50 lines
1.8 KiB
C++
50 lines
1.8 KiB
C++
// See resample_name.h.
|
|
|
|
#include "core/model/resample_name.h"
|
|
|
|
#include <cctype>
|
|
|
|
namespace reasampler::model {
|
|
|
|
namespace {
|
|
|
|
constexpr const char* kFallbackStem = "resample";
|
|
constexpr int kFirstIteration = 2; // the source itself is iteration 1
|
|
|
|
// The " r<digits>" tail, if the name ends in one and the digits are a whole number > 0.
|
|
// Returns 0 (no tail) otherwise; `stemLength` is then left untouched.
|
|
int trailingIteration(const std::string& name, std::size_t& stemLength) {
|
|
std::size_t digitsBegin = name.size();
|
|
while (digitsBegin > 0 && std::isdigit(static_cast<unsigned char>(name[digitsBegin - 1])))
|
|
--digitsBegin;
|
|
if (digitsBegin == name.size()) return 0; // no digits at the end
|
|
if (digitsBegin < 2) return 0; // no room for " r"
|
|
if (name[digitsBegin - 1] != 'r' || name[digitsBegin - 2] != ' ') return 0;
|
|
|
|
// Overflow-safe accumulate: a pathological digit run stops counting rather than
|
|
// wrapping into a small number and silently reusing an existing name.
|
|
int value = 0;
|
|
for (std::size_t i = digitsBegin; i < name.size(); ++i) {
|
|
if (value > 1000000) return 0;
|
|
value = value * 10 + (name[i] - '0');
|
|
}
|
|
if (value <= 0) return 0;
|
|
stemLength = digitsBegin - 2;
|
|
return value;
|
|
}
|
|
|
|
} // namespace
|
|
|
|
std::string nextIterationName(const std::string& sourceName) {
|
|
if (sourceName.empty())
|
|
return std::string(kFallbackStem) + " r" + std::to_string(kFirstIteration);
|
|
|
|
std::size_t stemLength = sourceName.size();
|
|
const int current = trailingIteration(sourceName, stemLength);
|
|
if (current > 0)
|
|
return sourceName.substr(0, stemLength) + " r" + std::to_string(current + 1);
|
|
return sourceName + " r" + std::to_string(kFirstIteration);
|
|
}
|
|
|
|
} // namespace reasampler::model
|