[WIP] Add opt-in Usage Reporter (call-home) for the CloudStack project

engine/schema/src/main/java/com/cloud/upgrade/dao/VersionDao.java

@@ -16,11 +16,22 @@
 // under the License.
 package com.cloud.upgrade.dao;
 
+import java.util.List;
+
 import com.cloud.upgrade.dao.VersionVO.Step;
 import com.cloud.utils.db.GenericDao;
 
 public interface VersionDao extends GenericDao<VersionVO, Long> {
     VersionVO findByVersion(String version, Step step);
 
     String getCurrentVersion();
+
+    List<VersionVO> getAllVersions();
+
+    /**
+     * @return the oldest row of the version table, which records the version the
+     *         database was originally created with and when, or null if the table
+     *         is empty
+     */
+    VersionVO getInitialVersion();
 }

engine/schema/src/main/java/com/cloud/upgrade/dao/VersionDaoImpl.java

@@ -150,4 +150,22 @@ public String getCurrentVersion() {
         }
 
     }
+
+    @Override
+    @DB
+    public List<VersionVO> getAllVersions() {
+        SearchCriteria<VersionVO> sc = AllFieldsSearch.create();
+        sc.setParameters("step", Step.Complete);
+
+        return listBy(sc);
+    }
+
+    @Override
+    @DB
+    public VersionVO getInitialVersion() {
+        final Filter filter = new Filter(VersionVO.class, "id", true, 0L, 1L);
+        final List<VersionVO> versions = listAll(filter);
+
+        return versions.isEmpty() ? null : versions.get(0);
+    }
 }

server/src/main/java/org/apache/cloudstack/report/AtomicGsonAdapter.java

@@ -0,0 +1,48 @@
+// 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.cloudstack.report;
+
+import com.google.gson.TypeAdapter;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonWriter;
+import com.google.common.util.concurrent.AtomicLongMap;
+import java.util.Map;
+import java.io.IOException;
+
+public class AtomicGsonAdapter extends TypeAdapter<AtomicLongMap> {
+
+    public AtomicLongMap<Object> read(JsonReader reader) throws IOException {
+        reader.nextNull();
+        return null;
+    }
+
+    public void write(JsonWriter writer, AtomicLongMap value) throws IOException {
+        if (value == null) {
+            writer.nullValue();
+            return;
+        }
+
+        @SuppressWarnings("unchecked")
+        Map<Object, Long> map = value.asMap();
+
+        writer.beginObject();
+        for (Map.Entry<Object, Long> entry : map.entrySet()) {
+            writer.name(String.valueOf(entry.getKey())).value(entry.getValue());
+        }
+        writer.endObject();
+    }
+}