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// Copyright 2021 The Abseil Authors

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//     https://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

#ifndef ABSL_STRINGS_CORD_ANALYSIS_H_

#define ABSL_STRINGS_CORD_ANALYSIS_H_

#include <cstddef>

#include <cstdint>

#include "absl/base/config.h"

#include "absl/strings/internal/cord_internal.h"

namespace absl {

ABSL_NAMESPACE_BEGIN

namespace cord_internal {

// Returns the *approximate* number of bytes held in full or in part by this

// Cord (which may not remain the same between invocations). Cords that share

// memory could each be "charged" independently for the same shared memory.

size_t GetEstimatedMemoryUsage(const CordRep* rep);

// Returns the *approximate* number of bytes held in full or in part by this

// Cord for the distinct memory held by this cord. This is similar to

// `GetEstimatedMemoryUsage()`, except that if the cord has multiple references

// to the same memory, that memory is only counted once.

//

// For example:

//   absl::Cord cord;

//   cord.append(some_other_cord);

//   cord.append(some_other_cord);

//    // Calls GetEstimatedMemoryUsage() and counts `other_cord` twice:

//   cord.EstimatedMemoryUsage(kTotal);

//    // Calls GetMorePreciseMemoryUsage() and counts `other_cord` once:

//   cord.EstimatedMemoryUsage(kTotalMorePrecise);

//

// This is more expensive than `GetEstimatedMemoryUsage()` as it requires

// deduplicating all memory references.

size_t GetMorePreciseMemoryUsage(const CordRep* rep);

// Returns the *approximate* number of bytes held in full or in part by this

// CordRep weighted by the sharing ratio of that data. For example, if some data

// edge is shared by 4 different Cords, then each cord is attribute 1/4th of

// the total memory usage as a 'fair share' of the total memory usage.

size_t GetEstimatedFairShareMemoryUsage(const CordRep* rep);

}  // namespace cord_internal

ABSL_NAMESPACE_END

}  // namespace absl

#endif  // ABSL_STRINGS_CORD_ANALYSIS_H_