Returns the host cache configuration on the proxy host.

    service_instance
        Service instance (vim.ServiceInstance) of the vCenter/ESXi host.
        Default is None.

    .. code-block:: bash

        salt '*' vsphere.get_host_cache

def get_host_cache(service_instance=None):
    '''
    Returns the host cache configuration on the proxy host.

    service_instance
        Service instance (vim.ServiceInstance) of the vCenter/ESXi host.
        Default is None.

    .. code-block:: bash

        salt '*' vsphere.get_host_cache
    '''
    # Default to getting all disks if no filtering is done
    ret_dict = {}
    host_ref = _get_proxy_target(service_instance)
    hostname = __proxy__['esxi.get_details']()['esxi_host']
    hci = salt.utils.vmware.get_host_cache(host_ref)
    if not hci:
        log.debug('Host cache not configured on host \'%s\'', hostname)
        ret_dict['enabled'] = False
        return ret_dict

    # TODO Support multiple host cache info objects (on multiple datastores)
    return {'enabled': True,
            'datastore': {'name': hci.key.name},
            'swap_size': '{}MiB'.format(hci.swapSize)}