Use faster D: drive on windows for Gradle User Home and Gradle downloads

sources/src/execution/provision.ts

@@ -100,7 +100,7 @@ async function installGradleVersion(versionInfo: GradleVersionInfo): Promise<str
 }
 
 async function locateGradleAndDownloadIfRequired(versionInfo: GradleVersionInfo): Promise<string> {
-    const installsDir = path.join(os.homedir(), 'gradle-installations/installs')
+    const installsDir = path.join(getProvisionDir(), 'installs')
     const installDir = path.join(installsDir, `gradle-${versionInfo.version}`)
     if (fs.existsSync(installDir)) {
         core.info(`Gradle installation already exists at ${installDir}`)
@@ -119,7 +119,7 @@ async function locateGradleAndDownloadIfRequired(versionInfo: GradleVersionInfo)
 }
 
 async function downloadAndCacheGradleDistribution(versionInfo: GradleVersionInfo): Promise<string> {
-    const downloadPath = path.join(os.homedir(), `gradle-installations/downloads/gradle-${versionInfo.version}-bin.zip`)
+    const downloadPath = path.join(getProvisionDir(), `downloads/gradle-${versionInfo.version}-bin.zip`)
 
     // TODO: Convert this to a class and inject config
     const cacheConfig = new CacheConfig()
@@ -152,6 +152,11 @@ async function downloadAndCacheGradleDistribution(versionInfo: GradleVersionInfo
     return downloadPath
 }
 
+function getProvisionDir(): string {
+    const tmpDir = process.env['RUNNER_TEMP'] ?? os.tmpdir()
+    return path.join(tmpDir, `.gradle-actions/gradle-installations`)
+}
+
 async function downloadGradleDistribution(versionInfo: GradleVersionInfo, downloadPath: string): Promise<void> {
     await toolCache.downloadTool(versionInfo.downloadUrl, downloadPath)
     core.info(`Downloaded ${versionInfo.downloadUrl} to ${downloadPath} (size ${fs.statSync(downloadPath).size})`)

sources/src/setup-gradle.ts

@@ -1,5 +1,6 @@
 import * as core from '@actions/core'
 import * as exec from '@actions/exec'
+import * as fs from 'fs'
 import * as path from 'path'
 import * as os from 'os'
 import * as caches from './caching/caches'
@@ -79,7 +80,22 @@ async function determineGradleUserHome(): Promise<string> {
         return path.resolve(rootDir, customGradleUserHome)
     }
 
-    return path.resolve(await determineUserHome(), '.gradle')
+    const defaultGradleUserHome = path.resolve(await determineUserHome(), '.gradle')
+    // Use the default Gradle User Home if it already exists
+    if (fs.existsSync(defaultGradleUserHome)) {
+        core.info(`Gradle User Home already exists at ${defaultGradleUserHome}`)
+        return defaultGradleUserHome
+    }
+
+    // Switch Gradle User Home to faster 'D:' drive if possible
+    if (os.platform() === 'win32' && defaultGradleUserHome.startsWith('C:\\') && fs.existsSync('D:\\a\\')) {
+        const fasterGradleUserHome = 'D:\\a\\.gradle'
+        core.info(`Setting GRADLE_USER_HOME to ${fasterGradleUserHome} to leverage (potentially) faster drive.`)
+        core.exportVariable('GRADLE_USER_HOME', fasterGradleUserHome)
+        return fasterGradleUserHome
+    }
+
+    return defaultGradleUserHome
 }
 
 /**