use std::io;
use std::io::prelude::*;
use result::{ZipResult, ZipError};
use podio::{ReadPodExt, WritePodExt, LittleEndian};
pub const LOCAL_FILE_HEADER_SIGNATURE : u32 = 0x04034b50;
pub const CENTRAL_DIRECTORY_HEADER_SIGNATURE : u32 = 0x02014b50;
const CENTRAL_DIRECTORY_END_SIGNATURE : u32 = 0x06054b50;
pub const ZIP64_CENTRAL_DIRECTORY_END_SIGNATURE : u32 = 0x06064b50;
const ZIP64_CENTRAL_DIRECTORY_END_LOCATOR_SIGNATURE : u32 = 0x07064b50;
pub struct CentralDirectoryEnd
{
pub disk_number: u16,
pub disk_with_central_directory: u16,
pub number_of_files_on_this_disk: u16,
pub number_of_files: u16,
pub central_directory_size: u32,
pub central_directory_offset: u32,
pub zip_file_comment: Vec<u8>,
}
impl CentralDirectoryEnd
{
pub fn parse<T: Read>(reader: &mut T) -> ZipResult<CentralDirectoryEnd>
{
let magic = try!(reader.read_u32::<LittleEndian>());
if magic != CENTRAL_DIRECTORY_END_SIGNATURE
{
return Err(ZipError::InvalidArchive("Invalid digital signature header"))
}
let disk_number = try!(reader.read_u16::<LittleEndian>());
let disk_with_central_directory = try!(reader.read_u16::<LittleEndian>());
let number_of_files_on_this_disk = try!(reader.read_u16::<LittleEndian>());
let number_of_files = try!(reader.read_u16::<LittleEndian>());
let central_directory_size = try!(reader.read_u32::<LittleEndian>());
let central_directory_offset = try!(reader.read_u32::<LittleEndian>());
let zip_file_comment_length = try!(reader.read_u16::<LittleEndian>()) as usize;
let zip_file_comment = try!(ReadPodExt::read_exact(reader, zip_file_comment_length));
Ok(CentralDirectoryEnd
{
disk_number: disk_number,
disk_with_central_directory: disk_with_central_directory,
number_of_files_on_this_disk: number_of_files_on_this_disk,
number_of_files: number_of_files,
central_directory_size: central_directory_size,
central_directory_offset: central_directory_offset,
zip_file_comment: zip_file_comment,
})
}
pub fn find_and_parse<T: Read+io::Seek>(reader: &mut T) -> ZipResult<(CentralDirectoryEnd, u64)>
{
const HEADER_SIZE: u64 = 22;
const BYTES_BETWEEN_MAGIC_AND_COMMENT_SIZE: u64 = HEADER_SIZE - 6;
let file_length = try!(reader.seek(io::SeekFrom::End(0)));
let search_upper_bound = file_length.checked_sub(HEADER_SIZE + ::std::u16::MAX as u64).unwrap_or(0);
if file_length < HEADER_SIZE {
return Err(ZipError::InvalidArchive("Invalid zip header"));
}
let mut pos = file_length - HEADER_SIZE;
while pos >= search_upper_bound
{
try!(reader.seek(io::SeekFrom::Start(pos as u64)));
if try!(reader.read_u32::<LittleEndian>()) == CENTRAL_DIRECTORY_END_SIGNATURE
{
try!(reader.seek(io::SeekFrom::Current(BYTES_BETWEEN_MAGIC_AND_COMMENT_SIZE as i64)));
let comment_length = try!(reader.read_u16::<LittleEndian>()) as u64;
if file_length - pos - HEADER_SIZE == comment_length
{
let cde_start_pos = try!(reader.seek(io::SeekFrom::Start(pos as u64)));
return CentralDirectoryEnd::parse(reader).map(|cde| (cde, cde_start_pos));
}
}
pos = match pos.checked_sub(1) {
Some(p) => p,
None => break,
};
}
Err(ZipError::InvalidArchive("Could not find central directory end"))
}
pub fn write<T: Write>(&self, writer: &mut T) -> ZipResult<()>
{
try!(writer.write_u32::<LittleEndian>(CENTRAL_DIRECTORY_END_SIGNATURE));
try!(writer.write_u16::<LittleEndian>(self.disk_number));
try!(writer.write_u16::<LittleEndian>(self.disk_with_central_directory));
try!(writer.write_u16::<LittleEndian>(self.number_of_files_on_this_disk));
try!(writer.write_u16::<LittleEndian>(self.number_of_files));
try!(writer.write_u32::<LittleEndian>(self.central_directory_size));
try!(writer.write_u32::<LittleEndian>(self.central_directory_offset));
try!(writer.write_u16::<LittleEndian>(self.zip_file_comment.len() as u16));
try!(writer.write_all(&self.zip_file_comment));
Ok(())
}
}
pub struct Zip64CentralDirectoryEndLocator
{
pub disk_with_central_directory: u32,
pub end_of_central_directory_offset: u64,
pub number_of_disks: u32,
}
impl Zip64CentralDirectoryEndLocator
{
pub fn parse<T: Read>(reader: &mut T) -> ZipResult<Zip64CentralDirectoryEndLocator>
{
let magic = try!(reader.read_u32::<LittleEndian>());
if magic != ZIP64_CENTRAL_DIRECTORY_END_LOCATOR_SIGNATURE
{
return Err(ZipError::InvalidArchive("Invalid zip64 locator digital signature header"))
}
let disk_with_central_directory = try!(reader.read_u32::<LittleEndian>());
let end_of_central_directory_offset = try!(reader.read_u64::<LittleEndian>());
let number_of_disks = try!(reader.read_u32::<LittleEndian>());
Ok(Zip64CentralDirectoryEndLocator
{
disk_with_central_directory: disk_with_central_directory,
end_of_central_directory_offset: end_of_central_directory_offset,
number_of_disks: number_of_disks,
})
}
}
pub struct Zip64CentralDirectoryEnd
{
pub version_made_by: u16,
pub version_needed_to_extract: u16,
pub disk_number: u32,
pub disk_with_central_directory: u32,
pub number_of_files_on_this_disk: u64,
pub number_of_files: u64,
pub central_directory_size: u64,
pub central_directory_offset: u64,
}
impl Zip64CentralDirectoryEnd
{
pub fn find_and_parse<T: Read+io::Seek>(reader: &mut T,
nominal_offset: u64,
search_upper_bound: u64) -> ZipResult<(Zip64CentralDirectoryEnd, u64)>
{
let mut pos = nominal_offset;
while pos <= search_upper_bound
{
reader.seek(io::SeekFrom::Start(pos))?;
if reader.read_u32::<LittleEndian>()? == ZIP64_CENTRAL_DIRECTORY_END_SIGNATURE
{
let archive_offset = pos - nominal_offset;
let _record_size = try!(reader.read_u64::<LittleEndian>());
let version_made_by = try!(reader.read_u16::<LittleEndian>());
let version_needed_to_extract = try!(reader.read_u16::<LittleEndian>());
let disk_number = try!(reader.read_u32::<LittleEndian>());
let disk_with_central_directory = try!(reader.read_u32::<LittleEndian>());
let number_of_files_on_this_disk = try!(reader.read_u64::<LittleEndian>());
let number_of_files = try!(reader.read_u64::<LittleEndian>());
let central_directory_size = try!(reader.read_u64::<LittleEndian>());
let central_directory_offset = try!(reader.read_u64::<LittleEndian>());
return Ok((Zip64CentralDirectoryEnd
{
version_made_by: version_made_by,
version_needed_to_extract: version_needed_to_extract,
disk_number: disk_number,
disk_with_central_directory: disk_with_central_directory,
number_of_files_on_this_disk: number_of_files_on_this_disk,
number_of_files: number_of_files,
central_directory_size: central_directory_size,
central_directory_offset: central_directory_offset,
}, archive_offset));
}
pos += 1;
}
Err(ZipError::InvalidArchive("Could not find ZIP64 central directory end"))
}
}