Luna/luna/src/Units.cpp

#include <luna/Alloc.h>
#include <luna/Format.h>
#include <luna/Result.h>
#include <luna/ScopeGuard.h>
#include <luna/Units.h>

Result<usize> to_dynamic_unit_cstr(usize value, char* buffer, usize max)
{
    if (value < 1024) { return string_format(buffer, max, "%u bytes", value); }

    const char* unit_prefixes = "KMGTPE";
    while (value > (1024 * 1024))
    {
        value /= 1024;
        unit_prefixes++;
    }

    return string_format(buffer, max, "%u.%u %ciB", value / 1024, (value % 1024) / 103, *unit_prefixes);
}

Result<OwnedStringView> to_dynamic_unit(usize value)
{
    char* buf = TRY(make_array<char>(64));

    auto guard = make_scope_guard([&] { destroy_array(buf); });

    TRY(to_dynamic_unit_cstr(value, buf, 64));

    guard.deactivate();

    return OwnedStringView{buf};
}