mirror of
https://github.com/crskycode/GARbro.git
synced 2026-07-08 01:30:18 +08:00
moved checksum classes to separate file.
This commit is contained in:
morkt
@@ -23,7 +23,6 @@
|
||||
// IN THE SOFTWARE.
|
||||
//
|
||||
|
||||
using System.IO;
|
||||
using System.Text;
|
||||
|
||||
namespace GameRes.Utility
|
||||
@@ -230,274 +229,6 @@ namespace GameRes.Utility
|
||||
}
|
||||
}
|
||||
|
||||
public interface ICheckSum
|
||||
{
|
||||
uint Value { get; }
|
||||
void Update (byte[] buf, int pos, int len);
|
||||
}
|
||||
|
||||
public sealed class Crc32 : ICheckSum
|
||||
{
|
||||
/* Table of CRCs of all 8-bit messages. */
|
||||
private static readonly uint[] crc_table = InitializeTable();
|
||||
|
||||
public static uint[] Table { get { return crc_table; } }
|
||||
|
||||
/* Make the table for a fast CRC. */
|
||||
private static uint[] InitializeTable ()
|
||||
{
|
||||
uint[] table = new uint[256];
|
||||
for (uint n = 0; n < 256; n++)
|
||||
{
|
||||
uint c = n;
|
||||
for (int k = 0; k < 8; k++)
|
||||
{
|
||||
if (0 != (c & 1))
|
||||
c = 0xedb88320 ^ (c >> 1);
|
||||
else
|
||||
c = c >> 1;
|
||||
}
|
||||
table[n] = c;
|
||||
}
|
||||
return table;
|
||||
}
|
||||
|
||||
/* Update a running CRC with the bytes buf[0..len-1]--the CRC
|
||||
should be initialized to all 1's, and the transmitted value
|
||||
is the 1's complement of the final running CRC (see the
|
||||
crc() routine below)). */
|
||||
public static uint UpdateCrc (uint crc, byte[] buf, int pos, int len)
|
||||
{
|
||||
uint c = crc;
|
||||
for (int n = 0; n < len; n++)
|
||||
c = crc_table[(c ^ buf[pos+n]) & 0xff] ^ (c >> 8);
|
||||
return c;
|
||||
}
|
||||
|
||||
/* Return the CRC of the bytes buf[0..len-1]. */
|
||||
public static uint Compute (byte[] buf, int pos, int len)
|
||||
{
|
||||
return UpdateCrc (0xffffffff, buf, pos, len) ^ 0xffffffff;
|
||||
}
|
||||
|
||||
private uint m_crc = 0xffffffff;
|
||||
public uint Value { get { return m_crc^0xffffffff; } }
|
||||
|
||||
public void Update (byte[] buf, int pos, int len)
|
||||
{
|
||||
m_crc = UpdateCrc (m_crc, buf, pos, len);
|
||||
}
|
||||
}
|
||||
|
||||
/* Adler32 implementation -- borrowed from the 'zlib' compression library.
|
||||
|
||||
Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler
|
||||
|
||||
This software is provided 'as-is', without any express or implied
|
||||
warranty. In no event will the authors be held liable for any damages
|
||||
arising from the use of this software.
|
||||
|
||||
Permission is granted to anyone to use this software for any purpose,
|
||||
including commercial applications, and to alter it and redistribute it
|
||||
freely, subject to the following restrictions:
|
||||
|
||||
1. The origin of this software must not be misrepresented; you must not
|
||||
claim that you wrote the original software. If you use this software
|
||||
in a product, an acknowledgment in the product documentation would be
|
||||
appreciated but is not required.
|
||||
2. Altered source versions must be plainly marked as such, and must not be
|
||||
misrepresented as being the original software.
|
||||
3. This notice may not be removed or altered from any source distribution.
|
||||
*/
|
||||
|
||||
public sealed class Adler32 : ICheckSum
|
||||
{
|
||||
const uint BASE = 65521; /* largest prime smaller than 65536 */
|
||||
const int NMAX = 5552;
|
||||
|
||||
public static uint Compute (byte[] buf, int pos, int len)
|
||||
{
|
||||
unsafe
|
||||
{
|
||||
fixed (byte* ptr = &buf[pos])
|
||||
{
|
||||
return Update (1, ptr, len);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
public unsafe static uint Compute (byte* buf, int len)
|
||||
{
|
||||
return Update (1, buf, len);
|
||||
}
|
||||
|
||||
private unsafe static uint Update (uint adler, byte* buf, int len)
|
||||
{
|
||||
/* split Adler-32 into component sums */
|
||||
uint sum2 = (adler >> 16) & 0xffff;
|
||||
adler &= 0xffff;
|
||||
|
||||
/* in case user likes doing a byte at a time, keep it fast */
|
||||
if (1 == len) {
|
||||
adler += *buf;
|
||||
if (adler >= BASE)
|
||||
adler -= BASE;
|
||||
sum2 += adler;
|
||||
if (sum2 >= BASE)
|
||||
sum2 -= BASE;
|
||||
return adler | (sum2 << 16);
|
||||
}
|
||||
|
||||
/* in case short lengths are provided, keep it somewhat fast */
|
||||
if (len < 16) {
|
||||
while (0 != len--) {
|
||||
adler += *buf++;
|
||||
sum2 += adler;
|
||||
}
|
||||
if (adler >= BASE)
|
||||
adler -= BASE;
|
||||
sum2 %= BASE; /* only added so many BASE's */
|
||||
return adler | (sum2 << 16);
|
||||
}
|
||||
|
||||
/* do length NMAX blocks -- requires just one modulo operation */
|
||||
while (len >= NMAX) {
|
||||
len -= NMAX;
|
||||
int n = NMAX / 16; /* NMAX is divisible by 16 */
|
||||
do {
|
||||
/* 16 sums unrolled */
|
||||
adler += buf[0]; sum2 += adler;
|
||||
adler += buf[1]; sum2 += adler;
|
||||
adler += buf[2]; sum2 += adler;
|
||||
adler += buf[3]; sum2 += adler;
|
||||
adler += buf[4]; sum2 += adler;
|
||||
adler += buf[5]; sum2 += adler;
|
||||
adler += buf[6]; sum2 += adler;
|
||||
adler += buf[7]; sum2 += adler;
|
||||
adler += buf[8]; sum2 += adler;
|
||||
adler += buf[9]; sum2 += adler;
|
||||
adler += buf[10]; sum2 += adler;
|
||||
adler += buf[11]; sum2 += adler;
|
||||
adler += buf[12]; sum2 += adler;
|
||||
adler += buf[13]; sum2 += adler;
|
||||
adler += buf[14]; sum2 += adler;
|
||||
adler += buf[15]; sum2 += adler;
|
||||
buf += 16;
|
||||
} while (0 != --n);
|
||||
adler %= BASE;
|
||||
sum2 %= BASE;
|
||||
}
|
||||
|
||||
/* do remaining bytes (less than NMAX, still just one modulo) */
|
||||
if (0 != len) { /* avoid modulos if none remaining */
|
||||
while (len >= 16) {
|
||||
len -= 16;
|
||||
adler += buf[0]; sum2 += adler;
|
||||
adler += buf[1]; sum2 += adler;
|
||||
adler += buf[2]; sum2 += adler;
|
||||
adler += buf[3]; sum2 += adler;
|
||||
adler += buf[4]; sum2 += adler;
|
||||
adler += buf[5]; sum2 += adler;
|
||||
adler += buf[6]; sum2 += adler;
|
||||
adler += buf[7]; sum2 += adler;
|
||||
adler += buf[8]; sum2 += adler;
|
||||
adler += buf[9]; sum2 += adler;
|
||||
adler += buf[10]; sum2 += adler;
|
||||
adler += buf[11]; sum2 += adler;
|
||||
adler += buf[12]; sum2 += adler;
|
||||
adler += buf[13]; sum2 += adler;
|
||||
adler += buf[14]; sum2 += adler;
|
||||
adler += buf[15]; sum2 += adler;
|
||||
buf += 16;
|
||||
}
|
||||
while (0 != len--) {
|
||||
adler += *buf++;
|
||||
sum2 += adler;
|
||||
}
|
||||
adler %= BASE;
|
||||
sum2 %= BASE;
|
||||
}
|
||||
|
||||
/* return recombined sums */
|
||||
return adler | (sum2 << 16);
|
||||
}
|
||||
|
||||
private uint m_adler = 1;
|
||||
public uint Value { get { return m_adler; } }
|
||||
|
||||
public void Update (byte[] buf, int pos, int len)
|
||||
{
|
||||
unsafe
|
||||
{
|
||||
fixed (byte* ptr = &buf[pos])
|
||||
{
|
||||
m_adler = Update (m_adler, ptr, len);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
public unsafe uint Update (byte* buf, int len)
|
||||
{
|
||||
m_adler = Update (m_adler, buf, len);
|
||||
return m_adler;
|
||||
}
|
||||
}
|
||||
|
||||
public class CheckedStream : Stream
|
||||
{
|
||||
Stream m_stream;
|
||||
ICheckSum m_checksum;
|
||||
|
||||
public override bool CanRead { get { return m_stream.CanRead; } }
|
||||
public override bool CanWrite { get { return m_stream.CanWrite; } }
|
||||
public override bool CanSeek { get { return m_stream.CanSeek; } }
|
||||
public override long Length { get { return m_stream.Length; } }
|
||||
|
||||
public Stream BaseStream { get { return m_stream; } }
|
||||
public uint CheckSumValue { get { return m_checksum.Value; } }
|
||||
|
||||
public CheckedStream (Stream stream, ICheckSum algorithm)
|
||||
{
|
||||
m_stream = stream;
|
||||
m_checksum = algorithm;
|
||||
}
|
||||
|
||||
public override int Read (byte[] buffer, int offset, int count)
|
||||
{
|
||||
int read = m_stream.Read (buffer, offset, count);
|
||||
if (read > 0)
|
||||
m_checksum.Update (buffer, offset, read);
|
||||
return read;
|
||||
}
|
||||
|
||||
public override void Write (byte[] buffer, int offset, int count)
|
||||
{
|
||||
m_stream.Write (buffer, offset, count);
|
||||
m_checksum.Update (buffer, offset, count);
|
||||
}
|
||||
|
||||
public override long Position
|
||||
{
|
||||
get { return m_stream.Position; }
|
||||
set { m_stream.Position = value; }
|
||||
}
|
||||
|
||||
public override void SetLength (long value)
|
||||
{
|
||||
m_stream.SetLength (value);
|
||||
}
|
||||
|
||||
public override long Seek (long offset, SeekOrigin origin)
|
||||
{
|
||||
return m_stream.Seek (offset, origin);
|
||||
}
|
||||
|
||||
public override void Flush ()
|
||||
{
|
||||
m_stream.Flush();
|
||||
}
|
||||
}
|
||||
|
||||
public class AsciiString
|
||||
{
|
||||
public byte[] Value { get; set; }
|
||||
|
||||
Reference in New Issue
Block a user