using System;

namespace ICSharpCode.SharpZipLib.Checksums
{
	// Token: 0x0200000B RID: 11
	public sealed class Crc32 : IChecksum
	{
		// Token: 0x06000073 RID: 115 RVA: 0x00006226 File Offset: 0x00005226
		internal static uint ComputeCrc32(uint oldCrc, byte value)
		{
			return Crc32.CrcTable[(int)((UIntPtr)((oldCrc ^ (uint)value) & 255U))] ^ (oldCrc >> 8);
		}

		// Token: 0x17000010 RID: 16
		// (get) Token: 0x06000074 RID: 116 RVA: 0x0000623C File Offset: 0x0000523C
		// (set) Token: 0x06000075 RID: 117 RVA: 0x00006245 File Offset: 0x00005245
		public long Value
		{
			get
			{
				return (long)((ulong)this.crc);
			}
			set
			{
				this.crc = (uint)value;
			}
		}

		// Token: 0x06000076 RID: 118 RVA: 0x0000624F File Offset: 0x0000524F
		public void Reset()
		{
			this.crc = 0U;
		}

		// Token: 0x06000077 RID: 119 RVA: 0x00006258 File Offset: 0x00005258
		public void Update(int value)
		{
			this.crc ^= uint.MaxValue;
			checked
			{
				this.crc = Crc32.CrcTable[(int)((IntPtr)(unchecked((ulong)this.crc ^ (ulong)((long)value)) & 255UL))] ^ (this.crc >> 8);
				this.crc ^= uint.MaxValue;
			}
		}

		// Token: 0x06000078 RID: 120 RVA: 0x000062A8 File Offset: 0x000052A8
		public void Update(byte[] buffer)
		{
			if (buffer == null)
			{
				throw new ArgumentNullException("buffer");
			}
			this.Update(buffer, 0, buffer.Length);
		}

		// Token: 0x06000079 RID: 121 RVA: 0x000062C4 File Offset: 0x000052C4
		public void Update(byte[] buffer, int offset, int count)
		{
			if (buffer == null)
			{
				throw new ArgumentNullException("buffer");
			}
			if (count < 0)
			{
				throw new ArgumentOutOfRangeException("count", "Count cannot be less than zero");
			}
			if (offset < 0 || offset + count > buffer.Length)
			{
				throw new ArgumentOutOfRangeException("offset");
			}
			this.crc ^= uint.MaxValue;
			while (--count >= 0)
			{
				this.crc = Crc32.CrcTable[(int)((UIntPtr)((this.crc ^ (uint)buffer[offset++]) & 255U))] ^ (this.crc >> 8);
			}
			this.crc ^= uint.MaxValue;
		}

		// Token: 0x04000068 RID: 104
		private const uint CrcSeed = 4294967295U;

		// Token: 0x04000069 RID: 105
		private static readonly uint[] CrcTable = new uint[]
		{
			0U, 1996959894U, 3993919788U, 2567524794U, 124634137U, 1886057615U, 3915621685U, 2657392035U, 249268274U, 2044508324U,
			3772115230U, 2547177864U, 162941995U, 2125561021U, 3887607047U, 2428444049U, 498536548U, 1789927666U, 4089016648U, 2227061214U,
			450548861U, 1843258603U, 4107580753U, 2211677639U, 325883990U, 1684777152U, 4251122042U, 2321926636U, 335633487U, 1661365465U,
			4195302755U, 2366115317U, 997073096U, 1281953886U, 3579855332U, 2724688242U, 1006888145U, 1258607687U, 3524101629U, 2768942443U,
			901097722U, 1119000684U, 3686517206U, 2898065728U, 853044451U, 1172266101U, 3705015759U, 2882616665U, 651767980U, 1373503546U,
			3369554304U, 3218104598U, 565507253U, 1454621731U, 3485111705U, 3099436303U, 671266974U, 1594198024U, 3322730930U, 2970347812U,
			795835527U, 1483230225U, 3244367275U, 3060149565U, 1994146192U, 31158534U, 2563907772U, 4023717930U, 1907459465U, 112637215U,
			2680153253U, 3904427059U, 2013776290U, 251722036U, 2517215374U, 3775830040U, 2137656763U, 141376813U, 2439277719U, 3865271297U,
			1802195444U, 476864866U, 2238001368U, 4066508878U, 1812370925U, 453092731U, 2181625025U, 4111451223U, 1706088902U, 314042704U,
			2344532202U, 4240017532U, 1658658271U, 366619977U, 2362670323U, 4224994405U, 1303535960U, 984961486U, 2747007092U, 3569037538U,
			1256170817U, 1037604311U, 2765210733U, 3554079995U, 1131014506U, 879679996U, 2909243462U, 3663771856U, 1141124467U, 855842277U,
			2852801631U, 3708648649U, 1342533948U, 654459306U, 3188396048U, 3373015174U, 1466479909U, 544179635U, 3110523913U, 3462522015U,
			1591671054U, 702138776U, 2966460450U, 3352799412U, 1504918807U, 783551873U, 3082640443U, 3233442989U, 3988292384U, 2596254646U,
			62317068U, 1957810842U, 3939845945U, 2647816111U, 81470997U, 1943803523U, 3814918930U, 2489596804U, 225274430U, 2053790376U,
			3826175755U, 2466906013U, 167816743U, 2097651377U, 4027552580U, 2265490386U, 503444072U, 1762050814U, 4150417245U, 2154129355U,
			426522225U, 1852507879U, 4275313526U, 2312317920U, 282753626U, 1742555852U, 4189708143U, 2394877945U, 397917763U, 1622183637U,
			3604390888U, 2714866558U, 953729732U, 1340076626U, 3518719985U, 2797360999U, 1068828381U, 1219638859U, 3624741850U, 2936675148U,
			906185462U, 1090812512U, 3747672003U, 2825379669U, 829329135U, 1181335161U, 3412177804U, 3160834842U, 628085408U, 1382605366U,
			3423369109U, 3138078467U, 570562233U, 1426400815U, 3317316542U, 2998733608U, 733239954U, 1555261956U, 3268935591U, 3050360625U,
			752459403U, 1541320221U, 2607071920U, 3965973030U, 1969922972U, 40735498U, 2617837225U, 3943577151U, 1913087877U, 83908371U,
			2512341634U, 3803740692U, 2075208622U, 213261112U, 2463272603U, 3855990285U, 2094854071U, 198958881U, 2262029012U, 4057260610U,
			1759359992U, 534414190U, 2176718541U, 4139329115U, 1873836001U, 414664567U, 2282248934U, 4279200368U, 1711684554U, 285281116U,
			2405801727U, 4167216745U, 1634467795U, 376229701U, 2685067896U, 3608007406U, 1308918612U, 956543938U, 2808555105U, 3495958263U,
			1231636301U, 1047427035U, 2932959818U, 3654703836U, 1088359270U, 936918000U, 2847714899U, 3736837829U, 1202900863U, 817233897U,
			3183342108U, 3401237130U, 1404277552U, 615818150U, 3134207493U, 3453421203U, 1423857449U, 601450431U, 3009837614U, 3294710456U,
			1567103746U, 711928724U, 3020668471U, 3272380065U, 1510334235U, 755167117U
		};

		// Token: 0x0400006A RID: 106
		private uint crc;
	}
}