Redis rdb文件CRC64校验算法 Java实现

查看RDB文件结构，发现最后的8字节是CRC64校验算得，从文件头开始直到8字节校验码前的FF结束码(含)，经过CRC64校验计算发现，貌似最后的8字节是小端模式实现的。

参考redis的crc64实现的代码，点击查看

Java代码如下：

 package com.jadic.utils;

 /**
  * @author     Jadic
  * @created 2014-5-15
  */
 public class CRC64 {
     private static final long[] LOOKUPTABLE = {
          0x0000000000000000L, 0x7ad870c830358979L, 0xf5b0e190606b12f2L, 0x8f689158505e9b8bL,
          0xc038e5739841b68fL, 0xbae095bba8743ff6L, 0x358804e3f82aa47dL, 0x4f50742bc81f2d04L,
          0xab28ecb46814fe75L, 0xd1f09c7c5821770cL, 0x5e980d24087fec87L, 0x24407dec384a65feL,
          0x6b1009c7f05548faL, 0x11c8790fc060c183L, 0x9ea0e857903e5a08L, 0xe478989fa00bd371L,
          0x7d08ff3b88be6f81L, 0x07d08ff3b88be6f8L, 0x88b81eabe8d57d73L, 0xf2606e63d8e0f40aL,
          0xbd301a4810ffd90eL, 0xc7e86a8020ca5077L, 0x4880fbd87094cbfcL, 0x32588b1040a14285L,
          0xd620138fe0aa91f4L, 0xacf86347d09f188dL, 0x2390f21f80c18306L, 0x594882d7b0f40a7fL,
          0x1618f6fc78eb277bL, 0x6cc0863448deae02L, 0xe3a8176c18803589L, 0x997067a428b5bcf0L,
          0xfa11fe77117cdf02L, 0x80c98ebf2149567bL, 0x0fa11fe77117cdf0L, 0x75796f2f41224489L,
          0x3a291b04893d698dL, 0x40f16bccb908e0f4L, 0xcf99fa94e9567b7fL, 0xb5418a5cd963f206L,
          0x513912c379682177L, 0x2be1620b495da80eL, 0xa489f35319033385L, 0xde51839b2936bafcL,
          0x9101f7b0e12997f8L, 0xebd98778d11c1e81L, 0x64b116208142850aL, 0x1e6966e8b1770c73L,
          0x8719014c99c2b083L, 0xfdc17184a9f739faL, 0x72a9e0dcf9a9a271L, 0x08719014c99c2b08L,
          0x4721e43f0183060cL, 0x3df994f731b68f75L, 0xb29105af61e814feL, 0xc849756751dd9d87L,
          0x2c31edf8f1d64ef6L, 0x56e99d30c1e3c78fL, 0xd9810c6891bd5c04L, 0xa3597ca0a188d57dL,
          0xec09088b6997f879L, 0x96d1784359a27100L, 0x19b9e91b09fcea8bL, 0x636199d339c963f2L,
          0xdf7adabd7a6e2d6fL, 0xa5a2aa754a5ba416L, 0x2aca3b2d1a053f9dL, 0x50124be52a30b6e4L,
          0x1f423fcee22f9be0L, 0x659a4f06d21a1299L, 0xeaf2de5e82448912L, 0x902aae96b271006bL,
          0x74523609127ad31aL, 0x0e8a46c1224f5a63L, 0x81e2d7997211c1e8L, 0xfb3aa75142244891L,
          0xb46ad37a8a3b6595L, 0xceb2a3b2ba0eececL, 0x41da32eaea507767L, 0x3b024222da65fe1eL,
          0xa2722586f2d042eeL, 0xd8aa554ec2e5cb97L, 0x57c2c41692bb501cL, 0x2d1ab4dea28ed965L,
          0x624ac0f56a91f461L, 0x1892b03d5aa47d18L, 0x97fa21650afae693L, 0xed2251ad3acf6feaL,
          0x095ac9329ac4bc9bL, 0x7382b9faaaf135e2L, 0xfcea28a2faafae69L, 0x8632586aca9a2710L,
          0xc9622c4102850a14L, 0xb3ba5c8932b0836dL, 0x3cd2cdd162ee18e6L, 0x460abd1952db919fL,
          0x256b24ca6b12f26dL, 0x5fb354025b277b14L, 0xd0dbc55a0b79e09fL, 0xaa03b5923b4c69e6L,
          0xe553c1b9f35344e2L, 0x9f8bb171c366cd9bL, 0x10e3202993385610L, 0x6a3b50e1a30ddf69L,
          0x8e43c87e03060c18L, 0xf49bb8b633338561L, 0x7bf329ee636d1eeaL, 0x012b592653589793L,
          0x4e7b2d0d9b47ba97L, 0x34a35dc5ab7233eeL, 0xbbcbcc9dfb2ca865L, 0xc113bc55cb19211cL,
          0x5863dbf1e3ac9decL, 0x22bbab39d3991495L, 0xadd33a6183c78f1eL, 0xd70b4aa9b3f20667L,
          0x985b3e827bed2b63L, 0xe2834e4a4bd8a21aL, 0x6debdf121b863991L, 0x1733afda2bb3b0e8L,
          0xf34b37458bb86399L, 0x8993478dbb8deae0L, 0x06fbd6d5ebd3716bL, 0x7c23a61ddbe6f812L,
          0x3373d23613f9d516L, 0x49aba2fe23cc5c6fL, 0xc6c333a67392c7e4L, 0xbc1b436e43a74e9dL,
          0x95ac9329ac4bc9b5L, 0xef74e3e19c7e40ccL, 0x601c72b9cc20db47L, 0x1ac40271fc15523eL,
          0x5594765a340a7f3aL, 0x2f4c0692043ff643L, 0xa02497ca54616dc8L, 0xdafce7026454e4b1L,
          0x3e847f9dc45f37c0L, 0x445c0f55f46abeb9L, 0xcb349e0da4342532L, 0xb1eceec59401ac4bL,
          0xfebc9aee5c1e814fL, 0x8464ea266c2b0836L, 0x0b0c7b7e3c7593bdL, 0x71d40bb60c401ac4L,
          0xe8a46c1224f5a634L, 0x927c1cda14c02f4dL, 0x1d148d82449eb4c6L, 0x67ccfd4a74ab3dbfL,
          0x289c8961bcb410bbL, 0x5244f9a98c8199c2L, 0xdd2c68f1dcdf0249L, 0xa7f41839ecea8b30L,
          0x438c80a64ce15841L, 0x3954f06e7cd4d138L, 0xb63c61362c8a4ab3L, 0xcce411fe1cbfc3caL,
          0x83b465d5d4a0eeceL, 0xf96c151de49567b7L, 0x76048445b4cbfc3cL, 0x0cdcf48d84fe7545L,
          0x6fbd6d5ebd3716b7L, 0x15651d968d029fceL, 0x9a0d8ccedd5c0445L, 0xe0d5fc06ed698d3cL,
          0xaf85882d2576a038L, 0xd55df8e515432941L, 0x5a3569bd451db2caL, 0x20ed197575283bb3L,
          0xc49581ead523e8c2L, 0xbe4df122e51661bbL, 0x3125607ab548fa30L, 0x4bfd10b2857d7349L,
          0x04ad64994d625e4dL, 0x7e7514517d57d734L, 0xf11d85092d094cbfL, 0x8bc5f5c11d3cc5c6L,
          0x12b5926535897936L, 0x686de2ad05bcf04fL, 0xe70573f555e26bc4L, 0x9ddd033d65d7e2bdL,
          0xd28d7716adc8cfb9L, 0xa85507de9dfd46c0L, 0x273d9686cda3dd4bL, 0x5de5e64efd965432L,
          0xb99d7ed15d9d8743L, 0xc3450e196da80e3aL, 0x4c2d9f413df695b1L, 0x36f5ef890dc31cc8L,
          0x79a59ba2c5dc31ccL, 0x037deb6af5e9b8b5L, 0x8c157a32a5b7233eL, 0xf6cd0afa9582aa47L,
          0x4ad64994d625e4daL, 0x300e395ce6106da3L, 0xbf66a804b64ef628L, 0xc5bed8cc867b7f51L,
          0x8aeeace74e645255L, 0xf036dc2f7e51db2cL, 0x7f5e4d772e0f40a7L, 0x05863dbf1e3ac9deL,
          0xe1fea520be311aafL, 0x9b26d5e88e0493d6L, 0x144e44b0de5a085dL, 0x6e963478ee6f8124L,
          0x21c640532670ac20L, 0x5b1e309b16452559L, 0xd476a1c3461bbed2L, 0xaeaed10b762e37abL,
          0x37deb6af5e9b8b5bL, 0x4d06c6676eae0222L, 0xc26e573f3ef099a9L, 0xb8b627f70ec510d0L,
          0xf7e653dcc6da3dd4L, 0x8d3e2314f6efb4adL, 0x0256b24ca6b12f26L, 0x788ec2849684a65fL,
          0x9cf65a1b368f752eL, 0xe62e2ad306bafc57L, 0x6946bb8b56e467dcL, 0x139ecb4366d1eea5L,
          0x5ccebf68aecec3a1L, 0x2616cfa09efb4ad8L, 0xa97e5ef8cea5d153L, 0xd3a62e30fe90582aL,
          0xb0c7b7e3c7593bd8L, 0xca1fc72bf76cb2a1L, 0x45775673a732292aL, 0x3faf26bb9707a053L,
          0x70ff52905f188d57L, 0x0a2722586f2d042eL, 0x854fb3003f739fa5L, 0xff97c3c80f4616dcL,
          0x1bef5b57af4dc5adL, 0x61372b9f9f784cd4L, 0xee5fbac7cf26d75fL, 0x9487ca0fff135e26L,
          0xdbd7be24370c7322L, 0xa10fceec0739fa5bL, 0x2e675fb4576761d0L, 0x54bf2f7c6752e8a9L,
          0xcdcf48d84fe75459L, 0xb71738107fd2dd20L, 0x387fa9482f8c46abL, 0x42a7d9801fb9cfd2L,
          0x0df7adabd7a6e2d6L, 0x772fdd63e7936bafL, 0xf8474c3bb7cdf024L, 0x829f3cf387f8795dL,
          0x66e7a46c27f3aa2cL, 0x1c3fd4a417c62355L, 0x935745fc4798b8deL, 0xe98f353477ad31a7L,
          0xa6df411fbfb21ca3L, 0xdc0731d78f8795daL, 0x536fa08fdfd90e51L, 0x29b7d047efec8728L
     };

     public static long digest(final byte[] data) {
         long checksum = 0;

         for (int i = 0; i < data.length; i++) {
             final int lookupidx = ((byte) checksum ^ data[i]) & 0xff;
             checksum = (checksum >>> 8) ^ LOOKUPTABLE[lookupidx];
         }

         return checksum;
     }
 }