1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
3 /* This Source Code Form is subject to the terms of the Mozilla Public
4 * License, v. 2.0. If a copy of the MPL was not distributed with this
5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6
7 #include "LogModulePrefWatcher.h"
8
9 #include "mozilla/Logging.h"
10 #include "mozilla/Preferences.h"
11 #include "mozilla/Services.h"
12 #include "nsIObserverService.h"
13 #include "nsMemory.h"
14 #include "nsString.h"
15 #include "nsXULAppAPI.h"
16 #include "base/process_util.h"
17
18 static const char kLoggingPrefPrefix[] = "logging.";
19 static const char kLoggingConfigPrefPrefix[] = "logging.config";
20 static const int kLoggingConfigPrefixLen = sizeof(kLoggingConfigPrefPrefix) - 1;
21 static const char kLoggingPrefClearOnStartup[] =
22 "logging.config.clear_on_startup";
23 static const char kLoggingPrefLogFile[] = "logging.config.LOG_FILE";
24 static const char kLoggingPrefAddTimestamp[] = "logging.config.add_timestamp";
25 static const char kLoggingPrefSync[] = "logging.config.sync";
26
27 namespace mozilla {
28
NS_IMPL_ISUPPORTS(LogModulePrefWatcher,nsIObserver)29 NS_IMPL_ISUPPORTS(LogModulePrefWatcher, nsIObserver)
30
31 /**
32 * Resets all the preferences in the logging. branch
33 * This is needed because we may crash while logging, and this would cause us
34 * to log after restarting as well.
35 *
36 * If logging after restart is desired, set the logging.config.clear_on_startup
37 * pref to false, or use the MOZ_LOG_FILE and MOZ_LOG_MODULES env vars.
38 */
39 static void ResetExistingPrefs() {
40 nsTArray<nsCString> names;
41 nsresult rv =
42 Preferences::GetRootBranch()->GetChildList(kLoggingPrefPrefix, names);
43 if (NS_SUCCEEDED(rv)) {
44 for (auto& name : names) {
45 // Clearing the pref will cause it to reload, thus resetting the log level
46 Preferences::ClearUser(name.get());
47 }
48 }
49 }
50
51 /**
52 * Loads the log level from the given pref and updates the corresponding
53 * LogModule.
54 */
LoadPrefValue(const char * aName)55 static void LoadPrefValue(const char* aName) {
56 LogLevel logLevel = LogLevel::Disabled;
57
58 nsresult rv;
59 int32_t prefLevel = 0;
60 nsAutoCString prefValue;
61
62 if (strncmp(aName, kLoggingConfigPrefPrefix, kLoggingConfigPrefixLen) == 0) {
63 nsAutoCString prefName(aName);
64
65 if (prefName.EqualsLiteral(kLoggingPrefLogFile)) {
66 rv = Preferences::GetCString(aName, prefValue);
67 // The pref was reset. Clear the user file.
68 if (NS_FAILED(rv) || prefValue.IsEmpty()) {
69 LogModule::SetLogFile(nullptr);
70 return;
71 }
72
73 // If the pref value doesn't have a PID placeholder, append it to the end.
74 if (!strstr(prefValue.get(), MOZ_LOG_PID_TOKEN)) {
75 prefValue.AppendLiteral(MOZ_LOG_PID_TOKEN);
76 }
77
78 LogModule::SetLogFile(prefValue.BeginReading());
79 } else if (prefName.EqualsLiteral(kLoggingPrefAddTimestamp)) {
80 bool addTimestamp = Preferences::GetBool(aName, false);
81 LogModule::SetAddTimestamp(addTimestamp);
82 } else if (prefName.EqualsLiteral(kLoggingPrefSync)) {
83 bool sync = Preferences::GetBool(aName, false);
84 LogModule::SetIsSync(sync);
85 }
86 return;
87 }
88
89 if (Preferences::GetInt(aName, &prefLevel) == NS_OK) {
90 logLevel = ToLogLevel(prefLevel);
91 } else if (Preferences::GetCString(aName, prefValue) == NS_OK) {
92 if (prefValue.LowerCaseEqualsLiteral("error")) {
93 logLevel = LogLevel::Error;
94 } else if (prefValue.LowerCaseEqualsLiteral("warning")) {
95 logLevel = LogLevel::Warning;
96 } else if (prefValue.LowerCaseEqualsLiteral("info")) {
97 logLevel = LogLevel::Info;
98 } else if (prefValue.LowerCaseEqualsLiteral("debug")) {
99 logLevel = LogLevel::Debug;
100 } else if (prefValue.LowerCaseEqualsLiteral("verbose")) {
101 logLevel = LogLevel::Verbose;
102 }
103 }
104
105 const char* moduleName = aName + strlen(kLoggingPrefPrefix);
106 LogModule::Get(moduleName)->SetLevel(logLevel);
107 }
108
LoadExistingPrefs()109 static void LoadExistingPrefs() {
110 nsIPrefBranch* root = Preferences::GetRootBranch();
111 if (!root) {
112 return;
113 }
114
115 nsTArray<nsCString> names;
116 nsresult rv = root->GetChildList(kLoggingPrefPrefix, names);
117 if (NS_SUCCEEDED(rv)) {
118 for (auto& name : names) {
119 LoadPrefValue(name.get());
120 }
121 }
122 }
123
124 LogModulePrefWatcher::LogModulePrefWatcher() = default;
125
RegisterPrefWatcher()126 void LogModulePrefWatcher::RegisterPrefWatcher() {
127 RefPtr<LogModulePrefWatcher> prefWatcher = new LogModulePrefWatcher();
128 Preferences::AddStrongObserver(prefWatcher, kLoggingPrefPrefix);
129
130 nsCOMPtr<nsIObserverService> observerService =
131 mozilla::services::GetObserverService();
132 if (observerService && XRE_IsParentProcess()) {
133 observerService->AddObserver(prefWatcher,
134 "browser-delayed-startup-finished", false);
135 }
136
137 LoadExistingPrefs();
138 }
139
140 NS_IMETHODIMP
Observe(nsISupports * aSubject,const char * aTopic,const char16_t * aData)141 LogModulePrefWatcher::Observe(nsISupports* aSubject, const char* aTopic,
142 const char16_t* aData) {
143 if (strcmp(NS_PREFBRANCH_PREFCHANGE_TOPIC_ID, aTopic) == 0) {
144 NS_LossyConvertUTF16toASCII prefName(aData);
145 LoadPrefValue(prefName.get());
146 } else if (strcmp("browser-delayed-startup-finished", aTopic) == 0) {
147 bool clear = Preferences::GetBool(kLoggingPrefClearOnStartup, true);
148 if (clear) {
149 ResetExistingPrefs();
150 }
151 nsCOMPtr<nsIObserverService> observerService =
152 mozilla::services::GetObserverService();
153 if (observerService) {
154 observerService->RemoveObserver(this, "browser-delayed-startup-finished");
155 }
156 }
157
158 return NS_OK;
159 }
160
161 } // namespace mozilla
162