1 files changed, 159 insertions, 0 deletions
diff --git a/cmds/statsd/src/state/StateTracker.cpp b/cmds/statsd/src/state/StateTracker.cpp
new file mode 100644
index 000000000000..323fc0e94ab2
--- /dev/null
+++ b/cmds/statsd/src/state/StateTracker.cpp
@@ -0,0 +1,159 @@
+/*
+ * Copyright (C) 2019, The Android Open Source Project
+ *
+ * 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.
+ */
+
+#define DEBUG true  // STOPSHIP if true
+#include "Log.h"
+
+#include "stats_util.h"
+
+#include "StateTracker.h"
+
+namespace android {
+namespace os {
+namespace statsd {
+
+StateTracker::StateTracker(const int atomId,
+                           const util::StateAtomFieldOptions& stateAtomInfo)
+  : mAtomId(atomId),
+    mStateField(getSimpleMatcher(atomId, stateAtomInfo.exclusiveField)) {
+    // create matcher for each primary field
+    // TODO(tsaichristine): b/142108433 handle when primary field is first uid in chain
+    for (const auto& primary : stateAtomInfo.primaryFields) {
+        Matcher matcher = getSimpleMatcher(atomId, primary);
+        mPrimaryFields.push_back(matcher);
+    }
+
+    // TODO(tsaichristine): b/142108433 set default state, reset state, and nesting
+}
+
+void StateTracker::onLogEvent(const LogEvent& event) {
+    // parse event for primary field values i.e. primary key
+    HashableDimensionKey primaryKey;
+    if (mPrimaryFields.size() > 0) {
+        if (!filterValues(mPrimaryFields, event.getValues(), &primaryKey) ||
+            primaryKey.getValues().size() != mPrimaryFields.size()) {
+            ALOGE("StateTracker error extracting primary key from log event.");
+            handleReset();
+            return;
+        }
+    } else {
+        // atom has no primary fields
+        primaryKey = DEFAULT_DIMENSION_KEY;
+    }
+
+    // parse event for state value
+    Value state;
+    int32_t stateValue;
+    if (!filterValues(mStateField, event.getValues(), &state) || state.getType() != INT) {
+        ALOGE("StateTracker error extracting state from log event. Type: %d", state.getType());
+        handlePartialReset(primaryKey);
+        return;
+    }
+    stateValue = state.int_value;
+
+    if (stateValue == mResetState) {
+        VLOG("StateTracker Reset state: %s", state.toString().c_str());
+        handleReset();
+    }
+
+    // track and update state
+    int32_t oldState = 0;
+    int32_t newState = 0;
+    updateState(primaryKey, stateValue, &oldState, &newState);
+
+    // notify all listeners if state has changed
+    if (oldState != newState) {
+        VLOG("StateTracker updated state");
+        for (auto listener : mListeners) {
+            auto sListener = listener.promote();  // safe access to wp<>
+            if (sListener != nullptr) {
+                sListener->onStateChanged(mAtomId, primaryKey, oldState, newState);
+            }
+        }
+    } else {
+        VLOG("StateTracker NO updated state");
+    }
+}
+
+void StateTracker::registerListener(wp<StateListener> listener) {
+    mListeners.insert(listener);
+}
+
+void StateTracker::unregisterListener(wp<StateListener> listener) {
+    mListeners.erase(listener);
+}
+
+int StateTracker::getStateValue(const HashableDimensionKey& queryKey) const {
+    if (queryKey.getValues().size() == mPrimaryFields.size()) {
+        auto it = mStateMap.find(queryKey);
+        if (it != mStateMap.end()) {
+            return it->second.state;
+        }
+    } else if (queryKey.getValues().size() > mPrimaryFields.size()) {
+        ALOGE("StateTracker query key size > primary key size is illegal");
+    } else {
+        ALOGE("StateTracker query key size < primary key size is not supported");
+    }
+    return mDefaultState;
+}
+
+void StateTracker::handleReset() {
+    VLOG("StateTracker handle reset");
+    for (const auto pair : mStateMap) {
+        for (auto l : mListeners) {
+            auto sl = l.promote();
+            if (sl != nullptr) {
+                sl->onStateChanged(mAtomId, pair.first, pair.second.state, mDefaultState);
+            }
+        }
+    }
+    mStateMap.clear();
+}
+
+void StateTracker::handlePartialReset(const HashableDimensionKey& primaryKey) {
+    VLOG("StateTracker handle partial reset");
+    if (mStateMap.find(primaryKey) != mStateMap.end()) {
+        mStateMap.erase(primaryKey);
+    }
+}
+
+void StateTracker::updateState(const HashableDimensionKey& primaryKey, const int32_t eventState,
+                               int32_t* oldState, int32_t* newState) {
+    // get old state (either current state in map or default state)
+    auto it = mStateMap.find(primaryKey);
+    if (it != mStateMap.end()) {
+        *oldState = it->second.state;
+    } else {
+        *oldState = mDefaultState;
+    }
+
+    // update state map
+    if (eventState == mDefaultState) {
+        // remove (key, state) pair if state returns to default state
+        VLOG("\t StateTracker changed to default state")
+        mStateMap.erase(primaryKey);
+    } else {
+        mStateMap[primaryKey].state = eventState;
+        mStateMap[primaryKey].count = 1;
+    }
+    *newState = eventState;
+
+    // TODO(tsaichristine): support atoms with nested counting
+}
+
+}  // namespace statsd
+}  // namespace os
+}  // namespace android