old_flsystem/类库/OnlineRepair/ZIP/Zip/ZipOutputStream.cs

901 lines
26 KiB
C#

// ZipOutputStream.cs
//
// Copyright (C) 2001 Mike Krueger
// Copyright (C) 2004 John Reilly
//
// This file was translated from java, it was part of the GNU Classpath
// Copyright (C) 2001 Free Software Foundation, Inc.
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
//
// Linking this library statically or dynamically with other modules is
// making a combined work based on this library. Thus, the terms and
// conditions of the GNU General Public License cover the whole
// combination.
//
// As a special exception, the copyright holders of this library give you
// permission to link this library with independent modules to produce an
// executable, regardless of the license terms of these independent
// modules, and to copy and distribute the resulting executable under
// terms of your choice, provided that you also meet, for each linked
// independent module, the terms and conditions of the license of that
// module. An independent module is a module which is not derived from
// or based on this library. If you modify this library, you may extend
// this exception to your version of the library, but you are not
// obligated to do so. If you do not wish to do so, delete this
// exception statement from your version.
// HISTORY
// 22-12-2009 Z-1649 Added AES support
// 22-02-2010 Z-1648 Zero byte entries would create invalid zip files
using System;
using System.IO;
using System.Collections;
using ICSharpCode.SharpZipLib.Checksums;
using ICSharpCode.SharpZipLib.Zip.Compression;
using ICSharpCode.SharpZipLib.Zip.Compression.Streams;
namespace ICSharpCode.SharpZipLib.Zip
{
/// <summary>
/// This is a DeflaterOutputStream that writes the files into a zip
/// archive one after another. It has a special method to start a new
/// zip entry. The zip entries contains information about the file name
/// size, compressed size, CRC, etc.
///
/// It includes support for Stored and Deflated entries.
/// This class is not thread safe.
/// <br/>
/// <br/>Author of the original java version : Jochen Hoenicke
/// </summary>
/// <example> This sample shows how to create a zip file
/// <code>
/// using System;
/// using System.IO;
///
/// using ICSharpCode.SharpZipLib.Core;
/// using ICSharpCode.SharpZipLib.Zip;
///
/// class MainClass
/// {
/// public static void Main(string[] args)
/// {
/// string[] filenames = Directory.GetFiles(args[0]);
/// byte[] buffer = new byte[4096];
///
/// using ( ZipOutputStream s = new ZipOutputStream(File.Create(args[1])) ) {
///
/// s.SetLevel(9); // 0 - store only to 9 - means best compression
///
/// foreach (string file in filenames) {
/// ZipEntry entry = new ZipEntry(file);
/// s.PutNextEntry(entry);
///
/// using (FileStream fs = File.OpenRead(file)) {
/// StreamUtils.Copy(fs, s, buffer);
/// }
/// }
/// }
/// }
/// }
/// </code>
/// </example>
public class ZipOutputStream : DeflaterOutputStream
{
#region Constructors
/// <summary>
/// Creates a new Zip output stream, writing a zip archive.
/// </summary>
/// <param name="baseOutputStream">
/// The output stream to which the archive contents are written.
/// </param>
public ZipOutputStream(Stream baseOutputStream)
: base(baseOutputStream, new Deflater(Deflater.DEFAULT_COMPRESSION, true))
{
}
/// <summary>
/// Creates a new Zip output stream, writing a zip archive.
/// </summary>
/// <param name="baseOutputStream">The output stream to which the archive contents are written.</param>
/// <param name="bufferSize">Size of the buffer to use.</param>
public ZipOutputStream( Stream baseOutputStream, int bufferSize )
: base(baseOutputStream, new Deflater(Deflater.DEFAULT_COMPRESSION, true), bufferSize)
{
}
#endregion
/// <summary>
/// Gets a flag value of true if the central header has been added for this archive; false if it has not been added.
/// </summary>
/// <remarks>No further entries can be added once this has been done.</remarks>
public bool IsFinished
{
get {
return entries == null;
}
}
/// <summary>
/// Set the zip file comment.
/// </summary>
/// <param name="comment">
/// The comment text for the entire archive.
/// </param>
/// <exception name ="ArgumentOutOfRangeException">
/// The converted comment is longer than 0xffff bytes.
/// </exception>
public void SetComment(string comment)
{
// TODO: Its not yet clear how to handle unicode comments here.
byte[] commentBytes = ZipConstants.ConvertToArray(comment);
if (commentBytes.Length > 0xffff) {
throw new ArgumentOutOfRangeException("comment");
}
zipComment = commentBytes;
}
/// <summary>
/// Sets the compression level. The new level will be activated
/// immediately.
/// </summary>
/// <param name="level">The new compression level (1 to 9).</param>
/// <exception cref="ArgumentOutOfRangeException">
/// Level specified is not supported.
/// </exception>
/// <see cref="ICSharpCode.SharpZipLib.Zip.Compression.Deflater"/>
public void SetLevel(int level)
{
deflater_.SetLevel(level);
defaultCompressionLevel = level;
}
/// <summary>
/// Get the current deflater compression level
/// </summary>
/// <returns>The current compression level</returns>
public int GetLevel()
{
return deflater_.GetLevel();
}
/// <summary>
/// Get / set a value indicating how Zip64 Extension usage is determined when adding entries.
/// </summary>
/// <remarks>Older archivers may not understand Zip64 extensions.
/// If backwards compatability is an issue be careful when adding <see cref="ZipEntry.Size">entries</see> to an archive.
/// Setting this property to off is workable but less desirable as in those circumstances adding a file
/// larger then 4GB will fail.</remarks>
public UseZip64 UseZip64
{
get { return useZip64_; }
set { useZip64_ = value; }
}
/// <summary>
/// Write an unsigned short in little endian byte order.
/// </summary>
private void WriteLeShort(int value)
{
unchecked {
baseOutputStream_.WriteByte((byte)(value & 0xff));
baseOutputStream_.WriteByte((byte)((value >> 8) & 0xff));
}
}
/// <summary>
/// Write an int in little endian byte order.
/// </summary>
private void WriteLeInt(int value)
{
unchecked {
WriteLeShort(value);
WriteLeShort(value >> 16);
}
}
/// <summary>
/// Write an int in little endian byte order.
/// </summary>
private void WriteLeLong(long value)
{
unchecked {
WriteLeInt((int)value);
WriteLeInt((int)(value >> 32));
}
}
/// <summary>
/// Starts a new Zip entry. It automatically closes the previous
/// entry if present.
/// All entry elements bar name are optional, but must be correct if present.
/// If the compression method is stored and the output is not patchable
/// the compression for that entry is automatically changed to deflate level 0
/// </summary>
/// <param name="entry">
/// the entry.
/// </param>
/// <exception cref="System.ArgumentNullException">
/// if entry passed is null.
/// </exception>
/// <exception cref="System.IO.IOException">
/// if an I/O error occured.
/// </exception>
/// <exception cref="System.InvalidOperationException">
/// if stream was finished
/// </exception>
/// <exception cref="ZipException">
/// Too many entries in the Zip file<br/>
/// Entry name is too long<br/>
/// Finish has already been called<br/>
/// </exception>
public void PutNextEntry(ZipEntry entry)
{
if ( entry == null ) {
throw new ArgumentNullException("entry");
}
if (entries == null) {
throw new InvalidOperationException("ZipOutputStream was finished");
}
if (curEntry != null) {
CloseEntry();
}
if (entries.Count == int.MaxValue) {
throw new ZipException("Too many entries for Zip file");
}
CompressionMethod method = entry.CompressionMethod;
int compressionLevel = defaultCompressionLevel;
// Clear flags that the library manages internally
entry.Flags &= (int)GeneralBitFlags.UnicodeText;
patchEntryHeader = false;
bool headerInfoAvailable;
// No need to compress - definitely no data.
if (entry.Size == 0)
{
entry.CompressedSize = entry.Size;
entry.Crc = 0;
method = CompressionMethod.Stored;
headerInfoAvailable = true;
}
else
{
headerInfoAvailable = (entry.Size >= 0) && entry.HasCrc;
// Switch to deflation if storing isnt possible.
if (method == CompressionMethod.Stored)
{
if (!headerInfoAvailable)
{
if (!CanPatchEntries)
{
// Can't patch entries so storing is not possible.
method = CompressionMethod.Deflated;
compressionLevel = 0;
}
}
else // entry.size must be > 0
{
entry.CompressedSize = entry.Size;
headerInfoAvailable = entry.HasCrc;
}
}
}
if (headerInfoAvailable == false) {
if (CanPatchEntries == false) {
// Only way to record size and compressed size is to append a data descriptor
// after compressed data.
// Stored entries of this form have already been converted to deflating.
entry.Flags |= 8;
} else {
patchEntryHeader = true;
}
}
if (Password != null) {
entry.IsCrypted = true;
if (entry.Crc < 0) {
// Need to append a data descriptor as the crc isnt available for use
// with encryption, the date is used instead. Setting the flag
// indicates this to the decompressor.
entry.Flags |= 8;
}
}
entry.Offset = offset;
entry.CompressionMethod = (CompressionMethod)method;
curMethod = method;
sizePatchPos = -1;
if ( (useZip64_ == UseZip64.On) || ((entry.Size < 0) && (useZip64_ == UseZip64.Dynamic)) ) {
entry.ForceZip64();
}
// Write the local file header
WriteLeInt(ZipConstants.LocalHeaderSignature);
WriteLeShort(entry.Version);
WriteLeShort(entry.Flags);
WriteLeShort((byte)entry.CompressionMethodForHeader);
WriteLeInt((int)entry.DosTime);
// TODO: Refactor header writing. Its done in several places.
if (headerInfoAvailable == true) {
WriteLeInt((int)entry.Crc);
if ( entry.LocalHeaderRequiresZip64 ) {
WriteLeInt(-1);
WriteLeInt(-1);
}
else {
WriteLeInt(entry.IsCrypted ? (int)entry.CompressedSize + ZipConstants.CryptoHeaderSize : (int)entry.CompressedSize);
WriteLeInt((int)entry.Size);
}
} else {
if (patchEntryHeader) {
crcPatchPos = baseOutputStream_.Position;
}
WriteLeInt(0); // Crc
if ( patchEntryHeader ) {
sizePatchPos = baseOutputStream_.Position;
}
// For local header both sizes appear in Zip64 Extended Information
if ( entry.LocalHeaderRequiresZip64 || patchEntryHeader ) {
WriteLeInt(-1);
WriteLeInt(-1);
}
else {
WriteLeInt(0); // Compressed size
WriteLeInt(0); // Uncompressed size
}
}
byte[] name = ZipConstants.ConvertToArray(entry.Flags, entry.Name);
if (name.Length > 0xFFFF) {
throw new ZipException("Entry name too long.");
}
ZipExtraData ed = new ZipExtraData(entry.ExtraData);
if (entry.LocalHeaderRequiresZip64) {
ed.StartNewEntry();
if (headerInfoAvailable) {
ed.AddLeLong(entry.Size);
ed.AddLeLong(entry.CompressedSize);
}
else {
ed.AddLeLong(-1);
ed.AddLeLong(-1);
}
ed.AddNewEntry(1);
if ( !ed.Find(1) ) {
throw new ZipException("Internal error cant find extra data");
}
if ( patchEntryHeader ) {
sizePatchPos = ed.CurrentReadIndex;
}
}
else {
ed.Delete(1);
}
#if !NET_1_1 && !NETCF_2_0
if (entry.AESKeySize > 0) {
AddExtraDataAES(entry, ed);
}
#endif
byte[] extra = ed.GetEntryData();
WriteLeShort(name.Length);
WriteLeShort(extra.Length);
if ( name.Length > 0 ) {
baseOutputStream_.Write(name, 0, name.Length);
}
if ( entry.LocalHeaderRequiresZip64 && patchEntryHeader ) {
sizePatchPos += baseOutputStream_.Position;
}
if ( extra.Length > 0 ) {
baseOutputStream_.Write(extra, 0, extra.Length);
}
offset += ZipConstants.LocalHeaderBaseSize + name.Length + extra.Length;
// Fix offsetOfCentraldir for AES
if (entry.AESKeySize > 0)
offset += entry.AESOverheadSize;
// Activate the entry.
curEntry = entry;
crc.Reset();
if (method == CompressionMethod.Deflated) {
deflater_.Reset();
deflater_.SetLevel(compressionLevel);
}
size = 0;
if (entry.IsCrypted) {
#if !NET_1_1 && !NETCF_2_0
if (entry.AESKeySize > 0) {
WriteAESHeader(entry);
} else
#endif
{
if (entry.Crc < 0) { // so testing Zip will says its ok
WriteEncryptionHeader(entry.DosTime << 16);
} else {
WriteEncryptionHeader(entry.Crc);
}
}
}
}
/// <summary>
/// Closes the current entry, updating header and footer information as required
/// </summary>
/// <exception cref="System.IO.IOException">
/// An I/O error occurs.
/// </exception>
/// <exception cref="System.InvalidOperationException">
/// No entry is active.
/// </exception>
public void CloseEntry()
{
if (curEntry == null) {
throw new InvalidOperationException("No open entry");
}
long csize = size;
// First finish the deflater, if appropriate
if (curMethod == CompressionMethod.Deflated) {
if (size >= 0) {
base.Finish();
csize = deflater_.TotalOut;
}
else {
deflater_.Reset();
}
}
// Write the AES Authentication Code (a hash of the compressed and encrypted data)
if (curEntry.AESKeySize > 0) {
baseOutputStream_.Write(AESAuthCode, 0, 10);
}
if (curEntry.Size < 0) {
curEntry.Size = size;
} else if (curEntry.Size != size) {
throw new ZipException("size was " + size + ", but I expected " + curEntry.Size);
}
if (curEntry.CompressedSize < 0) {
curEntry.CompressedSize = csize;
} else if (curEntry.CompressedSize != csize) {
throw new ZipException("compressed size was " + csize + ", but I expected " + curEntry.CompressedSize);
}
if (curEntry.Crc < 0) {
curEntry.Crc = crc.Value;
} else if (curEntry.Crc != crc.Value) {
throw new ZipException("crc was " + crc.Value + ", but I expected " + curEntry.Crc);
}
offset += csize;
if (curEntry.IsCrypted) {
if (curEntry.AESKeySize > 0) {
curEntry.CompressedSize += curEntry.AESOverheadSize;
} else {
curEntry.CompressedSize += ZipConstants.CryptoHeaderSize;
}
}
// Patch the header if possible
if (patchEntryHeader) {
patchEntryHeader = false;
long curPos = baseOutputStream_.Position;
baseOutputStream_.Seek(crcPatchPos, SeekOrigin.Begin);
WriteLeInt((int)curEntry.Crc);
if ( curEntry.LocalHeaderRequiresZip64 ) {
if ( sizePatchPos == -1 ) {
throw new ZipException("Entry requires zip64 but this has been turned off");
}
baseOutputStream_.Seek(sizePatchPos, SeekOrigin.Begin);
WriteLeLong(curEntry.Size);
WriteLeLong(curEntry.CompressedSize);
}
else {
WriteLeInt((int)curEntry.CompressedSize);
WriteLeInt((int)curEntry.Size);
}
baseOutputStream_.Seek(curPos, SeekOrigin.Begin);
}
// Add data descriptor if flagged as required
if ((curEntry.Flags & 8) != 0) {
WriteLeInt(ZipConstants.DataDescriptorSignature);
WriteLeInt(unchecked((int)curEntry.Crc));
if ( curEntry.LocalHeaderRequiresZip64 ) {
WriteLeLong(curEntry.CompressedSize);
WriteLeLong(curEntry.Size);
offset += ZipConstants.Zip64DataDescriptorSize;
}
else {
WriteLeInt((int)curEntry.CompressedSize);
WriteLeInt((int)curEntry.Size);
offset += ZipConstants.DataDescriptorSize;
}
}
entries.Add(curEntry);
curEntry = null;
}
void WriteEncryptionHeader(long crcValue)
{
offset += ZipConstants.CryptoHeaderSize;
InitializePassword(Password);
byte[] cryptBuffer = new byte[ZipConstants.CryptoHeaderSize];
Random rnd = new Random();
rnd.NextBytes(cryptBuffer);
cryptBuffer[11] = (byte)(crcValue >> 24);
EncryptBlock(cryptBuffer, 0, cryptBuffer.Length);
baseOutputStream_.Write(cryptBuffer, 0, cryptBuffer.Length);
}
#if !NET_1_1 && !NETCF_2_0
private static void AddExtraDataAES(ZipEntry entry, ZipExtraData extraData) {
// Vendor Version: AE-1 IS 1. AE-2 is 2. With AE-2 no CRC is required and 0 is stored.
const int VENDOR_VERSION = 2;
// Vendor ID is the two ASCII characters "AE".
const int VENDOR_ID = 0x4541; //not 6965;
extraData.StartNewEntry();
// Pack AES extra data field see http://www.winzip.com/aes_info.htm
//extraData.AddLeShort(7); // Data size (currently 7)
extraData.AddLeShort(VENDOR_VERSION); // 2 = AE-2
extraData.AddLeShort(VENDOR_ID); // "AE"
extraData.AddData(entry.AESEncryptionStrength); // 1 = 128, 2 = 192, 3 = 256
extraData.AddLeShort((int)entry.CompressionMethod); // The actual compression method used to compress the file
extraData.AddNewEntry(0x9901);
}
// Replaces WriteEncryptionHeader for AES
//
private void WriteAESHeader(ZipEntry entry) {
byte[] salt;
byte[] pwdVerifier;
InitializeAESPassword(entry, Password, out salt, out pwdVerifier);
// File format for AES:
// Size (bytes) Content
// ------------ -------
// Variable Salt value
// 2 Password verification value
// Variable Encrypted file data
// 10 Authentication code
//
// Value in the "compressed size" fields of the local file header and the central directory entry
// is the total size of all the items listed above. In other words, it is the total size of the
// salt value, password verification value, encrypted data, and authentication code.
baseOutputStream_.Write(salt, 0, salt.Length);
baseOutputStream_.Write(pwdVerifier, 0, pwdVerifier.Length);
}
#endif
/// <summary>
/// Writes the given buffer to the current entry.
/// </summary>
/// <param name="buffer">The buffer containing data to write.</param>
/// <param name="offset">The offset of the first byte to write.</param>
/// <param name="count">The number of bytes to write.</param>
/// <exception cref="ZipException">Archive size is invalid</exception>
/// <exception cref="System.InvalidOperationException">No entry is active.</exception>
public override void Write(byte[] buffer, int offset, int count)
{
if (curEntry == null) {
throw new InvalidOperationException("No open entry.");
}
if ( buffer == null ) {
throw new ArgumentNullException("buffer");
}
if ( offset < 0 ) {
#if NETCF_1_0
throw new ArgumentOutOfRangeException("offset");
#else
throw new ArgumentOutOfRangeException("offset", "Cannot be negative");
#endif
}
if ( count < 0 ) {
#if NETCF_1_0
throw new ArgumentOutOfRangeException("count");
#else
throw new ArgumentOutOfRangeException("count", "Cannot be negative");
#endif
}
if ( (buffer.Length - offset) < count ) {
throw new ArgumentException("Invalid offset/count combination");
}
crc.Update(buffer, offset, count);
size += count;
switch (curMethod) {
case CompressionMethod.Deflated:
base.Write(buffer, offset, count);
break;
case CompressionMethod.Stored:
if (Password != null) {
CopyAndEncrypt(buffer, offset, count);
} else {
baseOutputStream_.Write(buffer, offset, count);
}
break;
}
}
void CopyAndEncrypt(byte[] buffer, int offset, int count)
{
const int CopyBufferSize = 4096;
byte[] localBuffer = new byte[CopyBufferSize];
while ( count > 0 ) {
int bufferCount = (count < CopyBufferSize) ? count : CopyBufferSize;
Array.Copy(buffer, offset, localBuffer, 0, bufferCount);
EncryptBlock(localBuffer, 0, bufferCount);
baseOutputStream_.Write(localBuffer, 0, bufferCount);
count -= bufferCount;
offset += bufferCount;
}
}
/// <summary>
/// Finishes the stream. This will write the central directory at the
/// end of the zip file and flush the stream.
/// </summary>
/// <remarks>
/// This is automatically called when the stream is closed.
/// </remarks>
/// <exception cref="System.IO.IOException">
/// An I/O error occurs.
/// </exception>
/// <exception cref="ZipException">
/// Comment exceeds the maximum length<br/>
/// Entry name exceeds the maximum length
/// </exception>
public override void Finish()
{
if (entries == null) {
return;
}
if (curEntry != null) {
CloseEntry();
}
long numEntries = entries.Count;
long sizeEntries = 0;
foreach (ZipEntry entry in entries) {
WriteLeInt(ZipConstants.CentralHeaderSignature);
WriteLeShort(ZipConstants.VersionMadeBy);
WriteLeShort(entry.Version);
WriteLeShort(entry.Flags);
WriteLeShort((short)entry.CompressionMethodForHeader);
WriteLeInt((int)entry.DosTime);
WriteLeInt((int)entry.Crc);
if ( entry.IsZip64Forced() ||
(entry.CompressedSize >= uint.MaxValue) )
{
WriteLeInt(-1);
}
else {
WriteLeInt((int)entry.CompressedSize);
}
if ( entry.IsZip64Forced() ||
(entry.Size >= uint.MaxValue) )
{
WriteLeInt(-1);
}
else {
WriteLeInt((int)entry.Size);
}
byte[] name = ZipConstants.ConvertToArray(entry.Flags, entry.Name);
if (name.Length > 0xffff) {
throw new ZipException("Name too long.");
}
ZipExtraData ed = new ZipExtraData(entry.ExtraData);
if ( entry.CentralHeaderRequiresZip64 ) {
ed.StartNewEntry();
if ( entry.IsZip64Forced() ||
(entry.Size >= 0xffffffff) )
{
ed.AddLeLong(entry.Size);
}
if ( entry.IsZip64Forced() ||
(entry.CompressedSize >= 0xffffffff) )
{
ed.AddLeLong(entry.CompressedSize);
}
if ( entry.Offset >= 0xffffffff )
{
ed.AddLeLong(entry.Offset);
}
ed.AddNewEntry(1);
}
else {
ed.Delete(1);
}
#if !NET_1_1 && !NETCF_2_0
if (entry.AESKeySize > 0) {
AddExtraDataAES(entry, ed);
}
#endif
byte[] extra = ed.GetEntryData();
byte[] entryComment =
(entry.Comment != null) ?
ZipConstants.ConvertToArray(entry.Flags, entry.Comment) :
new byte[0];
if (entryComment.Length > 0xffff) {
throw new ZipException("Comment too long.");
}
WriteLeShort(name.Length);
WriteLeShort(extra.Length);
WriteLeShort(entryComment.Length);
WriteLeShort(0); // disk number
WriteLeShort(0); // internal file attributes
// external file attributes
if (entry.ExternalFileAttributes != -1) {
WriteLeInt(entry.ExternalFileAttributes);
} else {
if (entry.IsDirectory) { // mark entry as directory (from nikolam.AT.perfectinfo.com)
WriteLeInt(16);
} else {
WriteLeInt(0);
}
}
if ( entry.Offset >= uint.MaxValue ) {
WriteLeInt(-1);
}
else {
WriteLeInt((int)entry.Offset);
}
if ( name.Length > 0 ) {
baseOutputStream_.Write(name, 0, name.Length);
}
if ( extra.Length > 0 ) {
baseOutputStream_.Write(extra, 0, extra.Length);
}
if ( entryComment.Length > 0 ) {
baseOutputStream_.Write(entryComment, 0, entryComment.Length);
}
sizeEntries += ZipConstants.CentralHeaderBaseSize + name.Length + extra.Length + entryComment.Length;
}
using ( ZipHelperStream zhs = new ZipHelperStream(baseOutputStream_) ) {
zhs.WriteEndOfCentralDirectory(numEntries, sizeEntries, offset, zipComment);
}
entries = null;
}
#region Instance Fields
/// <summary>
/// The entries for the archive.
/// </summary>
ArrayList entries = new ArrayList();
/// <summary>
/// Used to track the crc of data added to entries.
/// </summary>
Crc32 crc = new Crc32();
/// <summary>
/// The current entry being added.
/// </summary>
ZipEntry curEntry;
int defaultCompressionLevel = Deflater.DEFAULT_COMPRESSION;
CompressionMethod curMethod = CompressionMethod.Deflated;
/// <summary>
/// Used to track the size of data for an entry during writing.
/// </summary>
long size;
/// <summary>
/// Offset to be recorded for each entry in the central header.
/// </summary>
long offset;
/// <summary>
/// Comment for the entire archive recorded in central header.
/// </summary>
byte[] zipComment = new byte[0];
/// <summary>
/// Flag indicating that header patching is required for the current entry.
/// </summary>
bool patchEntryHeader;
/// <summary>
/// Position to patch crc
/// </summary>
long crcPatchPos = -1;
/// <summary>
/// Position to patch size.
/// </summary>
long sizePatchPos = -1;
// Default is dynamic which is not backwards compatible and can cause problems
// with XP's built in compression which cant read Zip64 archives.
// However it does avoid the situation were a large file is added and cannot be completed correctly.
// NOTE: Setting the size for entries before they are added is the best solution!
UseZip64 useZip64_ = UseZip64.Dynamic;
#endregion
}
}