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 #ifndef LOG_MATCHING_TRACKER_H
18 #define LOG_MATCHING_TRACKER_H
19 
20 #include "frameworks/base/cmds/statsd/src/statsd_config.pb.h"
21 #include "logd/LogEvent.h"
22 #include "matchers/matcher_util.h"
23 
24 #include <utils/RefBase.h>
25 
26 #include <set>
27 #include <unordered_map>
28 #include <vector>
29 
30 namespace android {
31 namespace os {
32 namespace statsd {
33 
34 class LogMatchingTracker : public virtual RefBase {
35 public:
LogMatchingTracker(const int64_t & id,const int index)36     LogMatchingTracker(const int64_t& id, const int index)
37         : mId(id), mIndex(index), mInitialized(false){};
38 
~LogMatchingTracker()39     virtual ~LogMatchingTracker(){};
40 
41     // Initialize this LogMatchingTracker.
42     // allLogMatchers: the list of the AtomMatcher proto config. This is needed because we don't
43     //                 store the proto object in memory. We only need it during initilization.
44     // allTrackers: the list of the LogMatchingTracker objects. It's a one-to-one mapping with
45     //              allLogMatchers. This is needed because the initialization is done recursively
46     //              for CombinationLogMatchingTrackers using DFS.
47     // stack: a bit map to record which matcher has been visited on the stack. This is for detecting
48     //        circle dependency.
49     virtual bool init(const std::vector<AtomMatcher>& allLogMatchers,
50                       const std::vector<sp<LogMatchingTracker>>& allTrackers,
51                       const std::unordered_map<int64_t, int>& matcherMap,
52                       std::vector<bool>& stack) = 0;
53 
54     // Called when a log event comes.
55     // event: the log event.
56     // allTrackers: the list of all LogMatchingTrackers. This is needed because the log processing
57     //              is done recursively.
58     // matcherResults: The cached results for all matchers for this event. Parent matchers can
59     //                 directly access the children's matching results if they have been evaluated.
60     //                 Otherwise, call children matchers' onLogEvent.
61     virtual void onLogEvent(const LogEvent& event,
62                             const std::vector<sp<LogMatchingTracker>>& allTrackers,
63                             std::vector<MatchingState>& matcherResults) = 0;
64 
65     // Get the tagIds that this matcher cares about. The combined collection is stored
66     // in MetricMananger, so that we can pass any LogEvents that are not interest of us. It uses
67     // some memory but hopefully it can save us much CPU time when there is flood of events.
getAtomIds()68     virtual const std::set<int>& getAtomIds() const {
69         return mAtomIds;
70     }
71 
getId()72     const int64_t& getId() const {
73         return mId;
74     }
75 
76 protected:
77     // Name of this matching. We don't really need the name, but it makes log message easy to debug.
78     const int64_t mId;
79 
80     // Index of this LogMatchingTracker in MetricsManager's container.
81     const int mIndex;
82 
83     // Whether this LogMatchingTracker has been properly initialized.
84     bool mInitialized;
85 
86     // The collection of the event tag ids that this LogMatchingTracker cares. So we can quickly
87     // return kNotMatched when we receive an event with an id not in the list. This is especially
88     // useful when we have a complex CombinationLogMatcherTracker.
89     std::set<int> mAtomIds;
90 };
91 
92 }  // namespace statsd
93 }  // namespace os
94 }  // namespace android
95 
96 #endif  // LOG_MATCHING_TRACKER_H
97