foster/denoland-deno
1
0
Fork 0
mirror of https://github.com/denoland/deno.git synced 2024-12-21 23:04:45 -05:00
Code Issues Packages 1 Wiki Activity
denoland-deno/cli/tsc
History
Nathan Whitaker b74a4f29f2
perf(lsp): Don't retain SourceFileObjects in sourceFileCache longer than necessary (#23258) 
The TS language service requests source files via
[getSourceFile](7a25fd5ef0/cli/tsc/99_main_compiler.js (L560)).
In that function, we [unconditionally
add](7a25fd5ef0/cli/tsc/99_main_compiler.js (L613-L614))
the source file to our sourceFileCache. The issue is that we only remove
things from that cache if the source file [becomes out of
date](7a25fd5ef0/cli/tsc/99_main_compiler.js (L777-L783)).
For files that don't get changed, we keep them in the cache
indefinitely. So sometimes we keep SourceFile objects from being GC'ed
because they're retained in our cache, even though TS doesn't refer to
them any more. I see this in pretty much all of the heap snapshots I've
taken.

---

The fix here is pretty direct - just store weak references to the
sourcefiles in the cache. It doesn't really change our caching behavior,
it just prevents us from being the only retainer of a `SourceFile`. I
also split the `sourceFileCache` into a separate cache just for assets,
as we rely on those being alive.

The simpler fix is to only cache assets, but presumably that has a perf
impact.

---
In local testing, this PR reduced the size of the JS heap by about 1 GB
when using `deno lsp` in the Typescript repo.
2024-04-06 19:22:37 -07:00
..
dts feat: type declarations for new Set methods (#23090) 2024-03-26 21:59:24 -04:00
00_typescript.js feat: TypeScript 5.4 (#23086) 2024-03-26 18:52:57 -04:00
99_main_compiler.js perf(lsp): Don't retain SourceFileObjects in sourceFileCache longer than necessary (#23258) 2024-04-06 19:22:37 -07:00
compiler.d.ts chore: update copyright to 2024 (#21753) 2024-01-01 19:58:21 +00:00
diagnostics.rs fix(check): ignore certain diagnostics in remote modules and when publishing (#23119) 2024-03-31 16:39:40 -04:00
mod.rs chore: upgrade deno_core (#22699) 2024-03-05 01:17:39 +00:00
README.md feat: TypeScript 5.4 (#23086) 2024-03-26 18:52:57 -04:00

README.md

tsc

This directory contains the typescript compiler and a small compiler host for the runtime snapshot.

How to upgrade TypeScript.

The files in this directory are mostly from the TypeScript repository. We currently (unfortunately) have a rather manual process for upgrading TypeScript. It works like this currently:

  1. Checkout denoland/TypeScript repo in a separate directory.
  2. Add Microsoft/TypeScript as a remote and fetch its latest tags
  3. Checkout a new branch based on this tag.
  4. Cherry pick the custom commit we made in a previous release to the new one.
  5. This commit has a "deno.ts" file in it. Read the instructions in it.
  6. Copy typescript.js into Deno repo.
  7. Copy d.ts files into dts directory.
  8. Review the copied files, removing and reverting what's necessary

So that might look something like this:

git clone https://github.com/denoland/TypeScript.git
cd typescript
git remote add upstream https://github.com/Microsoft/TypeScript
git fetch upstream
git checkout v3.9.7
git checkout -b branch_v3.9.7
git cherry pick <previous-release-branch-commit-we-did>
npm install
npx hereby
rsync built/local/typescript.js ~/src/deno/cli/tsc/00_typescript.js
rsync --exclude=protocol.d.ts --exclude=tsserverlibrary.d.ts --exclude=typescriptServices.d.ts built/local/*.d.ts ~/src/deno/cli/tsc/dts/