mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-12-04 21:42:39 +00:00
459 lines
14 KiB
C
459 lines
14 KiB
C
|
/* crc32.c -- compute the CRC-32 of a data stream
|
||
|
* Copyright (C) 1995-2006, 2010, 2011, 2012 Mark Adler
|
||
|
* For conditions of distribution and use, see copyright notice in zlib.h
|
||
|
*
|
||
|
* Thanks to Rodney Brown <rbrown64@csc.com.au> for his contribution of faster
|
||
|
* CRC methods: exclusive-oring 32 bits of data at a time, and pre-computing
|
||
|
* tables for updating the shift register in one step with three exclusive-ors
|
||
|
* instead of four steps with four exclusive-ors. This results in about a
|
||
|
* factor of two increase in speed on a Power PC G4 (PPC7455) using gcc -O3.
|
||
|
*/
|
||
|
|
||
|
/* @(#) $Id$ */
|
||
|
|
||
|
#ifdef __MINGW32__
|
||
|
# include <sys/param.h>
|
||
|
#elif defined(WIN32) || defined(_WIN32)
|
||
|
# define LITTLE_ENDIAN 1234
|
||
|
# define BIG_ENDIAN 4321
|
||
|
# if defined(_M_IX86) || defined(_M_AMD64) || defined(_M_IA64)
|
||
|
# define BYTE_ORDER LITTLE_ENDIAN
|
||
|
# else
|
||
|
# error Unknown endianness!
|
||
|
# endif
|
||
|
#elif __APPLE__
|
||
|
# include <machine/endian.h>
|
||
|
#elif defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__bsdi__) || defined(__DragonFly__)
|
||
|
# include <sys/endian.h>
|
||
|
#elif defined(__sun) || defined(sun)
|
||
|
# include <sys/byteorder.h>
|
||
|
# if !defined(LITTLE_ENDIAN)
|
||
|
# define LITTLE_ENDIAN 4321
|
||
|
# endif
|
||
|
# if !defined(BIG_ENDIAN)
|
||
|
# define BIG_ENDIAN 1234
|
||
|
# endif
|
||
|
# if !defined(BYTE_ORDER)
|
||
|
# if defined(_BIG_ENDIAN)
|
||
|
# define BYTE_ORDER BIG_ENDIAN
|
||
|
# else
|
||
|
# define BYTE_ORDER LITTLE_ENDIAN
|
||
|
# endif
|
||
|
# endif
|
||
|
#else
|
||
|
# include <endian.h>
|
||
|
#endif
|
||
|
|
||
|
/*
|
||
|
Note on the use of DYNAMIC_CRC_TABLE: there is no mutex or semaphore
|
||
|
protection on the static variables used to control the first-use generation
|
||
|
of the crc tables. Therefore, if you #define DYNAMIC_CRC_TABLE, you should
|
||
|
first call get_crc_table() to initialize the tables before allowing more than
|
||
|
one thread to use crc32().
|
||
|
|
||
|
DYNAMIC_CRC_TABLE and MAKECRCH can be #defined to write out crc32.h.
|
||
|
*/
|
||
|
|
||
|
#ifdef MAKECRCH
|
||
|
# include <stdio.h>
|
||
|
# ifndef DYNAMIC_CRC_TABLE
|
||
|
# define DYNAMIC_CRC_TABLE
|
||
|
# endif /* !DYNAMIC_CRC_TABLE */
|
||
|
#endif /* MAKECRCH */
|
||
|
|
||
|
#include "deflate.h"
|
||
|
|
||
|
#if BYTE_ORDER == LITTLE_ENDIAN
|
||
|
static uint32_t crc32_little(uint32_t, const unsigned char *, z_off64_t);
|
||
|
#elif BYTE_ORDER == BIG_ENDIAN
|
||
|
static uint32_t crc32_big(uint32_t, const unsigned char *, z_off64_t);
|
||
|
#endif
|
||
|
|
||
|
/* Local functions for crc concatenation */
|
||
|
static uint32_t gf2_matrix_times(uint32_t *mat, uint32_t vec);
|
||
|
static void gf2_matrix_square(uint32_t *square, uint32_t *mat);
|
||
|
static uint32_t crc32_combine_(uint32_t crc1, uint32_t crc2, z_off64_t len2);
|
||
|
|
||
|
|
||
|
#ifdef DYNAMIC_CRC_TABLE
|
||
|
static volatile int crc_table_empty = 1;
|
||
|
static uint32_t crc_table[8][256];
|
||
|
static void make_crc_table(void);
|
||
|
#ifdef MAKECRCH
|
||
|
static void write_table(FILE *, const uint32_t *);
|
||
|
#endif /* MAKECRCH */
|
||
|
/*
|
||
|
Generate tables for a byte-wise 32-bit CRC calculation on the polynomial:
|
||
|
x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x+1.
|
||
|
|
||
|
Polynomials over GF(2) are represented in binary, one bit per coefficient,
|
||
|
with the lowest powers in the most significant bit. Then adding polynomials
|
||
|
is just exclusive-or, and multiplying a polynomial by x is a right shift by
|
||
|
one. If we call the above polynomial p, and represent a byte as the
|
||
|
polynomial q, also with the lowest power in the most significant bit (so the
|
||
|
byte 0xb1 is the polynomial x^7+x^3+x+1), then the CRC is (q*x^32) mod p,
|
||
|
where a mod b means the remainder after dividing a by b.
|
||
|
|
||
|
This calculation is done using the shift-register method of multiplying and
|
||
|
taking the remainder. The register is initialized to zero, and for each
|
||
|
incoming bit, x^32 is added mod p to the register if the bit is a one (where
|
||
|
x^32 mod p is p+x^32 = x^26+...+1), and the register is multiplied mod p by
|
||
|
x (which is shifting right by one and adding x^32 mod p if the bit shifted
|
||
|
out is a one). We start with the highest power (least significant bit) of
|
||
|
q and repeat for all eight bits of q.
|
||
|
|
||
|
The first table is simply the CRC of all possible eight bit values. This is
|
||
|
all the information needed to generate CRCs on data a byte at a time for all
|
||
|
combinations of CRC register values and incoming bytes. The remaining tables
|
||
|
allow for word-at-a-time CRC calculation for both big-endian and little-
|
||
|
endian machines, where a word is four bytes.
|
||
|
*/
|
||
|
static void make_crc_table() {
|
||
|
uint32_t c;
|
||
|
int n, k;
|
||
|
uint32_t poly; /* polynomial exclusive-or pattern */
|
||
|
/* terms of polynomial defining this crc (except x^32): */
|
||
|
static volatile int first = 1; /* flag to limit concurrent making */
|
||
|
static const unsigned char p[] = {0, 1, 2, 4, 5, 7, 8, 10, 11, 12, 16, 22, 23, 26};
|
||
|
|
||
|
/* See if another task is already doing this (not thread-safe, but better
|
||
|
than nothing -- significantly reduces duration of vulnerability in
|
||
|
case the advice about DYNAMIC_CRC_TABLE is ignored) */
|
||
|
if (first) {
|
||
|
first = 0;
|
||
|
|
||
|
/* make exclusive-or pattern from polynomial (0xedb88320) */
|
||
|
poly = 0;
|
||
|
for (n = 0; n < (int)(sizeof(p)/sizeof(unsigned char)); n++)
|
||
|
poly |= (uint32_t)1 << (31 - p[n]);
|
||
|
|
||
|
/* generate a crc for every 8-bit value */
|
||
|
for (n = 0; n < 256; n++) {
|
||
|
c = (uint32_t)n;
|
||
|
for (k = 0; k < 8; k++)
|
||
|
c = c & 1 ? poly ^ (c >> 1) : c >> 1;
|
||
|
crc_table[0][n] = c;
|
||
|
}
|
||
|
|
||
|
/* generate crc for each value followed by one, two, and three zeros,
|
||
|
and then the byte reversal of those as well as the first table */
|
||
|
for (n = 0; n < 256; n++) {
|
||
|
c = crc_table[0][n];
|
||
|
crc_table[4][n] = ZSWAP32(c);
|
||
|
for (k = 1; k < 4; k++) {
|
||
|
c = crc_table[0][c & 0xff] ^ (c >> 8);
|
||
|
crc_table[k][n] = c;
|
||
|
crc_table[k + 4][n] = ZSWAP32(c);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
crc_table_empty = 0;
|
||
|
} else { /* not first */
|
||
|
/* wait for the other guy to finish (not efficient, but rare) */
|
||
|
while (crc_table_empty)
|
||
|
{}
|
||
|
}
|
||
|
|
||
|
#ifdef MAKECRCH
|
||
|
/* write out CRC tables to crc32.h */
|
||
|
{
|
||
|
FILE *out;
|
||
|
|
||
|
out = fopen("crc32.h", "w");
|
||
|
if (out == NULL) return;
|
||
|
fprintf(out, "/* crc32.h -- tables for rapid CRC calculation\n");
|
||
|
fprintf(out, " * Generated automatically by crc32.c\n */\n\n");
|
||
|
fprintf(out, "static const uint32_t ");
|
||
|
fprintf(out, "crc_table[8][256] =\n{\n {\n");
|
||
|
write_table(out, crc_table[0]);
|
||
|
for (k = 1; k < 8; k++) {
|
||
|
fprintf(out, " },\n {\n");
|
||
|
write_table(out, crc_table[k]);
|
||
|
}
|
||
|
fprintf(out, " }\n};\n");
|
||
|
fclose(out);
|
||
|
}
|
||
|
#endif /* MAKECRCH */
|
||
|
}
|
||
|
|
||
|
#ifdef MAKECRCH
|
||
|
static void write_table(FILE *out, const uint32_t *table) {
|
||
|
int n;
|
||
|
|
||
|
for (n = 0; n < 256; n++)
|
||
|
fprintf(out, "%s0x%08lx%s", n % 5 ? "" : " ",
|
||
|
(uint32_t)(table[n]),
|
||
|
n == 255 ? "\n" : (n % 5 == 4 ? ",\n" : ", "));
|
||
|
}
|
||
|
#endif /* MAKECRCH */
|
||
|
|
||
|
#else /* !DYNAMIC_CRC_TABLE */
|
||
|
/* ========================================================================
|
||
|
* Tables of CRC-32s of all single-byte values, made by make_crc_table().
|
||
|
*/
|
||
|
#include "crc32.h"
|
||
|
#endif /* DYNAMIC_CRC_TABLE */
|
||
|
|
||
|
/* =========================================================================
|
||
|
* This function can be used by asm versions of crc32()
|
||
|
*/
|
||
|
const uint32_t * ZEXPORT get_crc_table(void) {
|
||
|
#ifdef DYNAMIC_CRC_TABLE
|
||
|
if (crc_table_empty)
|
||
|
make_crc_table();
|
||
|
#endif /* DYNAMIC_CRC_TABLE */
|
||
|
return (const uint32_t *)crc_table;
|
||
|
}
|
||
|
|
||
|
/* ========================================================================= */
|
||
|
#define DO1 crc = crc_table[0][((int)crc ^ (*buf++)) & 0xff] ^ (crc >> 8)
|
||
|
#define DO8 DO1; DO1; DO1; DO1; DO1; DO1; DO1; DO1
|
||
|
#define DO4 DO1; DO1; DO1; DO1
|
||
|
|
||
|
/* ========================================================================= */
|
||
|
uint32_t ZEXPORT crc32(uint32_t crc, const unsigned char *buf, z_off64_t len) {
|
||
|
if (buf == Z_NULL) return 0;
|
||
|
|
||
|
#ifdef DYNAMIC_CRC_TABLE
|
||
|
if (crc_table_empty)
|
||
|
make_crc_table();
|
||
|
#endif /* DYNAMIC_CRC_TABLE */
|
||
|
|
||
|
if (sizeof(void *) == sizeof(ptrdiff_t)) {
|
||
|
#if BYTE_ORDER == LITTLE_ENDIAN
|
||
|
return crc32_little(crc, buf, len);
|
||
|
#elif BYTE_ORDER == BIG_ENDIAN
|
||
|
return crc32_big(crc, buf, len);
|
||
|
#endif
|
||
|
}
|
||
|
crc = crc ^ 0xffffffff;
|
||
|
|
||
|
#ifdef UNROLL_LESS
|
||
|
while (len >= 4) {
|
||
|
DO4;
|
||
|
len -= 4;
|
||
|
}
|
||
|
#else
|
||
|
while (len >= 8) {
|
||
|
DO8;
|
||
|
len -= 8;
|
||
|
}
|
||
|
#endif
|
||
|
|
||
|
if (len) do {
|
||
|
DO1;
|
||
|
} while (--len);
|
||
|
return crc ^ 0xffffffff;
|
||
|
}
|
||
|
|
||
|
|
||
|
/* ========================================================================= */
|
||
|
#if BYTE_ORDER == LITTLE_ENDIAN
|
||
|
#define DOLIT4 c ^= *buf4++; \
|
||
|
c = crc_table[3][c & 0xff] ^ crc_table[2][(c >> 8) & 0xff] ^ \
|
||
|
crc_table[1][(c >> 16) & 0xff] ^ crc_table[0][c >> 24]
|
||
|
#define DOLIT32 DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4
|
||
|
|
||
|
/* ========================================================================= */
|
||
|
static uint32_t crc32_little(uint32_t crc, const unsigned char *buf, z_off64_t len) {
|
||
|
register uint32_t c;
|
||
|
register const uint32_t *buf4;
|
||
|
|
||
|
c = crc;
|
||
|
c = ~c;
|
||
|
while (len && ((ptrdiff_t)buf & 3)) {
|
||
|
c = crc_table[0][(c ^ *buf++) & 0xff] ^ (c >> 8);
|
||
|
len--;
|
||
|
}
|
||
|
|
||
|
buf4 = (const uint32_t *)(const void *)buf;
|
||
|
|
||
|
#ifndef UNROLL_LESS
|
||
|
while (len >= 32) {
|
||
|
DOLIT32;
|
||
|
len -= 32;
|
||
|
}
|
||
|
#endif
|
||
|
|
||
|
while (len >= 4) {
|
||
|
DOLIT4;
|
||
|
len -= 4;
|
||
|
}
|
||
|
buf = (const unsigned char *)buf4;
|
||
|
|
||
|
if (len) do {
|
||
|
c = crc_table[0][(c ^ *buf++) & 0xff] ^ (c >> 8);
|
||
|
} while (--len);
|
||
|
c = ~c;
|
||
|
return c;
|
||
|
}
|
||
|
#endif /* BYTE_ORDER == LITTLE_ENDIAN */
|
||
|
|
||
|
/* ========================================================================= */
|
||
|
#if BYTE_ORDER == BIG_ENDIAN
|
||
|
#define DOBIG4 c ^= *++buf4; \
|
||
|
c = crc_table[4][c & 0xff] ^ crc_table[5][(c >> 8) & 0xff] ^ \
|
||
|
crc_table[6][(c >> 16) & 0xff] ^ crc_table[7][c >> 24]
|
||
|
#define DOBIG32 DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4
|
||
|
|
||
|
/* ========================================================================= */
|
||
|
static uint32_t crc32_big(uint32_t crc, const unsigned char *buf, z_off64_t len) {
|
||
|
register uint32_t c;
|
||
|
register const uint32_t *buf4;
|
||
|
|
||
|
c = ZSWAP32(crc);
|
||
|
c = ~c;
|
||
|
while (len && ((ptrdiff_t)buf & 3)) {
|
||
|
c = crc_table[4][(c >> 24) ^ *buf++] ^ (c << 8);
|
||
|
len--;
|
||
|
}
|
||
|
|
||
|
buf4 = (const uint32_t *)(const void *)buf;
|
||
|
buf4--;
|
||
|
|
||
|
#ifndef UNROLL_LESS
|
||
|
while (len >= 32) {
|
||
|
DOBIG32;
|
||
|
len -= 32;
|
||
|
}
|
||
|
#endif
|
||
|
|
||
|
while (len >= 4) {
|
||
|
DOBIG4;
|
||
|
len -= 4;
|
||
|
}
|
||
|
buf4++;
|
||
|
buf = (const unsigned char *)buf4;
|
||
|
|
||
|
if (len) do {
|
||
|
c = crc_table[4][(c >> 24) ^ *buf++] ^ (c << 8);
|
||
|
} while (--len);
|
||
|
c = ~c;
|
||
|
return ZSWAP32(c);
|
||
|
}
|
||
|
#endif /* BYTE_ORDER == BIG_ENDIAN */
|
||
|
|
||
|
|
||
|
#define GF2_DIM 32 /* dimension of GF(2) vectors (length of CRC) */
|
||
|
|
||
|
/* ========================================================================= */
|
||
|
static uint32_t gf2_matrix_times(uint32_t *mat, uint32_t vec) {
|
||
|
uint32_t sum;
|
||
|
|
||
|
sum = 0;
|
||
|
while (vec) {
|
||
|
if (vec & 1)
|
||
|
sum ^= *mat;
|
||
|
vec >>= 1;
|
||
|
mat++;
|
||
|
}
|
||
|
return sum;
|
||
|
}
|
||
|
|
||
|
/* ========================================================================= */
|
||
|
static void gf2_matrix_square(uint32_t *square, uint32_t *mat) {
|
||
|
int n;
|
||
|
|
||
|
for (n = 0; n < GF2_DIM; n++)
|
||
|
square[n] = gf2_matrix_times(mat, mat[n]);
|
||
|
}
|
||
|
|
||
|
/* ========================================================================= */
|
||
|
static uint32_t crc32_combine_(uint32_t crc1, uint32_t crc2, z_off64_t len2) {
|
||
|
int n;
|
||
|
uint32_t row;
|
||
|
uint32_t even[GF2_DIM]; /* even-power-of-two zeros operator */
|
||
|
uint32_t odd[GF2_DIM]; /* odd-power-of-two zeros operator */
|
||
|
|
||
|
/* degenerate case (also disallow negative lengths) */
|
||
|
if (len2 <= 0)
|
||
|
return crc1;
|
||
|
|
||
|
/* put operator for one zero bit in odd */
|
||
|
odd[0] = 0xedb88320; /* CRC-32 polynomial */
|
||
|
row = 1;
|
||
|
for (n = 1; n < GF2_DIM; n++) {
|
||
|
odd[n] = row;
|
||
|
row <<= 1;
|
||
|
}
|
||
|
|
||
|
/* put operator for two zero bits in even */
|
||
|
gf2_matrix_square(even, odd);
|
||
|
|
||
|
/* put operator for four zero bits in odd */
|
||
|
gf2_matrix_square(odd, even);
|
||
|
|
||
|
/* apply len2 zeros to crc1 (first square will put the operator for one
|
||
|
zero byte, eight zero bits, in even) */
|
||
|
do {
|
||
|
/* apply zeros operator for this bit of len2 */
|
||
|
gf2_matrix_square(even, odd);
|
||
|
if (len2 & 1)
|
||
|
crc1 = gf2_matrix_times(even, crc1);
|
||
|
len2 >>= 1;
|
||
|
|
||
|
/* if no more bits set, then done */
|
||
|
if (len2 == 0)
|
||
|
break;
|
||
|
|
||
|
/* another iteration of the loop with odd and even swapped */
|
||
|
gf2_matrix_square(odd, even);
|
||
|
if (len2 & 1)
|
||
|
crc1 = gf2_matrix_times(odd, crc1);
|
||
|
len2 >>= 1;
|
||
|
|
||
|
/* if no more bits set, then done */
|
||
|
} while (len2 != 0);
|
||
|
|
||
|
/* return combined crc */
|
||
|
crc1 ^= crc2;
|
||
|
return crc1;
|
||
|
}
|
||
|
|
||
|
/* ========================================================================= */
|
||
|
uint32_t ZEXPORT crc32_combine(uint32_t crc1, uint32_t crc2, z_off_t len2) {
|
||
|
return crc32_combine_(crc1, crc2, len2);
|
||
|
}
|
||
|
|
||
|
uint32_t ZEXPORT crc32_combine64(uint32_t crc1, uint32_t crc2, z_off64_t len2) {
|
||
|
return crc32_combine_(crc1, crc2, len2);
|
||
|
}
|
||
|
|
||
|
|
||
|
#ifdef X86_PCLMULQDQ_CRC
|
||
|
#include "arch/x86/x86.h"
|
||
|
extern void ZLIB_INTERNAL crc_fold_init(deflate_state *const s);
|
||
|
extern void ZLIB_INTERNAL crc_fold_copy(deflate_state *const s,
|
||
|
unsigned char *dst, const unsigned char *src, long len);
|
||
|
extern uint32_t ZLIB_INTERNAL crc_fold_512to32(deflate_state *const s);
|
||
|
#endif
|
||
|
|
||
|
ZLIB_INTERNAL void crc_reset(deflate_state *const s) {
|
||
|
#ifdef X86_PCLMULQDQ_CRC
|
||
|
if (x86_cpu_has_pclmulqdq) {
|
||
|
crc_fold_init(s);
|
||
|
return;
|
||
|
}
|
||
|
#endif
|
||
|
s->strm->adler = crc32(0L, Z_NULL, 0);
|
||
|
}
|
||
|
|
||
|
ZLIB_INTERNAL void crc_finalize(deflate_state *const s) {
|
||
|
#ifdef X86_PCLMULQDQ_CRC
|
||
|
if (x86_cpu_has_pclmulqdq)
|
||
|
s->strm->adler = crc_fold_512to32(s);
|
||
|
#endif
|
||
|
}
|
||
|
|
||
|
ZLIB_INTERNAL void copy_with_crc(z_stream *strm, unsigned char *dst, long size) {
|
||
|
#ifdef X86_PCLMULQDQ_CRC
|
||
|
if (x86_cpu_has_pclmulqdq) {
|
||
|
crc_fold_copy(strm->state, dst, strm->next_in, size);
|
||
|
return;
|
||
|
}
|
||
|
#endif
|
||
|
memcpy(dst, strm->next_in, size);
|
||
|
strm->adler = crc32(strm->adler, dst, size);
|
||
|
}
|
||
|
|