From 4b1541b630b6d75cb579c82eae0cf275aea0cc81 Mon Sep 17 00:00:00 2001
From: Matt Bilker <me@mbilker.us>
Date: Sat, 16 Jun 2018 02:17:09 -0400
Subject: [PATCH] error: generalize header read errors and add header interpret
 errors

---
 src/error.rs | 40 +++++++++++++++++-----------------------
 src/lib.rs   | 24 +++++++++++++++---------
 2 files changed, 32 insertions(+), 32 deletions(-)

diff --git a/src/error.rs b/src/error.rs
index ca2f382..8729a15 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -12,8 +12,20 @@ pub struct KbinError {
 
 #[derive(Debug, Fail)]
 pub enum KbinErrorKind {
-  #[fail(display = "Unable to read data")]
-  DataRead,
+  #[fail(display = "Unable to read {} byte from header", _0)]
+  HeaderRead(&'static str),
+
+  #[fail(display = "Unable to write {} header field", _0)]
+  HeaderWrite(&'static str),
+
+  #[fail(display = "Invalid byte value for {} header field", _0)]
+  HeaderValue(&'static str),
+
+  #[fail(display = "Unable to read {} bytes from data buffer", _0)]
+  DataRead(usize),
+
+  #[fail(display = "Unable to write a {} to data buffer", _0)]
+  DataWrite(&'static str),
 
   #[fail(display = "Unable to read data size")]
   DataReadSize,
@@ -30,21 +42,6 @@ pub enum KbinErrorKind {
   #[fail(display = "Unable to seek data buffer")]
   Seek,
 
-  #[fail(display = "Unable to read signature byte")]
-  SignatureRead,
-
-  #[fail(display = "Unable to read compression byte")]
-  CompressionRead,
-
-  #[fail(display = "Unknown compression value")]
-  UnknownCompression,
-
-  #[fail(display = "Unable to read encoding byte")]
-  EncodingRead,
-
-  #[fail(display = "Unable to read encoding negation byte")]
-  EncodingNegationRead,
-
   #[fail(display = "Unable to read len_node")]
   LenNodeRead,
 
@@ -78,18 +75,15 @@ pub enum KbinErrorKind {
   #[fail(display = "Unable to interpret string as UTF-8")]
   Utf8,
 
+  #[fail(display = "Unknown compression value")]
+  UnknownCompression,
+
   #[fail(display = "Unknown encoding")]
   UnknownEncoding,
 
   #[fail(display = "Unable to interpret string as alternate encoding")]
   Encoding,
 
-  #[fail(display = "Unable to write {} header field", _0)]
-  HeaderWrite(&'static str),
-
-  #[fail(display = "Unable to write a {}", _0)]
-  DataWrite(&'static str),
-
   #[fail(display = "Size Mismatch, type: {}, expected size: {}, actual size: {}", _0, _1, _2)]
   SizeMismatch(KbinType, usize, usize),
 
diff --git a/src/lib.rs b/src/lib.rs
index b6b9730..7650ecd 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -85,7 +85,7 @@ impl KbinXml {
     debug!("data_buf_read => index: {}, size: {}", data_buf.position(), size);
 
     let mut data = vec![0; size as usize];
-    data_buf.read_exact(&mut data).context(KbinErrorKind::DataRead)?;
+    data_buf.read_exact(&mut data).context(KbinErrorKind::DataRead(size as usize))?;
     trace!("data_buf_read => index: {}, size: {}, data: 0x{:02x?}", data_buf.position(), data.len(), data);
 
     self.data_buf_realign_reads(data_buf, None)?;
@@ -131,7 +131,7 @@ impl KbinXml {
 
   fn data_buf_get(&mut self, data_buf: &mut Cursor<&[u8]>, size: u32) -> Result<Vec<u8>> {
     let mut data = vec![0; size as usize];
-    data_buf.read_exact(&mut data).context(KbinErrorKind::DataRead)?;
+    data_buf.read_exact(&mut data).context(KbinErrorKind::DataRead(size as usize))?;
 
     Ok(data)
   }
@@ -283,19 +283,25 @@ impl KbinXml {
     // Data buffer starts later after reading `len_data`.
     let mut node_buf = Cursor::new(&input[..]);
 
-    let signature = node_buf.read_u8().context(KbinErrorKind::SignatureRead)?;
-    assert_eq!(signature, SIGNATURE);
+    let signature = node_buf.read_u8().context(KbinErrorKind::HeaderRead("signature"))?;
+    if signature != SIGNATURE {
+      return Err(KbinErrorKind::HeaderValue("signature").into());
+    }
 
     // TODO: support uncompressed
-    let compress_byte = node_buf.read_u8().context(KbinErrorKind::CompressionRead)?;
-    assert_eq!(compress_byte, SIG_COMPRESSED);
+    let compress_byte = node_buf.read_u8().context(KbinErrorKind::HeaderRead("compression"))?;
+    if compress_byte != SIG_COMPRESSED {
+      return Err(KbinErrorKind::HeaderValue("compression").into());
+    }
 
     let compressed = Compression::from_byte(compress_byte)?;
 
-    let encoding_byte = node_buf.read_u8().context(KbinErrorKind::EncodingRead)?;
-    let encoding_negation = node_buf.read_u8().context(KbinErrorKind::EncodingNegationRead)?;
+    let encoding_byte = node_buf.read_u8().context(KbinErrorKind::HeaderRead("encoding"))?;
+    let encoding_negation = node_buf.read_u8().context(KbinErrorKind::HeaderRead("encoding negation"))?;
     let encoding = EncodingType::from_byte(encoding_byte)?;
-    assert_eq!(encoding_negation, 0xFF ^ encoding_byte);
+    if encoding_negation != 0xFF ^ encoding_byte {
+      return Err(KbinErrorKind::HeaderValue("encoding negation").into());
+    }
 
     info!("signature: 0x{:x}", signature);
     info!("compression: 0x{:x} ({:?})", compress_byte, compressed);