File download safe multiple download at the same time, prevent images from the...

File download safe multiple download at the same time, prevent images from the same url to be downloaded several times

Runtime/Scripts/WorldAnalysisARFoundationHelper.cs

@@ -18,13 +18,14 @@ public class WorldAnalysisARFoundationHelper
         string fileName = "";
         #if UNITY_EDITOR
             string folder = Application.streamingAssetsPath;
-        #else 
+#else
             string folder = Application.persistentDataPath;
-        #endif
-        
+#endif
+
+        string uniqueFileName = "/Temp"+ System.Guid.NewGuid()+".data";
         using (var client = new WebClient())
         {
-            await client.DownloadFileTaskAsync(toLoad, folder + "/Temp.data");
+            await client.DownloadFileTaskAsync(toLoad, folder + uniqueFileName);
             string header_contentDisposition = client.ResponseHeaders["content-disposition"];
             if (header_contentDisposition == null)
             {
@@ -40,7 +41,7 @@ public class WorldAnalysisARFoundationHelper
             {
                 File.Delete(filePath);
             }
-            File.Move(folder + "/Temp.data", filePath);
+            File.Move(folder + uniqueFileName, filePath);
         }
         return new KeyValuePair<string, string>(filePath , fileName);
     }

Runtime/Scripts/WorldAnalysisARFoundationModuleImage.cs

@@ -17,7 +17,11 @@ public class WorldAnalysisARFoundationModuleImage : WorldAnalysisARFoundationMod
     /// <summary>
     /// Name of all images that have been added to the library
     /// </summary>
-    private List<string> m_trackedImageInLibrary; 
+    private List<string> m_trackedImageInLibrary;
+    /// <summary>
+    /// All url of images that have allready been downloaded
+    /// </summary>
+    private List<string> m_allDownloadedImages;
     /// <summary>
     /// List of tracked images with tracking infos
     /// </summary>
@@ -35,6 +39,7 @@ public class WorldAnalysisARFoundationModuleImage : WorldAnalysisARFoundationMod
         XROrigin origin = UnityEngine.Object.FindAnyObjectByType<XROrigin>();
         m_trackedImageManager = origin.gameObject.AddComponent<ARTrackedImageManager>();
         m_trackedImageInLibrary = new List<string>();
+        m_allDownloadedImages = new List<string>();
         m_trackedImageManager.trackedImagePrefab = (GameObject)Resources.Load("ARFImageTrackingPrefab");
         m_trackedImageManager.trackedImagesChanged += OnTrackedImagesChanged;
     }
@@ -172,8 +177,12 @@ public class WorldAnalysisARFoundationModuleImage : WorldAnalysisARFoundationMod
 
         if (!found)
         {
-            // Here we don't check if url exists and still return true: could be improve
-            LoadTextureFromURL(url, fileName, imageWidthInMeters);
+            // Do not download the same image twice
+            if (!m_allDownloadedImages.Contains(url))
+            {
+                // Here we don't check if url exists and still return true: could be improve
+                LoadTextureFromURL(url, fileName, imageWidthInMeters);
+            }
         }
         else 
         {
@@ -206,6 +215,7 @@ public class WorldAnalysisARFoundationModuleImage : WorldAnalysisARFoundationMod
     public async void LoadTextureFromURL(string url, string fileName, float imageWidthInMeters)
     {
         Debug.Log("Download image from url "+ url);
+        m_allDownloadedImages.Add(url);
         KeyValuePair<string , string> downloaded = await WorldAnalysisARFoundationHelper.DownloadFileHTTP(url);
         LoadTextureFromMemory(downloaded.Key, fileName, imageWidthInMeters);
     }