--- /dev/null
+// InflaterInputStream.cs\r
+// Copyright (C) 2001 Mike Krueger\r
+//\r
+// This file was translated from java, it was part of the GNU Classpath\r
+// Copyright (C) 2001 Free Software Foundation, Inc.\r
+//\r
+// This program is free software; you can redistribute it and/or\r
+// modify it under the terms of the GNU General Public License\r
+// as published by the Free Software Foundation; either version 2\r
+// of the License, or (at your option) any later version.\r
+//\r
+// This program is distributed in the hope that it will be useful,\r
+// but WITHOUT ANY WARRANTY; without even the implied warranty of\r
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the\r
+// GNU General Public License for more details.\r
+//\r
+// You should have received a copy of the GNU General Public License\r
+// along with this program; if not, write to the Free Software\r
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.\r
+//\r
+// Linking this library statically or dynamically with other modules is\r
+// making a combined work based on this library. Thus, the terms and\r
+// conditions of the GNU General Public License cover the whole\r
+// combination.\r
+// \r
+// As a special exception, the copyright holders of this library give you\r
+// permission to link this library with independent modules to produce an\r
+// executable, regardless of the license terms of these independent\r
+// modules, and to copy and distribute the resulting executable under\r
+// terms of your choice, provided that you also meet, for each linked\r
+// independent module, the terms and conditions of the license of that\r
+// module. An independent module is a module which is not derived from\r
+// or based on this library. If you modify this library, you may extend\r
+// this exception to your version of the library, but you are not\r
+// obligated to do so. If you do not wish to do so, delete this\r
+// exception statement from your version.\r
+\r
+using System;\r
+using System.IO;\r
+\r
+using ICSharpCode.SharpZipLib.Zip.Compression;\r
+using ICSharpCode.SharpZipLib.Checksums;\r
+\r
+namespace ICSharpCode.SharpZipLib.Zip.Compression.Streams \r
+{\r
+ \r
+ /// <summary>\r
+ /// This filter stream is used to decompress data compressed baseInputStream the "deflate"\r
+ /// format. The "deflate" format is described baseInputStream RFC 1951.\r
+ ///\r
+ /// This stream may form the basis for other decompression filters, such\r
+ /// as the <code>GzipInputStream</code>.\r
+ ///\r
+ /// author of the original java version : John Leuner\r
+ /// </summary>\r
+ public class InflaterInputStream : Stream\r
+ {\r
+ //Variables\r
+ \r
+ /// <summary>\r
+ /// Decompressor for this filter\r
+ /// </summary>\r
+ protected Inflater inf;\r
+ \r
+ /// <summary>\r
+ /// Byte array used as a buffer\r
+ /// </summary>\r
+ protected byte[] buf;\r
+ \r
+ /// <summary>\r
+ /// Size of buffer\r
+ /// </summary>\r
+ protected int len;\r
+ \r
+ //We just use this if we are decoding one byte at a time with the read() call\r
+ private byte[] onebytebuffer = new byte[1];\r
+ \r
+ /// <summary>\r
+ /// base stream the inflater depends on.\r
+ /// </summary>\r
+ protected Stream baseInputStream;\r
+ \r
+ protected long csize;\r
+ \r
+ /// <summary>\r
+ /// I needed to implement the abstract member.\r
+ /// </summary>\r
+ public override bool CanRead {\r
+ get {\r
+ return baseInputStream.CanRead;\r
+ }\r
+ }\r
+ \r
+ /// <summary>\r
+ /// I needed to implement the abstract member.\r
+ /// </summary>\r
+ public override bool CanSeek {\r
+ get {\r
+ return false;\r
+ // return baseInputStream.CanSeek;\r
+ }\r
+ }\r
+ \r
+ /// <summary>\r
+ /// I needed to implement the abstract member.\r
+ /// </summary>\r
+ public override bool CanWrite {\r
+ get {\r
+ return baseInputStream.CanWrite;\r
+ }\r
+ }\r
+ \r
+ /// <summary>\r
+ /// I needed to implement the abstract member.\r
+ /// </summary>\r
+ public override long Length {\r
+ get {\r
+ return len;\r
+ }\r
+ }\r
+ \r
+ /// <summary>\r
+ /// I needed to implement the abstract member.\r
+ /// </summary>\r
+ public override long Position {\r
+ get {\r
+ return baseInputStream.Position;\r
+ }\r
+ set {\r
+ baseInputStream.Position = value;\r
+ }\r
+ }\r
+ \r
+ /// <summary>\r
+ /// Flushes the baseInputStream\r
+ /// </summary>\r
+ public override void Flush()\r
+ {\r
+ baseInputStream.Flush();\r
+ }\r
+ \r
+ /// <summary>\r
+ /// I needed to implement the abstract member.\r
+ /// </summary>\r
+ public override long Seek(long offset, SeekOrigin origin)\r
+ {\r
+ throw new NotSupportedException("Seek not supported"); // -jr- 01-Dec-2003\r
+ }\r
+ \r
+ /// <summary>\r
+ /// I needed to implement the abstract member.\r
+ /// </summary>\r
+ public override void SetLength(long val)\r
+ {\r
+ baseInputStream.SetLength(val);\r
+ }\r
+ \r
+ /// <summary>\r
+ /// I needed to implement the abstract member.\r
+ /// </summary>\r
+ public override void Write(byte[] array, int offset, int count)\r
+ {\r
+ baseInputStream.Write(array, offset, count);\r
+ }\r
+ \r
+ /// <summary>\r
+ /// I needed to implement the abstract member.\r
+ /// </summary>\r
+ public override void WriteByte(byte val)\r
+ {\r
+ baseInputStream.WriteByte(val);\r
+ }\r
+ \r
+ // -jr- 01-Dec-2003 This may be flawed for some base streams? Depends on implementation of BeginWrite\r
+ public override IAsyncResult BeginWrite(byte[] buffer, int offset, int count, AsyncCallback callback, object state)\r
+ {\r
+ throw new NotSupportedException("Asynch write not currently supported");\r
+ }\r
+ \r
+ //Constructors\r
+ \r
+ /// <summary>\r
+ /// Create an InflaterInputStream with the default decompresseor\r
+ /// and a default buffer size.\r
+ /// </summary>\r
+ /// <param name = "baseInputStream">\r
+ /// the InputStream to read bytes from\r
+ /// </param>\r
+ public InflaterInputStream(Stream baseInputStream) : this(baseInputStream, new Inflater(), 4096)\r
+ {\r
+ \r
+ }\r
+ \r
+ /// <summary>\r
+ /// Create an InflaterInputStream with the specified decompresseor\r
+ /// and a default buffer size.\r
+ /// </summary>\r
+ /// <param name = "baseInputStream">\r
+ /// the InputStream to read bytes from\r
+ /// </param>\r
+ /// <param name = "inf">\r
+ /// the decompressor used to decompress data read from baseInputStream\r
+ /// </param>\r
+ public InflaterInputStream(Stream baseInputStream, Inflater inf) : this(baseInputStream, inf, 4096)\r
+ {\r
+ }\r
+ \r
+ /// <summary>\r
+ /// Create an InflaterInputStream with the specified decompresseor\r
+ /// and a specified buffer size.\r
+ /// </summary>\r
+ /// <param name = "baseInputStream">\r
+ /// the InputStream to read bytes from\r
+ /// </param>\r
+ /// <param name = "inf">\r
+ /// the decompressor used to decompress data read from baseInputStream\r
+ /// </param>\r
+ /// <param name = "size">\r
+ /// size of the buffer to use\r
+ /// </param>\r
+ public InflaterInputStream(Stream baseInputStream, Inflater inf, int size)\r
+ {\r
+ this.baseInputStream = baseInputStream;\r
+ this.inf = inf;\r
+ try {\r
+ this.len = (int)baseInputStream.Length;\r
+ } catch (Exception) {\r
+ // the stream may not support .Length\r
+ this.len = 0;\r
+ }\r
+ \r
+ if (size <= 0) {\r
+ throw new ArgumentOutOfRangeException("size <= 0");\r
+ }\r
+ \r
+ buf = new byte[size]; //Create the buffer\r
+ }\r
+ \r
+ //Methods\r
+ \r
+ /// <summary>\r
+ /// Returns 0 once the end of the stream (EOF) has been reached.\r
+ /// Otherwise returns 1.\r
+ /// </summary>\r
+ public virtual int Available {\r
+ get {\r
+ return inf.IsFinished ? 0 : 1;\r
+ }\r
+ }\r
+ \r
+ /// <summary>\r
+ /// Closes the input stream\r
+ /// </summary>\r
+ public override void Close()\r
+ {\r
+ baseInputStream.Close();\r
+ }\r
+ \r
+ /// <summary>\r
+ /// Fills the buffer with more data to decompress.\r
+ /// </summary>\r
+ protected void Fill()\r
+ {\r
+ len = baseInputStream.Read(buf, 0, buf.Length);\r
+ // decrypting crypted data\r
+ if (cryptbuffer != null) {\r
+ DecryptBlock(buf, 0, System.Math.Min((int)(csize - inf.TotalIn), buf.Length));\r
+ }\r
+ \r
+ if (len <= 0) {\r
+ throw new ApplicationException("Deflated stream ends early.");\r
+ }\r
+ inf.SetInput(buf, 0, len);\r
+ }\r
+ \r
+ /// <summary>\r
+ /// Reads one byte of decompressed data.\r
+ ///\r
+ /// The byte is baseInputStream the lower 8 bits of the int.\r
+ /// </summary>\r
+ public override int ReadByte()\r
+ {\r
+ int nread = Read(onebytebuffer, 0, 1); //read one byte\r
+ if (nread > 0) {\r
+ return onebytebuffer[0] & 0xff;\r
+ }\r
+ return -1; // ok\r
+ }\r
+ \r
+ /// <summary>\r
+ /// Decompresses data into the byte array\r
+ /// </summary>\r
+ /// <param name ="b">\r
+ /// the array to read and decompress data into\r
+ /// </param>\r
+ /// <param name ="off">\r
+ /// the offset indicating where the data should be placed\r
+ /// </param>\r
+ /// <param name ="len">\r
+ /// the number of bytes to decompress\r
+ /// </param>\r
+ public override int Read(byte[] b, int off, int len)\r
+ {\r
+ for (;;) {\r
+ int count;\r
+ try {\r
+ count = inf.Inflate(b, off, len);\r
+ } catch (Exception e) {\r
+ throw new ZipException(e.ToString());\r
+ }\r
+ \r
+ if (count > 0) {\r
+ return count;\r
+ }\r
+ \r
+ if (inf.IsNeedingDictionary) {\r
+ throw new ZipException("Need a dictionary");\r
+ } else if (inf.IsFinished) {\r
+ return 0;\r
+ } else if (inf.IsNeedingInput) {\r
+ Fill();\r
+ } else {\r
+ throw new InvalidOperationException("Don't know what to do");\r
+ }\r
+ }\r
+ }\r
+ \r
+ /// <summary>\r
+ /// Skip specified number of bytes of uncompressed data\r
+ /// </summary>\r
+ /// <param name ="n">\r
+ /// number of bytes to skip\r
+ /// </param>\r
+ public long Skip(long n)\r
+ {\r
+ if (n < 0) {\r
+ throw new ArgumentOutOfRangeException("n");\r
+ }\r
+ int len = 2048;\r
+ if (n < len) {\r
+ len = (int) n;\r
+ }\r
+ byte[] tmp = new byte[len];\r
+ return (long)baseInputStream.Read(tmp, 0, tmp.Length);\r
+ }\r
+ \r
+ #region Encryption stuff\r
+ protected byte[] cryptbuffer = null;\r
+ \r
+ uint[] keys = null;\r
+ protected byte DecryptByte()\r
+ {\r
+ uint temp = ((keys[2] & 0xFFFF) | 2);\r
+ return (byte)((temp * (temp ^ 1)) >> 8);\r
+ }\r
+ \r
+ protected void DecryptBlock(byte[] buf, int off, int len)\r
+ {\r
+ for (int i = off; i < off + len; ++i) {\r
+ buf[i] ^= DecryptByte();\r
+ UpdateKeys(buf[i]);\r
+ }\r
+ }\r
+ \r
+ protected void InitializePassword(string password)\r
+ {\r
+ keys = new uint[] {\r
+ 0x12345678,\r
+ 0x23456789,\r
+ 0x34567890\r
+ };\r
+ for (int i = 0; i < password.Length; ++i) {\r
+ UpdateKeys((byte)password[i]);\r
+ }\r
+ }\r
+ \r
+ protected void UpdateKeys(byte ch)\r
+ {\r
+ keys[0] = Crc32.ComputeCrc32(keys[0], ch);\r
+ keys[1] = keys[1] + (byte)keys[0];\r
+ keys[1] = keys[1] * 134775813 + 1;\r
+ keys[2] = Crc32.ComputeCrc32(keys[2], (byte)(keys[1] >> 24));\r
+ }\r
+ #endregion\r
+ }\r
+}\r
projects / reactos.git / blobdiff