Add support to read embbed control block (tested game: https://vndb.org/v19829 )

msg_tool_build/.gitignore

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+Cargo.lock
+target/

msg_tool_build/Cargo.toml

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+[package]
+name = "msg_tool_build"
+version = "0.3.1"
+edition = "2024"
+repository = "https://github.com/lifegpc/msg-tool"
+description = "Build time library for the msg-tool project."
+license = "GPL-3.0-or-later"
+
+[dependencies]
+json = { version = "0.12", optional = true }
+zstd = { version = "0.13", optional = true }
+
+[features]
+kirikiri-arc = ["json", "simple-pack"]
+simple-pack = ["zstd"]
+
+[package.metadata.docs.rs]
+all-features = true

msg_tool_build/src/kr_arc.rs

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+use crate::simple_pack::SimplePack;
+use std::path::Path;
+
+/// Pack all binary files in cx_cb into a single archive.
+pub fn gen_cx_cb<P: AsRef<Path> + ?Sized, D: AsRef<Path> + ?Sized>(
+    json_path: &P,
+    outdir: &D,
+    level: i32,
+) -> std::io::Result<()> {
+    let p = json_path.as_ref();
+    let pb = p
+        .parent()
+        .unwrap_or_else(|| Path::new(""))
+        .join("crypt")
+        .join("cx_cb");
+    let json_data = std::fs::read_to_string(p)?;
+    let json = json::parse(&json_data)
+        .map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidData, e))?;
+    let mut pack = SimplePack::new(&outdir.as_ref().join("cx_cb.pck"))?;
+    for (_, obj) in json.entries() {
+        if let Some(name) = obj["ControlBlockName"].as_str() {
+            let file_path = pb.join(name);
+            if !file_path.exists() {
+                return Err(std::io::Error::new(
+                    std::io::ErrorKind::NotFound,
+                    format!("File not found: {}", file_path.display()),
+                ));
+            }
+            let file = std::fs::File::open(file_path)?;
+            let file = std::io::BufReader::new(file);
+            pack.add_file(name, file)?;
+        }
+    }
+    if level >= 0 && level <= 22 {
+        pack.compress(level)?;
+    }
+    Ok(())
+}

msg_tool_build/src/lib.rs

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+#[cfg(feature = "kirikiri-arc")]
+pub mod kr_arc;
+#[cfg(feature = "simple-pack")]
+mod simple_pack;

msg_tool_build/src/simple_pack.rs

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+//! A simple implementation of a pack file
+use std::fs::File;
+use std::io::{BufWriter, Read, Result, Seek, Write};
+use std::path::{Path, PathBuf};
+
+pub struct SimplePack {
+    file: File,
+    path: PathBuf,
+    tmp_path: PathBuf,
+}
+
+impl SimplePack {
+    pub fn new<P: AsRef<Path> + ?Sized>(path: &P) -> Result<Self> {
+        let mut file = File::create(path.as_ref())?;
+        file.write_all(b"SPCK")?;
+        file.write_all(&[0])?; // No compression
+        Ok(Self {
+            file,
+            path: path.as_ref().to_path_buf(),
+            tmp_path: path.as_ref().with_added_extension(".tmp"),
+        })
+    }
+    pub fn add_file<R: Read>(&mut self, name: &str, mut data: R) -> Result<()> {
+        let mut writer = BufWriter::new(&mut self.file);
+        writer.write_all(name.as_bytes())?;
+        writer.write_all(&[0])?; // Null terminator for the name
+        let file_size_loc = writer.stream_position()?;
+        writer.write_all(&0u64.to_le_bytes())?; // Placeholder for file size
+        let size = std::io::copy(&mut data, &mut writer)?;
+        let current_pos = writer.stream_position()?;
+        writer.seek(std::io::SeekFrom::Start(file_size_loc))?;
+        writer.write_all(&size.to_le_bytes())?; // Write the actual file size
+        writer.seek(std::io::SeekFrom::Start(current_pos))?; // Move back to the end of the file
+        writer.flush()?;
+        Ok(())
+    }
+    pub fn compress(mut self, level: i32) -> Result<()> {
+        self.file.flush()?;
+        std::mem::drop(self.file); // Close the file before renaming
+        // Move the file to a temporary location
+        std::fs::rename(&self.path, &self.tmp_path)?;
+        {
+            let tmp_file = File::open(&self.tmp_path)?;
+            let mut reader = std::io::BufReader::new(tmp_file);
+            reader.seek_relative(5)?; // Skip header
+            let original_size = reader.get_ref().metadata()?.len() - 5;
+            let outfile = File::create(&self.path)?;
+            let mut writer = std::io::BufWriter::new(outfile);
+            writer.write_all(b"SPCK")?;
+            writer.write_all(&[1])?; // Compression flag
+            let compress_size_loc = writer.stream_position()?;
+            writer.write_all(&0u64.to_le_bytes())?; // Placeholder for compressed size
+            writer.write_all(&original_size.to_le_bytes())?;
+            let cur_loc = writer.stream_position()?;
+            let mut encoder = zstd::stream::write::Encoder::new(&mut writer, level)?;
+            std::io::copy(&mut reader, &mut encoder)?;
+            encoder.finish()?;
+            writer.flush()?;
+            let compressed_size = writer.stream_position()? - cur_loc;
+            writer.seek(std::io::SeekFrom::Start(compress_size_loc))?;
+            writer.write_all(&compressed_size.to_le_bytes())?; // Write the actual compressed size
+        }
+        std::fs::remove_file(&self.tmp_path)?; // Clean up the temporary file
+        Ok(())
+    }
+}