/// <summary>
/// Gets the offset of an archive that is positioned 0 or more bytes
/// from the start of the Stream.
/// </summary>
/// <param name="stream">A stream for reading the archive.</param>
/// <returns>The offset in bytes of the archive,
/// or -1 if no archive is found in the Stream.</returns>
/// <remarks>The archive must begin on a 4-byte boundary.</remarks>
public override long FindArchiveOffset(Stream stream)
{
if (stream == null)
{
throw new ArgumentNullException("stream");
}
long offset = base.FindArchiveOffset(stream);
if (offset > 0)
{
// Some self-extract packages include the exe stub in file offset calculations.
// Check the first header directory offset to decide whether the entire
// archive needs to be offset or not.
ZipEndOfCentralDirectory eocd = this.GetEOCD(null, stream);
if (eocd != null && eocd.totalEntries > 0)
{
stream.Seek(eocd.dirOffset, SeekOrigin.Begin);
ZipFileHeader header = new ZipFileHeader();
if (header.Read(stream, true) && header.localHeaderOffset < stream.Length)
{
stream.Seek(header.localHeaderOffset, SeekOrigin.Begin);
if (header.Read(stream, false))
{
return(0);
}
}
}
}
return(offset);
}
private ZipEndOfCentralDirectory GetEOCD(
IUnpackStreamContext streamContext, Stream archiveStream)
{
BinaryReader reader = new BinaryReader(archiveStream);
long offset = archiveStream.Length
- ZipEndOfCentralDirectory.EOCD_RECORD_FIXEDSIZE;
while (offset >= 0)
{
archiveStream.Seek(offset, SeekOrigin.Begin);
uint sig = reader.ReadUInt32();
if (sig == ZipEndOfCentralDirectory.EOCDSIG)
{
break;
}
offset--;
}
if (offset < 0)
{
return(null);
}
ZipEndOfCentralDirectory eocd = new ZipEndOfCentralDirectory();
archiveStream.Seek(offset, SeekOrigin.Begin);
if (!eocd.Read(archiveStream))
{
throw new ZipException("Invalid end of central directory record");
}
if (eocd.dirOffset == (long)UInt32.MaxValue)
{
string saveComment = eocd.comment;
archiveStream.Seek(
offset - Zip64EndOfCentralDirectoryLocator.EOCDL64_SIZE,
SeekOrigin.Begin);
Zip64EndOfCentralDirectoryLocator eocdl =
new Zip64EndOfCentralDirectoryLocator();
if (!eocdl.Read(archiveStream))
{
throw new ZipException("Missing or invalid end of " +
"central directory record locator");
}
if (eocdl.dirStartDiskNumber == eocdl.totalDisks - 1)
{
// ZIP64 eocd is entirely in current stream.
archiveStream.Seek(eocdl.dirOffset, SeekOrigin.Begin);
if (!eocd.Read(archiveStream))
{
throw new ZipException("Missing or invalid ZIP64 end of " +
"central directory record");
}
}
else if (streamContext == null)
{
return(null);
}
else
{
// TODO: handle EOCD64 spanning archives!
throw new NotImplementedException("Zip implementation does not " +
"handle end of central directory record that spans archives.");
}
eocd.comment = saveComment;
}
return(eocd);
}
/// <summary>
/// Reads all the file headers from the central directory in the main archive.
/// </summary>
private IList <ZipFileHeader> GetCentralDirectory(IUnpackStreamContext streamContext)
{
Stream archiveStream = null;
this.currentArchiveNumber = 0;
try
{
List <ZipFileHeader> headers = new List <ZipFileHeader>();
archiveStream = this.OpenArchive(streamContext, 0);
ZipEndOfCentralDirectory eocd = this.GetEOCD(streamContext, archiveStream);
if (eocd == null)
{
return(null);
}
else if (eocd.totalEntries == 0)
{
return(headers);
}
headers.Capacity = (int)eocd.totalEntries;
if (eocd.dirOffset > archiveStream.Length - ZipFileHeader.CFH_FIXEDSIZE)
{
streamContext.CloseArchiveReadStream(
this.currentArchiveNumber, String.Empty, archiveStream);
archiveStream = null;
}
else
{
archiveStream.Seek(eocd.dirOffset, SeekOrigin.Begin);
uint sig = new BinaryReader(archiveStream).ReadUInt32();
if (sig != ZipFileHeader.CFHSIG)
{
streamContext.CloseArchiveReadStream(
this.currentArchiveNumber, String.Empty, archiveStream);
archiveStream = null;
}
}
if (archiveStream == null)
{
this.currentArchiveNumber = (short)(eocd.dirStartDiskNumber + 1);
archiveStream = streamContext.OpenArchiveReadStream(
this.currentArchiveNumber, String.Empty, this);
if (archiveStream == null)
{
return(null);
}
}
archiveStream.Seek(eocd.dirOffset, SeekOrigin.Begin);
while (headers.Count < eocd.totalEntries)
{
ZipFileHeader header = new ZipFileHeader();
if (!header.Read(archiveStream, true))
{
throw new ZipException(
"Missing or invalid central directory file header");
}
headers.Add(header);
if (headers.Count < eocd.totalEntries &&
archiveStream.Position == archiveStream.Length)
{
streamContext.CloseArchiveReadStream(
this.currentArchiveNumber, String.Empty, archiveStream);
this.currentArchiveNumber++;
archiveStream = streamContext.OpenArchiveReadStream(
this.currentArchiveNumber, String.Empty, this);
if (archiveStream == null)
{
this.currentArchiveNumber = 0;
archiveStream = streamContext.OpenArchiveReadStream(
this.currentArchiveNumber, String.Empty, this);
}
}
}
return(headers);
}
finally
{
if (archiveStream != null)
{
streamContext.CloseArchiveReadStream(
this.currentArchiveNumber, String.Empty, archiveStream);
}
}
}
/// <summary>
/// Creates a zip archive or chain of zip archives.
/// </summary>
/// <param name="streamContext">A context interface to handle opening
/// and closing of archive and file streams.</param>
/// <param name="files">An array of file lists. Each list is
/// compressed into one stream in the archive.</param>
/// <param name="maxArchiveSize">The maximum number of bytes for one archive
/// before the contents are chained to the next archive, or zero for unlimited
/// archive size.</param>
/// <exception cref="ArchiveException">The archive could not be
/// created.</exception>
/// <remarks>
/// The stream context implementation may provide a mapping from the file
/// paths within the archive to the external file paths.
/// </remarks>
public override void Pack(
IPackStreamContext streamContext,
IEnumerable <string> files,
long maxArchiveSize)
{
if (streamContext == null)
{
throw new ArgumentNullException("streamContext");
}
if (files == null)
{
throw new ArgumentNullException("files");
}
lock (this)
{
Stream archiveStream = null;
try
{
this.ResetProgressData();
this.totalArchives = 1;
object forceZip64Value = streamContext.GetOption("forceZip64", null);
bool forceZip64 = Convert.ToBoolean(
forceZip64Value, CultureInfo.InvariantCulture);
// Count the total number of files and bytes to be compressed.
foreach (string file in files)
{
FileAttributes attributes;
DateTime lastWriteTime;
Stream fileStream = streamContext.OpenFileReadStream(
file,
out attributes,
out lastWriteTime);
if (fileStream != null)
{
this.totalFileBytes += fileStream.Length;
this.totalFiles++;
streamContext.CloseFileReadStream(file, fileStream);
}
}
List <ZipFileHeader> fileHeaders = new List <ZipFileHeader>();
this.currentFileNumber = -1;
if (this.currentArchiveName == null)
{
this.mainArchiveName = streamContext.GetArchiveName(0);
this.currentArchiveName = this.mainArchiveName;
if (string.IsNullOrWhiteSpace(this.currentArchiveName))
{
throw new FileNotFoundException("No name provided for archive.");
}
}
this.OnProgress(ArchiveProgressType.StartArchive);
// Compress files one by one, saving header info for each.
foreach (string file in files)
{
ZipFileHeader fileHeader = this.PackOneFile(
streamContext,
file,
maxArchiveSize,
forceZip64,
ref archiveStream);
if (fileHeader != null)
{
fileHeaders.Add(fileHeader);
}
this.currentArchiveTotalBytes = (archiveStream != null ?
archiveStream.Position : 0);
this.currentArchiveBytesProcessed = this.currentArchiveTotalBytes;
}
bool zip64 = forceZip64 || this.totalFiles > UInt16.MaxValue;
// Write the central directory composed of all the file headers.
uint centralDirStartArchiveNumber = 0;
long centralDirStartPosition = 0;
long centralDirSize = 0;
for (int i = 0; i < fileHeaders.Count; i++)
{
ZipFileHeader fileHeader = fileHeaders[i];
int headerSize = fileHeader.GetSize(true);
centralDirSize += headerSize;
this.CheckArchiveWriteStream(
streamContext,
maxArchiveSize,
headerSize,
ref archiveStream);
if (i == 0)
{
centralDirStartArchiveNumber = (uint)this.currentArchiveNumber;
centralDirStartPosition = archiveStream.Position;
}
fileHeader.Write(archiveStream, true);
if (fileHeader.zip64)
{
zip64 = true;
}
}
this.currentArchiveTotalBytes =
(archiveStream != null ? archiveStream.Position : 0);
this.currentArchiveBytesProcessed = this.currentArchiveTotalBytes;
ZipEndOfCentralDirectory eocd = new ZipEndOfCentralDirectory();
eocd.dirStartDiskNumber = centralDirStartArchiveNumber;
eocd.entriesOnDisk = fileHeaders.Count;
eocd.totalEntries = fileHeaders.Count;
eocd.dirSize = centralDirSize;
eocd.dirOffset = centralDirStartPosition;
eocd.comment = this.comment;
Zip64EndOfCentralDirectoryLocator eocdl =
new Zip64EndOfCentralDirectoryLocator();
int maxFooterSize = eocd.GetSize(false);
if (archiveStream != null && (zip64 || archiveStream.Position >
((long)UInt32.MaxValue) - eocd.GetSize(false)))
{
maxFooterSize += eocd.GetSize(true) + (int)
Zip64EndOfCentralDirectoryLocator.EOCDL64_SIZE;
zip64 = true;
}
this.CheckArchiveWriteStream(
streamContext,
maxArchiveSize,
maxFooterSize,
ref archiveStream);
eocd.diskNumber = (uint)this.currentArchiveNumber;
if (zip64)
{
eocd.versionMadeBy = 45;
eocd.versionNeeded = 45;
eocd.zip64 = true;
eocdl.dirOffset = archiveStream.Position;
eocdl.dirStartDiskNumber = (uint)this.currentArchiveNumber;
eocdl.totalDisks = (uint)this.currentArchiveNumber + 1;
eocd.Write(archiveStream);
eocdl.Write(archiveStream);
eocd.dirOffset = UInt32.MaxValue;
eocd.dirStartDiskNumber = UInt16.MaxValue;
}
eocd.zip64 = false;
eocd.Write(archiveStream);
this.currentArchiveTotalBytes = archiveStream.Position;
this.currentArchiveBytesProcessed = this.currentArchiveTotalBytes;
}
finally
{
if (archiveStream != null)
{
streamContext.CloseArchiveWriteStream(
this.currentArchiveNumber, this.mainArchiveName, archiveStream);
this.OnProgress(ArchiveProgressType.FinishArchive);
}
}
}
}