refactor

src/main.rs

@@ -1,4 +1,4 @@
-use std::io::{Read,Seek};
+use std::io::Read;
 use clap::{Args,Parser,Subcommand};
 use anyhow::Result as AResult;
 use futures::StreamExt;
@@ -121,20 +121,17 @@ enum Cookie{
 	File(std::path::PathBuf),
 }
 
-enum ReaderType<'a,R:Read+Seek>{
-	GZip(flate2::read::GzDecoder<&'a mut R>),
-	Raw(&'a mut R),
+enum ReaderType<R:Read>{
+	GZip(flate2::read::GzDecoder<std::io::BufReader<R>>),
+	Raw(std::io::BufReader<R>),
 }
 
-fn maybe_gzip_decode<R:Read+Seek>(input:&mut R)->AResult<ReaderType<R>>{
-	let mut first_2=[0u8;2];
-	if let (Ok(()),Ok(()))=(std::io::Read::read_exact(input,&mut first_2),std::io::Seek::rewind(input)){
-		match &first_2{
-			b"\x1f\x8b"=>Ok(ReaderType::GZip(flate2::read::GzDecoder::new(input))),
-			_=>Ok(ReaderType::Raw(input)),
-		}
-	}else{
-		Err(anyhow::Error::msg("failed to peek"))
+fn maybe_gzip_decode<R:Read>(input:R)->AResult<ReaderType<R>>{
+	let mut buf=std::io::BufReader::new(input);
+	let peek=std::io::BufRead::fill_buf(&mut buf)?;
+	match &peek[0..2]{
+		b"\x1f\x8b"=>Ok(ReaderType::GZip(flate2::read::GzDecoder::new(buf))),
+		_=>Ok(ReaderType::Raw(buf)),
 	}
 }
 
@@ -268,7 +265,7 @@ async fn get_version_history(client:&reqwest::Client,cookie:&str,asset_id:AssetI
 	Ok(asset_list)
 }
 
-async fn download_asset_version(client:&reqwest::Client,cookie:&str,asset_id_str:&str,asset_version_str:&str)->AResult<impl Read+Seek>{
+async fn download_asset_version(client:&reqwest::Client,cookie:&str,asset_id_str:&str,asset_version_str:&str)->AResult<reqwest::Response>{
 	let mut url=reqwest::Url::parse("https://assetdelivery.roblox.com/v1/asset/")?;
 	//url borrow scope
 	{
@@ -287,7 +284,7 @@ async fn download_asset_version(client:&reqwest::Client,cookie:&str,asset_id_str
 			continue;
 		}
 
-		return Ok(std::io::Cursor::new(resp.bytes().await?));
+		return Ok(resp);
 	}
 	Err(anyhow::Error::msg("all requests failed"))
 }
@@ -316,9 +313,8 @@ async fn download_history(config:DownloadHistoryConfig)->AResult<()>{
 		let asset_id_str=asset_id_string.as_str();
 		let output_folder=config.output_folder.clone();
 		async move{
-			let mut readable=download_asset_version(client,cookie,asset_id_str,asset_version.assetVersionNumber.to_string().as_str()).await?;
-
-			let contents=match maybe_gzip_decode(&mut readable)?{
+			let resp=download_asset_version(client,cookie,asset_id_str,asset_version.assetVersionNumber.to_string().as_str()).await?;
+			let contents=match maybe_gzip_decode(std::io::Cursor::new(resp.bytes().await?))?{
 				ReaderType::GZip(readable)=>read_readable(readable)?,
 				ReaderType::Raw(readable)=>read_readable(readable)?,
 			};
@@ -344,21 +340,18 @@ async fn download_history(config:DownloadHistoryConfig)->AResult<()>{
 	Ok(())
 }
 
-fn load_dom<R:Read+Seek>(input:&mut R)->AResult<rbx_dom_weak::WeakDom>{
-	let mut first_8=[0u8;8];
-	if let (Ok(()),Ok(()))=(std::io::Read::read_exact(input, &mut first_8),std::io::Seek::rewind(input)){
-		match &first_8[0..4]{
-			b"<rob"=>{
-				match &first_8[4..8]{
-					b"lox!"=>return rbx_binary::from_reader(input).map_err(anyhow::Error::msg),
-					b"lox "=>return rbx_xml::from_reader(input,rbx_xml::DecodeOptions::default()).map_err(anyhow::Error::msg),
-					other=>Err(anyhow::Error::msg(format!("Unknown Roblox file type {:?}",other))),
-				}
-			},
-			_=>Err(anyhow::Error::msg("unsupported file type")),
-		}
-	}else{
-		Err(anyhow::Error::msg("peek failed"))
+fn load_dom<R:Read>(input:R)->AResult<rbx_dom_weak::WeakDom>{
+	let mut buf=std::io::BufReader::new(input);
+	let peek=std::io::BufRead::fill_buf(&mut buf)?;
+	match &peek[0..4]{
+		b"<rob"=>{
+			match &peek[4..8]{
+				b"lox!"=>return rbx_binary::from_reader(buf).map_err(anyhow::Error::msg),
+				b"lox "=>return rbx_xml::from_reader_default(buf).map_err(anyhow::Error::msg),
+				other=>Err(anyhow::Error::msg(format!("Unknown Roblox file type {:?}",other))),
+			}
+		},
+		_=>Err(anyhow::Error::msg("unsupported file type")),
 	}
 }
 
@@ -451,8 +444,8 @@ struct DecompiledContext{
 	tree_refs:std::collections::HashMap<rbx_dom_weak::types::Ref,TreeNode>,
 }
 
-fn generate_decompiled_context<R:Read+Seek>(mut input:R)->AResult<DecompiledContext>{
-	let dom=load_dom(&mut input)?;
+fn generate_decompiled_context<R:Read>(input:R)->AResult<DecompiledContext>{
+	let dom=load_dom(input)?;
 
 	let mut tree_refs=std::collections::HashMap::new();
 	tree_refs.insert(dom.root_ref(),TreeNode::new(