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#include "cpp11/R.hpp"
#include "cpp11/function.hpp"
#include "cpp11/raws.hpp"
#include "cpp11/strings.hpp"
#include <fstream>
// Wrapper around R's read_bin function
SEXP read_bin(const cpp11::sexp& con, int bytes) {
static auto readBin = cpp11::package("base")["readBin"];
return readBin(con, "raw", bytes);
}
// Read data from a connection in chunks and then combine into a single
// raw vector.
//
[[cpp11::register]] std::string
read_connection_(const cpp11::sexp& con, std::string filename, int chunk_size) {
std::ofstream out(filename.c_str(), std::fstream::out | std::fstream::binary);
SEXP chunk = read_bin(con, chunk_size);
R_xlen_t chunk_len = Rf_xlength(chunk);
while (chunk_len > 0) {
std::copy(
RAW(chunk),
RAW(chunk) + Rf_xlength(chunk),
std::ostream_iterator<char>(out));
chunk = read_bin(con, chunk_size);
chunk_len = Rf_xlength(chunk);
}
return filename;
}
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