supercell-wx/wxdata/source/scwx/wsr88d/nexrad_file_factory.cpp
2022-02-10 22:10:22 -06:00

125 lines
2.9 KiB
C++

#include <scwx/wsr88d/nexrad_file_factory.hpp>
#include <scwx/wsr88d/ar2v_file.hpp>
#include <scwx/wsr88d/level3_file.hpp>
#include <fstream>
#include <sstream>
#include <boost/iostreams/copy.hpp>
#include <boost/iostreams/filtering_streambuf.hpp>
#include <boost/iostreams/filter/gzip.hpp>
#include <boost/log/trivial.hpp>
namespace scwx
{
namespace wsr88d
{
static const std::string logPrefix_ = "[scwx::wsr88d::nexrad_file_factory] ";
std::shared_ptr<NexradFile>
NexradFileFactory::Create(const std::string& filename)
{
BOOST_LOG_TRIVIAL(debug) << logPrefix_ << "Create(" << filename << ")";
std::shared_ptr<NexradFile> nexradFile = nullptr;
bool fileValid = true;
std::ifstream f(filename, std::ios_base::in | std::ios_base::binary);
if (!f.good())
{
BOOST_LOG_TRIVIAL(warning)
<< logPrefix_ << "Could not open file for reading: " << filename;
fileValid = false;
}
if (fileValid)
{
nexradFile = Create(f);
}
return nexradFile;
}
std::shared_ptr<NexradFile> NexradFileFactory::Create(std::istream& is)
{
std::shared_ptr<NexradFile> message = nullptr;
std::istream* pis = &is;
std::streampos pisBegin = is.tellg();
std::stringstream ss;
std::string buffer;
bool dataValid;
buffer.resize(4);
is.read(buffer.data(), 4);
dataValid = is.good();
is.seekg(pisBegin, std::ios_base::beg);
if (dataValid && buffer.starts_with("\x1f\x8b"))
{
boost::iostreams::filtering_streambuf<boost::iostreams::input> in;
in.push(boost::iostreams::gzip_decompressor());
in.push(is);
try
{
std::streamsize bytesCopied = boost::iostreams::copy(in, ss);
pis = &ss;
pisBegin = ss.tellg();
ss.read(buffer.data(), 4);
dataValid = ss.good();
ss.seekg(pisBegin, std::ios_base::beg);
BOOST_LOG_TRIVIAL(trace)
<< logPrefix_ << "Decompressed file = " << bytesCopied << " bytes";
if (!dataValid)
{
BOOST_LOG_TRIVIAL(warning)
<< logPrefix_ << "Error reading decompressed stream";
}
}
catch (const boost::iostreams::gzip_error& ex)
{
BOOST_LOG_TRIVIAL(warning)
<< logPrefix_ << "Error decompressing file: " << ex.what();
dataValid = false;
}
}
else if (!dataValid)
{
BOOST_LOG_TRIVIAL(warning) << logPrefix_ << "Error reading file";
}
if (dataValid)
{
if (buffer.starts_with("AR2V"))
{
message = std::make_shared<Ar2vFile>();
}
else
{
message = std::make_shared<Level3File>();
}
}
if (message != nullptr)
{
dataValid = message->LoadData(*pis);
if (!dataValid)
{
message = nullptr;
}
}
return message;
}
} // namespace wsr88d
} // namespace scwx