// Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

const List<int> _CRC32_TABLE = const [
  0x00000000,
  0x77073096,
  0xEE0E612C,
  0x990951BA,
  0x076DC419,
  0x706AF48F,
  0xE963A535,
  0x9E6495A3,
  0x0EDB8832,
  0x79DCB8A4,
  0xE0D5E91E,
  0x97D2D988,
  0x09B64C2B,
  0x7EB17CBD,
  0xE7B82D07,
  0x90BF1D91,
  0x1DB71064,
  0x6AB020F2,
  0xF3B97148,
  0x84BE41DE,
  0x1ADAD47D,
  0x6DDDE4EB,
  0xF4D4B551,
  0x83D385C7,
  0x136C9856,
  0x646BA8C0,
  0xFD62F97A,
  0x8A65C9EC,
  0x14015C4F,
  0x63066CD9,
  0xFA0F3D63,
  0x8D080DF5,
  0x3B6E20C8,
  0x4C69105E,
  0xD56041E4,
  0xA2677172,
  0x3C03E4D1,
  0x4B04D447,
  0xD20D85FD,
  0xA50AB56B,
  0x35B5A8FA,
  0x42B2986C,
  0xDBBBC9D6,
  0xACBCF940,
  0x32D86CE3,
  0x45DF5C75,
  0xDCD60DCF,
  0xABD13D59,
  0x26D930AC,
  0x51DE003A,
  0xC8D75180,
  0xBFD06116,
  0x21B4F4B5,
  0x56B3C423,
  0xCFBA9599,
  0xB8BDA50F,
  0x2802B89E,
  0x5F058808,
  0xC60CD9B2,
  0xB10BE924,
  0x2F6F7C87,
  0x58684C11,
  0xC1611DAB,
  0xB6662D3D,
  0x76DC4190,
  0x01DB7106,
  0x98D220BC,
  0xEFD5102A,
  0x71B18589,
  0x06B6B51F,
  0x9FBFE4A5,
  0xE8B8D433,
  0x7807C9A2,
  0x0F00F934,
  0x9609A88E,
  0xE10E9818,
  0x7F6A0DBB,
  0x086D3D2D,
  0x91646C97,
  0xE6635C01,
  0x6B6B51F4,
  0x1C6C6162,
  0x856530D8,
  0xF262004E,
  0x6C0695ED,
  0x1B01A57B,
  0x8208F4C1,
  0xF50FC457,
  0x65B0D9C6,
  0x12B7E950,
  0x8BBEB8EA,
  0xFCB9887C,
  0x62DD1DDF,
  0x15DA2D49,
  0x8CD37CF3,
  0xFBD44C65,
  0x4DB26158,
  0x3AB551CE,
  0xA3BC0074,
  0xD4BB30E2,
  0x4ADFA541,
  0x3DD895D7,
  0xA4D1C46D,
  0xD3D6F4FB,
  0x4369E96A,
  0x346ED9FC,
  0xAD678846,
  0xDA60B8D0,
  0x44042D73,
  0x33031DE5,
  0xAA0A4C5F,
  0xDD0D7CC9,
  0x5005713C,
  0x270241AA,
  0xBE0B1010,
  0xC90C2086,
  0x5768B525,
  0x206F85B3,
  0xB966D409,
  0xCE61E49F,
  0x5EDEF90E,
  0x29D9C998,
  0xB0D09822,
  0xC7D7A8B4,
  0x59B33D17,
  0x2EB40D81,
  0xB7BD5C3B,
  0xC0BA6CAD,
  0xEDB88320,
  0x9ABFB3B6,
  0x03B6E20C,
  0x74B1D29A,
  0xEAD54739,
  0x9DD277AF,
  0x04DB2615,
  0x73DC1683,
  0xE3630B12,
  0x94643B84,
  0x0D6D6A3E,
  0x7A6A5AA8,
  0xE40ECF0B,
  0x9309FF9D,
  0x0A00AE27,
  0x7D079EB1,
  0xF00F9344,
  0x8708A3D2,
  0x1E01F268,
  0x6906C2FE,
  0xF762575D,
  0x806567CB,
  0x196C3671,
  0x6E6B06E7,
  0xFED41B76,
  0x89D32BE0,
  0x10DA7A5A,
  0x67DD4ACC,
  0xF9B9DF6F,
  0x8EBEEFF9,
  0x17B7BE43,
  0x60B08ED5,
  0xD6D6A3E8,
  0xA1D1937E,
  0x38D8C2C4,
  0x4FDFF252,
  0xD1BB67F1,
  0xA6BC5767,
  0x3FB506DD,
  0x48B2364B,
  0xD80D2BDA,
  0xAF0A1B4C,
  0x36034AF6,
  0x41047A60,
  0xDF60EFC3,
  0xA867DF55,
  0x316E8EEF,
  0x4669BE79,
  0xCB61B38C,
  0xBC66831A,
  0x256FD2A0,
  0x5268E236,
  0xCC0C7795,
  0xBB0B4703,
  0x220216B9,
  0x5505262F,
  0xC5BA3BBE,
  0xB2BD0B28,
  0x2BB45A92,
  0x5CB36A04,
  0xC2D7FFA7,
  0xB5D0CF31,
  0x2CD99E8B,
  0x5BDEAE1D,
  0x9B64C2B0,
  0xEC63F226,
  0x756AA39C,
  0x026D930A,
  0x9C0906A9,
  0xEB0E363F,
  0x72076785,
  0x05005713,
  0x95BF4A82,
  0xE2B87A14,
  0x7BB12BAE,
  0x0CB61B38,
  0x92D28E9B,
  0xE5D5BE0D,
  0x7CDCEFB7,
  0x0BDBDF21,
  0x86D3D2D4,
  0xF1D4E242,
  0x68DDB3F8,
  0x1FDA836E,
  0x81BE16CD,
  0xF6B9265B,
  0x6FB077E1,
  0x18B74777,
  0x88085AE6,
  0xFF0F6A70,
  0x66063BCA,
  0x11010B5C,
  0x8F659EFF,
  0xF862AE69,
  0x616BFFD3,
  0x166CCF45,
  0xA00AE278,
  0xD70DD2EE,
  0x4E048354,
  0x3903B3C2,
  0xA7672661,
  0xD06016F7,
  0x4969474D,
  0x3E6E77DB,
  0xAED16A4A,
  0xD9D65ADC,
  0x40DF0B66,
  0x37D83BF0,
  0xA9BCAE53,
  0xDEBB9EC5,
  0x47B2CF7F,
  0x30B5FFE9,
  0xBDBDF21C,
  0xCABAC28A,
  0x53B39330,
  0x24B4A3A6,
  0xBAD03605,
  0xCDD70693,
  0x54DE5729,
  0x23D967BF,
  0xB3667A2E,
  0xC4614AB8,
  0x5D681B02,
  0x2A6F2B94,
  0xB40BBE37,
  0xC30C8EA1,
  0x5A05DF1B,
  0x2D02EF8D
];

/**
 * Get the CRC-32 checksum of the given array. You can append bytes to an
 * already computed crc by specifying the previous [crc] value.
 */
int getCrc32(List<int> array, [int crc = 0]) {
  int len = array.length;
  crc = crc ^ 0xffffffff;
  int ip = 0;
  while (len >= 8) {
    crc = _CRC32_TABLE[(crc ^ array[ip++]) & 0xff] ^ (crc >> 8);
    crc = _CRC32_TABLE[(crc ^ array[ip++]) & 0xff] ^ (crc >> 8);
    crc = _CRC32_TABLE[(crc ^ array[ip++]) & 0xff] ^ (crc >> 8);
    crc = _CRC32_TABLE[(crc ^ array[ip++]) & 0xff] ^ (crc >> 8);
    crc = _CRC32_TABLE[(crc ^ array[ip++]) & 0xff] ^ (crc >> 8);
    crc = _CRC32_TABLE[(crc ^ array[ip++]) & 0xff] ^ (crc >> 8);
    crc = _CRC32_TABLE[(crc ^ array[ip++]) & 0xff] ^ (crc >> 8);
    crc = _CRC32_TABLE[(crc ^ array[ip++]) & 0xff] ^ (crc >> 8);
    len -= 8;
  }
  if (len > 0)
    do {
      crc = _CRC32_TABLE[(crc ^ array[ip++]) & 0xff] ^ (crc >> 8);
    } while (--len > 0);
  return crc ^ 0xffffffff;
}