From 6018f640555ca7f898aa361009ab41c5b161cc48 Mon Sep 17 00:00:00 2001
From: Varun Anand <vaanand@google.com>
Date: Fri, 24 May 2019 16:29:22 -0700
Subject: [PATCH] Addressing comments for http://ag/7700679.

(cherry picked from commit 81e79803dea2c2c4474f1d9cf84384bed2ff65c0)

Note, that its in a separate CL so we could cherry-pick this CL to aosp.
http://ag/7700679 is already in aosp (http://aosp/865073).

Bug: 113122541
Bug: 120145746
Test: atest FrameworksNetTests

Change-Id: Ic1767bc8bf1460e4223f86465fc72344428e6055
Merged-In: I7cfda226b4ed11b67002b83b38fba0f5caf96718
---
 core/java/android/net/NetworkStats.java | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/core/java/android/net/NetworkStats.java b/core/java/android/net/NetworkStats.java
index 27e0414961..b27b1c0578 100644
--- a/core/java/android/net/NetworkStats.java
+++ b/core/java/android/net/NetworkStats.java
@@ -1300,7 +1300,8 @@ public class NetworkStats implements Parcelable {
         }
 
         final Entry tmpEntry = new Entry();
-        for (int i = 0; i < size; i++) {
+        final int origSize = size;
+        for (int i = 0; i < origSize; i++) {
             if (!Objects.equals(iface[i], tunIface)) {
                 // Consider only entries that go onto the VPN interface.
                 continue;
@@ -1316,8 +1317,9 @@ public class NetworkStats implements Parcelable {
             tmpEntry.roaming = roaming[i];
             tmpEntry.defaultNetwork = defaultNetwork[i];
 
-            // In a first pass, compute each UID's total share of data across all underlyingIfaces.
-            // This is computed on the basis of the share of each UID's usage over tunIface.
+            // In a first pass, compute this entry's total share of data across all
+            // underlyingIfaces. This is computed on the basis of the share of this entry's usage
+            // over tunIface.
             // TODO: Consider refactoring first pass into a separate helper method.
             long totalRxBytes = 0;
             if (tunIfaceTotal.rxBytes > 0) {
@@ -1394,9 +1396,11 @@ public class NetworkStats implements Parcelable {
                                     * perInterfaceTotal[j].operations
                                     / underlyingIfacesTotal.operations;
                 }
-
+                // tmpEntry now contains the migrated data of the i-th entry for the j-th underlying
+                // interface. Add that data usage to this object.
                 combineValues(tmpEntry);
                 if (tag[i] == TAG_NONE) {
+                    // Add the migrated data to moved so it is deducted from the VPN app later.
                     moved[j].add(tmpEntry);
                     // Add debug info
                     tmpEntry.set = SET_DBG_VPN_IN;
@@ -1412,8 +1416,8 @@ public class NetworkStats implements Parcelable {
             @NonNull String[] underlyingIfaces,
             @NonNull Entry[] moved) {
         for (int i = 0; i < underlyingIfaces.length; i++) {
-            // Add debug info
             moved[i].uid = tunUid;
+            // Add debug info
             moved[i].set = SET_DBG_VPN_OUT;
             moved[i].tag = TAG_NONE;
             moved[i].iface = underlyingIfaces[i];