stdlib: Change method to get continuous intervals for Wattson (#3406)

Use counter_leading_intervals!() to get the continuous counters instead
of doing it in SQL. This is ~30-40% faster for all use cases I checked.

There are some differences at the tail end of counters, but this is a
negligible difference.

Test: tools/diff_test_trace_processor.py
out/linux_clang_release/trace_processor_shell --name-filter '.wattson'
--print-slowest-tests
Bug: 454944449

Signed-off-by: Samuel Wu <[email protected]>

Author: wusamuel6

src/trace_processor/perfetto_sql/stdlib/wattson/ui/continuous_estimates.sql

@@ -13,6 +13,8 @@
 -- See the License for the specific language governing permissions and
 -- limitations under the License.
 
+INCLUDE PERFETTO MODULE counters.intervals;
+
 INCLUDE PERFETTO MODULE wattson.estimates;
 
 INCLUDE PERFETTO MODULE wattson.utils;
@@ -26,21 +28,19 @@ CREATE PERFETTO MACRO _get_continuous_estimates(
 )
 RETURNS TableOrSubquery AS
 (
-  WITH
-    base AS (
-      SELECT
-        ts,
-        $rail,
-        lag($rail, 1, $rail) OVER (ORDER BY ts) != $rail AS changed
-      FROM _system_state_mw
-    )
   SELECT
     ts,
-    lead(ts, 1, trace_end()) OVER (ORDER BY ts) - ts AS dur,
-    $rail
-  FROM base
-  WHERE
-    changed
+    dur,
+    value AS $rail
+  FROM counter_leading_intervals!((
+    SELECT
+      ts,
+      dur,
+      $rail AS value,
+      NULL AS id,
+      NULL AS track_id
+    FROM _system_state_mw
+  ))
 );
 
 CREATE PERFETTO TABLE _system_state_cpu0_mw AS

test/trace_processor/diff_tests/metrics/android/wattson_trace_threads.out

@@ -5,10 +5,10 @@ wattson_trace_threads {
   period_info {
     period_id: 1
     task_info {
-      estimated_mws: 34.415909
-      estimated_mw: 3.961489
+      estimated_mws: 34.41899
+      estimated_mw: 3.961843
       idle_transitions_mws: -20.19533
-      total_mws: 14.220581
+      total_mws: 14.22366
       thread_name: "swapper"
       process_name: ""
       thread_id: 0
@@ -1335,10 +1335,10 @@ wattson_trace_threads {
       process_id: 1926
     }
     task_info {
-      estimated_mws: 0.257572
-      estimated_mw: 0.029648
+      estimated_mws: 0.259248
+      estimated_mw: 0.029841
       idle_transitions_mws: 0.187774
-      total_mws: 0.445345
+      total_mws: 0.447021
       thread_name: "kworker/3:5"
       process_name: "kworker/3:5"
       thread_id: 104