src/pxar/catalog.rs: new catalog helper

This commit is contained in:
Dietmar Maurer 2019-08-09 08:11:32 +02:00
parent 977eeb24f6
commit aea0815d32
2 changed files with 265 additions and 0 deletions

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@ -71,4 +71,6 @@ pub use match_pattern::*;
mod dir_stack;
pub use dir_stack::*;
pub mod catalog;
mod helper;

263
src/pxar/catalog.rs Normal file
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@ -0,0 +1,263 @@
//! File list Catalog
//!
//! A file list catalog simply store a directory tree. Such catalogs
//! may be used as index to do a fast search for files.
use failure::*;
use std::io::{Read, BufRead, Write, BufReader};
use std::fs::File;
use std::convert::TryFrom;
use std::ffi::{CStr, CString};
use chrono::offset::{TimeZone, Local};
use proxmox::tools::io::ReadExt;
#[repr(u8)]
#[derive(Copy,Clone,PartialEq)]
pub enum CatalogEntryType {
Directory = b'd',
File = b'f',
Symlink = b'l',
Hardlink = b'h',
BlockDevice = b'b',
CharDevice = b'c',
Fifo = b'p', // Fifo,Pipe
Socket = b's',
}
impl TryFrom<u8> for CatalogEntryType {
type Error=Error;
fn try_from(value: u8) -> Result<Self, Error> {
Ok(match value {
b'd' => CatalogEntryType::Directory,
b'f' => CatalogEntryType::File,
b'l' => CatalogEntryType::Symlink,
b'h' => CatalogEntryType::Hardlink,
b'b' => CatalogEntryType::BlockDevice,
b'c' => CatalogEntryType::CharDevice,
b'p' => CatalogEntryType::Fifo,
b's' => CatalogEntryType::Socket,
_ => bail!("invalid CatalogEntryType value '{}'", char::from(value)),
})
}
}
pub trait BackupCatalogWriter {
fn start_directory(&mut self, name: &CStr) -> Result<(), Error>;
fn end_directory(&mut self) -> Result<(), Error>;
fn add_file(&mut self, name: &CStr, size: u64, mtime: u64) -> Result<(), Error>;
fn add_symlink(&mut self, name: &CStr) -> Result<(), Error>;
fn add_hardlink(&mut self, name: &CStr) -> Result<(), Error>;
fn add_block_device(&mut self, name: &CStr) -> Result<(), Error>;
fn add_char_device(&mut self, name: &CStr) -> Result<(), Error>;
fn add_fifo(&mut self, name: &CStr) -> Result<(), Error>;
fn add_socket(&mut self, name: &CStr) -> Result<(), Error>;
}
pub struct SimpleCatalog {
writer: std::fs::File,
level: usize,
}
impl SimpleCatalog {
pub fn new<P: AsRef<std::path::Path>>(path: P) -> Result<Self, Error> {
let writer = std::fs::OpenOptions::new()
.create(true)
.truncate(true)
.write(true)
.open(path.as_ref())?;
Ok(Self { writer, level: 0 })
}
}
impl BackupCatalogWriter for SimpleCatalog {
fn start_directory(&mut self, name: &CStr) -> Result<(), Error> {
self.writer.write(&[CatalogEntryType::Directory as u8])?;
self.writer.write(name.to_bytes_with_nul())?;
self.writer.write(b"{")?;
self.level += 1;
Ok(())
}
fn end_directory(&mut self) -> Result<(), Error> {
if self.level == 0 {
bail!("got unexpected end_directory level 0");
}
self.writer.write(b"}")?;
self.level -= 1;
Ok(())
}
fn add_file(&mut self, name: &CStr, size: u64, mtime: u64) -> Result<(), Error> {
self.writer.write(&[CatalogEntryType::File as u8])?;
self.writer.write(&size.to_le_bytes())?;
self.writer.write(&mtime.to_le_bytes())?;
self.writer.write(name.to_bytes_with_nul())?;
Ok(())
}
fn add_symlink(&mut self, name: &CStr) -> Result<(), Error> {
self.writer.write(&[CatalogEntryType::Symlink as u8])?;
self.writer.write(name.to_bytes_with_nul())?;
Ok(())
}
fn add_hardlink(&mut self, name: &CStr) -> Result<(), Error> {
self.writer.write(&[CatalogEntryType::Hardlink as u8])?;
self.writer.write(name.to_bytes_with_nul())?;
Ok(())
}
fn add_block_device(&mut self, name: &CStr) -> Result<(), Error> {
self.writer.write(&[CatalogEntryType::BlockDevice as u8])?;
self.writer.write(name.to_bytes_with_nul())?;
Ok(())
}
fn add_char_device(&mut self, name: &CStr) -> Result<(), Error> {
self.writer.write(&[CatalogEntryType::CharDevice as u8])?;
self.writer.write(name.to_bytes_with_nul())?;
Ok(())
}
fn add_fifo(&mut self, name: &CStr) -> Result<(), Error> {
self.writer.write(&[CatalogEntryType::Fifo as u8])?;
self.writer.write(name.to_bytes_with_nul())?;
Ok(())
}
fn add_socket(&mut self, name: &CStr) -> Result<(), Error> {
self.writer.write(&[CatalogEntryType::Socket as u8])?;
self.writer.write(name.to_bytes_with_nul())?;
Ok(())
}
}
pub struct SimpleCatalogReader {
reader: BufReader<File>,
dir_stack: Vec<CString>,
}
impl SimpleCatalogReader {
pub fn open<P: AsRef<std::path::Path>>(path: P) -> Result<Self, Error> {
let file = std::fs::File::open(path)?;
let reader = BufReader::new(file);
let dir_stack = Vec::new();
Ok(Self { reader, dir_stack })
}
fn read_filename(&mut self) -> Result<std::ffi::CString, Error> {
let mut filename = Vec::new();
self.reader.read_until(0u8, &mut filename)?;
if filename.len() > 0 && filename[filename.len()-1] == 0u8 {
filename.pop();
}
if filename.len() == 0 {
bail!("got zero length filename");
}
if filename.iter().find(|b| **b == b'/').is_some() {
bail!("found invalid filename with slashes.");
}
Ok(unsafe { CString::from_vec_unchecked(filename) })
}
fn next_byte(&mut self) -> Result<u8, std::io::Error> {
let mut buf = [0u8; 1];
self.reader.read_exact(&mut buf)?;
Ok(buf[0])
}
fn expect_next(&mut self, expect: u8) -> Result<(), Error> {
let next = self.next_byte()?;
if next != expect {
bail!("got unexpected byte ({} != {})", next, expect);
}
Ok(())
}
fn print_entry(&self, etype: CatalogEntryType, filename: &CStr, size: u64, mtime: u64) -> Result<(), Error> {
let mut out = Vec::new();
write!(out, "{} ", char::from(etype as u8))?;
for name in &self.dir_stack {
out.extend(name.to_bytes());
out.push(b'/');
}
out.extend(filename.to_bytes());
let dt = Local.timestamp(mtime as i64, 0);
if etype == CatalogEntryType::File {
write!(out, " {} {}", size, dt.to_rfc3339_opts(chrono::SecondsFormat::Secs, false))?;
}
write!(out, "\n")?;
std::io::stdout().write_all(&out)?;
Ok(())
}
fn parse_entries(&mut self) -> Result<(), Error> {
loop {
let etype = match self.next_byte() {
Ok(v) => v,
Err(err) => {
if err.kind() == std::io::ErrorKind::UnexpectedEof {
if self.dir_stack.len() == 0 {
break;
}
}
return Err(err.into());
}
};
if etype == b'}' {
if self.dir_stack.pop().is_none() {
bail!("got unexpected '}'");
}
break;
}
let etype = CatalogEntryType::try_from(etype)?;
match etype {
CatalogEntryType::Directory => {
let filename = self.read_filename()?;
self.print_entry(etype.into(), &filename, 0, 0)?;
self.dir_stack.push(filename);
self.expect_next(b'{')?;
self.parse_entries()?;
}
CatalogEntryType::File => {
let size = unsafe { self.reader.read_le_value::<u64>()? };
let mtime = unsafe { self.reader.read_le_value::<u64>()? };
let filename = self.read_filename()?;
self.print_entry(etype.into(), &filename, size, mtime)?;
}
CatalogEntryType::Symlink |
CatalogEntryType::Hardlink |
CatalogEntryType::Fifo |
CatalogEntryType::Socket |
CatalogEntryType::BlockDevice |
CatalogEntryType::CharDevice => {
let filename = self.read_filename()?;
self.print_entry(etype.into(), &filename, 0, 0)?;
}
}
}
Ok(())
}
pub fn dump(&mut self) -> Result<(), Error> {
self.parse_entries()?;
Ok(())
}
}