eager evaluation was the first problem

examples/read.rs

@@ -1,18 +1,8 @@
 fn main() -> Result<(), un_pak::Error> {
-    let path = std::env::args().nth(1).unwrap_or_default();
-    for version in un_pak::Version::iter() {
-        print!("{version} - ");
-        match un_pak::Pak::new(
-            version,
-            std::io::BufReader::new(std::fs::OpenOptions::new().read(true).open(&path)?),
-        ) {
-            Ok(pak) => {
-                print!("{:#?}", pak);
-                println!("parsed successfully!");
-            }
-            Err(e) => println!("{e}"),
-        }
-    }
-    std::thread::sleep_ms(10000);
+    let pak = un_pak::Pak::new(
+        un_pak::Version::CompressionEncryption,
+        std::io::Cursor::new(include_bytes!("rando_p.pak")),
+    )?;
+    print!("{:#?}", pak);
     Ok(())
 }

src/entry.rs

@@ -17,7 +17,7 @@ pub struct Entry {
 impl Entry {
     pub fn new<R: std::io::Read>(
         reader: &mut R,
-        version: &super::Version,
+        version: super::Version,
     ) -> Result<Self, super::Error> {
         let name = reader.read_string()?;
         let offset = reader.read_u64::<LE>()?;
@@ -35,9 +35,9 @@ impl Entry {
             compressed,
             uncompressed,
             compression_method,
-            timestamp: (version == &Version::Initial).then_some(reader.read_u64::<LE>()?),
+            timestamp: (version == Version::Initial).then_some(reader.read_u64::<LE>()?),
             hash: reader.read_guid()?,
-            compression_blocks: (version >= &Version::CompressionEncryption
+            compression_blocks: (version >= Version::CompressionEncryption
                 && compression_method != Compression::None)
                 .then_some(reader.read_array(Block::new)?),
         })

src/error.rs

@@ -1,11 +1,9 @@
 #[derive(thiserror::Error, Debug)]
 pub enum Error {
-    #[error("illegal file magic of {0}")]
+    #[error("found magic of {0:#x} instead of {:#x}", super::MAGIC)]
     WrongMagic(u32),
     #[error("used version {0} but pak is version {1}")]
     WrongVersion(super::Version, super::Version),
-    #[error("couldn't convert {0} to boolean")]
-    BoolConv(u8),
     #[error("io error: {0}")]
     IoError(#[from] std::io::Error),
     #[error("enum conversion: {0}")]
@@ -14,6 +12,8 @@ pub enum Error {
     Utf8Conv(#[from] std::string::FromUtf8Error),
     #[error("utf16 conversion: {0}")]
     Utf16Conv(#[from] std::string::FromUtf16Error),
+    #[error("got {0}, which is not a boolean")]
+    BoolConv(u8),
     #[error("{0}")]
     Other(String),
 }

src/ext.rs

@@ -39,7 +39,6 @@ impl<R: std::io::Read> ReadExt for R {
 
     fn read_string(&mut self) -> Result<String, crate::Error> {
         Ok(match self.read_i32::<LE>()? {
-            size if size.is_positive() => String::from_utf8(self.read_len(size as usize)?)?,
             size if size.is_negative() => {
                 let mut buf = Vec::with_capacity(-size as usize);
                 for _ in 0..buf.capacity() {
@@ -47,12 +46,12 @@ impl<R: std::io::Read> ReadExt for R {
                 }
                 String::from_utf16(&buf)?
             }
-            _ => String::new(),
+            size => String::from_utf8(self.read_len(size as usize)?)?,
         })
     }
 
     fn read_len(&mut self, len: usize) -> Result<Vec<u8>, super::Error> {
-        let mut buf = Vec::with_capacity(len);
+        let mut buf = vec![0; len];
         self.read_exact(&mut buf)?;
         Ok(buf)
     }

src/footer.rs

@@ -18,44 +18,55 @@ pub struct Footer {
 }
 
 impl Footer {
-    pub fn new<R: std::io::Read>(reader: &mut R, version: &Version) -> Result<Self, super::Error> {
-        let footer = Footer {
-            encryption_uuid: (version >= &Version::EncryptionKeyGuid)
-                .then_some(reader.read_u128::<LE>()?),
-            encrypted: (version >= &Version::CompressionEncryption).then_some(reader.read_bool()?),
+    pub fn new<R: std::io::Read>(reader: &mut R, version: Version) -> Result<Self, super::Error> {
+        let footer = Self {
+            encryption_uuid: match version >= Version::EncryptionKeyGuid {
+                true => Some(reader.read_u128::<LE>()?),
+                false => None,
+            },
+            encrypted: match version >= Version::IndexEncryption {
+                true => Some(reader.read_bool()?),
+                false => None,
+            },
             magic: reader.read_u32::<LE>()?,
-            version: Version::from_repr(reader.read_u32::<LE>()?).unwrap_or_default(),
+            version: Version::from_repr(reader.read_u32::<LE>()?).unwrap_or(version),
             offset: reader.read_u64::<LE>()?,
             size: reader.read_u64::<LE>()?,
             hash: reader.read_guid()?,
-            frozen: (version == &Version::FrozenIndex).then_some(reader.read_bool()?),
-            compression: (version >= &Version::FNameBasedCompression).then_some({
-                let mut compression =
-                    Vec::with_capacity(match version == &Version::FNameBasedCompression {
-                        true => 4,
-                        false => 5,
-                    });
-                for _ in 0..compression.capacity() {
-                    compression.push(
-                        Compression::from_str(
-                            &reader
-                                .read_len(32)?
-                                .iter()
-                                // filter out whitespace and convert to char
-                                .filter_map(|&ch| (ch != 0).then_some(ch as char))
-                                .collect::<String>(),
+            frozen: match version == Version::FrozenIndex {
+                true => Some(reader.read_bool()?),
+                false => None,
+            },
+            compression: match version >= Version::FNameBasedCompression {
+                true => {
+                    let mut compression =
+                        Vec::with_capacity(match version == Version::FNameBasedCompression {
+                            true => 4,
+                            false => 5,
+                        });
+                    for _ in 0..compression.capacity() {
+                        compression.push(
+                            Compression::from_str(
+                                &reader
+                                    .read_len(32)?
+                                    .iter()
+                                    // filter out whitespace and convert to char
+                                    .filter_map(|&ch| (ch != 0).then_some(ch as char))
+                                    .collect::<String>(),
+                            )
+                            .unwrap_or_default(),
                         )
-                        .unwrap_or_default(),
-                    )
+                    }
+                    Some(compression)
                 }
-                compression
-            }),
+                false => None,
+            },
         };
         if super::MAGIC != footer.magic {
             return Err(super::Error::WrongMagic(footer.magic));
         }
-        if version != &footer.version {
-            return Err(super::Error::WrongVersion(*version, footer.version));
+        if version != footer.version {
+            return Err(super::Error::WrongVersion(version, footer.version));
         }
         Ok(footer)
     }

src/index.rs

@@ -7,8 +7,8 @@ pub enum Index {
 }
 
 impl Index {
-    pub fn new<R: std::io::Read>(reader: &mut R, version: &Version) -> Result<Self, super::Error> {
-        Ok(match version < &Version::PathHashIndex {
+    pub fn new<R: std::io::Read>(reader: &mut R, version: Version) -> Result<Self, super::Error> {
+        Ok(match version < Version::PathHashIndex {
             true => Index::WithoutPathHash(IndexV1::new(reader, version)?),
             false => Index::WithPathHash,
         })
@@ -24,7 +24,7 @@ pub struct IndexV1 {
 impl IndexV1 {
     pub fn new<R: std::io::Read>(
         reader: &mut R,
-        version: &super::Version,
+        version: super::Version,
     ) -> Result<Self, super::Error> {
         Ok(Self {
             mount_point: reader.read_string()?,

src/lib.rs

@@ -12,19 +12,10 @@ pub const MAGIC: u32 = 0x5A6F12E1;
 
 #[repr(u32)]
 #[derive(
-    Default,
-    Clone,
-    Copy,
-    PartialEq,
-    Eq,
-    PartialOrd,
-    Debug,
-    strum::Display,
-    strum::FromRepr,
-    strum::EnumIter,
+    Clone, Copy, PartialEq, Eq, PartialOrd, Debug, strum::Display, strum::FromRepr, strum::EnumIter,
 )]
 pub enum Version {
-    Unknown,               // unknown (mostly just for padding :p)
+    Unknown,               // unknown (mostly just for padding)
     Initial,               // initial specification
     NoTimestamps,          // timestamps removed
     CompressionEncryption, // compression and encryption support
@@ -34,8 +25,7 @@ pub enum Version {
     EncryptionKeyGuid,     // include key GUID
     FNameBasedCompression, // compression names included
     FrozenIndex,           // frozen index byte included
-    #[default]
-    PathHashIndex, // more compression methods
+    PathHashIndex,         // more compression methods
 }
 
 // strum shouldn't need to be installed by users

src/pak.rs

@@ -15,9 +15,9 @@ impl Pak {
         mut reader: R,
     ) -> Result<Self, super::Error> {
         reader.seek(io::SeekFrom::End(-footer_size(&version)))?;
-        let footer = super::Footer::new(&mut reader, &version)?;
+        let footer = super::Footer::new(&mut reader, version)?;
         reader.seek(io::SeekFrom::Start(footer.offset))?;
-        let index = super::Index::new(&mut reader, &version)?;
+        let index = super::Index::new(&mut reader, version)?;
         Ok(Self {
             version,
             footer,