private static void WriteTiltZipHeader(Stream s, TiltZipHeader header)
{
unsafe {
// This doesn't work because we need a byte[] to pass to Stream
// byte* bufp = stackalloc byte[sizeof(TiltZipHeader)];
// This doesn't work because the type is also byte*, not byte[]
// unsafe struct Foo { fixed byte buf[N]; }
Debug.Assert(
HEADER_SIZE == Marshal.SizeOf(header),
"Reference types detected in TiltZipHeader");
byte[] buf = new byte[HEADER_SIZE];
fixed(byte *bufp = buf)
{
IntPtr bufip = (IntPtr)bufp;
// Copy from undefined CLR layout to explicitly-defined layout
Marshal.StructureToPtr(header, bufip, false);
s.Write(buf, 0, buf.Length);
// Need this if there are reference types, but in that case
// there are other complications (like demarshaling)
// Marshal.DestroyStructure(bufip, typeof(TiltZipHeader));
}
}
}
public AtomicWriter(string path)
{
m_destination = path;
m_temporaryPath = path + "_part";
Destroy(m_temporaryPath);
bool useZip;
switch (DevOptions.I.PreferredTiltFormat)
{
case TiltFormat.Directory:
useZip = false;
break;
case TiltFormat.Inherit:
useZip = !Directory.Exists(path);
break;
default:
case TiltFormat.Zip:
useZip = true;
break;
}
if (useZip)
{
Directory.CreateDirectory(Path.GetDirectoryName(m_temporaryPath));
FileStream tmpfs = new FileStream(m_temporaryPath, FileMode.Create, FileAccess.Write);
var header = new TiltZipHeader
{
sentinel = TILT_SENTINEL,
headerSize = HEADER_SIZE,
headerVersion = HEADER_VERSION,
};
WriteTiltZipHeader(tmpfs, header);
m_zipstream = new ZipLibrary.ZipOutputStream(tmpfs);
#if USE_DOTNETZIP
// Ionic.Zip documentation says that using compression level None produces
// zip files that cannot be opened with the default OSX zip reader.
// But compression _method_ none seems fine?
m_zipstream.CompressionMethod = ZipLibrary.CompressionMethod.None;
m_zipstream.EnableZip64 = ZipLibrary.Zip64Option.Never;
#else
m_zipstream.SetLevel(0); // no compression
// Since we don't have size info up front, it conservatively assumes 64-bit.
// We turn it off to maximize compatibility with wider ecosystem (eg, osx unzip).
m_zipstream.UseZip64 = ZipLibrary.UseZip64.Off;
#endif
}
else
{
Directory.CreateDirectory(m_temporaryPath);
}
}
