perf: better source map struct

Cargo.toml

@@ -30,7 +30,7 @@ path = "benches/bench.rs"
 harness = false
 
 [dependencies]
-serde = { version = "1", features = ["derive"] }
+serde = { version = "1", features = ["derive", "rc"] }
 serde_json = "1"
 dyn-clone = "1"
 rustc-hash = "1"

src/cached_source.rs

@@ -224,8 +224,7 @@ mod tests {
         value: "\nconsole.log(1);\n".to_string(),
         name: "index.js".to_string(),
         source_map: SourceMap::new(
-          None,
-          ";AACA".to_string(),
+          ";AACA",
           vec!["index.js".into()],
           vec!["// DELETE IT\nconsole.log(1)".into()],
           vec![],

src/helpers.rs

@@ -23,9 +23,9 @@ pub fn get_map<'a, S: StreamChunks<'a>>(
   options: &'a MapOptions,
 ) -> Option<SourceMap> {
   let mut mappings_encoder = create_encoder(options.columns);
-  let mut sources: Vec<Cow<'static, str>> = Vec::new();
-  let mut sources_content: Vec<Cow<'static, str>> = Vec::new();
-  let mut names: Vec<Cow<'static, str>> = Vec::new();
+  let mut sources: Vec<String> = Vec::new();
+  let mut sources_content: Vec<String> = Vec::new();
+  let mut names: Vec<String> = Vec::new();
 
   stream.stream_chunks(
     &MapOptions {
@@ -40,12 +40,12 @@ pub fn get_map<'a, S: StreamChunks<'a>>(
     &mut |source_index, source, source_content| {
       let source_index = source_index as usize;
       if sources.len() <= source_index {
-        sources.resize(source_index + 1, Cow::Borrowed(""));
+        sources.resize(source_index + 1, "".to_string());
       }
       sources[source_index] = source.to_string().into();
       if let Some(source_content) = source_content {
         if sources_content.len() <= source_index {
-          sources_content.resize(source_index + 1, Cow::Borrowed(""));
+          sources_content.resize(source_index + 1, "".to_string());
         }
         sources_content[source_index] = source_content.to_string().into();
       }
@@ -54,14 +54,14 @@ pub fn get_map<'a, S: StreamChunks<'a>>(
     &mut |name_index, name| {
       let name_index = name_index as usize;
       if names.len() <= name_index {
-        names.resize(name_index + 1, Cow::Borrowed(""));
+        names.resize(name_index + 1, "".to_string());
       }
       names[name_index] = name.to_string().into();
     },
   );
   let mappings = mappings_encoder.drain();
   (!mappings.is_empty())
-    .then(|| SourceMap::new(None, mappings, sources, sources_content, names))
+    .then(|| SourceMap::new(mappings, sources, sources_content, names))
 }
 
 /// [StreamChunks] abstraction, see [webpack-sources source.streamChunks](https://github.com/webpack/webpack-sources/blob/9f98066311d53a153fdc7c633422a1d086528027/lib/helpers/streamChunks.js#L13).
@@ -1149,9 +1149,9 @@ pub fn stream_and_get_source_and_map<'a, S: StreamChunks<'a>>(
   on_name: OnName<'_, 'a>,
 ) -> (GeneratedInfo, Option<SourceMap>) {
   let mut mappings_encoder = create_encoder(options.columns);
-  let mut sources: Vec<Cow<'static, str>> = Vec::new();
-  let mut sources_content: Vec<Cow<'static, str>> = Vec::new();
-  let mut names: Vec<Cow<'static, str>> = Vec::new();
+  let mut sources: Vec<String> = Vec::new();
+  let mut sources_content: Vec<String> = Vec::new();
+  let mut names: Vec<String> = Vec::new();
 
   let generated_info = input_source.stream_chunks(
     options,
@@ -1188,7 +1188,6 @@ pub fn stream_and_get_source_and_map<'a, S: StreamChunks<'a>>(
     None
   } else {
     Some(SourceMap::new(
-      None,
       mappings,
       sources,
       sources_content,