[DownloadBuildArtifactsV0] Respect "Parallelization limit" input

Tasks/DownloadBuildArtifactsV0/download_helper.ts

@@ -2,15 +2,6 @@ import { debug, loc } from 'azure-pipelines-task-lib/task';
 import { ArtifactDownloadTicket, ItemType, TicketState } from 'artifact-engine/Models';
 import { getFileSizeInBytes } from './file_helper';
 
-/**
- * Just a Promise wrapper for setTimeout function
- * @param {number} interval - timeout interval in milliseconds
- */
-export function timeoutPromise(interval: number): Promise<{}> {
-    debug(`Wait for ${interval} milliseconds`);
-    return new Promise(resolve => setTimeout(resolve, interval));
-}
-
 /**
  * This function checks a result of artifact download
  * @param  {Array<ArtifactDownloadTicket>} downloadTickets
@@ -96,3 +87,61 @@ function isItemCorrupted(ticket: ArtifactDownloadTicket): boolean {
 
     return isCorrupted;
 }
+
+/**
+ * This function resolves the value for the `parallelProcessingLimit` option of `ArtifactEngine`
+ *
+ * Earlier the only way to set parallelProcessingLimit in the task
+ * was by declaring the `release.artifact.download.parallellimit` variable.
+ *
+ * To maintain backward compatibility we will use the following strategy:
+ *
+ * Firstly, investigate the `release.artifact.download.parallellimit` variable.
+ * If everything is okay with this variable, the task will use the value from this variable.
+ *
+ * Secondly, investigate the `Parallelization limit` input of the task.
+ * If everything is okay with the value in the related task's input, the task will use the value from this input.
+ *
+ * If validation failed for both cases the function will return the `defaultLimit` for the `parallelProcessingLimit` option.
+ *
+ * @param {string} artifactDownloadLimit - value of `release.artifact.download.parallellimit` variable
+ * @param {string} taskLimit - value of `Parallelization limit` task input
+ * @param {number} defaultLimit - the default value that will be returned if `artifactDownloadLimit` and `taskLimit` contain invalid values.
+ * @returns {number} - parallel processing limit
+ */
+export function resolveParallelProcessingLimit(artifactDownloadLimit: string, taskLimit: string, defaultLimit: number): number {
+    debug(`Checking value of the "release.artifact.download.parallellimit" variable - ${artifactDownloadLimit}`);
+    const artifactDownloadParallelLimit: number = Number(artifactDownloadLimit);
+    if (isParallelProcessingLimitCorrect(artifactDownloadParallelLimit)) {
+        return artifactDownloadParallelLimit;
+    }
+
+    debug(`Checking value of the "Parallelization limit" input - ${taskLimit}`);
+    const taskInputParallelLimit: number = Number(taskLimit);
+    if (isParallelProcessingLimitCorrect(taskInputParallelLimit)) {
+        return taskInputParallelLimit;
+    }
+
+    debug(`The parallelization limit is set to default value - ${defaultLimit}`);
+    return defaultLimit;
+}
+
+/**
+ * This function checks the input value for the `parallelProcessingLimit` option of `ArtifactEngine`
+ *
+ * The parallel processing limit must be a number greater than 0.
+ *
+ * @param {number} limit - value of parallel processing limit
+ * @returns {boolean} true if parallel processing limit is correct, false otherwise.
+ */
+function isParallelProcessingLimitCorrect(limit: number): boolean {
+    const isCorrect: boolean = (!isNaN(limit) && limit > 0);
+
+    if (isCorrect) {
+        debug(`The value is correct, the parallelization limit is set to ${limit}`);
+    } else {
+        debug(`The value is incorrect ${limit}`);
+    }
+
+    return isCorrect;
+}

Tasks/DownloadBuildArtifactsV0/main.ts

@@ -17,11 +17,14 @@ import { DownloadHandlerContainer } from './DownloadHandlers/DownloadHandlerCont
 import { DownloadHandlerContainerZip } from './DownloadHandlers/DownloadHandlerContainerZip';
 import { DownloadHandlerFilePath } from './DownloadHandlers/DownloadHandlerFilePath';
 
+import { resolveParallelProcessingLimit } from './download_helper';
+
 var taskJson = require('./task.json');
 
 tl.setResourcePath(path.join(__dirname, 'task.json'));
 
 const area: string = 'DownloadBuildArtifacts';
+const DefaultParallelProcessingLimit: number = 8;
 
 function getDefaultProps() {
     var hostType = (tl.getVariable('SYSTEM.HOSTTYPE') || "").toLowerCase();
@@ -73,7 +76,7 @@ async function main(): Promise<void> {
         var buildId: number = null;
         var buildVersionToDownload: string = tl.getInput("buildVersionToDownload", false);
         var allowPartiallySucceededBuilds: boolean = tl.getBoolInput("allowPartiallySucceededBuilds", false);
-        var branchName: string = tl.getInput("branchName", false);;
+        var branchName: string = tl.getInput("branchName", false);
         var downloadPath: string = tl.getInput("downloadPath", true);
         var downloadType: string = tl.getInput("downloadType", true);
         var tagFiltersInput: string = tl.getInput("tags", false);
@@ -253,7 +256,7 @@ async function main(): Promise<void> {
         if (artifacts) {
             var downloadPromises: Array<Promise<any>> = [];
             artifacts.forEach(async function (artifact, index, artifacts) {
-                let downloaderOptions = configureDownloaderOptions();
+                const downloaderOptions: engine.ArtifactEngineOptions = configureDownloaderOptions();
 
                 const config: IBaseHandlerConfig = {
                     artifactInfo: artifact,
@@ -372,11 +375,16 @@ function getRetryIntervalInSeconds(retryCount: number): number {
 }
 
 function configureDownloaderOptions(): engine.ArtifactEngineOptions {
-    var downloaderOptions = new engine.ArtifactEngineOptions();
-    downloaderOptions.itemPattern = tl.getInput('itemPattern', false) || "**";
-    downloaderOptions.parallelProcessingLimit = +tl.getVariable("release.artifact.download.parallellimit") || 8;
-    var debugMode = tl.getVariable('System.Debug');
-    downloaderOptions.verbose = debugMode ? debugMode.toLowerCase() != 'false' : false;
+    const downloaderOptions: engine.ArtifactEngineOptions = new engine.ArtifactEngineOptions();
+
+    const debugMode: string = tl.getVariable('System.Debug');
+    downloaderOptions.verbose = debugMode ? debugMode.toLowerCase() !== 'false' : false;
+
+    const artifactDownloadLimit: string = tl.getVariable('release.artifact.download.parallellimit');
+    const taskInputParallelLimit: string = tl.getInput('parallelizationLimit', false);
+    downloaderOptions.parallelProcessingLimit = resolveParallelProcessingLimit(artifactDownloadLimit, taskInputParallelLimit, DefaultParallelProcessingLimit);
+
+    downloaderOptions.itemPattern = tl.getInput('itemPattern', false) || '**';
 
     return downloaderOptions;
 }

Tasks/DownloadBuildArtifactsV0/task.json

@@ -9,7 +9,7 @@
     "author": "Microsoft Corporation",
     "version": {
         "Major": 0,
-        "Minor": 183,
+        "Minor": 184,
         "Patch": 0
     },
     "groups": [

Tasks/DownloadBuildArtifactsV0/task.loc.json

@@ -9,7 +9,7 @@
   "author": "Microsoft Corporation",
   "version": {
     "Major": 0,
-    "Minor": 183,
+    "Minor": 184,
     "Patch": 0
   },
   "groups": [