more abstraction around unityfs to read multiple files from a single reader

1 files changed, 0 insertions, 327 deletions

diff --git a/src/unityfs.rs b/src/unityfs.rs
deleted file mode 100644
index 05ad922..0000000
--- a/src/unityfs.rs
+++ /dev/null
@@ -1,327 +0,0 @@
-use crate::helper::{AlignExt, ReadExt};
-use anyhow::{Result, anyhow, bail};
-use humansize::DECIMAL;
-use log::{debug, info, trace};
-use std::io::{Cursor, Error, ErrorKind, Read, Seek, SeekFrom};
-
-pub struct UnityFS<T> {
-    nodes: Vec<NodeInfo>,
-    reader: BlocksReader<T>,
-    pub file_version: u32,
-    pub player_version: String,
-    pub unity_version: String,
-}
-
-#[derive(Debug, Clone)]
-pub struct NodeInfo {
-    pub name: String,
-    pub size: u64,
-    offset: u64,
-    _status: u32,
-}
-
-struct BlockInfo {
-    comp_size: u32,
-    decomp_size: u32,
-    comp_scheme: CompressionScheme,
-}
-
-pub struct NodeReader<'a, T> {
-    inner: &'a mut BlocksReader<T>,
-    position: u64,
-    offset: u64,
-    size: u64,
-}
-
-impl<T: Read + Seek> UnityFS<T> {
-    pub fn open(mut file: T) -> Result<Self> {
-        let signature = file.read_cstr()?;
-        if signature.as_str() != "UnityFS" {
-            bail!("unknown signature {signature:?}")
-        }
-
-        let file_version = file.read_u32_be()?;
-        let player_version = file.read_cstr()?;
-        let unity_version = file.read_cstr()?;
-        let size = file.read_u64_be()?;
-        let blockindex_comp_size = file.read_u32_be()?;
-        let blockindex_decomp_size = file.read_u32_be()?;
-        let flags = file.read_u32_be()?;
-
-        let meta_comp_scheme = CompressionScheme::from_flag_num(flags as u8).ok_or(anyhow!(
-            "unknown block compression 0x{:02x}",
-            (flags & 0x3f) as u8
-        ))?;
-        let blockindex_eof = flags & 0x80 != 0;
-        let blockindex_has_directory = flags & 0x40 != 0;
-        let blockindex_need_padding = flags & 0x200 != 0;
-
-        info!("File Version: {file_version:?}");
-        info!("Player Version: {player_version:?}");
-        info!("Unity Version: {unity_version:?}");
-        debug!("size={size:?}");
-        debug!("meta_comp_size={blockindex_comp_size:?}");
-        debug!("meta_decomp_size={blockindex_decomp_size:?}");
-        debug!("flags={flags:?}");
-        debug!("meta_comp_scheme={meta_comp_scheme:?}");
-        debug!("blockindex_eof={blockindex_eof:?}");
-        debug!("blockindex_has_directory={blockindex_has_directory:?}");
-        debug!("blockindex_need_padding={blockindex_need_padding:?}");
-
-        let mut blockindex = {
-            let restore_position = if blockindex_eof {
-                let pos = file.stream_position()?;
-                file.seek(SeekFrom::End(-(blockindex_comp_size as i64)))?;
-                Some(pos)
-            } else {
-                None
-            };
-
-            let mut blockindex = vec![0u8; blockindex_comp_size as usize];
-            file.read_exact(&mut blockindex)?;
-
-            if let Some(pos) = restore_position {
-                file.seek(SeekFrom::Start(pos))?;
-            }
-            let blockindex =
-                meta_comp_scheme.decompress(blockindex, blockindex_decomp_size as usize)?;
-            Cursor::new(blockindex)
-        };
-
-        file.align(16)?;
-
-        blockindex.read_u128_be()?;
-
-        let num_blocks = blockindex.read_u32_be()?;
-        info!("File has {num_blocks} blocks");
-        let mut blocks = Vec::new();
-        for _ in 0..num_blocks {
-            let decomp_size = blockindex.read_u32_be()?;
-            let comp_size = blockindex.read_u32_be()?;
-            let flags = blockindex.read_u16_be()?;
-            let comp_scheme = CompressionScheme::from_flag_num(flags as u8)
-                .ok_or(anyhow!("unknown block compression 0x{:02x}", flags & 0x3f))?;
-            blocks.push(BlockInfo {
-                comp_size,
-                decomp_size,
-                comp_scheme,
-            })
-        }
-
-        let num_nodes = blockindex.read_u32_be()?;
-        debug!("num_nodes={num_nodes:?}");
-        let mut nodes = Vec::new();
-        for _ in 0..num_nodes {
-            let offset = blockindex.read_u64_be()?;
-            let size = blockindex.read_u64_be()?;
-            let status = blockindex.read_u32_be()?;
-            let name = blockindex.read_cstr()?;
-            info!(
-                "found node {name:?} (size={}, status={status})",
-                humansize::format_size(size, DECIMAL)
-            );
-            nodes.push(NodeInfo {
-                offset,
-                size,
-                _status: status,
-                name,
-            })
-        }
-
-        let position = file.stream_position()?;
-
-        Ok(Self {
-            file_version,
-            player_version,
-            unity_version,
-            nodes,
-            reader: BlocksReader::new(blocks, file, position),
-        })
-    }
-
-    pub fn nodes(&self) -> &[NodeInfo] {
-        &self.nodes
-    }
-
-    pub fn find_main_file(&self) -> Option<&NodeInfo> {
-        self.nodes().iter().find(|n| {
-            !n.name.ends_with(".resource")
-                && !n.name.ends_with(".resS")
-                && !n.name.ends_with(".sharedAssets")
-        })
-    }
-
-    pub fn read<'a>(&'a mut self, node: &NodeInfo) -> std::io::Result<NodeReader<'a, T>> {
-        self.reader.seek(SeekFrom::Start(node.offset))?;
-        Ok(NodeReader {
-            size: node.size,
-            offset: node.offset,
-            position: 0,
-            inner: &mut self.reader,
-        })
-    }
-}
-
-struct BlocksReader<T> {
-    blocks: Vec<BlockInfo>,
-    inner: T,
-    inner_seek_offset: u64,
-    nblock_index: usize,
-    cblock_data: Vec<u8>,
-    cblock_off: usize,
-}
-impl<T: Read> BlocksReader<T> {
-    pub fn new(blocks: Vec<BlockInfo>, inner: T, inner_seek_offset: u64) -> Self {
-        Self {
-            blocks,
-            inner,
-            inner_seek_offset,
-            nblock_index: 0,
-            cblock_data: Vec::new(),
-            cblock_off: 0,
-        }
-    }
-    pub fn load_next_block(&mut self) -> std::io::Result<()> {
-        trace!("loading block {}", self.nblock_index);
-        let block = &self.blocks[self.nblock_index];
-        let mut comp_buf = vec![0; block.comp_size as usize];
-        self.inner.read_exact(&mut comp_buf)?;
-        let decomp_buf = block
-            .comp_scheme
-            .decompress(comp_buf, block.decomp_size as usize)
-            .map_err(|e| {
-                std::io::Error::new(
-                    ErrorKind::InvalidData,
-                    format!("decompression failure: {e}"),
-                )
-            })?;
-        self.nblock_index += 1;
-        self.cblock_data = decomp_buf;
-        self.cblock_off = 0;
-        Ok(())
-    }
-}
-impl<T: Read> Read for BlocksReader<T> {
-    fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
-        if self.cblock_off >= self.cblock_data.len() {
-            self.load_next_block()?;
-        }
-        let size = (self.cblock_data.len() - self.cblock_off).min(buf.len());
-        buf[..size].copy_from_slice(&self.cblock_data[self.cblock_off..self.cblock_off + size]);
-        self.cblock_off += size;
-        Ok(size)
-    }
-}
-impl<T: Seek + Read> Seek for BlocksReader<T> {
-    fn seek(&mut self, pos: SeekFrom) -> std::io::Result<u64> {
-        let SeekFrom::Start(pos) = pos else {
-            unimplemented!()
-        };
-        debug!("seek decomp to {pos}");
-        let mut comp_off = self.inner_seek_offset;
-        let mut decomp_off = 0;
-        let mut target_block = None;
-        for (i, b) in self.blocks.iter().enumerate() {
-            if pos <= decomp_off + b.decomp_size as u64 {
-                target_block = Some(i);
-                break;
-            }
-            decomp_off += b.decomp_size as u64;
-            comp_off += b.comp_size as u64;
-        }
-
-        let Some(i) = target_block else {
-            return Err(std::io::Error::new(
-                ErrorKind::UnexpectedEof,
-                "seek out of bounds",
-            ));
-        };
-
-        let block_off = pos - decomp_off;
-        debug!("target is block={i} offset={block_off}");
-        if self.nblock_index == i + 1 {
-            debug!("intra-block seek")
-        } else {
-            debug!("seek comp to {comp_off}");
-            self.inner.seek(SeekFrom::Start(comp_off))?;
-            self.nblock_index = i;
-            self.load_next_block()?;
-        }
-        self.cblock_off = block_off as usize;
-
-        Ok(pos)
-    }
-}
-
-impl<T: Read> Read for NodeReader<'_, T> {
-    fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
-        let bytes_left = self.size - self.position;
-        let end = buf.len().min(bytes_left as usize);
-        let size = self.inner.read(&mut buf[..end])?;
-        self.position += size as u64;
-        Ok(size)
-    }
-}
-impl<T: Seek + Read> Seek for NodeReader<'_, T> {
-    fn seek(&mut self, pos: SeekFrom) -> std::io::Result<u64> {
-        match pos {
-            SeekFrom::Current(n) if n >= 0 => {
-                for _ in 0..n {
-                    self.read_exact(&mut [0u8])?;
-                }
-                Ok(self.stream_position()?)
-            }
-            SeekFrom::Start(n) => {
-                debug!("seek node to {n} (off={})", self.offset);
-                if n > self.size {
-                    return Err(Error::new(ErrorKind::NotSeekable, "seek out of bounds"));
-                }
-                self.position = n;
-                self.inner.seek(SeekFrom::Start(self.offset + n))
-            }
-            _ => unimplemented!(),
-        }
-    }
-    fn stream_position(&mut self) -> std::io::Result<u64> {
-        Ok(self.position)
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq)]
-enum CompressionScheme {
-    None,
-    Lzma,
-    Lz4,
-    Lz4hc,
-    Lzham,
-}
-impl CompressionScheme {
-    pub fn from_flag_num(n: u8) -> Option<CompressionScheme> {
-        Some(match n & 0x3f {
-            0 => CompressionScheme::None,
-            1 => CompressionScheme::Lzma,
-            2 => CompressionScheme::Lz4,
-            3 => CompressionScheme::Lz4hc,
-            4 => CompressionScheme::Lzham,
-            _ => return None,
-        })
-    }
-    pub fn decompress(&self, block: Vec<u8>, decomp_size: usize) -> Result<Vec<u8>> {
-        match self {
-            CompressionScheme::None => Ok(block),
-            CompressionScheme::Lzma => {
-                let mut r = lzma::Reader::from(Cursor::new(block))?;
-                let mut buf = Vec::new();
-                r.read_to_end(&mut buf)?;
-                Ok(buf)
-            }
-            CompressionScheme::Lz4hc | CompressionScheme::Lz4 => {
-                Ok(lz4_flex::block::decompress(&block, decomp_size)?)
-            }
-            // CompressionScheme::LZ4HC | CompressionScheme::LZ4 => {
-            //     Ok(lz4::block::decompress(&block, Some(decomp_size as i32))?)
-            // }
-            CompressionScheme::Lzham => todo!(),
-        }
-    }
-}