ZipFileAdapter.cc

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#include "ZipFileAdapter.hh"
#include "ZlibInflate.hh"
#include "FileException.hh"
 
namespace openmsx {
 
ZipFileAdapter::ZipFileAdapter(std::unique_ptr<FileBase> file_)
        : CompressedFileAdapter(std::move(file_))
{
}
 
void ZipFileAdapter::decompress(FileBase& f, Decompressed& d)
{
        ZlibInflate zlib(f.mmap());
 
        if (zlib.get32LE() != 0x04034B50) {
                throw FileException("Invalid ZIP file");
        }
 
        // skip "version needed to extract" and "general purpose bit flag"
        zlib.skip(2 + 2);
 
        // compression method
        if (zlib.get16LE() != 0x0008) {
                throw FileException("Unsupported zip compression method");
        }
 
        // skip "last mod file time", "last mod file data",
        //      "crc32",              "compressed size"
        zlib.skip(2 + 2 + 4 + 4);
 
        unsigned origSize = zlib.get32LE(); // uncompressed size
        unsigned filenameLen = zlib.get16LE(); // filename length
        unsigned extraFieldLen = zlib.get16LE(); // extra field length
        d.originalName = zlib.getString(filenameLen); // original filename
        zlib.skip(extraFieldLen); // skip "extra field"
 
        d.buf = zlib.inflate(origSize);
}
 
} // namespace openmsx