feat: task pagination (#616)

Author: Sciator

CHANGELOG.md

@@ -1,5 +1,8 @@
 ## 1.39.0 [unreleased]
 
+### Features
+1. [#616](https://github.com/influxdata/influxdb-client-python/pull/616): Add `find_tasks_iter` function that allow iterate through all pages of tasks.
+
 ## 1.38.0 [2023-10-02]
 
 ### Bug Fixes

examples/task_example.py

@@ -25,3 +25,9 @@
     task_request = TaskCreateRequest(flux=flux, org=org, description="Task Description", status="active")
     task = tasks_api.create_task(task_create_request=task_request)
     print(task)
+
+    tasks = tasks_api.find_tasks_iter()
+
+    # print all tasks id
+    for task in tasks:
+        print(task.id)

influxdb_client/client/tasks_api.py

@@ -11,6 +11,38 @@
     AddResourceMemberRequestBody, RunManually, Run, LogEvent
 
 
+class _Page:
+    def __init__(self, values, has_next, next_after):
+        self.has_next = has_next
+        self.values = values
+        self.next_after = next_after
+
+    @staticmethod
+    def empty():
+        return _Page([], False, None)
+
+    @staticmethod
+    def initial(after):
+        return _Page([], True, after)
+
+
+class _PageIterator:
+    def __init__(self, page: _Page, get_next_page):
+        self.page = page
+        self.get_next_page = get_next_page
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        if not self.page.values:
+            if self.page.has_next:
+                self.page = self.get_next_page(self.page)
+            if not self.page.values:
+                raise StopIteration
+        return self.page.values.pop(0)
+
+
 class TasksApi(object):
     """Implementation for '/api/v2/tasks' endpoint."""
 
@@ -25,7 +57,7 @@ def find_task_by_id(self, task_id) -> Task:
         return task
 
     def find_tasks(self, **kwargs):
-        """List all tasks.
+        """List all tasks up to set limit (max 500).
 
         :key str name: only returns tasks with the specified name
         :key str after: returns tasks after specified ID
@@ -37,6 +69,23 @@ def find_tasks(self, **kwargs):
         """
         return self._service.get_tasks(**kwargs).tasks
 
+    def find_tasks_iter(self, **kwargs):
+        """Iterate over all tasks with pagination.
+
+        :key str name: only returns tasks with the specified name
+        :key str after: returns tasks after specified ID
+        :key str user: filter tasks to a specific user ID
+        :key str org: filter tasks to a specific organization name
+        :key str org_id: filter tasks to a specific organization ID
+        :key int limit: the number of tasks in one page
+        :return: Tasks iterator
+        """
+
+        def get_next_page(page: _Page):
+            return self._find_tasks_next_page(page, **kwargs)
+
+        return iter(_PageIterator(_Page.initial(kwargs.get('after')), get_next_page))
+
     def create_task(self, task: Task = None, task_create_request: TaskCreateRequest = None) -> Task:
         """Create a new task."""
         if task_create_request is not None:
@@ -210,3 +259,16 @@ def get_logs(self, task_id: str) -> List['LogEvent']:
     def find_tasks_by_user(self, task_user_id):
         """List all tasks by user."""
         return self.find_tasks(user=task_user_id)
+
+    def _find_tasks_next_page(self, page: _Page, **kwargs):
+        if not page.has_next:
+            return _Page.empty()
+
+        args = {**kwargs, 'after': page.next_after} if page.next_after is not None else kwargs
+        tasks_response = self._service.get_tasks(**args)
+
+        tasks = tasks_response.tasks
+        has_next = tasks_response.links.next is not None
+        last_id = tasks[-1].id if tasks else None
+
+        return _Page(tasks, has_next, last_id)

tests/test_TasksApi.py

@@ -184,6 +184,37 @@ def test_find_task_by_user_id(self):
         print(tasks)
         self.assertEqual(len(tasks), 1)
 
+    def test_find_tasks_iter(self):
+        task_name = self.generate_name("it task")
+        num_of_tasks = 10
+
+        for _ in range(num_of_tasks):
+            self.tasks_api.create_task_cron(task_name, TASK_FLUX, "0 2 * * *", self.organization.id)
+
+        def count_unique_ids(tasks):
+            return len(set(map(lambda task: task.id, tasks)))
+
+        # get tasks in 3-4 batches
+        tasks = self.tasks_api.find_tasks_iter(name= task_name, limit= num_of_tasks // 3)
+        self.assertEqual(count_unique_ids(tasks), num_of_tasks)
+
+        # get tasks in one equaly size batch
+        tasks = self.tasks_api.find_tasks_iter(name= task_name, limit= num_of_tasks)
+        self.assertEqual(count_unique_ids(tasks), num_of_tasks)
+
+        # get tasks in one batch
+        tasks = self.tasks_api.find_tasks_iter(name= task_name, limit= num_of_tasks + 1)
+        self.assertEqual(count_unique_ids(tasks), num_of_tasks)
+
+        # get no tasks
+        tasks = self.tasks_api.find_tasks_iter(name= task_name + "blah")
+        self.assertEqual(count_unique_ids(tasks), 0)
+
+        # skip some tasks
+        *_, split_task = self.tasks_api.find_tasks(name= task_name, limit= num_of_tasks // 3)
+        tasks = self.tasks_api.find_tasks_iter(name= task_name, limit= 3, after= split_task.id)
+        self.assertEqual(count_unique_ids(tasks), num_of_tasks - num_of_tasks // 3)
+
     def test_delete_task(self):
         task = self.tasks_api.create_task_cron(self.generate_name("it_task"), TASK_FLUX, "0 2 * * *",
                                                self.organization.id)