1 //
2 // Copyright (C) 2015 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 UPDATE_ENGINE_METRICS_UTILS_H_
18 #define UPDATE_ENGINE_METRICS_UTILS_H_
19 
20 #include <chrono>
21 #include <string>
22 #include <string_view>
23 #include <type_traits>
24 #include <utility>
25 
26 #include <base/time/time.h>
27 
28 #include "update_engine/common/clock_interface.h"
29 #include "update_engine/common/connection_utils.h"
30 #include "update_engine/common/error_code.h"
31 #include "update_engine/common/metrics_constants.h"
32 #include "update_engine/common/metrics_reporter_interface.h"
33 #include "update_engine/common/prefs_interface.h"
34 
35 namespace chromeos_update_engine {
36 
37 namespace metrics_utils {
38 
39 // Transforms a ErrorCode value into a metrics::DownloadErrorCode.
40 // This obviously only works for errors related to downloading so if |code|
41 // is e.g. |ErrorCode::kFilesystemCopierError| then
42 // |kDownloadErrorCodeInputMalformed| is returned.
43 metrics::DownloadErrorCode GetDownloadErrorCode(ErrorCode code);
44 
45 // Transforms a ErrorCode value into a metrics::AttemptResult.
46 //
47 // If metrics::AttemptResult::kPayloadDownloadError is returned, you
48 // can use utils::GetDownloadError() to get more detail.
49 metrics::AttemptResult GetAttemptResult(ErrorCode code);
50 
51 // Calculates the internet connection type given |type| and |tethering|.
52 metrics::ConnectionType GetConnectionType(ConnectionType type,
53                                           ConnectionTethering tethering);
54 
55 // Returns the persisted value from prefs for the given key. It also
56 // validates that the value returned is non-negative.
57 int64_t GetPersistedValue(std::string_view key, PrefsInterface* prefs);
58 
59 // Persists the reboot count of the update attempt to |kPrefsNumReboots|.
60 void SetNumReboots(int64_t num_reboots, PrefsInterface* prefs);
61 
62 // Persists the payload attempt number to |kPrefsPayloadAttemptNumber|.
63 void SetPayloadAttemptNumber(int64_t payload_attempt_number,
64                              PrefsInterface* prefs);
65 
66 // Persists the finished time of an update to the |kPrefsSystemUpdatedMarker|.
67 void SetSystemUpdatedMarker(ClockInterface* clock, PrefsInterface* prefs);
68 
69 // Persists the start monotonic time of an update to
70 // |kPrefsUpdateTimestampStart|.
71 void SetUpdateTimestampStart(const base::Time& update_start_time,
72                              PrefsInterface* prefs);
73 
74 // Persists the start boot time of an update to
75 // |kPrefsUpdateBootTimestampStart|.
76 void SetUpdateBootTimestampStart(const base::Time& update_start_boot_time,
77                                  PrefsInterface* prefs);
78 
79 // Called at program startup if the device booted into a new update.
80 // The |time_to_reboot| parameter contains the (monotonic-clock) duration
81 // from when the update successfully completed (the value in
82 // |kPrefsSystemUpdatedMarker|) until the device was booted into the update
83 // (current monotonic-clock time).
84 bool LoadAndReportTimeToReboot(MetricsReporterInterface* metrics_reporter,
85                                PrefsInterface* prefs,
86                                ClockInterface* clock);
87 
88 template <typename T>
89 class PersistedValue {
90  public:
PersistedValue(std::string_view key,PrefsInterface * prefs)91   PersistedValue(std::string_view key, PrefsInterface* prefs)
92       : key_(key), prefs_(prefs) {
93     val_ = metrics_utils::GetPersistedValue(key, prefs);
94   }
~PersistedValue()95   ~PersistedValue() { Flush(true); }
Delete()96   void Delete() {
97     val_ = {};
98     prefs_->Delete(key_);
99   }
get()100   T get() const { return val_; }
101   using clock = std::chrono::system_clock;
102   using time_point = clock::time_point;
103   // prefix increment
104   PersistedValue<T>& operator++() {
105     ++val_;
106     Flush();
107     return *this;
108   }
109   PersistedValue<T>& operator--() {
110     --val_;
111     Flush();
112     return *this;
113   }
114   PersistedValue<T>& operator+=(T&& t) {
115     val_ += std::forward<T>(t);
116     Flush();
117     return *this;
118   }
119   PersistedValue<T>& operator-=(T&& t) {
120     val_ -= std::forward<T>(t);
121     Flush();
122     return *this;
123   }
124   PersistedValue<T>& operator=(T&& t) {
125     val_ = std::forward<T>(t);
126     Flush();
127     return *this;
128   }
129   void Flush(bool force = false) {
130     auto now = clock::now();
131     if (now - last_save_ > metrics::kMetricFlushInterval || force) {
132       last_save_ = now;
133       if (std::is_integral_v<T>) {
134         prefs_->SetInt64(key_, val_);
135       } else if (std::is_same_v<T, bool>) {
136         prefs_->SetBoolean(key_, val_);
137       } else {
138         auto value = std::to_string(val_);
139         prefs_->SetString(key_, value);
140       }
141     }
142   }
143 
144  private:
145   const std::string_view key_;
146   PrefsInterface* prefs_;
147   T val_;
148   time_point last_save_{};
149 };
150 
151 }  // namespace metrics_utils
152 }  // namespace chromeos_update_engine
153 
154 #endif  // UPDATE_ENGINE_METRICS_UTILS_H_
155