feat(dictionary): add serde support

src/format/chapter/chapter_mut.rs

@@ -56,8 +56,8 @@ impl<'a> ChapterMut<'a> {
 		// dictionary.set() allocates the AVDictionary the first time a key/value is
 		// inserted so we want to update the metadata dictionary afterwards
 		unsafe {
-			let dictionary = Dictionary::own(self.metadata().as_mut_ptr());
-			dictionary.as_mut().set(key.as_ref(), value.as_ref());
+			let mut dictionary = Dictionary::own(self.metadata().as_mut_ptr());
+			dictionary.set(key.as_ref(), value.as_ref());
 			(*self.as_mut_ptr()).metadata = dictionary.disown();
 		}
 	}

src/util/dictionary/owned.rs

@@ -1,6 +1,6 @@
 use std::{fmt, iter::FromIterator, ptr};
 
-use super::{immutable, mutable};
+use super::{immutable, mutable, Iter};
 use crate::ffi::*;
 
 pub struct Owned {
@@ -44,8 +44,8 @@ impl Owned {
 		unsafe { immutable::Ref::wrap(self.ptr) }
 	}
 
-	pub fn as_mut(&self) -> mutable::Ref {
-		unsafe { mutable::Ref::wrap(self.ptr) }
+	pub fn len(&self) -> usize {
+		self.as_ref().len()
 	}
 
 	pub fn iter(&self) -> Iter<'_> {
@@ -53,17 +53,22 @@ impl Owned {
 	}
 
 	pub fn set(&mut self, key: &str, value: &str) -> &mut Self {
-		self.as_mut().set(key, value);
+		unsafe {
+			let mut mutable = mutable::Ref::wrap(self.ptr);
+			mutable.set(key, value);
+			self.ptr = mutable.as_mut_ptr();
+		}
+
 		self
 	}
 }
 
 impl<'a> FromIterator<(&'a str, &'a str)> for Owned {
 	fn from_iter<T: IntoIterator<Item = (&'a str, &'a str)>>(iterator: T) -> Self {
-		let result = Owned::new();
+		let mut result = Owned::new();
 
 		for (key, value) in iterator {
-			result.as_mut().set(key, value);
+			result.set(key, value);
 		}
 
 		result
@@ -72,10 +77,10 @@ impl<'a> FromIterator<(&'a str, &'a str)> for Owned {
 
 impl<'a> FromIterator<&'a (&'a str, &'a str)> for Owned {
 	fn from_iter<T: IntoIterator<Item = &'a (&'a str, &'a str)>>(iterator: T) -> Self {
-		let result = Owned::new();
+		let mut result = Owned::new();
 
 		for &(key, value) in iterator {
-			result.as_mut().set(key, value);
+			result.set(key, value);
 		}
 
 		result
@@ -84,10 +89,10 @@ impl<'a> FromIterator<&'a (&'a str, &'a str)> for Owned {
 
 impl FromIterator<(String, String)> for Owned {
 	fn from_iter<T: IntoIterator<Item = (String, String)>>(iterator: T) -> Self {
-		let result = Owned::new();
+		let mut result = Owned::new();
 
 		for (key, value) in iterator {
-			result.as_mut().set(&key, &value);
+			result.set(&key, &value);
 		}
 
 		result
@@ -96,10 +101,10 @@ impl FromIterator<(String, String)> for Owned {
 
 impl<'a> FromIterator<&'a (String, String)> for Owned {
 	fn from_iter<T: IntoIterator<Item = &'a (String, String)>>(iterator: T) -> Self {
-		let result = Owned::new();
+		let mut result = Owned::new();
 
 		for &(ref key, ref value) in iterator {
-			result.as_mut().set(key, value);
+			result.set(key, value);
 		}
 
 		result
@@ -136,3 +141,58 @@ impl fmt::Debug for Owned {
 		unsafe { mutable::Ref::wrap(self.ptr) }.fmt(fmt)
 	}
 }
+
+#[cfg(feature = "serde")]
+mod serde {
+	use std::fmt;
+
+	use serde::{
+		de::{Deserialize, Deserializer, MapAccess, Visitor},
+		ser::{Serialize, SerializeMap, Serializer},
+	};
+
+	impl Serialize for super::Owned {
+		fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+		where
+			S: Serializer,
+		{
+			let mut map = serializer.serialize_map(Some(self.len()))?;
+			for (k, v) in self.iter() {
+				map.serialize_entry(k, v)?;
+			}
+			map.end()
+		}
+	}
+
+	struct DictionaryVisitor;
+
+	impl<'de> Visitor<'de> for DictionaryVisitor {
+		type Value = super::Owned;
+
+		fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+			formatter.write_str("an ffmpeg dictionary")
+		}
+
+		fn visit_map<M>(self, mut access: M) -> Result<Self::Value, M::Error>
+		where
+			M: MapAccess<'de>,
+		{
+			let mut map = super::Owned::new();
+
+			while let Some((key, value)) = access.next_entry()? {
+				map.set(key, value);
+			}
+
+			Ok(map)
+		}
+	}
+
+	impl<'de> Deserialize<'de> for super::Owned {
+		fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+		where
+			D: Deserializer<'de>,
+		{
+			deserializer.deserialize_map(DictionaryVisitor)
+		}
+	}
+}