[ZEPPELIN-1189] Get note revision websocket api

zeppelin-server/src/main/java/org/apache/zeppelin/socket/NotebookServer.java

@@ -45,6 +45,7 @@
 import org.apache.zeppelin.interpreter.InterpreterSetting;
 import org.apache.zeppelin.interpreter.remote.RemoteInterpreterProcessListener;
 import org.apache.zeppelin.notebook.*;
+import org.apache.zeppelin.notebook.repo.NotebookRepo.Revision;
 import org.apache.zeppelin.notebook.socket.Message;
 import org.apache.zeppelin.notebook.socket.Message.OP;
 import org.apache.zeppelin.scheduler.Job;
@@ -220,6 +221,9 @@ public void onMessage(NotebookSocket conn, String msg) {
           case CHECKPOINT_NOTEBOOK:
             checkpointNotebook(conn, notebook, messagereceived);
             break;
+          case NOTE_REVISION:
+            getNoteRevision(conn, notebook, messagereceived);
+            break;
           case LIST_NOTEBOOK_JOBS:
             unicastNotebookJobInfo(conn, messagereceived);
             break;
@@ -1129,6 +1133,18 @@ private void checkpointNotebook(NotebookSocket conn, Notebook notebook,
     notebook.checkpointNote(noteId, commitMessage, subject);
   }
 
+  private void getNoteRevision(NotebookSocket conn, Notebook notebook, Message fromMessage)
+      throws IOException {
+    String noteId = (String) fromMessage.get("noteId");
+    Revision revision = (Revision) fromMessage.get("revision");
+    AuthenticationInfo subject = new AuthenticationInfo(fromMessage.principal);
+    Note revisionNote = notebook.getNoteRevision(noteId, revision, subject);
+    conn.send(serializeMessage(new Message(OP.NOTE_REVISION)
+        .put("noteId", noteId)
+        .put("revisionId", revision)
+        .put("data", revisionNote)));
+  }
+
   /**
    * This callback is for the paragraph that runs on ZeppelinServer
    * @param noteId

zeppelin-web/src/app/notebook/notebook.controller.js

@@ -175,6 +175,12 @@ angular.module('zeppelinWebApp').controller('NotebookCtrl', function($scope, $ro
     document.getElementById('note.checkpoint.message').value = '';
   };
 
+  // receive certain revision of note
+  $scope.$on('noteRevision', function(event, data) {
+    console.log('received note revision %o', data);
+    //TODO(xxx): render it
+  });
+
   $scope.runNote = function() {
     BootstrapDialog.confirm({
       closable: true,

zeppelin-web/src/components/websocketEvents/websocketEvents.factory.js

@@ -109,6 +109,8 @@ angular.module('zeppelinWebApp').factory('websocketEvents',
       $rootScope.$broadcast('appLoad', data);
     } else if (op === 'APP_STATUS_CHANGE') {
       $rootScope.$broadcast('appStatusChange', data);
+    } else if (op === 'NOTE_REVISION') {
+      $rootScope.$broadcast('noteRevision', data);
     }
   });
 

zeppelin-web/src/components/websocketEvents/websocketMsg.service.js

@@ -161,6 +161,16 @@ angular.module('zeppelinWebApp').service('websocketMsgSrv', function($rootScope,
       });
     },
 
+    getNoteRevision: function(noteId, revisionId) {
+      websocketEvents.sendNewEvent({
+        op: 'NOTE_REVISION',
+        data: {
+          noteId: noteId,
+          revisionId: revisionId
+        }
+      });
+    },
+
     isConnected: function() {
       return websocketEvents.isConnected();
     },

zeppelin-zengine/src/main/java/org/apache/zeppelin/notebook/Notebook.java

@@ -55,6 +55,7 @@
 import org.apache.zeppelin.interpreter.InterpreterSetting;
 import org.apache.zeppelin.interpreter.remote.RemoteAngularObjectRegistry;
 import org.apache.zeppelin.notebook.repo.NotebookRepo;
+import org.apache.zeppelin.notebook.repo.NotebookRepo.Revision;
 import org.apache.zeppelin.notebook.repo.NotebookRepoSync;
 import org.apache.zeppelin.resource.ResourcePoolUtils;
 import org.apache.zeppelin.scheduler.Job;
@@ -357,6 +358,11 @@ public void checkpointNote(String noteId, String checkpointMessage, Authenticati
     notebookRepo.checkpoint(noteId, checkpointMessage, subject);
   }
 
+  public Note getNoteRevision(String noteId, Revision revision, AuthenticationInfo subject)
+      throws IOException {
+    return notebookRepo.get(noteId, revision, subject);
+  }
+
   @SuppressWarnings("rawtypes")
   private Note loadNoteFromRepo(String id, AuthenticationInfo subject) {
     Note note = null;

zeppelin-zengine/src/main/java/org/apache/zeppelin/notebook/repo/NotebookRepoSync.java

@@ -354,9 +354,14 @@ public Revision checkpoint(String noteId, String checkpointMsg, AuthenticationIn
   }
 
   @Override
-  public Note get(String noteId, Revision rev, AuthenticationInfo subject) throws IOException {
-    // Auto-generated method stub
-    return null;
+  public Note get(String noteId, Revision rev, AuthenticationInfo subject) {
+    Note revisionNote = null;
+    try {
+      revisionNote = getRepo(0).get(noteId, rev, subject);
+    } catch (IOException e) {
+      LOG.error("Failed to get revision {} of note {}", rev.id, noteId, e);
+    }
+    return revisionNote;
   }
 
   @Override

zeppelin-zengine/src/main/java/org/apache/zeppelin/notebook/socket/Message.java

@@ -114,6 +114,9 @@ public static enum OP {
     CHECKPOINT_NOTEBOOK,    // [c-s] checkpoint notebook to storage repository
                             // @param noteId
                             // @param checkpointName
+    NOTE_REVISION,          // [c-s] get certain revision of note
+                            // @param noteId
+                            // @param revisionId
 
     APP_APPEND_OUTPUT,      // [s-c] append output
     APP_UPDATE_OUTPUT,      // [s-c] update (replace) output