CHE-6063. Improve mechanism of handling file watcher 'MODIFIED' events

Signed-off-by: Roman Nikitenko <rnikiten@redhat.com>

Author: RomanNikitenko

ide/che-core-ide-app/src/main/java/org/eclipse/che/ide/editor/synchronization/EditorGroupSynchronizationImpl.java

@@ -10,6 +10,7 @@
  */
 package org.eclipse.che.ide.editor.synchronization;
 
+import static com.google.common.base.Strings.isNullOrEmpty;
 import static org.eclipse.che.ide.api.notification.StatusNotification.DisplayMode.EMERGE_MODE;
 import static org.eclipse.che.ide.api.notification.StatusNotification.DisplayMode.NOT_EMERGE_MODE;
 import static org.eclipse.che.ide.api.notification.StatusNotification.Status.FAIL;
@@ -144,7 +145,7 @@ public void onDocumentChanged(DocumentChangedEvent event) {
   }
 
   @Override
-  public void onFileContentUpdate(final FileContentUpdateEvent event) {
+  public void onFileContentUpdate(FileContentUpdateEvent event) {
     if (synchronizedEditors.keySet().isEmpty()) {
       return;
     }
@@ -159,13 +160,54 @@ public void onFileContentUpdate(final FileContentUpdateEvent event) {
       return;
     }
 
+    if (!(virtualFile instanceof File)) {
+      updateContent(virtualFile, false);
+      return;
+    }
+
+    File file = (File) virtualFile;
+
+    String eventModificationStamp = event.getModificationStamp();
+    String currentModificationStamp = file.getModificationStamp();
+    if (isNullOrEmpty(currentModificationStamp) || isNullOrEmpty(eventModificationStamp)) {
+      updateContent(virtualFile, false);
+      return;
+    }
+
+    if (!Objects.equals(eventModificationStamp, currentModificationStamp)) {
+      updateContent(virtualFile, true);
+    }
+  }
+
+  private void updateContent(VirtualFile virtualFile, boolean externalOperation) {
+    final DocumentHandle documentHandle = getDocumentHandleFor(groupLeaderEditor);
+    if (documentHandle == null) {
+      return;
+    }
+
     documentStorage.getDocument(
         virtualFile,
         new DocumentStorage.DocumentCallback() {
 
           @Override
-          public void onDocumentReceived(final String content) {
-            updateContent(content, event.getModificationStamp(), virtualFile);
+          public void onDocumentReceived(String newContent) {
+            Document document = documentHandle.getDocument();
+
+            String oldContent = document.getContents();
+            if (Objects.equals(newContent, oldContent)) {
+              return;
+            }
+
+            TextPosition cursorPosition = document.getCursorPosition();
+            replaceContent(document, newContent, oldContent, cursorPosition);
+
+            if (externalOperation) {
+              notificationManager.notify(
+                  "External operation",
+                  "File '" + virtualFile.getName() + "' is updated",
+                  SUCCESS,
+                  NOT_EMERGE_MODE);
+            }
           }
 
           @Override
@@ -179,44 +221,6 @@ public void onDocumentLoadFailure(final Throwable caught) {
         });
   }
 
-  private void updateContent(
-      String newContent, String eventModificationStamp, VirtualFile virtualFile) {
-    final DocumentHandle documentHandle = getDocumentHandleFor(groupLeaderEditor);
-    if (documentHandle == null) {
-      return;
-    }
-
-    final Document document = documentHandle.getDocument();
-    final String oldContent = document.getContents();
-    if (Objects.equals(newContent, oldContent)) {
-      return;
-    }
-
-    final TextPosition cursorPosition = document.getCursorPosition();
-    if (!(virtualFile instanceof File)) {
-      replaceContent(document, newContent, oldContent, cursorPosition);
-      return;
-    }
-
-    final File file = (File) virtualFile;
-    final String currentStamp = file.getModificationStamp();
-
-    if (eventModificationStamp == null) {
-      replaceContent(document, newContent, oldContent, cursorPosition);
-      return;
-    }
-
-    if (!Objects.equals(eventModificationStamp, currentStamp)) {
-      replaceContent(document, newContent, oldContent, cursorPosition);
-
-      notificationManager.notify(
-          "External operation",
-          "File '" + file.getName() + "' is updated",
-          SUCCESS,
-          NOT_EMERGE_MODE);
-    }
-  }
-
   private void replaceContent(
       Document document, String newContent, String oldContent, TextPosition cursorPosition) {
     document.replace(0, oldContent.length(), newContent);

ide/che-core-ide-app/src/test/java/org/eclipse/che/ide/editor/synchronization/EditorGroupSynchronizationImplTest.java

@@ -158,6 +158,7 @@ public void shouldNotifyAboutExternalOperationAtUpdateContentWhenStampIsDifferen
     reset(documentEventBus);
     when(fileContentUpdateEvent.getFilePath()).thenReturn(FILE_LOCATION);
     when(fileContentUpdateEvent.getModificationStamp()).thenReturn("some stamp");
+    when(((File) virtualFile).getModificationStamp()).thenReturn("current modification stamp");
 
     editorGroupSynchronization.onFileContentUpdate(fileContentUpdateEvent);
 

wsagent/che-core-api-project/src/main/java/org/eclipse/che/api/vfs/impl/file/LocalVirtualFileSystem.java

@@ -616,8 +616,8 @@ private File createTempIoFile(VirtualFile parent, String prefix, String suffix)
 
   private void doUpdateContent(LocalVirtualFile virtualFile, InputStream content)
       throws ServerException {
-    try (FileOutputStream fileOut = new FileOutputStream(virtualFile.toIoFile())) {
-      ByteStreams.copy(content, fileOut);
+    try {
+      Files.write(ByteStreams.toByteArray(content), virtualFile.toIoFile());
     } catch (IOException e) {
       String errorMessage = String.format("Unable set content of '%s'", virtualFile.getPath());
       LOG.error(errorMessage + "\n" + e.getMessage(), e);