ci: reduce Rust cache size and duplicate keys

.github/actions/setup-rust/action.yml

@@ -36,8 +36,19 @@ runs:
         restore-cache: false
         target-dir: ${{ inputs.target-dir }}
 
+    - name: Normalize Rust cache environment
+      if: inputs.restore-cache == 'true'
+      shell: bash
+      run: node "$SETUP_RUST_ACTION_PATH/prepare-cache.mjs"
+      env:
+        SETUP_RUST_ACTION_PATH: ${{ github.action_path }}
+
     - uses: Swatinem/rust-cache@6323deb102c322ba6fcbdcafc7e3dddab59af2b6 # v2.9.2
       if: inputs.restore-cache == 'true'
+      env:
+        # Spend a few more seconds when saving to reduce every later download.
+        # This also applies to the action's post step, which creates the archive.
+        ZSTD_CLEVEL: '9'
       with:
         # Existing entries are immutable and can lack dependencies removed
         # by v2.9.1. Start a new namespace so the corrected action saves them.

.github/actions/setup-rust/prepare-cache.mjs

@@ -0,0 +1,45 @@
+import { execFileSync } from 'node:child_process';
+import { appendFileSync } from 'node:fs';
+import { homedir } from 'node:os';
+import { join, resolve } from 'node:path';
+import { pathToFileURL } from 'node:url';
+
+export function prepareRustCache({
+  run = (args) => execFileSync('rustup', args, { encoding: 'utf8' }).trim(),
+  env = process.env,
+  home = homedir(),
+} = {}) {
+  const active = run(['show', 'active-toolchain']).split(/\s+/)[0];
+  const installed = run(['toolchain', 'list', '--quiet']).split(/\s+/).filter(Boolean);
+  if (!active || !installed.includes(active)) {
+    throw new Error('The active Rust toolchain must be installed before cache setup');
+  }
+
+  // Cached jobs build with the workspace toolchain. rust-cache also hashes
+  // unused toolchains from the runner image, which vary across image updates.
+  // Keep the workspace compiler as the default before removing those extras.
+  run(['default', active]);
+  for (const toolchain of installed) {
+    if (toolchain !== active) {
+      run(['toolchain', 'uninstall', toolchain]);
+    }
+  }
+
+  // GitHub runners leave these defaults unset; Namespace sets them explicitly.
+  // rust-cache hashes nonempty environment variables, so use the same values.
+  // Preserve custom paths, including Windows Dev Drives.
+  return {
+    CARGO_HOME: env.CARGO_HOME || join(home, '.cargo'),
+    RUSTUP_HOME: env.RUSTUP_HOME || join(home, '.rustup'),
+  };
+}
+
+if (process.argv[1] && import.meta.url === pathToFileURL(resolve(process.argv[1])).href) {
+  const paths = prepareRustCache();
+  appendFileSync(
+    process.env.GITHUB_ENV,
+    Object.entries(paths)
+      .map(([key, value]) => `${key}=${value}\n`)
+      .join(''),
+  );
+}

.github/benchmark/rust-cache-compression/results.json

@@ -0,0 +1,101 @@
+{
+  "run": "https://github.com/voidzero-dev/vite-plus/actions/runs/39453647412",
+  "benchmark_commit": "31b8c67f1",
+  "source_commit": "0cbfb6d6bf24ceb8b99b8645c613f4d27fadf359",
+  "scope": "Restored main cache payloads: Cargo registry, Cargo git, and target. Excludes Cargo bin and its installation metadata. Each level compresses the same tar stream; SHA-256 of the decompressed bytes must match. One timing sample per level and job.",
+  "samples": [
+    {
+      "name": "linux-lint",
+      "source_bytes": 1776875520,
+      "source_sha256": "fbb377c81a91bef220e723ec4483e273e1850ae997d395443f3a077a705e48a8",
+      "paths": [
+        "/home/runner/.cargo/registry",
+        "/home/runner/.cargo/git",
+        "/home/runner/work/vite-plus/vite-plus/target"
+      ],
+      "zstd": "*** Zstandard CLI (64-bit) v1.5.7, by Yann Collet ***",
+      "samples": [
+        {
+          "level": 3,
+          "bytes": 513505284,
+          "compress_seconds": 2.6415996039999996,
+          "decompress_and_hash_seconds": 1.804909391999999
+        },
+        {
+          "level": 6,
+          "bytes": 493021878,
+          "compress_seconds": 6.507066184999999,
+          "decompress_and_hash_seconds": 1.7851912130000045
+        },
+        {
+          "level": 9,
+          "bytes": 457478458,
+          "compress_seconds": 9.765904976000002,
+          "decompress_and_hash_seconds": 1.7819855579999881
+        }
+      ]
+    },
+    {
+      "name": "linux-test",
+      "source_bytes": 3391518720,
+      "source_sha256": "e8b067a35ef016642e388aaf3dfb4e30e94018ea6ebbd68a7a7f56f6d08f5b60",
+      "paths": [
+        "/home/runner/.cargo/registry",
+        "/home/runner/.cargo/git",
+        "/home/runner/work/vite-plus/vite-plus/target"
+      ],
+      "zstd": "*** Zstandard CLI (64-bit) v1.5.7, by Yann Collet ***",
+      "samples": [
+        {
+          "level": 3,
+          "bytes": 845734789,
+          "compress_seconds": 6.381204795999992,
+          "decompress_and_hash_seconds": 4.233851232000006
+        },
+        {
+          "level": 6,
+          "bytes": 805789463,
+          "compress_seconds": 15.717300264999977,
+          "decompress_and_hash_seconds": 4.200105497999999
+        },
+        {
+          "level": 9,
+          "bytes": 705263026,
+          "compress_seconds": 22.005928431,
+          "decompress_and_hash_seconds": 4.200576061999982
+        }
+      ]
+    },
+    {
+      "name": "mac-test",
+      "source_bytes": 4381358080,
+      "source_sha256": "40ff23bc23b03fc05171ba01b9ce4896e4821429c6807b7bebc8bcdddaf23abd",
+      "paths": [
+        "/Users/runner/.cargo/registry",
+        "/Users/runner/.cargo/git",
+        "/Users/runner/work/vite-plus/vite-plus/target"
+      ],
+      "zstd": "*** Zstandard CLI (64-bit) v1.5.7, by Yann Collet ***",
+      "samples": [
+        {
+          "level": 3,
+          "bytes": 1127662872,
+          "compress_seconds": 1.3496105419999935,
+          "decompress_and_hash_seconds": 3.172481375000004
+        },
+        {
+          "level": 6,
+          "bytes": 1076874052,
+          "compress_seconds": 3.5355037500000037,
+          "decompress_and_hash_seconds": 3.1357934999999912
+        },
+        {
+          "level": 9,
+          "bytes": 926059853,
+          "compress_seconds": 5.343295082999987,
+          "decompress_and_hash_seconds": 2.978743083000012
+        }
+      ]
+    }
+  ]
+}

.github/scripts/__tests__/prepare-rust-cache.mjs

@@ -0,0 +1,71 @@
+import assert from 'node:assert/strict';
+import { test } from 'node:test';
+
+import { prepareRustCache } from '../../actions/setup-rust/prepare-cache.mjs';
+
+const active = 'nightly-2026-08-02-x86_64-unknown-linux-gnu';
+
+function fixture(installed, env = {}) {
+  const commands = [];
+  const paths = prepareRustCache({
+    env,
+    home: '/home/runner',
+    run(args) {
+      commands.push(args);
+      if (args[0] === 'show') {
+        return `${active} (overridden by '/workspace/rust-toolchain.toml')`;
+      }
+      if (args[1] === 'list') {
+        return installed.join('\n');
+      }
+      return '';
+    },
+  });
+  return { commands, paths };
+}
+
+test('keeps the pinned compiler and removes unused runner toolchains', () => {
+  const extra = ['stable-x86_64-unknown-linux-gnu', '1.99.0-x86_64-unknown-linux-gnu'];
+  const { commands } = fixture([...extra, active]);
+  assert.deepEqual(commands.slice(2), [
+    ['default', active],
+    ...extra.map((toolchain) => ['toolchain', 'uninstall', toolchain]),
+  ]);
+});
+
+test('does not uninstall a toolchain when only the active one is installed', () => {
+  const { commands } = fixture([active]);
+  assert.deepEqual(commands.slice(2), [['default', active]]);
+});
+
+test('unset and explicit default paths produce the same cache environment', () => {
+  const implicit = fixture([active]);
+  const explicit = fixture([active], {
+    CARGO_HOME: '/home/runner/.cargo',
+    RUSTUP_HOME: '/home/runner/.rustup',
+  });
+  assert.deepEqual(implicit.paths, explicit.paths);
+});
+
+test('preserves custom Cargo and Rustup paths', () => {
+  const paths = {
+    CARGO_HOME: 'D:\\Dev Drive\\.cargo',
+    RUSTUP_HOME: 'D:\\Dev Drive\\.rustup',
+  };
+  assert.deepEqual(fixture([active], paths).paths, paths);
+});
+
+test('fails before changing toolchains when the active compiler is missing', () => {
+  const commands = [];
+  assert.throws(
+    () =>
+      prepareRustCache({
+        run(args) {
+          commands.push(args);
+          return args[0] === 'show' ? active : 'stable-x86_64-unknown-linux-gnu';
+        },
+      }),
+    /must be installed/,
+  );
+  assert.equal(commands.length, 2);
+});

.github/workflows/ci.yml

@@ -326,6 +326,9 @@ jobs:
       - uses: taiki-e/checkout-action@7d1e50e93dc4fb3bba58f85018fadf77898aee8b # v1.4.2
       - uses: ./.github/actions/clone
 
+      - name: Test Rust cache helpers
+        run: node --test .github/scripts/__tests__/*rust-cache*.mjs
+
       - uses: ./.github/actions/setup-ci-node
 
       - uses: ./.github/actions/setup-rust