1 /*
2  * Copyright (C) 2018 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 SRC_TRACE_PROCESSOR_SQL_STATS_TABLE_H_
18 #define SRC_TRACE_PROCESSOR_SQL_STATS_TABLE_H_
19 
20 #include <limits>
21 #include <memory>
22 
23 #include "src/trace_processor/table.h"
24 
25 namespace perfetto {
26 namespace trace_processor {
27 
28 class QueryConstraints;
29 class TraceStorage;
30 
31 // A virtual table that allows to introspect performances of the SQL engine
32 // for the kMaxLogEntries queries.
33 class SqlStatsTable : public Table {
34  public:
35   enum Column {
36     kQuery = 0,
37     kTimeQueued = 1,
38     kTimeStarted = 2,
39     kTimeFirstNext = 3,
40     kTimeEnded = 4,
41   };
42 
43   // Implementation of the SQLite cursor interface.
44   class Cursor : public Table::Cursor {
45    public:
46     Cursor(SqlStatsTable* storage);
47     ~Cursor() override;
48 
49     // Implementation of Table::Cursor.
50     int Filter(const QueryConstraints&, sqlite3_value**) override;
51     int Next() override;
52     int Eof() override;
53     int Column(sqlite3_context*, int N) override;
54 
55    private:
56     Cursor(Cursor&) = delete;
57     Cursor& operator=(const Cursor&) = delete;
58 
59     Cursor(Cursor&&) noexcept = default;
60     Cursor& operator=(Cursor&&) = default;
61 
62     size_t row_ = 0;
63     size_t num_rows_ = 0;
64     const TraceStorage* storage_ = nullptr;
65     SqlStatsTable* table_ = nullptr;
66   };
67 
68   SqlStatsTable(sqlite3*, const TraceStorage* storage);
69 
70   static void RegisterTable(sqlite3* db, const TraceStorage* storage);
71 
72   // Table implementation.
73   base::Optional<Table::Schema> Init(int, const char* const*) override;
74   std::unique_ptr<Table::Cursor> CreateCursor() override;
75   int BestIndex(const QueryConstraints&, BestIndexInfo*) override;
76 
77  private:
78   const TraceStorage* const storage_;
79 };
80 
81 }  // namespace trace_processor
82 }  // namespace perfetto
83 
84 #endif  // SRC_TRACE_PROCESSOR_SQL_STATS_TABLE_H_
85