1 files changed, 122 insertions, 0 deletions
diff --git a/taskcluster/taskgraph/create.py b/taskcluster/taskgraph/create.py
new file mode 100644
index 000000000..f577f8873
--- /dev/null
+++ b/taskcluster/taskgraph/create.py
@@ -0,0 +1,122 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+from __future__ import absolute_import, print_function, unicode_literals
+
+import concurrent.futures as futures
+import requests
+import requests.adapters
+import json
+import os
+import logging
+
+from slugid import nice as slugid
+from taskgraph.util.time import (
+    current_json_time,
+    json_time_from_now
+)
+
+logger = logging.getLogger(__name__)
+
+# the maximum number of parallel createTask calls to make
+CONCURRENCY = 50
+
+
+def create_tasks(taskgraph, label_to_taskid, params):
+    taskid_to_label = {t: l for l, t in label_to_taskid.iteritems()}
+
+    session = requests.Session()
+
+    # Default HTTPAdapter uses 10 connections. Mount custom adapter to increase
+    # that limit. Connections are established as needed, so using a large value
+    # should not negatively impact performance.
+    http_adapter = requests.adapters.HTTPAdapter(pool_connections=CONCURRENCY,
+                                                 pool_maxsize=CONCURRENCY)
+    session.mount('https://', http_adapter)
+    session.mount('http://', http_adapter)
+
+    decision_task_id = os.environ.get('TASK_ID')
+
+    # when running as an actual decision task, we use the decision task's
+    # taskId as the taskGroupId.  The process that created the decision task
+    # helpfully placed it in this same taskGroup.  If there is no $TASK_ID,
+    # fall back to a slugid
+    task_group_id = decision_task_id or slugid()
+    scheduler_id = 'gecko-level-{}'.format(params['level'])
+
+    with futures.ThreadPoolExecutor(CONCURRENCY) as e:
+        fs = {}
+
+        # We can't submit a task until its dependencies have been submitted.
+        # So our strategy is to walk the graph and submit tasks once all
+        # their dependencies have been submitted.
+        #
+        # Using visit_postorder() here isn't the most efficient: we'll
+        # block waiting for dependencies of task N to submit even though
+        # dependencies for task N+1 may be finished. If we need to optimize
+        # this further, we can build a graph of task dependencies and walk
+        # that.
+        for task_id in taskgraph.graph.visit_postorder():
+            task_def = taskgraph.tasks[task_id].task
+            attributes = taskgraph.tasks[task_id].attributes
+            # if this task has no dependencies, make it depend on this decision
+            # task so that it does not start immediately; and so that if this loop
+            # fails halfway through, none of the already-created tasks run.
+            if decision_task_id and not task_def.get('dependencies'):
+                task_def['dependencies'] = [decision_task_id]
+
+            task_def['taskGroupId'] = task_group_id
+            task_def['schedulerId'] = scheduler_id
+
+            # Wait for dependencies before submitting this.
+            deps_fs = [fs[dep] for dep in task_def.get('dependencies', [])
+                       if dep in fs]
+            for f in futures.as_completed(deps_fs):
+                f.result()
+
+            fs[task_id] = e.submit(_create_task, session, task_id,
+                                   taskid_to_label[task_id], task_def)
+
+            # Schedule tasks as many times as task_duplicates indicates
+            for i in range(1, attributes.get('task_duplicates', 1)):
+                # We use slugid() since we want a distinct task id
+                fs[task_id] = e.submit(_create_task, session, slugid(),
+                                       taskid_to_label[task_id], task_def)
+
+        # Wait for all futures to complete.
+        for f in futures.as_completed(fs.values()):
+            f.result()
+
+
+def _create_task(session, task_id, label, task_def):
+    # create the task using 'http://taskcluster/queue', which is proxied to the queue service
+    # with credentials appropriate to this job.
+
+    # Resolve timestamps
+    now = current_json_time(datetime_format=True)
+    task_def = resolve_timestamps(now, task_def)
+
+    logger.debug("Creating task with taskId {} for {}".format(task_id, label))
+    res = session.put('http://taskcluster/queue/v1/task/{}'.format(task_id),
+                      data=json.dumps(task_def))
+    if res.status_code != 200:
+        try:
+            logger.error(res.json()['message'])
+        except:
+            logger.error(res.text)
+        res.raise_for_status()
+
+
+def resolve_timestamps(now, task_def):
+    def recurse(val):
+        if isinstance(val, list):
+            return [recurse(v) for v in val]
+        elif isinstance(val, dict):
+            if val.keys() == ['relative-datestamp']:
+                return json_time_from_now(val['relative-datestamp'], now)
+            else:
+                return {k: recurse(v) for k, v in val.iteritems()}
+        else:
+            return val
+    return recurse(task_def)