UInt32 = 0_u32, &cb : Writer -> \ - ) : UInt64 + ) : UInt32 File.open(path, "wb") do |io| write(io, pos, comment, version, &cb) end |