1 files changed, 64 insertions, 0 deletions
diff --git a/third_party/python/taskcluster_taskgraph/taskgraph/optimize/strategies.py b/third_party/python/taskcluster_taskgraph/taskgraph/optimize/strategies.py
new file mode 100644
index 0000000000..973b550632
--- /dev/null
+++ b/third_party/python/taskcluster_taskgraph/taskgraph/optimize/strategies.py
@@ -0,0 +1,64 @@
+import logging
+from datetime import datetime
+
+from taskgraph import files_changed
+from taskgraph.optimize.base import OptimizationStrategy, register_strategy
+from taskgraph.util.taskcluster import find_task_id, status_task
+
+logger = logging.getLogger(__name__)
+
+
+@register_strategy("index-search")
+class IndexSearch(OptimizationStrategy):
+    # A task with no dependencies remaining after optimization will be replaced
+    # if artifacts exist for the corresponding index_paths.
+    # Otherwise, we're in one of the following cases:
+    # - the task has un-optimized dependencies
+    # - the artifacts have expired
+    # - some changes altered the index_paths and new artifacts need to be
+    # created.
+    # In every of those cases, we need to run the task to create or refresh
+    # artifacts.
+
+    fmt = "%Y-%m-%dT%H:%M:%S.%fZ"
+
+    def should_replace_task(self, task, params, deadline, index_paths):
+        "Look for a task with one of the given index paths"
+        for index_path in index_paths:
+            try:
+                task_id = find_task_id(index_path)
+                status = status_task(task_id)
+                # status can be `None` if we're in `testing` mode
+                # (e.g. test-action-callback)
+                if not status or status.get("state") in ("exception", "failed"):
+                    continue
+
+                if deadline and datetime.strptime(
+                    status["expires"], self.fmt
+                ) < datetime.strptime(deadline, self.fmt):
+                    continue
+
+                return task_id
+            except KeyError:
+                # 404 will end up here and go on to the next index path
+                pass
+
+        return False
+
+
+@register_strategy("skip-unless-changed")
+class SkipUnlessChanged(OptimizationStrategy):
+    def should_remove_task(self, task, params, file_patterns):
+        # pushlog_id == -1 - this is the case when run from a cron.yml job or on a git repository
+        if params.get("repository_type") == "hg" and params.get("pushlog_id") == -1:
+            return False
+
+        changed = files_changed.check(params, file_patterns)
+        if not changed:
+            logger.debug(
+                'no files found matching a pattern in `skip-unless-changed` for "{}"'.format(
+                    task.label
+                )
+            )
+            return True
+        return False