Add MultiStateCounter
This native object is used to track values per-state. For example,
if the state changes from 0 to 1 between two updateValue calls,
the delta between the values is distributed to the states 0 and 1
in accordance with the time spent in those states.
Bug: 197162116
Test: atest libbattery_test
Change-Id: Ie304db5c93f4aa9676d12d0a8ab53b6867b24fff
diff --git a/libs/battery/LongArrayMultiStateCounter.cpp b/libs/battery/LongArrayMultiStateCounter.cpp
new file mode 100644
index 0000000..68e0883
--- /dev/null
+++ b/libs/battery/LongArrayMultiStateCounter.cpp
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ * Android BPF library - public API
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "LongArrayMultiStateCounter.h"
+#include <log/log.h>
+
+namespace android {
+namespace battery {
+
+template <>
+bool LongArrayMultiStateCounter::delta(const std::vector<uint64_t>& previousValue,
+ const std::vector<uint64_t>& newValue,
+ std::vector<uint64_t>* outValue) const {
+ size_t size = previousValue.size();
+ if (newValue.size() != size) {
+ ALOGE("Incorrect array size: %d, should be %d", (int)newValue.size(), (int)size);
+ return false;
+ }
+
+ bool is_delta_valid = true;
+ for (int i = size - 1; i >= 0; i--) {
+ if (newValue[i] >= previousValue[i]) {
+ (*outValue)[i] = newValue[i] - previousValue[i];
+ } else {
+ (*outValue)[i] = 0;
+ is_delta_valid = false;
+ }
+ }
+ return is_delta_valid;
+}
+
+template <>
+void LongArrayMultiStateCounter::add(std::vector<uint64_t>* value1,
+ const std::vector<uint64_t>& value2, const uint64_t numerator,
+ const uint64_t denominator) const {
+ if (numerator != denominator) {
+ for (int i = value2.size() - 1; i >= 0; i--) {
+ // The caller ensures that denominator != 0
+ (*value1)[i] += value2[i] * numerator / denominator;
+ }
+ } else {
+ for (int i = value2.size() - 1; i >= 0; i--) {
+ (*value1)[i] += value2[i];
+ }
+ }
+}
+
+template <>
+std::string LongArrayMultiStateCounter::valueToString(const std::vector<uint64_t>& v) const {
+ std::stringstream s;
+ s << "{ ";
+ bool first = true;
+ for (uint64_t n : v) {
+ if (!first) {
+ s << ", ";
+ }
+ s << n;
+ first = false;
+ }
+ s << "}";
+ return s.str();
+}
+
+} // namespace battery
+} // namespace android