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#ifdef NALL_STRING_INTERNAL_HPP
/*
small string optimization (SSO) allocator
sizeof(string) == 16 (amd64)
utilizes a union to store small strings directly into text pointer
bypasses the need to allocate heap memory for small strings
requires extra computations, which can be slower for large strings
pros:
* potential for in-place resize
* no heap allocation when (capacity < 8)
cons:
* added overhead to fetch data()
* 32-bit platforms limited to (capacity < 4)
* pass-by-value requires heap allocation
*/
namespace nall {
char* string::data() {
if(_capacity < SSO) return _text;
return _data;
}
const char* string::data() const {
if(_capacity < SSO) return _text;
return _data;
}
void string::reserve(unsigned capacity) {
if(capacity > _capacity) {
if(capacity >= SSO) {
capacity = bit::round(capacity + 1) - 1;
if(_capacity < SSO) {
char temp[SSO];
memcpy(temp, _text, SSO);
_data = (char*)malloc(capacity + 1);
memcpy(_data, temp, SSO);
} else {
_data = (char*)realloc(_data, capacity + 1);
}
}
_capacity = capacity;
data()[_capacity] = 0;
}
}
void string::resize(unsigned size) {
reserve(size);
data()[_size = size] = 0;
}
void string::reset() {
if(_capacity >= SSO) free(_data);
_data = nullptr;
_capacity = SSO - 1;
_size = 0;
}
string& string::operator=(const string& source) {
if(&source == this) return *this;
reset();
if(source._capacity >= SSO) {
_data = (char*)malloc(source._capacity + 1);
_capacity = source._capacity;
_size = source._size;
memcpy(_data, source.data(), source.size() + 1);
} else {
memcpy(_text, source._text, SSO);
_capacity = SSO - 1;
_size = strlen(_text);
}
return *this;
}
string& string::operator=(string&& source) {
if(&source == this) return *this;
reset();
memcpy(this, &source, sizeof(string));
source._data = nullptr;
source._capacity = SSO - 1;
source._size = 0;
return *this;
}
template<typename T, typename... Args> string::string(T&& source, Args&&... args) {
construct();
sprint(*this, std::forward<T>(source), std::forward<Args>(args)...);
}
string::string() {
construct();
}
string::~string() {
reset();
}
void string::construct() {
_data = nullptr;
_capacity = SSO - 1;
_size = 0;
}
}
#endif
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