More complete implementation for condition and log matchers in statsd.

+ also synced proto from google3 to fix the LogEntryMatcher proto

+ MetricsManager represents StatsdConfig, it's responsible for initializing and managing all
LogEntryMatcher, Condition, and Metrics. Start review from here.

+ Added more complete StatsdConfig initialization, including building the map for:
    LogEntryMatcher -> Metrics
    LogEntryMatcher -> Condition
    Condition       -> Metrics.

    All the maps use index(int). The extra amount of memory for storing mappings help us
    quickly process log events.

  The StatsdConfig initialization process detects malformed config
  - Circle dependency
  - Missing definition
  etc.

 And once we detect ANY error, statsd will reject the config. And the resources related to this
 config will be released.

Test: Added unit tests
Change-Id: I2c4aefdbf3e2aa1701eacbb2fb5e653819ec1fbb
diff --git a/cmds/statsd/src/condition/CombinationConditionTracker.cpp b/cmds/statsd/src/condition/CombinationConditionTracker.cpp
new file mode 100644
index 0000000..6188383
--- /dev/null
+++ b/cmds/statsd/src/condition/CombinationConditionTracker.cpp
@@ -0,0 +1,136 @@
+/*
+ * Copyright (C) 2017 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 LOG_TAG "CombinationConditionTracker"
+#define DEBUG true  // STOPSHIP if true
+#define VLOG(...) \
+    if (DEBUG) ALOGD(__VA_ARGS__);
+
+#include "CombinationConditionTracker.h"
+#include <cutils/log.h>
+#include <log/logprint.h>
+using std::string;
+using std::unique_ptr;
+using std::unordered_map;
+using std::vector;
+
+namespace android {
+namespace os {
+namespace statsd {
+
+CombinationConditionTracker::CombinationConditionTracker(const string& name, const int index)
+    : ConditionTracker(name, index) {
+    VLOG("creating CombinationConditionTracker %s", mName.c_str());
+}
+
+CombinationConditionTracker::~CombinationConditionTracker() {
+    VLOG("~CombinationConditionTracker() %s", mName.c_str());
+}
+
+bool CombinationConditionTracker::init(const vector<Condition>& allConditionConfig,
+                                       const vector<sp<ConditionTracker>>& allConditionTrackers,
+                                       const unordered_map<string, int>& conditionNameIndexMap,
+                                       vector<bool>& stack) {
+    VLOG("Combiniation condition init() %s", mName.c_str());
+    if (mInitialized) {
+        return true;
+    }
+
+    // mark this node as visited in the recursion stack.
+    stack[mIndex] = true;
+
+    Condition_Combination combinationCondition = allConditionConfig[mIndex].combination();
+
+    if (!combinationCondition.has_operation()) {
+        return false;
+    }
+    mLogicalOperation = combinationCondition.operation();
+
+    if (mLogicalOperation == LogicalOperation::NOT && combinationCondition.condition_size() != 1) {
+        return false;
+    }
+
+    for (string child : combinationCondition.condition()) {
+        auto it = conditionNameIndexMap.find(child);
+
+        if (it == conditionNameIndexMap.end()) {
+            ALOGW("Condition %s not found in the config", child.c_str());
+            return false;
+        }
+
+        int childIndex = it->second;
+        const auto& childTracker = allConditionTrackers[childIndex];
+        // if the child is a visited node in the recursion -> circle detected.
+        if (stack[childIndex]) {
+            ALOGW("Circle detected!!!");
+            return false;
+        }
+
+        bool initChildSucceeded = childTracker->init(allConditionConfig, allConditionTrackers,
+                                                     conditionNameIndexMap, stack);
+
+        if (!initChildSucceeded) {
+            ALOGW("Child initialization failed %s ", child.c_str());
+            return false;
+        } else {
+            ALOGW("Child initialization success %s ", child.c_str());
+        }
+
+        mChildren.push_back(childIndex);
+
+        mTrackerIndex.insert(childTracker->getLogTrackerIndex().begin(),
+                             childTracker->getLogTrackerIndex().end());
+    }
+
+    // unmark this node in the recursion stack.
+    stack[mIndex] = false;
+
+    mInitialized = true;
+
+    return true;
+}
+
+bool CombinationConditionTracker::evaluateCondition(
+        const LogEventWrapper& event, const std::vector<MatchingState>& eventMatcherValues,
+        const std::vector<sp<ConditionTracker>>& mAllConditions,
+        std::vector<ConditionState>& conditionCache, std::vector<bool>& changedCache) {
+    // value is up to date.
+    if (conditionCache[mIndex] != ConditionState::kNotEvaluated) {
+        return false;
+    }
+
+    for (const int childIndex : mChildren) {
+        if (conditionCache[childIndex] == ConditionState::kNotEvaluated) {
+            const sp<ConditionTracker>& child = mAllConditions[childIndex];
+            child->evaluateCondition(event, eventMatcherValues, mAllConditions, conditionCache,
+                                     changedCache);
+        }
+    }
+
+    ConditionState newCondition =
+            evaluateCombinationCondition(mChildren, mLogicalOperation, conditionCache);
+
+    bool changed = (mConditionState != newCondition);
+    mConditionState = newCondition;
+
+    conditionCache[mIndex] = mConditionState;
+
+    changedCache[mIndex] = changed;
+    return changed;
+}
+
+}  // namespace statsd
+}  // namespace os
+}  // namespace android