63 lines
2.4 KiB
C
63 lines
2.4 KiB
C
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// Copyright 2021 The Abseil Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// https://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#ifndef ABSL_STRINGS_CORD_ANALYSIS_H_
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#define ABSL_STRINGS_CORD_ANALYSIS_H_
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#include <cstddef>
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#include <cstdint>
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#include "absl/base/config.h"
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#include "absl/strings/internal/cord_internal.h"
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namespace absl {
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ABSL_NAMESPACE_BEGIN
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namespace cord_internal {
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// Returns the *approximate* number of bytes held in full or in part by this
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// Cord (which may not remain the same between invocations). Cords that share
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// memory could each be "charged" independently for the same shared memory.
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size_t GetEstimatedMemoryUsage(const CordRep* rep);
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// Returns the *approximate* number of bytes held in full or in part by this
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// Cord for the distinct memory held by this cord. This is similar to
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// `GetEstimatedMemoryUsage()`, except that if the cord has multiple references
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// to the same memory, that memory is only counted once.
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//
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// For example:
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// absl::Cord cord;
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// cord.append(some_other_cord);
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// cord.append(some_other_cord);
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// // Calls GetEstimatedMemoryUsage() and counts `other_cord` twice:
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// cord.EstimatedMemoryUsage(kTotal);
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// // Calls GetMorePreciseMemoryUsage() and counts `other_cord` once:
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// cord.EstimatedMemoryUsage(kTotalMorePrecise);
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//
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// This is more expensive than `GetEstimatedMemoryUsage()` as it requires
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// deduplicating all memory references.
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size_t GetMorePreciseMemoryUsage(const CordRep* rep);
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// Returns the *approximate* number of bytes held in full or in part by this
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// CordRep weighted by the sharing ratio of that data. For example, if some data
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// edge is shared by 4 different Cords, then each cord is attribute 1/4th of
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// the total memory usage as a 'fair share' of the total memory usage.
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size_t GetEstimatedFairShareMemoryUsage(const CordRep* rep);
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} // namespace cord_internal
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ABSL_NAMESPACE_END
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} // namespace absl
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#endif // ABSL_STRINGS_CORD_ANALYSIS_H_
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