From d5af2ead56f6c2f209d96ac3909b4cc92bb64f99 Mon Sep 17 00:00:00 2001
From: Neharika Jali <neharikajali@google.com>
Date: Wed, 20 Oct 2021 06:55:04 +0000
Subject: [PATCH] In low storage, recalculate cache quotas if 2% change in
 total space

Bug: 203651230
Test: manual
Change-Id: Ie5df873f41e0bd0beca430b8e8ec51d5305bb844
---
 .../server/usage/StorageStatsService.java     | 22 ++++++++++++++-----
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/services/usage/java/com/android/server/usage/StorageStatsService.java b/services/usage/java/com/android/server/usage/StorageStatsService.java
index 2d3b9286d69af..88725a6ea1b9a 100644
--- a/services/usage/java/com/android/server/usage/StorageStatsService.java
+++ b/services/usage/java/com/android/server/usage/StorageStatsService.java
@@ -552,23 +552,26 @@ public class StorageStatsService extends IStorageStatsManager.Stub {
         private static final int MSG_PACKAGE_REMOVED = 103;
         /**
          * By only triggering a re-calculation after the storage has changed sizes, we can avoid
-         * recalculating quotas too often. Minimum change delta defines the percentage of change
-         * we need to see before we recalculate.
+         * recalculating quotas too often. Minimum change delta high and low define the
+         * percentage of change we need to see before we recalculate quotas when the device has
+         * enough storage space (more than StorageManager.STORAGE_THRESHOLD_PERCENT_HIGH of total
+         * free) and in low storage condition respectively.
          */
-        private static final double MINIMUM_CHANGE_DELTA = 0.05;
+        private static final long MINIMUM_CHANGE_DELTA_PERCENT_HIGH = 5;
+        private static final long MINIMUM_CHANGE_DELTA_PERCENT_LOW = 2;
         private static final int UNSET = -1;
         private static final boolean DEBUG = false;
 
         private final StatFs mStats;
         private long mPreviousBytes;
-        private double mMinimumThresholdBytes;
+        private long mTotalBytes;
 
         public H(Looper looper) {
             super(looper);
             // TODO: Handle all private volumes.
             mStats = new StatFs(Environment.getDataDirectory().getAbsolutePath());
             mPreviousBytes = mStats.getAvailableBytes();
-            mMinimumThresholdBytes = mStats.getTotalBytes() * MINIMUM_CHANGE_DELTA;
+            mTotalBytes = mStats.getTotalBytes();
         }
 
         public void handleMessage(Message msg) {
@@ -584,7 +587,14 @@ public class StorageStatsService extends IStorageStatsManager.Stub {
                 case MSG_CHECK_STORAGE_DELTA: {
                     mStats.restat(Environment.getDataDirectory().getAbsolutePath());
                     long bytesDelta = Math.abs(mPreviousBytes - mStats.getAvailableBytes());
-                    if (bytesDelta > mMinimumThresholdBytes) {
+                    long bytesDeltaThreshold;
+                    if (mStats.getAvailableBytes() >  mTotalBytes
+                            * StorageManager.STORAGE_THRESHOLD_PERCENT_HIGH / 100) {
+                        bytesDeltaThreshold = mTotalBytes * MINIMUM_CHANGE_DELTA_PERCENT_HIGH / 100;
+                    } else {
+                        bytesDeltaThreshold = mTotalBytes * MINIMUM_CHANGE_DELTA_PERCENT_LOW / 100;
+                    }
+                    if (bytesDelta > bytesDeltaThreshold) {
                         mPreviousBytes = mStats.getAvailableBytes();
                         recalculateQuotas(getInitializedStrategy());
                         notifySignificantDelta();