Move the bits of Prefs where production code has only trivially easy

chrome/common/json_pref_store.cc

Index: chrome/common/json_pref_store.cc
diff --git a/chrome/common/json_pref_store.cc b/chrome/common/json_pref_store.cc
deleted file mode 100644
index ed30346ff048190d9ad004b210f14be3ffca8cf7..0000000000000000000000000000000000000000
--- a/chrome/common/json_pref_store.cc
+++ /dev/null
@@ -1,344 +0,0 @@
-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "chrome/common/json_pref_store.h"
-
-#include <algorithm>
-
-#include "base/bind.h"
-#include "base/callback.h"
-#include "base/file_util.h"
-#include "base/json/json_file_value_serializer.h"
-#include "base/json/json_string_value_serializer.h"
-#include "base/memory/ref_counted.h"
-#include "base/message_loop_proxy.h"
-#include "base/values.h"
-
-namespace {
-
-// Some extensions we'll tack on to copies of the Preferences files.
-const FilePath::CharType* kBadExtension = FILE_PATH_LITERAL("bad");
-
-// Differentiates file loading between origin thread and passed
-// (aka file) thread.
-class FileThreadDeserializer
-    : public base::RefCountedThreadSafe<FileThreadDeserializer> {
- public:
-  FileThreadDeserializer(JsonPrefStore* delegate,
-                         base::MessageLoopProxy* file_loop_proxy)
-      : no_dir_(false),
-        error_(PersistentPrefStore::PREF_READ_ERROR_NONE),
-        delegate_(delegate),
-        file_loop_proxy_(file_loop_proxy),
-        origin_loop_proxy_(base::MessageLoopProxy::current()) {
-  }
-
-  void Start(const FilePath& path) {
-    DCHECK(origin_loop_proxy_->BelongsToCurrentThread());
-    file_loop_proxy_->PostTask(
-        FROM_HERE,
-        base::Bind(&FileThreadDeserializer::ReadFileAndReport,
-                   this, path));
-  }
-
-  // Deserializes JSON on the file thread.
-  void ReadFileAndReport(const FilePath& path) {
-    DCHECK(file_loop_proxy_->BelongsToCurrentThread());
-
-    value_.reset(DoReading(path, &error_, &no_dir_));
-
-    origin_loop_proxy_->PostTask(
-        FROM_HERE,
-        base::Bind(&FileThreadDeserializer::ReportOnOriginThread, this));
-  }
-
-  // Reports deserialization result on the origin thread.
-  void ReportOnOriginThread() {
-    DCHECK(origin_loop_proxy_->BelongsToCurrentThread());
-    delegate_->OnFileRead(value_.release(), error_, no_dir_);
-  }
-
-  static Value* DoReading(const FilePath& path,
-                          PersistentPrefStore::PrefReadError* error,
-                          bool* no_dir) {
-    int error_code;
-    std::string error_msg;
-    JSONFileValueSerializer serializer(path);
-    Value* value = serializer.Deserialize(&error_code, &error_msg);
-    HandleErrors(value, path, error_code, error_msg, error);
-    *no_dir = !file_util::PathExists(path.DirName());
-    return value;
-  }
-
-  static void HandleErrors(const Value* value,
-                           const FilePath& path,
-                           int error_code,
-                           const std::string& error_msg,
-                           PersistentPrefStore::PrefReadError* error);
-
- private:
-  friend class base::RefCountedThreadSafe<FileThreadDeserializer>;
-  ~FileThreadDeserializer() {}
-
-  bool no_dir_;
-  PersistentPrefStore::PrefReadError error_;
-  scoped_ptr<Value> value_;
-  scoped_refptr<JsonPrefStore> delegate_;
-  scoped_refptr<base::MessageLoopProxy> file_loop_proxy_;
-  scoped_refptr<base::MessageLoopProxy> origin_loop_proxy_;
-};
-
-// static
-void FileThreadDeserializer::HandleErrors(
-    const Value* value,
-    const FilePath& path,
-    int error_code,
-    const std::string& error_msg,
-    PersistentPrefStore::PrefReadError* error) {
-  *error = PersistentPrefStore::PREF_READ_ERROR_NONE;
-  if (!value) {
-    DVLOG(1) << "Error while loading JSON file: " << error_msg;
-    switch (error_code) {
-      case JSONFileValueSerializer::JSON_ACCESS_DENIED:
-        *error = PersistentPrefStore::PREF_READ_ERROR_ACCESS_DENIED;
-        break;
-      case JSONFileValueSerializer::JSON_CANNOT_READ_FILE:
-        *error = PersistentPrefStore::PREF_READ_ERROR_FILE_OTHER;
-        break;
-      case JSONFileValueSerializer::JSON_FILE_LOCKED:
-        *error = PersistentPrefStore::PREF_READ_ERROR_FILE_LOCKED;
-        break;
-      case JSONFileValueSerializer::JSON_NO_SUCH_FILE:
-        *error = PersistentPrefStore::PREF_READ_ERROR_NO_FILE;
-        break;
-      default:
-        *error = PersistentPrefStore::PREF_READ_ERROR_JSON_PARSE;
-        // JSON errors indicate file corruption of some sort.
-        // Since the file is corrupt, move it to the side and continue with
-        // empty preferences.  This will result in them losing their settings.
-        // We keep the old file for possible support and debugging assistance
-        // as well as to detect if they're seeing these errors repeatedly.
-        // TODO(erikkay) Instead, use the last known good file.
-        FilePath bad = path.ReplaceExtension(kBadExtension);
-
-        // If they've ever had a parse error before, put them in another bucket.
-        // TODO(erikkay) if we keep this error checking for very long, we may
-        // want to differentiate between recent and long ago errors.
-        if (file_util::PathExists(bad))
-          *error = PersistentPrefStore::PREF_READ_ERROR_JSON_REPEAT;
-        file_util::Move(path, bad);
-        break;
-    }
-  } else if (!value->IsType(Value::TYPE_DICTIONARY)) {
-    *error = PersistentPrefStore::PREF_READ_ERROR_JSON_TYPE;
-  }
-}
-
-}  // namespace
-
-JsonPrefStore::JsonPrefStore(const FilePath& filename,
-                             base::MessageLoopProxy* file_message_loop_proxy)
-    : path_(filename),
-      file_message_loop_proxy_(file_message_loop_proxy),
-      prefs_(new DictionaryValue()),
-      read_only_(false),
-      writer_(filename, file_message_loop_proxy),
-      error_delegate_(NULL),
-      initialized_(false),
-      read_error_(PREF_READ_ERROR_OTHER) {
-}
-
-PrefStore::ReadResult JsonPrefStore::GetValue(const std::string& key,
-                                              const Value** result) const {
-  Value* tmp = NULL;
-  if (prefs_->Get(key, &tmp)) {
-    if (result)
-      *result = tmp;
-    return READ_OK;
-  }
-  return READ_NO_VALUE;
-}
-
-void JsonPrefStore::AddObserver(PrefStore::Observer* observer) {
-  observers_.AddObserver(observer);
-}
-
-void JsonPrefStore::RemoveObserver(PrefStore::Observer* observer) {
-  observers_.RemoveObserver(observer);
-}
-
-size_t JsonPrefStore::NumberOfObservers() const {
-  return observers_.size();
-}
-
-bool JsonPrefStore::IsInitializationComplete() const {
-  return initialized_;
-}
-
-PrefStore::ReadResult JsonPrefStore::GetMutableValue(const std::string& key,
-                                                     Value** result) {
-  return prefs_->Get(key, result) ? READ_OK : READ_NO_VALUE;
-}
-
-void JsonPrefStore::SetValue(const std::string& key, Value* value) {
-  DCHECK(value);
-  scoped_ptr<Value> new_value(value);
-  Value* old_value = NULL;
-  prefs_->Get(key, &old_value);
-  if (!old_value || !value->Equals(old_value)) {
-    prefs_->Set(key, new_value.release());
-    ReportValueChanged(key);
-  }
-}
-
-void JsonPrefStore::SetValueSilently(const std::string& key, Value* value) {
-  DCHECK(value);
-  scoped_ptr<Value> new_value(value);
-  Value* old_value = NULL;
-  prefs_->Get(key, &old_value);
-  if (!old_value || !value->Equals(old_value)) {
-    prefs_->Set(key, new_value.release());
-    if (!read_only_)
-      writer_.ScheduleWrite(this);
-  }
-}
-
-void JsonPrefStore::RemoveValue(const std::string& key) {
-  if (prefs_->Remove(key, NULL))
-    ReportValueChanged(key);
-}
-
-void JsonPrefStore::MarkNeedsEmptyValue(const std::string& key) {
-  keys_need_empty_value_.insert(key);
-}
-
-bool JsonPrefStore::ReadOnly() const {
-  return read_only_;
-}
-
-PersistentPrefStore::PrefReadError JsonPrefStore::GetReadError() const {
-  return read_error_;
-}
-
-PersistentPrefStore::PrefReadError JsonPrefStore::ReadPrefs() {
-  if (path_.empty()) {
-    OnFileRead(NULL, PREF_READ_ERROR_FILE_NOT_SPECIFIED, false);
-    return PREF_READ_ERROR_FILE_NOT_SPECIFIED;
-  }
-
-  PrefReadError error;
-  bool no_dir;
-  Value* value = FileThreadDeserializer::DoReading(path_, &error, &no_dir);
-  OnFileRead(value, error, no_dir);
-  return error;
-}
-
-void JsonPrefStore::ReadPrefsAsync(ReadErrorDelegate *error_delegate) {
-  initialized_ = false;
-  error_delegate_.reset(error_delegate);
-  if (path_.empty()) {
-    OnFileRead(NULL, PREF_READ_ERROR_FILE_NOT_SPECIFIED, false);
-    return;
-  }
-
-  // Start async reading of the preferences file. It will delete itself
-  // in the end.
-  scoped_refptr<FileThreadDeserializer> deserializer(
-      new FileThreadDeserializer(this, file_message_loop_proxy_.get()));
-  deserializer->Start(path_);
-}
-
-void JsonPrefStore::CommitPendingWrite() {
-  if (writer_.HasPendingWrite() && !read_only_)
-    writer_.DoScheduledWrite();
-}
-
-void JsonPrefStore::ReportValueChanged(const std::string& key) {
-  FOR_EACH_OBSERVER(PrefStore::Observer, observers_, OnPrefValueChanged(key));
-  if (!read_only_)
-    writer_.ScheduleWrite(this);
-}
-
-void JsonPrefStore::OnFileRead(Value* value_owned,
-                               PersistentPrefStore::PrefReadError error,
-                               bool no_dir) {
-  scoped_ptr<Value> value(value_owned);
-  read_error_ = error;
-
-  if (no_dir) {
-    FOR_EACH_OBSERVER(PrefStore::Observer,
-                      observers_,
-                      OnInitializationCompleted(false));
-    return;
-  }
-
-  initialized_ = true;
-
-  switch (error) {
-    case PREF_READ_ERROR_ACCESS_DENIED:
-    case PREF_READ_ERROR_FILE_OTHER:
-    case PREF_READ_ERROR_FILE_LOCKED:
-    case PREF_READ_ERROR_JSON_TYPE:
-    case PREF_READ_ERROR_FILE_NOT_SPECIFIED:
-      read_only_ = true;
-      break;
-    case PREF_READ_ERROR_NONE:
-      DCHECK(value.get());
-      prefs_.reset(static_cast<DictionaryValue*>(value.release()));
-      break;
-    case PREF_READ_ERROR_NO_FILE:
-      // If the file just doesn't exist, maybe this is first run.  In any case
-      // there's no harm in writing out default prefs in this case.
-      break;
-    case PREF_READ_ERROR_JSON_PARSE:
-    case PREF_READ_ERROR_JSON_REPEAT:
-      break;
-    default:
-      NOTREACHED() << "Unknown error: " << error;
-  }
-
-  if (error_delegate_.get() && error != PREF_READ_ERROR_NONE)
-    error_delegate_->OnError(error);
-
-  FOR_EACH_OBSERVER(PrefStore::Observer,
-                    observers_,
-                    OnInitializationCompleted(true));
-}
-
-JsonPrefStore::~JsonPrefStore() {
-  CommitPendingWrite();
-}
-
-bool JsonPrefStore::SerializeData(std::string* output) {
-  // TODO(tc): Do we want to prune webkit preferences that match the default
-  // value?
-  JSONStringValueSerializer serializer(output);
-  serializer.set_pretty_print(true);
-  scoped_ptr<DictionaryValue> copy(prefs_->DeepCopyWithoutEmptyChildren());
-
-  // Iterates |keys_need_empty_value_| and if the key exists in |prefs_|,
-  // ensure its empty ListValue or DictonaryValue is preserved.
-  for (std::set<std::string>::const_iterator
-       it = keys_need_empty_value_.begin();
-       it != keys_need_empty_value_.end();
-       ++it) {
-    const std::string& key = *it;
-
-    base::Value* value = NULL;
-    if (!prefs_->Get(key, &value))
-      continue;
-
-    if (value->IsType(base::Value::TYPE_LIST)) {
-      const base::ListValue* list = NULL;
-      if (value->GetAsList(&list) && list->empty())
-        copy->Set(key, new base::ListValue);
-    } else if (value->IsType(base::Value::TYPE_DICTIONARY)) {
-      const base::DictionaryValue* dict = NULL;
-      if (value->GetAsDictionary(&dict) && dict->empty())
-        copy->Set(key, new base::DictionaryValue);
-    }
-  }
-
-  return serializer.Serialize(*(copy.get()));
-}