Add incrementValue method

Bug: 191921016
Test: atest libbattery

Change-Id: Ia10999854eef99d47b7968d23881a39d9976be24

2 files changed, 42 insertions, 4 deletions

diff --git a/libs/battery/MultiStateCounter.h b/libs/battery/MultiStateCounter.h
index a2b59a877f..0caf005a9a 100644
--- a/libs/battery/MultiStateCounter.h
+++ b/libs/battery/MultiStateCounter.h
@@ -63,12 +63,24 @@ public:
     void setValue(state_t state, const T& value);
 
     /**
-     * Updates the value for the current state and returns the delta from the previously
-     * set value.
+     * Updates the value by distributing the delta from the previously set value
+     * among states according to their respective time-in-state.
+     * Returns the delta from the previously set value.
      */
     const T& updateValue(const T& value, time_t timestamp);
 
-    void addValue(const T& value);
+    /**
+     * Updates the value by distributing the specified increment among states according
+     * to their respective time-in-state.
+     */
+    void incrementValue(const T& increment, time_t timestamp);
+
+    /**
+     * Adds the specified increment to the value for the current state, without affecting
+     * the last updated value or timestamp.  Ignores partial time-in-state: the entirety of
+     * the increment is given to the current state.
+     */
+    void addValue(const T& increment);
 
     void reset();
 
@@ -216,11 +228,17 @@ const T& MultiStateCounter<T>::updateValue(const T& value, time_t timestamp) {
 }
 
 template <class T>
+void MultiStateCounter<T>::incrementValue(const T& increment, time_t timestamp) {
+    T newValue = lastValue;
+    add(&newValue, increment, 1 /* numerator */, 1 /* denominator */);
+    updateValue(newValue, timestamp);
+}
+
+template <class T>
 void MultiStateCounter<T>::addValue(const T& value) {
     if (!isEnabled) {
         return;
     }
-
     add(&states[currentState].counter, value, 1 /* numerator */, 1 /* denominator */);
 }
 
diff --git a/libs/battery/MultiStateCounterTest.cpp b/libs/battery/MultiStateCounterTest.cpp
index 876bf745a8..cb11a5444d 100644
--- a/libs/battery/MultiStateCounterTest.cpp
+++ b/libs/battery/MultiStateCounterTest.cpp
@@ -210,6 +210,26 @@ TEST_F(MultiStateCounterTest, updateValue_nonmonotonic) {
     EXPECT_DOUBLE_EQ(3.0, delta);
 }
 
+TEST_F(MultiStateCounterTest, incrementValue) {
+    DoubleMultiStateCounter testCounter(2, 0);
+    testCounter.updateValue(0, 0);
+    testCounter.setState(0, 0);
+    testCounter.updateValue(6.0, 2000);
+
+    testCounter.setState(1, 3000);
+
+    testCounter.incrementValue(8.0, 6000);
+
+    // The total accumulated count is:
+    //  6.0             // For the period 0-2000
+    //  +(8.0 * 0.25)   // For the period 3000-4000
+    EXPECT_DOUBLE_EQ(8.0, testCounter.getCount(0));
+
+    // 0                // For the period 0-3000
+    // +(8.0 * 0.75)    // For the period 3000-4000
+    EXPECT_DOUBLE_EQ(6.0, testCounter.getCount(1));
+}
+
 TEST_F(MultiStateCounterTest, addValue) {
     DoubleMultiStateCounter testCounter(1, 0);
     testCounter.updateValue(0, 0);