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// 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 "base/supports_user_data.h"
namespace base {
SupportsUserData::SupportsUserData() {
// Harmless to construct on a different execution sequence to subsequent
// usage.
sequence_checker_.DetachFromSequence();
}
SupportsUserData::Data* SupportsUserData::GetUserData(const void* key) const {
DCHECK(sequence_checker_.CalledOnValidSequence());
// Avoid null keys; they are too vulnerable to collision.
DCHECK(key);
DataMap::const_iterator found = user_data_.find(key);
if (found != user_data_.end())
return found->second.get();
return nullptr;
}
void SupportsUserData::SetUserData(const void* key,
std::unique_ptr<Data> data) {
DCHECK(sequence_checker_.CalledOnValidSequence());
// Avoid null keys; they are too vulnerable to collision.
DCHECK(key);
user_data_[key] = std::move(data);
}
void SupportsUserData::RemoveUserData(const void* key) {
DCHECK(sequence_checker_.CalledOnValidSequence());
user_data_.erase(key);
}
void SupportsUserData::DetachFromSequence() {
sequence_checker_.DetachFromSequence();
}
SupportsUserData::~SupportsUserData() {
DCHECK(sequence_checker_.CalledOnValidSequence() || user_data_.empty());
DataMap local_user_data;
user_data_.swap(local_user_data);
// Now this->user_data_ is empty, and any destructors called transitively from
// the destruction of |local_user_data| will see it that way instead of
// examining a being-destroyed object.
}
} // namespace base