update dependencies and rebuild

This fixes #64.

When Cargo is run in sparse-registry mode, it doesn't create
  ~/.cargo/registry/index/github.com-1ecc6299db9ec823/
directory.

.github/workflows/selftest.yml

@@ -0,0 +1,31 @@
+name: CI
+
+on: [push, pull_request]
+
+jobs:
+  selftest:
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+
+    name: Test Action on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          profile: minimal
+          override: true
+
+      - uses: ./
+        with:
+          cache-on-failure: true
+
+      - run: |
+          cargo install cargo-deny --locked
+          cargo check
+          cargo test

.gitignore

@@ -1 +1,2 @@
 node_modules
+/target

CHANGELOG.md

@@ -1,5 +1,27 @@
 # Changelog
 
+## 1.4.0
+
+- Clean both `debug` and `release` target directories.
+
+## 1.3.0
+
+- Use Rust toolchain file as additional cache key.
+- Allow for a configurable target-dir.
+
+## 1.2.0
+
+- Cache `~/.cargo/bin`.
+- Support for custom `$CARGO_HOME`.
+- Add a `cache-hit` output.
+- Add a new `sharedKey` option that overrides the automatic job-name based key.
+
+## 1.1.0
+
+- Add a new `working-directory` input.
+- Support caching git dependencies.
+- Lots of other improvements.
+
 ## 1.0.2
 
 - Don’t prune targets that have a different name from the crate, but do prune targets from the workspace.

Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+publish = false
+name = "rust-cache"
+version = "0.1.0"
+authors = ["Arpad Borsos <arpad.borsos@googlemail.com>"]
+edition = "2018"
+
+[dev-dependencies]
+reqwest = "0.11.0"
+actix-web = { git = "https://github.com/actix/actix-web.git", rev = "bd26083f333ecf63e3eb444748250364ce124f5e" }

LICENSE

@@ -0,0 +1,165 @@
+                   GNU LESSER GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+
+  This version of the GNU Lesser General Public License incorporates
+the terms and conditions of version 3 of the GNU General Public
+License, supplemented by the additional permissions listed below.
+
+  0. Additional Definitions.
+
+  As used herein, "this License" refers to version 3 of the GNU Lesser
+General Public License, and the "GNU GPL" refers to version 3 of the GNU
+General Public License.
+
+  "The Library" refers to a covered work governed by this License,
+other than an Application or a Combined Work as defined below.
+
+  An "Application" is any work that makes use of an interface provided
+by the Library, but which is not otherwise based on the Library.
+Defining a subclass of a class defined by the Library is deemed a mode
+of using an interface provided by the Library.
+
+  A "Combined Work" is a work produced by combining or linking an
+Application with the Library.  The particular version of the Library
+with which the Combined Work was made is also called the "Linked
+Version".
+
+  The "Minimal Corresponding Source" for a Combined Work means the
+Corresponding Source for the Combined Work, excluding any source code
+for portions of the Combined Work that, considered in isolation, are
+based on the Application, and not on the Linked Version.
+
+  The "Corresponding Application Code" for a Combined Work means the
+object code and/or source code for the Application, including any data
+and utility programs needed for reproducing the Combined Work from the
+Application, but excluding the System Libraries of the Combined Work.
+
+  1. Exception to Section 3 of the GNU GPL.
+
+  You may convey a covered work under sections 3 and 4 of this License
+without being bound by section 3 of the GNU GPL.
+
+  2. Conveying Modified Versions.
+
+  If you modify a copy of the Library, and, in your modifications, a
+facility refers to a function or data to be supplied by an Application
+that uses the facility (other than as an argument passed when the
+facility is invoked), then you may convey a copy of the modified
+version:
+
+   a) under this License, provided that you make a good faith effort to
+   ensure that, in the event an Application does not supply the
+   function or data, the facility still operates, and performs
+   whatever part of its purpose remains meaningful, or
+
+   b) under the GNU GPL, with none of the additional permissions of
+   this License applicable to that copy.
+
+  3. Object Code Incorporating Material from Library Header Files.
+
+  The object code form of an Application may incorporate material from
+a header file that is part of the Library.  You may convey such object
+code under terms of your choice, provided that, if the incorporated
+material is not limited to numerical parameters, data structure
+layouts and accessors, or small macros, inline functions and templates
+(ten or fewer lines in length), you do both of the following:
+
+   a) Give prominent notice with each copy of the object code that the
+   Library is used in it and that the Library and its use are
+   covered by this License.
+
+   b) Accompany the object code with a copy of the GNU GPL and this license
+   document.
+
+  4. Combined Works.
+
+  You may convey a Combined Work under terms of your choice that,
+taken together, effectively do not restrict modification of the
+portions of the Library contained in the Combined Work and reverse
+engineering for debugging such modifications, if you also do each of
+the following:
+
+   a) Give prominent notice with each copy of the Combined Work that
+   the Library is used in it and that the Library and its use are
+   covered by this License.
+
+   b) Accompany the Combined Work with a copy of the GNU GPL and this license
+   document.
+
+   c) For a Combined Work that displays copyright notices during
+   execution, include the copyright notice for the Library among
+   these notices, as well as a reference directing the user to the
+   copies of the GNU GPL and this license document.
+
+   d) Do one of the following:
+
+       0) Convey the Minimal Corresponding Source under the terms of this
+       License, and the Corresponding Application Code in a form
+       suitable for, and under terms that permit, the user to
+       recombine or relink the Application with a modified version of
+       the Linked Version to produce a modified Combined Work, in the
+       manner specified by section 6 of the GNU GPL for conveying
+       Corresponding Source.
+
+       1) Use a suitable shared library mechanism for linking with the
+       Library.  A suitable mechanism is one that (a) uses at run time
+       a copy of the Library already present on the user's computer
+       system, and (b) will operate properly with a modified version
+       of the Library that is interface-compatible with the Linked
+       Version.
+
+   e) Provide Installation Information, but only if you would otherwise
+   be required to provide such information under section 6 of the
+   GNU GPL, and only to the extent that such information is
+   necessary to install and execute a modified version of the
+   Combined Work produced by recombining or relinking the
+   Application with a modified version of the Linked Version. (If
+   you use option 4d0, the Installation Information must accompany
+   the Minimal Corresponding Source and Corresponding Application
+   Code. If you use option 4d1, you must provide the Installation
+   Information in the manner specified by section 6 of the GNU GPL
+   for conveying Corresponding Source.)
+
+  5. Combined Libraries.
+
+  You may place library facilities that are a work based on the
+Library side by side in a single library together with other library
+facilities that are not Applications and are not covered by this
+License, and convey such a combined library under terms of your
+choice, if you do both of the following:
+
+   a) Accompany the combined library with a copy of the same work based
+   on the Library, uncombined with any other library facilities,
+   conveyed under the terms of this License.
+
+   b) Give prominent notice with the combined library that part of it
+   is a work based on the Library, and explaining where to find the
+   accompanying uncombined form of the same work.
+
+  6. Revised Versions of the GNU Lesser General Public License.
+
+  The Free Software Foundation may publish revised and/or new versions
+of the GNU Lesser General Public License from time to time. Such new
+versions will be similar in spirit to the present version, but may
+differ in detail to address new problems or concerns.
+
+  Each version is given a distinguishing version number. If the
+Library as you received it specifies that a certain numbered version
+of the GNU Lesser General Public License "or any later version"
+applies to it, you have the option of following the terms and
+conditions either of that published version or of any later version
+published by the Free Software Foundation. If the Library as you
+received it does not specify a version number of the GNU Lesser
+General Public License, you may choose any version of the GNU Lesser
+General Public License ever published by the Free Software Foundation.
+
+  If the Library as you received it specifies that a proxy can decide
+whether future versions of the GNU Lesser General Public License shall
+apply, that proxy's public statement of acceptance of any version is
+permanent authorization for you to choose that version for the
+Library.

README.md

@@ -1,47 +1,111 @@
 # Rust Cache Action
 
-A GitHub Action that implements smart caching for rust/cargo projects
-
-## Inputs
-
-- `key` - An optional key for the `target` cache. This is useful in case you
-  have different jobs for test / check / clippy, etc
+A GitHub Action that implements smart caching for rust/cargo projects with
+sensible defaults.
 
 ## Example usage
 
 ```yaml
-- uses: Swatinem/rust-cache@v1
+- uses: actions/checkout@v2
+
+# selecting a toolchain either by action or manual `rustup` calls should happen
+# before the plugin, as it uses the current rustc version as its cache key
+- uses: actions-rs/toolchain@v1
   with:
-    key: test
+    profile: minimal
+    toolchain: stable
+
+- uses: Swatinem/rust-cache@v1
 ```
 
-## Specifics
+## Inputs
 
-This action tries to be better than just caching the following directories:
+: `key`
+An optional key that is added to the automatic cache key.
 
-```
-~/.cargo/registry
-~/.cargo/git
-target
-```
+: `sharedKey`
+An additional key that is stable over multiple jobs.
 
-It disables incremental compilation and only caches dependencies. The
-assumption is that we will likely recompile the own crate(s) anyway.
+: `working-directory`
+The working directory the action operates in, is case the cargo project is not
+located in the repo root.
 
-It also separates the cache into 4 groups, each treated differently:
+: `target-dir`
+The target directory that should be cleaned and persisted, defaults to `./target`.
 
-- Registry Index: `~/.cargo/registry/index/<registry>`:
+: `cache-on-failure`
+Cache even if the build fails, defaults to false
 
-  This is always restored from its latest snapshot, and persisted based on the
-  most recent revision.
+## Outputs
 
-- Registry Cache: `~/.cargo/registry/cache/<registry>`:
+: `cache-hit`
 
-  Automatically keyed by the lockfile/toml hash, and is being pruned to only
-  persist the dependencies that are being used.
+This is a boolean flag that will be set to `true` when there was an exact cache hit.
 
-- target: `./target`
+## Cache Effectiveness
 
-  Automatically keyed by the lockfile/toml hash, and is being pruned to only
-  persist the dependencies that are being used. This is especially throwing
-  away any intermediate artifacts.
+This action only caches the _dependencies_ of a crate, so is more effective if
+the dependency / own code ratio is higher.
+
+It is also most effective for repositories with a `Cargo.lock` file. Library
+repositories with only a `Cargo.toml` file have limited benefits, as cargo will
+_always_ use the most up-to-date dependency versions, which may not be cached.
+
+Usage with Stable Rust is most effective, as a cache is tied to the Rust version.
+Using it with Nightly Rust is less effective as it will throw away the cache every day.
+
+## Versioning
+
+I use the `v1` branch similar to `master` development, so if you want to have
+a more stable experience, please use a fixed revision or tag.
+
+## Cache Details
+
+This action currently caches the following files/directories:
+
+- `~/.cargo/bin`
+- `~/.cargo/registry/index`
+- `~/.cargo/registry/cache`
+- `~/.cargo/git`
+- `~/.cargo/.crates.toml`
+- `~/.cargo/.crates2.json`
+- `./target`
+
+This cache is automatically keyed by:
+
+- the github [`job_id`](https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_id),
+- the rustc release / host / hash, and
+- a hash of all `Cargo.lock` / `Cargo.toml` files found anywhere in the repository (if present).
+- a hash of all `rust-toolchain` / `rust-toolchain.toml` files in the root of the repository (if present).
+
+An additional input `key` can be provided if the builtin keys are not sufficient.
+
+Before being persisted, the cache is cleaned of:
+- Any files in `~/.cargo/bin` that were present before the action ran (for example `rustc`).
+- Dependencies that are no longer used.
+- Anything that is not a dependency.
+- Incremental build artifacts.
+- Any build artifacts with an `mtime` older than one week.
+
+In particular, the workspace crates themselves are not cached since doing so is
+[generally not effective](https://github.com/Swatinem/rust-cache/issues/37#issuecomment-944697938).
+For this reason, this action automatically sets `CARGO_INCREMENTAL=0` to disable
+incremental compilation, so that the Rust compiler doesn't waste time creating
+the additional artifacts required for incremental builds.
+
+The `~/.cargo/registry/src` directory is not cached since it is quicker for Cargo
+to recreate it from the compressed crate archives in `~/.cargo/registry/cache`.
+
+The action will try to restore from a previous `Cargo.lock` version as well, so
+lockfile updates should only re-build changed dependencies.
+
+Additionally, the action automatically works around
+[cargo#8603](https://github.com/rust-lang/cargo/issues/8603) /
+[actions/cache#403](https://github.com/actions/cache/issues/403) which would
+otherwise corrupt the cache on macOS builds.
+
+## Known issues
+
+- The cache cleaning process currently only runs against the build artifacts under
+  `./target/debug/`, so projects using release or cross-compiled builds will experience
+  larger cache sizes.

action.yml

@@ -1,15 +1,30 @@
 name: "Rust Cache"
-description: "A GitHub Action that implements smart caching for rust/cargo projects"
+description: "A GitHub Action that implements smart caching for rust/cargo projects with sensible defaults."
 author: "Arpad Borsos <arpad.borsos@googlemail.com>"
 inputs:
   key:
-    description: "An explicit key for restoring and saving the target cache"
+    description: "An additional key for the cache"
     required: false
+  sharedKey:
+    description: "An additional cache key that is stable over multiple jobs"
+    required: false
+  working-directory:
+    description: "The working directory this action should operate in"
+    required: false
+  target-dir:
+    description: "The target dir that should be cleaned and persisted, defaults to `./target`"
+    required: false
+  cache-on-failure:
+    description: "Cache even if the build fails. Defaults to false"
+    required: false
+outputs:
+  cache-hit:
+    description: "A boolean value that indicates an exact match was found"
 runs:
   using: "node12"
   main: "dist/restore/index.js"
   post: "dist/save/index.js"
-  post-if: "success()"
+  post-if: "success() || env.CACHE_ON_FAILURE == 'true'"
 branding:
   icon: "archive"
   color: "gray-dark"

package.json

@@ -1,8 +1,8 @@
 {
   "private": true,
   "name": "rust-cache",
-  "version": "1.0.2",
-  "description": "A GitHub Action that implements smart caching for rust/cargo projects",
+  "version": "1.4.0",
+  "description": "A GitHub Action that implements smart caching for rust/cargo projects with sensible defaults.",
   "keywords": [
     "actions",
     "rust",
@@ -17,20 +17,22 @@
   "bugs": {
     "url": "https://github.com/Swatinem/rust-cache/issues"
   },
-  "funding": "https://github.com/sponsors/Swatinem",
+  "funding": {
+    "url": "https://github.com/sponsors/Swatinem"
+  },
   "homepage": "https://github.com/Swatinem/rust-cache#readme",
   "dependencies": {
-    "@actions/cache": "^1.0.2",
-    "@actions/core": "^1.2.6",
-    "@actions/exec": "^1.0.4",
-    "@actions/glob": "^0.1.0",
-    "@actions/io": "^1.0.2"
+    "@actions/cache": "^3.0.0",
+    "@actions/core": "^1.6.0",
+    "@actions/exec": "^1.1.1",
+    "@actions/glob": "^0.3.0",
+    "@actions/io": "^1.1.2"
   },
   "devDependencies": {
-    "@vercel/ncc": "^0.24.1",
-    "typescript": "^4.0.3"
+    "@vercel/ncc": "^0.34.0",
+    "typescript": "4.7.4"
   },
   "scripts": {
-    "prepare": "ncc build -o dist/restore src/restore.ts && ncc build -o dist/save src/save.ts"
+    "prepare": "ncc build --target es2020 -o dist/restore src/restore.ts && ncc build --target es2020 -o dist/save src/save.ts"
   }
 }

src/common.ts

@@ -1,31 +1,44 @@
 import * as core from "@actions/core";
 import * as exec from "@actions/exec";
 import * as glob from "@actions/glob";
+import * as io from "@actions/io";
 import crypto from "crypto";
 import fs from "fs";
 import os from "os";
 import path from "path";
 
+process.on("uncaughtException", (e) => {
+  core.info(`[warning] ${e.message}`);
+  if (e.stack) {
+    core.info(e.stack);
+  }
+});
+
+const cwd = core.getInput("working-directory");
+// TODO: this could be read from .cargo config file directly
+const targetDir = core.getInput("target-dir") || "./target";
+if (cwd) {
+  process.chdir(cwd);
+}
+
+export const stateBins = "RUST_CACHE_BINS";
+export const stateKey = "RUST_CACHE_KEY";
+const stateHash = "RUST_CACHE_HASH";
+
 const home = os.homedir();
+const cargoHome = process.env.CARGO_HOME || path.join(home, ".cargo");
 export const paths = {
-  index: path.join(home, ".cargo/registry/index"),
-  cache: path.join(home, ".cargo/registry/cache"),
-  git: path.join(home, ".cargo/git/db"),
-  target: "target",
+  cargoHome,
+  index: path.join(cargoHome, "registry/index"),
+  cache: path.join(cargoHome, "registry/cache"),
+  git: path.join(cargoHome, "git"),
+  target: targetDir,
 };
 
 interface CacheConfig {
-  name: string;
-  path: string;
+  paths: Array<string>;
   key: string;
-  restoreKeys?: Array<string>;
-}
-
-interface Caches {
-  index: CacheConfig;
-  cache: CacheConfig;
-  // git: CacheConfig;
-  target: CacheConfig;
+  restoreKeys: Array<string>;
 }
 
 const RefKey = "GITHUB_REF";
@@ -34,51 +47,67 @@ export function isValidEvent(): boolean {
   return RefKey in process.env && Boolean(process.env[RefKey]);
 }
 
-export async function getCaches(): Promise<Caches> {
-  const rustKey = await getRustKey();
-  let lockHash = core.getState("lockHash");
+export async function getCacheConfig(): Promise<CacheConfig> {
+  let lockHash = core.getState(stateHash);
   if (!lockHash) {
     lockHash = await getLockfileHash();
-    core.saveState("lockHash", lockHash);
-  }
-  let targetKey = core.getInput("key");
-  if (targetKey) {
-    targetKey = `${targetKey}-`;
+    core.saveState(stateHash, lockHash);
   }
 
-  const registryIndex = `v0-registry-index`;
-  const registryCache = `v0-registry-cache`;
-  const target = `v0-target-${targetKey}${rustKey}`;
+  let key = `v0-rust-`;
+
+  const sharedKey = core.getInput("sharedKey");
+  if (sharedKey) {
+    key += `${sharedKey}-`;
+  } else {
+    const inputKey = core.getInput("key");
+    if (inputKey) {
+      key += `${inputKey}-`;
+    }
+
+    const job = process.env.GITHUB_JOB;
+    if (job) {
+      key += `${job}-`;
+    }
+  }
+
+  key += await getRustKey();
+
   return {
-    index: {
-      name: "Registry Index",
-      path: paths.index,
-      key: `${registryIndex}-`,
-      restoreKeys: [registryIndex],
-    },
-    cache: {
-      name: "Registry Cache",
-      path: paths.cache,
-      key: `${registryCache}-${lockHash}`,
-      restoreKeys: [registryCache],
-    },
-    // git: {
-    //   name: "Git Dependencies",
-    //   path: paths.git,
-    //   key: "git-db",
-    // },
-    target: {
-      name: "Target",
-      path: paths.target,
-      key: `${target}-${lockHash}`,
-      restoreKeys: [target],
-    },
+    paths: [
+      path.join(cargoHome, "bin"),
+      path.join(cargoHome, ".crates2.json"),
+      path.join(cargoHome, ".crates.toml"),
+      paths.git,
+      paths.cache,
+      paths.index,
+      paths.target,
+    ],
+    key: `${key}-${lockHash}`,
+    restoreKeys: [key],
   };
 }
 
+export async function getCargoBins(): Promise<Set<string>> {
+  try {
+    const { installs }: { installs: { [key: string]: { bins: Array<string> } } } = JSON.parse(
+      await fs.promises.readFile(path.join(paths.cargoHome, ".crates2.json"), "utf8"),
+    );
+    const bins = new Set<string>();
+    for (const pkg of Object.values(installs)) {
+      for (const bin of pkg.bins) {
+        bins.add(bin);
+      }
+    }
+    return bins;
+  } catch {
+    return new Set<string>();
+  }
+}
+
 async function getRustKey(): Promise<string> {
   const rustc = await getRustVersion();
-  return `${rustc.release}-${rustc.host}-${rustc["commit-hash"]}`;
+  return `${rustc.release}-${rustc.host}-${rustc["commit-hash"].slice(0, 12)}`;
 }
 
 interface RustVersion {
@@ -115,22 +144,10 @@ export async function getCmdOutput(
   return stdout;
 }
 
-export async function getRegistryName() {
-  const globber = await glob.create(`${paths.index}/**/.last-updated`, { followSymbolicLinks: false });
-  const files = await globber.glob();
-  if (files.length > 1) {
-    core.debug(`got multiple registries: "${files.join('", "')}"`);
-  }
-
-  const first = files.shift();
-  if (!first) {
-    return;
-  }
-  return path.basename(path.dirname(first));
-}
-
-async function getLockfileHash() {
-  const globber = await glob.create("**/Cargo.toml\n**/Cargo.lock", { followSymbolicLinks: false });
+async function getLockfileHash(): Promise<string> {
+  const globber = await glob.create("**/Cargo.toml\n**/Cargo.lock\nrust-toolchain\nrust-toolchain.toml", {
+    followSymbolicLinks: false,
+  });
   const files = await globber.glob();
   files.sort((a, b) => a.localeCompare(b));
 
@@ -140,5 +157,109 @@ async function getLockfileHash() {
       hasher.update(chunk);
     }
   }
-  return hasher.digest("hex");
+  return hasher.digest("hex").slice(0, 20);
+}
+
+export interface PackageDefinition {
+  name: string;
+  version: string;
+  path: string;
+  targets: Array<string>;
+}
+
+export type Packages = Array<PackageDefinition>;
+
+interface Meta {
+  packages: Array<{
+    name: string;
+    version: string;
+    manifest_path: string;
+    targets: Array<{ kind: Array<string>; name: string }>;
+  }>;
+}
+
+export async function getPackages(): Promise<Packages> {
+  const cwd = process.cwd();
+  const meta: Meta = JSON.parse(await getCmdOutput("cargo", ["metadata", "--all-features", "--format-version", "1"]));
+
+  return meta.packages
+    .filter((p) => !p.manifest_path.startsWith(cwd))
+    .map((p) => {
+      const targets = p.targets.filter((t) => t.kind[0] === "lib").map((t) => t.name);
+      return { name: p.name, version: p.version, targets, path: path.dirname(p.manifest_path) };
+    });
+}
+
+export async function cleanTarget(packages: Packages) {
+  await fs.promises.unlink(path.join(targetDir, "./.rustc_info.json"));
+
+  await cleanProfileTarget(packages, "debug");
+  await cleanProfileTarget(packages, "release");
+}
+
+async function cleanProfileTarget(packages: Packages, profile: string) {
+  try {
+    await fs.promises.access(path.join(targetDir, profile));
+  } catch {
+    return;
+  }
+
+  await io.rmRF(path.join(targetDir, profile, "./examples"));
+  await io.rmRF(path.join(targetDir, profile, "./incremental"));
+
+  let dir: fs.Dir;
+  // remove all *files* from the profile directory
+  dir = await fs.promises.opendir(path.join(targetDir, profile));
+  for await (const dirent of dir) {
+    if (dirent.isFile()) {
+      await rm(dir.path, dirent);
+    }
+  }
+
+  const keepPkg = new Set(packages.map((p) => p.name));
+  await rmExcept(path.join(targetDir, profile, "./build"), keepPkg);
+  await rmExcept(path.join(targetDir, profile, "./.fingerprint"), keepPkg);
+
+  const keepDeps = new Set(
+    packages.flatMap((p) => {
+      const names = [];
+      for (const n of [p.name, ...p.targets]) {
+        const name = n.replace(/-/g, "_");
+        names.push(name, `lib${name}`);
+      }
+      return names;
+    }),
+  );
+  await rmExcept(path.join(targetDir, profile, "./deps"), keepDeps);
+}
+
+const oneWeek = 7 * 24 * 3600 * 1000;
+
+export async function rmExcept(dirName: string, keepPrefix: Set<string>) {
+  const dir = await fs.promises.opendir(dirName);
+  for await (const dirent of dir) {
+    let name = dirent.name;
+    const idx = name.lastIndexOf("-");
+    if (idx !== -1) {
+      name = name.slice(0, idx);
+    }
+    const fileName = path.join(dir.path, dirent.name);
+    const { mtime } = await fs.promises.stat(fileName);
+    // we don’t really know
+    if (!keepPrefix.has(name) || Date.now() - mtime.getTime() > oneWeek) {
+      await rm(dir.path, dirent);
+    }
+  }
+}
+
+export async function rm(parent: string, dirent: fs.Dirent) {
+  try {
+    const fileName = path.join(parent, dirent.name);
+    core.debug(`deleting "${fileName}"`);
+    if (dirent.isFile()) {
+      await fs.promises.unlink(fileName);
+    } else if (dirent.isDirectory()) {
+      await io.rmRF(fileName);
+    }
+  } catch {}
 }

src/main.rs

@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}

src/restore.ts

@@ -1,41 +1,56 @@
 import * as cache from "@actions/cache";
 import * as core from "@actions/core";
-import { getCaches, isValidEvent } from "./common";
+import { cleanTarget, getCacheConfig, getCargoBins, getPackages, stateBins, stateKey } from "./common";
 
 async function run() {
-  if (!isValidEvent()) {
+  if (!cache.isFeatureAvailable()) {
+    setCacheHitOutput(false);
     return;
   }
 
   try {
+    var cacheOnFailure = core.getInput("cache-on-failure").toLowerCase();
+    if (cacheOnFailure !== "true") {
+      cacheOnFailure = "false";
+    }
+    core.exportVariable("CACHE_ON_FAILURE", cacheOnFailure);
     core.exportVariable("CARGO_INCREMENTAL", 0);
 
-    const caches = await getCaches();
-    for (const [type, { name, path, key, restoreKeys }] of Object.entries(caches)) {
-      const start = Date.now();
-      core.startGroup(`Restoring ${name}…`);
-      core.info(`Restoring to path "${path}".`);
-      core.info(`Using keys:\n    ${[key, ...restoreKeys].join("\n    ")}`);
-      try {
-        const restoreKey = await cache.restoreCache([path], key, restoreKeys);
-        if (restoreKey) {
-          core.info(`Restored from cache key "${restoreKey}".`);
-          core.saveState(type, restoreKey);
-        } else {
-          core.info("No cache found.");
-        }
-      } catch (e) {
-        core.info(`[warning] ${e.message}`);
+    const { paths, key, restoreKeys } = await getCacheConfig();
+
+    const bins = await getCargoBins();
+    core.saveState(stateBins, JSON.stringify([...bins]));
+
+    core.info(`Restoring paths:\n    ${paths.join("\n    ")}`);
+    core.info(`In directory:\n    ${process.cwd()}`);
+    core.info(`Using keys:\n    ${[key, ...restoreKeys].join("\n    ")}`);
+    const restoreKey = await cache.restoreCache(paths, key, restoreKeys);
+    if (restoreKey) {
+      core.info(`Restored from cache key "${restoreKey}".`);
+      core.saveState(stateKey, restoreKey);
+
+      if (restoreKey !== key) {
+        // pre-clean the target directory on cache mismatch
+        const packages = await getPackages();
+
+        await cleanTarget(packages);
       }
-      const duration = Math.round((Date.now() - start) / 1000);
-      if (duration) {
-        core.info(`Took ${duration}s.`);
-      }
-      core.endGroup();
+
+      setCacheHitOutput(restoreKey === key);
+    } else {
+      core.info("No cache found.");
+
+      setCacheHitOutput(false);
     }
   } catch (e) {
-    core.info(`[warning] ${e.message}`);
+    setCacheHitOutput(false);
+
+    core.info(`[warning] ${(e as any).stack}`);
   }
 }
 
+function setCacheHitOutput(cacheHit: boolean): void {
+  core.setOutput("cache-hit", cacheHit.toString());
+}
+
 run();

src/save.ts

@@ -1,162 +1,165 @@
 import * as cache from "@actions/cache";
 import * as core from "@actions/core";
 import * as exec from "@actions/exec";
+import * as glob from "@actions/glob";
 import * as io from "@actions/io";
 import fs from "fs";
 import path from "path";
-import { getCaches, getCmdOutput, getRegistryName, isValidEvent, paths } from "./common";
+import {
+  cleanTarget,
+  getCacheConfig,
+  getCargoBins,
+  getPackages,
+  Packages,
+  paths,
+  rm,
+  stateBins,
+  stateKey,
+} from "./common";
 
 async function run() {
-  if (!isValidEvent()) {
+  if (!cache.isFeatureAvailable()) {
     return;
   }
 
   try {
-    const caches = await getCaches();
-    const registryName = await getRegistryName();
-    const packages = await getPackages();
+    const { paths: savePaths, key } = await getCacheConfig();
+
+    if (core.getState(stateKey) === key) {
+      core.info(`Cache up-to-date.`);
+      return;
+    }
 
     // TODO: remove this once https://github.com/actions/toolkit/pull/553 lands
     await macOsWorkaround();
 
-    await pruneTarget(packages);
+    const registryName = await getRegistryName();
+    const packages = await getPackages();
 
     if (registryName) {
-      // save the index based on its revision
-      const indexRef = await getIndexRef(registryName);
-      caches.index.key += indexRef;
-      await io.rmRF(path.join(paths.index, registryName, ".cache"));
-
-      await pruneRegistryCache(registryName, packages);
-    } else {
-      delete (caches as any).index;
-      delete (caches as any).cache;
-    }
-
-    for (const [type, { name, path, key }] of Object.entries(caches)) {
-      if (core.getState(type) === key) {
-        core.info(`${name} up-to-date.`);
-        continue;
-      }
-      const start = Date.now();
-      core.startGroup(`Saving ${name}…`);
-      core.info(`Saving path "${path}".`);
-      core.info(`Using key "${key}".`);
       try {
-        await cache.saveCache([path], key);
+        await cleanRegistry(registryName, packages);
       } catch (e) {
-        core.info(`[warning] ${e.message}`);
+        core.info(`[warning] ${(e as any).stack}`);
       }
-      const duration = Math.round((Date.now() - start) / 1000);
-      if (duration) {
-        core.info(`Took ${duration}s.`);
-      }
-      core.endGroup();
     }
+
+    try {
+      await cleanBin();
+    } catch (e) {
+      core.info(`[warning] ${(e as any).stack}`);
+    }
+
+    try {
+      await cleanGit(packages);
+    } catch (e) {
+      core.info(`[warning] ${(e as any).stack}`);
+    }
+
+    try {
+      await cleanTarget(packages);
+    } catch (e) {
+      core.info(`[warning] ${(e as any).stack}`);
+    }
+
+    core.info(`Saving paths:\n    ${savePaths.join("\n    ")}`);
+    core.info(`In directory:\n    ${process.cwd()}`);
+    core.info(`Using key:\n    ${key}`);
+    await cache.saveCache(savePaths, key);
   } catch (e) {
-    core.info(`[warning] ${e.message}`);
+    core.info(`[warning] ${(e as any).stack}`);
   }
 }
 
 run();
 
-async function getIndexRef(registryName: string) {
-  const cwd = path.join(paths.index, registryName);
-  return (await getCmdOutput("git", ["rev-parse", "--short", "origin/master"], { cwd })).trim();
+async function getRegistryName(): Promise<string | null> {
+  const globber = await glob.create(`${paths.index}/**/.last-updated`, { followSymbolicLinks: false });
+  const files = await globber.glob();
+  if (files.length > 1) {
+    core.warning(`got multiple registries: "${files.join('", "')}"`);
+  }
+
+  const first = files.shift()!;
+  if (!first) {
+    return null;
+  }
+  return path.basename(path.dirname(first));
 }
 
-interface PackageDefinition {
-  name: string;
-  version: string;
-  targets: Array<string>;
+async function cleanBin() {
+  const bins = await getCargoBins();
+  const oldBins = JSON.parse(core.getState(stateBins));
+
+  for (const bin of oldBins) {
+    bins.delete(bin);
+  }
+
+  const dir = await fs.promises.opendir(path.join(paths.cargoHome, "bin"));
+  for await (const dirent of dir) {
+    if (dirent.isFile() && !bins.has(dirent.name)) {
+      await rm(dir.path, dirent);
+    }
+  }
 }
 
-type Packages = Array<PackageDefinition>;
+async function cleanRegistry(registryName: string, packages: Packages) {
+  await io.rmRF(path.join(paths.index, registryName, ".cache"));
 
-interface Meta {
-  packages: Array<{
-    name: string;
-    version: string;
-    manifest_path: string;
-    targets: Array<{ kind: Array<string>; name: string }>;
-  }>;
-}
-
-async function getPackages(): Promise<Packages> {
-  const cwd = process.cwd();
-  const meta: Meta = JSON.parse(await getCmdOutput("cargo", ["metadata", "--all-features", "--format-version", "1"]));
-
-  return meta.packages
-    .filter((p) => !p.manifest_path.startsWith(cwd))
-    .map((p) => {
-      const targets = p.targets.filter((t) => t.kind[0] === "lib").map((t) => t.name);
-      return { name: p.name, version: p.version, targets };
-    });
-}
-
-async function pruneRegistryCache(registryName: string, packages: Packages) {
   const pkgSet = new Set(packages.map((p) => `${p.name}-${p.version}.crate`));
 
   const dir = await fs.promises.opendir(path.join(paths.cache, registryName));
   for await (const dirent of dir) {
     if (dirent.isFile() && !pkgSet.has(dirent.name)) {
-      const fileName = path.join(dir.path, dirent.name);
-      await fs.promises.unlink(fileName);
-      core.debug(`deleting "${fileName}"`);
+      await rm(dir.path, dirent);
     }
   }
 }
 
-async function pruneTarget(packages: Packages) {
-  await fs.promises.unlink("./target/.rustc_info.json");
-  await io.rmRF("./target/debug/examples");
-  await io.rmRF("./target/debug/incremental");
+async function cleanGit(packages: Packages) {
+  const coPath = path.join(paths.git, "checkouts");
+  const dbPath = path.join(paths.git, "db");
+  const repos = new Map<string, Set<string>>();
+  for (const p of packages) {
+    if (!p.path.startsWith(coPath)) {
+      continue;
+    }
+    const [repo, ref] = p.path.slice(coPath.length + 1).split(path.sep);
+    const refs = repos.get(repo);
+    if (refs) {
+      refs.add(ref);
+    } else {
+      repos.set(repo, new Set([ref]));
+    }
+  }
+
+  // we have to keep both the clone, and the checkout, removing either will
+  // trigger a rebuild
+
   let dir: fs.Dir;
-
-  // remove all *files* from debug
-  dir = await fs.promises.opendir("./target/debug");
+  // clean the db
+  dir = await fs.promises.opendir(dbPath);
   for await (const dirent of dir) {
-    if (dirent.isFile()) {
-      const fileName = path.join(dir.path, dirent.name);
-      await fs.promises.unlink(fileName);
+    if (!repos.has(dirent.name)) {
+      await rm(dir.path, dirent);
     }
   }
 
-  const keepPkg = new Set(packages.map((p) => p.name));
-  await rmExcept("./target/debug/build", keepPkg);
-  await rmExcept("./target/debug/.fingerprint", keepPkg);
-
-  const keepDeps = new Set(
-    packages.flatMap((p) => {
-      const names = [];
-      for (const n of [p.name, ...p.targets]) {
-        const name = n.replace(/-/g, "_");
-        names.push(name, `lib${name}`);
-      }
-      return names;
-    }),
-  );
-  await rmExcept("./target/debug/deps", keepDeps);
-}
-
-const twoWeeks = 14 * 24 * 3600 * 1000;
-
-async function rmExcept(dirName: string, keepPrefix: Set<string>) {
-  const dir = await fs.promises.opendir(dirName);
+  // clean the checkouts
+  dir = await fs.promises.opendir(coPath);
   for await (const dirent of dir) {
-    let name = dirent.name;
-    const idx = name.lastIndexOf("-");
-    if (idx !== -1) {
-      name = name.slice(0, idx);
+    const refs = repos.get(dirent.name);
+    if (!refs) {
+      await rm(dir.path, dirent);
+      continue;
     }
-    const fileName = path.join(dir.path, dirent.name);
-    const { mtime } = await fs.promises.stat(fileName);
-    if (!keepPrefix.has(name) || Date.now() - mtime.getTime() > twoWeeks) {
-      core.debug(`deleting "${fileName}"`);
-      if (dirent.isFile()) {
-        await fs.promises.unlink(fileName);
-      } else if (dirent.isDirectory()) {
-        await io.rmRF(fileName);
+    if (!dirent.isDirectory()) {
+      continue;
+    }
+    const refsDir = await fs.promises.opendir(path.join(dir.path, dirent.name));
+    for await (const dirent of refsDir) {
+      if (!refs.has(dirent.name)) {
+        await rm(refsDir.path, dirent);
       }
     }
   }

tsconfig.json

@@ -4,7 +4,7 @@
     "diagnostics": true,
     "lib": ["esnext"],
 
-    "target": "es2017",
+    "target": "es2020",
 
     "resolveJsonModule": true,
     "moduleResolution": "node",