+/* Licensed under LGPLv2.1+ - see LICENSE file for details */
#include "crcsync.h"
#include <ccan/crc/crc.h>
#include <string.h>
#include <assert.h>
#include <stdbool.h>
+/* FIXME: That 64-bit CRC takes a while to warm the lower bits. Do
+ * some quantitative tests and replace it? Meanwhile, use upper bits. */
+static uint64_t mask_of(unsigned int crcbits)
+{
+ return -1ULL << (64 - crcbits);
+}
+
void crc_of_blocks(const void *data, size_t len, unsigned int block_size,
- unsigned int crcbits, uint32_t crc[])
+ unsigned int crcbits, uint64_t crc[])
{
unsigned int i;
const uint8_t *buf = data;
- uint32_t crcmask = crcbits < 32 ? (1 << crcbits) - 1 : 0xFFFFFFFF;
+ uint64_t crcmask = mask_of(crcbits);
for (i = 0; len >= block_size; i++) {
- crc[i] = (crc32c(0, buf, block_size) & crcmask);
+ crc[i] = (crc64_iso(0, buf, block_size) & crcmask);
buf += block_size;
len -= block_size;
}
if (len)
- crc[i] = (crc32c(0, buf, len) & crcmask);
+ crc[i] = (crc64_iso(0, buf, len) & crcmask);
}
struct crc_context {
size_t block_size;
- uint32_t crcmask;
+ uint64_t crcmask;
/* Saved old buffer bytes (block_size bytes). */
void *buffer;
size_t buffer_start, buffer_end;
/* Progress so far. */
- uint32_t running_crc;
+ uint64_t running_crc;
size_t literal_bytes;
size_t total_bytes;
int have_match;
/* Final block is special (if a different size) */
size_t tail_size;
- uint32_t tail_crc;
+ uint64_t tail_crc;
/* Uncrc tab. */
- uint32_t uncrc_tab[256];
+ uint64_t uncrc_tab[256];
/* This doesn't count the last CRC. */
unsigned int num_crcs;
- uint32_t crc[];
+ uint64_t crc[];
};
/* Calculate the how the crc changes when we take a give char out of the
* crc'd area. */
-static void init_uncrc_tab(uint32_t uncrc_tab[], unsigned int wsize)
+static void init_uncrc_tab(uint64_t uncrc_tab[], unsigned int wsize)
{
unsigned int i;
- uint32_t part_crc;
+ uint64_t part_crc;
uint8_t buffer[wsize];
/* Calculate crc(buffer+1, wsize-1) once, since it doesn't change. */
memset(buffer, 0, wsize);
- part_crc = crc32c(0, buffer+1, wsize-1);
+ part_crc = crc64_iso(0, buffer+1, wsize-1);
for (i = 0; i < 256; i++) {
buffer[0] = i;
- uncrc_tab[i] = (crc32c(0, buffer, wsize) ^ part_crc);
+ uncrc_tab[i] = (crc64_iso(0, buffer, wsize) ^ part_crc);
}
}
struct crc_context *crc_context_new(size_t block_size, unsigned crcbits,
- const uint32_t crc[], unsigned num_crcs,
+ const uint64_t crc[], unsigned num_crcs,
size_t tail_size)
{
struct crc_context *ctx;
if (tail_size)
ctx->tail_crc = crc[--num_crcs];
- /* Technically, 1 << 32 is undefined. */
- if (crcbits >= 32)
- ctx->crcmask = 0xFFFFFFFF;
- else
- ctx->crcmask = (1 << crcbits)-1;
+ ctx->crcmask = mask_of(crcbits);
ctx->num_crcs = num_crcs;
memcpy(ctx->crc, crc, sizeof(crc[0])*num_crcs);
ctx->buffer_end = 0;
return (ctx->running_crc & ctx->crcmask) == ctx->tail_crc;
}
-static uint32_t crc_add_byte(uint32_t crc, uint8_t newbyte)
+static uint64_t crc_add_byte(uint64_t crc, uint8_t newbyte)
{
- return crc32c(crc, &newbyte, 1);
+ return crc64_iso(crc, &newbyte, 1);
}
-static uint32_t crc_remove_byte(uint32_t crc, uint8_t oldbyte,
- const uint32_t uncrc_tab[])
+static uint64_t crc_remove_byte(uint64_t crc, uint8_t oldbyte,
+ const uint64_t uncrc_tab[])
{
return crc ^ uncrc_tab[oldbyte];
}
-static uint32_t crc_roll(uint32_t crc, uint8_t oldbyte, uint8_t newbyte,
- const uint32_t uncrc_tab[])
+static uint64_t crc_roll(uint64_t crc, uint8_t oldbyte, uint8_t newbyte,
+ const uint64_t uncrc_tab[])
{
return crc_add_byte(crc_remove_byte(crc, oldbyte, uncrc_tab), newbyte);
}
/* old is the trailing edge of the checksum window. */
if (buffer_size(ctx) >= ctx->block_size)
- old = ctx->buffer + ctx->buffer_start;
+ old = (uint8_t *)ctx->buffer + ctx->buffer_start;
else
old = NULL;
ctx->uncrc_tab);
old++;
/* End of stored buffer? Start on data they gave us. */
- if (old == ctx->buffer + ctx->buffer_end)
+ if (old == (uint8_t *)ctx->buffer + ctx->buffer_end)
old = buf;
} else {
ctx->running_crc = crc_add_byte(ctx->running_crc, *p);
/* Move down old data if we don't have room. */
if (ctx->buffer_end + len > ctx->block_size) {
- memmove(ctx->buffer, ctx->buffer + ctx->buffer_start,
+ memmove(ctx->buffer,
+ (uint8_t *)ctx->buffer + ctx->buffer_start,
buffer_size(ctx));
ctx->buffer_end -= ctx->buffer_start;
ctx->buffer_start = 0;
}
/* Copy len bytes from tail of buffer. */
- memcpy(ctx->buffer + ctx->buffer_end, buf + buflen - len, len);
+ memcpy((uint8_t *)ctx->buffer + ctx->buffer_end,
+ (const uint8_t *)buf + buflen - len, len);
ctx->buffer_end += len;
assert(buffer_size(ctx) <= ctx->block_size);
}