231 lines
7.4 KiB
Lua

module("luarocks.tools.zip", package.seeall)
local zlib = require "zlib"
local function number_to_bytestring(number, nbytes)
local out = {}
for i = 1, nbytes do
local byte = number % 256
table.insert(out, string.char(byte))
number = (number - byte) / 256
end
return table.concat(out)
end
--- Return a zip handle open for writing.
-- @param name filename of the zipfile to be created.
-- @return a zip handle, or nil in case of error.
function write_open(name)
local zf = {}
zf.ziphandle = io.open(name, "w")
if not zf.ziphandle then
return nil
end
zf.files = {}
zf.in_open_file = false
return zf
end
--- Begin a new file to be stored inside the zipfile.
-- @param zf handle of the zipfile being written.
-- @param filename filenome of the file to be added to the zipfile.
-- @return true if succeeded, nil in case of failure.
function write_open_new_file_in_zip(zf, filename)
if zf.in_open_file then
close_file_in_zip(zf)
return nil
end
local lfh = {}
zf.local_file_header = lfh
lfh.last_mod_file_time = 0 -- TODO
lfh.last_mod_file_date = 0 -- TODO
lfh.crc32 = 0 -- initial value
lfh.compressed_size = 0 -- unknown yet
lfh.uncompressed_size = 0 -- unknown yet
lfh.file_name_length = #filename
lfh.extra_field_length = 0
lfh.file_name = filename:gsub("\\", "/")
zf.in_open_file = true
zf.data = {}
return true
end
--- Write data to the file currently being stored in the zipfile.
-- @param zf handle of the zipfile being written.
-- @param buf string containing data to be written.
-- @return true if succeeded, nil in case of failure.
function write_in_file_in_zip(zf, buf)
if not zf.in_open_file then
return nil
end
local lfh = zf.local_file_header
local cbuf = zlib.compress(buf):sub(3, -5)
lfh.crc32 = zlib.crc32(lfh.crc32, buf)
lfh.compressed_size = lfh.compressed_size + #cbuf
lfh.uncompressed_size = lfh.uncompressed_size + #buf
table.insert(zf.data, cbuf)
return true
end
--- Complete the writing of a file stored in the zipfile.
-- @param zf handle of the zipfile being written.
-- @return true if succeeded, nil in case of failure.
function write_close_file_in_zip(zf)
local zh = zf.ziphandle
if not zf.in_open_file then
return nil
end
-- Local file header
local lfh = zf.local_file_header
lfh.offset = zh:seek()
zh:write(number_to_bytestring(0x04034b50, 4)) -- signature
zh:write(number_to_bytestring(20, 2)) -- version needed to extract: 2.0
zh:write(number_to_bytestring(0, 2)) -- general purpose bit flag
zh:write(number_to_bytestring(8, 2)) -- compression method: deflate
zh:write(number_to_bytestring(lfh.last_mod_file_time, 2))
zh:write(number_to_bytestring(lfh.last_mod_file_date, 2))
zh:write(number_to_bytestring(lfh.crc32, 4))
zh:write(number_to_bytestring(lfh.compressed_size, 4))
zh:write(number_to_bytestring(lfh.uncompressed_size, 4))
zh:write(number_to_bytestring(lfh.file_name_length, 2))
zh:write(number_to_bytestring(lfh.extra_field_length, 2))
zh:write(lfh.file_name)
-- File data
for _, cbuf in ipairs(zf.data) do
zh:write(cbuf)
end
-- Data descriptor
zh:write(number_to_bytestring(lfh.crc32, 4))
zh:write(number_to_bytestring(lfh.compressed_size, 4))
zh:write(number_to_bytestring(lfh.uncompressed_size, 4))
table.insert(zf.files, lfh)
zf.in_open_file = false
return true
end
--- Complete the writing of the zipfile.
-- @param zf handle of the zipfile being written.
-- @return true if succeeded, nil in case of failure.
function write_close(zf)
local zh = zf.ziphandle
local central_directory_offset = zh:seek()
local size_of_central_directory = 0
-- Central directory structure
for _, lfh in ipairs(zf.files) do
zh:write(number_to_bytestring(0x02014b50, 4)) -- signature
zh:write(number_to_bytestring(3, 2)) -- version made by: UNIX
zh:write(number_to_bytestring(20, 2)) -- version needed to extract: 2.0
zh:write(number_to_bytestring(0, 2)) -- general purpose bit flag
zh:write(number_to_bytestring(8, 2)) -- compression method: deflate
zh:write(number_to_bytestring(lfh.last_mod_file_time, 2))
zh:write(number_to_bytestring(lfh.last_mod_file_date, 2))
zh:write(number_to_bytestring(lfh.crc32, 4))
zh:write(number_to_bytestring(lfh.compressed_size, 4))
zh:write(number_to_bytestring(lfh.uncompressed_size, 4))
zh:write(number_to_bytestring(lfh.file_name_length, 2))
zh:write(number_to_bytestring(lfh.extra_field_length, 2))
zh:write(number_to_bytestring(0, 2)) -- file comment length
zh:write(number_to_bytestring(0, 2)) -- disk number start
zh:write(number_to_bytestring(0, 2)) -- internal file attributes
zh:write(number_to_bytestring(0, 4)) -- external file attributes
zh:write(number_to_bytestring(lfh.offset, 4)) -- relative offset of local header
zh:write(lfh.file_name)
size_of_central_directory = size_of_central_directory + 46 + lfh.file_name_length
end
-- End of central directory record
zh:write(number_to_bytestring(0x06054b50, 4)) -- signature
zh:write(number_to_bytestring(0, 2)) -- number of this disk
zh:write(number_to_bytestring(0, 2)) -- number of disk with start of central directory
zh:write(number_to_bytestring(#zf.files, 2)) -- total number of entries in the central dir on this disk
zh:write(number_to_bytestring(#zf.files, 2)) -- total number of entries in the central dir
zh:write(number_to_bytestring(size_of_central_directory, 4))
zh:write(number_to_bytestring(central_directory_offset, 4))
zh:write(number_to_bytestring(0, 2)) -- zip file comment length
zh:close()
return true
end
-- @return boolean or (boolean, string): true on success,
-- false and an error message on failure.
local function add_to_zip(zf, file)
local fin
local ok, err = write_open_new_file_in_zip(zf, file)
if not ok then
err = "error in opening "..file.." in zipfile"
else
fin = io.open(file, "rb")
if not fin then
ok = false
err = "error opening "..file.." for reading"
end
end
while ok do
local buf = fin:read(size_buf)
if not buf then
break
end
ok = write_in_file_in_zip(zf, buf)
if not ok then
err = "error in writing "..file.." in the zipfile"
end
end
if fin then
fin:close()
end
if ok then
ok = write_close_file_in_zip(zf)
if not ok then
err = "error in writing "..file.." in the zipfile"
end
end
return ok == true, err
end
--- Compress files in a .zip archive.
-- @param zipfile string: pathname of .zip archive to be created.
-- @param ... Filenames to be stored in the archive are given as
-- additional arguments.
-- @return boolean or (boolean, string): true on success,
-- false and an error message on failure.
function zip(zipfile, ...)
local zf = write_open(filename)
if not zf then
return nil, "error opening "..filename
end
local ok, err
for _, file in pairs({...}) do
if fs.is_dir(file) then
for _, file in pairs(fs.find(file)) do
if fs.is_file(file) then
ok, err = add_to_zip(file)
if not ok then break end
end
end
else
ok, err = add_to_zip(file)
if not ok then break end
end
end
local ok = write_close(zf)
if not ok then
return false, "error closing "..filename
end
return ok, err
end