From 595c67d790c09c8cd018efd7cc2efa480aeb0b21 Mon Sep 17 00:00:00 2001
From: Hui Ling Shi <huilingshi@google.com>
Date: Wed, 27 Jul 2022 12:29:10 +0000
Subject: [PATCH] [11] Change matching WM/SF entry to IME entry algo

Due to there being some slightly different timestamps between WM/SF
trace and IME trace, we want to allow some "fault tolerance" -- even
if a WM/SF entry comes after IME entry in time, it may still be the
corresponding entry if it's within a manually-defined "fault tolerance"
time.

For now, fault tolerance is defined to be 200ms. So if a WM/SF entry is
within IME entry +- 200ms, it may be considered a matching /
corresponding entry. Within this range, we will always try to pick a
WM/SF entry that comes before the IME entry. If there is no such WM/SF
entry, then we will pick one that comes after.

Bug: 236226833
Test: manual on local build of Winscope
Change-Id: I0782ec520284517bf964eeffd552e6175758c9f1
---
 .../winscope/src/ImeAdditionalProperties.vue  |  8 ++---
 tools/winscope/src/ime_processing.js          | 32 +++++++++++++------
 2 files changed, 26 insertions(+), 14 deletions(-)

diff --git a/tools/winscope/src/ImeAdditionalProperties.vue b/tools/winscope/src/ImeAdditionalProperties.vue
index 53d6c2731..0ecd679a5 100644
--- a/tools/winscope/src/ImeAdditionalProperties.vue
+++ b/tools/winscope/src/ImeAdditionalProperties.vue
@@ -159,13 +159,13 @@
     <div class="group">
       <span class="group-header">Visibility</span>
       <div class="full-width">
-        <span class="key">InputMethod Window:</span>
-        <span class="value">{{
+        <span class="key" v-if="entry.wmProperties">InputMethod Window:</span>
+        <span class="value" v-if="entry.wmProperties">{{
             entry.wmProperties.isInputMethodWindowVisible
           }}</span>
         <div />
-        <span class="key">InputMethod Surface:</span>
-        <span class="value">{{
+        <span class="key" v-if="entry.sfProperties">InputMethod Surface:</span>
+        <span class="value" v-if="entry.sfProperties">{{
             entry.sfProperties.isInputMethodSurfaceVisible }}</span>
         <div />
       </div>
diff --git a/tools/winscope/src/ime_processing.js b/tools/winscope/src/ime_processing.js
index 13c0c1d48..1fe913a78 100644
--- a/tools/winscope/src/ime_processing.js
+++ b/tools/winscope/src/ime_processing.js
@@ -100,23 +100,35 @@ function combineWmSfPropertiesIntoImeData(imeTraceFile, wmOrSfTraceFile) {
 }
 
 function matchCorrespondingTimestamps(imeTimestamps, wmOrSfTimestamps) {
-  // find the latest sf / wm timestamp that comes before current ime timestamp
+  // we want to take the earliest sf / wm entry that is within
+  // +-[FAULT_TOLERANCE] ns of the ime entry as the corresponding sf / wm entry
+  const FAULT_TOLERANCE = 200000000; // 200ms in ns
+
   let wmOrSfIndex = 0;
   const intersectWmOrSfIndices = [];
   for (let imeIndex = 0; imeIndex < imeTimestamps.length; imeIndex++) {
     const currImeTimestamp = imeTimestamps[imeIndex];
-
-    let currWmOrSfTimestamp = wmOrSfTimestamps[wmOrSfIndex];
-    while (currWmOrSfTimestamp < currImeTimestamp) {
+    let wmOrSfTimestamp = wmOrSfTimestamps[wmOrSfIndex];
+    while (wmOrSfTimestamp < currImeTimestamp) {
       wmOrSfIndex++;
-      currWmOrSfTimestamp = wmOrSfTimestamps[wmOrSfIndex];
+      wmOrSfTimestamp = wmOrSfTimestamps[wmOrSfIndex];
+    }
+    // wmOrSfIndex should now be at the first entry that is past
+    // [currImeTimestamp] ns. We want the most recent entry that comes
+    // before [currImeTimestamp] ns if it's within
+    // [currImeTimestamp - FAULT_TOLERANCE] ns. Otherwise, we want the most
+    // recent entry that comes after [currImeTimestamp] ns if it's within
+    // [currImeTimestamp + FAULT_TOLERANCE] ns.
+    const previousWmOrSfTimestamp = wmOrSfTimestamps[wmOrSfIndex - 1];
+    if (previousWmOrSfTimestamp >= currImeTimestamp - FAULT_TOLERANCE) {
+      intersectWmOrSfIndices.push(wmOrSfIndex - 1);
+    } else if (wmOrSfTimestamp <= currImeTimestamp + FAULT_TOLERANCE) {
+      intersectWmOrSfIndices.push(wmOrSfIndex);
+    } else {
+      intersectWmOrSfIndices.push(null);
     }
-    // if wmOrSfIndex is 0, i.e. no corresponding entry is found,
-    // we take the first wm / sf entry
-    // intersectWmOrSfIndices.push(Math.max(0, wmOrSfIndex - 1));
-    intersectWmOrSfIndices.push(wmOrSfIndex - 1);
   }
-  console.log('done matching corresponding timestamps');
+  console.log('done matching corresponding timestamps', intersectWmOrSfIndices);
   return intersectWmOrSfIndices;
 }