Index tasks by git tree hash instead of parent commits hashes

etc/taskcluster/decision_task.py

@@ -27,10 +27,6 @@ def tasks(task_for):
         # https://github.com/taskcluster/taskcluster/blob/21f257dc8/services/github/config.yml#L14
         CONFIG.routes_for_all_subtasks.append("statuses")
 
-    # The magicleap build is broken until there's a surfman back end
-    magicleap_dev = lambda: None
-    magicleap_nightly = lambda: None
-
     if task_for == "github-push":
         all_tests = [
             linux_tidy_unit,
@@ -39,7 +35,6 @@ def tasks(task_for):
             windows_arm64,
             windows_uwp_x64,
             macos_unit,
-            magicleap_dev,
             linux_wpt,
             linux_wpt_layout_2020,
             linux_release,
@@ -61,7 +56,6 @@ def tasks(task_for):
             "try-mac": [macos_unit],
             "try-linux": [linux_tidy_unit, linux_docs_check, linux_release],
             "try-windows": [windows_unit, windows_arm64, windows_uwp_x64],
-            "try-magicleap": [magicleap_dev],
             "try-arm": [windows_arm64],
             "try-wpt": [linux_wpt],
             "try-wpt-2020": [linux_wpt_layout_2020],
@@ -95,19 +89,9 @@ def tasks(task_for):
         windows_nightly()
         macos_nightly()
         update_wpt()
-        magicleap_nightly()
         uwp_nightly()
 
 
-# These are disabled in a "real" decision task,
-# but should still run when testing this Python code. (See `mock.py`.)
-def mocked_only():
-    windows_release()
-    magicleap_dev()
-    magicleap_nightly()
-    decisionlib.DockerWorkerTask("Indexed by task definition").find_or_create()
-
-
 ping_on_daily_task_failure = "SimonSapin, nox, emilio"
 build_artifacts_expire_in = "1 week"
 build_dependencies_artifacts_expire_in = "1 month"
@@ -390,18 +374,6 @@ def windows_unit(cached=True):
         return task.create()
 
 
-def windows_release():
-    return (
-        windows_build_task("Release build")
-        .with_treeherder("Windows x64", "Release")
-        .with_script("mach build --release",
-                     "mach package --release")
-        .with_artifacts("repo/target/release/msi/Servo.exe",
-                        "repo/target/release/msi/Servo.zip")
-        .find_or_create("build.windows_x64_release." + CONFIG.task_id())
-    )
-
-
 def windows_nightly():
     return (
         windows_build_task("Nightly build and upload")
@@ -692,19 +664,6 @@ def wpt_chunks(platform, make_chunk_task, build_task, total_chunks, processes,
 
 
 def daily_tasks_setup():
-    # ':' is not accepted in an index namepspace:
-    # https://docs.taskcluster.net/docs/reference/core/taskcluster-index/references/api
-    now = SHARED.now.strftime("%Y-%m-%d_%H-%M-%S")
-    index_path = "%s.daily.%s" % (CONFIG.index_prefix, now)
-    # Index this task manually rather than with a route,
-    # so that it is indexed even if it fails.
-    SHARED.index_service.insertTask(index_path, {
-        "taskId": CONFIG.decision_task_id,
-        "rank": 0,
-        "data": {},
-        "expires": SHARED.from_now_json(log_artifacts_expire_in),
-    })
-
     # Unlike when reacting to a GitHub push event,
     # the commit hash is not known until we clone the repository.
     CONFIG.git_sha_is_current_head()
@@ -878,60 +837,6 @@ def macos_build_task(name):
     )
 
 
-def magicleap_build_task(name, build_type):
-    return (
-        macos_build_task(name)
-        .with_treeherder("MagicLeap aarch64", build_type)
-        .with_directory_mount(
-            "https://servo-deps.s3.amazonaws.com/magicleap/macos-sdk-v0.20.0%2Bndk19c.tar.gz",
-            sha256="d5890cc7612694d79e60247a5d5fe4d8bdeb797095f098d56f3069be33426781",
-            path="magicleap"
-        )
-        .with_directory_mount(
-            "https://servo-deps.s3.amazonaws.com/magicleap/ServoCICert-expires-2020-08-25.zip",
-            sha256="33f9d07b89c206e671f6a5020e52265b131e83aede8fa474be323a8e3345d760",
-            path="magicleap"
-        )
-        # Early script in order to run with the initial $PWD
-        .with_early_script("""
-            export MAGICLEAP_SDK="$PWD/magicleap/v0.20.0+ndk19c"
-            export MLCERT="$PWD/magicleap/servocimlcert.cert"
-        """)
-        .with_script("""
-            unset OPENSSL_INCLUDE_DIR
-            unset OPENSSL_LIB_DIR
-            export HOST_CC=$(brew --prefix llvm)/bin/clang
-            export HOST_CXX=$(brew --prefix llvm)/bin/clang++
-        """)
-    )
-
-
-def magicleap_dev():
-    return (
-        magicleap_build_task("Dev build", "Dev")
-        .with_script("""
-            ./mach build --magicleap --dev
-            env -u DYLD_LIBRARY_PATH ./mach package --magicleap --dev
-        """)
-        .find_or_create("build.magicleap_dev." + CONFIG.task_id())
-    )
-
-
-def magicleap_nightly():
-    return (
-        magicleap_build_task("Nightly build and upload", "Release")
-        .with_features("taskclusterProxy")
-        .with_scopes("secrets:get:project/servo/s3-upload-credentials")
-        .with_script("""
-            ./mach build --magicleap --release
-            env -u DYLD_LIBRARY_PATH ./mach package --magicleap --release
-            ./mach upload-nightly magicleap --secret-from-taskcluster
-        """)
-        .with_artifacts("repo/target/magicleap/aarch64-linux-android/release/Servo.mpk")
-        .find_or_create("build.magicleap_nightly." + CONFIG.task_id())
-    )
-
-
 CONFIG.task_name_template = "Servo: %s"
 CONFIG.docker_images_expire_in = build_dependencies_artifacts_expire_in
 CONFIG.repacked_msi_files_expire_in = build_dependencies_artifacts_expire_in

etc/taskcluster/decisionlib.py

@@ -65,23 +65,12 @@ def __init__(self):
 
 
     def task_id(self):
-        if hasattr(self, "_task_id"):
-            return self._task_id
-        # If the head commit is a merge, we want to generate a unique task id which incorporates
-        # the merge parents rather that the actual sha of the merge commit. This ensures that tasks
-        # can be reused if the tree is in an identical state. Otherwise, if the head commit is
-        # not a merge, we can rely on the head commit sha for that purpose.
-        raw_commit = subprocess.check_output(["git", "cat-file", "commit", "HEAD"])
-        parent_commits = [
-            value.decode("utf8")
-            for line in raw_commit.split(b"\n")
-            for key, _, value in [line.partition(b" ")]
-            if key == b"parent"
-        ]
-        if len(parent_commits) > 1:
-            self._task_id = "-".join(parent_commits) # pragma: no cover
-        else:
-            self._task_id = self.git_sha # pragma: no cover
+        if not hasattr(self, "_task_id"):
+            # Use the SHA-1 hash of the git "tree" object rather than the commit.
+            # A `@bors-servo retry` command creates a new merge commit with a different commit hash
+            # but with the same tree hash.
+            output = subprocess.check_output(["git", "show", "-s", "--format=%T", "HEAD"])
+            self._task_id = output.decode("utf-8").strip()
         return self._task_id
 
     def git_sha_is_current_head(self):
@@ -279,7 +268,7 @@ def find(index_path):
         print("Found task %s indexed at %s" % (task_id, full_index_path))
         return task_id
 
-    def find_or_create(self, index_path=None):
+    def find_or_create(self, index_path):
         """
         Try to find a task in the Index and return its ID.
 
@@ -292,11 +281,6 @@ def find_or_create(self, index_path=None):
 
         <https://docs.taskcluster.net/docs/reference/core/taskcluster-index/references/api#findTask>
         """
-        if not index_path:
-            worker_type = self.worker_type
-            index_by = json.dumps([worker_type, self.build_worker_payload()]).encode("utf-8")
-            index_path = "by-task-definition." + hashlib.sha256(index_by).hexdigest()
-
         task_id = SHARED.found_or_created_indexed_tasks.get(index_path)
         if task_id is not None:
             return task_id

etc/taskcluster/mock.py

@@ -56,9 +56,6 @@ def findTask(self, path):
 print("\n# Push with hot caches:")
 decision_task.main("github-push")
 
-print("\n# Mocked only:")
-decision_task.mocked_only()
-
 print("\n# Push to master:")
 decision_task.CONFIG.git_ref = "refs/heads/master"
 decision_task.main("github-push")