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_TRACED_PROBES_PROBES_DATA_SOURCE_H_
18 #define SRC_TRACED_PROBES_PROBES_DATA_SOURCE_H_
19 
20 #include <functional>
21 
22 #include "perfetto/base/logging.h"
23 #include "perfetto/ext/tracing/core/basic_types.h"
24 #include "perfetto/tracing/core/forward_decls.h"
25 
26 namespace perfetto {
27 
28 // Base class for all data sources in traced_probes.
29 class ProbesDataSource {
30  public:
31   // Static properties for a data source. Needs to be available before
32   // instantiating each data source. It must have static lifetime.
33   struct Descriptor {
34     enum Flags : uint32_t {
35       kFlagsNone = 0,
36       kHandlesIncrementalState = 1 << 0,
37     };
38     const char* const name;
39     uint32_t flags;
40   };
41 
42   ProbesDataSource(TracingSessionID, const Descriptor*);
43   virtual ~ProbesDataSource();
44 
45   virtual void Start() = 0;
46   virtual void Flush(FlushRequestID, std::function<void()> callback) = 0;
47 
48   // Only data sources that opt in via DataSourceDescriptor should receive this
49   // call.
ClearIncrementalState()50   virtual void ClearIncrementalState() {
51     PERFETTO_ELOG(
52         "ClearIncrementalState received by data source that doesn't provide "
53         "its own implementation.");
54   }
55 
56   const TracingSessionID tracing_session_id;
57   const Descriptor* const descriptor;
58   bool started = false;  // Set by probes_producer.cc.
59 
60  private:
61   ProbesDataSource(const ProbesDataSource&) = delete;
62   ProbesDataSource& operator=(const ProbesDataSource&) = delete;
63 };
64 
65 }  // namespace perfetto
66 
67 #endif  // SRC_TRACED_PROBES_PROBES_DATA_SOURCE_H_
68