1 /*
2  * Copyright 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 #pragma once
18 
19 #include "tuningfork_internal.h"
20 #include "histogram.h"
21 
22 #include <inttypes.h>
23 #include <vector>
24 #include <map>
25 #include <string>
26 #include <memory>
27 
28 namespace tuningfork {
29 
30 typedef ProtobufSerialization SerializedAnnotation;
31 
32 // A prong holds a histogram for a given annotation and instrument key
33 class Prong {
34 public:
35     InstrumentationKey instrumentation_key_;
36     SerializedAnnotation annotation_;
37     Histogram histogram_;
38     TimePoint last_time_ns_;
39 
40     Prong(InstrumentationKey instrumentation_key = 0,
41           const SerializedAnnotation &annotation = {},
42           const Settings::Histogram& histogram_settings = {})
instrumentation_key_(instrumentation_key)43         : instrumentation_key_(instrumentation_key), annotation_(annotation),
44           last_time_ns_(std::chrono::steady_clock::time_point::min()),
45           histogram_(histogram_settings) {}
46 
Tick(TimePoint t_ns)47     void Tick(TimePoint t_ns) {
48         if (last_time_ns_ != std::chrono::steady_clock::time_point::min())
49             Trace(t_ns - last_time_ns_);
50         last_time_ns_ = t_ns;
51     }
52 
Trace(Duration dt_ns)53     void Trace(Duration dt_ns) {
54         // The histogram stores millisecond values as doubles
55         histogram_.Add(
56             double(std::chrono::duration_cast<std::chrono::nanoseconds>(dt_ns).count()) / 1000000);
57     }
58 
Clear()59     void Clear() {
60         last_time_ns_ = std::chrono::steady_clock::time_point::min();
61         histogram_.Clear();
62     }
63 
Count()64     size_t Count() const {
65         return histogram_.Count();
66     }
67 
68     friend class ClearcutSerializer;
69 };
70 
71 // Simple fixed-size cache
72 class ProngCache {
73     std::vector<std::unique_ptr<Prong>> prongs_;
74 public:
75     ProngCache(size_t size, int max_num_instrumentation_keys,
76                const std::vector<Settings::Histogram>& histogram_settings,
77                const std::function<SerializedAnnotation(uint64_t)>& seralizeId);
78 
79     Prong *Get(uint64_t compound_id);
80 
81     void Clear();
82 
83     friend class ClearcutSerializer;
84 
85 };
86 
87 } // namespace tuningfork {
88