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      1 /*
      2  * Copyright (C) 2017 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include "Log.h"
     18 
     19 #include "CombinationLogMatchingTracker.h"
     20 #include "matchers/matcher_util.h"
     21 
     22 namespace android {
     23 namespace os {
     24 namespace statsd {
     25 
     26 using std::set;
     27 using std::string;
     28 using std::unique_ptr;
     29 using std::unordered_map;
     30 using std::vector;
     31 
     32 CombinationLogMatchingTracker::CombinationLogMatchingTracker(const int64_t& id, const int index)
     33     : LogMatchingTracker(id, index) {
     34 }
     35 
     36 CombinationLogMatchingTracker::~CombinationLogMatchingTracker() {
     37 }
     38 
     39 bool CombinationLogMatchingTracker::init(const vector<AtomMatcher>& allLogMatchers,
     40                                          const vector<sp<LogMatchingTracker>>& allTrackers,
     41                                          const unordered_map<int64_t, int>& matcherMap,
     42                                          vector<bool>& stack) {
     43     if (mInitialized) {
     44         return true;
     45     }
     46 
     47     // mark this node as visited in the recursion stack.
     48     stack[mIndex] = true;
     49 
     50     AtomMatcher_Combination matcher = allLogMatchers[mIndex].combination();
     51 
     52     // LogicalOperation is missing in the config
     53     if (!matcher.has_operation()) {
     54         return false;
     55     }
     56 
     57     mLogicalOperation = matcher.operation();
     58 
     59     if (mLogicalOperation == LogicalOperation::NOT && matcher.matcher_size() != 1) {
     60         return false;
     61     }
     62 
     63     for (const auto& child : matcher.matcher()) {
     64         auto pair = matcherMap.find(child);
     65         if (pair == matcherMap.end()) {
     66             ALOGW("Matcher %lld not found in the config", (long long)child);
     67             return false;
     68         }
     69 
     70         int childIndex = pair->second;
     71 
     72         // if the child is a visited node in the recursion -> circle detected.
     73         if (stack[childIndex]) {
     74             ALOGE("Circle detected in matcher config");
     75             return false;
     76         }
     77 
     78         if (!allTrackers[childIndex]->init(allLogMatchers, allTrackers, matcherMap, stack)) {
     79             ALOGW("child matcher init failed %lld", (long long)child);
     80             return false;
     81         }
     82 
     83         mChildren.push_back(childIndex);
     84 
     85         const set<int>& childTagIds = allTrackers[childIndex]->getAtomIds();
     86         mAtomIds.insert(childTagIds.begin(), childTagIds.end());
     87     }
     88 
     89     mInitialized = true;
     90     // unmark this node in the recursion stack.
     91     stack[mIndex] = false;
     92     return true;
     93 }
     94 
     95 void CombinationLogMatchingTracker::onLogEvent(const LogEvent& event,
     96                                                const vector<sp<LogMatchingTracker>>& allTrackers,
     97                                                vector<MatchingState>& matcherResults) {
     98     // this event has been processed.
     99     if (matcherResults[mIndex] != MatchingState::kNotComputed) {
    100         return;
    101     }
    102 
    103     if (mAtomIds.find(event.GetTagId()) == mAtomIds.end()) {
    104         matcherResults[mIndex] = MatchingState::kNotMatched;
    105         return;
    106     }
    107 
    108     // evaluate children matchers if they haven't been evaluated.
    109     for (const int childIndex : mChildren) {
    110         if (matcherResults[childIndex] == MatchingState::kNotComputed) {
    111             const sp<LogMatchingTracker>& child = allTrackers[childIndex];
    112             child->onLogEvent(event, allTrackers, matcherResults);
    113         }
    114     }
    115 
    116     bool matched = combinationMatch(mChildren, mLogicalOperation, matcherResults);
    117     matcherResults[mIndex] = matched ? MatchingState::kMatched : MatchingState::kNotMatched;
    118 }
    119 
    120 }  // namespace statsd
    121 }  // namespace os
    122 }  // namespace android
    123