Use tries on all API calls

This reverts commit 6efe05572d.

.eslintrc.json

@@ -12,5 +12,12 @@
     "plugin:prettier/recommended",
     "prettier/@typescript-eslint"
   ],
-  "plugins": ["@typescript-eslint", "jest"]
+  "plugins": ["@typescript-eslint", "simple-import-sort", "jest"],
+  "rules": {
+    "import/first": "error",
+    "import/newline-after-import": "error",
+    "import/no-duplicates": "error",
+    "simple-import-sort/sort": "error",
+    "sort-imports": "off"
+  }
 }

.github/workflows/codeql.yml

@@ -0,0 +1,35 @@
+name: "Code Scanning - Action"
+
+on:
+  push:
+  schedule:
+    - cron: '0 0 * * 0'
+
+jobs:
+  CodeQL-Build:
+
+    strategy:
+      fail-fast: false
+
+
+    # CodeQL runs on ubuntu-latest, windows-latest, and macos-latest
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v2
+
+    # Initializes the CodeQL tools for scanning.
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v1
+      # Override language selection by uncommenting this and choosing your languages
+      # with:
+      #   languages: go, javascript, csharp, python, cpp, java
+
+    # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
+    # If this step fails, then you should remove it and run the build manually (see below).
+    - name: Autobuild
+      uses: github/codeql-action/autobuild@v1
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v1

.github/workflows/workflow.yml

@@ -13,41 +13,129 @@ on:
       - '**.md'
 
 jobs:
-  test:
-    name: Test on ${{ matrix.os }}
-
+  # Build and unit test
+  build:
     strategy:
       matrix:
         os: [ubuntu-latest, windows-latest, macOS-latest]
-
+      fail-fast: false
     runs-on: ${{ matrix.os }}
-
     steps:
-    - uses: actions/checkout@v1
-
-    - uses: actions/setup-node@v1
+    - name: Checkout
+      uses: actions/checkout@v2
+    - name: Setup Node.js
+      uses: actions/setup-node@v1
       with:
         node-version: '12.x'
-
-    - name: Get npm cache directory
+    - name: Determine npm cache directory
       id: npm-cache
       run: |
         echo "::set-output name=dir::$(npm config get cache)"
-
-    - uses: actions/cache@v1
+    - name: Restore npm cache
+      uses: actions/cache@v1
       with:
         path: ${{ steps.npm-cache.outputs.dir }}
         key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}
         restore-keys: |
           ${{ runner.os }}-node-
-
     - run: npm ci
-
     - name: Prettier Format Check
       run: npm run format-check
-
     - name: ESLint Check
       run: npm run lint
-
     - name: Build & Test
       run: npm run test
+
+  # End to end save and restore
+  test-save:
+    strategy:
+      matrix:
+        os: [ubuntu-latest, windows-latest, macOS-latest]
+      fail-fast: false
+    runs-on: ${{ matrix.os }}
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v2
+    - name: Generate files in working directory
+      shell: bash
+      run: __tests__/create-cache-files.sh ${{ runner.os }} test-cache
+    - name: Generate files outside working directory
+      shell: bash
+      run: __tests__/create-cache-files.sh ${{ runner.os }} ~/test-cache
+    - name: Save cache
+      uses: ./
+      with:
+        key: test-${{ runner.os }}-${{ github.run_id }}
+        path: |
+          test-cache
+          ~/test-cache
+  test-restore:
+    needs: test-save
+    strategy:
+      matrix:
+        os: [ubuntu-latest, windows-latest, macOS-latest]
+      fail-fast: false
+    runs-on: ${{ matrix.os }}
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v2
+    - name: Restore cache
+      uses: ./
+      with:
+        key: test-${{ runner.os }}-${{ github.run_id }}
+        path: |
+          test-cache
+          ~/test-cache
+    - name: Verify cache files in working directory
+      shell: bash
+      run: __tests__/verify-cache-files.sh ${{ runner.os }} test-cache
+    - name: Verify cache files outside working directory
+      shell: bash
+      run: __tests__/verify-cache-files.sh ${{ runner.os }} ~/test-cache
+
+  # End to end with proxy
+  test-proxy-save:
+    runs-on: ubuntu-latest
+    container:
+      image: ubuntu:latest
+      options: --dns 127.0.0.1
+    services:
+      squid-proxy:
+        image: datadog/squid:latest
+        ports:
+          - 3128:3128
+    env:
+      https_proxy: http://squid-proxy:3128
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v2
+    - name: Generate files
+      run: __tests__/create-cache-files.sh proxy test-cache
+    - name: Save cache
+      uses: ./
+      with:
+        key: test-proxy-${{ github.run_id }}
+        path: test-cache
+  test-proxy-restore:
+    needs: test-proxy-save
+    runs-on: ubuntu-latest
+    container:
+      image: ubuntu:latest
+      options: --dns 127.0.0.1
+    services:
+      squid-proxy:
+        image: datadog/squid:latest
+        ports:
+          - 3128:3128
+    env:
+      https_proxy: http://squid-proxy:3128
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v2
+    - name: Restore cache
+      uses: ./
+      with:
+        key: test-proxy-${{ github.run_id }}
+        path: test-cache
+    - name: Verify cache
+      run: __tests__/verify-cache-files.sh proxy test-cache

.gitignore

@@ -1,8 +1,5 @@
 __tests__/runner/*
 
-# comment out in distribution branches
-dist/
-
 node_modules/
 lib/
 
@@ -94,3 +91,6 @@ typings/
 
 # DynamoDB Local files
 .dynamodb/
+
+# Text editor files
+.vscode/

README.md

@@ -1,6 +1,6 @@
 # cache
 
-This GitHub Action allows caching dependencies and build outputs to improve workflow execution time.
+This action allows caching dependencies and build outputs to improve workflow execution time.
 
 <a href="https://github.com/actions/cache/actions?query=workflow%3ATests"><img alt="GitHub Actions status" src="https://github.com/actions/cache/workflows/Tests/badge.svg?branch=master&event=push"></a>
 
@@ -35,9 +35,9 @@ on: push
 jobs:
   build:
     runs-on: ubuntu-latest
-    
+
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
 
     - name: Cache Primes
       id: cache-primes
@@ -49,18 +49,40 @@ jobs:
     - name: Generate Prime Numbers
       if: steps.cache-primes.outputs.cache-hit != 'true'
       run: /generate-primes.sh -d prime-numbers
-    
+
     - name: Use Prime Numbers
       run: /primes.sh -d prime-numbers
 ```
 
-## Ecosystem Examples
+## Implementation Examples
 
-See [Examples](examples.md)
+Every programming language and framework has its own way of caching.
+
+See [Examples](examples.md) for a list of `actions/cache` implementations for use with:
+
+- [C# - Nuget](./examples.md#c---nuget)
+- [Elixir - Mix](./examples.md#elixir---mix)
+- [Go - Modules](./examples.md#go---modules)
+- [Haskell - Cabal](./examples.md#haskell---cabal)
+- [Java - Gradle](./examples.md#java---gradle)
+- [Java - Maven](./examples.md#java---maven)
+- [Node - npm](./examples.md#node---npm)
+- [Node - Lerna](./examples.md#node---lerna)
+- [Node - Yarn](./examples.md#node---yarn)
+- [OCaml/Reason - esy](./examples.md##ocamlreason---esy)
+- [PHP - Composer](./examples.md#php---composer)
+- [Python - pip](./examples.md#python---pip)
+- [R - renv](./examples.md#r---renv)
+- [Ruby - Bundler](./examples.md#ruby---bundler)
+- [Rust - Cargo](./examples.md#rust---cargo)
+- [Scala - SBT](./examples.md#scala---sbt)
+- [Swift, Objective-C - Carthage](./examples.md#swift-objective-c---carthage)
+- [Swift, Objective-C - CocoaPods](./examples.md#swift-objective-c---cocoapods)
+- [Swift - Swift Package Manager](./examples.md#swift---swift-package-manager)
 
 ## Cache Limits
 
-Individual caches are limited to 400MB and a repository can have up to 2GB of caches. Once the 2GB limit is reached, older caches will be evicted based on when the cache was last accessed.  Caches that are not accessed within the last week will also be evicted.
+A repository can have up to 5GB of caches. Once the 5GB limit is reached, older caches will be evicted based on when the cache was last accessed.  Caches that are not accessed within the last week will also be evicted.
 
 ## Skipping steps based on cache-hit
 
@@ -69,14 +91,14 @@ Using the `cache-hit` output, subsequent steps (such as install or build) can be
 Example:
 ```yaml
 steps:
-  - uses: actions/checkout@v1
+  - uses: actions/checkout@v2
 
   - uses: actions/cache@v1
     id: cache
     with:
       path: path/to/dependencies
       key: ${{ runner.os }}-${{ hashFiles('**/lockfiles') }}
-  
+
   - name: Install Dependencies
     if: steps.cache.outputs.cache-hit != 'true'
     run: /install.sh

__tests__/actionUtils.test.ts

@@ -1,4 +1,6 @@
 import * as core from "@actions/core";
+import * as io from "@actions/io";
+import { promises as fs } from "fs";
 import * as os from "os";
 import * as path from "path";
 
@@ -6,13 +8,24 @@ import { Events, Outputs, State } from "../src/constants";
 import { ArtifactCacheEntry } from "../src/contracts";
 import * as actionUtils from "../src/utils/actionUtils";
 
+import uuid = require("uuid");
+
 jest.mock("@actions/core");
 jest.mock("os");
 
+function getTempDir(): string {
+    return path.join(__dirname, "_temp", "actionUtils");
+}
+
 afterEach(() => {
     delete process.env[Events.Key];
 });
 
+afterAll(async () => {
+    delete process.env["GITHUB_WORKSPACE"];
+    await io.rmRF(getTempDir());
+});
+
 test("getArchiveFileSize returns file size", () => {
     const filePath = path.join(__dirname, "__fixtures__", "helloWorld.txt");
 
@@ -181,17 +194,43 @@ test("isValidEvent returns false for unknown event", () => {
     expect(isValidEvent).toBe(false);
 });
 
-test("resolvePath with no ~ in path", () => {
-    const filePath = ".cache/yarn";
+test("resolvePaths with no ~ in path", async () => {
+    const filePath = ".cache";
 
-    const resolvedPath = actionUtils.resolvePath(filePath);
+    // Create the following layout:
+    //   cwd
+    //   cwd/.cache
+    //   cwd/.cache/file.txt
 
-    const expectedPath = path.resolve(filePath);
-    expect(resolvedPath).toBe(expectedPath);
+    const root = path.join(getTempDir(), "no-tilde");
+    // tarball entries will be relative to workspace
+    process.env["GITHUB_WORKSPACE"] = root;
+
+    await fs.mkdir(root, { recursive: true });
+    const cache = path.join(root, ".cache");
+    await fs.mkdir(cache, { recursive: true });
+    await fs.writeFile(path.join(cache, "file.txt"), "cached");
+
+    const originalCwd = process.cwd();
+
+    try {
+        process.chdir(root);
+
+        const resolvedPath = await actionUtils.resolvePaths([filePath]);
+
+        const expectedPath = [filePath];
+        expect(resolvedPath).toStrictEqual(expectedPath);
+    } finally {
+        process.chdir(originalCwd);
+    }
 });
 
-test("resolvePath with ~ in path", () => {
-    const filePath = "~/.cache/yarn";
+test("resolvePaths with ~ in path", async () => {
+    const cacheDir = uuid();
+    const filePath = `~/${cacheDir}`;
+    // Create the following layout:
+    //   ~/uuid
+    //   ~/uuid/file.txt
 
     const homedir = jest.requireActual("os").homedir();
     const homedirMock = jest.spyOn(os, "homedir");
@@ -199,24 +238,93 @@ test("resolvePath with ~ in path", () => {
         return homedir;
     });
 
-    const resolvedPath = actionUtils.resolvePath(filePath);
+    const target = path.join(homedir, cacheDir);
+    await fs.mkdir(target, { recursive: true });
+    await fs.writeFile(path.join(target, "file.txt"), "cached");
 
-    const expectedPath = path.join(homedir, ".cache/yarn");
-    expect(resolvedPath).toBe(expectedPath);
+    const root = getTempDir();
+    process.env["GITHUB_WORKSPACE"] = root;
+
+    try {
+        const resolvedPath = await actionUtils.resolvePaths([filePath]);
+
+        const expectedPath = [path.relative(root, target)];
+        expect(resolvedPath).toStrictEqual(expectedPath);
+    } finally {
+        await io.rmRF(target);
+    }
 });
 
-test("resolvePath with home not found", () => {
+test("resolvePaths with home not found", async () => {
     const filePath = "~/.cache/yarn";
     const homedirMock = jest.spyOn(os, "homedir");
     homedirMock.mockImplementation(() => {
         return "";
     });
 
-    expect(() => actionUtils.resolvePath(filePath)).toThrow(
-        "Unable to resolve `~` to HOME"
+    await expect(actionUtils.resolvePaths([filePath])).rejects.toThrow(
+        "Unable to determine HOME directory"
     );
 });
 
+test("resolvePaths inclusion pattern returns found", async () => {
+    const pattern = "*.ts";
+    // Create the following layout:
+    //   inclusion-patterns
+    //   inclusion-patterns/miss.txt
+    //   inclusion-patterns/test.ts
+
+    const root = path.join(getTempDir(), "inclusion-patterns");
+    // tarball entries will be relative to workspace
+    process.env["GITHUB_WORKSPACE"] = root;
+
+    await fs.mkdir(root, { recursive: true });
+    await fs.writeFile(path.join(root, "miss.txt"), "no match");
+    await fs.writeFile(path.join(root, "test.ts"), "match");
+
+    const originalCwd = process.cwd();
+
+    try {
+        process.chdir(root);
+
+        const resolvedPath = await actionUtils.resolvePaths([pattern]);
+
+        const expectedPath = ["test.ts"];
+        expect(resolvedPath).toStrictEqual(expectedPath);
+    } finally {
+        process.chdir(originalCwd);
+    }
+});
+
+test("resolvePaths exclusion pattern returns not found", async () => {
+    const patterns = ["*.ts", "!test.ts"];
+    // Create the following layout:
+    //   exclusion-patterns
+    //   exclusion-patterns/miss.txt
+    //   exclusion-patterns/test.ts
+
+    const root = path.join(getTempDir(), "exclusion-patterns");
+    // tarball entries will be relative to workspace
+    process.env["GITHUB_WORKSPACE"] = root;
+
+    await fs.mkdir(root, { recursive: true });
+    await fs.writeFile(path.join(root, "miss.txt"), "no match");
+    await fs.writeFile(path.join(root, "test.ts"), "no match");
+
+    const originalCwd = process.cwd();
+
+    try {
+        process.chdir(root);
+
+        const resolvedPath = await actionUtils.resolvePaths(patterns);
+
+        const expectedPath = [];
+        expect(resolvedPath).toStrictEqual(expectedPath);
+    } finally {
+        process.chdir(originalCwd);
+    }
+});
+
 test("isValidEvent returns true for push event", () => {
     const event = Events.Push;
     process.env[Events.Key] = event;
@@ -234,3 +342,16 @@ test("isValidEvent returns true for pull request event", () => {
 
     expect(isValidEvent).toBe(true);
 });
+
+test("unlinkFile unlinks file", async () => {
+    const testDirectory = await fs.mkdtemp("unlinkFileTest");
+    const testFile = path.join(testDirectory, "test.txt");
+    await fs.writeFile(testFile, "hello world");
+
+    await actionUtils.unlinkFile(testFile);
+
+    // This should throw as testFile should not exist
+    await expect(fs.stat(testFile)).rejects.toThrow();
+
+    await fs.rmdir(testDirectory);
+});

__tests__/cacheHttpsClient.test.ts

@@ -0,0 +1,177 @@
+import { getCacheVersion, retry } from "../src/cacheHttpClient";
+import { CompressionMethod, Inputs } from "../src/constants";
+import * as testUtils from "../src/utils/testUtils";
+
+afterEach(() => {
+    testUtils.clearInputs();
+});
+
+test("getCacheVersion with path input and compression method undefined returns version", async () => {
+    testUtils.setInput(Inputs.Path, "node_modules");
+
+    const result = getCacheVersion();
+
+    expect(result).toEqual(
+        "b3e0c6cb5ecf32614eeb2997d905b9c297046d7cbf69062698f25b14b4cb0985"
+    );
+});
+
+test("getCacheVersion with zstd compression returns version", async () => {
+    testUtils.setInput(Inputs.Path, "node_modules");
+    const result = getCacheVersion(CompressionMethod.Zstd);
+
+    expect(result).toEqual(
+        "273877e14fd65d270b87a198edbfa2db5a43de567c9a548d2a2505b408befe24"
+    );
+});
+
+test("getCacheVersion with gzip compression does not change vesion", async () => {
+    testUtils.setInput(Inputs.Path, "node_modules");
+    const result = getCacheVersion(CompressionMethod.Gzip);
+
+    expect(result).toEqual(
+        "b3e0c6cb5ecf32614eeb2997d905b9c297046d7cbf69062698f25b14b4cb0985"
+    );
+});
+
+test("getCacheVersion with no input throws", async () => {
+    expect(() => getCacheVersion()).toThrow();
+});
+
+interface TestResponse {
+    statusCode: number;
+    result: string | null;
+}
+
+function handleResponse(
+    response: TestResponse | undefined
+): Promise<TestResponse> {
+    if (!response) {
+        fail("Retry method called too many times");
+    }
+
+    if (response.statusCode === 999) {
+        throw Error("Test Error");
+    } else {
+        return Promise.resolve(response);
+    }
+}
+
+async function testRetryExpectingResult(
+    responses: Array<TestResponse>,
+    expectedResult: string | null
+): Promise<void> {
+    responses = responses.reverse(); // Reverse responses since we pop from end
+
+    const actualResult = await retry(
+        "test",
+        () => handleResponse(responses.pop()),
+        (response: TestResponse) => response.statusCode
+    );
+
+    expect(actualResult.result).toEqual(expectedResult);
+}
+
+async function testRetryExpectingError(
+    responses: Array<TestResponse>
+): Promise<void> {
+    responses = responses.reverse(); // Reverse responses since we pop from end
+
+    expect(
+        retry(
+            "test",
+            () => handleResponse(responses.pop()),
+            (response: TestResponse) => response.statusCode
+        )
+    ).rejects.toBeInstanceOf(Error);
+}
+
+test("retry works on successful response", async () => {
+    await testRetryExpectingResult(
+        [
+            {
+                statusCode: 200,
+                result: "Ok"
+            }
+        ],
+        "Ok"
+    );
+});
+
+test("retry works after retryable status code", async () => {
+    await testRetryExpectingResult(
+        [
+            {
+                statusCode: 503,
+                result: null
+            },
+            {
+                statusCode: 200,
+                result: "Ok"
+            }
+        ],
+        "Ok"
+    );
+});
+
+test("retry fails after exhausting retries", async () => {
+    await testRetryExpectingError([
+        {
+            statusCode: 503,
+            result: null
+        },
+        {
+            statusCode: 503,
+            result: null
+        },
+        {
+            statusCode: 200,
+            result: "Ok"
+        }
+    ]);
+});
+
+test("retry fails after non-retryable status code", async () => {
+    await testRetryExpectingError([
+        {
+            statusCode: 500,
+            result: null
+        },
+        {
+            statusCode: 200,
+            result: "Ok"
+        }
+    ]);
+});
+
+test("retry works after error", async () => {
+    await testRetryExpectingResult(
+        [
+            {
+                statusCode: 999,
+                result: null
+            },
+            {
+                statusCode: 200,
+                result: "Ok"
+            }
+        ],
+        "Ok"
+    );
+});
+
+test("retry returns after client error", async () => {
+    await testRetryExpectingResult(
+        [
+            {
+                statusCode: 400,
+                result: null
+            },
+            {
+                statusCode: 200,
+                result: "Ok"
+            }
+        ],
+        null
+    );
+});

__tests__/create-cache-files.sh

@@ -0,0 +1,17 @@
+#!/bin/sh
+
+# Validate args
+prefix="$1"
+if [ -z "$prefix" ]; then
+  echo "Must supply prefix argument"
+  exit 1
+fi
+
+path="$2"
+if [ -z "$path" ]; then
+  echo "Must supply path argument"
+  exit 1
+fi
+
+mkdir -p $path
+echo "$prefix $GITHUB_RUN_ID" > $path/test-file.txt

__tests__/restore.test.ts

@@ -1,24 +1,24 @@
 import * as core from "@actions/core";
-import * as exec from "@actions/exec";
-import * as io from "@actions/io";
 import * as path from "path";
+
 import * as cacheHttpClient from "../src/cacheHttpClient";
-import { Events, Inputs } from "../src/constants";
+import {
+    CacheFilename,
+    CompressionMethod,
+    Events,
+    Inputs
+} from "../src/constants";
 import { ArtifactCacheEntry } from "../src/contracts";
 import run from "../src/restore";
+import * as tar from "../src/tar";
 import * as actionUtils from "../src/utils/actionUtils";
 import * as testUtils from "../src/utils/testUtils";
 
-jest.mock("@actions/exec");
-jest.mock("@actions/io");
-jest.mock("../src/utils/actionUtils");
 jest.mock("../src/cacheHttpClient");
+jest.mock("../src/tar");
+jest.mock("../src/utils/actionUtils");
 
 beforeAll(() => {
-    jest.spyOn(actionUtils, "resolvePath").mockImplementation(filePath => {
-        return path.resolve(filePath);
-    });
-
     jest.spyOn(actionUtils, "isExactKeyMatch").mockImplementation(
         (key, cacheResult) => {
             const actualUtils = jest.requireActual("../src/utils/actionUtils");
@@ -36,8 +36,9 @@ beforeAll(() => {
         return actualUtils.getSupportedEvents();
     });
 
-    jest.spyOn(io, "which").mockImplementation(tool => {
-        return Promise.resolve(tool);
+    jest.spyOn(actionUtils, "getCacheFileName").mockImplementation(cm => {
+        const actualUtils = jest.requireActual("../src/utils/actionUtils");
+        return actualUtils.getCacheFileName(cm);
     });
 });
 
@@ -65,7 +66,8 @@ test("restore with invalid event outputs warning", async () => {
 test("restore with no path should fail", async () => {
     const failedMock = jest.spyOn(core, "setFailed");
     await run();
-    expect(failedMock).toHaveBeenCalledWith(
+    // this input isn't necessary for restore b/c tarball contains entries relative to workspace
+    expect(failedMock).not.toHaveBeenCalledWith(
         "Input required and not supplied: path"
     );
 });
@@ -142,7 +144,7 @@ test("restore with no cache found", async () => {
     expect(failedMock).toHaveBeenCalledTimes(0);
 
     expect(infoMock).toHaveBeenCalledWith(
-        `Cache not found for input keys: ${key}.`
+        `Cache not found for input keys: ${key}`
     );
 });
 
@@ -201,13 +203,12 @@ test("restore with restore keys and no cache found", async () => {
     expect(failedMock).toHaveBeenCalledTimes(0);
 
     expect(infoMock).toHaveBeenCalledWith(
-        `Cache not found for input keys: ${key}, ${restoreKey}.`
+        `Cache not found for input keys: ${key}, ${restoreKey}`
     );
 });
 
-test("restore with cache found", async () => {
+test("restore with gzip compressed cache found", async () => {
     const key = "node-test";
-    const cachePath = path.resolve("node_modules");
     testUtils.setInputs({
         path: "node_modules",
         key
@@ -236,7 +237,7 @@ test("restore with cache found", async () => {
         return Promise.resolve(tempPath);
     });
 
-    const archivePath = path.join(tempPath, "cache.tgz");
+    const archivePath = path.join(tempPath, CacheFilename.Gzip);
     const setCacheStateMock = jest.spyOn(actionUtils, "setCacheState");
     const downloadCacheMock = jest.spyOn(cacheHttpClient, "downloadCache");
 
@@ -245,45 +246,45 @@ test("restore with cache found", async () => {
         .spyOn(actionUtils, "getArchiveFileSize")
         .mockReturnValue(fileSize);
 
-    const mkdirMock = jest.spyOn(io, "mkdirP");
-    const execMock = jest.spyOn(exec, "exec");
+    const extractTarMock = jest.spyOn(tar, "extractTar");
+    const unlinkFileMock = jest.spyOn(actionUtils, "unlinkFile");
     const setCacheHitOutputMock = jest.spyOn(actionUtils, "setCacheHitOutput");
 
+    const compression = CompressionMethod.Gzip;
+    const getCompressionMock = jest
+        .spyOn(actionUtils, "getCompressionMethod")
+        .mockReturnValue(Promise.resolve(compression));
+
     await run();
 
     expect(stateMock).toHaveBeenCalledWith("CACHE_KEY", key);
-    expect(getCacheMock).toHaveBeenCalledWith([key]);
+    expect(getCacheMock).toHaveBeenCalledWith([key], {
+        compressionMethod: compression
+    });
     expect(setCacheStateMock).toHaveBeenCalledWith(cacheEntry);
     expect(createTempDirectoryMock).toHaveBeenCalledTimes(1);
-    expect(downloadCacheMock).toHaveBeenCalledWith(cacheEntry, archivePath);
+    expect(downloadCacheMock).toHaveBeenCalledWith(
+        cacheEntry.archiveLocation,
+        archivePath
+    );
     expect(getArchiveFileSizeMock).toHaveBeenCalledWith(archivePath);
-    expect(mkdirMock).toHaveBeenCalledWith(cachePath);
 
-    const IS_WINDOWS = process.platform === "win32";
-    const args = IS_WINDOWS
-        ? [
-              "-xz",
-              "--force-local",
-              "-f",
-              archivePath.replace(/\\/g, "/"),
-              "-C",
-              cachePath.replace(/\\/g, "/")
-          ]
-        : ["-xz", "-f", archivePath, "-C", cachePath];
+    expect(extractTarMock).toHaveBeenCalledTimes(1);
+    expect(extractTarMock).toHaveBeenCalledWith(archivePath, compression);
 
-    expect(execMock).toHaveBeenCalledTimes(1);
-    expect(execMock).toHaveBeenCalledWith(`"tar"`, args);
+    expect(unlinkFileMock).toHaveBeenCalledTimes(1);
+    expect(unlinkFileMock).toHaveBeenCalledWith(archivePath);
 
     expect(setCacheHitOutputMock).toHaveBeenCalledTimes(1);
     expect(setCacheHitOutputMock).toHaveBeenCalledWith(true);
 
     expect(infoMock).toHaveBeenCalledWith(`Cache restored from key: ${key}`);
     expect(failedMock).toHaveBeenCalledTimes(0);
+    expect(getCompressionMock).toHaveBeenCalledTimes(1);
 });
 
-test("restore with a pull request event and cache found", async () => {
+test("restore with a pull request event and zstd compressed cache found", async () => {
     const key = "node-test";
-    const cachePath = path.resolve("node_modules");
     testUtils.setInputs({
         path: "node_modules",
         key
@@ -314,7 +315,7 @@ test("restore with a pull request event and cache found", async () => {
         return Promise.resolve(tempPath);
     });
 
-    const archivePath = path.join(tempPath, "cache.tgz");
+    const archivePath = path.join(tempPath, CacheFilename.Zstd);
     const setCacheStateMock = jest.spyOn(actionUtils, "setCacheState");
     const downloadCacheMock = jest.spyOn(cacheHttpClient, "downloadCache");
 
@@ -323,47 +324,42 @@ test("restore with a pull request event and cache found", async () => {
         .spyOn(actionUtils, "getArchiveFileSize")
         .mockReturnValue(fileSize);
 
-    const mkdirMock = jest.spyOn(io, "mkdirP");
-    const execMock = jest.spyOn(exec, "exec");
+    const extractTarMock = jest.spyOn(tar, "extractTar");
     const setCacheHitOutputMock = jest.spyOn(actionUtils, "setCacheHitOutput");
+    const compression = CompressionMethod.Zstd;
+    const getCompressionMock = jest
+        .spyOn(actionUtils, "getCompressionMethod")
+        .mockReturnValue(Promise.resolve(compression));
 
     await run();
 
     expect(stateMock).toHaveBeenCalledWith("CACHE_KEY", key);
-    expect(getCacheMock).toHaveBeenCalledWith([key]);
+    expect(getCacheMock).toHaveBeenCalledWith([key], {
+        compressionMethod: compression
+    });
     expect(setCacheStateMock).toHaveBeenCalledWith(cacheEntry);
     expect(createTempDirectoryMock).toHaveBeenCalledTimes(1);
-    expect(downloadCacheMock).toHaveBeenCalledWith(cacheEntry, archivePath);
+    expect(downloadCacheMock).toHaveBeenCalledWith(
+        cacheEntry.archiveLocation,
+        archivePath
+    );
     expect(getArchiveFileSizeMock).toHaveBeenCalledWith(archivePath);
     expect(infoMock).toHaveBeenCalledWith(`Cache Size: ~60 MB (62915000 B)`);
-    expect(mkdirMock).toHaveBeenCalledWith(cachePath);
 
-    const IS_WINDOWS = process.platform === "win32";
-    const args = IS_WINDOWS
-        ? [
-              "-xz",
-              "--force-local",
-              "-f",
-              archivePath.replace(/\\/g, "/"),
-              "-C",
-              cachePath.replace(/\\/g, "/")
-          ]
-        : ["-xz", "-f", archivePath, "-C", cachePath];
-
-    expect(execMock).toHaveBeenCalledTimes(1);
-    expect(execMock).toHaveBeenCalledWith(`"tar"`, args);
+    expect(extractTarMock).toHaveBeenCalledTimes(1);
+    expect(extractTarMock).toHaveBeenCalledWith(archivePath, compression);
 
     expect(setCacheHitOutputMock).toHaveBeenCalledTimes(1);
     expect(setCacheHitOutputMock).toHaveBeenCalledWith(true);
 
     expect(infoMock).toHaveBeenCalledWith(`Cache restored from key: ${key}`);
     expect(failedMock).toHaveBeenCalledTimes(0);
+    expect(getCompressionMock).toHaveBeenCalledTimes(1);
 });
 
 test("restore with cache found for restore key", async () => {
     const key = "node-test";
     const restoreKey = "node-";
-    const cachePath = path.resolve("node_modules");
     testUtils.setInputs({
         path: "node_modules",
         key,
@@ -393,7 +389,7 @@ test("restore with cache found for restore key", async () => {
         return Promise.resolve(tempPath);
     });
 
-    const archivePath = path.join(tempPath, "cache.tgz");
+    const archivePath = path.join(tempPath, CacheFilename.Zstd);
     const setCacheStateMock = jest.spyOn(actionUtils, "setCacheState");
     const downloadCacheMock = jest.spyOn(cacheHttpClient, "downloadCache");
 
@@ -402,35 +398,30 @@ test("restore with cache found for restore key", async () => {
         .spyOn(actionUtils, "getArchiveFileSize")
         .mockReturnValue(fileSize);
 
-    const mkdirMock = jest.spyOn(io, "mkdirP");
-    const execMock = jest.spyOn(exec, "exec");
+    const extractTarMock = jest.spyOn(tar, "extractTar");
     const setCacheHitOutputMock = jest.spyOn(actionUtils, "setCacheHitOutput");
+    const compression = CompressionMethod.Zstd;
+    const getCompressionMock = jest
+        .spyOn(actionUtils, "getCompressionMethod")
+        .mockReturnValue(Promise.resolve(compression));
 
     await run();
 
     expect(stateMock).toHaveBeenCalledWith("CACHE_KEY", key);
-    expect(getCacheMock).toHaveBeenCalledWith([key, restoreKey]);
+    expect(getCacheMock).toHaveBeenCalledWith([key, restoreKey], {
+        compressionMethod: compression
+    });
     expect(setCacheStateMock).toHaveBeenCalledWith(cacheEntry);
     expect(createTempDirectoryMock).toHaveBeenCalledTimes(1);
-    expect(downloadCacheMock).toHaveBeenCalledWith(cacheEntry, archivePath);
+    expect(downloadCacheMock).toHaveBeenCalledWith(
+        cacheEntry.archiveLocation,
+        archivePath
+    );
     expect(getArchiveFileSizeMock).toHaveBeenCalledWith(archivePath);
     expect(infoMock).toHaveBeenCalledWith(`Cache Size: ~0 MB (142 B)`);
-    expect(mkdirMock).toHaveBeenCalledWith(cachePath);
 
-    const IS_WINDOWS = process.platform === "win32";
-    const args = IS_WINDOWS
-        ? [
-              "-xz",
-              "--force-local",
-              "-f",
-              archivePath.replace(/\\/g, "/"),
-              "-C",
-              cachePath.replace(/\\/g, "/")
-          ]
-        : ["-xz", "-f", archivePath, "-C", cachePath];
-
-    expect(execMock).toHaveBeenCalledTimes(1);
-    expect(execMock).toHaveBeenCalledWith(`"tar"`, args);
+    expect(extractTarMock).toHaveBeenCalledTimes(1);
+    expect(extractTarMock).toHaveBeenCalledWith(archivePath, compression);
 
     expect(setCacheHitOutputMock).toHaveBeenCalledTimes(1);
     expect(setCacheHitOutputMock).toHaveBeenCalledWith(false);
@@ -439,4 +430,5 @@ test("restore with cache found for restore key", async () => {
         `Cache restored from key: ${restoreKey}`
     );
     expect(failedMock).toHaveBeenCalledTimes(0);
+    expect(getCompressionMock).toHaveBeenCalledTimes(1);
 });

__tests__/save.test.ts

@@ -1,19 +1,23 @@
 import * as core from "@actions/core";
-import * as exec from "@actions/exec";
-import * as io from "@actions/io";
 import * as path from "path";
+
 import * as cacheHttpClient from "../src/cacheHttpClient";
-import { Events, Inputs } from "../src/constants";
+import {
+    CacheFilename,
+    CompressionMethod,
+    Events,
+    Inputs
+} from "../src/constants";
 import { ArtifactCacheEntry } from "../src/contracts";
 import run from "../src/save";
+import * as tar from "../src/tar";
 import * as actionUtils from "../src/utils/actionUtils";
 import * as testUtils from "../src/utils/testUtils";
 
 jest.mock("@actions/core");
-jest.mock("@actions/exec");
-jest.mock("@actions/io");
-jest.mock("../src/utils/actionUtils");
 jest.mock("../src/cacheHttpClient");
+jest.mock("../src/tar");
+jest.mock("../src/utils/actionUtils");
 
 beforeAll(() => {
     jest.spyOn(core, "getInput").mockImplementation((name, options) => {
@@ -42,16 +46,19 @@ beforeAll(() => {
         return actualUtils.getSupportedEvents();
     });
 
-    jest.spyOn(actionUtils, "resolvePath").mockImplementation(filePath => {
-        return path.resolve(filePath);
-    });
+    jest.spyOn(actionUtils, "resolvePaths").mockImplementation(
+        async filePaths => {
+            return filePaths.map(x => path.resolve(x));
+        }
+    );
 
     jest.spyOn(actionUtils, "createTempDirectory").mockImplementation(() => {
         return Promise.resolve("/foo/bar");
     });
 
-    jest.spyOn(io, "which").mockImplementation(tool => {
-        return Promise.resolve(tool);
+    jest.spyOn(actionUtils, "getCacheFileName").mockImplementation(cm => {
+        const actualUtils = jest.requireActual("../src/utils/actionUtils");
+        return actualUtils.getCacheFileName(cm);
     });
 });
 
@@ -128,7 +135,7 @@ test("save with exact match returns early", async () => {
             return primaryKey;
         });
 
-    const execMock = jest.spyOn(exec, "exec");
+    const createTarMock = jest.spyOn(tar, "createTar");
 
     await run();
 
@@ -136,7 +143,7 @@ test("save with exact match returns early", async () => {
         `Cache hit occurred on the primary key ${primaryKey}, not saving cache.`
     );
 
-    expect(execMock).toHaveBeenCalledTimes(0);
+    expect(createTarMock).toHaveBeenCalledTimes(0);
 
     expect(failedMock).toHaveBeenCalledTimes(0);
 });
@@ -195,42 +202,93 @@ test("save with large cache outputs warning", async () => {
         });
 
     const inputPath = "node_modules";
-    const cachePath = path.resolve(inputPath);
+    const cachePaths = [path.resolve(inputPath)];
     testUtils.setInput(Inputs.Path, inputPath);
 
-    const execMock = jest.spyOn(exec, "exec");
+    const createTarMock = jest.spyOn(tar, "createTar");
 
-    const cacheSize = 1024 * 1024 * 1024; //~1GB, over the 400MB limit
+    const cacheSize = 6 * 1024 * 1024 * 1024; //~6GB, over the 5GB limit
     jest.spyOn(actionUtils, "getArchiveFileSize").mockImplementationOnce(() => {
         return cacheSize;
     });
+    const compression = CompressionMethod.Gzip;
+    const getCompressionMock = jest
+        .spyOn(actionUtils, "getCompressionMethod")
+        .mockReturnValue(Promise.resolve(compression));
 
     await run();
 
-    const archivePath = path.join("/foo/bar", "cache.tgz");
-
-    const IS_WINDOWS = process.platform === "win32";
-    const args = IS_WINDOWS
-        ? [
-              "-cz",
-              "--force-local",
-              "-f",
-              archivePath.replace(/\\/g, "/"),
-              "-C",
-              cachePath.replace(/\\/g, "/"),
-              "."
-          ]
-        : ["-cz", "-f", archivePath, "-C", cachePath, "."];
-
-    expect(execMock).toHaveBeenCalledTimes(1);
-    expect(execMock).toHaveBeenCalledWith(`"tar"`, args);
+    const archiveFolder = "/foo/bar";
 
+    expect(createTarMock).toHaveBeenCalledTimes(1);
+    expect(createTarMock).toHaveBeenCalledWith(
+        archiveFolder,
+        cachePaths,
+        compression
+    );
     expect(logWarningMock).toHaveBeenCalledTimes(1);
     expect(logWarningMock).toHaveBeenCalledWith(
-        "Cache size of ~1024 MB (1073741824 B) is over the 400MB limit, not saving cache."
+        "Cache size of ~6144 MB (6442450944 B) is over the 5GB limit, not saving cache."
+    );
+    expect(failedMock).toHaveBeenCalledTimes(0);
+    expect(getCompressionMock).toHaveBeenCalledTimes(1);
+});
+
+test("save with reserve cache failure outputs warning", async () => {
+    const infoMock = jest.spyOn(core, "info");
+    const logWarningMock = jest.spyOn(actionUtils, "logWarning");
+    const failedMock = jest.spyOn(core, "setFailed");
+
+    const primaryKey = "Linux-node-bb828da54c148048dd17899ba9fda624811cfb43";
+    const cacheEntry: ArtifactCacheEntry = {
+        cacheKey: "Linux-node-",
+        scope: "refs/heads/master",
+        creationTime: "2019-11-13T19:18:02+00:00",
+        archiveLocation: "www.actionscache.test/download"
+    };
+
+    jest.spyOn(core, "getState")
+        // Cache Entry State
+        .mockImplementationOnce(() => {
+            return JSON.stringify(cacheEntry);
+        })
+        // Cache Key State
+        .mockImplementationOnce(() => {
+            return primaryKey;
+        });
+
+    const inputPath = "node_modules";
+    testUtils.setInput(Inputs.Path, inputPath);
+
+    const reserveCacheMock = jest
+        .spyOn(cacheHttpClient, "reserveCache")
+        .mockImplementationOnce(() => {
+            return Promise.resolve(-1);
+        });
+
+    const createTarMock = jest.spyOn(tar, "createTar");
+    const saveCacheMock = jest.spyOn(cacheHttpClient, "saveCache");
+    const compression = CompressionMethod.Zstd;
+    const getCompressionMock = jest
+        .spyOn(actionUtils, "getCompressionMethod")
+        .mockReturnValue(Promise.resolve(compression));
+
+    await run();
+
+    expect(reserveCacheMock).toHaveBeenCalledTimes(1);
+    expect(reserveCacheMock).toHaveBeenCalledWith(primaryKey, {
+        compressionMethod: compression
+    });
+
+    expect(infoMock).toHaveBeenCalledWith(
+        `Unable to reserve cache with key ${primaryKey}, another job may be creating this cache.`
     );
 
+    expect(createTarMock).toHaveBeenCalledTimes(0);
+    expect(saveCacheMock).toHaveBeenCalledTimes(0);
+    expect(logWarningMock).toHaveBeenCalledTimes(0);
     expect(failedMock).toHaveBeenCalledTimes(0);
+    expect(getCompressionMock).toHaveBeenCalledTimes(1);
 });
 
 test("save with server error outputs warning", async () => {
@@ -256,44 +314,53 @@ test("save with server error outputs warning", async () => {
         });
 
     const inputPath = "node_modules";
-    const cachePath = path.resolve(inputPath);
+    const cachePaths = [path.resolve(inputPath)];
     testUtils.setInput(Inputs.Path, inputPath);
 
-    const execMock = jest.spyOn(exec, "exec");
+    const cacheId = 4;
+    const reserveCacheMock = jest
+        .spyOn(cacheHttpClient, "reserveCache")
+        .mockImplementationOnce(() => {
+            return Promise.resolve(cacheId);
+        });
+
+    const createTarMock = jest.spyOn(tar, "createTar");
 
     const saveCacheMock = jest
         .spyOn(cacheHttpClient, "saveCache")
         .mockImplementationOnce(() => {
             throw new Error("HTTP Error Occurred");
         });
+    const compression = CompressionMethod.Zstd;
+    const getCompressionMock = jest
+        .spyOn(actionUtils, "getCompressionMethod")
+        .mockReturnValue(Promise.resolve(compression));
 
     await run();
 
-    const archivePath = path.join("/foo/bar", "cache.tgz");
+    expect(reserveCacheMock).toHaveBeenCalledTimes(1);
+    expect(reserveCacheMock).toHaveBeenCalledWith(primaryKey, {
+        compressionMethod: compression
+    });
 
-    const IS_WINDOWS = process.platform === "win32";
-    const args = IS_WINDOWS
-        ? [
-              "-cz",
-              "--force-local",
-              "-f",
-              archivePath.replace(/\\/g, "/"),
-              "-C",
-              cachePath.replace(/\\/g, "/"),
-              "."
-          ]
-        : ["-cz", "-f", archivePath, "-C", cachePath, "."];
+    const archiveFolder = "/foo/bar";
+    const archiveFile = path.join(archiveFolder, CacheFilename.Zstd);
 
-    expect(execMock).toHaveBeenCalledTimes(1);
-    expect(execMock).toHaveBeenCalledWith(`"tar"`, args);
+    expect(createTarMock).toHaveBeenCalledTimes(1);
+    expect(createTarMock).toHaveBeenCalledWith(
+        archiveFolder,
+        cachePaths,
+        compression
+    );
 
     expect(saveCacheMock).toHaveBeenCalledTimes(1);
-    expect(saveCacheMock).toHaveBeenCalledWith(primaryKey, archivePath);
+    expect(saveCacheMock).toHaveBeenCalledWith(cacheId, archiveFile);
 
     expect(logWarningMock).toHaveBeenCalledTimes(1);
     expect(logWarningMock).toHaveBeenCalledWith("HTTP Error Occurred");
 
     expect(failedMock).toHaveBeenCalledTimes(0);
+    expect(getCompressionMock).toHaveBeenCalledTimes(1);
 });
 
 test("save with valid inputs uploads a cache", async () => {
@@ -318,35 +385,44 @@ test("save with valid inputs uploads a cache", async () => {
         });
 
     const inputPath = "node_modules";
-    const cachePath = path.resolve(inputPath);
+    const cachePaths = [path.resolve(inputPath)];
     testUtils.setInput(Inputs.Path, inputPath);
 
-    const execMock = jest.spyOn(exec, "exec");
+    const cacheId = 4;
+    const reserveCacheMock = jest
+        .spyOn(cacheHttpClient, "reserveCache")
+        .mockImplementationOnce(() => {
+            return Promise.resolve(cacheId);
+        });
+
+    const createTarMock = jest.spyOn(tar, "createTar");
 
     const saveCacheMock = jest.spyOn(cacheHttpClient, "saveCache");
+    const compression = CompressionMethod.Zstd;
+    const getCompressionMock = jest
+        .spyOn(actionUtils, "getCompressionMethod")
+        .mockReturnValue(Promise.resolve(compression));
 
     await run();
 
-    const archivePath = path.join("/foo/bar", "cache.tgz");
+    expect(reserveCacheMock).toHaveBeenCalledTimes(1);
+    expect(reserveCacheMock).toHaveBeenCalledWith(primaryKey, {
+        compressionMethod: compression
+    });
 
-    const IS_WINDOWS = process.platform === "win32";
-    const args = IS_WINDOWS
-        ? [
-              "-cz",
-              "--force-local",
-              "-f",
-              archivePath.replace(/\\/g, "/"),
-              "-C",
-              cachePath.replace(/\\/g, "/"),
-              "."
-          ]
-        : ["-cz", "-f", archivePath, "-C", cachePath, "."];
+    const archiveFolder = "/foo/bar";
+    const archiveFile = path.join(archiveFolder, CacheFilename.Zstd);
 
-    expect(execMock).toHaveBeenCalledTimes(1);
-    expect(execMock).toHaveBeenCalledWith(`"tar"`, args);
+    expect(createTarMock).toHaveBeenCalledTimes(1);
+    expect(createTarMock).toHaveBeenCalledWith(
+        archiveFolder,
+        cachePaths,
+        compression
+    );
 
     expect(saveCacheMock).toHaveBeenCalledTimes(1);
-    expect(saveCacheMock).toHaveBeenCalledWith(primaryKey, archivePath);
+    expect(saveCacheMock).toHaveBeenCalledWith(cacheId, archiveFile);
 
     expect(failedMock).toHaveBeenCalledTimes(0);
+    expect(getCompressionMock).toHaveBeenCalledTimes(1);
 });

__tests__/tar.test.ts

@@ -0,0 +1,204 @@
+import * as exec from "@actions/exec";
+import * as io from "@actions/io";
+import * as path from "path";
+
+import { CacheFilename, CompressionMethod } from "../src/constants";
+import * as tar from "../src/tar";
+import * as utils from "../src/utils/actionUtils";
+
+import fs = require("fs");
+
+jest.mock("@actions/exec");
+jest.mock("@actions/io");
+
+const IS_WINDOWS = process.platform === "win32";
+
+function getTempDir(): string {
+    return path.join(__dirname, "_temp", "tar");
+}
+
+beforeAll(async () => {
+    jest.spyOn(io, "which").mockImplementation(tool => {
+        return Promise.resolve(tool);
+    });
+
+    process.env["GITHUB_WORKSPACE"] = process.cwd();
+    await jest.requireActual("@actions/io").rmRF(getTempDir());
+});
+
+afterAll(async () => {
+    delete process.env["GITHUB_WORKSPACE"];
+    await jest.requireActual("@actions/io").rmRF(getTempDir());
+});
+
+test("zstd extract tar", async () => {
+    const mkdirMock = jest.spyOn(io, "mkdirP");
+    const execMock = jest.spyOn(exec, "exec");
+
+    const archivePath = IS_WINDOWS
+        ? `${process.env["windir"]}\\fakepath\\cache.tar`
+        : "cache.tar";
+    const workspace = process.env["GITHUB_WORKSPACE"];
+
+    await tar.extractTar(archivePath, CompressionMethod.Zstd);
+
+    expect(mkdirMock).toHaveBeenCalledWith(workspace);
+    const tarPath = IS_WINDOWS
+        ? `${process.env["windir"]}\\System32\\tar.exe`
+        : "tar";
+    expect(execMock).toHaveBeenCalledTimes(1);
+    expect(execMock).toHaveBeenCalledWith(
+        `"${tarPath}"`,
+        [
+            "--use-compress-program",
+            "zstd -d --long=30",
+            "-xf",
+            IS_WINDOWS ? archivePath.replace(/\\/g, "/") : archivePath,
+            "-P",
+            "-C",
+            IS_WINDOWS ? workspace?.replace(/\\/g, "/") : workspace
+        ],
+        { cwd: undefined }
+    );
+});
+
+test("gzip extract tar", async () => {
+    const mkdirMock = jest.spyOn(io, "mkdirP");
+    const execMock = jest.spyOn(exec, "exec");
+    const archivePath = IS_WINDOWS
+        ? `${process.env["windir"]}\\fakepath\\cache.tar`
+        : "cache.tar";
+    const workspace = process.env["GITHUB_WORKSPACE"];
+
+    await tar.extractTar(archivePath, CompressionMethod.Gzip);
+
+    expect(mkdirMock).toHaveBeenCalledWith(workspace);
+    const tarPath = IS_WINDOWS
+        ? `${process.env["windir"]}\\System32\\tar.exe`
+        : "tar";
+    expect(execMock).toHaveBeenCalledTimes(1);
+    expect(execMock).toHaveBeenCalledWith(
+        `"${tarPath}"`,
+        [
+            "-z",
+            "-xf",
+            IS_WINDOWS ? archivePath.replace(/\\/g, "/") : archivePath,
+            "-P",
+            "-C",
+            IS_WINDOWS ? workspace?.replace(/\\/g, "/") : workspace
+        ],
+        { cwd: undefined }
+    );
+});
+
+test("gzip extract GNU tar on windows", async () => {
+    if (IS_WINDOWS) {
+        jest.spyOn(fs, "existsSync").mockReturnValueOnce(false);
+
+        const isGnuMock = jest
+            .spyOn(utils, "useGnuTar")
+            .mockReturnValue(Promise.resolve(true));
+        const execMock = jest.spyOn(exec, "exec");
+        const archivePath = `${process.env["windir"]}\\fakepath\\cache.tar`;
+        const workspace = process.env["GITHUB_WORKSPACE"];
+
+        await tar.extractTar(archivePath, CompressionMethod.Gzip);
+
+        expect(isGnuMock).toHaveBeenCalledTimes(1);
+        expect(execMock).toHaveBeenCalledTimes(1);
+        expect(execMock).toHaveBeenCalledWith(
+            `"tar"`,
+            [
+                "-z",
+                "-xf",
+                archivePath.replace(/\\/g, "/"),
+                "-P",
+                "-C",
+                workspace?.replace(/\\/g, "/"),
+                "--force-local"
+            ],
+            { cwd: undefined }
+        );
+    }
+});
+
+test("zstd create tar", async () => {
+    const execMock = jest.spyOn(exec, "exec");
+
+    const archiveFolder = getTempDir();
+    const workspace = process.env["GITHUB_WORKSPACE"];
+    const sourceDirectories = ["~/.npm/cache", `${workspace}/dist`];
+
+    await fs.promises.mkdir(archiveFolder, { recursive: true });
+
+    await tar.createTar(
+        archiveFolder,
+        sourceDirectories,
+        CompressionMethod.Zstd
+    );
+
+    const tarPath = IS_WINDOWS
+        ? `${process.env["windir"]}\\System32\\tar.exe`
+        : "tar";
+
+    expect(execMock).toHaveBeenCalledTimes(1);
+    expect(execMock).toHaveBeenCalledWith(
+        `"${tarPath}"`,
+        [
+            "--use-compress-program",
+            "zstd -T0 --long=30",
+            "-cf",
+            IS_WINDOWS
+                ? CacheFilename.Zstd.replace(/\\/g, "/")
+                : CacheFilename.Zstd,
+            "-P",
+            "-C",
+            IS_WINDOWS ? workspace?.replace(/\\/g, "/") : workspace,
+            "--files-from",
+            "manifest.txt"
+        ],
+        {
+            cwd: archiveFolder
+        }
+    );
+});
+
+test("gzip create tar", async () => {
+    const execMock = jest.spyOn(exec, "exec");
+
+    const archiveFolder = getTempDir();
+    const workspace = process.env["GITHUB_WORKSPACE"];
+    const sourceDirectories = ["~/.npm/cache", `${workspace}/dist`];
+
+    await fs.promises.mkdir(archiveFolder, { recursive: true });
+
+    await tar.createTar(
+        archiveFolder,
+        sourceDirectories,
+        CompressionMethod.Gzip
+    );
+
+    const tarPath = IS_WINDOWS
+        ? `${process.env["windir"]}\\System32\\tar.exe`
+        : "tar";
+
+    expect(execMock).toHaveBeenCalledTimes(1);
+    expect(execMock).toHaveBeenCalledWith(
+        `"${tarPath}"`,
+        [
+            "-z",
+            "-cf",
+            IS_WINDOWS
+                ? CacheFilename.Gzip.replace(/\\/g, "/")
+                : CacheFilename.Gzip,
+            "-P",
+            "-C",
+            IS_WINDOWS ? workspace?.replace(/\\/g, "/") : workspace,
+            "--files-from",
+            "manifest.txt"
+        ],
+        {
+            cwd: archiveFolder
+        }
+    );
+});

__tests__/verify-cache-files.sh

@@ -0,0 +1,36 @@
+#!/bin/sh
+
+# Validate args
+prefix="$1"
+if [ -z "$prefix" ]; then
+  echo "Must supply prefix argument"
+  exit 1
+fi
+
+path="$2"
+if [ -z "$path" ]; then
+  echo "Must specify path argument"
+  exit 1
+fi
+
+# Sanity check GITHUB_RUN_ID defined
+if [ -z "$GITHUB_RUN_ID" ]; then
+  echo "GITHUB_RUN_ID not defined"
+  exit 1
+fi
+
+# Verify file exists
+file="$path/test-file.txt"
+echo "Checking for $file"
+if [ ! -e $file ]; then
+  echo "File does not exist"
+  exit 1
+fi
+
+# Verify file content
+content="$(cat $file)"
+echo "File content:\n$content"
+if [ -z "$(echo $content | grep --fixed-strings "$prefix $GITHUB_RUN_ID")" ]; then
+  echo "Unexpected file content"
+  exit 1
+fi

action.yml

@@ -1,5 +1,5 @@
 name: 'Cache'
-description: 'Cache dependencies and build outputs to improve workflow execution time'
+description: 'Cache artifacts like dependencies and build outputs to improve workflow execution time'
 author: 'GitHub'
 inputs:
   path:
@@ -21,4 +21,4 @@ runs:
   post-if: 'success()'
 branding:
   icon: 'archive'
-  color: 'gray-dark'
+  color: 'gray-dark'

examples.md

@@ -1,27 +1,36 @@
 # Examples
 
 - [Examples](#examples)
-  - [C# - Nuget](#c---nuget)
+  - [C# - NuGet](#c---nuget)
   - [Elixir - Mix](#elixir---mix)
   - [Go - Modules](#go---modules)
+  - [Haskell - Cabal](#haskell---cabal)
   - [Java - Gradle](#java---gradle)
   - [Java - Maven](#java---maven)
   - [Node - npm](#node---npm)
     - [macOS and Ubuntu](#macos-and-ubuntu)
     - [Windows](#windows)
     - [Using multiple systems and `npm config`](#using-multiple-systems-and-npm-config)
+  - [Node - Lerna](#node---lerna)
   - [Node - Yarn](#node---yarn)
+  - [OCaml/Reason - esy](#ocamlreason---esy)
   - [PHP - Composer](#php---composer)
   - [Python - pip](#python---pip)
     - [Simple example](#simple-example)
     - [Multiple OS's in a workflow](#multiple-oss-in-a-workflow)
+    - [Using pip to get cache location](#using-pip-to-get-cache-location)
     - [Using a script to get cache location](#using-a-script-to-get-cache-location)
-  - [Ruby - Gem](#ruby---gem)
+  - [R - renv](#r---renv)
+    - [Simple example](#simple-example-1)
+    - [Multiple OS's in a workflow](#multiple-oss-in-a-workflow-1)
+  - [Ruby - Bundler](#ruby---bundler)
   - [Rust - Cargo](#rust---cargo)
+  - [Scala - SBT](#scala---sbt)
   - [Swift, Objective-C - Carthage](#swift-objective-c---carthage)
   - [Swift, Objective-C - CocoaPods](#swift-objective-c---cocoapods)
+  - [Swift - Swift Package Manager](#swift---swift-package-manager)
 
-## C# - Nuget
+## C# - NuGet
 Using [NuGet lock files](https://docs.microsoft.com/nuget/consume-packages/package-references-in-project-files#locking-dependencies):
 
 ```yaml
@@ -33,6 +42,21 @@ Using [NuGet lock files](https://docs.microsoft.com/nuget/consume-packages/packa
       ${{ runner.os }}-nuget-
 ```
 
+Depending on the environment, huge packages might be pre-installed in the global cache folder.
+If you do not want to include them, consider to move the cache folder like below.
+>Note: This workflow does not work for projects that require files to be placed in user profile package folder
+```yaml
+env:
+  NUGET_PACKAGES: ${{ github.workspace }}/.nuget/packages
+steps:
+  - uses: actions/cache@v1
+    with:
+      path: ${{ github.workspace }}/.nuget/packages
+      key: ${{ runner.os }}-nuget-${{ hashFiles('**/packages.lock.json') }}
+      restore-keys: |
+        ${{ runner.os }}-nuget-
+```
+
 ## Elixir - Mix
 ```yaml
 - uses: actions/cache@v1
@@ -54,13 +78,35 @@ Using [NuGet lock files](https://docs.microsoft.com/nuget/consume-packages/packa
       ${{ runner.os }}-go-
 ```
 
+## Haskell - Cabal
+
+We cache the elements of the Cabal store separately, as the entirety of `~/.cabal` can grow very large for projects with many dependencies.
+
+```yaml
+- uses: actions/cache@v1
+  name: Cache ~/.cabal/packages
+  with:
+    path: ~/.cabal/packages
+    key: ${{ runner.os }}-${{ matrix.ghc }}-cabal-packages
+- uses: actions/cache@v1
+  name: Cache ~/.cabal/store
+  with:
+    path: ~/.cabal/store
+    key: ${{ runner.os }}-${{ matrix.ghc }}-cabal-store
+- uses: actions/cache@v1
+  name: Cache dist-newstyle
+  with:
+    path: dist-newstyle
+    key: ${{ runner.os }}-${{ matrix.ghc }}-dist-newstyle
+```
+
 ## Java - Gradle
 
 ```yaml
 - uses: actions/cache@v1
   with:
     path: ~/.gradle/caches
-    key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle') }}
+    key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle*') }}
     restore-keys: |
       ${{ runner.os }}-gradle-
 ```
@@ -96,17 +142,6 @@ For npm, cache files are stored in `~/.npm` on Posix, or `%AppData%/npm-cache` o
 ### Windows
 
 ```yaml
-- uses: actions/cache@v1
-  with:
-    path: ~\AppData\Roaming\npm-cache
-    key: ${{ runner.os }}-node-${{ hashFiles('**\package-lock.json') }}
-    restore-keys: |
-      ${{ runner.os }}-node-
-```
-
-### Using multiple systems and `npm config`
-
-```yaml  
 - name: Get npm cache directory
   id: npm-cache
   run: |
@@ -119,25 +154,82 @@ For npm, cache files are stored in `~/.npm` on Posix, or `%AppData%/npm-cache` o
       ${{ runner.os }}-node-
 ```
 
+### Using multiple systems and `npm config`
+
+```yaml
+- name: Get npm cache directory
+  id: npm-cache
+  run: |
+    echo "::set-output name=dir::$(npm config get cache)"
+- uses: actions/cache@v1
+  with:
+    path: ${{ steps.npm-cache.outputs.dir }}
+    key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}
+    restore-keys: |
+      ${{ runner.os }}-node-
+```
+
+## Node - Lerna
+
+>Note this example uses the new multi-paths feature and is only available at `master`
+```yaml
+- name: restore lerna
+  uses: actions/cache@master
+  with:
+    path: |
+      node_modules
+      */*/node_modules
+    key: ${{ runner.os }}-${{ hashFiles('**/yarn.lock') }}
+```
+
 ## Node - Yarn
 The yarn cache directory will depend on your operating system and version of `yarn`. See https://yarnpkg.com/lang/en/docs/cli/cache/ for more info.
 
 ```yaml
-- name: Get yarn cache
-  id: yarn-cache
+- name: Get yarn cache directory path
+  id: yarn-cache-dir-path
   run: echo "::set-output name=dir::$(yarn cache dir)"
 
 - uses: actions/cache@v1
+  id: yarn-cache # use this to check for `cache-hit` (`steps.yarn-cache.outputs.cache-hit != 'true'`)
   with:
-    path: ${{ steps.yarn-cache.outputs.dir }}
+    path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
     key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
     restore-keys: |
       ${{ runner.os }}-yarn-
 ```
 
+## OCaml/Reason - esy
+Esy allows you to export built dependencies and import pre-built dependencies.
+```yaml
+    - name: Restore Cache
+      id: restore-cache
+      uses: actions/cache@v1
+      with:
+        path: _export
+        key:  ${{ runner.os }}-esy-${{ hashFiles('esy.lock/index.json') }}
+        restore-keys: |
+          ${{ runner.os }}-esy-
+    - name: Esy install
+      run: 'esy install'
+    - name: Import Cache
+      run: |
+        esy import-dependencies _export
+        rm -rf _export
+
+    ...(Build job)...
+
+    # Re-export dependencies if anything has changed or if it is the first time
+    - name: Setting dependency cache 
+      run: |
+        esy export-dependencies
+      if: steps.restore-cache.outputs.cache-hit != 'true'
+```
+
+
 ## PHP - Composer
 
-```yaml  
+```yaml
 - name: Get Composer Cache Directory
   id: composer-cache
   run: |
@@ -199,14 +291,32 @@ Replace `~/.cache/pip` with the correct `path` if not using Ubuntu.
       ${{ runner.os }}-pip-
 ```
 
+### Using pip to get cache location
+
+> Note: This requires pip 20.1+
+```yaml
+- name: Get pip cache dir
+  id: pip-cache
+  run: |
+    echo "::set-output name=dir::$(pip cache dir)"
+
+- name: pip cache
+  uses: actions/cache@v1
+  with:
+    path: ${{ steps.pip-cache.outputs.dir }}
+    key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}
+    restore-keys: |
+      ${{ runner.os }}-pip-
+```
+
 ### Using a script to get cache location
 
 > Note: This uses an internal pip API and may not always work
 ```yaml
-- name: Get pip cache
-   id: pip-cache
-   run: |
-     python -c "from pip._internal.locations import USER_CACHE_DIR; print('::set-output name=dir::' + USER_CACHE_DIR)"
+- name: Get pip cache dir
+ id: pip-cache
+ run: |
+   python -c "from pip._internal.locations import USER_CACHE_DIR; print('::set-output name=dir::' + USER_CACHE_DIR)"
 
 - uses: actions/cache@v1
   with:
@@ -216,15 +326,72 @@ Replace `~/.cache/pip` with the correct `path` if not using Ubuntu.
       ${{ runner.os }}-pip-
 ```
 
-## Ruby - Gem
+## R - renv
+
+For renv, the cache directory will vary by OS. Look at https://rstudio.github.io/renv/articles/renv.html#cache
+
+Locations:
+ - Ubuntu: `~/.local/share/renv`
+ - macOS: `~/Library/Application Support/renv`
+ - Windows: `%LOCALAPPDATA%/renv`
+
+### Simple example
+```yaml
+- uses: actions/cache@v1
+  with:
+    path: ~/.local/share/renv
+    key: ${{ runner.os }}-renv-${{ hashFiles('**/renv.lock') }}
+    restore-keys: |
+      ${{ runner.os }}-renv-
+```
+
+Replace `~/.local/share/renv` with the correct `path` if not using Ubuntu.
+
+### Multiple OS's in a workflow
+
+```yaml
+- uses: actions/cache@v1
+  if: startsWith(runner.os, 'Linux')
+  with:
+    path: ~/.local/share/renv
+    key: ${{ runner.os }}-renv-${{ hashFiles('**/renv.lock') }}
+    restore-keys: |
+      ${{ runner.os }}-renv-
+
+- uses: actions/cache@v1
+  if: startsWith(runner.os, 'macOS')
+  with:
+    path: ~/Library/Application Support/renv
+    key: ${{ runner.os }}-renv-${{ hashFiles('**/renv.lock') }}
+    restore-keys: |
+      ${{ runner.os }}-renv-
+
+- uses: actions/cache@v1
+  if: startsWith(runner.os, 'Windows')
+  with:
+    path: ~\AppData\Local\renv
+    key: ${{ runner.os }}-renv-${{ hashFiles('**/renv.lock') }}
+    restore-keys: |
+      ${{ runner.os }}-renv-
+```
+
+## Ruby - Bundler
 
 ```yaml
 - uses: actions/cache@v1
   with:
     path: vendor/bundle
-    key: ${{ runner.os }}-gem-${{ hashFiles('**/Gemfile.lock') }}
+    key: ${{ runner.os }}-gems-${{ hashFiles('**/Gemfile.lock') }}
     restore-keys: |
-      ${{ runner.os }}-gem-
+      ${{ runner.os }}-gems-
+```
+When dependencies are installed later in the workflow, we must specify the same path for the bundler.
+
+```yaml
+- name: Bundle install
+  run: |
+    bundle config path vendor/bundle
+    bundle install --jobs 4 --retry 3
 ```
 
 ## Rust - Cargo
@@ -247,6 +414,21 @@ Replace `~/.cache/pip` with the correct `path` if not using Ubuntu.
     key: ${{ runner.os }}-cargo-build-target-${{ hashFiles('**/Cargo.lock') }}
 ```
 
+## Scala - SBT
+
+```yaml
+- name: Cache SBT ivy cache
+  uses: actions/cache@v1
+  with:
+    path: ~/.ivy2/cache
+    key: ${{ runner.os }}-sbt-ivy-cache-${{ hashFiles('**/build.sbt') }}
+- name: Cache SBT
+  uses: actions/cache@v1
+  with:
+    path: ~/.sbt
+    key: ${{ runner.os }}-sbt-${{ hashFiles('**/build.sbt') }}
+```
+
 ## Swift, Objective-C - Carthage
 
 ```yaml
@@ -268,3 +450,14 @@ Replace `~/.cache/pip` with the correct `path` if not using Ubuntu.
     restore-keys: |
       ${{ runner.os }}-pods-
 ```
+
+## Swift - Swift Package Manager
+
+```yaml
+- uses: actions/cache@v1
+  with:
+    path: .build
+    key: ${{ runner.os }}-spm-${{ hashFiles('**/Package.resolved') }}
+    restore-keys: |
+      ${{ runner.os }}-spm-
+```

package.json

@@ -1,16 +1,15 @@
 {
   "name": "cache",
-  "version": "1.0.3",
+  "version": "1.1.2",
   "private": true,
   "description": "Cache dependencies and build outputs",
   "main": "dist/restore/index.js",
   "scripts": {
-    "build": "tsc",
+    "build": "tsc && ncc build -o dist/restore src/restore.ts && ncc build -o dist/save src/save.ts",
     "test": "tsc --noEmit && jest --coverage",
     "lint": "eslint **/*.ts --cache",
     "format": "prettier --write **/*.ts",
-    "format-check": "prettier --check **/*.ts",
-    "release": "ncc build -o dist/restore src/restore.ts && ncc build -o dist/save src/save.ts && git add -f dist/"
+    "format-check": "prettier --check **/*.ts"
   },
   "repository": {
     "type": "git",
@@ -26,8 +25,9 @@
   "dependencies": {
     "@actions/core": "^1.2.0",
     "@actions/exec": "^1.0.1",
+    "@actions/glob": "^0.1.0",
+    "@actions/http-client": "^1.0.8",
     "@actions/io": "^1.0.1",
-    "typed-rest-client": "^1.5.0",
     "uuid": "^3.3.3"
   },
   "devDependencies": {
@@ -43,11 +43,12 @@
     "eslint-plugin-import": "^2.18.2",
     "eslint-plugin-jest": "^23.0.3",
     "eslint-plugin-prettier": "^3.1.1",
+    "eslint-plugin-simple-import-sort": "^5.0.2",
     "jest": "^24.8.0",
     "jest-circus": "^24.7.1",
     "nock": "^11.7.0",
-    "prettier": "1.18.2",
+    "prettier": "^1.19.1",
     "ts-jest": "^24.0.2",
-    "typescript": "^3.6.4"
+    "typescript": "^3.7.3"
   }
 }

src/cacheHttpClient.ts

@@ -1,26 +1,70 @@
 import * as core from "@actions/core";
+import { HttpClient, HttpCodes } from "@actions/http-client";
+import { BearerCredentialHandler } from "@actions/http-client/auth";
+import {
+    IHttpClientResponse,
+    IRequestOptions,
+    ITypedResponse
+} from "@actions/http-client/interfaces";
+import * as crypto from "crypto";
 import * as fs from "fs";
-import { BearerCredentialHandler } from "typed-rest-client/Handlers";
-import { HttpClient } from "typed-rest-client/HttpClient";
-import { IHttpClientResponse } from "typed-rest-client/Interfaces";
-import { IRequestOptions, RestClient } from "typed-rest-client/RestClient";
-import { ArtifactCacheEntry } from "./contracts";
+import * as stream from "stream";
+import * as util from "util";
 
-function getCacheUrl(): string {
+import { CompressionMethod, Inputs, SocketTimeout } from "./constants";
+import {
+    ArtifactCacheEntry,
+    CacheOptions,
+    CommitCacheRequest,
+    ReserveCacheRequest,
+    ReserveCacheResponse
+} from "./contracts";
+import * as utils from "./utils/actionUtils";
+
+const versionSalt = "1.0";
+
+function isSuccessStatusCode(statusCode?: number): boolean {
+    if (!statusCode) {
+        return false;
+    }
+    return statusCode >= 200 && statusCode < 300;
+}
+
+function isServerErrorStatusCode(statusCode?: number): boolean {
+    if (!statusCode) {
+        return true;
+    }
+    return statusCode >= 500;
+}
+
+function isRetryableStatusCode(statusCode?: number): boolean {
+    if (!statusCode) {
+        return false;
+    }
+    const retryableStatusCodes = [
+        HttpCodes.BadGateway,
+        HttpCodes.ServiceUnavailable,
+        HttpCodes.GatewayTimeout
+    ];
+    return retryableStatusCodes.includes(statusCode);
+}
+
+function getCacheApiUrl(resource: string): string {
     // Ideally we just use ACTIONS_CACHE_URL
-    const cacheUrl: string = (
+    const baseUrl: string = (
         process.env["ACTIONS_CACHE_URL"] ||
         process.env["ACTIONS_RUNTIME_URL"] ||
         ""
     ).replace("pipelines", "artifactcache");
-    if (!cacheUrl) {
+    if (!baseUrl) {
         throw new Error(
             "Cache Service Url not found, unable to restore cache."
         );
     }
 
-    core.debug(`Cache Url: ${cacheUrl}`);
-    return cacheUrl;
+    const url = `${baseUrl}_apis/artifactcache/${resource}`;
+    core.debug(`Resource Url: ${url}`);
+    return url;
 }
 
 function createAcceptHeader(type: string, apiVersion: string): string {
@@ -29,42 +73,132 @@ function createAcceptHeader(type: string, apiVersion: string): string {
 
 function getRequestOptions(): IRequestOptions {
     const requestOptions: IRequestOptions = {
-        acceptHeader: createAcceptHeader("application/json", "5.2-preview.1")
+        headers: {
+            Accept: createAcceptHeader("application/json", "6.0-preview.1")
+        }
     };
 
     return requestOptions;
 }
 
-export async function getCacheEntry(
-    keys: string[]
-): Promise<ArtifactCacheEntry | null> {
-    const cacheUrl = getCacheUrl();
+function createHttpClient(): HttpClient {
     const token = process.env["ACTIONS_RUNTIME_TOKEN"] || "";
     const bearerCredentialHandler = new BearerCredentialHandler(token);
 
-    const resource = `_apis/artifactcache/cache?keys=${encodeURIComponent(
-        keys.join(",")
-    )}`;
-
-    const restClient = new RestClient("actions/cache", cacheUrl, [
-        bearerCredentialHandler
-    ]);
-
-    const response = await restClient.get<ArtifactCacheEntry>(
-        resource,
+    return new HttpClient(
+        "actions/cache",
+        [bearerCredentialHandler],
         getRequestOptions()
     );
+}
+
+export function getCacheVersion(compressionMethod?: CompressionMethod): string {
+    const components = [core.getInput(Inputs.Path, { required: true })].concat(
+        compressionMethod == CompressionMethod.Zstd ? [compressionMethod] : []
+    );
+
+    // Add salt to cache version to support breaking changes in cache entry
+    components.push(versionSalt);
+
+    return crypto
+        .createHash("sha256")
+        .update(components.join("|"))
+        .digest("hex");
+}
+
+export async function retry<T>(
+    name: string,
+    method: () => Promise<T>,
+    getStatusCode: (T) => number | undefined,
+    maxAttempts = 2
+): Promise<T> {
+    let response: T | undefined = undefined;
+    let statusCode: number | undefined = undefined;
+    let isRetryable = false;
+    let errorMessage = "";
+    let attempt = 1;
+
+    while (attempt <= maxAttempts) {
+        try {
+            response = await method();
+            statusCode = getStatusCode(response);
+
+            if (!isServerErrorStatusCode(statusCode)) {
+                return response;
+            }
+
+            isRetryable = isRetryableStatusCode(statusCode);
+            errorMessage = `Cache service responded with ${statusCode}`;
+        } catch (error) {
+            isRetryable = true;
+            errorMessage = error.message;
+        }
+
+        core.debug(
+            `${name} - Attempt ${attempt} of ${maxAttempts} failed with error: ${errorMessage}`
+        );
+
+        if (!isRetryable) {
+            core.debug(`${name} - Error is not retryable`);
+            break;
+        }
+
+        attempt++;
+    }
+
+    throw Error(`${name} failed: ${errorMessage}`);
+}
+
+export async function retryTypedResponse<T>(
+    name: string,
+    method: () => Promise<ITypedResponse<T>>,
+    maxAttempts = 2
+): Promise<ITypedResponse<T>> {
+    return await retry(
+        name,
+        method,
+        (response: ITypedResponse<T>) => response.statusCode,
+        maxAttempts
+    );
+}
+
+export async function retryHttpClientResponse<T>(
+    name: string,
+    method: () => Promise<IHttpClientResponse>,
+    maxAttempts = 2
+): Promise<IHttpClientResponse> {
+    return await retry(
+        name,
+        method,
+        (response: IHttpClientResponse) => response.message.statusCode,
+        maxAttempts
+    );
+}
+
+export async function getCacheEntry(
+    keys: string[],
+    options?: CacheOptions
+): Promise<ArtifactCacheEntry | null> {
+    const httpClient = createHttpClient();
+    const version = getCacheVersion(options?.compressionMethod);
+    const resource = `cache?keys=${encodeURIComponent(
+        keys.join(",")
+    )}&version=${version}`;
+
+    const response = await retryTypedResponse("getCacheEntry", () =>
+        httpClient.getJson<ArtifactCacheEntry>(getCacheApiUrl(resource))
+    );
+
     if (response.statusCode === 204) {
         return null;
     }
-    if (response.statusCode !== 200) {
-        throw new Error(`Cache service responded with ${response.statusCode}`);
-    }
+
     const cacheResult = response.result;
-    if (!cacheResult || !cacheResult.archiveLocation) {
+    const cacheDownloadUrl = cacheResult?.archiveLocation;
+    if (!cacheDownloadUrl) {
         throw new Error("Cache not found.");
     }
-    core.setSecret(cacheResult.archiveLocation);
+    core.setSecret(cacheDownloadUrl);
     core.debug(`Cache Result:`);
     core.debug(JSON.stringify(cacheResult));
 
@@ -73,56 +207,213 @@ export async function getCacheEntry(
 
 async function pipeResponseToStream(
     response: IHttpClientResponse,
-    stream: NodeJS.WritableStream
+    output: NodeJS.WritableStream
 ): Promise<void> {
-    return new Promise(resolve => {
-        response.message.pipe(stream).on("close", () => {
-            resolve();
-        });
-    });
+    const pipeline = util.promisify(stream.pipeline);
+    await pipeline(response.message, output);
 }
 
 export async function downloadCache(
-    cacheEntry: ArtifactCacheEntry,
+    archiveLocation: string,
     archivePath: string
 ): Promise<void> {
     const stream = fs.createWriteStream(archivePath);
     const httpClient = new HttpClient("actions/cache");
-    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
-    const downloadResponse = await httpClient.get(cacheEntry.archiveLocation!);
+    const downloadResponse = await retryHttpClientResponse(
+        "downloadCache",
+        () => httpClient.get(archiveLocation)
+    );
+
+    // Abort download if no traffic received over the socket.
+    downloadResponse.message.socket.setTimeout(SocketTimeout, () => {
+        downloadResponse.message.destroy();
+        core.debug(
+            `Aborting download, socket timed out after ${SocketTimeout} ms`
+        );
+    });
+
     await pipeResponseToStream(downloadResponse, stream);
+
+    // Validate download size.
+    const contentLengthHeader =
+        downloadResponse.message.headers["content-length"];
+
+    if (contentLengthHeader) {
+        const expectedLength = parseInt(contentLengthHeader);
+        const actualLength = utils.getArchiveFileSize(archivePath);
+
+        if (actualLength != expectedLength) {
+            throw new Error(
+                `Incomplete download. Expected file size: ${expectedLength}, actual file size: ${actualLength}`
+            );
+        }
+    } else {
+        core.debug("Unable to validate download, no Content-Length header");
+    }
+}
+
+// Reserve Cache
+export async function reserveCache(
+    key: string,
+    options?: CacheOptions
+): Promise<number> {
+    const httpClient = createHttpClient();
+    const version = getCacheVersion(options?.compressionMethod);
+
+    const reserveCacheRequest: ReserveCacheRequest = {
+        key,
+        version
+    };
+    const response = await retryTypedResponse("reserveCache", () =>
+        httpClient.postJson<ReserveCacheResponse>(
+            getCacheApiUrl("caches"),
+            reserveCacheRequest
+        )
+    );
+
+    return response?.result?.cacheId ?? -1;
+}
+
+function getContentRange(start: number, end: number): string {
+    // Format: `bytes start-end/filesize
+    // start and end are inclusive
+    // filesize can be *
+    // For a 200 byte chunk starting at byte 0:
+    // Content-Range: bytes 0-199/*
+    return `bytes ${start}-${end}/*`;
+}
+
+async function uploadChunk(
+    httpClient: HttpClient,
+    resourceUrl: string,
+    openStream: () => NodeJS.ReadableStream,
+    start: number,
+    end: number
+): Promise<void> {
+    core.debug(
+        `Uploading chunk of size ${end -
+            start +
+            1} bytes at offset ${start} with content range: ${getContentRange(
+            start,
+            end
+        )}`
+    );
+    const additionalHeaders = {
+        "Content-Type": "application/octet-stream",
+        "Content-Range": getContentRange(start, end)
+    };
+
+    const uploadChunkRequest = async (): Promise<IHttpClientResponse> => {
+        return await httpClient.sendStream(
+            "PATCH",
+            resourceUrl,
+            openStream(),
+            additionalHeaders
+        );
+    };
+
+    await retryHttpClientResponse(
+        `uploadChunk (start: ${start}, end: ${end})`,
+        uploadChunkRequest
+    );
+}
+
+function parseEnvNumber(key: string): number | undefined {
+    const value = Number(process.env[key]);
+    if (Number.isNaN(value) || value < 0) {
+        return undefined;
+    }
+    return value;
+}
+
+async function uploadFile(
+    httpClient: HttpClient,
+    cacheId: number,
+    archivePath: string
+): Promise<void> {
+    // Upload Chunks
+    const fileSize = fs.statSync(archivePath).size;
+    const resourceUrl = getCacheApiUrl(`caches/${cacheId.toString()}`);
+    const fd = fs.openSync(archivePath, "r");
+
+    const concurrency = parseEnvNumber("CACHE_UPLOAD_CONCURRENCY") ?? 4; // # of HTTP requests in parallel
+    const MAX_CHUNK_SIZE =
+        parseEnvNumber("CACHE_UPLOAD_CHUNK_SIZE") ?? 32 * 1024 * 1024; // 32 MB Chunks
+    core.debug(`Concurrency: ${concurrency} and Chunk Size: ${MAX_CHUNK_SIZE}`);
+
+    const parallelUploads = [...new Array(concurrency).keys()];
+    core.debug("Awaiting all uploads");
+    let offset = 0;
+
+    try {
+        await Promise.all(
+            parallelUploads.map(async () => {
+                while (offset < fileSize) {
+                    const chunkSize = Math.min(
+                        fileSize - offset,
+                        MAX_CHUNK_SIZE
+                    );
+                    const start = offset;
+                    const end = offset + chunkSize - 1;
+                    offset += MAX_CHUNK_SIZE;
+
+                    await uploadChunk(
+                        httpClient,
+                        resourceUrl,
+                        () =>
+                            fs.createReadStream(archivePath, {
+                                fd,
+                                start,
+                                end,
+                                autoClose: false
+                            }),
+                        start,
+                        end
+                    );
+                }
+            })
+        );
+    } finally {
+        fs.closeSync(fd);
+    }
+    return;
+}
+
+async function commitCache(
+    httpClient: HttpClient,
+    cacheId: number,
+    filesize: number
+): Promise<ITypedResponse<null>> {
+    const commitCacheRequest: CommitCacheRequest = { size: filesize };
+    return await retryTypedResponse("commitCache", () =>
+        httpClient.postJson<null>(
+            getCacheApiUrl(`caches/${cacheId.toString()}`),
+            commitCacheRequest
+        )
+    );
 }
 
 export async function saveCache(
-    key: string,
+    cacheId: number,
     archivePath: string
 ): Promise<void> {
-    const stream = fs.createReadStream(archivePath);
+    const httpClient = createHttpClient();
 
-    const cacheUrl = getCacheUrl();
-    const token = process.env["ACTIONS_RUNTIME_TOKEN"] || "";
-    const bearerCredentialHandler = new BearerCredentialHandler(token);
+    core.debug("Upload cache");
+    await uploadFile(httpClient, cacheId, archivePath);
 
-    const resource = `_apis/artifactcache/cache/${encodeURIComponent(key)}`;
-    const postUrl = cacheUrl + resource;
-
-    const restClient = new RestClient("actions/cache", undefined, [
-        bearerCredentialHandler
-    ]);
-
-    const requestOptions = getRequestOptions();
-    requestOptions.additionalHeaders = {
-        "Content-Type": "application/octet-stream"
-    };
-
-    const response = await restClient.uploadStream<void>(
-        "POST",
-        postUrl,
-        stream,
-        requestOptions
+    // Commit Cache
+    core.debug("Commiting cache");
+    const cacheSize = utils.getArchiveFileSize(archivePath);
+    const commitCacheResponse = await commitCache(
+        httpClient,
+        cacheId,
+        cacheSize
     );
-    if (response.statusCode !== 200) {
-        throw new Error(`Cache service responded with ${response.statusCode}`);
+    if (!isSuccessStatusCode(commitCacheResponse.statusCode)) {
+        throw new Error(
+            `Cache service responded with ${commitCacheResponse.statusCode} during commit cache.`
+        );
     }
 
     core.info("Cache saved successfully");

src/constants.ts

@@ -18,3 +18,18 @@ export enum Events {
     Push = "push",
     PullRequest = "pull_request"
 }
+
+export enum CacheFilename {
+    Gzip = "cache.tgz",
+    Zstd = "cache.tzst"
+}
+
+export enum CompressionMethod {
+    Gzip = "gzip",
+    Zstd = "zstd"
+}
+
+// Socket timeout in milliseconds during download.  If no traffic is received
+// over the socket during this period, the socket is destroyed and the download
+// is aborted.
+export const SocketTimeout = 5000;

src/contracts.d.ts

@@ -1,6 +1,25 @@
+import { CompressionMethod } from "./constants";
+
 export interface ArtifactCacheEntry {
     cacheKey?: string;
     scope?: string;
     creationTime?: string;
     archiveLocation?: string;
 }
+
+export interface CommitCacheRequest {
+    size: number;
+}
+
+export interface ReserveCacheRequest {
+    key: string;
+    version?: string;
+}
+
+export interface ReserveCacheResponse {
+    cacheId: number;
+}
+
+export interface CacheOptions {
+    compressionMethod?: CompressionMethod;
+}

src/restore.ts

@@ -1,9 +1,9 @@
 import * as core from "@actions/core";
-import { exec } from "@actions/exec";
-import * as io from "@actions/io";
 import * as path from "path";
+
 import * as cacheHttpClient from "./cacheHttpClient";
 import { Events, Inputs, State } from "./constants";
+import { extractTar } from "./tar";
 import * as utils from "./utils/actionUtils";
 
 async function run(): Promise<void> {
@@ -20,11 +20,6 @@ async function run(): Promise<void> {
             return;
         }
 
-        const cachePath = utils.resolvePath(
-            core.getInput(Inputs.Path, { required: true })
-        );
-        core.debug(`Cache Path: ${cachePath}`);
-
         const primaryKey = core.getInput(Inputs.Key, { required: true });
         core.saveState(State.CacheKey, primaryKey);
 
@@ -59,55 +54,49 @@ async function run(): Promise<void> {
             }
         }
 
+        const compressionMethod = await utils.getCompressionMethod();
+
         try {
-            const cacheEntry = await cacheHttpClient.getCacheEntry(keys);
-            if (!cacheEntry) {
-                core.info(
-                    `Cache not found for input keys: ${keys.join(", ")}.`
-                );
+            const cacheEntry = await cacheHttpClient.getCacheEntry(keys, {
+                compressionMethod: compressionMethod
+            });
+            if (!cacheEntry?.archiveLocation) {
+                core.info(`Cache not found for input keys: ${keys.join(", ")}`);
                 return;
             }
 
             const archivePath = path.join(
                 await utils.createTempDirectory(),
-                "cache.tgz"
+                utils.getCacheFileName(compressionMethod)
             );
             core.debug(`Archive Path: ${archivePath}`);
 
             // Store the cache result
             utils.setCacheState(cacheEntry);
 
-            // Download the cache from the cache entry
-            await cacheHttpClient.downloadCache(cacheEntry, archivePath);
+            try {
+                // Download the cache from the cache entry
+                await cacheHttpClient.downloadCache(
+                    cacheEntry.archiveLocation,
+                    archivePath
+                );
 
-            const archiveFileSize = utils.getArchiveFileSize(archivePath);
-            core.info(
-                `Cache Size: ~${Math.round(
-                    archiveFileSize / (1024 * 1024)
-                )} MB (${archiveFileSize} B)`
-            );
+                const archiveFileSize = utils.getArchiveFileSize(archivePath);
+                core.info(
+                    `Cache Size: ~${Math.round(
+                        archiveFileSize / (1024 * 1024)
+                    )} MB (${archiveFileSize} B)`
+                );
 
-            // Create directory to extract tar into
-            await io.mkdirP(cachePath);
-
-            // http://man7.org/linux/man-pages/man1/tar.1.html
-            // tar [-options] <name of the tar archive> [files or directories which to add into archive]
-            const IS_WINDOWS = process.platform === "win32";
-            const args = IS_WINDOWS
-                ? [
-                      "-xz",
-                      "--force-local",
-                      "-f",
-                      archivePath.replace(/\\/g, "/"),
-                      "-C",
-                      cachePath.replace(/\\/g, "/")
-                  ]
-                : ["-xz", "-f", archivePath, "-C", cachePath];
-
-            const tarPath = await io.which("tar", true);
-            core.debug(`Tar Path: ${tarPath}`);
-
-            await exec(`"${tarPath}"`, args);
+                await extractTar(archivePath, compressionMethod);
+            } finally {
+                // Try to delete the archive to save space
+                try {
+                    await utils.unlinkFile(archivePath);
+                } catch (error) {
+                    core.debug(`Failed to delete archive: ${error}`);
+                }
+            }
 
             const isExactKeyMatch = utils.isExactKeyMatch(
                 primaryKey,

src/save.ts

@@ -1,9 +1,9 @@
 import * as core from "@actions/core";
-import { exec } from "@actions/exec";
-import * as io from "@actions/io";
 import * as path from "path";
+
 import * as cacheHttpClient from "./cacheHttpClient";
 import { Events, Inputs, State } from "./constants";
+import { createTar } from "./tar";
 import * as utils from "./utils/actionUtils";
 
 async function run(): Promise<void> {
@@ -35,49 +35,53 @@ async function run(): Promise<void> {
             return;
         }
 
-        const cachePath = utils.resolvePath(
-            core.getInput(Inputs.Path, { required: true })
-        );
-        core.debug(`Cache Path: ${cachePath}`);
+        const compressionMethod = await utils.getCompressionMethod();
 
-        const archivePath = path.join(
-            await utils.createTempDirectory(),
-            "cache.tgz"
+        core.debug("Reserving Cache");
+        const cacheId = await cacheHttpClient.reserveCache(primaryKey, {
+            compressionMethod: compressionMethod
+        });
+        if (cacheId == -1) {
+            core.info(
+                `Unable to reserve cache with key ${primaryKey}, another job may be creating this cache.`
+            );
+            return;
+        }
+        core.debug(`Cache ID: ${cacheId}`);
+        const cachePaths = await utils.resolvePaths(
+            core
+                .getInput(Inputs.Path, { required: true })
+                .split("\n")
+                .filter(x => x !== "")
         );
+
+        core.debug("Cache Paths:");
+        core.debug(`${JSON.stringify(cachePaths)}`);
+
+        const archiveFolder = await utils.createTempDirectory();
+        const archivePath = path.join(
+            archiveFolder,
+            utils.getCacheFileName(compressionMethod)
+        );
+
         core.debug(`Archive Path: ${archivePath}`);
 
-        // http://man7.org/linux/man-pages/man1/tar.1.html
-        // tar [-options] <name of the tar archive> [files or directories which to add into archive]
-        const IS_WINDOWS = process.platform === "win32";
-        const args = IS_WINDOWS
-            ? [
-                  "-cz",
-                  "--force-local",
-                  "-f",
-                  archivePath.replace(/\\/g, "/"),
-                  "-C",
-                  cachePath.replace(/\\/g, "/"),
-                  "."
-              ]
-            : ["-cz", "-f", archivePath, "-C", cachePath, "."];
+        await createTar(archiveFolder, cachePaths, compressionMethod);
 
-        const tarPath = await io.which("tar", true);
-        core.debug(`Tar Path: ${tarPath}`);
-        await exec(`"${tarPath}"`, args);
-
-        const fileSizeLimit = 400 * 1024 * 1024; // 400MB
+        const fileSizeLimit = 5 * 1024 * 1024 * 1024; // 5GB per repo limit
         const archiveFileSize = utils.getArchiveFileSize(archivePath);
         core.debug(`File Size: ${archiveFileSize}`);
         if (archiveFileSize > fileSizeLimit) {
             utils.logWarning(
                 `Cache size of ~${Math.round(
                     archiveFileSize / (1024 * 1024)
-                )} MB (${archiveFileSize} B) is over the 400MB limit, not saving cache.`
+                )} MB (${archiveFileSize} B) is over the 5GB limit, not saving cache.`
             );
             return;
         }
 
-        await cacheHttpClient.saveCache(primaryKey, archivePath);
+        core.debug(`Saving Cache (ID: ${cacheId})`);
+        await cacheHttpClient.saveCache(cacheId, archivePath);
     } catch (error) {
         utils.logWarning(error.message);
     }

src/tar.ts

@@ -0,0 +1,87 @@
+import { exec } from "@actions/exec";
+import * as io from "@actions/io";
+import { existsSync, writeFileSync } from "fs";
+import * as path from "path";
+
+import { CompressionMethod } from "./constants";
+import * as utils from "./utils/actionUtils";
+
+async function getTarPath(args: string[]): Promise<string> {
+    // Explicitly use BSD Tar on Windows
+    const IS_WINDOWS = process.platform === "win32";
+    if (IS_WINDOWS) {
+        const systemTar = `${process.env["windir"]}\\System32\\tar.exe`;
+        if (existsSync(systemTar)) {
+            return systemTar;
+        } else if (await utils.useGnuTar()) {
+            args.push("--force-local");
+        }
+    }
+    return await io.which("tar", true);
+}
+
+async function execTar(args: string[], cwd?: string): Promise<void> {
+    try {
+        await exec(`"${await getTarPath(args)}"`, args, { cwd: cwd });
+    } catch (error) {
+        throw new Error(`Tar failed with error: ${error?.message}`);
+    }
+}
+
+function getWorkingDirectory(): string {
+    return process.env["GITHUB_WORKSPACE"] ?? process.cwd();
+}
+
+export async function extractTar(
+    archivePath: string,
+    compressionMethod: CompressionMethod
+): Promise<void> {
+    // Create directory to extract tar into
+    const workingDirectory = getWorkingDirectory();
+    await io.mkdirP(workingDirectory);
+    // --d: Decompress.
+    // --long=#: Enables long distance matching with # bits. Maximum is 30 (1GB) on 32-bit OS and 31 (2GB) on 64-bit.
+    // Using 30 here because we also support 32-bit self-hosted runners.
+    const args = [
+        ...(compressionMethod == CompressionMethod.Zstd
+            ? ["--use-compress-program", "zstd -d --long=30"]
+            : ["-z"]),
+        "-xf",
+        archivePath.replace(new RegExp("\\" + path.sep, "g"), "/"),
+        "-P",
+        "-C",
+        workingDirectory.replace(new RegExp("\\" + path.sep, "g"), "/")
+    ];
+    await execTar(args);
+}
+
+export async function createTar(
+    archiveFolder: string,
+    sourceDirectories: string[],
+    compressionMethod: CompressionMethod
+): Promise<void> {
+    // Write source directories to manifest.txt to avoid command length limits
+    const manifestFilename = "manifest.txt";
+    const cacheFileName = utils.getCacheFileName(compressionMethod);
+    writeFileSync(
+        path.join(archiveFolder, manifestFilename),
+        sourceDirectories.join("\n")
+    );
+    // -T#: Compress using # working thread. If # is 0, attempt to detect and use the number of physical CPU cores.
+    // --long=#: Enables long distance matching with # bits. Maximum is 30 (1GB) on 32-bit OS and 31 (2GB) on 64-bit.
+    // Using 30 here because we also support 32-bit self-hosted runners.
+    const workingDirectory = getWorkingDirectory();
+    const args = [
+        ...(compressionMethod == CompressionMethod.Zstd
+            ? ["--use-compress-program", "zstd -T0 --long=30"]
+            : ["-z"]),
+        "-cf",
+        cacheFileName.replace(new RegExp("\\" + path.sep, "g"), "/"),
+        "-P",
+        "-C",
+        workingDirectory.replace(new RegExp("\\" + path.sep, "g"), "/"),
+        "--files-from",
+        manifestFilename
+    ];
+    await execTar(args, archiveFolder);
+}

src/utils/actionUtils.ts

@@ -1,11 +1,20 @@
 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 * as fs from "fs";
 import * as os from "os";
 import * as path from "path";
+import * as util from "util";
 import * as uuidV4 from "uuid/v4";
 
-import { Events, Outputs, State } from "../constants";
+import {
+    CacheFilename,
+    CompressionMethod,
+    Events,
+    Outputs,
+    State
+} from "../constants";
 import { ArtifactCacheEntry } from "../contracts";
 
 // From https://github.com/actions/toolkit/blob/master/packages/tool-cache/src/tool-cache.ts#L23
@@ -28,6 +37,7 @@ export async function createTempDirectory(): Promise<string> {
         }
         tempDirectory = path.join(baseLocation, "actions", "temp");
     }
+
     const dest = path.join(tempDirectory, uuidV4.default());
     await io.mkdirP(dest);
     return dest;
@@ -82,16 +92,21 @@ export function logWarning(message: string): void {
     core.info(`${warningPrefix}${message}`);
 }
 
-export function resolvePath(filePath: string): string {
-    if (filePath[0] === "~") {
-        const home = os.homedir();
-        if (!home) {
-            throw new Error("Unable to resolve `~` to HOME");
-        }
-        return path.join(home, filePath.slice(1));
+export async function resolvePaths(patterns: string[]): Promise<string[]> {
+    const paths: string[] = [];
+    const workspace = process.env["GITHUB_WORKSPACE"] ?? process.cwd();
+    const globber = await glob.create(patterns.join("\n"), {
+        implicitDescendants: false
+    });
+
+    for await (const file of globber.globGenerator()) {
+        const relativeFile = path.relative(workspace, file);
+        core.debug(`Matched: ${relativeFile}`);
+        // Paths are made relative so the tar entries are all relative to the root of the workspace.
+        paths.push(`${relativeFile}`);
     }
 
-    return path.resolve(filePath);
+    return paths;
 }
 
 export function getSupportedEvents(): string[] {
@@ -105,3 +120,53 @@ export function isValidEvent(): boolean {
     const githubEvent = process.env[Events.Key] || "";
     return getSupportedEvents().includes(githubEvent);
 }
+
+export function unlinkFile(path: fs.PathLike): Promise<void> {
+    return util.promisify(fs.unlink)(path);
+}
+
+async function getVersion(app: string): Promise<string> {
+    core.debug(`Checking ${app} --version`);
+    let versionOutput = "";
+    try {
+        await exec.exec(`${app} --version`, [], {
+            ignoreReturnCode: true,
+            silent: true,
+            listeners: {
+                stdout: (data: Buffer): string =>
+                    (versionOutput += data.toString()),
+                stderr: (data: Buffer): string =>
+                    (versionOutput += data.toString())
+            }
+        });
+    } catch (err) {
+        core.debug(err.message);
+    }
+
+    versionOutput = versionOutput.trim();
+    core.debug(versionOutput);
+    return versionOutput;
+}
+
+export async function getCompressionMethod(): Promise<CompressionMethod> {
+    // Disabling zstd on Windows due to https://github.com/actions/cache/issues/301
+    if (os.platform() === "win32") {
+        return CompressionMethod.Gzip;
+    }
+
+    const versionOutput = await getVersion("zstd");
+    return versionOutput.toLowerCase().includes("zstd command line interface")
+        ? CompressionMethod.Zstd
+        : CompressionMethod.Gzip;
+}
+
+export function getCacheFileName(compressionMethod: CompressionMethod): string {
+    return compressionMethod == CompressionMethod.Zstd
+        ? CacheFilename.Zstd
+        : CacheFilename.Gzip;
+}
+
+export async function useGnuTar(): Promise<boolean> {
+    const versionOutput = await getVersion("tar");
+    return versionOutput.toLowerCase().includes("gnu tar");
+}