[HWMETRICS-52] separate interface and impl classes

task-queue/src/main/java/org/hawkular/metrics/tasks/DateTimeService.java

@@ -27,7 +27,7 @@
 /**
  * @author jsanda
  */
-class DateTimeService {
+public class DateTimeService {
 
     /**
      * @return A DateTime object rounded down to the start of the current hour. For example, if the current time is

task-queue/src/main/java/org/hawkular/metrics/tasks/Task.java → task-queue/src/main/java/org/hawkular/metrics/tasks/api/Task.java

@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.hawkular.metrics.tasks;
+package org.hawkular.metrics.tasks.api;
 
 import java.util.Set;
 
@@ -33,14 +33,14 @@ public interface Task {
     TaskType getTaskType();
 
     /**
-     * This is a key or identifier of the entity or thing associated with any data produced by the task. Consider
-     * aggregating metrics or events as an example. Let's say there is a task for computing a 5 minute rollup from raw
+     * This is a key or identifier of the time series that is associated with the task. Consider aggregating metrics or
+     * events as an example. Let's say there is a task for computing a 5 minute rollup from raw
      * data. This property should be the key or identifier of the 5 minute rollup time series.
      */
     String getTarget();
 
     /**
-     * The keys or identifiers of the entities associated with the source data being operated on. There can be one or
+     * The keys or identifiers of the time series associated with the source data being operated on. There can be one or
      * more sources. Consider aggregating metrics or events as an example. There is a task for computing a 5 minute
      * rollup from raw data. This property identifies the time series of the raw data to be aggregated.
      */

task-queue/src/main/java/org/hawkular/metrics/tasks/TaskExecutionException.java → task-queue/src/main/java/org/hawkular/metrics/tasks/api/TaskExecutionException.java

@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.hawkular.metrics.tasks;
+package org.hawkular.metrics.tasks.api;
 
 /**
  * @author jsanda

task-queue/src/main/java/org/hawkular/metrics/tasks/api/TaskService.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2014-2015 Red Hat, Inc. and/or its affiliates
+ * and other contributors as indicated by the @author tags.
+ *
+ * Licensed 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.hawkular.metrics.tasks.api;
+
+import com.google.common.util.concurrent.ListenableFuture;
+import org.joda.time.DateTime;
+
+/**
+ * @author jsanda
+ */
+public interface TaskService {
+    /**
+     * Starts the scheduler. Task execution can be scheduled every second or every minute. Task execution for a
+     * particular time slice will run at the end of said time slice or later but never sooner.
+     *
+     * TODO log warning if scheduling falls behind
+     */
+    void start();
+
+    void shutdown();
+
+    ListenableFuture<Task> scheduleTask(DateTime time, Task task);
+}

task-queue/src/main/java/org/hawkular/metrics/tasks/TaskType.java → task-queue/src/main/java/org/hawkular/metrics/tasks/api/TaskType.java

@@ -14,13 +14,20 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.hawkular.metrics.tasks;
+package org.hawkular.metrics.tasks.api;
 
 import java.util.Objects;
 import java.util.function.Consumer;
 import java.util.function.Supplier;
 
+import org.hawkular.metrics.tasks.impl.TaskImpl;
+
 /**
+ * Tasks are grouped by type, and execution order is also determined by type. If there are types A, B, C, then for
+ * a given time slice all tasks of type A are executed followed by tasks of type B and finally tasks of type C are
+ * executed. The task type specifies the granularity of partitioning of tasks in the database. It also provides a
+ * factory function that produces a function to execute tasks.
+ *
  * @author jsanda
  */
 public class TaskType {
@@ -33,6 +40,9 @@ public class TaskType {
 
     private int segmentOffsets;
 
+    /**
+     * The task type name which must be unique among task types.
+     */
     public String getName() {
         return name;
     }
@@ -42,6 +52,9 @@ public TaskType setName(String name) {
         return this;
     }
 
+    /**
+     * A function that produces functions that carry out task execution.
+     */
     public Supplier<Consumer<Task>> getFactory() {
         return factory;
     }
@@ -51,6 +64,10 @@ public TaskType setFactory(Supplier<Consumer<Task>> factory) {
         return this;
     }
 
+    /**
+     * The number of partitions in the database to use for storing tasks. The segment is determined by,
+     * <code>task.target.hashCode() % segments</code>
+     */
     public int getSegments() {
         return segments;
     }
@@ -60,6 +77,14 @@ public TaskType setSegments(int segments) {
         return this;
     }
 
+    /**
+     * Tasks are associated with leases. A client needs to acquire a lease before it can execute the tasks associated
+     * with the lease. This property specifies how many tasks in terms of segments are associated with a lease. Let's
+     * say that we have 100 segments and 10 segment offsets. This means that there are 10 task segments per lease.
+     * When a client acquires a lease, the client will then execute the tasks in each of those segments.
+     * <br/><br/>
+     * TODO Come up with a more descriptive name
+     */
     public int getSegmentOffsets() {
         return segmentOffsets;
     }
@@ -69,6 +94,15 @@ public TaskType setSegmentOffsets(int segmentOffsets) {
         return this;
     }
 
+    /**
+     * A factory method for creating tasks of this type.
+     *
+     * @param target Identifier or key of the entity or time series associated with the task
+     * @param source Identifiers or keys of the time series that provide input data for the task
+     * @param interval Specifies the frequency of execution in minutes
+     * @param window Specifies the amount of data to include in minutes
+     * @return A {@link Task}
+     */
     public Task createTask(String target, String source, int interval, int window) {
         return new TaskImpl(this, null, target, source, interval, window);
     }

task-queue/src/main/java/org/hawkular/metrics/tasks/Lease.java → task-queue/src/main/java/org/hawkular/metrics/tasks/impl/Lease.java

@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.hawkular.metrics.tasks;
+package org.hawkular.metrics.tasks.impl;
 
 import java.util.Objects;
 

task-queue/src/main/java/org/hawkular/metrics/tasks/LeaseManager.java → task-queue/src/main/java/org/hawkular/metrics/tasks/impl/LeaseManager.java

@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.hawkular.metrics.tasks;
+package org.hawkular.metrics.tasks.impl;
 
 import static java.util.stream.Collectors.toList;
 

task-queue/src/main/java/org/hawkular/metrics/tasks/Queries.java → task-queue/src/main/java/org/hawkular/metrics/tasks/impl/Queries.java

@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.hawkular.metrics.tasks;
+package org.hawkular.metrics.tasks.impl;
 
 import com.datastax.driver.core.PreparedStatement;
 import com.datastax.driver.core.Session;

task-queue/src/main/java/org/hawkular/metrics/tasks/TaskContainer.java → task-queue/src/main/java/org/hawkular/metrics/tasks/impl/TaskContainer.java

@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.hawkular.metrics.tasks;
+package org.hawkular.metrics.tasks.impl;
 
 import java.util.Iterator;
 import java.util.Objects;
@@ -25,6 +25,8 @@
 import java.util.TreeSet;
 import java.util.function.Consumer;
 
+import org.hawkular.metrics.tasks.api.TaskType;
+import org.hawkular.metrics.tasks.api.Task;
 import org.joda.time.DateTime;
 import org.joda.time.Duration;
 

task-queue/src/main/java/org/hawkular/metrics/tasks/TaskImpl.java → task-queue/src/main/java/org/hawkular/metrics/tasks/impl/TaskImpl.java

@@ -14,14 +14,16 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.hawkular.metrics.tasks;
+package org.hawkular.metrics.tasks.impl;
 
 import static org.joda.time.Duration.standardMinutes;
 
 import java.util.Objects;
 import java.util.Set;
 
 import com.google.common.collect.ImmutableSet;
+import org.hawkular.metrics.tasks.api.TaskType;
+import org.hawkular.metrics.tasks.api.Task;
 import org.joda.time.DateTime;
 import org.joda.time.Duration;
 

task-queue/src/main/java/org/hawkular/metrics/tasks/TaskService.java → task-queue/src/main/java/org/hawkular/metrics/tasks/impl/TaskServiceImpl.java

@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.hawkular.metrics.tasks;
+package org.hawkular.metrics.tasks.impl;
 
 import static java.util.stream.Collectors.toList;
 import static java.util.stream.Collectors.toSet;
@@ -48,6 +48,10 @@
 import com.google.common.util.concurrent.ListeningExecutorService;
 import com.google.common.util.concurrent.MoreExecutors;
 import com.google.common.util.concurrent.Uninterruptibles;
+import org.hawkular.metrics.tasks.DateTimeService;
+import org.hawkular.metrics.tasks.api.TaskExecutionException;
+import org.hawkular.metrics.tasks.api.Task;
+import org.hawkular.metrics.tasks.api.TaskType;
 import org.joda.time.DateTime;
 import org.joda.time.Duration;
 import org.slf4j.Logger;
@@ -56,9 +60,9 @@
 /**
  * @author jsanda
  */
-public class TaskService {
+public class TaskServiceImpl implements org.hawkular.metrics.tasks.api.TaskService {
 
-    private static final Logger logger = LoggerFactory.getLogger(TaskService.class);
+    private static final Logger logger = LoggerFactory.getLogger(TaskServiceImpl.class);
 
     private Duration timeSliceDuration;
 
@@ -95,7 +99,7 @@ public class TaskService {
 
     private TimeUnit tickerUnit = TimeUnit.MINUTES;
 
-    public TaskService(Session session, Queries queries, LeaseManager leaseManager, Duration timeSliceDuration,
+    public TaskServiceImpl(Session session, Queries queries, LeaseManager leaseManager, Duration timeSliceDuration,
             List<TaskType> taskTypes) {
         this.session = session;
         this.queries = queries;
@@ -114,12 +118,7 @@ void setTickerUnit(TimeUnit tickerUnit) {
         this.tickerUnit = tickerUnit;
     }
 
-    /**
-     * Starts the scheduler. Task execution can be scheduled every second or every minute. Task execution for a
-     * particular time slice will run at the end of said time slice or later but never sooner.
-     *
-     * TODO log warning if scheduling falls behind
-     */
+    @Override
     public void start() {
         Runnable runnable = () -> {
             DateTime timeSlice = dateTimeService.getTimeSlice(now(), timeSliceDuration);
@@ -128,6 +127,7 @@ public void start() {
         ticker.scheduleAtFixedRate(runnable, 0, 1, tickerUnit);
     }
 
+    @Override
     public void shutdown() {
 //        ticker.shutdownNow();
 //        scheduler.shutdownNow();
@@ -150,6 +150,7 @@ private TaskType findTaskType(String type) {
                 .orElseThrow(() -> new IllegalArgumentException(type + " is not a recognized task type"));
     }
 
+    @Override
     public ListenableFuture<Task> scheduleTask(DateTime time, Task task) {
         TaskType taskType = findTaskType(task.getTaskType().getName());
 

task-queue/src/test/java/org/hawkular/metrics/tasks/BaseTest.java

@@ -24,6 +24,7 @@
 import com.datastax.driver.core.Session;
 import com.google.common.util.concurrent.ListenableFuture;
 import com.google.common.util.concurrent.Uninterruptibles;
+import org.hawkular.metrics.tasks.impl.Queries;
 import org.testng.annotations.BeforeMethod;
 import org.testng.annotations.BeforeSuite;
 

task-queue/src/test/java/org/hawkular/metrics/tasks/LeaseManagerTest.java → task-queue/src/test/java/org/hawkular/metrics/tasks/impl/LeaseManagerTest.java

@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.hawkular.metrics.tasks;
+package org.hawkular.metrics.tasks.impl;
 
 import static org.joda.time.DateTime.now;
 import static org.testng.Assert.assertEquals;
@@ -26,6 +26,7 @@
 import com.datastax.driver.core.PreparedStatement;
 import com.google.common.collect.ImmutableList;
 import com.google.common.util.concurrent.ListenableFuture;
+import org.hawkular.metrics.tasks.BaseTest;
 import org.joda.time.DateTime;
 import org.joda.time.Minutes;
 import org.testng.annotations.BeforeClass;

task-queue/src/test/java/org/hawkular/metrics/tasks/TaskSchedulerTest.java → task-queue/src/test/java/org/hawkular/metrics/tasks/impl/TaskSchedulerTest.java

@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.hawkular.metrics.tasks;
+package org.hawkular.metrics.tasks.impl;
 
 import static java.util.Arrays.asList;
 import static org.joda.time.DateTime.now;
@@ -25,6 +25,8 @@
 import java.util.List;
 import java.util.concurrent.TimeUnit;
 
+import org.hawkular.metrics.tasks.BaseTest;
+import org.hawkular.metrics.tasks.api.TaskType;
 import org.joda.time.DateTime;
 import org.testng.annotations.BeforeClass;
 import org.testng.annotations.Test;
@@ -52,7 +54,8 @@ public void startScheduler() throws Exception {
                 dateTimeService.getTimeSlice(now().plusSeconds(2), standardSeconds(3))
         );
 
-        TaskService taskService = new TaskService(session, queries, leaseManager, standardSeconds(1), taskTypes) {
+        TaskServiceImpl taskService = new TaskServiceImpl(session, queries, leaseManager, standardSeconds(1),
+                taskTypes) {
             @Override
             public void executeTasks(DateTime timeSlice) {
                 actualTimeSlices.add(timeSlice);