public static byte[] compress(byte[] source, int level)
{
int i = 0;
int num = 13;
uint num2 = 2147483648u;
int i2 = 9;
byte[] array = new byte[source.Length + 400];
int[] array2 = new int[4096];
byte[] array3 = new byte[4096];
int num3 = 0;
int num4 = source.Length - 6 - 4 - 1;
int num5 = 0;
if (level != 1 && level != 3)
{
throw new ArgumentException("C# version only supports level 1 and 3");
}
int[,] array4;
if (level == 1)
{
array4 = new int[4096, 1];
}
else
{
array4 = new int[4096, 16];
}
if (source.Length == 0)
{
return(new byte[0]);
}
if (i <= num4)
{
num3 = ((int)source[i] | (int)source[i + 1] << 8 | (int)source[i + 2] << 16);
}
byte[] array5;
while (i <= num4)
{
if ((num2 & 1u) == 1u)
{
if (i > source.Length >> 1 && num > i - (i >> 5))
{
array5 = new byte[source.Length + 9];
QuickLZ.write_header(array5, level, false, source.Length, source.Length + 9);
Array.Copy(source, 0, array5, 9, source.Length);
return(array5);
}
QuickLZ.fast_write(array, i2, (int)(num2 >> 1 | 2147483648u), 4);
i2 = num;
num += 4;
num2 = 2147483648u;
}
if (level == 1)
{
int num6 = (num3 >> 12 ^ num3) & 4095;
int num7 = array4[num6, 0];
int num8 = array2[num6] ^ num3;
array2[num6] = num3;
array4[num6, 0] = i;
if (num8 == 0 && array3[num6] != 0 && (i - num7 > 2 || (i == num7 + 1 && num5 >= 3 && i > 3 && source[i] == source[i - 3] && source[i] == source[i - 2] && source[i] == source[i - 1] && source[i] == source[i + 1] && source[i] == source[i + 2])))
{
num2 = (num2 >> 1 | 2147483648u);
if (source[num7 + 3] != source[i + 3])
{
int num9 = 1 | num6 << 4;
array[num] = (byte)num9;
array[num + 1] = (byte)(num9 >> 8);
i += 3;
num += 2;
}
else
{
int num10 = i;
int num11 = (source.Length - 4 - i + 1 - 1 <= 255) ? (source.Length - 4 - i + 1 - 1) : 255;
i += 4;
if (source[num7 + i - num10] == source[i])
{
i++;
if (source[num7 + i - num10] == source[i])
{
i++;
while (source[num7 + (i - num10)] == source[i] && i - num10 < num11)
{
i++;
}
}
}
int num12 = i - num10;
num6 <<= 4;
if (num12 < 18)
{
int num13 = num6 | num12 - 2;
array[num] = (byte)num13;
array[num + 1] = (byte)(num13 >> 8);
num += 2;
}
else
{
QuickLZ.fast_write(array, num, num6 | num12 << 16, 3);
num += 3;
}
}
num3 = ((int)source[i] | (int)source[i + 1] << 8 | (int)source[i + 2] << 16);
num5 = 0;
}
else
{
num5++;
array3[num6] = 1;
array[num] = source[i];
num2 >>= 1;
i++;
num++;
num3 = ((num3 >> 8 & 65535) | (int)source[i + 2] << 16);
}
}
else
{
num3 = ((int)source[i] | (int)source[i + 1] << 8 | (int)source[i + 2] << 16);
int num14 = (source.Length - 4 - i + 1 - 1 <= 255) ? (source.Length - 4 - i + 1 - 1) : 255;
int num15 = (num3 >> 12 ^ num3) & 4095;
byte b = array3[num15];
int num16 = 0;
int num17 = 0;
int num18 = 0;
int num19;
while (num18 < 16 && (int)b > num18)
{
num19 = array4[num15, num18];
if ((byte)num3 == source[num19] && (byte)(num3 >> 8) == source[num19 + 1] && (byte)(num3 >> 16) == source[num19 + 2] && num19 < i - 2)
{
int num20 = 3;
while (source[num19 + num20] == source[i + num20] && num20 < num14)
{
num20++;
}
if (num20 > num16 || (num20 == num16 && num19 > num17))
{
num17 = num19;
num16 = num20;
}
}
num18++;
}
num19 = num17;
array4[num15, (int)(b & 15)] = i;
b += 1;
array3[num15] = b;
if (num16 >= 3 && i - num19 < 131071)
{
int num21 = i - num19;
for (int j = 1; j < num16; j++)
{
num3 = ((int)source[i + j] | (int)source[i + j + 1] << 8 | (int)source[i + j + 2] << 16);
num15 = ((num3 >> 12 ^ num3) & 4095);
byte[] expr_4D5_cp_0 = array3;
int expr_4D5_cp_1 = num15;
byte b2;
expr_4D5_cp_0[expr_4D5_cp_1] = (b2 = expr_4D5_cp_0[expr_4D5_cp_1]) + 1;
b = b2;
array4[num15, (int)(b & 15)] = i + j;
}
i += num16;
num2 = (num2 >> 1 | 2147483648u);
if (num16 == 3 && num21 <= 63)
{
QuickLZ.fast_write(array, num, num21 << 2, 1);
num++;
}
else if (num16 == 3 && num21 <= 16383)
{
QuickLZ.fast_write(array, num, num21 << 2 | 1, 2);
num += 2;
}
else if (num16 <= 18 && num21 <= 1023)
{
QuickLZ.fast_write(array, num, num16 - 3 << 2 | num21 << 6 | 2, 2);
num += 2;
}
else if (num16 <= 33)
{
QuickLZ.fast_write(array, num, num16 - 2 << 2 | num21 << 7 | 3, 3);
num += 3;
}
else
{
QuickLZ.fast_write(array, num, num16 - 3 << 7 | num21 << 15 | 3, 4);
num += 4;
}
num5 = 0;
}
else
{
array[num] = source[i];
num2 >>= 1;
i++;
num++;
}
}
}
while (i <= source.Length - 1)
{
if ((num2 & 1u) == 1u)
{
QuickLZ.fast_write(array, i2, (int)(num2 >> 1 | 2147483648u), 4);
i2 = num;
num += 4;
num2 = 2147483648u;
}
array[num] = source[i];
i++;
num++;
num2 >>= 1;
}
while ((num2 & 1u) != 1u)
{
num2 >>= 1;
}
QuickLZ.fast_write(array, i2, (int)(num2 >> 1 | 2147483648u), 4);
QuickLZ.write_header(array, level, true, source.Length, num);
array5 = new byte[num];
Array.Copy(array, array5, num);
return(array5);
}