refactor(lsp): use deno_ast and cache swc ASTs (#11780)

cli/lsp/document_source.rs

@@ -0,0 +1,76 @@
+use deno_ast::swc::common::BytePos;
+use deno_ast::Diagnostic;
+use deno_ast::MediaType;
+use deno_ast::ParsedSource;
+use deno_ast::SourceTextInfo;
+use deno_core::ModuleSpecifier;
+use once_cell::sync::OnceCell;
+use std::sync::Arc;
+
+use super::analysis;
+use super::text::LineIndex;
+
+#[derive(Debug)]
+struct DocumentSourceInner {
+  specifier: ModuleSpecifier,
+  media_type: MediaType,
+  text_info: SourceTextInfo,
+  parsed_module: OnceCell<Result<ParsedSource, Diagnostic>>,
+  line_index: LineIndex,
+}
+
+/// Immutable information about a document.
+#[derive(Debug, Clone)]
+pub struct DocumentSource {
+  inner: Arc<DocumentSourceInner>,
+}
+
+impl DocumentSource {
+  pub fn new(
+    specifier: &ModuleSpecifier,
+    media_type: MediaType,
+    text: Arc<String>,
+    line_index: LineIndex,
+  ) -> Self {
+    Self {
+      inner: Arc::new(DocumentSourceInner {
+        specifier: specifier.clone(),
+        media_type,
+        text_info: SourceTextInfo::new(BytePos(0), text),
+        parsed_module: OnceCell::new(),
+        line_index,
+      }),
+    }
+  }
+
+  pub fn text_info(&self) -> &SourceTextInfo {
+    &self.inner.text_info
+  }
+
+  pub fn line_index(&self) -> &LineIndex {
+    &self.inner.line_index
+  }
+
+  pub fn module(&self) -> Option<&Result<ParsedSource, Diagnostic>> {
+    let is_parsable = matches!(
+      self.inner.media_type,
+      MediaType::JavaScript
+        | MediaType::Jsx
+        | MediaType::TypeScript
+        | MediaType::Tsx
+        | MediaType::Dts,
+    );
+    if is_parsable {
+      // lazily parse the module
+      Some(self.inner.parsed_module.get_or_init(|| {
+        analysis::parse_module(
+          &self.inner.specifier,
+          self.inner.text_info.clone(),
+          self.inner.media_type,
+        )
+      }))
+    } else {
+      None
+    }
+  }
+}