Function file_checksum

checksum.c:401–538

}

void file_checksum(const char *fname, const STRUCT_STAT *st_p, char *sum)
{
	struct map_struct *buf;
	OFF_T i, len = st_p->st_size;
	int32 remainder;
	int fd;

	fd = do_open_checklinks(fname);
	if (fd == -1) {
		memset(sum, 0, file_sum_len);
		return;
	}

	buf = map_file(fd, len, MAX_MAP_SIZE, CHUNK_SIZE);

#ifdef USE_OPENSSL
	if (file_sum_evp_md) {
		static EVP_MD_CTX *evp = NULL;
		if (!evp && !(evp = EVP_MD_CTX_create()))
			out_of_memory("file_checksum");

		EVP_DigestInit_ex(evp, file_sum_evp_md, NULL);

		for (i = 0; i + CHUNK_SIZE <= len; i += CHUNK_SIZE)
			EVP_DigestUpdate(evp, (uchar *)map_ptr(buf, i, CHUNK_SIZE), CHUNK_SIZE);

		remainder = (int32)(len - i);
		if (remainder > 0)
			EVP_DigestUpdate(evp, (uchar *)map_ptr(buf, i, remainder), remainder);

		EVP_DigestFinal_ex(evp, (uchar *)sum, NULL);
	} else
#endif
	switch (file_sum_nni->num) {
#ifdef SUPPORT_XXHASH
	  case CSUM_XXH64: {
		static XXH64_state_t* state = NULL;
		if (!state && !(state = XXH64_createState()))
			out_of_memory("file_checksum");

		XXH64_reset(state, 0);

		for (i = 0; i + CHUNK_SIZE <= len; i += CHUNK_SIZE)
			XXH64_update(state, (uchar *)map_ptr(buf, i, CHUNK_SIZE), CHUNK_SIZE);

		remainder = (int32)(len - i);
		if (remainder > 0)
			XXH64_update(state, (uchar *)map_ptr(buf, i, remainder), remainder);

		SIVAL64(sum, 0, XXH64_digest(state));
		break;
	  }
#endif
#ifdef SUPPORT_XXH3
	  case CSUM_XXH3_64: {
		static XXH3_state_t* state = NULL;
		if (!state && !(state = XXH3_createState()))
			out_of_memory("file_checksum");