feat: findTasksStream

Author: Sciator

client/src/main/java/com/influxdb/client/TasksApi.java

@@ -23,6 +23,7 @@
 
 import java.time.OffsetDateTime;
 import java.util.List;
+import java.util.stream.Stream;
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.ThreadSafe;
@@ -275,6 +276,15 @@ List<Task> findTasks(@Nullable final String afterID,
     @Nonnull
     List<Task> findTasks(@Nonnull final TasksQuery query);
 
+    /**
+     * Query tasks, automaticaly paged by given limit (default 100).
+     *
+     * @param query query params for task
+     * @return A list of tasks
+     */
+    @Nonnull
+    Stream<Task> findTasksStream(@Nonnull final TasksQuery query);
+
     /**
      * List all task members.
      *

client/src/main/java/com/influxdb/client/internal/TasksApiImpl.java

@@ -22,9 +22,15 @@
 package com.influxdb.client.internal;
 
 import java.time.OffsetDateTime;
+import java.util.Collections;
+import java.util.Iterator;
 import java.util.List;
+import java.util.Spliterator;
+import java.util.Spliterators;
 import java.util.logging.Level;
 import java.util.logging.Logger;
+import java.util.stream.Stream;
+import java.util.stream.StreamSupport;
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
@@ -147,6 +153,77 @@ public List<Task> findTasks(@Nonnull final TasksQuery query) {
         return tasks.getTasks();
     }
 
+    @Nonnull
+    @Override
+    public Stream<Task> findTasksStream(@Nonnull final TasksQuery query) {
+        Iterator<Task> iterator = new Iterator<Task>() {
+            private boolean hasNext = true;
+
+            @Nonnull
+            private Iterator<Task> tasksIterator = Collections.emptyIterator();
+
+            @Nullable
+            private String after = query.getAfter();
+
+            @Override
+            public boolean hasNext() {
+                if (tasksIterator.hasNext()) {
+                    return true;
+                } else if (hasNext) {
+                    doQueryNext();
+                    return tasksIterator.hasNext();
+                } else {
+                    return false;
+                }
+            }
+
+            private void doQueryNext() {
+                Call<Tasks> call = service.getTasks(null, query.getName(), after, query.getUser(),
+                        query.getOrg(), query.getOrgID(), query.getStatus(), query.getLimit(), query.getType());
+
+                Tasks tasks = execute(call);
+
+                List<Task> tasksList = tasks.getTasks();
+                tasksIterator = tasksList.iterator();
+                if (!tasksList.isEmpty()) {
+                    Task lastTask = tasksList.get(tasksList.size() - 1);
+                    after = lastTask.getId();
+                }
+
+                @Nullable String nextUrl = tasks.getLinks().getNext();
+                hasNext = nextUrl != null && !nextUrl.isEmpty();
+
+                String logMsg = "findTasksStream found: {0} has next page: {1} next after {2}: ";
+                LOG.log(Level.FINEST, logMsg, new Object[]{tasks, hasNext, after});
+            }
+
+            @Override
+            public Task next() throws IndexOutOfBoundsException {
+                if (!tasksIterator.hasNext() && hasNext) {
+                    doQueryNext();
+                }
+
+                if (tasksIterator.hasNext()){
+                    return tasksIterator.next();
+                } else {
+                    throw new IndexOutOfBoundsException();
+                }
+            }
+
+            @Override
+            public void remove() throws UnsupportedOperationException {
+                throw new UnsupportedOperationException();
+            }
+        };
+
+        Stream<Task> stream = StreamSupport.stream(
+            Spliterators.spliteratorUnknownSize(iterator, Spliterator.ORDERED),
+            false);
+
+        return stream;
+
+    }
+
     @Nonnull
     @Override
     public Task createTask(@Nonnull final Task task) {

client/src/test/java/com/influxdb/client/ITTasksApi.java

@@ -29,6 +29,8 @@
 import java.util.List;
 import java.util.Map;
 import java.util.logging.Logger;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 import javax.annotation.Nonnull;
 
 import com.influxdb.client.domain.Authorization;
@@ -49,6 +51,7 @@
 import com.influxdb.exceptions.NotFoundException;
 
 import org.assertj.core.api.Assertions;
+import org.jetbrains.annotations.Nullable;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
@@ -315,6 +318,42 @@ void findTasksAfterSpecifiedID() {
         Assertions.assertThat(tasks.get(0).getId()).isEqualTo(task2.getId());
     }
 
+    @Test
+    void findTasksAll() {
+        String taskName = generateName("it task all");
+        int numOfTasks = 10;
+
+        for (int i = 0; i < numOfTasks; i++) {
+            tasksApi.createTaskCron(taskName, TASK_FLUX, "0 2 * * *", organization);
+        }
+
+        final TasksQuery tasksQuery = new TasksQuery();
+        tasksQuery.setName(taskName);
+
+        List<Task> tasks;
+
+        // get tasks in 3-4 batches
+        tasksQuery.setLimit(numOfTasks / 3);
+        tasks = tasksApi.findTasksStream(tasksQuery).collect(Collectors.toList());
+        Assertions.assertThat(tasks).hasSize(numOfTasks);
+
+        // get tasks in one equally size batch
+        tasksQuery.setLimit(numOfTasks);
+        tasks = tasksApi.findTasksStream(tasksQuery).collect(Collectors.toList());
+        Assertions.assertThat(tasks).hasSize(numOfTasks);
+
+        // get tasks in one batch
+        tasksQuery.setLimit(numOfTasks + 1);
+        tasks = tasksApi.findTasksStream(tasksQuery).collect(Collectors.toList());
+        Assertions.assertThat(tasks).hasSize(numOfTasks);
+
+        // get no tasks
+        tasksQuery.setLimit(null);
+        tasksQuery.setName(taskName + "___");
+        tasks = tasksApi.findTasksStream(tasksQuery).collect(Collectors.toList());
+        Assertions.assertThat(tasks).hasSize(0);
+    }
+
     @Test
     void deleteTask() {