Make jaby_engine_fconv output lz4 files on request

src/Tools/jaby_engine_fconv/src/main.rs

@@ -6,6 +6,9 @@ use tool_helper::Error;
 #[derive(Parser)]
 #[clap(about = "Converts files to various JabyEngine related file formats", long_about = None)]
 struct CommandLine {
+    #[clap(long="lz4", default_value_t=false)]
+    compress_lz4: bool,
+
     #[clap(short='o')]
     output_file: Option<PathBuf>,
 
@@ -24,14 +27,42 @@ enum SubCommands {
 fn run_main() -> Result<(), Error> {
     match CommandLine::try_parse() {
         Ok(cmd) => {
-            let input  = tool_helper::open_input(cmd.input_file)?;
-            let output = tool_helper::open_output(cmd.output_file)?;
+            let     input        = tool_helper::open_input(cmd.input_file)?;
+            let mut buffer      = Vec::<u8>::new();
+            let mut output_file = tool_helper::open_output(cmd.output_file)?;
+            let     dst_buffer  = {
+                if cmd.compress_lz4 {
+                    &mut buffer as &mut dyn std::io::Write
+                }
+
+                else {
+                    &mut output_file as &mut dyn std::io::Write
+                }
+            };
 
             match cmd.sub_command {
-                SubCommands::SimpleTIM(args) => reduced_tim::convert(args, input, output),
+                SubCommands::SimpleTIM(args) => {
+                    reduced_tim::convert(args, input, dst_buffer)?;
+                }
             }
+
+            // We encoded the file to a temporary buffer and now need to write it
+            if cmd.compress_lz4 {
+                println!("Buffer-Size: {} ({} Sectors)", buffer.len(), (buffer.len() + 2047)/2048);
+                let buffer = tool_helper::compress::lz4(&buffer, 16)?;
+                println!("New buffer-Size: {} ({} Sectors)", buffer.len(), (buffer.len() + 2047)/2048);
+
+                output_file.write(&buffer)?;
+            }
+
+            Ok(())
         },
-        Err(error) => Err(Error::from_error(error))
+        Err(error) => Err({
+                let mut error = Error::from_error(error);
+
+                error.exit_code = 0;
+                error
+            })
     }    
 }