From 8b3f655dc2abd75997c1791d557a2d5262c468ea Mon Sep 17 00:00:00 2001
From: Luke Street <luke.street@encounterpc.com>
Date: Wed, 2 Feb 2022 17:42:34 -0500
Subject: [PATCH] Various updates

- Use thiserror for nod::Error
- Use anyhow for error context chaining
- Stream logic fixes
---
 Cargo.toml      |  4 +++-
 src/disc/mod.rs |  4 ++--
 src/io/iso.rs   |  2 +-
 src/io/mod.rs   |  4 ++--
 src/lib.rs      | 24 +++++++++++-------------
 src/streams.rs  | 16 ++++++++++++++--
 6 files changed, 33 insertions(+), 21 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 2744fec..3dc3a1a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "nod"
-version = "0.1.1"
+version = "0.1.2"
 edition = "2018"
 authors = ["Luke Street <luke@street.dev>"]
 license = "MIT OR Apache-2.0"
@@ -19,9 +19,11 @@ path = "src/bin.rs"
 
 [dependencies]
 aes = "0.7.4"
+anyhow = "1.0.53"
 binread = "2.1.1"
 block-modes = "0.8.1"
 clap = "2.33.3"
 encoding_rs = "0.8.28"
 file-size = "1.0.3"
 sha-1 = "0.9.7"
+thiserror = "1.0.30"
diff --git a/src/disc/mod.rs b/src/disc/mod.rs
index 287d768..a21c13b 100644
--- a/src/disc/mod.rs
+++ b/src/disc/mod.rs
@@ -73,7 +73,7 @@ pub(crate) struct BI2Header {
 pub(crate) const BUFFER_SIZE: usize = 0x8000;
 
 /// Contains a disc's header & partition information.
-pub trait DiscBase {
+pub trait DiscBase: Send + Sync {
     /// Retrieves the disc's header.
     fn get_header(&self) -> &Header;
 
@@ -157,7 +157,7 @@ pub trait PartReadStream: ReadStream {
 }
 
 /// Disc partition header with file system table.
-pub trait PartHeader: Debug {
+pub trait PartHeader: Debug + Send + Sync {
     /// The root node for the filesystem.
     fn root_node(&self) -> &NodeType;
 
diff --git a/src/io/iso.rs b/src/io/iso.rs
index 6a4a21a..a8b163a 100644
--- a/src/io/iso.rs
+++ b/src/io/iso.rs
@@ -39,7 +39,7 @@ impl<T: ReadStream + Sized> DiscIOISOStream<T> {
     }
 }
 
-impl<T: ReadStream + Sized> DiscIO for DiscIOISOStream<T> {
+impl<T: ReadStream + Sized + Send + Sync> DiscIO for DiscIOISOStream<T> {
     fn begin_read_stream<'a>(&'a mut self, offset: u64) -> io::Result<Box<dyn ReadStream + 'a>> {
         let size = self.stream.stable_stream_len()?;
         let mut stream = self.stream.new_window(0, size)?;
diff --git a/src/io/mod.rs b/src/io/mod.rs
index d534590..c92f1c4 100644
--- a/src/io/mod.rs
+++ b/src/io/mod.rs
@@ -15,7 +15,7 @@ pub(crate) mod iso;
 pub(crate) mod nfs;
 
 /// Abstraction over supported disc file types.
-pub trait DiscIO {
+pub trait DiscIO: Send + Sync {
     /// Opens a new read stream for the disc file(s).
     /// Generally does _not_ need to be used directly.
     fn begin_read_stream(&mut self, offset: u64) -> io::Result<Box<dyn ReadStream + '_>>;
@@ -73,7 +73,7 @@ pub fn new_disc_io_from_buf(buf: &[u8]) -> Result<Box<dyn DiscIO + '_>> {
     Ok(Box::from(DiscIOISOStream::new(ByteReadStream { bytes: buf, position: 0 })?))
 }
 
-pub fn new_disc_io_from_stream<'a, T: 'a + ReadStream + Sized>(
+pub fn new_disc_io_from_stream<'a, T: 'a + ReadStream + Sized + Send + Sync>(
     stream: T,
 ) -> Result<Box<dyn DiscIO + 'a>> {
     Ok(Box::from(DiscIOISOStream::new(stream)?))
diff --git a/src/lib.rs b/src/lib.rs
index c8e3eb8..97a41d4 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -26,33 +26,31 @@
 //!     println!(s);
 //! }
 //! ```
+use thiserror::Error;
+
 pub mod disc;
 pub mod fst;
 pub mod io;
 pub mod streams;
 
-#[derive(Debug)]
+#[derive(Error, Debug)]
 pub enum Error {
-    BinaryFormat(binread::Error),
-    Encryption(block_modes::BlockModeError),
-    Io(String, std::io::Error),
+    #[error("binary format")]
+    BinaryFormat(#[from] binread::Error),
+    #[error("encryption")]
+    Encryption(#[from] block_modes::BlockModeError),
+    #[error("io error: `{0}`")]
+    Io(String, #[source] std::io::Error),
+    #[error("disc format error: `{0}`")]
     DiscFormat(String),
 }
 
-pub type Result<T> = std::result::Result<T, Error>;
+pub type Result<T> = anyhow::Result<T, Error>;
 
 impl From<std::io::Error> for Error {
     fn from(v: std::io::Error) -> Self { Error::Io("I/O error".to_string(), v) }
 }
 
-impl From<binread::Error> for Error {
-    fn from(v: binread::Error) -> Self { Error::BinaryFormat(v) }
-}
-
-impl From<block_modes::BlockModeError> for Error {
-    fn from(v: block_modes::BlockModeError) -> Self { Error::Encryption(v) }
-}
-
 #[inline(always)]
 pub(crate) fn div_rem<T: std::ops::Div<Output = T> + std::ops::Rem<Output = T> + Copy>(
     x: T,
diff --git a/src/streams.rs b/src/streams.rs
index 1f6871e..c5b873c 100644
--- a/src/streams.rs
+++ b/src/streams.rs
@@ -57,7 +57,14 @@ impl ReadStream for File {
         let before = self.stream_position()?;
         let result = self.seek(SeekFrom::End(0));
         // Try to restore position even if the above failed
-        self.seek(SeekFrom::Start(before))?;
+        let seek_result = self.seek(SeekFrom::Start(before));
+        if seek_result.is_err() {
+            return if result.is_err() {
+                result
+            } else {
+                seek_result
+            }
+        }
         result
     }
 
@@ -104,6 +111,9 @@ impl<'a> SharedWindowedReadStream<'a> {
 fn windowed_read(stream: &mut dyn WindowedReadStream, buf: &mut [u8]) -> io::Result<usize> {
     let pos = stream.stream_position()?;
     let size = stream.stable_stream_len()?;
+    if pos == size {
+        return Ok(0);
+    }
     stream.base_stream().read(if pos + buf.len() as u64 > size {
         &mut buf[..(size - pos) as usize]
     } else {
@@ -185,8 +195,10 @@ impl Read for ByteReadStream<'_> {
         let total = self.bytes.len();
         let pos = self.position as usize;
         if len + pos > total {
-            if pos >= total {
+            if pos > total {
                 return Err(io::Error::from(io::ErrorKind::UnexpectedEof));
+            } else if pos == total {
+                return Ok(0);
             }
             len = total - pos;
         }