github.com/wallyworld/juju@v0.0.0-20161013125918-6cf1bc9d917a/resource/service.go (about)

     1  // Copyright 2016 Canonical Ltd.
     2  // Licensed under the AGPLv3, see LICENCE file for details.
     3  
     4  package resource
     5  
     6  import (
     7  	"github.com/juju/errors"
     8  	"gopkg.in/juju/charm.v6-unstable/resource"
     9  	"gopkg.in/juju/names.v2"
    10  )
    11  
    12  // ServiceResources contains the list of resources for the application and all its
    13  // units.
    14  type ServiceResources struct {
    15  	// Resources are the current version of the resource for the application that
    16  	// resource-get will retrieve.
    17  	Resources []Resource
    18  
    19  	// CharmStoreResources provides the resource info from the charm
    20  	// store for each of the application's resources. The information from
    21  	// the charm store is current as of the last time the charm store
    22  	// was polled. Each entry here corresponds to the same indexed entry
    23  	// in the Resources field.
    24  	CharmStoreResources []resource.Resource
    25  
    26  	// UnitResources reports the currenly-in-use version of resources for each
    27  	// unit.
    28  	UnitResources []UnitResources
    29  }
    30  
    31  // Updates returns the list of charm store resources corresponding to
    32  // the application's resources that are out of date. Note that there must be
    33  // a charm store resource for each of the application resources and
    34  // vice-versa. If they are out of sync then an error is returned.
    35  func (sr ServiceResources) Updates() ([]resource.Resource, error) {
    36  	storeResources, err := sr.alignStoreResources()
    37  	if err != nil {
    38  		return nil, errors.Trace(err)
    39  	}
    40  
    41  	var updates []resource.Resource
    42  	for i, res := range sr.Resources {
    43  		if res.Origin != resource.OriginStore {
    44  			continue
    45  		}
    46  		csRes := storeResources[i]
    47  		// If the revision is the same then all the other info must be.
    48  		if res.Revision == csRes.Revision {
    49  			continue
    50  		}
    51  		updates = append(updates, csRes)
    52  	}
    53  	return updates, nil
    54  }
    55  
    56  func (sr ServiceResources) alignStoreResources() ([]resource.Resource, error) {
    57  	if len(sr.CharmStoreResources) > len(sr.Resources) {
    58  		return nil, errors.Errorf("have more charm store resources than application resources")
    59  	}
    60  	if len(sr.CharmStoreResources) < len(sr.Resources) {
    61  		return nil, errors.Errorf("have fewer charm store resources than application resources")
    62  	}
    63  
    64  	var store []resource.Resource
    65  	for _, res := range sr.Resources {
    66  		found := false
    67  		for _, chRes := range sr.CharmStoreResources {
    68  			if chRes.Name == res.Name {
    69  				store = append(store, chRes)
    70  				found = true
    71  				break
    72  			}
    73  		}
    74  		if !found {
    75  			return nil, errors.Errorf("charm store resource %q not found", res.Name)
    76  		}
    77  	}
    78  	return store, nil
    79  }
    80  
    81  // UnitResources conains the list of resources used by a unit.
    82  type UnitResources struct {
    83  	// Tag is the tag of the unit.
    84  	Tag names.UnitTag
    85  
    86  	// Resources are the resource versions currently in use by this unit.
    87  	Resources []Resource
    88  
    89  	// DownloadProgress indicates the number of bytes of the unit's
    90  	// resources, identified by name, that have been downloaded so far
    91  	// by the uniter. This only applies to resources that are currently
    92  	// being downloaded to the unit. All other resources for the unit
    93  	// will not be found in the map.
    94  	DownloadProgress map[string]int64
    95  }