chromium/storage/browser/blob/blob_data_handle.h

// Copyright 2013 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef STORAGE_BROWSER_BLOB_BLOB_DATA_HANDLE_H_
#define STORAGE_BROWSER_BLOB_BLOB_DATA_HANDLE_H_

#include <limits>
#include <memory>
#include <string>

#include "base/component_export.h"
#include "base/functional/callback_forward.h"
#include "base/memory/ref_counted.h"
#include "base/memory/weak_ptr.h"
#include "base/task/sequenced_task_runner_helpers.h"
#include "storage/browser/blob/blob_storage_constants.h"

namespace base {
class SequencedTaskRunner;
}

namespace storage {

class BlobDataSnapshot;
class BlobReader;
class BlobStorageContext;

// BlobDataHandle ensures that the underlying blob (keyed by the uuid) remains
// in the BlobStorageContext's collection while this object is alive. Anything
// that needs to keep a blob alive needs to store this handle.
// When the blob data itself is needed, clients must call the CreateSnapshot()
// method on the IO thread to create a snapshot of the blob data.  This snapshot
// is not intended to be persisted, and serves to ensure that the backing
// resources remain around for the duration of reading the blob.  This snapshot
// can be read on any thread, but it must be destructed on the IO thread.
// This object has delete semantics and may be deleted on any thread.
class COMPONENT_EXPORT(STORAGE_BROWSER) BlobDataHandle { … };

}  // namespace storage

#endif  // STORAGE_BROWSER_BLOB_BLOB_DATA_HANDLE_H_