/// <summary>
/// Reads one <c>ZipEntry</c> from the given stream. The content for
/// the entry does not get decompressed or decrypted. This method
/// basically reads metadata, and seeks.
/// </summary>
/// <param name="zc">the ZipContainer this entry belongs to.</param>
/// <param name="first">
/// true of this is the first entry being read from the stream.
/// </param>
/// <returns>the <c>ZipEntry</c> read from the stream.</returns>
internal static ZipEntry ReadEntry(ZipContainer zc, bool first)
{
ZipFile zf = zc.ZipFile;
Stream s = zc.ReadStream;
System.Text.Encoding defaultEncoding = zc.AlternateEncoding;
ZipEntry entry = new ZipEntry();
entry._Source = ZipEntrySource.ZipFile;
entry._container = zc;
entry._archiveStream = s;
if (zf != null)
zf.OnReadEntry(true, null);
if (first) HandlePK00Prefix(s);
// Read entry header, including any encryption header
if (!ReadHeader(entry, defaultEncoding)) return null;
// Store the position in the stream for this entry
// change for workitem 8098
entry.__FileDataPosition = entry.ArchiveStream.Position;
// seek past the data without reading it. We will read on Extract()
s.Seek(entry._CompressedFileDataSize + entry._LengthOfTrailer, SeekOrigin.Current);
// workitem 10178
Alienlab.Zip.SharedUtilities.Workaround_Ladybug318918(s);
// ReadHeader moves the file pointer to the end of the entry header,
// as well as any encryption header.
// CompressedFileDataSize includes:
// the maybe compressed, maybe encrypted file data
// the encryption trailer, if any
// the bit 3 descriptor, if any
// workitem 5306
// http://www.codeplex.com/DotNetZip/WorkItem/View.aspx?WorkItemId=5306
HandleUnexpectedDataDescriptor(entry);
if (zf != null)
{
zf.OnReadBytes(entry);
zf.OnReadEntry(false, entry);
}
return entry;
}
private static byte[] GenCentralDirectoryFooter(long StartOfCentralDirectory,
long EndOfCentralDirectory,
Zip64Option zip64,
int entryCount,
string comment,
ZipContainer container)
{
System.Text.Encoding encoding = GetEncoding(container, comment);
int j = 0;
int bufferLength = 22;
byte[] block = null;
Int16 commentLength = 0;
if ((comment != null) && (comment.Length != 0))
{
block = encoding.GetBytes(comment);
commentLength = (Int16)block.Length;
}
bufferLength += commentLength;
byte[] bytes = new byte[bufferLength];
int i = 0;
// signature
byte[] sig = BitConverter.GetBytes(ZipConstants.EndOfCentralDirectorySignature);
Array.Copy(sig, 0, bytes, i, 4);
i+=4;
// number of this disk
// (this number may change later)
bytes[i++] = 0;
bytes[i++] = 0;
// number of the disk with the start of the central directory
// (this number may change later)
bytes[i++] = 0;
bytes[i++] = 0;
// handle ZIP64 extensions for the end-of-central-directory
if (entryCount >= 0xFFFF || zip64 == Zip64Option.Always)
{
// the ZIP64 version.
for (j = 0; j < 4; j++)
bytes[i++] = 0xFF;
}
else
{
// the standard version.
// total number of entries in the central dir on this disk
bytes[i++] = (byte)(entryCount & 0x00FF);
bytes[i++] = (byte)((entryCount & 0xFF00) >> 8);
// total number of entries in the central directory
bytes[i++] = (byte)(entryCount & 0x00FF);
bytes[i++] = (byte)((entryCount & 0xFF00) >> 8);
}
// size of the central directory
Int64 SizeOfCentralDirectory = EndOfCentralDirectory - StartOfCentralDirectory;
if (SizeOfCentralDirectory >= 0xFFFFFFFF || StartOfCentralDirectory >= 0xFFFFFFFF)
{
// The actual data is in the ZIP64 central directory structure
for (j = 0; j < 8; j++)
bytes[i++] = 0xFF;
}
else
{
// size of the central directory (we just get the low 4 bytes)
bytes[i++] = (byte)(SizeOfCentralDirectory & 0x000000FF);
bytes[i++] = (byte)((SizeOfCentralDirectory & 0x0000FF00) >> 8);
bytes[i++] = (byte)((SizeOfCentralDirectory & 0x00FF0000) >> 16);
bytes[i++] = (byte)((SizeOfCentralDirectory & 0xFF000000) >> 24);
// offset of the start of the central directory (we just get the low 4 bytes)
bytes[i++] = (byte)(StartOfCentralDirectory & 0x000000FF);
bytes[i++] = (byte)((StartOfCentralDirectory & 0x0000FF00) >> 8);
bytes[i++] = (byte)((StartOfCentralDirectory & 0x00FF0000) >> 16);
bytes[i++] = (byte)((StartOfCentralDirectory & 0xFF000000) >> 24);
}
// zip archive comment
if ((comment == null) || (comment.Length == 0))
{
// no comment!
bytes[i++] = (byte)0;
bytes[i++] = (byte)0;
}
else
{
// the size of our buffer defines the max length of the comment we can write
if (commentLength + i + 2 > bytes.Length) commentLength = (Int16)(bytes.Length - i - 2);
bytes[i++] = (byte)(commentLength & 0x00FF);
bytes[i++] = (byte)((commentLength & 0xFF00) >> 8);
if (commentLength != 0)
{
// now actually write the comment itself into the byte buffer
for (j = 0; (j < commentLength) && (i + j < bytes.Length); j++)
{
bytes[i + j] = block[j];
}
i += j;
}
}
// s.Write(bytes, 0, i);
return bytes;
}
private static System.Text.Encoding GetEncoding(ZipContainer container, string t)
{
switch (container.AlternateEncodingUsage)
{
case ZipOption.Always:
return container.AlternateEncoding;
case ZipOption.Never:
return container.DefaultEncoding;
}
// AsNecessary is in force
var e = container.DefaultEncoding;
if (t == null) return e;
var bytes = e.GetBytes(t);
var t2 = e.GetString(bytes,0,bytes.Length);
if (t2.Equals(t)) return e;
return container.AlternateEncoding;
}
public static bool WriteCentralDirectoryStructure(Stream s,
ICollection<ZipEntry> entries,
uint numSegments,
Zip64Option zip64,
String comment,
ZipContainer container)
{
var zss = s as ZipSegmentedStream;
if (zss != null)
zss.ContiguousWrite = true;
// write to a memory stream in order to keep the
// CDR contiguous
Int64 aLength = 0;
using (var ms = new MemoryStream())
{
foreach (ZipEntry e in entries)
{
if (e.IncludedInMostRecentSave)
{
// this writes a ZipDirEntry corresponding to the ZipEntry
e.WriteCentralDirectoryEntry(ms);
}
}
var a = ms.ToArray();
s.Write(a, 0, a.Length);
aLength = a.Length;
}
// We need to keep track of the start and
// Finish of the Central Directory Structure.
// Cannot always use WriteStream.Length or Position; some streams do
// not support these. (eg, ASP.NET Response.OutputStream) In those
// cases we have a CountingStream.
// Also, we cannot just set Start as s.Position bfore the write, and Finish
// as s.Position after the write. In a split zip, the write may actually
// flip to the next segment. In that case, Start will be zero. But we
// don't know that til after we know the size of the thing to write. So the
// answer is to compute the directory, then ask the ZipSegmentedStream which
// segment that directory would fall in, it it were written. Then, include
// that data into the directory, and finally, write the directory to the
// output stream.
var output = s as CountingStream;
long Finish = (output != null) ? output.ComputedPosition : s.Position; // BytesWritten
long Start = Finish - aLength;
// need to know which segment the EOCD record starts in
UInt32 startSegment = (zss != null)
? zss.CurrentSegment
: 0;
Int64 SizeOfCentralDirectory = Finish - Start;
int countOfEntries = CountEntries(entries);
bool needZip64CentralDirectory =
zip64 == Zip64Option.Always ||
countOfEntries >= 0xFFFF ||
SizeOfCentralDirectory > 0xFFFFFFFF ||
Start > 0xFFFFFFFF;
byte[] a2 = null;
// emit ZIP64 extensions as required
if (needZip64CentralDirectory)
{
if (zip64 == Zip64Option.Never)
{
#if NETCF
throw new ZipException("The archive requires a ZIP64 Central Directory. Consider enabling ZIP64 extensions.");
#else
System.Diagnostics.StackFrame sf = new System.Diagnostics.StackFrame(1);
if (sf.GetMethod().DeclaringType == typeof(ZipFile))
throw new ZipException("The archive requires a ZIP64 Central Directory. Consider setting the ZipFile.UseZip64WhenSaving property.");
else
throw new ZipException("The archive requires a ZIP64 Central Directory. Consider setting the ZipOutputStream.EnableZip64 property.");
#endif
}
var a = GenZip64EndOfCentralDirectory(Start, Finish, countOfEntries, numSegments);
a2 = GenCentralDirectoryFooter(Start, Finish, zip64, countOfEntries, comment, container);
if (startSegment != 0)
{
UInt32 thisSegment = zss.ComputeSegment(a.Length + a2.Length);
int i = 16;
// number of this disk
Array.Copy(BitConverter.GetBytes(thisSegment), 0, a, i, 4);
i += 4;
// number of the disk with the start of the central directory
//Array.Copy(BitConverter.GetBytes(startSegment), 0, a, i, 4);
Array.Copy(BitConverter.GetBytes(thisSegment), 0, a, i, 4);
i = 60;
// offset 60
// number of the disk with the start of the zip64 eocd
Array.Copy(BitConverter.GetBytes(thisSegment), 0, a, i, 4);
i += 4;
i += 8;
// offset 72
// total number of disks
Array.Copy(BitConverter.GetBytes(thisSegment), 0, a, i, 4);
}
s.Write(a, 0, a.Length);
}
else
a2 = GenCentralDirectoryFooter(Start, Finish, zip64, countOfEntries, comment, container);
// now, the regular footer
if (startSegment != 0)
{
// The assumption is the central directory is never split across
// segment boundaries.
UInt16 thisSegment = (UInt16) zss.ComputeSegment(a2.Length);
int i = 4;
// number of this disk
Array.Copy(BitConverter.GetBytes(thisSegment), 0, a2, i, 2);
i += 2;
// number of the disk with the start of the central directory
//Array.Copy(BitConverter.GetBytes((UInt16)startSegment), 0, a2, i, 2);
Array.Copy(BitConverter.GetBytes(thisSegment), 0, a2, i, 2);
i += 2;
}
s.Write(a2, 0, a2.Length);
// reset the contiguous write property if necessary
if (zss != null)
zss.ContiguousWrite = false;
return needZip64CentralDirectory;
}
private void _Init(Stream stream, bool leaveOpen, string name)
{
_inputStream = stream;
if (!_inputStream.CanRead)
throw new ZipException("The stream must be readable.");
_container= new ZipContainer(this);
_provisionalAlternateEncoding = System.Text.Encoding.GetEncoding("IBM437");
_leaveUnderlyingStreamOpen = leaveOpen;
_findRequired= true;
_name = name ?? "(stream)";
}
// build the TOC by reading each entry in the file.
private static void ReadIntoInstance_Orig(ZipFile zf)
{
zf.OnReadStarted();
//zf._entries = new System.Collections.Generic.List<ZipEntry>();
zf._entries = new System.Collections.Generic.Dictionary<String,ZipEntry>();
ZipEntry e;
if (zf.Verbose)
if (zf.Name == null)
zf.StatusMessageTextWriter.WriteLine("Reading zip from stream...");
else
zf.StatusMessageTextWriter.WriteLine("Reading zip {0}...", zf.Name);
// work item 6647: PK00 (packed to removable disk)
bool firstEntry = true;
ZipContainer zc = new ZipContainer(zf);
while ((e = ZipEntry.ReadEntry(zc, firstEntry)) != null)
{
if (zf.Verbose)
zf.StatusMessageTextWriter.WriteLine(" {0}", e.FileName);
zf._entries.Add(e.FileName,e);
firstEntry = false;
}
// read the zipfile's central directory structure here.
// workitem 9912
// But, because it may be corrupted, ignore errors.
try
{
ZipEntry de;
// in lieu of hashset, use a dictionary
var previouslySeen = new Dictionary<String,Object>();
while ((de = ZipEntry.ReadDirEntry(zf, previouslySeen)) != null)
{
// Housekeeping: Since ZipFile exposes ZipEntry elements in the enumerator,
// we need to copy the comment that we grab from the ZipDirEntry
// into the ZipEntry, so the application can access the comment.
// Also since ZipEntry is used to Write zip files, we need to copy the
// file attributes to the ZipEntry as appropriate.
ZipEntry e1 = zf._entries[de.FileName];
if (e1 != null)
{
e1._Comment = de.Comment;
if (de.IsDirectory) e1.MarkAsDirectory();
}
previouslySeen.Add(de.FileName,null); // to prevent dupes
}
// workitem 8299
if (zf._locEndOfCDS > 0)
zf.ReadStream.Seek(zf._locEndOfCDS, SeekOrigin.Begin);
ReadCentralDirectoryFooter(zf);
if (zf.Verbose && !String.IsNullOrEmpty(zf.Comment))
zf.StatusMessageTextWriter.WriteLine("Zip file Comment: {0}", zf.Comment);
}
catch (ZipException) { }
catch (IOException) { }
zf.OnReadCompleted();
}