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104 lines
3.7 KiB
Rust

use crate::format::gzip::GZipFormat;
use crate::format::xz::XZFormat;
use crate::format::{FileFormat, FileObject};
use crate::utils::xz_decoder::XzDecoder;
use anyhow::{bail, Context};
use libflate::gzip;
use std::fs::File;
use std::io::{BufReader, BufWriter, Read, Write};
use std::path::Path;
use std::{fs, io};
use tar::{Archive, EntryType};
const TAR_HEADER: &[u8] = &[0x75, 0x73, 0x74, 0x61, 0x72];
pub enum TarFormat {
Xz,
Gz,
Uncompressed,
}
impl FileFormat for TarFormat {
fn parse(file: &FileObject) -> anyhow::Result<Self> {
if file.header.starts_with(TAR_HEADER) {
tracing::info!("Detected uncompressed tar file");
Ok(Self::Uncompressed)
} else if file.ext.contains(".tar.") {
if let Ok(_xz) = XZFormat::parse(file) {
tracing::info!("Detected tar file compressed with xz");
Ok(Self::Xz)
} else if let Ok(_gz) = GZipFormat::parse(file) {
tracing::info!("Detected tarfile compressed with gz");
Ok(Self::Gz)
} else {
bail!("Not a tar file or a tar with unknown compression");
}
} else if file.ext.ends_with(".tar") {
tracing::info!("Assuming tar based on the file extension");
Ok(Self::Uncompressed)
} else {
bail!("Not a tar file");
}
}
fn extract(&self, file: &Path, output: &Path) -> anyhow::Result<()> {
let mut reader = BufReader::new(File::open(file).context("Opening input")?);
match self {
TarFormat::Xz => {
let mut decoder = XzDecoder::new(reader);
extract_tar(&mut decoder, output)
}
TarFormat::Gz => {
let mut decoder = gzip::Decoder::new(&mut reader).context("Creating decoder")?;
extract_tar(&mut decoder, output)
}
TarFormat::Uncompressed => extract_tar(&mut reader, output).context("Extract tar"),
}
}
}
/// Extracts a tar file to the given output directory
fn extract_tar<R: Read>(reader: &mut R, output: &Path) -> anyhow::Result<()> {
if output.is_file() {
bail!("The output must be a directory.");
}
let mut archive = Archive::new(reader);
for file in archive.entries().context("Reading tar entries")? {
let mut file = file.context("Retrieving tar file entry")?;
let header = file.header();
let file_path = header.path().context("Retrieving path of file")?;
let output_path = output.join(file_path);
match header.entry_type() {
EntryType::Regular => {
if let Some(parent) = output_path.parent() {
if !parent.exists() {
tracing::debug!("Creating parent path {parent:?}");
fs::create_dir_all(parent)?;
}
}
tracing::debug!("Decompressing entry to {output_path:?}");
let mut output_file = BufWriter::new(
File::create(&output_path)
.with_context(|| format!("Create output file {output_path:?}"))?,
);
io::copy(&mut file, &mut output_file).context("writing tar entry to output")?;
output_file.flush()?;
}
EntryType::Directory => {
tracing::debug!("Creating output directory {output_path:?}");
fs::create_dir_all(&output_path)
.with_context(|| format!("Failed to create output directory {output_path:?}"))?
}
other => {
tracing::debug!("Ignoring entry of type {other:?}");
}
}
}
Ok(())
}