"""
Original: https://github.com/antirez/redis/blob/3.2.6/src/crc64.c

/* Redis uses the CRC64 variant with "Jones" coefficients and init value of 0.
 *
 * Specification of this CRC64 variant follows:
 * Name: crc-64-jones
 * Width: 64 bites
 * Poly: 0xad93d23594c935a9
 * Reflected In: True
 * Xor_In: 0xffffffffffffffff
 * Reflected_Out: True
 * Xor_Out: 0x0
 * Check("123456789"): 0xe9c6d914c4b8d9ca
 *
 * Copyright (c) 2012, Salvatore Sanfilippo <antirez at gmail dot com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   * Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *   * Neither the name of Redis nor the names of its contributors may be used
 *     to endorse or promote products derived from this software without
 *     specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE. */

"""

import struct


UINT64_BITMASK = 2 ** 64 - 1
UINT8_BITMASK = 2 ** 8 - 1


def uint64_t(x):
    return x & UINT64_BITMASK


def uint8_t(x):
    return x & UINT8_BITMASK


UINT64_C = uint64_t


crc64_tab = [
    UINT64_C(0x0000000000000000), UINT64_C(0x7ad870c830358979),
    UINT64_C(0xf5b0e190606b12f2), UINT64_C(0x8f689158505e9b8b),
    UINT64_C(0xc038e5739841b68f), UINT64_C(0xbae095bba8743ff6),
    UINT64_C(0x358804e3f82aa47d), UINT64_C(0x4f50742bc81f2d04),
    UINT64_C(0xab28ecb46814fe75), UINT64_C(0xd1f09c7c5821770c),
    UINT64_C(0x5e980d24087fec87), UINT64_C(0x24407dec384a65fe),
    UINT64_C(0x6b1009c7f05548fa), UINT64_C(0x11c8790fc060c183),
    UINT64_C(0x9ea0e857903e5a08), UINT64_C(0xe478989fa00bd371),
    UINT64_C(0x7d08ff3b88be6f81), UINT64_C(0x07d08ff3b88be6f8),
    UINT64_C(0x88b81eabe8d57d73), UINT64_C(0xf2606e63d8e0f40a),
    UINT64_C(0xbd301a4810ffd90e), UINT64_C(0xc7e86a8020ca5077),
    UINT64_C(0x4880fbd87094cbfc), UINT64_C(0x32588b1040a14285),
    UINT64_C(0xd620138fe0aa91f4), UINT64_C(0xacf86347d09f188d),
    UINT64_C(0x2390f21f80c18306), UINT64_C(0x594882d7b0f40a7f),
    UINT64_C(0x1618f6fc78eb277b), UINT64_C(0x6cc0863448deae02),
    UINT64_C(0xe3a8176c18803589), UINT64_C(0x997067a428b5bcf0),
    UINT64_C(0xfa11fe77117cdf02), UINT64_C(0x80c98ebf2149567b),
    UINT64_C(0x0fa11fe77117cdf0), UINT64_C(0x75796f2f41224489),
    UINT64_C(0x3a291b04893d698d), UINT64_C(0x40f16bccb908e0f4),
    UINT64_C(0xcf99fa94e9567b7f), UINT64_C(0xb5418a5cd963f206),
    UINT64_C(0x513912c379682177), UINT64_C(0x2be1620b495da80e),
    UINT64_C(0xa489f35319033385), UINT64_C(0xde51839b2936bafc),
    UINT64_C(0x9101f7b0e12997f8), UINT64_C(0xebd98778d11c1e81),
    UINT64_C(0x64b116208142850a), UINT64_C(0x1e6966e8b1770c73),
    UINT64_C(0x8719014c99c2b083), UINT64_C(0xfdc17184a9f739fa),
    UINT64_C(0x72a9e0dcf9a9a271), UINT64_C(0x08719014c99c2b08),
    UINT64_C(0x4721e43f0183060c), UINT64_C(0x3df994f731b68f75),
    UINT64_C(0xb29105af61e814fe), UINT64_C(0xc849756751dd9d87),
    UINT64_C(0x2c31edf8f1d64ef6), UINT64_C(0x56e99d30c1e3c78f),
    UINT64_C(0xd9810c6891bd5c04), UINT64_C(0xa3597ca0a188d57d),
    UINT64_C(0xec09088b6997f879), UINT64_C(0x96d1784359a27100),
    UINT64_C(0x19b9e91b09fcea8b), UINT64_C(0x636199d339c963f2),
    UINT64_C(0xdf7adabd7a6e2d6f), UINT64_C(0xa5a2aa754a5ba416),
    UINT64_C(0x2aca3b2d1a053f9d), UINT64_C(0x50124be52a30b6e4),
    UINT64_C(0x1f423fcee22f9be0), UINT64_C(0x659a4f06d21a1299),
    UINT64_C(0xeaf2de5e82448912), UINT64_C(0x902aae96b271006b),
    UINT64_C(0x74523609127ad31a), UINT64_C(0x0e8a46c1224f5a63),
    UINT64_C(0x81e2d7997211c1e8), UINT64_C(0xfb3aa75142244891),
    UINT64_C(0xb46ad37a8a3b6595), UINT64_C(0xceb2a3b2ba0eecec),
    UINT64_C(0x41da32eaea507767), UINT64_C(0x3b024222da65fe1e),
    UINT64_C(0xa2722586f2d042ee), UINT64_C(0xd8aa554ec2e5cb97),
    UINT64_C(0x57c2c41692bb501c), UINT64_C(0x2d1ab4dea28ed965),
    UINT64_C(0x624ac0f56a91f461), UINT64_C(0x1892b03d5aa47d18),
    UINT64_C(0x97fa21650afae693), UINT64_C(0xed2251ad3acf6fea),
    UINT64_C(0x095ac9329ac4bc9b), UINT64_C(0x7382b9faaaf135e2),
    UINT64_C(0xfcea28a2faafae69), UINT64_C(0x8632586aca9a2710),
    UINT64_C(0xc9622c4102850a14), UINT64_C(0xb3ba5c8932b0836d),
    UINT64_C(0x3cd2cdd162ee18e6), UINT64_C(0x460abd1952db919f),
    UINT64_C(0x256b24ca6b12f26d), UINT64_C(0x5fb354025b277b14),
    UINT64_C(0xd0dbc55a0b79e09f), UINT64_C(0xaa03b5923b4c69e6),
    UINT64_C(0xe553c1b9f35344e2), UINT64_C(0x9f8bb171c366cd9b),
    UINT64_C(0x10e3202993385610), UINT64_C(0x6a3b50e1a30ddf69),
    UINT64_C(0x8e43c87e03060c18), UINT64_C(0xf49bb8b633338561),
    UINT64_C(0x7bf329ee636d1eea), UINT64_C(0x012b592653589793),
    UINT64_C(0x4e7b2d0d9b47ba97), UINT64_C(0x34a35dc5ab7233ee),
    UINT64_C(0xbbcbcc9dfb2ca865), UINT64_C(0xc113bc55cb19211c),
    UINT64_C(0x5863dbf1e3ac9dec), UINT64_C(0x22bbab39d3991495),
    UINT64_C(0xadd33a6183c78f1e), UINT64_C(0xd70b4aa9b3f20667),
    UINT64_C(0x985b3e827bed2b63), UINT64_C(0xe2834e4a4bd8a21a),
    UINT64_C(0x6debdf121b863991), UINT64_C(0x1733afda2bb3b0e8),
    UINT64_C(0xf34b37458bb86399), UINT64_C(0x8993478dbb8deae0),
    UINT64_C(0x06fbd6d5ebd3716b), UINT64_C(0x7c23a61ddbe6f812),
    UINT64_C(0x3373d23613f9d516), UINT64_C(0x49aba2fe23cc5c6f),
    UINT64_C(0xc6c333a67392c7e4), UINT64_C(0xbc1b436e43a74e9d),
    UINT64_C(0x95ac9329ac4bc9b5), UINT64_C(0xef74e3e19c7e40cc),
    UINT64_C(0x601c72b9cc20db47), UINT64_C(0x1ac40271fc15523e),
    UINT64_C(0x5594765a340a7f3a), UINT64_C(0x2f4c0692043ff643),
    UINT64_C(0xa02497ca54616dc8), UINT64_C(0xdafce7026454e4b1),
    UINT64_C(0x3e847f9dc45f37c0), UINT64_C(0x445c0f55f46abeb9),
    UINT64_C(0xcb349e0da4342532), UINT64_C(0xb1eceec59401ac4b),
    UINT64_C(0xfebc9aee5c1e814f), UINT64_C(0x8464ea266c2b0836),
    UINT64_C(0x0b0c7b7e3c7593bd), UINT64_C(0x71d40bb60c401ac4),
    UINT64_C(0xe8a46c1224f5a634), UINT64_C(0x927c1cda14c02f4d),
    UINT64_C(0x1d148d82449eb4c6), UINT64_C(0x67ccfd4a74ab3dbf),
    UINT64_C(0x289c8961bcb410bb), UINT64_C(0x5244f9a98c8199c2),
    UINT64_C(0xdd2c68f1dcdf0249), UINT64_C(0xa7f41839ecea8b30),
    UINT64_C(0x438c80a64ce15841), UINT64_C(0x3954f06e7cd4d138),
    UINT64_C(0xb63c61362c8a4ab3), UINT64_C(0xcce411fe1cbfc3ca),
    UINT64_C(0x83b465d5d4a0eece), UINT64_C(0xf96c151de49567b7),
    UINT64_C(0x76048445b4cbfc3c), UINT64_C(0x0cdcf48d84fe7545),
    UINT64_C(0x6fbd6d5ebd3716b7), UINT64_C(0x15651d968d029fce),
    UINT64_C(0x9a0d8ccedd5c0445), UINT64_C(0xe0d5fc06ed698d3c),
    UINT64_C(0xaf85882d2576a038), UINT64_C(0xd55df8e515432941),
    UINT64_C(0x5a3569bd451db2ca), UINT64_C(0x20ed197575283bb3),
    UINT64_C(0xc49581ead523e8c2), UINT64_C(0xbe4df122e51661bb),
    UINT64_C(0x3125607ab548fa30), UINT64_C(0x4bfd10b2857d7349),
    UINT64_C(0x04ad64994d625e4d), UINT64_C(0x7e7514517d57d734),
    UINT64_C(0xf11d85092d094cbf), UINT64_C(0x8bc5f5c11d3cc5c6),
    UINT64_C(0x12b5926535897936), UINT64_C(0x686de2ad05bcf04f),
    UINT64_C(0xe70573f555e26bc4), UINT64_C(0x9ddd033d65d7e2bd),
    UINT64_C(0xd28d7716adc8cfb9), UINT64_C(0xa85507de9dfd46c0),
    UINT64_C(0x273d9686cda3dd4b), UINT64_C(0x5de5e64efd965432),
    UINT64_C(0xb99d7ed15d9d8743), UINT64_C(0xc3450e196da80e3a),
    UINT64_C(0x4c2d9f413df695b1), UINT64_C(0x36f5ef890dc31cc8),
    UINT64_C(0x79a59ba2c5dc31cc), UINT64_C(0x037deb6af5e9b8b5),
    UINT64_C(0x8c157a32a5b7233e), UINT64_C(0xf6cd0afa9582aa47),
    UINT64_C(0x4ad64994d625e4da), UINT64_C(0x300e395ce6106da3),
    UINT64_C(0xbf66a804b64ef628), UINT64_C(0xc5bed8cc867b7f51),
    UINT64_C(0x8aeeace74e645255), UINT64_C(0xf036dc2f7e51db2c),
    UINT64_C(0x7f5e4d772e0f40a7), UINT64_C(0x05863dbf1e3ac9de),
    UINT64_C(0xe1fea520be311aaf), UINT64_C(0x9b26d5e88e0493d6),
    UINT64_C(0x144e44b0de5a085d), UINT64_C(0x6e963478ee6f8124),
    UINT64_C(0x21c640532670ac20), UINT64_C(0x5b1e309b16452559),
    UINT64_C(0xd476a1c3461bbed2), UINT64_C(0xaeaed10b762e37ab),
    UINT64_C(0x37deb6af5e9b8b5b), UINT64_C(0x4d06c6676eae0222),
    UINT64_C(0xc26e573f3ef099a9), UINT64_C(0xb8b627f70ec510d0),
    UINT64_C(0xf7e653dcc6da3dd4), UINT64_C(0x8d3e2314f6efb4ad),
    UINT64_C(0x0256b24ca6b12f26), UINT64_C(0x788ec2849684a65f),
    UINT64_C(0x9cf65a1b368f752e), UINT64_C(0xe62e2ad306bafc57),
    UINT64_C(0x6946bb8b56e467dc), UINT64_C(0x139ecb4366d1eea5),
    UINT64_C(0x5ccebf68aecec3a1), UINT64_C(0x2616cfa09efb4ad8),
    UINT64_C(0xa97e5ef8cea5d153), UINT64_C(0xd3a62e30fe90582a),
    UINT64_C(0xb0c7b7e3c7593bd8), UINT64_C(0xca1fc72bf76cb2a1),
    UINT64_C(0x45775673a732292a), UINT64_C(0x3faf26bb9707a053),
    UINT64_C(0x70ff52905f188d57), UINT64_C(0x0a2722586f2d042e),
    UINT64_C(0x854fb3003f739fa5), UINT64_C(0xff97c3c80f4616dc),
    UINT64_C(0x1bef5b57af4dc5ad), UINT64_C(0x61372b9f9f784cd4),
    UINT64_C(0xee5fbac7cf26d75f), UINT64_C(0x9487ca0fff135e26),
    UINT64_C(0xdbd7be24370c7322), UINT64_C(0xa10fceec0739fa5b),
    UINT64_C(0x2e675fb4576761d0), UINT64_C(0x54bf2f7c6752e8a9),
    UINT64_C(0xcdcf48d84fe75459), UINT64_C(0xb71738107fd2dd20),
    UINT64_C(0x387fa9482f8c46ab), UINT64_C(0x42a7d9801fb9cfd2),
    UINT64_C(0x0df7adabd7a6e2d6), UINT64_C(0x772fdd63e7936baf),
    UINT64_C(0xf8474c3bb7cdf024), UINT64_C(0x829f3cf387f8795d),
    UINT64_C(0x66e7a46c27f3aa2c), UINT64_C(0x1c3fd4a417c62355),
    UINT64_C(0x935745fc4798b8de), UINT64_C(0xe98f353477ad31a7),
    UINT64_C(0xa6df411fbfb21ca3), UINT64_C(0xdc0731d78f8795da),
    UINT64_C(0x536fa08fdfd90e51), UINT64_C(0x29b7d047efec8728),
]


def crc64(crc, bytes_):
    for byte in bytes_:
        crc = uint64_t(crc64_tab[uint8_t(crc) ^ byte] ^ (crc >> 8))
    return crc


def checksum(payload):
    return struct.pack('<Q', crc64(0, bytearray(payload)))
