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// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
#pragma once
#include <vespa/persistence/spi/bucket_limits.h>
#include <cstdint>
#include <cstdlib>
namespace storage {
constexpr static uint8_t MaxStripeBits = spi::BucketLimits::MinUsedBits;
constexpr static uint32_t MaxStripes = (1ULL << MaxStripeBits);
/**
* Returns the stripe in which the given bucket key belongs,
* when using the given number of stripe bits.
*/
size_t stripe_of_bucket_key(uint64_t key, uint8_t n_stripe_bits) noexcept;
/**
* Returns the number of stripe bits used to represent the given number of stripes.
*
* This also asserts that the number of stripes is valid (power of 2 and within MaxStripes boundary).
*/
uint8_t calc_num_stripe_bits(uint32_t n_stripes) noexcept;
/**
* Validates the number of stripes and returns the (potentially adjusted) value.
*
* This ensures the number of stripes is a power of 2 and within MaxStripes boundary.
*/
[[nodiscard]] uint32_t adjusted_num_stripes(uint32_t n_stripes) noexcept;
/**
* Tune the number of stripes based on the number of CPU cores.
*/
uint32_t tune_num_stripes_based_on_cpu_cores(uint32_t cpu_cores) noexcept;
}
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