Merge pull request #2 from gushromp/master

Split Stream and Struct traits into modules

.gitignore

@@ -5,3 +5,10 @@
 # Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
 # More information here http://doc.crates.io/guide.html#cargotoml-vs-cargolock
 Cargo.lock
+
+# These are backup files generated by rustfmt
+**/*.rs.bk
+
+# Various IDE metadata
+.vscode/*
+.idea/*

src/kaitai_stream.rs

@@ -0,0 +1,308 @@
+use std::io::{Cursor, Seek, SeekFrom, Read, Result};
+use flate2::read::ZlibDecoder;
+
+use byteorder::{BigEndian, ByteOrder, LittleEndian};
+use encoding::DecoderTrap;
+use encoding::label::encoding_from_whatwg_label;
+
+macro_rules! read_endian {
+    ($this:ident, $size:expr, $end:ident, $method:ident) => {{
+        let mut buf = [0; $size];
+        try!($this.read_exact(&mut buf));
+        Ok($end::$method(&buf))
+    }}
+}
+
+pub trait KaitaiStream: Read + Seek {
+    // ------------------ //
+    // Stream positioning //
+    // ------------------ //
+
+    fn is_eof(&mut self) -> Result<bool> {
+        // TODO: I'm positive there's a better way to do this!
+        // See also the `size` implementation
+        let pos = self.pos()?;
+        let size = Seek::seek(self, SeekFrom::End(0))?;
+        Seek::seek(self, SeekFrom::Start(pos))?;
+        return Ok(pos >= size);
+    }
+
+    fn seek(&mut self, position: u64) -> Result<()> {
+        match Seek::seek(self, SeekFrom::Start(position)) {
+            Ok(_) => Ok(()),
+            Err(e) => Err(e),
+        }
+    }
+
+    fn pos(&mut self) -> Result<u64> {
+        match Seek::seek(self, SeekFrom::Current(0)) {
+            Ok(i) => Ok(i as u64),
+            Err(e) => Err(e),
+        }
+    }
+
+    fn size(&mut self) -> Result<u64> {
+        // TODO: I'm positive there's a better way to do this!
+        let pos = self.pos()?;
+        let size = Seek::seek(self, SeekFrom::End(0))?;
+        Seek::seek(self, SeekFrom::Start(pos))?;
+        return Ok(size);
+    }
+
+    // ---------------------- //
+    // Integer types - signed //
+    // ---------------------- //
+
+    fn read_s1(&mut self) -> Result<i8> {
+        let mut buf = [0; 1];
+        self.read_exact(&mut buf)?;
+        Ok(buf[0] as i8)
+    }
+
+    // Big endian
+
+    fn read_s2be(&mut self) -> Result<i16> {
+        read_endian!(self, 2, BigEndian, read_i16)
+    }
+
+    fn read_s4be(&mut self) -> Result<i32> {
+        read_endian!(self, 4, BigEndian, read_i32)
+    }
+
+    fn read_s8be(&mut self) -> Result<i64> {
+        read_endian!(self, 8, BigEndian, read_i64)
+    }
+
+    // Little endian
+
+    fn read_s2le(&mut self) -> Result<i16> {
+        read_endian!(self, 2, LittleEndian, read_i16)
+    }
+
+    fn read_s4le(&mut self) -> Result<i32> {
+        read_endian!(self, 4, LittleEndian, read_i32)
+    }
+
+    fn read_s8le(&mut self) -> Result<i64> {
+        read_endian!(self, 8, LittleEndian, read_i64)
+    }
+
+    // ------------------------ //
+    // Integer types - unsigned //
+    // ------------------------ //
+
+    fn read_u1(&mut self) -> Result<u8> {
+        let mut buf = [0; 1];
+        self.read_exact(&mut buf)?;
+        Ok(buf[0])
+    }
+
+    // Big endian
+
+    fn read_u2be(&mut self) -> Result<u16> {
+        read_endian!(self, 2, BigEndian, read_u16)
+    }
+
+    fn read_u4be(&mut self) -> Result<u32> {
+        read_endian!(self, 4, BigEndian, read_u32)
+    }
+
+    fn read_u8be(&mut self) -> Result<u64> {
+        read_endian!(self, 8, BigEndian, read_u64)
+    }
+
+    // Little endian
+
+    fn read_u2le(&mut self) -> Result<u16> {
+        read_endian!(self, 2, LittleEndian, read_u16)
+    }
+
+    fn read_u4le(&mut self) -> Result<u32> {
+        read_endian!(self, 4, LittleEndian, read_u32)
+    }
+
+    fn read_u8le(&mut self) -> Result<u64> {
+        read_endian!(self, 8, LittleEndian, read_u64)
+    }
+
+    // -------------------- //
+    // Floating point types //
+    // -------------------- //
+
+    // Big endian
+
+    fn read_f4be(&mut self) -> Result<f32> {
+        read_endian!(self, 4, BigEndian, read_f32)
+    }
+
+    fn read_f8be(&mut self) -> Result<f64> {
+        read_endian!(self, 8, BigEndian, read_f64)
+    }
+
+    // Little endian
+
+    fn read_f4le(&mut self) -> Result<f32> {
+        read_endian!(self, 4, LittleEndian, read_f32)
+    }
+
+    fn read_f8le(&mut self) -> Result<f64> {
+        read_endian!(self, 8, LittleEndian, read_f64)
+    }
+
+    // ----------- //
+    // Byte arrays //
+    // ----------- //
+
+    fn read_bytes(&mut self, count: usize) -> Result<Vec<u8>> {
+        let mut buffer = vec![0; count];
+        match self.read_exact(&mut buffer[..]) {
+            Ok(_) => Ok(buffer),
+            Err(e) => Err(e),
+        }
+    }
+
+    fn read_bytes_full(&mut self) -> Result<Vec<u8>> {
+        let mut buffer = vec![0; 0];
+        match self.read_to_end(&mut buffer) {
+            Ok(_) => Ok(buffer),
+            Err(e) => Err(e),
+        }
+    }
+
+    fn ensure_fixed_contents(&mut self, count: usize, expected: Vec<u8>) -> Result<Vec<u8>> {
+        let mut buffer = vec![0; count];
+        match self.read_exact(&mut buffer[..]) {
+            Ok(_) => {
+                assert_eq!(buffer, expected);
+                Ok(buffer)
+            }
+            Err(e) => Err(e),
+        }
+    }
+
+    // ------- //
+    // Strings //
+    // ------- //
+
+    fn read_str_eos(&mut self, encoding: &str) -> Result<String> {
+        match encoding_from_whatwg_label(encoding) {
+            Some(enc) => {
+                let buffer = self.read_bytes_full()?;
+                match enc.decode(&buffer, DecoderTrap::Strict) {
+                    Ok(s) => Ok(s),
+                    Err(e) => panic!("Error decoding string: {}", e),
+                }
+            }
+            None => panic!("Unknown encoding: {}", encoding),
+        }
+    }
+
+    fn read_str_byte_limit(&mut self, length: usize, encoding: &str) -> Result<String> {
+        match encoding_from_whatwg_label(encoding) {
+            Some(enc) => {
+                let buffer = self.read_bytes(length)?;
+                match enc.decode(&buffer, DecoderTrap::Strict) {
+                    Ok(s) => Ok(s),
+                    Err(e) => panic!("Error decoding string: {}", e),
+                }
+            }
+            None => panic!("Unknown encoding: {}", encoding),
+        }
+    }
+
+    fn read_strz(&mut self,
+                 encoding: &str,
+                 terminator: u8,
+                 include_terminator: bool,
+                 consume_terminator: bool,
+                 eos_error: bool)
+                 -> Result<String> {
+        let enc = match encoding_from_whatwg_label(encoding) {
+            Some(enc) => enc,
+            None => panic!("Unknown encoding: {}", encoding),
+        };
+        let mut buffer = vec![];
+        let mut c = vec![0; 1];
+        loop {
+            match self.read_exact(&mut c[..]) {
+                Ok(_) => {}
+                Err(e) => {
+                    if eos_error {
+                        return Err(e);
+                    }
+                    break;
+                }
+            };
+            if c[0] == terminator {
+                if include_terminator {
+                    buffer.push(c[0])
+                }
+                if !consume_terminator {
+                    let pos = self.pos()?;
+                    Seek::seek(self, SeekFrom::Start((pos - 1) as u64))?;
+                }
+                break;
+            }
+            buffer.push(c[0])
+        }
+        match enc.decode(&buffer, DecoderTrap::Strict) {
+            Ok(s) => Ok(s),
+            Err(e) => panic!("Error decoding string: {}", e),
+        }
+    }
+
+    // --------------------- //
+    // Byte array processing //
+    // --------------------- //
+
+    fn process_xor_one(&mut self, value: Vec<u8>, key: u8) -> Vec<u8> {
+        let mut result = vec![0; value.len()];
+        for i in 0..value.len() {
+            result[i] = (value[i] ^ key) as u8;
+        }
+        return result;
+    }
+
+    fn process_xor_many(&mut self, value: Vec<u8>, key: Vec<u8>) -> Vec<u8> {
+        let mut result = vec![0; value.len()];
+        let mut j = 0;
+        for i in 0..value.len() {
+            result[i] = (value[i] ^ key[j]) as u8;
+            j = (j + 1) % key.len();
+        }
+        return result;
+    }
+
+    fn process_rotate_left(&mut self, data: Vec<u8>, amount: i32, group_size: i32) -> Vec<u8> {
+        if amount < -7 || amount > 7 {
+            panic!("Rotation of more than 7 cannot be performed.");
+        }
+
+        let mut rot_amount = amount;
+        if rot_amount < 0 {
+            rot_amount += 8;
+        }
+
+        let mut result = vec![0; data.len()];
+        match group_size {
+            1 => {
+                for i in 0..data.len() {
+                    result[i] = data[i].rotate_left(rot_amount as u32);
+                }
+            }
+            _ => panic!("Unable to rotate a group of {} bytes yet", group_size),
+        }
+        return result;
+    }
+
+    fn process_zlib(&mut self, data: Vec<u8>) -> Result<Vec<u8>> {
+        let mut decoder = ZlibDecoder::new(Cursor::new(data));
+        let mut result = Vec::new();
+        match decoder.read_to_end(&mut result) {
+            Ok(_) => Ok(result),
+            Err(e) => Err(e),
+        }
+    }
+}
+
+impl<T: Read + Seek> KaitaiStream for T {}

src/kaitai_struct.rs

@@ -0,0 +1,9 @@
+use std;
+use kaitai_stream::KaitaiStream;
+
+pub trait KaitaiStruct {
+    fn empty() -> Self where Self : Sized;
+    fn from_file(path: &str) -> std::result::Result<Self, std::io::Error> where Self : Sized;
+    fn new<S: KaitaiStream>(stream: &mut S, parent: &Option<Box<KaitaiStruct>>, root: &Option<Box<KaitaiStruct>>) -> Self where Self : Sized;
+    fn read<S: KaitaiStream>(&mut self, stream: &mut S, parent: &Option<Box<KaitaiStruct>>, root: &Option<Box<KaitaiStruct>>) where Self : Sized;
+}