/** \ingroup msg_file_management
* \brief Write into a file (local or remote)
*
* \param size of the file to write
* \param fd is a the file descriptor
* \return the number of bytes successfully write or -1 if an error occurred
*/
sg_size_t MSG_file_write(msg_file_t fd, sg_size_t size)
{
msg_file_priv_t file_priv = MSG_file_priv(fd);
sg_size_t write_size, offset;
/* Find the host where the file is physically located (remote or local)*/
msg_storage_t storage_src =(msg_storage_t) xbt_lib_get_elm_or_null(storage_lib, file_priv->storageId);
msg_storage_priv_t storage_priv_src = MSG_storage_priv(storage_src);
msg_host_t attached_host = MSG_get_host_by_name(storage_priv_src->hostname);
if(strcmp(storage_priv_src->hostname, MSG_host_get_name(MSG_host_self()))){
/* the file is hosted on a remote host, initiate a communication between src and dest hosts for data transfer */
XBT_DEBUG("File is on %s remote host, initiate data transfer of %llu bytes.", storage_priv_src->hostname, size);
msg_host_t *m_host_list = NULL;
m_host_list = calloc(2, sizeof(msg_host_t));
m_host_list[0] = MSG_host_self();
m_host_list[1] = attached_host;
double flops_amount[] = { 0, 0 };
double bytes_amount[] = { 0, (double)size, 0, 0 };
msg_task_t task = MSG_parallel_task_create("file transfer for write", 2, m_host_list, flops_amount, bytes_amount, NULL);
msg_error_t transfer = MSG_parallel_task_execute(task);
MSG_task_destroy(task);
free(m_host_list);
if(transfer != MSG_OK){
if (transfer == MSG_HOST_FAILURE)
XBT_WARN("Transfer error, %s remote host just turned off!", MSG_host_get_name(attached_host));
if (transfer == MSG_TASK_CANCELED)
XBT_WARN("Transfer error, task has been canceled!");
return -1;
}
}
/* Write file on local or remote host */
offset = simcall_file_tell(file_priv->simdata->smx_file);
write_size = simcall_file_write(file_priv->simdata->smx_file, size, attached_host);
file_priv->size = offset+write_size;
return write_size;
}
sg_size_t File::tell() {
return simcall_file_tell(p_inferior);
}
/**
* \ingroup msg_file_management
* \brief Returns the current value of the position indicator of the file
*
* \param fd : file object that identifies the stream
* \return On success, the current value of the position indicator is returned.
*
*/
sg_size_t MSG_file_tell(msg_file_t fd)
{
msg_file_priv_t priv = MSG_file_priv(fd);
return simcall_file_tell(priv->simdata->smx_file);
}
