xo-alloc/include/xo/unit/basis_unit2.hpp

345 lines
15 KiB
C++

/** @file basis_unit2.hpp **/
#pragma once
#include "dim_util2.hpp"
#include "xo/ratio/ratio.hpp"
#include <algorithm>
#include <vector>
namespace xo {
namespace unit {
using basis_unit2_abbrev_type = flatstring<16>;
using scalefactor_ratio_type = xo::ratio::ratio<std::int64_t>;
/** @class basis_unit2
* @brief A dimensionless multiple of a single natively-specified basis dimension
*
* For example "3600 minutes" or "1e-6 grams"
**/
struct basis_unit2 {
public:
constexpr basis_unit2(dim native_dim, const scalefactor_ratio_type & scalefactor)
: native_dim_{native_dim},
scalefactor_{scalefactor}
{}
constexpr dim native_dim() const { return native_dim_; }
constexpr const scalefactor_ratio_type & scalefactor() const { return scalefactor_; }
/** @brief identifies a native unit, e.g. time (in seconds) **/
const dim native_dim_;
/** @brief this unit defined as multiple scalefactor times native unit **/
const scalefactor_ratio_type scalefactor_;
};
namespace units {
/** for runtime work, would like to be able to promptly find special abbreviation
* keyed by (native_dim, scalefactor).
*
* Also want to support compile-time-only unit computation.
* Since constexpr unordered containers aren't obviously feasible (as of c++23).
*
* Solution adopted here is to support introduction of scaled native units
* only at compile time, at least for now
**/
// ----- scaled_native_unit_abbrev_helper -----
/* Require: InnerScale is ratio type; InnerScale >= 1
*
* NOTE: clang 18 doesn't accept that scalefactor_ratio_type is a 'structural type'
*/
template <dim BasisDim, std::int64_t InnerScaleNum = 1, std::int64_t InnerScaleDen = 1>
struct scaled_native_unit2_abbrev;
template <dim BasisDim>
struct scaled_native_unit2_abbrev<BasisDim, 1, 1> {
static constexpr const basis_unit2_abbrev_type value
= (basis_unit2_abbrev_type::from_flatstring
(native_unit2_v[static_cast<uint32_t>(BasisDim)]
.abbrev_str()));
};
inline
constexpr basis_unit2_abbrev_type
bu_fallback_abbrev(dim basis_dim,
const scalefactor_ratio_type & scalefactor)
{
return (basis_unit2_abbrev_type::from_flatstring
(flatstring_concat
(scalefactor.to_str<basis_unit2_abbrev_type::fixed_capacity>(),
native_unit2_v[static_cast<std::uint32_t>(basis_dim)].abbrev_str())));
}
template <dim BasisDim,
std::int64_t InnerScaleNum,
std::int64_t InnerScaleDen>
struct scaled_native_unit2_abbrev {
/* e.g. unit of '1000 grams' will have abbrev '1000g' in absence
* of a specialization for scaled_native_unit_abbrev
*/
static constexpr const basis_unit2_abbrev_type value
= (basis_unit2_abbrev_type::from_flatstring
(flatstring_concat
(xo::ratio::ratio<std::int64_t>(InnerScaleNum,
InnerScaleDen)
.to_str<basis_unit2_abbrev_type::fixed_capacity>(),
native_unit2_v[static_cast<std::uint32_t>(BasisDim)].abbrev_str())));
// = bu_fallback_abbrev(BasisDim,
// xo::ratio::ratio<std::int64_t>(InnerScaleNum, InnerScaleDen));
};
// ----- units for dim::mass -----
template <>
struct scaled_native_unit2_abbrev<dim::mass, 1, 1000000000> {
static constexpr const basis_unit2_abbrev_type value = basis_unit2_abbrev_type::from_chars("ng");
};
template <>
struct scaled_native_unit2_abbrev<dim::mass, 1, 1000000> {
static constexpr const basis_unit2_abbrev_type value = basis_unit2_abbrev_type::from_chars("ug");
};
template <>
struct scaled_native_unit2_abbrev<dim::mass, 1, 1000> {
static constexpr const basis_unit2_abbrev_type value = basis_unit2_abbrev_type::from_chars("mg");
};
template <>
struct scaled_native_unit2_abbrev<dim::mass, 1000, 1> {
static constexpr const basis_unit2_abbrev_type value = basis_unit2_abbrev_type::from_chars("kg");
};
template <>
struct scaled_native_unit2_abbrev<dim::mass, 1000000, 1> {
static constexpr const basis_unit2_abbrev_type value = basis_unit2_abbrev_type::from_chars("t");
};
template <>
struct scaled_native_unit2_abbrev<dim::mass, 1000000000, 1> {
static constexpr const basis_unit2_abbrev_type value = basis_unit2_abbrev_type::from_chars("kt");
};
// ----- units for dim::distance -----
template <>
struct scaled_native_unit2_abbrev<dim::distance, 1, 1000000000> {
static constexpr const basis_unit2_abbrev_type value = basis_unit2_abbrev_type::from_chars("nm");
};
template <>
struct scaled_native_unit2_abbrev<dim::distance, 1, 1000000> {
static constexpr const basis_unit2_abbrev_type value = basis_unit2_abbrev_type::from_chars("um");
};
template <>
struct scaled_native_unit2_abbrev<dim::distance, 1, 1000> {
static constexpr const basis_unit2_abbrev_type value = basis_unit2_abbrev_type::from_chars("mm");
};
template <>
struct scaled_native_unit2_abbrev<dim::distance, 1000, 1> {
static constexpr const basis_unit2_abbrev_type value = basis_unit2_abbrev_type::from_chars("km");
};
// ----- units for dim::time -----
template <>
struct scaled_native_unit2_abbrev<dim::time, 1, 1000000000> {
static constexpr const basis_unit2_abbrev_type value = basis_unit2_abbrev_type::from_chars("ns");
};
template <>
struct scaled_native_unit2_abbrev<dim::time, 1, 1000000> {
static constexpr const basis_unit2_abbrev_type value = basis_unit2_abbrev_type::from_chars("us");
};
template <>
struct scaled_native_unit2_abbrev<dim::time, 1, 1000> {
static constexpr const basis_unit2_abbrev_type value = basis_unit2_abbrev_type::from_chars("ms");
};
template <>
struct scaled_native_unit2_abbrev<dim::time, 60, 1> {
static constexpr const basis_unit2_abbrev_type value = basis_unit2_abbrev_type::from_chars("min");
};
template <>
struct scaled_native_unit2_abbrev<dim::time, 3600, 1> {
static constexpr const basis_unit2_abbrev_type value = basis_unit2_abbrev_type::from_chars("hr");
};
template <>
struct scaled_native_unit2_abbrev<dim::time, 24*3600, 1> {
static constexpr const basis_unit2_abbrev_type value = basis_unit2_abbrev_type::from_chars("dy");
};
template <>
struct scaled_native_unit2_abbrev<dim::time, 250*24*3600, 1> {
static constexpr const basis_unit2_abbrev_type value = basis_unit2_abbrev_type::from_chars("yr250");
};
template <>
struct scaled_native_unit2_abbrev<dim::time, 360*24*3600, 1> {
static constexpr const basis_unit2_abbrev_type value = basis_unit2_abbrev_type::from_chars("yr360");
};
template <>
struct scaled_native_unit2_abbrev<dim::time, 365*24*3600, 1> {
static constexpr const basis_unit2_abbrev_type value = basis_unit2_abbrev_type::from_chars("yr365");
};
// ----- native unit abbrev api -----
template <dim BasisDim, std::int64_t InnerScaleNum = 1, std::int64_t InnerScaleDen = 1>
constexpr auto scaled_native_unit2_abbrev_v = scaled_native_unit2_abbrev<BasisDim, InnerScaleNum, InnerScaleDen>::value;
}
/** @class basis_unit2_store
* @brief Store known basis units for runtime
**/
template <typename Tag>
struct basis_unit2_store {
basis_unit2_store() : bu_abbrev_vv_(static_cast<std::size_t>(dim::n_dim)) {
this->bu_establish_abbrev_for<dim::mass, 1, 1000000000>();
this->bu_establish_abbrev_for<dim::mass, 1, 1000000>();
this->bu_establish_abbrev_for<dim::mass, 1, 1000>();
this->bu_establish_abbrev_for<dim::mass, 1, 1>();
this->bu_establish_abbrev_for<dim::mass, 1000, 1>();
this->bu_establish_abbrev_for<dim::mass, 1000000, 1>();
this->bu_establish_abbrev_for<dim::mass, 1000000000, 1>();
this->bu_establish_abbrev_for<dim::distance, 1, 1000000000>();
this->bu_establish_abbrev_for<dim::distance, 1, 1000000>();
this->bu_establish_abbrev_for<dim::distance, 1, 1000>();
this->bu_establish_abbrev_for<dim::distance, 1, 1>();
this->bu_establish_abbrev_for<dim::distance, 1000, 1>();
this->bu_establish_abbrev_for<dim::time, 1, 1000000000>();
this->bu_establish_abbrev_for<dim::time, 1, 1000000>();
this->bu_establish_abbrev_for<dim::time, 1, 1000>();
this->bu_establish_abbrev_for<dim::time, 1, 1>();
this->bu_establish_abbrev_for<dim::time, 60, 1>();
this->bu_establish_abbrev_for<dim::time, 3600, 1>();
this->bu_establish_abbrev_for<dim::time, 24*3600, 1>();
this->bu_establish_abbrev_for<dim::time, 250*24*3600, 1>();
this->bu_establish_abbrev_for<dim::time, 360*24*3600, 1>();
this->bu_establish_abbrev_for<dim::time, 365*24*3600, 1>();
this->bu_establish_abbrev_for<dim::currency, 1, 1>();
this->bu_establish_abbrev_for<dim::price, 1, 1>();
}
/* e.g.
* [(1/1000000000, "nm"), (1/1000000, "um"), (1/1000, "mm"), (1/1, "m"), (1000/1, "km")]
*/
using native_scale_v = std::vector<std::pair<scalefactor_ratio_type, basis_unit2_abbrev_type>>;
/** @brief get basis-unit abbreviation at runtime **/
basis_unit2_abbrev_type bu_abbrev(dim basis_dim,
const scalefactor_ratio_type & scalefactor) const {
const auto & bu_abbrev_v = bu_abbrev_vv_[static_cast<std::size_t>(basis_dim)];
std::size_t i_abbrev = bu_abbrev_lub_ix(basis_dim, scalefactor, bu_abbrev_v);
if ((i_abbrev < bu_abbrev_v.size())
&& (bu_abbrev_v[i_abbrev].first == scalefactor))
{
return bu_abbrev_v[i_abbrev].second;
} else {
return units::bu_fallback_abbrev(basis_dim, scalefactor);
}
}
template <dim BasisDim, std::int64_t InnerScaleNum, std::int64_t InnerScaleDen>
void bu_establish_abbrev_for() {
this->bu_establish_abbrev(basis_unit2(BasisDim,
scalefactor_ratio_type(InnerScaleNum, InnerScaleDen)),
units::scaled_native_unit2_abbrev_v<BasisDim, InnerScaleNum, InnerScaleDen>);
}
/** @brief establish abbreviation @p abbrev for basis unit @p bu
**/
void bu_establish_abbrev(const basis_unit2 & bu,
const basis_unit2_abbrev_type & abbrev) {
auto & bu_abbrev_v = bu_abbrev_vv_[static_cast<std::size_t>(bu.native_dim())];
std::int32_t i_abbrev = 0;
if (!bu_abbrev_v.empty()) {
i_abbrev = bu_abbrev_lub_ix(bu.native_dim(),
bu.scalefactor(),
bu_abbrev_v);
}
auto entry = std::make_pair(bu.scalefactor(), abbrev);
if ((i_abbrev < bu_abbrev_v.size())
&& (bu_abbrev_v[i_abbrev].first == bu.scalefactor()))
{
bu_abbrev_v[i_abbrev] = entry;
} else {
bu_abbrev_v.insert(bu_abbrev_v.begin() + i_abbrev, entry);
}
}
private:
/** @brief get least-upper-bound index position in bu_abbrev_v[]
*
* return value in [0, n] where n = bu_abbrev_v.size()
**/
static std::size_t bu_abbrev_lub_ix(dim basis_dim,
const scalefactor_ratio_type & scalefactor,
const native_scale_v & bu_abbrev_v)
{
std::size_t n = bu_abbrev_v.size();
if (n == 0)
return 0;
std::size_t lo = 0;
std::size_t hi = n-1;
if (scalefactor <= bu_abbrev_v[lo].first)
return 0;
auto cmp = (scalefactor <=> bu_abbrev_v[hi].first);
if (cmp > 0)
return n;
if (cmp == 0)
return hi;
while (hi-lo > 1) {
/* inv:
* bu_abbrev_v[lo].first < scalefactor <= bu_abbrev_v[hi].first
*/
std::size_t mid = lo + (hi - lo)/2;
if (scalefactor > bu_abbrev_v[mid].first)
lo = mid;
else
hi = mid;
}
return hi;
}
private:
/* bu_abbrev_v[dim] holds known units for native unit dim */
std::vector<native_scale_v> bu_abbrev_vv_;
};
} /*namespace unit*/
} /*namespace xo*/
/** end basis_unit2.hpp **/