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Diffstat (limited to 'src/crc64.c')
| -rw-r--r-- | src/crc64.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/src/crc64.c b/src/crc64.c new file mode 100644 index 0000000..73e0391 --- /dev/null +++ b/src/crc64.c @@ -0,0 +1,161 @@ +/* Copyright (c) 2014, Matt Stancliff <matt@genges.com> + * Copyright (c) 2020, Amazon Web Services + * 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. */ + +#include "crc64.h" +#include "crcspeed.h" +static uint64_t crc64_table[8][256] = {{0}}; + +#define POLY UINT64_C(0xad93d23594c935a9) +/******************** BEGIN GENERATED PYCRC FUNCTIONS ********************/ +/** + * Generated on Sun Dec 21 14:14:07 2014, + * by pycrc v0.8.2, https://www.tty1.net/pycrc/ + * + * LICENSE ON GENERATED CODE: + * ========================== + * As of version 0.6, pycrc is released under the terms of the MIT licence. + * The code generated by pycrc is not considered a substantial portion of the + * software, therefore the author of pycrc will not claim any copyright on + * the generated code. + * ========================== + * + * CRC configuration: + * Width = 64 + * Poly = 0xad93d23594c935a9 + * XorIn = 0xffffffffffffffff + * ReflectIn = True + * XorOut = 0x0000000000000000 + * ReflectOut = True + * Algorithm = bit-by-bit-fast + * + * Modifications after generation (by matt): + * - included finalize step in-line with update for single-call generation + * - re-worked some inner variable architectures + * - adjusted function parameters to match expected prototypes. + *****************************************************************************/ + +/** + * Reflect all bits of a \a data word of \a data_len bytes. + * + * \param data The data word to be reflected. + * \param data_len The width of \a data expressed in number of bits. + * \return The reflected data. + *****************************************************************************/ +static inline uint_fast64_t crc_reflect(uint_fast64_t data, size_t data_len) { + uint_fast64_t ret = data & 0x01; + + for (size_t i = 1; i < data_len; i++) { + data >>= 1; + ret = (ret << 1) | (data & 0x01); + } + + return ret; +} + +/** + * Update the crc value with new data. + * + * \param crc The current crc value. + * \param data Pointer to a buffer of \a data_len bytes. + * \param data_len Number of bytes in the \a data buffer. + * \return The updated crc value. + ******************************************************************************/ +uint64_t _crc64(uint_fast64_t crc, const void *in_data, const uint64_t len) { + const uint8_t *data = in_data; + unsigned long long bit; + + for (uint64_t offset = 0; offset < len; offset++) { + uint8_t c = data[offset]; + for (uint_fast8_t i = 0x01; i & 0xff; i <<= 1) { + bit = crc & 0x8000000000000000; + if (c & i) { + bit = !bit; + } + + crc <<= 1; + if (bit) { + crc ^= POLY; + } + } + + crc &= 0xffffffffffffffff; + } + + crc = crc & 0xffffffffffffffff; + return crc_reflect(crc, 64) ^ 0x0000000000000000; +} + +/******************** END GENERATED PYCRC FUNCTIONS ********************/ + +/* Initializes the 16KB lookup tables. */ +void crc64_init(void) { + crcspeed64native_init(_crc64, crc64_table); +} + +/* Compute crc64 */ +uint64_t crc64(uint64_t crc, const unsigned char *s, uint64_t l) { + return crcspeed64native(crc64_table, crc, (void *) s, l); +} + +/* Test main */ +#ifdef REDIS_TEST +#include <stdio.h> + +#define UNUSED(x) (void)(x) +int crc64Test(int argc, char *argv[], int flags) { + UNUSED(argc); + UNUSED(argv); + UNUSED(flags); + crc64_init(); + printf("[calcula]: e9c6d914c4b8d9ca == %016" PRIx64 "\n", + (uint64_t)_crc64(0, "123456789", 9)); + printf("[64speed]: e9c6d914c4b8d9ca == %016" PRIx64 "\n", + (uint64_t)crc64(0, (unsigned char*)"123456789", 9)); + char li[] = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed " + "do eiusmod tempor incididunt ut labore et dolore magna " + "aliqua. Ut enim ad minim veniam, quis nostrud exercitation " + "ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis " + "aute irure dolor in reprehenderit in voluptate velit esse " + "cillum dolore eu fugiat nulla pariatur. Excepteur sint " + "occaecat cupidatat non proident, sunt in culpa qui officia " + "deserunt mollit anim id est laborum."; + printf("[calcula]: c7794709e69683b3 == %016" PRIx64 "\n", + (uint64_t)_crc64(0, li, sizeof(li))); + printf("[64speed]: c7794709e69683b3 == %016" PRIx64 "\n", + (uint64_t)crc64(0, (unsigned char*)li, sizeof(li))); + return 0; +} + +#endif + +#ifdef REDIS_TEST_MAIN +int main(int argc, char *argv[]) { + return crc64Test(argc, argv); +} + +#endif |