C++ bswap_64函数代码示例

// Read weights and load into factor graph
long long read_weights(string filename, dd::FactorGraph &fg)
{
	ifstream file;
    file.open(filename.c_str(), ios::in | ios::binary);
    long long count = 0;
    long long id;
    bool isfixed;
    char padding;
    double initial_value;
    while (file.good()) {
    	// read fields
        file.read((char *)&id, 8);
        file.read((char *)&padding, 1);
        if (!file.read((char *)&initial_value, 8)) break;
        // convert endian
        id = bswap_64(id);
        isfixed = padding;
        long long tmp = bswap_64(*(uint64_t *)&initial_value);
        initial_value = *(double *)&tmp;
        // load into factor graph
        fg.weights[fg.c_nweight] = dd::Weight(id, initial_value, isfixed);
		fg.c_nweight++;
		count++;
    }
    file.close();
    return count;
}

int eMPEGStreamInformation::load(const char *filename)
{
	m_filename = filename;
	if (m_structure_read)
		fclose(m_structure_read);
	m_structure_read = fopen((std::string(m_filename) + ".sc").c_str(), "rb");
	FILE *f = fopen((std::string(m_filename) + ".ap").c_str(), "rb");
	if (!f)
		return -1;
	m_access_points.clear();
	m_pts_to_offset.clear();
	while (1)
	{
		unsigned long long d[2];
		if (fread(d, sizeof(d), 1, f) < 1)
			break;
		
#if BYTE_ORDER == LITTLE_ENDIAN
		d[0] = bswap_64(d[0]);
		d[1] = bswap_64(d[1]);
#endif
		m_access_points[d[0]] = d[1];
		m_pts_to_offset.insert(std::pair<pts_t,off_t>(d[1], d[0]));
	}
	fclose(f);
	fixupDiscontinuties();
	return 0;
}

static fsal_status_t wire_to_host(struct fsal_export *exp_hdl,
				  fsal_digesttype_t in_type,
				  struct gsh_buffdesc *fh_desc,
				  int flags)
{
	size_t fh_min;
	uint64_t *hashkey;
	ushort *len;

	fh_min = 1;

	if (fh_desc->len < fh_min) {
		LogMajor(COMPONENT_FSAL,
			 "Size mismatch for handle.  should be >= %zu, got %zu",
			 fh_min, fh_desc->len);
		return fsalstat(ERR_FSAL_SERVERFAULT, 0);
	}
	hashkey = (uint64_t *)fh_desc->addr;
	len = (ushort *)((char *)hashkey + sizeof(uint64_t));
	if (flags & FH_FSAL_BIG_ENDIAN) {
#if (BYTE_ORDER != BIG_ENDIAN)
		*len = bswap_16(*len);
		*hashkey = bswap_64(*hashkey);
#endif
	} else {
#if (BYTE_ORDER == BIG_ENDIAN)
		*len = bswap_16(*len);
		*hashkey = bswap_64(*hashkey);
#endif
	}
	return fsalstat(ERR_FSAL_NO_ERROR, 0);
}

long long read_factors(string filename, dd::FactorGraph &fg)
{
    ifstream file;
    file.open(filename.c_str(), ios::in | ios::binary);
    long long count = 0;
    long long id;
    long long weightid;
    short type;
    long long edge_count;
    while (file.good()) {
        file.read((char *)&id, 8);
        file.read((char *)&weightid, 8);
        file.read((char *)&type, 2);
        if (!file.read((char *)&edge_count, 8)) break;
        id = bswap_64(id);
        weightid = bswap_64(weightid);
        type = bswap_16(type);
        edge_count = bswap_64(edge_count);
        count++;
        fg.factors[fg.c_nfactor] = dd::Factor(id, weightid, type, edge_count);
        fg.c_nfactor ++;
    }
    file.close();
    return count;
}

 int64_t bigint::to_int64() const
 {
   FC_ASSERT(BN_num_bits(n) <= 63);
   size_t size = BN_num_bytes(n);
   uint64_t abs_value = 0;
   BN_bn2bin(n, (unsigned char*)&abs_value + (sizeof(uint64_t) - size));
   return BN_is_negative(n) ? -(int64_t)bswap_64(abs_value) : bswap_64(abs_value);
 }

static void ocfs2_swap_extent_block_header(struct ocfs2_extent_block *eb)
{

	eb->h_suballoc_slot = bswap_16(eb->h_suballoc_slot);
	eb->h_suballoc_bit  = bswap_16(eb->h_suballoc_bit);
	eb->h_fs_generation = bswap_32(eb->h_fs_generation);
	eb->h_blkno         = bswap_64(eb->h_blkno);
	eb->h_next_leaf_blk = bswap_64(eb->h_next_leaf_blk);
}

void Memcached::dump_extra(const PacketHeader *header, const unsigned char *b, size_t len)
{
  static char extra[1024];
  switch (header->opcode_) {
    case MC_GET:
    case MC_GETQ:
    case MC_GETK:
    case MC_GETKQ:
      snprintf(extra, sizeof(extra),
          "extra: { "
          "flags: 0x%x "
          "}\n",
          bswap_32(*reinterpret_cast<const uint32_t*>(b)));
      break;
    case MC_SET:
    case MC_ADD:
    case MC_REP:
    case MC_SETQ:
    case MC_ADDQ:
    case MC_REPQ:
      snprintf(extra, sizeof(extra),
          "extra: { "
          "flags: 0x%x, "
          "expire: %d "
          "}\n",
          bswap_32(*reinterpret_cast<const uint32_t*>(b)),
          bswap_32(*reinterpret_cast<const int32_t*>(b + 4)));
      break;
    case MC_INC:
    case MC_DEC:
    case MC_INCQ:
    case MC_DECQ:
      snprintf(extra, sizeof(extra),
          "extra: { "
          "delta: %lu, "
          "init: %lu, "
          "expire: %d "
          "}\n",
          bswap_64(*reinterpret_cast<const uint64_t*>(b)),
          bswap_64(*reinterpret_cast<const uint64_t*>(b + 8)),
          bswap_32(*reinterpret_cast<const int32_t*>(b + 12)));
      break;
    case MC_FLUSH:
    case MC_FLUSHQ:
    case MC_TOUCH:
    case MC_GAT:
    case MC_GATQ:
      snprintf(extra, sizeof(extra),
          "extra: { "
          "expire: %d "
          "}\n",
          bswap_32(*reinterpret_cast<const int32_t*>(b)));
      break;
  }
  fprintf(stdout, "%s\n", extra);
}

static void store_chunk(struct analyze_ctx *analyze,
			const struct scan_chunk_data *chunk_data) {
    int i;
    sha256_ctx sha256;
    unsigned char sha256_digest[32];
    char sha256_digest_string[65];
    int chunk_size = 0;

    sha256_init(&sha256);
    for (i=0; i<2; i++) {
	chunk_size +=  chunk_data[i].size;
	if (chunk_data[i].buf && chunk_data[i].size)
	    sha256_update(&sha256, chunk_data[i].buf, chunk_data[i].size);
    }
    sha256_final(&sha256, sha256_digest);
    sprintf(sha256_digest_string, "%016" PRIx64
	                          "%016" PRIx64
	                          "%016" PRIx64
	                          "%016" PRIx64,
	    bswap_64(*(uint64_t *)&sha256_digest[0]),
	    bswap_64(*(uint64_t *)&sha256_digest[8]),
	    bswap_64(*(uint64_t *)&sha256_digest[16]),
	    bswap_64(*(uint64_t *)&sha256_digest[24]));
    if (sqlite3_bind_text(analyze->db_insert_stmt, 1, sha256_digest_string, -1,
		SQLITE_STATIC) != SQLITE_OK) {
	print_sqlite3_error(analyze->db);
	abort();
    }
    if (sqlite3_bind_int64(analyze->db_insert_stmt, 3, analyze->offset) !=
	    SQLITE_OK) {
	print_sqlite3_error(analyze->db);
	abort();
    }
    if (sqlite3_bind_int(analyze->db_insert_stmt, 4, chunk_size) != SQLITE_OK) {
	print_sqlite3_error(analyze->db);
	abort();
    }
    if (sqlite3_step(analyze->db_insert_stmt) != SQLITE_DONE) {
	print_sqlite3_error(analyze->db);
	abort();
    }
    if (sqlite3_reset(analyze->db_insert_stmt) != SQLITE_OK) {
	print_sqlite3_error(analyze->db);
	abort();
    }
#if 0
    printf("%016lx%016lx%016lx%016lx %d\n",
	    bswap64(*(uint64_t *)&sha256_digest[0]),
	    bswap64(*(uint64_t *)&sha256_digest[8]),
	    bswap64(*(uint64_t *)&sha256_digest[16]),
	    bswap64(*(uint64_t *)&sha256_digest[24]),
	    chunk_size);
#endif

    analyze->offset += chunk_size;
}

void ocfs2_swap_disk_heartbeat_block(struct o2hb_disk_heartbeat_block *hb)
{
	if (cpu_is_little_endian)
		return;

	hb->hb_seq        = bswap_64(hb->hb_seq);
	hb->hb_cksum      = bswap_32(hb->hb_cksum);
	hb->hb_generation = bswap_64(hb->hb_generation);
	hb->hb_dead_ms    = bswap_32(hb->hb_dead_ms);
}

static void ocfs2_swap_group_desc_header(struct ocfs2_group_desc *gd)
{
	gd->bg_size = bswap_16(gd->bg_size);
	gd->bg_bits = bswap_16(gd->bg_bits);
	gd->bg_free_bits_count = bswap_16(gd->bg_free_bits_count);
	gd->bg_chain = bswap_16(gd->bg_chain);
	gd->bg_generation = bswap_32(gd->bg_generation);
	gd->bg_next_group = bswap_64(gd->bg_next_group);
	gd->bg_parent_dinode = bswap_64(gd->bg_parent_dinode);
	gd->bg_blkno = bswap_64(gd->bg_blkno);
}

static
void KColumnIdx1Swap ( KColBlockLoc *buffer, uint32_t count )
{
    uint32_t i;
    for ( i = 0; i < count; ++ i )
    {
        buffer [ i ] . pg = bswap_64 ( buffer [ i ] . pg );
        buffer [ i ] . u . gen = bswap_32 ( buffer [ i ] . u . gen );
        buffer [ i ] . id_range = bswap_32 ( buffer [ i ] . id_range );
        buffer [ i ] . start_id = bswap_64 ( buffer [ i ] . start_id );
    }
}

int
write_u64(FILE*ofile,u64_t*buffer,size_t count)
{
size_t i;
int res;

for(i= 0;i<count;i++)
buffer[i]= bswap_64(buffer[i]);
res= fwrite(buffer,sizeof(*buffer),count,ofile);
for(i= 0;i<count;i++)
buffer[i]= bswap_64(buffer[i]);
return res;
}

void eMPEGStreamInformation::writeStructureEntry(off_t offset, structure_data data)
{
	unsigned long long d[2];
#if BYTE_ORDER == BIG_ENDIAN
	d[0] = offset;
	d[1] = data;
#else
	d[0] = bswap_64(offset);
	d[1] = bswap_64(data);
#endif
	if (m_structure_write)
		fwrite(d, sizeof(d), 1, m_structure_write);
}

void ocfs2_swap_group_desc(struct ocfs2_group_desc *gd)
{
	if (cpu_is_little_endian)
		return;

	gd->bg_size = bswap_16(gd->bg_size);
	gd->bg_bits = bswap_16(gd->bg_bits);
	gd->bg_free_bits_count = bswap_16(gd->bg_free_bits_count);
	gd->bg_chain = bswap_16(gd->bg_chain);
	gd->bg_generation = bswap_32(gd->bg_generation);
	gd->bg_next_group = bswap_64(gd->bg_next_group);
	gd->bg_parent_dinode = bswap_64(gd->bg_parent_dinode);
	gd->bg_blkno = bswap_64(gd->bg_blkno);
}

long long read_edges(string filename, dd::FactorGraph &fg)
{
    ifstream file;
    file.open(filename.c_str(), ios::in | ios::binary);
    long long count = 0;
    long long variable_id;
    long long factor_id;
    long long position;
    bool ispositive;
    char padding;
    long long equal_predicate;
    while (file.good()) {
        // read fields
        file.read((char *)&variable_id, 8);
        file.read((char *)&factor_id, 8);
        file.read((char *)&position, 8);
        file.read((char *)&padding, 1);
        if (!file.read((char *)&equal_predicate, 8)) break;
        variable_id = bswap_64(variable_id);
        factor_id = bswap_64(factor_id);
        position = bswap_64(position);
        ispositive = padding;
        equal_predicate = bswap_64(equal_predicate);
        count++;

        // wrong id
    	if(variable_id >= fg.n_var || variable_id < 0){
    	  assert(false);
    	}

    	if(factor_id >= fg.n_factor || factor_id < 0){
    	  std::cout << "wrong fid = " << factor_id << std::endl;
    	  assert(false);
        }

        // add variables to factors
        if (fg.variables[variable_id].domain_type == DTYPE_BOOLEAN) {
            fg.factors[factor_id].tmp_variables.push_back(
                dd::VariableInFactor(variable_id, fg.variables[variable_id].upper_bound, variable_id, position, ispositive));
        } else {
            fg.factors[factor_id].tmp_variables.push_back(
                dd::VariableInFactor(variable_id, position, ispositive, equal_predicate));
        }
        fg.variables[variable_id].tmp_factor_ids.push_back(factor_id);

    }
    file.close();
    return count;   
}