ZEPPELIN-143: WIP - very basic sketch of GitNotebookRepo

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

@@ -0,0 +1,82 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.zeppelin.notebook.repo;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.apache.zeppelin.conf.ZeppelinConfiguration;
+import org.apache.zeppelin.notebook.Note;
+
+/**
+ * NotebookRepo that hosts all the notebook FS in a single Git repo
+ *
+ * This impl intended to be simple and straightforward:
+ *   - does not handle branches
+ *   - only basic git, no Github push\pull yet
+ * 
+ * 
+ * TODO(bzz): describe config
+ *  GIT_URL remote
+ *  auth credentials
+ */
+public class GitNotebookRepo extends VFSNotebookRepo implements NotebookRepoVersioned {
+
+  // I. First usefull case: 
+  //   start \w repo + tutorial notebook
+  //   all modifications results in a commit
+  
+  // II. Next case:
+  //   start \wo .git
+  //   create one
+  //   add existing notebooks
+  //   ..and then I...
+
+  // III. Next case:
+  //   start \w repo 
+  //   show history
+  //   user can switch to REV in read-only
+  
+  public GitNotebookRepo(ZeppelinConfiguration conf) throws IOException {
+    super(conf);
+
+    //TODO(bzz):
+    // - check that ./notebooks/.git exists
+    // - git init
+    // - setup EGit
+  }
+
+  @Override
+  public void save(Note note) throws IOException {
+    super.save(note);
+    //TODO(alex): if (git diff) { git add; git commit }
+  }
+
+  @Override
+  public Note get(String noteId, String rev) throws IOException {
+    //TODO(alex): something instead of 'git checkout rev', which will not change-the-world
+    return super.get(noteId);
+  }
+
+  @Override
+  public List<String> history(String noteId) {
+    //TODO(alex): git logs
+    return null;
+  }
+
+}

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

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+package org.apache.zeppelin.notebook.repo;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.apache.zeppelin.notebook.Note;
+
+/**
+ * Notebook repository w/ versions
+ */
+public interface NotebookRepoVersioned extends NotebookRepo {
+  
+  /**
+   * Get particular revision of the Notebooks
+   * 
+   * @param noteId Id of the Notebook
+   * @param rev revision of the Notebook
+   * @return a Notebook
+   * @throws IOException 
+   */
+  public abstract Note get(String noteId, String rev) throws IOException;
+
+  /**
+   * List of revisions of the given Notebook
+   * 
+   * @param noteId id of the Notebook
+   * @return list of revisions
+   */
+  public abstract List<String> history(String noteId);
+}