/// <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
Ionic.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 void ReadCentralDirectory(ZipFile zf)
{
// We must have the central directory footer record, in order to properly
// read zip dir entries from the central directory. This because the logic
// knows when to open a spanned file when the volume number for the central
// directory differs from the volume number for the zip entry. The
// _diskNumberWithCd was set when originally finding the offset for the
// start of the Central Directory.
// workitem 9214
bool inputUsesZip64 = false;
ZipEntry de;
// in lieu of hashset, use a dictionary
var previouslySeen = new Dictionary <String, object>();
while ((de = ZipEntry.ReadDirEntry(zf, previouslySeen)) != null)
{
de.ResetDirEntry();
zf.OnReadEntry(true, null);
if (zf.Verbose)
{
zf.StatusMessageTextWriter.WriteLine("entry {0}", de.FileName);
}
zf._entries.Add(de.FileName, de);
// workitem 9214
if (de._InputUsesZip64)
{
inputUsesZip64 = true;
}
previouslySeen.Add(de.FileName, null); // to prevent dupes
}
// workitem 9214; auto-set the zip64 flag
if (inputUsesZip64)
{
zf.UseZip64WhenSaving = Zip64Option.Always;
}
// 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);
}
// We keep the read stream open after reading.
if (zf.Verbose)
{
zf.StatusMessageTextWriter.WriteLine("read in {0} entries.", zf._entries.Count);
}
zf.OnReadCompleted();
}
private static void ReadCentralDirectory(ZipFile zf)
{
// We must have the central directory footer record, in order to properly
// read zip dir entries from the central directory. This because the logic
// knows when to open a spanned file when the volume number for the central
// directory differs from the volume number for the zip entry. The
// _diskNumberWithCd was set when originally finding the offset for the
// start of the Central Directory.
// workitem 9214
bool inputUsesZip64 = false;
ZipEntry de;
// in lieu of hashset, use a dictionary
var previouslySeen = new Dictionary<String,object>();
while ((de = ZipEntry.ReadDirEntry(zf, previouslySeen)) != null)
{
de.ResetDirEntry();
zf.OnReadEntry(true, null);
if (zf.Verbose)
zf.StatusMessageTextWriter.WriteLine("entry {0}", de.FileName);
zf._entries.Add(de.FileName,de);
// workitem 9214
if (de._InputUsesZip64) inputUsesZip64 = true;
previouslySeen.Add(de.FileName, null); // to prevent dupes
}
// workitem 9214; auto-set the zip64 flag
if (inputUsesZip64) zf.UseZip64WhenSaving = Zip64Option.Always;
// 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);
// We keep the read stream open after reading.
if (zf.Verbose)
zf.StatusMessageTextWriter.WriteLine("read in {0} entries.", zf._entries.Count);
zf.OnReadCompleted();
}
