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#include "sdsl/ram_filebuf.hpp"
#include <iostream>
#include <limits>
#ifdef WIN32
#include "iso646.h"
#endif
namespace sdsl
{
ram_filebuf::~ram_filebuf() {}
ram_filebuf::ram_filebuf() {}
ram_filebuf::ram_filebuf(std::vector<char>& ram_file) : m_ram_file(&ram_file)
{
char* begin = m_ram_file->data();
char* end = begin + m_ram_file->size();
setg(begin, begin, end); // set get pointers eback(), eptr(), egptr()
}
std::streambuf*
ram_filebuf::open(const std::string name, std::ios_base::openmode mode)
{
// open ram_file
if ((mode & std::ios_base::in) and !(mode & std::ios_base::trunc)) {
// file must exist, initial position at the start
if (!ram_fs::exists(name)) {
m_ram_file = nullptr;
} else {
m_ram_file = &ram_fs::content(name);
}
} else { // existence of file not required
if (!ram_fs::exists(name)) {
// create empty file, if it does not yet exist
ram_fs::store(name, ram_fs::content_type());// TODO: create method in ram_fs?? or store w 1 arg?
}
m_ram_file = &ram_fs::content(name);
if ((mode & std::ios_base::out) and !(mode & std::ios_base::app)) {
m_ram_file->clear();
}
}
if (m_ram_file and(mode & std::ios_base::trunc)) {
m_ram_file->clear();
}
if (m_ram_file) {
if (mode & std::ios_base::ate) {
// TODO: move put pointer to the end of the file
} else {
}
setg(m_ram_file->data(), m_ram_file->data(), m_ram_file->data()+m_ram_file->size());
setp(m_ram_file->data(), m_ram_file->data()+m_ram_file->size());
}
// ATTENTION: if m_ram_file->size() == 0, then data might be nullptr !!!
return m_ram_file ? this : nullptr;
}
bool
ram_filebuf::is_open()
{
return m_ram_file!=nullptr;
}
ram_filebuf*
ram_filebuf::close()
{
if (!this->is_open())
return nullptr;
m_ram_file = nullptr;
setg(nullptr, nullptr, nullptr);
setp(nullptr, nullptr);
return this;
}
ram_filebuf::pos_type
ram_filebuf::seekpos(pos_type sp, std::ios_base::openmode mode)
{
if (sp >= (pos_type)0 and sp <= (pos_type)m_ram_file->size()) {
setg(m_ram_file->data(), m_ram_file->data()+sp, m_ram_file->data()+m_ram_file->size());
setp(m_ram_file->data(), m_ram_file->data()+m_ram_file->size());
pbump64(sp);
} else {
if (mode & std::ios_base::out) {
// extend buffer
m_ram_file->resize(sp, 0);
setg(m_ram_file->data(), m_ram_file->data()+sp, m_ram_file->data()+m_ram_file->size());
setp(m_ram_file->data(), m_ram_file->data()+m_ram_file->size());
pbump64(sp);
} else {
return pos_type(off_type(-1));
}
}
return sp;
}
ram_filebuf::pos_type
ram_filebuf::pubseekoff(off_type off, std::ios_base::seekdir way,
std::ios_base::openmode which)
{
if (std::ios_base::beg == way) {
if (seekpos(off, which) == pos_type(-1)) {
return pos_type(-1);
}
} else if (std::ios_base::cur == way) {
if (seekpos(gptr()-eback()+off, which) == pos_type(-1)) {
return pos_type(-1);
}
} else if (std::ios_base::end == way) {
if (seekpos(egptr()-eback()+off, which) == pos_type(-1)) {
return pos_type(-1);
}
}
return gptr()-eback();
}
ram_filebuf::pos_type
ram_filebuf::pubseekpos(pos_type sp, std::ios_base::openmode which)
{
if (seekpos(sp, which) == pos_type(-1)) {
return pos_type(-1);
} else {
return gptr()-eback();
}
}
int
ram_filebuf::sync()
{
return 0; // we are always in sync, since buffer is sink
}
ram_filebuf::int_type
ram_filebuf::overflow(int_type c)
{
if (m_ram_file) {
m_ram_file->push_back(c);
setp(m_ram_file->data(), m_ram_file->data()+m_ram_file->size());
std::ptrdiff_t add = epptr()-pbase();
pbump64(add);
setg(m_ram_file->data(), gptr(), m_ram_file->data()+m_ram_file->size());
}
return traits_type::to_int_type(c);
}
void ram_filebuf::pbump64(std::ptrdiff_t x)
{
while (x > std::numeric_limits<int>::max()) {
pbump(std::numeric_limits<int>::max());
x -= std::numeric_limits<int>::max();
}
pbump(x);
}
}
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