pref_service.cc revision ca12bfac764ba476d6cd062bf1dde12cc64c3f40 
1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "base/prefs/pref_service.h"
6
7#include <algorithm>
8
9#include "base/bind.h"
10#include "base/files/file_path.h"
11#include "base/logging.h"
12#include "base/message_loop/message_loop.h"
13#include "base/metrics/histogram.h"
14#include "base/prefs/default_pref_store.h"
15#include "base/prefs/pref_notifier_impl.h"
16#include "base/prefs/pref_registry.h"
17#include "base/prefs/pref_value_store.h"
18#include "base/stl_util.h"
19#include "base/strings/string_number_conversions.h"
20#include "base/strings/string_util.h"
21#include "base/value_conversions.h"
22#include "build/build_config.h"
23
24namespace {
25
26class ReadErrorHandler : public PersistentPrefStore::ReadErrorDelegate {
27 public:
28  ReadErrorHandler(base::Callback<void(PersistentPrefStore::PrefReadError)> cb)
29      : callback_(cb) {}
30
31  virtual void OnError(PersistentPrefStore::PrefReadError error) OVERRIDE {
32    callback_.Run(error);
33  }
34
35 private:
36  base::Callback<void(PersistentPrefStore::PrefReadError)> callback_;
37};
38
39}  // namespace
40
41PrefService::PrefService(
42    PrefNotifierImpl* pref_notifier,
43    PrefValueStore* pref_value_store,
44    PersistentPrefStore* user_prefs,
45    PrefRegistry* pref_registry,
46    base::Callback<void(PersistentPrefStore::PrefReadError)>
47        read_error_callback,
48    bool async)
49    : pref_notifier_(pref_notifier),
50      pref_value_store_(pref_value_store),
51      pref_registry_(pref_registry),
52      user_pref_store_(user_prefs),
53      read_error_callback_(read_error_callback) {
54  pref_notifier_->SetPrefService(this);
55
56  pref_registry_->SetRegistrationCallback(
57      base::Bind(&PrefService::AddRegisteredPreference,
58                 base::Unretained(this)));
59  AddInitialPreferences();
60
61  InitFromStorage(async);
62}
63
64PrefService::~PrefService() {
65  DCHECK(CalledOnValidThread());
66
67  // Remove our callback, setting a NULL one.
68  pref_registry_->SetRegistrationCallback(PrefRegistry::RegistrationCallback());
69
70  // Reset pointers so accesses after destruction reliably crash.
71  pref_value_store_.reset();
72  pref_registry_ = NULL;
73  user_pref_store_ = NULL;
74  pref_notifier_.reset();
75}
76
77void PrefService::InitFromStorage(bool async) {
78  if (!async) {
79    read_error_callback_.Run(user_pref_store_->ReadPrefs());
80  } else {
81    // Guarantee that initialization happens after this function returned.
82    base::MessageLoop::current()->PostTask(
83        FROM_HERE,
84        base::Bind(&PersistentPrefStore::ReadPrefsAsync,
85                   user_pref_store_.get(),
86                   new ReadErrorHandler(read_error_callback_)));
87  }
88}
89
90bool PrefService::ReloadPersistentPrefs() {
91  return user_pref_store_->ReadPrefs() ==
92             PersistentPrefStore::PREF_READ_ERROR_NONE;
93}
94
95void PrefService::CommitPendingWrite() {
96  DCHECK(CalledOnValidThread());
97  user_pref_store_->CommitPendingWrite();
98}
99
100bool PrefService::GetBoolean(const char* path) const {
101  DCHECK(CalledOnValidThread());
102
103  bool result = false;
104
105  const base::Value* value = GetPreferenceValue(path);
106  if (!value) {
107    NOTREACHED() << "Trying to read an unregistered pref: " << path;
108    return result;
109  }
110  bool rv = value->GetAsBoolean(&result);
111  DCHECK(rv);
112  return result;
113}
114
115int PrefService::GetInteger(const char* path) const {
116  DCHECK(CalledOnValidThread());
117
118  int result = 0;
119
120  const base::Value* value = GetPreferenceValue(path);
121  if (!value) {
122    NOTREACHED() << "Trying to read an unregistered pref: " << path;
123    return result;
124  }
125  bool rv = value->GetAsInteger(&result);
126  DCHECK(rv);
127  return result;
128}
129
130double PrefService::GetDouble(const char* path) const {
131  DCHECK(CalledOnValidThread());
132
133  double result = 0.0;
134
135  const base::Value* value = GetPreferenceValue(path);
136  if (!value) {
137    NOTREACHED() << "Trying to read an unregistered pref: " << path;
138    return result;
139  }
140  bool rv = value->GetAsDouble(&result);
141  DCHECK(rv);
142  return result;
143}
144
145std::string PrefService::GetString(const char* path) const {
146  DCHECK(CalledOnValidThread());
147
148  std::string result;
149
150  const base::Value* value = GetPreferenceValue(path);
151  if (!value) {
152    NOTREACHED() << "Trying to read an unregistered pref: " << path;
153    return result;
154  }
155  bool rv = value->GetAsString(&result);
156  DCHECK(rv);
157  return result;
158}
159
160base::FilePath PrefService::GetFilePath(const char* path) const {
161  DCHECK(CalledOnValidThread());
162
163  base::FilePath result;
164
165  const base::Value* value = GetPreferenceValue(path);
166  if (!value) {
167    NOTREACHED() << "Trying to read an unregistered pref: " << path;
168    return base::FilePath(result);
169  }
170  bool rv = base::GetValueAsFilePath(*value, &result);
171  DCHECK(rv);
172  return result;
173}
174
175bool PrefService::HasPrefPath(const char* path) const {
176  const Preference* pref = FindPreference(path);
177  return pref && !pref->IsDefaultValue();
178}
179
180base::DictionaryValue* PrefService::GetPreferenceValues() const {
181  DCHECK(CalledOnValidThread());
182  base::DictionaryValue* out = new base::DictionaryValue;
183  PrefRegistry::const_iterator i = pref_registry_->begin();
184  for (; i != pref_registry_->end(); ++i) {
185    const base::Value* value = GetPreferenceValue(i->first);
186    DCHECK(value);
187    out->Set(i->first, value->DeepCopy());
188  }
189  return out;
190}
191
192const PrefService::Preference* PrefService::FindPreference(
193    const char* pref_name) const {
194  DCHECK(CalledOnValidThread());
195  PreferenceMap::iterator it = prefs_map_.find(pref_name);
196  if (it != prefs_map_.end())
197    return &(it->second);
198  const base::Value* default_value = NULL;
199  if (!pref_registry_->defaults()->GetValue(pref_name, &default_value))
200    return NULL;
201  it = prefs_map_.insert(
202      std::make_pair(pref_name, Preference(
203          this, pref_name, default_value->GetType()))).first;
204  return &(it->second);
205}
206
207bool PrefService::ReadOnly() const {
208  return user_pref_store_->ReadOnly();
209}
210
211PrefService::PrefInitializationStatus PrefService::GetInitializationStatus()
212    const {
213  if (!user_pref_store_->IsInitializationComplete())
214    return INITIALIZATION_STATUS_WAITING;
215
216  switch (user_pref_store_->GetReadError()) {
217    case PersistentPrefStore::PREF_READ_ERROR_NONE:
218      return INITIALIZATION_STATUS_SUCCESS;
219    case PersistentPrefStore::PREF_READ_ERROR_NO_FILE:
220      return INITIALIZATION_STATUS_CREATED_NEW_PREF_STORE;
221    default:
222      return INITIALIZATION_STATUS_ERROR;
223  }
224}
225
226bool PrefService::IsManagedPreference(const char* pref_name) const {
227  const Preference* pref = FindPreference(pref_name);
228  return pref && pref->IsManaged();
229}
230
231bool PrefService::IsUserModifiablePreference(const char* pref_name) const {
232  const Preference* pref = FindPreference(pref_name);
233  return pref && pref->IsUserModifiable();
234}
235
236const base::DictionaryValue* PrefService::GetDictionary(
237    const char* path) const {
238  DCHECK(CalledOnValidThread());
239
240  const base::Value* value = GetPreferenceValue(path);
241  if (!value) {
242    NOTREACHED() << "Trying to read an unregistered pref: " << path;
243    return NULL;
244  }
245  if (value->GetType() != base::Value::TYPE_DICTIONARY) {
246    NOTREACHED();
247    return NULL;
248  }
249  return static_cast<const base::DictionaryValue*>(value);
250}
251
252const base::Value* PrefService::GetUserPrefValue(const char* path) const {
253  DCHECK(CalledOnValidThread());
254
255  const Preference* pref = FindPreference(path);
256  if (!pref) {
257    NOTREACHED() << "Trying to get an unregistered pref: " << path;
258    return NULL;
259  }
260
261  // Look for an existing preference in the user store. If it doesn't
262  // exist, return NULL.
263  base::Value* value = NULL;
264  if (!user_pref_store_->GetMutableValue(path, &value))
265    return NULL;
266
267  if (!value->IsType(pref->GetType())) {
268    NOTREACHED() << "Pref value type doesn't match registered type.";
269    return NULL;
270  }
271
272  return value;
273}
274
275void PrefService::SetDefaultPrefValue(const char* path,
276                                      base::Value* value) {
277  DCHECK(CalledOnValidThread());
278  pref_registry_->SetDefaultPrefValue(path, value);
279}
280
281const base::Value* PrefService::GetDefaultPrefValue(const char* path) const {
282  DCHECK(CalledOnValidThread());
283  // Lookup the preference in the default store.
284  const base::Value* value = NULL;
285  if (!pref_registry_->defaults()->GetValue(path, &value)) {
286    NOTREACHED() << "Default value missing for pref: " << path;
287    return NULL;
288  }
289  return value;
290}
291
292const base::ListValue* PrefService::GetList(const char* path) const {
293  DCHECK(CalledOnValidThread());
294
295  const base::Value* value = GetPreferenceValue(path);
296  if (!value) {
297    NOTREACHED() << "Trying to read an unregistered pref: " << path;
298    return NULL;
299  }
300  if (value->GetType() != base::Value::TYPE_LIST) {
301    NOTREACHED();
302    return NULL;
303  }
304  return static_cast<const base::ListValue*>(value);
305}
306
307void PrefService::AddPrefObserver(const char* path, PrefObserver* obs) {
308  pref_notifier_->AddPrefObserver(path, obs);
309}
310
311void PrefService::RemovePrefObserver(const char* path, PrefObserver* obs) {
312  pref_notifier_->RemovePrefObserver(path, obs);
313}
314
315void PrefService::AddPrefInitObserver(base::Callback<void(bool)> obs) {
316  pref_notifier_->AddInitObserver(obs);
317}
318
319PrefRegistry* PrefService::DeprecatedGetPrefRegistry() {
320  return pref_registry_.get();
321}
322
323void PrefService::AddInitialPreferences() {
324  for (PrefRegistry::const_iterator it = pref_registry_->begin();
325       it != pref_registry_->end();
326       ++it) {
327    AddRegisteredPreference(it->first.c_str(), it->second);
328  }
329}
330
331// TODO(joi): Once MarkNeedsEmptyValue is gone, we can probably
332// completely get rid of this method. There will be one difference in
333// semantics; currently all registered preferences are stored right
334// away in the prefs_map_, if we remove this they would be stored only
335// opportunistically.
336void PrefService::AddRegisteredPreference(const char* path,
337                                          base::Value* default_value) {
338  DCHECK(CalledOnValidThread());
339
340  // For ListValue and DictionaryValue with non empty default, empty value
341  // for |path| needs to be persisted in |user_pref_store_|. So that
342  // non empty default is not used when user sets an empty ListValue or
343  // DictionaryValue.
344  bool needs_empty_value = false;
345  base::Value::Type orig_type = default_value->GetType();
346  if (orig_type == base::Value::TYPE_LIST) {
347    const base::ListValue* list = NULL;
348    if (default_value->GetAsList(&list) && !list->empty())
349      needs_empty_value = true;
350  } else if (orig_type == base::Value::TYPE_DICTIONARY) {
351    const base::DictionaryValue* dict = NULL;
352    if (default_value->GetAsDictionary(&dict) && !dict->empty())
353      needs_empty_value = true;
354  }
355  if (needs_empty_value)
356    user_pref_store_->MarkNeedsEmptyValue(path);
357}
358
359void PrefService::ClearPref(const char* path) {
360  DCHECK(CalledOnValidThread());
361
362  const Preference* pref = FindPreference(path);
363  if (!pref) {
364    NOTREACHED() << "Trying to clear an unregistered pref: " << path;
365    return;
366  }
367  user_pref_store_->RemoveValue(path);
368}
369
370void PrefService::Set(const char* path, const base::Value& value) {
371  SetUserPrefValue(path, value.DeepCopy());
372}
373
374void PrefService::SetBoolean(const char* path, bool value) {
375  SetUserPrefValue(path, base::Value::CreateBooleanValue(value));
376}
377
378void PrefService::SetInteger(const char* path, int value) {
379  SetUserPrefValue(path, base::Value::CreateIntegerValue(value));
380}
381
382void PrefService::SetDouble(const char* path, double value) {
383  SetUserPrefValue(path, base::Value::CreateDoubleValue(value));
384}
385
386void PrefService::SetString(const char* path, const std::string& value) {
387  SetUserPrefValue(path, base::Value::CreateStringValue(value));
388}
389
390void PrefService::SetFilePath(const char* path, const base::FilePath& value) {
391  SetUserPrefValue(path, base::CreateFilePathValue(value));
392}
393
394void PrefService::SetInt64(const char* path, int64 value) {
395  SetUserPrefValue(path,
396                   base::Value::CreateStringValue(base::Int64ToString(value)));
397}
398
399int64 PrefService::GetInt64(const char* path) const {
400  DCHECK(CalledOnValidThread());
401
402  const base::Value* value = GetPreferenceValue(path);
403  if (!value) {
404    NOTREACHED() << "Trying to read an unregistered pref: " << path;
405    return 0;
406  }
407  std::string result("0");
408  bool rv = value->GetAsString(&result);
409  DCHECK(rv);
410
411  int64 val;
412  base::StringToInt64(result, &val);
413  return val;
414}
415
416void PrefService::SetUint64(const char* path, uint64 value) {
417  SetUserPrefValue(path,
418                   base::Value::CreateStringValue(base::Uint64ToString(value)));
419}
420
421uint64 PrefService::GetUint64(const char* path) const {
422  DCHECK(CalledOnValidThread());
423
424  const base::Value* value = GetPreferenceValue(path);
425  if (!value) {
426    NOTREACHED() << "Trying to read an unregistered pref: " << path;
427    return 0;
428  }
429  std::string result("0");
430  bool rv = value->GetAsString(&result);
431  DCHECK(rv);
432
433  uint64 val;
434  base::StringToUint64(result, &val);
435  return val;
436}
437
438base::Value* PrefService::GetMutableUserPref(const char* path,
439                                             base::Value::Type type) {
440  CHECK(type == base::Value::TYPE_DICTIONARY || type == base::Value::TYPE_LIST);
441  DCHECK(CalledOnValidThread());
442
443  const Preference* pref = FindPreference(path);
444  if (!pref) {
445    NOTREACHED() << "Trying to get an unregistered pref: " << path;
446    return NULL;
447  }
448  if (pref->GetType() != type) {
449    NOTREACHED() << "Wrong type for GetMutableValue: " << path;
450    return NULL;
451  }
452
453  // Look for an existing preference in the user store. If it doesn't
454  // exist or isn't the correct type, create a new user preference.
455  base::Value* value = NULL;
456  if (!user_pref_store_->GetMutableValue(path, &value) ||
457      !value->IsType(type)) {
458    if (type == base::Value::TYPE_DICTIONARY) {
459      value = new base::DictionaryValue;
460    } else if (type == base::Value::TYPE_LIST) {
461      value = new base::ListValue;
462    } else {
463      NOTREACHED();
464    }
465    user_pref_store_->SetValueSilently(path, value);
466  }
467  return value;
468}
469
470void PrefService::ReportUserPrefChanged(const std::string& key) {
471  user_pref_store_->ReportValueChanged(key);
472}
473
474void PrefService::SetUserPrefValue(const char* path, base::Value* new_value) {
475  scoped_ptr<base::Value> owned_value(new_value);
476  DCHECK(CalledOnValidThread());
477
478  const Preference* pref = FindPreference(path);
479  if (!pref) {
480    NOTREACHED() << "Trying to write an unregistered pref: " << path;
481    return;
482  }
483  if (pref->GetType() != new_value->GetType()) {
484    NOTREACHED() << "Trying to set pref " << path
485                 << " of type " << pref->GetType()
486                 << " to value of type " << new_value->GetType();
487    return;
488  }
489
490  user_pref_store_->SetValue(path, owned_value.release());
491}
492
493void PrefService::UpdateCommandLinePrefStore(PrefStore* command_line_store) {
494  pref_value_store_->UpdateCommandLinePrefStore(command_line_store);
495}
496
497///////////////////////////////////////////////////////////////////////////////
498// PrefService::Preference
499
500PrefService::Preference::Preference(const PrefService* service,
501                                    const char* name,
502                                    base::Value::Type type)
503      : name_(name),
504        type_(type),
505        pref_service_(service) {
506  DCHECK(name);
507  DCHECK(service);
508}
509
510const std::string PrefService::Preference::name() const {
511  return name_;
512}
513
514base::Value::Type PrefService::Preference::GetType() const {
515  return type_;
516}
517
518const base::Value* PrefService::Preference::GetValue() const {
519  const base::Value* result= pref_service_->GetPreferenceValue(name_);
520  DCHECK(result) << "Must register pref before getting its value";
521  return result;
522}
523
524const base::Value* PrefService::Preference::GetRecommendedValue() const {
525  DCHECK(pref_service_->FindPreference(name_.c_str())) <<
526      "Must register pref before getting its value";
527
528  const base::Value* found_value = NULL;
529  if (pref_value_store()->GetRecommendedValue(name_, type_, &found_value)) {
530    DCHECK(found_value->IsType(type_));
531    return found_value;
532  }
533
534  // The pref has no recommended value.
535  return NULL;
536}
537
538bool PrefService::Preference::IsManaged() const {
539  return pref_value_store()->PrefValueInManagedStore(name_.c_str());
540}
541
542bool PrefService::Preference::IsRecommended() const {
543  return pref_value_store()->PrefValueFromRecommendedStore(name_.c_str());
544}
545
546bool PrefService::Preference::HasExtensionSetting() const {
547  return pref_value_store()->PrefValueInExtensionStore(name_.c_str());
548}
549
550bool PrefService::Preference::HasUserSetting() const {
551  return pref_value_store()->PrefValueInUserStore(name_.c_str());
552}
553
554bool PrefService::Preference::IsExtensionControlled() const {
555  return pref_value_store()->PrefValueFromExtensionStore(name_.c_str());
556}
557
558bool PrefService::Preference::IsUserControlled() const {
559  return pref_value_store()->PrefValueFromUserStore(name_.c_str());
560}
561
562bool PrefService::Preference::IsDefaultValue() const {
563  return pref_value_store()->PrefValueFromDefaultStore(name_.c_str());
564}
565
566bool PrefService::Preference::IsUserModifiable() const {
567  return pref_value_store()->PrefValueUserModifiable(name_.c_str());
568}
569
570bool PrefService::Preference::IsExtensionModifiable() const {
571  return pref_value_store()->PrefValueExtensionModifiable(name_.c_str());
572}
573
574const base::Value* PrefService::GetPreferenceValue(
575    const std::string& path) const {
576  DCHECK(CalledOnValidThread());
577  const base::Value* default_value = NULL;
578  if (pref_registry_->defaults()->GetValue(path, &default_value)) {
579    const base::Value* found_value = NULL;
580    base::Value::Type default_type = default_value->GetType();
581    if (pref_value_store_->GetValue(path, default_type, &found_value)) {
582      DCHECK(found_value->IsType(default_type));
583      return found_value;
584    } else {
585      // Every registered preference has at least a default value.
586      NOTREACHED() << "no valid value found for registered pref " << path;
587    }
588  }
589
590  return NULL;
591}
592