mstar: further code optimizations + lzop optimization. fix memory issue by writing directly to file

src/formats/mstar.rs

@@ -5,12 +5,12 @@ use lz4::block::decompress;
 use lzma_rs::lzma_decompress;
 
 use crate::common;
-use crate::utils::lzop::{decompress_lzop};
+use crate::utils::lzop::{unlzop_to_file};
 use crate::utils::sparse::{unsparse_to_file};
 
 //change whether the "userdata" partition is skipped
-// this is because the userdata partition is sometimes enourmous sizes like 27gb, and it will fail to allocate memory on most computers
-// if you want to attempt to extract "userdata" you can enable the option
+// this is because the userdata partition is sometimes enourmous sizes like 27gb, and it is empty anyways
+// if you want to extract "userdata" you can disable the option
 static CONFIG_SKIP_USERDATA: bool = true;
 
 pub fn is_mstar_file(file: &File) -> bool {
@@ -76,13 +76,9 @@ pub fn extract_mstar(file: &File, output_folder: &str) -> Result<(), Box<dyn std
     let lines: Vec<&str> = script_string.lines().map(|l| l.trim()).collect();
     let mut i = 0;
 
-    while i < lines.len() {
-        let line = lines[i];
-
+    for line in &lines {
         if line.starts_with("filepartload") {
             let parts: Vec<&str> = line.split_whitespace().collect();
-
-            if parts.len() >= 5 {
             let offset = parse_number(parts[3]).unwrap_or(0);
             let size = parse_number(parts[4]).unwrap_or(0);
 
@@ -93,7 +89,6 @@ pub fn extract_mstar(file: &File, output_folder: &str) -> Result<(), Box<dyn std
             //    "unknown"
             //};
             let mut partname = "unknown";
-
             let mut compression = "none";
             let mut lz4_expect_size = 0;
             let mut j = i + 1;
@@ -173,30 +168,26 @@ pub fn extract_mstar(file: &File, output_folder: &str) -> Result<(), Box<dyn std
                     out_data = decompress_lz4(&data, lz4_expect_size.try_into().unwrap())?;
                 } else if compression == "lzo" {
                     println!("- Decompessing LZO..");
-                        out_data = decompress_lzop(&data)?;
+                    unlzop_to_file(&data, output_path)?;
+                    println!("-- Saved file!");
+                    i += 1;
+                    continue
                 } else if compression == "sparse" {
                     println!("- Unsparsing...");
                     unsparse_to_file(&data, output_path)?;
                     println!("-- Saved file!");
                     i += 1;
                     continue
-                        //out_data = unsparse(&data)?;
                 } else {
                     out_data = data;
                 }
 
                 fs::create_dir_all(&output_folder)?;
-                    let mut out_file = OpenOptions::new()
-                        .append(true)
-                        .create(true)
-                        .open(output_path)?;
-
+                let mut out_file = OpenOptions::new().append(true).create(true).open(output_path)?;
                 out_file.write_all(&out_data)?;
-
                 println!("-- Saved file!");
             }
         }
-        }
 
         i += 1;
     }

src/utils/lzop.rs

@@ -1,5 +1,7 @@
 use binrw::{BinRead, BinReaderExt};
-use std::io::{Cursor};
+use std::fs::OpenOptions;
+use std::path::{PathBuf};
+use std::io::{Cursor, Write};
 
 use simd_adler32::adler32;
 use crate::common;
@@ -28,7 +30,7 @@ struct SegmentHeader {
     checksum: u32,
 }
 
-pub fn decompress_lzop(data: &[u8]) -> Result<Vec<u8>, Box<dyn std::error::Error>> {
+pub fn unlzop_to_file(data: &[u8], file_path: PathBuf) -> Result<(), Box<dyn std::error::Error>> {
     let mut data_reader = Cursor::new(data);
     let header: LzopHeader = data_reader.read_be()?;
     if header.magic_bytes != b"\x89LZO\x00\x0D\x0A\x1A\x0A" {
@@ -39,7 +41,7 @@ pub fn decompress_lzop(data: &[u8]) -> Result<Vec<u8>, Box<dyn std::error::Error
     }
 
     let lzo = minilzo_rs::LZO::init()?;
-    let mut decompressed_output = Vec::new();
+    let mut out_file = OpenOptions::new().create(true).append(true).open(file_path)?;
     loop {
         if (data.len() as u64 - data_reader.position()) < 12 { //check if there are enough bytes to read a segment header
             break;
@@ -66,8 +68,8 @@ pub fn decompress_lzop(data: &[u8]) -> Result<Vec<u8>, Box<dyn std::error::Error
             return Err("Invalid segment checksum! Data corrupted?".into());
         };
 
-        decompressed_output.extend_from_slice(&out_data);
+        out_file.write_all(&out_data)?;
     }
 
-    Ok(decompressed_output)
+    Ok(())
 }