feat: emit files on demand and fix racy emit (#15220)

1 files changed, 26 insertions, 128 deletions

diff --git a/cli/emit.rs b/cli/emit.rs
index 584593869..1d8ecca43 100644
--- a/cli/emit.rs
+++ b/cli/emit.rs
@@ -10,7 +10,7 @@ use crate::args::EmitConfigOptions;
 use crate::args::TsConfig;
 use crate::args::TypeCheckMode;
 use crate::cache::EmitCache;
-use crate::cache::SpecifierEmitCacheData;
+use crate::cache::FastInsecureHasher;
 use crate::cache::TypeCheckCache;
 use crate::colors;
 use crate::diagnostics::Diagnostics;
@@ -22,6 +22,7 @@ use crate::version;
 use deno_ast::swc::bundler::Hook;
 use deno_ast::swc::bundler::ModuleRecord;
 use deno_ast::swc::common::Span;
+use deno_ast::ParsedSource;
 use deno_core::error::AnyError;
 use deno_core::parking_lot::RwLock;
 use deno_core::serde::Deserialize;
@@ -32,14 +33,11 @@ use deno_core::serde_json;
 use deno_core::serde_json::json;
 use deno_core::ModuleSpecifier;
 use deno_graph::MediaType;
-use deno_graph::ModuleGraph;
 use deno_graph::ModuleGraphError;
 use deno_graph::ModuleKind;
 use deno_graph::ResolutionError;
-use std::collections::HashSet;
 use std::fmt;
 use std::sync::Arc;
-use std::time::Instant;
 
 /// A structure representing stats from an emit operation for a graph.
 #[derive(Clone, Debug, Default, Eq, PartialEq)]
@@ -116,8 +114,8 @@ pub enum TsConfigType {
   /// Return a configuration for bundling, using swc to emit the bundle. This is
   /// independent of type checking.
   Bundle,
-  /// Return a configuration to use tsc to type check and optionally emit. This
-  /// is independent of either bundling or just emitting via swc
+  /// Return a configuration to use tsc to type check. This
+  /// is independent of either bundling or emitting via swc.
   Check { lib: TsTypeLib },
   /// Return a configuration to use swc to emit single module files.
   Emit,
@@ -234,31 +232,30 @@ fn get_tsc_roots(
 /// A hashing function that takes the source code, version and optionally a
 /// user provided config and generates a string hash which can be stored to
 /// determine if the cached emit is valid or not.
-fn get_version(source_bytes: &[u8], config_bytes: &[u8]) -> String {
-  crate::checksum::gen(&[
-    source_bytes,
-    version::deno().as_bytes(),
-    config_bytes,
-  ])
+pub fn get_source_hash(source_text: &str, emit_options_hash: u64) -> u64 {
+  FastInsecureHasher::new()
+    .write_str(source_text)
+    .write_u64(emit_options_hash)
+    .finish()
 }
 
-/// Determine if a given module kind and media type is emittable or not.
-pub fn is_emittable(
-  kind: &ModuleKind,
-  media_type: &MediaType,
-  include_js: bool,
-) -> bool {
-  if matches!(kind, ModuleKind::Synthetic) {
-    return false;
-  }
-  match &media_type {
-    MediaType::TypeScript
-    | MediaType::Mts
-    | MediaType::Cts
-    | MediaType::Tsx
-    | MediaType::Jsx => true,
-    MediaType::JavaScript | MediaType::Mjs | MediaType::Cjs => include_js,
-    _ => false,
+pub fn emit_parsed_source(
+  cache: &EmitCache,
+  specifier: &ModuleSpecifier,
+  parsed_source: &ParsedSource,
+  emit_options: &deno_ast::EmitOptions,
+  emit_config_hash: u64,
+) -> Result<String, AnyError> {
+  let source_hash =
+    get_source_hash(parsed_source.text_info().text_str(), emit_config_hash);
+
+  if let Some(emit_code) = cache.get_emit_code(specifier, source_hash) {
+    Ok(emit_code)
+  } else {
+    let transpiled_source = parsed_source.transpile(emit_options)?;
+    debug_assert!(transpiled_source.source_map.is_none());
+    cache.set_emit_code(specifier, source_hash, &transpiled_source.text);
+    Ok(transpiled_source.text)
   }
 }
 
@@ -376,72 +373,6 @@ pub fn check(
   })
 }
 
-pub struct EmitOptions {
-  pub ts_config: TsConfig,
-  pub reload: bool,
-  pub reload_exclusions: HashSet<ModuleSpecifier>,
-}
-
-/// Given a module graph, emit any appropriate modules and cache them.
-// TODO(nayeemrmn): This would ideally take `GraphData` like
-// `check()`, but the AST isn't stored in that. Cleanup.
-pub fn emit(
-  graph: &ModuleGraph,
-  cache: &dyn EmitCache,
-  options: EmitOptions,
-) -> Result<CheckResult, AnyError> {
-  let start = Instant::now();
-  let config_bytes = options.ts_config.as_bytes();
-  let include_js = options.ts_config.get_check_js();
-  let emit_options = options.ts_config.into();
-
-  let mut emit_count = 0_u32;
-  let mut file_count = 0_u32;
-  for module in graph.modules() {
-    file_count += 1;
-    if !is_emittable(&module.kind, &module.media_type, include_js) {
-      continue;
-    }
-    let needs_reload =
-      options.reload && !options.reload_exclusions.contains(&module.specifier);
-    let version = get_version(
-      module.maybe_source.as_ref().map(|s| s.as_bytes()).unwrap(),
-      &config_bytes,
-    );
-    let is_valid = cache
-      .get_source_hash(&module.specifier)
-      .map_or(false, |v| v == version);
-    if is_valid && !needs_reload {
-      continue;
-    }
-    let transpiled_source = module
-      .maybe_parsed_source
-      .as_ref()
-      .map(|source| source.transpile(&emit_options))
-      .unwrap()?;
-    emit_count += 1;
-    cache.set_emit_data(
-      module.specifier.clone(),
-      SpecifierEmitCacheData {
-        source_hash: version,
-        text: transpiled_source.text,
-        map: transpiled_source.source_map,
-      },
-    )?;
-  }
-
-  let stats = Stats(vec![
-    ("Files".to_string(), file_count),
-    ("Emitted".to_string(), emit_count),
-    ("Total time".to_string(), start.elapsed().as_millis() as u32),
-  ]);
-
-  Ok(CheckResult {
-    diagnostics: Diagnostics::default(),
-    stats,
-  })
-}
-
 enum CheckHashResult {
   Hash(u64),
   NoFiles,
@@ -624,36 +555,3 @@ impl From<TsConfig> for deno_ast::EmitOptions {
     }
   }
 }
-
-#[cfg(test)]
-mod tests {
-  use super::*;
-
-  #[test]
-  fn test_is_emittable() {
-    assert!(is_emittable(
-      &ModuleKind::Esm,
-      &MediaType::TypeScript,
-      false
-    ));
-    assert!(!is_emittable(
-      &ModuleKind::Synthetic,
-      &MediaType::TypeScript,
-      false
-    ));
-    assert!(!is_emittable(&ModuleKind::Esm, &MediaType::Dts, false));
-    assert!(!is_emittable(&ModuleKind::Esm, &MediaType::Dcts, false));
-    assert!(!is_emittable(&ModuleKind::Esm, &MediaType::Dmts, false));
-    assert!(is_emittable(&ModuleKind::Esm, &MediaType::Tsx, false));
-    assert!(!is_emittable(
-      &ModuleKind::Esm,
-      &MediaType::JavaScript,
-      false
-    ));
-    assert!(!is_emittable(&ModuleKind::Esm, &MediaType::Cjs, false));
-    assert!(!is_emittable(&ModuleKind::Esm, &MediaType::Mjs, false));
-    assert!(is_emittable(&ModuleKind::Esm, &MediaType::JavaScript, true));
-    assert!(is_emittable(&ModuleKind::Esm, &MediaType::Jsx, false));
-    assert!(!is_emittable(&ModuleKind::Esm, &MediaType::Json, false));
-  }
-}