EBML: Writing WIP

lofty/src/ebml/read/segment_cluster.rs

@@ -69,7 +69,7 @@ where
 					continue;
 				}
 
-				total_audio_data_size += (size.value() - u64::from(header_size));
+				total_audio_data_size += size.value() - u64::from(header_size);
 			},
 			ElementIdent::BlockGroup => read_block_group(
 				&mut children_reader.children(),
@@ -144,7 +144,7 @@ where
 			continue;
 		}
 
-		*total_audio_data_size += (size.value() - u64::from(header_size));
+		*total_audio_data_size += size.value() - u64::from(header_size);
 	}
 
 	Ok(())

lofty/src/ebml/read/segment_tags.rs

@@ -215,7 +215,7 @@ where
 
 	Ok(SimpleTag {
 		name: name.into(),
-		language,
+		language: language.unwrap_or_default(),
 		default,
 		value,
 	})

lofty/src/ebml/read/segment_tracks.rs

@@ -107,7 +107,7 @@ where
 					_ => unreachable!("Unhandled child element in TrackEntry: {:?}", ident),
 				}
 			},
-			ElementReaderYield::Master((id, size)) => match id {
+			ElementReaderYield::Master((id, _size)) => match id {
 				ElementIdent::Audio => {
 					read_audio_settings(&mut children_reader.children(), parse_options, &mut track)?
 				},

lofty/src/ebml/tag/mod.rs

@@ -16,7 +16,7 @@ pub use tag_name::*;
 pub use target::*;
 
 use crate::config::{global_options, WriteOptions};
-use crate::error::LoftyError;
+use crate::error::{LoftyError, Result};
 use crate::io::{FileLike, Length, Truncate};
 use crate::picture::Picture;
 use crate::tag::companion_tag::CompanionTag;
@@ -25,7 +25,6 @@ use crate::tag::{Accessor, MergeTag, SplitTag, TagExt, TagType};
 use std::borrow::Cow;
 use std::io::Write;
 use std::ops::Deref;
-use std::path::Path;
 
 use lofty_attr::tag;
 
@@ -405,3 +404,40 @@ impl From<crate::tag::Tag> for MatroskaTag {
 		SplitTagRemainder::default().merge_tag(input)
 	}
 }
+
+pub(crate) struct MatroskaTagRef<'a, I, S>
+where
+	I: Iterator<Item = TagRef<'a, S>>,
+	S: Iterator<Item = Cow<'a, SimpleTag<'a>>> + 'a,
+{
+	tags: I,
+}
+
+impl<'a, I, S> From<&'a crate::tag::Tag> for MatroskaTagRef<'a, I, S>
+where
+	I: Iterator<Item = TagRef<'a, S>>,
+	S: Iterator<Item = Cow<'a, SimpleTag<'a>>>,
+{
+	fn from(_tag: &'a crate::tag::Tag) -> Self {
+		todo!()
+	}
+}
+
+impl<'a, I, S> MatroskaTagRef<'a, I, S>
+where
+	I: Iterator<Item = TagRef<'a, S>>,
+	S: Iterator<Item = Cow<'a, SimpleTag<'a>>>,
+{
+	pub(crate) fn write_to<F>(&mut self, _file: &mut F, _write_options: WriteOptions) -> Result<()>
+	where
+		F: FileLike,
+		LoftyError: From<<F as Truncate>::Error>,
+		LoftyError: From<<F as Length>::Error>,
+	{
+		todo!()
+	}
+
+	fn dump_to<W: Write>(&self, _writer: &mut W, _write_options: WriteOptions) -> Result<()> {
+		todo!()
+	}
+}

lofty/src/ebml/tag/tag.rs

@@ -1,6 +1,8 @@
 use super::simple_tag::SimpleTag;
 use super::target::{Target, TargetDescriptor, TargetType};
 
+use std::borrow::Cow;
+
 /// A single metadata descriptor.
 ///
 /// This represents a `\Segment\Tags\Tag` element in the EBML tree. It contains a single [`Target`] and
@@ -119,3 +121,11 @@ impl Tag<'static> {
 		self.simple_tags.extend(other.simple_tags);
 	}
 }
+
+pub(crate) struct TagRef<'a, I>
+where
+	I: Iterator<Item = Cow<'a, SimpleTag<'a>>>,
+{
+	pub(crate) targets: TargetDescriptor<'a>,
+	pub(crate) simple_tags: &'a mut I,
+}

lofty/src/ebml/tag/write/elements/mod.rs

@@ -1,3 +1,6 @@
+#![allow(non_upper_case_globals)]
+
 pub(super) mod attached_file;
-mod simple_tag;
+pub(super) mod simple_tag;
+pub(super) mod tags;
 pub(super) mod target;

lofty/src/ebml/tag/write/elements/tags.rs

@@ -0,0 +1,36 @@
+use crate::ebml::tag::write::{write_element, ElementWriterCtx, WriteableElement};
+use crate::ebml::{ElementId, SimpleTag, TagRef};
+use crate::io::FileLike;
+
+use std::borrow::Cow;
+use std::io::Cursor;
+
+impl<'a, I> WriteableElement for TagRef<'a, I>
+where
+	I: Iterator<Item = Cow<'a, SimpleTag<'a>>>,
+{
+	const ID: ElementId = ElementId(0x7373);
+
+	fn write_element<F: FileLike>(
+		&self,
+		ctx: ElementWriterCtx,
+		writer: &mut F,
+	) -> crate::error::Result<()> {
+		let mut element_children = Cursor::new(Vec::new());
+		self.targets.write_element(ctx, &mut element_children)?;
+
+		// TODO
+		// for simple_tag in self.simple_tags {
+		// 	simple_tag.write_element(ctx, &mut element_children)?;
+		// }
+
+		write_element(
+			ctx,
+			Self::ID,
+			&element_children.get_ref().as_slice(),
+			writer,
+		)?;
+
+		Ok(())
+	}
+}

lofty/tests/fuzz/ebmlfile_read_from.rs

@@ -0,0 +1 @@
+