Use Azure storage SDK to download cache (#497)

* Adds option to download using AzCopy

* Bump version number and add release notes

* Ensure we use at least v10

* Negate env var so it disables AzCopy

* Use Azure storage SDK to download cache

* Use same level of parallelism as AzCopy

* Fix naming of variable

* React to feedback

* Bump Node types to Node 12

* Make linter happy

* Pass options into restoreCache method

* Fix tests

* Restructure files and add tests

* Add method to get the default download and upload options

* Include breaking changes in RELEASES.md

Co-authored-by: Josh Gross <joshmgross@github.com>

packages/cache/src/options.ts

@@ -1,3 +1,5 @@
+import * as core from '@actions/core'
+
 /**
  * Options to control cache upload
  */
@@ -15,3 +17,93 @@ export interface UploadOptions {
    */
   uploadChunkSize?: number
 }
+
+/**
+ * Options to control cache download
+ */
+export interface DownloadOptions {
+  /**
+   * Indicates whether to use the Azure Blob SDK to download caches
+   * that are stored on Azure Blob Storage to improve reliability and
+   * performance
+   *
+   * @default true
+   */
+  useAzureSdk?: boolean
+
+  /**
+   * Number of parallel downloads (this option only applies when using
+   * the Azure SDK)
+   *
+   * @default 8
+   */
+  downloadConcurrency?: number
+
+  /**
+   * Maximum time for each download request, in milliseconds (this
+   * option only applies when using the Azure SDK)
+   *
+   * @default 30000
+   */
+  timeoutInMs?: number
+}
+
+/**
+ * Returns a copy of the upload options with defaults filled in.
+ *
+ * @param copy the original upload options
+ */
+export function getUploadOptions(copy?: UploadOptions): UploadOptions {
+  const result: UploadOptions = {
+    uploadConcurrency: 4,
+    uploadChunkSize: 32 * 1024 * 1024
+  }
+
+  if (copy) {
+    if (typeof copy.uploadConcurrency === 'number') {
+      result.uploadConcurrency = copy.uploadConcurrency
+    }
+
+    if (typeof copy.uploadChunkSize === 'number') {
+      result.uploadChunkSize = copy.uploadChunkSize
+    }
+  }
+
+  core.debug(`Upload concurrency: ${result.uploadConcurrency}`)
+  core.debug(`Upload chunk size: ${result.uploadChunkSize}`)
+
+  return result
+}
+
+/**
+ * Returns a copy of the download options with defaults filled in.
+ *
+ * @param copy the original download options
+ */
+export function getDownloadOptions(copy?: DownloadOptions): DownloadOptions {
+  const result: DownloadOptions = {
+    useAzureSdk: true,
+    downloadConcurrency: 8,
+    timeoutInMs: 30000
+  }
+
+  if (copy) {
+    if (typeof copy.useAzureSdk === 'boolean') {
+      result.useAzureSdk = copy.useAzureSdk
+    }
+
+    if (typeof copy.downloadConcurrency === 'number') {
+      result.downloadConcurrency = copy.downloadConcurrency
+    }
+
+    if (typeof copy.timeoutInMs === 'number') {
+      result.timeoutInMs = copy.timeoutInMs
+    }
+  }
+
+  core.debug(`Use Azure SDK: ${result.useAzureSdk}`)
+  core.debug(`Download concurrency: ${result.downloadConcurrency}`)
+  core.debug(`Request timeout (ms): ${result.timeoutInMs}`)
+
+  return result
+}