zip-rs-wasm/src/reader_spec.rs
2015-02-24 16:02:16 +01:00

107 lines
3.7 KiB
Rust

use std::io;
use std::io::prelude::*;
use std::num::FromPrimitive;
use result::{ZipResult, ZipError};
use types::ZipFile;
use compression::CompressionMethod;
use spec;
use util;
use util::ReadIntExt;
pub fn central_header_to_zip_file<R: Read+io::Seek>(reader: &mut R) -> ZipResult<ZipFile>
{
// Parse central header
let signature = try!(reader.read_le_u32());
if signature != spec::CENTRAL_DIRECTORY_HEADER_SIGNATURE
{
return Err(ZipError::InvalidZipFile("Invalid Central Directory header"))
}
try!(reader.read_le_u16());
try!(reader.read_le_u16());
let flags = try!(reader.read_le_u16());
let encrypted = flags & 1 == 1;
let is_utf8 = flags & (1 << 11) != 0;
let compression_method = try!(reader.read_le_u16());
let last_mod_time = try!(reader.read_le_u16());
let last_mod_date = try!(reader.read_le_u16());
let crc32 = try!(reader.read_le_u32());
let compressed_size = try!(reader.read_le_u32());
let uncompressed_size = try!(reader.read_le_u32());
let file_name_length = try!(reader.read_le_u16()) as usize;
let extra_field_length = try!(reader.read_le_u16()) as usize;
let file_comment_length = try!(reader.read_le_u16()) as usize;
try!(reader.read_le_u16());
try!(reader.read_le_u16());
try!(reader.read_le_u32());
let offset = try!(reader.read_le_u32()) as u64;
let file_name_raw = try!(reader.read_exact(file_name_length));
let extra_field = try!(reader.read_exact(extra_field_length));
let file_comment_raw = try!(reader.read_exact(file_comment_length));
let file_name = match is_utf8
{
true => String::from_utf8_lossy(&*file_name_raw).into_owned(),
false => ::cp437::to_string(&*file_name_raw),
};
let file_comment = match is_utf8
{
true => String::from_utf8_lossy(&*file_comment_raw).into_owned(),
false => ::cp437::to_string(&*file_comment_raw),
};
// Remember end of central header
let return_position = try!(reader.seek(io::SeekFrom::Current(0)));
// Parse local header
try!(reader.seek(io::SeekFrom::Start(offset)));
let signature = try!(reader.read_le_u32());
if signature != spec::LOCAL_FILE_HEADER_SIGNATURE
{
return Err(ZipError::InvalidZipFile("Invalid local file header"))
}
try!(reader.seek(io::SeekFrom::Current(22)));
let file_name_length = try!(reader.read_le_u16()) as u64;
let extra_field_length = try!(reader.read_le_u16()) as u64;
let magic_and_header = 4 + 22 + 2 + 2;
let data_start = offset as u64 + magic_and_header + file_name_length + extra_field_length;
// Construct the result
let mut result = ZipFile
{
encrypted: encrypted,
compression_method: FromPrimitive::from_u16(compression_method).unwrap_or(CompressionMethod::Unknown),
last_modified_time: util::msdos_datetime_to_tm(last_mod_time, last_mod_date),
crc32: crc32,
compressed_size: compressed_size as u64,
uncompressed_size: uncompressed_size as u64,
file_name: file_name,
file_comment: file_comment,
header_start: offset as u64,
data_start: data_start,
};
try!(parse_extra_field(&mut result, &*extra_field));
// Go back after the central header
try!(reader.seek(io::SeekFrom::Start(return_position)));
Ok(result)
}
fn parse_extra_field(_file: &mut ZipFile, data: &[u8]) -> ZipResult<()>
{
let mut reader = io::Cursor::new(data);
while (reader.position() as usize) < data.len()
{
let kind = try!(reader.read_le_u16());
let len = try!(reader.read_le_u16());
match kind
{
_ => try!(reader.seek(io::SeekFrom::Current(len as i64))),
};
}
Ok(())
}