private void ReadCentralDirectory()
{
try
{
// assume ReadEndOfCentralDirectory has been called and has populated _centralDirectoryStart
_archiveStream.Seek(_centralDirectoryStart, SeekOrigin.Begin);
long numberOfEntries = 0;
//read the central directory
ZipCentralDirectoryFileHeader currentHeader;
bool saveExtraFieldsAndComments = Mode == ZipArchiveMode.Update;
while (ZipCentralDirectoryFileHeader.TryReadBlock(_archiveReader,
saveExtraFieldsAndComments, out currentHeader))
{
AddEntry(new ReadOnlyZipArchiveEntry(this, currentHeader));
numberOfEntries++;
}
if (numberOfEntries != _expectedNumberOfEntries)
{
throw new InvalidDataException("NumEntriesWrong");
}
}
catch (EndOfStreamException ex)
{
throw new InvalidDataException("CentralDirectoryInvalid", ex);
}
}
// Initializes, attaches it to archive
internal ReadOnlyZipArchiveEntry(ReadOnlyZipArchive archive, ZipCentralDirectoryFileHeader cd)
{
_archive = archive;
_originallyInArchive = true;
_diskNumberStart = cd.DiskNumberStart;
_versionMadeByPlatform = ( ZipVersionMadeByPlatform )cd.VersionMadeByCompatibility;
_versionMadeBySpecification = ( ZipVersionNeededValues )cd.VersionMadeBySpecification;
_versionToExtract = ( ZipVersionNeededValues )cd.VersionNeededToExtract;
_generalPurposeBitFlag = ( BitFlagValues )cd.GeneralPurposeBitFlag;
CompressionMethod = ( CompressionMethodValues )cd.CompressionMethod;
_lastModified = new DateTimeOffset(ZipHelper.DosTimeToDateTime(cd.LastModified));
_compressedSize = cd.CompressedSize;
_uncompressedSize = cd.UncompressedSize;
_externalFileAttr = cd.ExternalFileAttributes;
_offsetOfLocalHeader = cd.RelativeOffsetOfLocalHeader;
// we don't know this yet: should be _offsetOfLocalHeader + 30 + _storedEntryNameBytes.Length + extrafieldlength
// but entryname/extra length could be different in LH
_storedOffsetOfCompressedData = null;
_crc32 = cd.Crc32;
_compressedBytes = null;
_storedUncompressedData = null;
_currentlyOpenForWrite = false;
_everOpenedForWrite = false;
_outstandingWriteStream = null;
FullName = DecodeEntryName(cd.Filename);
_lhUnknownExtraFields = null;
// the cd should have these as null if we aren't in Update mode
_cdUnknownExtraFields = cd.ExtraFields;
_fileComment = cd.FileComment;
_compressionLevel = null;
}
// if saveExtraFieldsAndComments is false, FileComment and ExtraFields will be null
// in either case, the zip64 extra field info will be incorporated into other fields
public static bool TryReadBlock(BinaryReader reader, bool saveExtraFieldsAndComments, out ZipCentralDirectoryFileHeader header)
{
header = new ZipCentralDirectoryFileHeader();
if (reader.ReadUInt32() != SignatureConstant)
{
return(false);
}
header.VersionMadeBySpecification = reader.ReadByte();
header.VersionMadeByCompatibility = reader.ReadByte();
header.VersionNeededToExtract = reader.ReadUInt16();
header.GeneralPurposeBitFlag = reader.ReadUInt16();
header.CompressionMethod = reader.ReadUInt16();
header.LastModified = reader.ReadUInt32();
header.Crc32 = reader.ReadUInt32();
uint compressedSizeSmall = reader.ReadUInt32();
uint uncompressedSizeSmall = reader.ReadUInt32();
header.FilenameLength = reader.ReadUInt16();
header.ExtraFieldLength = reader.ReadUInt16();
header.FileCommentLength = reader.ReadUInt16();
ushort diskNumberStartSmall = reader.ReadUInt16();
header.InternalFileAttributes = reader.ReadUInt16();
header.ExternalFileAttributes = reader.ReadUInt32();
uint relativeOffsetOfLocalHeaderSmall = reader.ReadUInt32();
header.Filename = reader.ReadBytes(header.FilenameLength);
bool uncompressedSizeInZip64 = uncompressedSizeSmall == ZipHelper.Mask32Bit;
bool compressedSizeInZip64 = compressedSizeSmall == ZipHelper.Mask32Bit;
bool relativeOffsetInZip64 = relativeOffsetOfLocalHeaderSmall == ZipHelper.Mask32Bit;
bool diskNumberStartInZip64 = diskNumberStartSmall == ZipHelper.Mask16Bit;
Zip64ExtraField zip64;
long endExtraFields = reader.BaseStream.Position + header.ExtraFieldLength;
using (Stream str = new SubReadStream(reader.BaseStream, reader.BaseStream.Position, header.ExtraFieldLength))
{
if (saveExtraFieldsAndComments)
{
header.ExtraFields = ZipGenericExtraField.ParseExtraField(str);
zip64 = Zip64ExtraField.GetAndRemoveZip64Block(header.ExtraFields,
uncompressedSizeInZip64, compressedSizeInZip64,
relativeOffsetInZip64, diskNumberStartInZip64);
}
else
{
header.ExtraFields = null;
zip64 = Zip64ExtraField.GetJustZip64Block(str,
uncompressedSizeInZip64, compressedSizeInZip64,
relativeOffsetInZip64, diskNumberStartInZip64);
}
}
// There are zip files that have malformed ExtraField blocks in which GetJustZip64Block() silently bails out without reading all the way to the end
// of the ExtraField block. Thus we must force the stream's position to the proper place.
reader.BaseStream.AdvanceToPosition(endExtraFields);
if (saveExtraFieldsAndComments)
{
header.FileComment = reader.ReadBytes(header.FileCommentLength);
}
else
{
reader.BaseStream.Position += header.FileCommentLength;
header.FileComment = null;
}
header.UncompressedSize = zip64.UncompressedSize == null
? uncompressedSizeSmall
: zip64.UncompressedSize.Value;
header.CompressedSize = zip64.CompressedSize == null
? compressedSizeSmall
: zip64.CompressedSize.Value;
header.RelativeOffsetOfLocalHeader = zip64.LocalHeaderOffset == null
? relativeOffsetOfLocalHeaderSmall
: zip64.LocalHeaderOffset.Value;
header.DiskNumberStart = zip64.StartDiskNumber == null
? diskNumberStartSmall
: zip64.StartDiskNumber.Value;
return(true);
}