/// <summary>
/// Read the version information that specifies the minimum versions of the
/// DataSpaceManager software that can read, write, or update the data space
/// information in this file.
/// </summary>
/// <param name="dataSpaceStorage"></param>
/// <exception cref="FileFormatException">
/// If the format version information in the stream is corrupt.
/// </exception>
private void ReadDataSpaceVersionInformation(StorageInfo dataSpaceStorage)
{
if (_fileFormatVersion == null)
{
if (dataSpaceStorage.StreamExists( DataSpaceVersionName ))
{
StreamInfo versionStreamInfo = dataSpaceStorage.GetStreamInfo( DataSpaceVersionName );
using (Stream versionStream = versionStreamInfo.GetStream(FileMode.Open))
{
_fileFormatVersion = FormatVersion.LoadFromStream(versionStream);
// Transform Identifier: we preserve casing, but do case-insensitive comparison
//Case-insensitive comparison. As per recommendations, we convert both strings
//to Upper case and then compare with StringComparison.Ordinal
if (!((IEqualityComparer) CU.StringCaseInsensitiveComparer).Equals(_fileFormatVersion.FeatureIdentifier,
DataSpaceVersionIdentifier))
{
throw new FileFormatException(
SR.Get(SRID.InvalidTransformFeatureName,
_fileFormatVersion.FeatureIdentifier,
DataSpaceVersionIdentifier));
}
// If we ever write this version number out again, we will want to record
// the fact that it was done by the current version of the Dataspace software.
_fileFormatVersion.WriterVersion = DataSpaceCurrentWriterVersion;
}
}
}
}
/// <summary>
/// Write the data space mapping table to underlying storage.
/// </summary>
void WriteDataSpaceMap()
{
ThrowIfIncorrectUpdaterVersion();
StorageInfo dataSpaceStorage =
new StorageInfo( _associatedStorage, DataSpaceStorageName );
StreamInfo dataSpaceMapStreamInfo =
new StreamInfo ( dataSpaceStorage, DataSpaceMapTableName );
if( 0 < _dataSpaceMap.Count )
{
// Write versioning information
StreamInfo versionStreamInfo = null;
if (dataSpaceStorage.StreamExists( DataSpaceVersionName ) )
versionStreamInfo = dataSpaceStorage.GetStreamInfo( DataSpaceVersionName );
else
versionStreamInfo = dataSpaceStorage.CreateStream( DataSpaceVersionName );
Stream versionStream = versionStreamInfo.GetStream();
_fileFormatVersion.SaveToStream(versionStream);
versionStream.Close();
// Create stream for write, overwrite any existing
using(Stream dataSpaceMapStream = dataSpaceMapStreamInfo.GetStream(FileMode.Create))
{
using(BinaryWriter dataSpaceMapWriter =
new BinaryWriter( dataSpaceMapStream, System.Text.Encoding.Unicode ))
{
// Write header
// header length = our known size + preserved array size
dataSpaceMapWriter.Write(
checked ((Int32) (KnownBytesInMapTableHeader + _mapTableHeaderPreservation.Length)));
// number of entries
dataSpaceMapWriter.Write(
_dataSpaceMap.Count );
// anything else we've preserved
dataSpaceMapWriter.Write(
_mapTableHeaderPreservation );
// Loop to write entries
foreach( CompoundFileReference o in _dataSpaceMap.Keys )
{
// determine the entry length
string label = (string)_dataSpaceMap[o];
int entryLength = CompoundFileReference.Save(o, null);
checked { entryLength += CU.WriteByteLengthPrefixedDWordPaddedUnicodeString(null, label); }
// length of entryLength itself
checked { entryLength += 4; }
// write out the entry length
dataSpaceMapWriter.Write((Int32) entryLength);
// Write out reference
CompoundFileReference.Save( o, dataSpaceMapWriter);
// Write out dataspace label
CU.WriteByteLengthPrefixedDWordPaddedUnicodeString(
dataSpaceMapWriter, label);
}
}
}
}
else
{
// data space map is empty, remove existing stream if there.
if ( dataSpaceStorage.StreamExists( DataSpaceMapTableName ) )
dataSpaceStorage.DeleteStream( DataSpaceMapTableName );
}
}