components/reporting/resources/resource_interface.h

// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_REPORTING_RESOURCES_RESOURCE_INTERFACE_H_
#define COMPONENTS_REPORTING_RESOURCES_RESOURCE_INTERFACE_H_

#include <cstdint>

#include "base/memory/ref_counted.h"
#include "base/memory/scoped_refptr.h"
#include "third_party/abseil-cpp/absl/types/optional.h"

namespace reporting {

// Interface to resources management by Storage module.
// Must be implemented by the caller base on the platform limitations.
// All APIs are non-blocking.
class ResourceInterface : public base::RefCountedThreadSafe<ResourceInterface> {
 public:
  // Needs to be called before attempting to allocate specified size.
  // Returns true if requested amount can be allocated.
  // After that the caller can actually allocate it or must call
  // |Discard| if decided not to allocate.
  virtual bool Reserve(uint64_t size) = 0;

  // Reverts reservation.
  // Must be called after the specified amount is released.
  virtual void Discard(uint64_t size) = 0;

  // Returns total amount.
  virtual uint64_t GetTotal() const = 0;