format timestamp as hh:mm:ss.sss

Test: ./incremental_build.py -c 'no change' -- nothing
Bug: NA
Change-Id: I23d03d1d7938fbbb575945c36712cc9a411d8eb9

4 files changed, 27 insertions, 7 deletions

diff --git a/scripts/incremental_build/incremental_build.py b/scripts/incremental_build/incremental_build.py
index 629cace2..983caade 100755
--- a/scripts/incremental_build/incremental_build.py
+++ b/scripts/incremental_build/incremental_build.py
@@ -139,7 +139,7 @@ def _build(build_type: ui.BuildType, logfile: Path) -> (int, BuildInfo):
     'log': str(logfile.relative_to(ui.get_user_input().log_dir)),
     'ninja_explains': util.count_explanations(logfile),
     'actions': action_count_after - action_count_before,
-    'time': str(datetime.timedelta(microseconds=elapsed_ns / 1000))
+    'time': util.hhmmss(datetime.timedelta(microseconds=elapsed_ns / 1000))
   })
 
 
diff --git a/scripts/incremental_build/perf_metrics.py b/scripts/incremental_build/perf_metrics.py
index 0ee4b253..de1079f6 100755
--- a/scripts/incremental_build/perf_metrics.py
+++ b/scripts/incremental_build/perf_metrics.py
@@ -81,7 +81,7 @@ def archive_run(d: Path, build_info: dict[str, any]):
     json.dump(build_info, f, indent=True)
 
 
-def read_pbs(d: Path) -> dict[str, datetime.timedelta]:
+def read_pbs(d: Path) -> dict[str, str]:
   """
   Reads metrics data from pb files and archives the file by copying
   them under the log_dir.
@@ -110,8 +110,8 @@ def read_pbs(d: Path) -> dict[str, datetime.timedelta]:
   def normalize(desc: str) -> str:
     return re.sub(r'^(?:soong_build|mixed_build)', '*', desc)
 
-  return {f'{m.name}/{normalize(m.description)}': str(m.real_time) for m in
-          events}
+  return {f'{m.name}/{normalize(m.description)}': util.hhmmss(m.real_time) for m
+          in events}
 
 
 def _read_pb(
diff --git a/scripts/incremental_build/util.py b/scripts/incremental_build/util.py
index 28eafd8e..fdc28a14 100644
--- a/scripts/incremental_build/util.py
+++ b/scripts/incremental_build/util.py
@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import csv
+import datetime
 import functools
 import glob
 import logging
@@ -30,9 +31,9 @@ RUN_DIR_PREFIX: Final[str] = 'run'
 BUILD_INFO_JSON: Final[str] = 'build_info.json'
 
 _IMPORTANT_METRICS: set[str] = {r'soong/bootstrap', r'soong_build/\*\.bazel',
-                               r'ninja/ninja', r'bp2build/',
-                               r'symlink_forest/',
-                               r'.*write_files.*'}
+                                r'ninja/ninja', r'bp2build/',
+                                r'symlink_forest/',
+                                r'.*write_files.*'}
 
 
 @functools.cache
@@ -241,3 +242,10 @@ def any_match_under(root: Path, *patterns: str) -> (Path, list[str]):
     children.sort()
     bfs.extend(children)
   raise RuntimeError(f'No suitable directory for {patterns}')
+
+
+def hhmmss(t: datetime.timedelta) -> str:
+  h, f = divmod(t.seconds, 60 * 60)
+  m, f = divmod(f, 60)
+  s = f + t.microseconds / 1000_000
+  return f'{h:02d}:{m:02d}:{s:06.3f}'
diff --git a/scripts/incremental_build/util_test.py b/scripts/incremental_build/util_test.py
index 204d99f5..0e68bc3a 100644
--- a/scripts/incremental_build/util_test.py
+++ b/scripts/incremental_build/util_test.py
@@ -11,12 +11,14 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+import datetime
 import os
 import unittest
 
 from util import _next_path_helper
 from util import any_match
 from util import get_top_dir
+from util import hhmmss
 
 
 class UtilTest(unittest.TestCase):
@@ -73,3 +75,13 @@ class UtilTest(unittest.TestCase):
     for _, dirs, files in os.walk(path):
       self.assertFalse('BUILD' in dirs)
       self.assertFalse('BUILD' in files)
+
+  def test_hhmmss(self):
+    examples = [
+        (datetime.timedelta(seconds=(2 * 60 + 5)), '00:02:05.000'),
+        (datetime.timedelta(seconds=(3600 + 23 * 60 + 45.897898)),
+         '01:23:45.898'),
+    ]
+    for (ts, expected) in examples:
+      self.subTest(ts=ts, expected=expected)
+      self.assertEqual(hhmmss(ts), expected)