Break code into modules

src/bin/dump.rs

@@ -4,8 +4,9 @@ use std::env::args;
 use std::fs::File;
 use std::io::Read;
 use std::path::Path;
-use lab_ebml::{Schema, Webm};
-use lab_ebml::WebmElement::*;
+use lab_ebml::Schema;
+use lab_ebml::webm::Webm;
+use lab_ebml::webm::WebmElement::*;
 
 pub fn main() {
     let mut args = args();

src/ebml.rs

@@ -0,0 +1,135 @@
+pub const EBML_HEAD_ID: u64 = 0x0A45DFA3;
+pub const VOID_ID: u64 = 0x6C;
+
+#[derive(Debug, PartialEq)]
+pub enum Error {
+    CorruptVarint,
+    UnknownElementId,
+    UnknownElementLength,
+    CorruptPayload,
+}
+
+#[derive(Debug, PartialEq)]
+pub enum Varint {
+    /// a numeric value
+    Value(u64),
+    /// the reserved "unknown" value
+    Unknown
+}
+
+/// Try to parse an EBML varint at the start of the given slice.
+/// Returns an Err() if the format is corrupt.
+/// Returns Ok(None) if more bytes are needed to get a result.
+/// Returns Ok(Some((varint, size))) to return a varint value and
+/// the size of the parsed varint.
+pub fn decode_varint(bytes: &[u8]) -> Result<Option<(Varint, usize)>, Error> {
+    let mut value: u64 = 0;
+    let mut value_length = 1;
+    let mut mask: u8 = 0x80;
+    let mut unknown_marker: u64 = !0;
+
+    if bytes.len() == 0 {
+        return Ok(None)
+    }
+
+    // get length marker bit from first byte & parse first byte
+    while mask > 0 {
+        if (mask & bytes[0]) != 0 {
+            value = (bytes[0] & !mask) as u64;
+            unknown_marker = (mask - 1) as u64;
+            break
+        }
+        value_length += 1;
+        mask = mask >> 1;
+    }
+
+    if mask == 0 {
+        return Err(Error::CorruptVarint)
+    }
+
+    // check we have enough data to parse
+    if value_length > bytes.len() {
+        return Ok(None)
+    }
+
+    // decode remaining bytes
+    for i in 1..value_length {
+        value = (value << 8) + (bytes[i] as u64);
+        unknown_marker = (unknown_marker << 8) + 0xFF;
+    }
+
+    // determine result
+    if value == unknown_marker {
+        Ok(Some((Varint::Unknown, value_length)))
+    } else {
+        Ok(Some((Varint::Value(value), value_length)))
+    }
+}
+
+/// Try to parse an EBML element header at the start of the given slice.
+/// Returns an Err() if the format is corrupt.
+/// Returns Ok(None) if more bytes are needed to get a result.
+/// Returns Ok(Some((id, varint, size))) to return the element id,
+/// the size of the payload, and the size of the parsed header.
+pub fn decode_tag(bytes: &[u8]) -> Result<Option<(u64, Varint, usize)>, Error> {
+    // parse element ID
+    match decode_varint(bytes) {
+        Ok(None) => Ok(None),
+        Err(err) => Err(err),
+        Ok(Some((Varint::Unknown, _))) => Err(Error::UnknownElementId),
+        Ok(Some((Varint::Value(element_id), id_size))) => {
+            // parse payload size
+            match decode_varint(&bytes[id_size..]) {
+                Ok(None) => Ok(None),
+                Err(err) => Err(err),
+                Ok(Some((element_length, length_size))) =>
+                    Ok(Some((
+                        element_id,
+                        element_length,
+                        id_size + length_size
+                    )))
+            }
+        }
+    }
+}
+
+#[derive(Debug, PartialEq)]
+pub struct Ebml<S, T>(pub S, pub T);
+
+pub trait Schema<'a> {
+    type Element: 'a;
+
+    fn should_unwrap(&self, element_id: u64) -> bool;
+    fn decode<'b: 'a>(&self, element_id: u64, bytes: &'b[u8]) -> Result<Self::Element, Error>;
+
+    fn decode_element<'b: 'a>(&self, bytes: &'b[u8]) -> Result<Option<(Self::Element, usize)>, Error> {
+        match decode_tag(bytes) {
+            Ok(None) => Ok(None),
+            Err(err) => Err(err),
+            Ok(Some((element_id, payload_size_tag, tag_size))) => {
+                let should_unwrap = self.should_unwrap(element_id);
+
+                let payload_size = match (should_unwrap, payload_size_tag) {
+                    (true, _) => 0,
+                    (false, Varint::Unknown) => return Err(Error::UnknownElementLength),
+                    (false, Varint::Value(size)) => size as usize
+                };
+
+                let element_size = tag_size + payload_size;
+                if element_size > bytes.len() {
+                    // need to read more still
+                    return Ok(None);
+                }
+
+                match self.decode(element_id, &bytes[tag_size..element_size]) {
+                    Ok(element) => Ok(Some((element, element_size))),
+                    Err(error) => Err(error)
+                }
+            }
+        }
+    }
+
+    fn parse<T>(self, source: T) -> Ebml<Self, T> where Self: Sized {
+        Ebml(self, source)
+    }
+}

src/iterator.rs

@@ -0,0 +1,36 @@
+use ebml::*;
+
+pub struct EbmlIterator<'b, T: Schema<'b>> {
+    schema: T,
+    slice: &'b[u8],
+    position: usize,
+}
+
+impl<'b, S: Schema<'b>> IntoIterator for Ebml<S, &'b[u8]> {
+    type Item = S::Element;
+    type IntoIter = EbmlIterator<'b, S>;
+
+    fn into_iter(self) -> EbmlIterator<'b, S>
+    {
+        EbmlIterator {
+            schema: self.0,
+            slice: self.1,
+            position: 0
+        }
+    }
+}
+
+impl<'b, T: Schema<'b>> Iterator for EbmlIterator<'b, T> {
+    type Item = T::Element;
+
+    fn next(&mut self) -> Option<T::Element> {
+        match self.schema.decode_element(&self.slice[self.position..]) {
+            Err(_) => None,
+            Ok(None) => None,
+            Ok(Some((element, element_size))) => {
+                self.position += element_size;
+                Some(element)
+            }
+        }
+    }
+}

src/lib.rs

@@ -1,224 +1,11 @@
 
 extern crate futures;
 
-#[derive(Debug, PartialEq)]
-pub enum Error {
-    CorruptVarint,
-    UnknownElementId,
-    UnknownElementLength,
-    CorruptPayload,
-}
+pub mod ebml;
+mod iterator;
+pub mod webm;
 
-#[derive(Debug, PartialEq)]
-pub enum Varint {
-    /// a numeric value
-    Value(u64),
-    /// the reserved "unknown" value
-    Unknown
-}
-
-/// Try to parse an EBML varint at the start of the given slice.
-/// Returns an Err() if the format is corrupt.
-/// Returns Ok(None) if more bytes are needed to get a result.
-/// Returns Ok(Some((varint, size))) to return a varint value and
-/// the size of the parsed varint.
-pub fn decode_varint(bytes: &[u8]) -> Result<Option<(Varint, usize)>, Error> {
-    let mut value: u64 = 0;
-    let mut value_length = 1;
-    let mut mask: u8 = 0x80;
-    let mut unknown_marker: u64 = !0;
-
-    if bytes.len() == 0 {
-        return Ok(None)
-    }
-
-    // get length marker bit from first byte & parse first byte
-    while mask > 0 {
-        if (mask & bytes[0]) != 0 {
-            value = (bytes[0] & !mask) as u64;
-            unknown_marker = (mask - 1) as u64;
-            break
-        }
-        value_length += 1;
-        mask = mask >> 1;
-    }
-
-    if mask == 0 {
-        return Err(Error::CorruptVarint)
-    }
-
-    // check we have enough data to parse
-    if value_length > bytes.len() {
-        return Ok(None)
-    }
-
-    // decode remaining bytes
-    for i in 1..value_length {
-        value = (value << 8) + (bytes[i] as u64);
-        unknown_marker = (unknown_marker << 8) + 0xFF;
-    }
-
-    // determine result
-    if value == unknown_marker {
-        Ok(Some((Varint::Unknown, value_length)))
-    } else {
-        Ok(Some((Varint::Value(value), value_length)))
-    }
-}
-
-/// Try to parse an EBML element header at the start of the given slice.
-/// Returns an Err() if the format is corrupt.
-/// Returns Ok(None) if more bytes are needed to get a result.
-/// Returns Ok(Some((id, varint, size))) to return the element id,
-/// the size of the payload, and the size of the parsed header.
-pub fn decode_tag(bytes: &[u8]) -> Result<Option<(u64, Varint, usize)>, Error> {
-    // parse element ID
-    match decode_varint(bytes) {
-        Ok(None) => Ok(None),
-        Err(err) => Err(err),
-        Ok(Some((Varint::Unknown, _))) => Err(Error::UnknownElementId),
-        Ok(Some((Varint::Value(element_id), id_size))) => {
-            // parse payload size
-            match decode_varint(&bytes[id_size..]) {
-                Ok(None) => Ok(None),
-                Err(err) => Err(err),
-                Ok(Some((element_length, length_size))) =>
-                    Ok(Some((
-                        element_id,
-                        element_length,
-                        id_size + length_size
-                    )))
-            }
-        }
-    }
-}
-
-pub trait Schema<'a> {
-    type Element: 'a;
-
-    fn should_unwrap(&self, element_id: u64) -> bool;
-    fn decode<'b: 'a>(&self, element_id: u64, bytes: &'b[u8]) -> Result<Self::Element, Error>;
-
-    fn decode_element<'b: 'a>(&self, bytes: &'b[u8]) -> Result<Option<(Self::Element, usize)>, Error> {
-        match decode_tag(bytes) {
-            Ok(None) => Ok(None),
-            Err(err) => Err(err),
-            Ok(Some((element_id, payload_size_tag, tag_size))) => {
-                let should_unwrap = self.should_unwrap(element_id);
-
-                let payload_size = match (should_unwrap, payload_size_tag) {
-                    (true, _) => 0,
-                    (false, Varint::Unknown) => return Err(Error::UnknownElementLength),
-                    (false, Varint::Value(size)) => size as usize
-                };
-
-                let element_size = tag_size + payload_size;
-                if element_size > bytes.len() {
-                    // need to read more still
-                    return Ok(None);
-                }
-
-                match self.decode(element_id, &bytes[tag_size..element_size]) {
-                    Ok(element) => Ok(Some((element, element_size))),
-                    Err(error) => Err(error)
-                }
-            }
-        }
-    }
-
-    fn parse<T>(self, source: T) -> Ebml<Self, T> where Self: Sized {
-        Ebml(self, source)
-    }
-
-}
-
-pub const EBML_HEAD_ID: u64 = 0x0A45DFA3;
-pub const VOID_ID: u64 = 0x6C;
-
-#[derive(Debug, PartialEq)]
-pub struct Ebml<S, T>(S, T);
-
-impl<'b, S: Schema<'b>> IntoIterator for Ebml<S, &'b[u8]> {
-    type Item = S::Element;
-    type IntoIter = EbmlIterator<'b, S>;
-
-    fn into_iter(self) -> EbmlIterator<'b, S>
-    {
-        EbmlIterator {
-            schema: self.0,
-            slice: self.1,
-            position: 0
-        }
-    }
-}
-
-const SEGMENT_ID: u64 = 0x08538067;
-const SEEK_HEAD_ID: u64 = 0x014D9B74;
-const SEGMENT_INFO_ID: u64 = 0x0549A966;
-const CUES_ID: u64 = 0x0C53BB6B;
-const TRACKS_ID: u64 = 0x0654AE6B;
-const CLUSTER_ID: u64 = 0x0F43B675;
-pub struct Webm;
-
-#[derive(Debug, PartialEq)]
-pub enum WebmElement<'b> {
-    EbmlHead,
-    Void,
-    Segment,
-    SeekHead,
-    Info,
-    Cues,
-    Tracks(&'b[u8]),
-    Cluster(&'b[u8]),
-    Unknown(u64)
-}
-
-impl<'a> Schema<'a> for Webm {
-    type Element = WebmElement<'a>;
-
-    fn should_unwrap(&self, element_id: u64) -> bool {
-        match element_id {
-            // Segment
-            SEGMENT_ID => true,
-            _ => false
-        }
-    }
-
-    fn decode<'b: 'a>(&self, element_id: u64, bytes: &'b[u8]) -> Result<WebmElement<'b>, Error> {
-        match element_id {
-            EBML_HEAD_ID => Ok(WebmElement::EbmlHead),
-            VOID_ID => Ok(WebmElement::Void),
-            SEGMENT_ID => Ok(WebmElement::Segment),
-            SEEK_HEAD_ID => Ok(WebmElement::SeekHead),
-            SEGMENT_INFO_ID => Ok(WebmElement::Info),
-            CUES_ID => Ok(WebmElement::Cues),
-            TRACKS_ID => Ok(WebmElement::Tracks(bytes)),
-            CLUSTER_ID => Ok(WebmElement::Cluster(bytes)),
-            _ => Ok(WebmElement::Unknown(element_id))
-        }
-    }
-}
-
-pub struct EbmlIterator<'b, T: Schema<'b>> {
-    schema: T,
-    slice: &'b[u8],
-    position: usize,
-}
-
-impl<'b, T: Schema<'b>> Iterator for EbmlIterator<'b, T> {
-    type Item = T::Element;
-
-    fn next(&mut self) -> Option<T::Element> {
-        match self.schema.decode_element(&self.slice[self.position..]) {
-            Err(_) => None,
-            Ok(None) => None,
-            Ok(Some((element, element_size))) => {
-                self.position += element_size;
-                Some(element)
-            }
-        }
-    }
-}
+pub use ebml::{Error, Schema};
 
 #[cfg(test)]
 mod tests {

src/webm.rs

@@ -0,0 +1,48 @@
+use ebml::*;
+
+const SEGMENT_ID: u64 = 0x08538067;
+const SEEK_HEAD_ID: u64 = 0x014D9B74;
+const SEGMENT_INFO_ID: u64 = 0x0549A966;
+const CUES_ID: u64 = 0x0C53BB6B;
+const TRACKS_ID: u64 = 0x0654AE6B;
+const CLUSTER_ID: u64 = 0x0F43B675;
+pub struct Webm;
+
+#[derive(Debug, PartialEq)]
+pub enum WebmElement<'b> {
+    EbmlHead,
+    Void,
+    Segment,
+    SeekHead,
+    Info,
+    Cues,
+    Tracks(&'b[u8]),
+    Cluster(&'b[u8]),
+    Unknown(u64)
+}
+
+impl<'a> Schema<'a> for Webm {
+    type Element = WebmElement<'a>;
+
+    fn should_unwrap(&self, element_id: u64) -> bool {
+        match element_id {
+            // Segment
+            SEGMENT_ID => true,
+            _ => false
+        }
+    }
+
+    fn decode<'b: 'a>(&self, element_id: u64, bytes: &'b[u8]) -> Result<WebmElement<'b>, Error> {
+        match element_id {
+            EBML_HEAD_ID => Ok(WebmElement::EbmlHead),
+            VOID_ID => Ok(WebmElement::Void),
+            SEGMENT_ID => Ok(WebmElement::Segment),
+            SEEK_HEAD_ID => Ok(WebmElement::SeekHead),
+            SEGMENT_INFO_ID => Ok(WebmElement::Info),
+            CUES_ID => Ok(WebmElement::Cues),
+            TRACKS_ID => Ok(WebmElement::Tracks(bytes)),
+            CLUSTER_ID => Ok(WebmElement::Cluster(bytes)),
+            _ => Ok(WebmElement::Unknown(element_id))
+        }
+    }
+}