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fix(baseN): encode, decode now return uint8_t zero offset

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SEK1RO
2024-09-19 08:41:59 +03:00
parent f49c0463d4
commit 0086092bd9
2 changed files with 51 additions and 47 deletions
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4
include/base/baseN.hpp
View File

@ -13,9 +13,9 @@ namespace baseN
uint64_t sizeEncoded(std::span<const uint8_t> data, uint8_t base);
uint64_t sizeDecoded(std::string_view str, uint8_t base, const char* digits) noexcept;
void encode(const uint8_t *data, uint64_t data_size, char *str, uint64_t str_size, uint8_t base, const char *digits);
uint64_t encode(const uint8_t *data, uint64_t data_size, char *str, uint64_t str_size, uint8_t base, const char *digits);
std::string encode(std::span<const uint8_t> data, uint8_t base, const char *digits) noexcept;
void decode(const char *str, uint64_t str_size, uint8_t *data, uint64_t data_size, uint8_t base, const char *digits, const int8_t *map);
uint64_t decode(const char *str, uint64_t str_size, uint8_t *data, uint64_t data_size, uint8_t base, const char *digits, const int8_t *map);
std::vector<uint8_t> decode(std::string_view str, uint8_t base, const char *digits, const int8_t *map) noexcept;
}

94
src/baseN.cpp
View File

@ -36,68 +36,62 @@ namespace baseN
str.end());
return sv.size() * std::log(base) / log256 + 1 + (str.size() - sv.size());
}
void encode(const uint8_t *data, uint64_t data_size, char *str, uint64_t str_size, uint8_t base, const char *digits)
uint64_t encode(const uint8_t *data, uint64_t data_size, char *str, uint64_t str_size, uint8_t base, const char *digits)
{
std::vector<uint8_t> dv(std::find_if(data, data + data_size, [](uint8_t item)
{ return item != 0; }),
data + data_size);
if (dv.size() == 0)
{
return;
}
std::span<char> sv(str, str_size);
auto sv_it = sv.rbegin();
auto dv_it = dv.begin();
auto quo_it = dv.begin();
auto quo_it_last = dv.end();
uint16_t div = *dv_it++;
while ((dv[0] > base || quo_it_last > dv.begin() + 1) && sv_it < sv.rend() - 1)
if (dv.size() != 0)
{
if (div < base)
uint16_t div = *dv_it++;
while ((dv[0] > base || quo_it_last > dv.begin() + 1) && sv_it < sv.rend() - 1)
{
div <<= 8;
div += *dv_it++;
}
*quo_it++ = div / base;
div %= base;
while (dv_it < quo_it_last)
{
div <<= 8;
div += *dv_it++;
if (div < base)
{
div <<= 8;
div += *dv_it++;
}
*quo_it++ = div / base;
div %= base;
while (dv_it < quo_it_last)
{
div <<= 8;
div += *dv_it++;
*quo_it++ = div / base;
div %= base;
}
quo_it_last = quo_it;
dv_it = dv.begin();
quo_it = dv.begin();
*sv_it++ = digits[div];
div = *dv_it++;
}
quo_it_last = quo_it;
dv_it = dv.begin();
quo_it = dv.begin();
*sv_it++ = digits[div];
div = *dv_it++;
}
*sv_it++ = digits[div];
for (uint64_t i = 0; i < data_size - dv.size() && sv_it < sv.rend(); i++)
{
*sv_it++ = digits[0];
}
return std::distance(sv_it, sv.rend());
}
std::string encode(std::span<const uint8_t> data, uint8_t base, const char *digits) noexcept
{
std::string str(baseN::sizeEncoded(data, base), ' ');
baseN::encode(data.data(), data.size(), str.data(), str.size(), base, digits);
str.erase(str.begin(), std::find_if(
str.begin(), str.end(), [](char ch)
{ return ch != ' '; }));
uint64_t offset = baseN::encode(data.data(), data.size(), str.data(), str.size(), base, digits);
str.erase(str.begin(), str.begin() + offset);
return str;
}
void decode(const char *str, uint64_t str_size, uint8_t *data, uint64_t data_size, uint8_t base, const char *digits, const int8_t *map)
uint64_t decode(const char *str, uint64_t str_size, uint8_t *data, uint64_t data_size, uint8_t base, const char *digits, const int8_t *map)
{
std::string_view sv(std::find_if(str, str + str_size, [digits](char ch)
{ return ch != digits[0]; }),
str_size);
if (sv.size() == 0)
{
return;
}
str + str_size);
if (!baseN::isValid(sv, map))
{
throw std::logic_error("baseN::decode: out of digits map");
@ -108,27 +102,37 @@ namespace baseN
auto quo_it_last = dv.rbegin() + 1;
uint16_t div;
*quo_it = map[(int8_t)*sv_it++];
while (sv_it < sv.end())
if (sv.size() != 0)
{
div = map[(int8_t)*sv_it++];
while (quo_it < quo_it_last && quo_it < dv.rend() - 1)
*quo_it = map[(int8_t)*sv_it++];
while (sv_it < sv.end())
{
div += *quo_it * base;
*quo_it++ = div;
div >>= 8;
div = map[(int8_t)*sv_it++];
while (quo_it < quo_it_last && quo_it < dv.rend() - 1)
{
div += *quo_it * base;
*quo_it++ = div;
div >>= 8;
}
if (div != 0)
{
*quo_it++ = div;
}
quo_it_last = quo_it;
quo_it = dv.rbegin();
}
*quo_it++ = div;
quo_it_last = quo_it;
quo_it = dv.rbegin();
}
for (uint64_t i = 0; i < str_size - sv.size() && quo_it_last < dv.rend(); i++)
{
*quo_it_last++ = 0;
}
return std::distance(quo_it_last, dv.rend());
}
std::vector<uint8_t> decode(std::string_view str, uint8_t base, const char *digits, const int8_t *map) noexcept
{
std::vector<uint8_t> data(baseN::sizeDecoded(str, base, digits));
baseN::decode(str.data(), str.size(), data.data(), data.size(), base, digits, map);
data.erase(data.begin(), std::find_if(data.begin(), data.end(), [](uint8_t item)
{ return item != 0; }));
uint64_t offset = baseN::decode(str.data(), str.size(), data.data(), data.size(), base, digits, map);
data.erase(data.begin(), data.begin() + offset);
return data;
}
}