src/catar/encoder.rs: fix binary format, write goodby table

We still ned to sort the table (BST) ...
This commit is contained in:
Dietmar Maurer 2018-12-28 14:26:05 +01:00
parent 03fb895197
commit a0cc09b5f0
3 changed files with 82 additions and 25 deletions

View File

@ -37,7 +37,11 @@ fn backup_dir(
}
// fixme: implement chunked writer
let writer = std::fs::File::create("mytest.catar")?;
let writer = std::fs::OpenOptions::new()
.create(true)
.write(true)
.truncate(true)
.open("mytest.catar")?;
let path = std::path::PathBuf::from(path);

View File

@ -8,7 +8,7 @@ use std::os::unix::ffi::OsStrExt;
use std::os::unix::io::RawFd;
use std::path::{Path, PathBuf};
use std::ffi::{CStr, CString};
use std::ffi::CStr;
use nix::NixPath;
use nix::fcntl::OFlag;
@ -26,6 +26,7 @@ pub struct CaTarEncoder<W: Write> {
file_copy_buffer: Vec<u8>,
}
impl <W: Write> CaTarEncoder<W> {
pub fn encode(path: PathBuf, dir: &mut nix::dir::Dir, writer: W) -> Result<(), Error> {
@ -41,11 +42,8 @@ impl <W: Write> CaTarEncoder<W> {
file_copy_buffer,
};
// todo: use scandirat??
let name = CString::new(".")?;
me.encode_dir(dir, &name)?;
me.encode_dir(dir)?;
Ok(())
}
@ -57,7 +55,7 @@ impl <W: Write> CaTarEncoder<W> {
}
fn flush_copy_buffer(&mut self, size: usize) -> Result<(), Error> {
self.writer.write(&self.file_copy_buffer)?;
self.writer.write(&self.file_copy_buffer[..size])?;
self.writer_pos += size;
Ok(())
}
@ -67,7 +65,7 @@ impl <W: Write> CaTarEncoder<W> {
let mut buffer = [0u8; std::mem::size_of::<CaFormatHeader>()];
let mut header = crate::tools::map_struct_mut::<CaFormatHeader>(&mut buffer)?;
header.size = u64::to_le((std::mem::size_of::<CaFormatHeader>() as u64) + size);
header.htype = htype;
header.htype = u64::to_le(htype);
self.write(&buffer)?;
@ -88,11 +86,11 @@ impl <W: Write> CaTarEncoder<W> {
let mut buffer = [0u8; std::mem::size_of::<CaFormatHeader>() + std::mem::size_of::<CaFormatEntry>()];
let mut header = crate::tools::map_struct_mut::<CaFormatHeader>(&mut buffer)?;
header.size = u64::to_le((std::mem::size_of::<CaFormatHeader>() + std::mem::size_of::<CaFormatEntry>()) as u64);
header.htype = CA_FORMAT_ENTRY;
header.htype = u64::to_le(CA_FORMAT_ENTRY);
let mut entry = crate::tools::map_struct_mut::<CaFormatEntry>(&mut buffer[std::mem::size_of::<CaFormatHeader>()..])?;
entry.feature_flags = 0; // fixme ??
entry.feature_flags = u64::to_le(CA_FORMAT_FEATURE_FLAGS_MAX);
if (stat.st_mode & libc::S_IFMT) == libc::S_IFLNK {
entry.mode = u64::to_le((libc::S_IFLNK | 0o777) as u64);
@ -114,7 +112,7 @@ impl <W: Write> CaTarEncoder<W> {
Ok(())
}
fn encode_dir(&mut self, dir: &mut nix::dir::Dir, name: &CStr) -> Result<(), Error> {
fn encode_dir(&mut self, dir: &mut nix::dir::Dir) -> Result<(), Error> {
println!("encode_dir: {:?} start {}", self.current_path, self.writer_pos);
@ -131,9 +129,9 @@ impl <W: Write> CaTarEncoder<W> {
bail!("got unexpected file type {:?} (not a directory)", self.current_path);
}
self.write_entry(&dir_stat)?;
let dir_start_pos = self.writer_pos;
self.write_filename(name)?;
self.write_entry(&dir_stat)?;
for entry in dir.iter() {
let entry = match entry {
@ -158,12 +156,19 @@ impl <W: Write> CaTarEncoder<W> {
name_list.sort_unstable_by(|a, b| a.0.cmp(&b.0));
let mut goodby_items = vec![];
for (filename, stat) in &name_list {
self.current_path.push(std::ffi::OsStr::from_bytes(filename.as_bytes()));
let start_pos = self.writer_pos;
self.write_filename(&filename)?;
if (stat.st_mode & libc::S_IFMT) == libc::S_IFDIR {
match nix::dir::Dir::openat(rawfd, filename.as_ref(), OFlag::O_NOFOLLOW, Mode::empty()) {
Ok(mut dir) => self.encode_dir(&mut dir, &filename)?,
Ok(mut dir) => self.encode_dir(&mut dir)?,
Err(nix::Error::Sys(Errno::ENOENT)) => self.report_vanished_file(&self.current_path)?,
Err(err) => bail!("open dir {:?} failed - {}", self.current_path, err),
}
@ -171,7 +176,7 @@ impl <W: Write> CaTarEncoder<W> {
} else if (stat.st_mode & libc::S_IFMT) == libc::S_IFREG {
match nix::fcntl::openat(rawfd, filename.as_ref(), OFlag::O_NOFOLLOW, Mode::empty()) {
Ok(filefd) => {
let res = self.encode_file(filefd, &filename);
let res = self.encode_file(filefd);
let _ = nix::unistd::close(filefd); // ignore close errors
res?;
}
@ -186,7 +191,7 @@ impl <W: Write> CaTarEncoder<W> {
})?;
match Errno::result(res) {
Ok(len) => self.encode_symlink(&buffer[..(len as usize)], &stat, &filename)?,
Ok(len) => self.encode_symlink(&buffer[..(len as usize)], &stat)?,
Err(nix::Error::Sys(Errno::ENOENT)) => self.report_vanished_file(&self.current_path)?,
Err(err) => bail!("readlink {:?} failed - {}", self.current_path, err),
}
@ -194,17 +199,60 @@ impl <W: Write> CaTarEncoder<W> {
bail!("unsupported file type (mode {:o} {:?})", stat.st_mode, self.current_path);
}
let end_pos = self.writer_pos;
goodby_items.push(CaFormatGoodbyeItem {
offset: start_pos as u64,
size: (end_pos - start_pos) as u64,
hash: compute_goodby_hash(&filename),
});
self.current_path.pop();
}
let entry_count = name_list.len();
println!("encode_dir: {:?} end {}", self.current_path, self.writer_pos);
let goodby_start = self.writer_pos as u64;
let goodby_table_size = (goodby_items.len() + 1)*std::mem::size_of::<CaFormatGoodbyeItem>();
for item in &mut goodby_items {
item.offset = goodby_start - item.offset;
}
// fixme: sort goodby_items (BST)
let goodby_offset = self.writer_pos - dir_start_pos;
// append CaFormatGoodbyeTail as last item
goodby_items.push(CaFormatGoodbyeItem {
offset: goodby_offset as u64,
size: (goodby_table_size + std::mem::size_of::<CaFormatHeader>()) as u64,
hash: CA_FORMAT_GOODBYE_TAIL_MARKER,
});
self.write_header(CA_FORMAT_GOODBYE, goodby_table_size as u64)?;
if goodby_table_size > FILE_COPY_BUFFER_SIZE {
bail!("goodby table too large ({} > {})", goodby_table_size, FILE_COPY_BUFFER_SIZE);
}
let buffer = &mut self.file_copy_buffer;
let buffer_ptr = buffer.as_ptr();
for (i, item) in goodby_items.iter().enumerate() {
unsafe {
*(buffer_ptr.add(i*std::mem::size_of::<CaFormatGoodbyeItem>()) as *mut u64) = u64::to_le(item.offset);
*(buffer_ptr.add(i*std::mem::size_of::<CaFormatGoodbyeItem>()+8) as *mut u64) = u64::to_le(item.size);
*(buffer_ptr.add(i*std::mem::size_of::<CaFormatGoodbyeItem>()+16) as *mut u64) = u64::to_le(item.hash);
}
}
self.flush_copy_buffer(goodby_table_size)?;
println!("encode_dir: {:?} end1 {}", self.current_path, self.writer_pos);
Ok(())
}
fn encode_file(&mut self, filefd: RawFd, name: &CStr) -> Result<(), Error> {
fn encode_file(&mut self, filefd: RawFd) -> Result<(), Error> {
println!("encode_file: {:?}", self.current_path);
@ -219,8 +267,6 @@ impl <W: Write> CaTarEncoder<W> {
self.write_entry(&stat)?;
self.write_filename(name)?;
let size = stat.st_size as u64;
self.write_header(CA_FORMAT_PAYLOAD, size)?;
@ -256,14 +302,12 @@ impl <W: Write> CaTarEncoder<W> {
Ok(())
}
fn encode_symlink(&mut self, target: &[u8], stat: &FileStat, name: &CStr) -> Result<(), Error> {
fn encode_symlink(&mut self, target: &[u8], stat: &FileStat) -> Result<(), Error> {
println!("encode_symlink: {:?} -> {:?}", self.current_path, target);
self.write_entry(stat)?;
self.write_filename(name)?;
self.write_header(CA_FORMAT_SYMLINK, target.len() as u64)?;
self.write(target)?;
@ -278,5 +322,12 @@ impl <W: Write> CaTarEncoder<W> {
Ok(())
}
}
fn compute_goodby_hash(name: &CStr) -> u64 {
use std::hash::Hasher;
let mut hasher = std::hash::SipHasher::new_with_keys(0x8574442b0f1d84b3, 0x2736ed30d1c22ec1);
hasher.write(name.to_bytes());
hasher.finish()
}

View File

@ -9,6 +9,8 @@ pub const CA_FORMAT_GOODBYE: u64 = 0xdfd35c5e8327c403;
/* The end marker used in the GOODBYE object */
pub const CA_FORMAT_GOODBYE_TAIL_MARKER: u64 = 0x57446fa533702943;
pub const CA_FORMAT_FEATURE_FLAGS_MAX: u64 = 0xb000_0001_ffef_fe26; // fixme: ?
#[repr(C)]
pub struct CaFormatHeader {
pub size: u64,