ducky/devices
2015-11-29
Parent:03c49b4d3d9f
ducky/devices/memstore.go
Set up DeleteDevices in Memstore. Implement the DeleteDevices method for our Memstore, removing the Devices specified by the passed IDs. Also, create a simple test that verifies that when Devices are deleted, only the Devices you intend to delete are actually deleted. Further tests should be written to verify that this extends to ListDevicesByOwner (e.g., deleted devices will not be returned when listing them), CreateDevices (e.g., will not result in an ErrDeviceAlreadyExists error), and UpdateDevice (e.g., will return an ErrDeviceNotFound error after the Device is deleted). But for now, we're confident that it works in the simplest possible case.
| paddy@4 | 1 package devices |
| paddy@4 | 2 |
| paddy@4 | 3 import ( |
| paddy@4 | 4 "sync" |
| paddy@4 | 5 |
| paddy@4 | 6 "code.secondbit.org/uuid.hg" |
| paddy@4 | 7 "golang.org/x/net/context" |
| paddy@4 | 8 ) |
| paddy@4 | 9 |
| paddy@12 | 10 // Memstore is an in-memory implementation of Storer, and should |
| paddy@12 | 11 // only be used for testing or for temporary local servers. |
| paddy@4 | 12 type Memstore struct { |
| paddy@4 | 13 devices map[string]Device |
| paddy@4 | 14 lock sync.RWMutex |
| paddy@4 | 15 } |
| paddy@4 | 16 |
| paddy@12 | 17 // NewMemstore returns a Memstore that is ready to be used as a |
| paddy@12 | 18 // Storer implementation. |
| paddy@4 | 19 func NewMemstore() *Memstore { |
| paddy@4 | 20 return &Memstore{ |
| paddy@4 | 21 devices: map[string]Device{}, |
| paddy@4 | 22 } |
| paddy@4 | 23 } |
| paddy@4 | 24 |
| paddy@12 | 25 // GetDevices returns any Devices in the Memstore that match the |
| paddy@12 | 26 // passed IDs. If an ID cannot be matched to a Device in the |
| paddy@12 | 27 // Memstore, it is ignored. The result is a map, with the values |
| paddy@12 | 28 // being the Devices that could be found, and the keys being the |
| paddy@12 | 29 // result of the String() method for each Device's ID. |
| paddy@12 | 30 // |
| paddy@12 | 31 // An empty map is a possible response, if none of the IDs could |
| paddy@12 | 32 // be found. |
| paddy@4 | 33 func (m *Memstore) GetDevices(ids []uuid.ID, c context.Context) (map[string]Device, error) { |
| paddy@4 | 34 m.lock.RLock() |
| paddy@4 | 35 defer m.lock.RUnlock() |
| paddy@4 | 36 |
| paddy@4 | 37 results := map[string]Device{} |
| paddy@4 | 38 |
| paddy@4 | 39 for _, id := range ids { |
| paddy@4 | 40 device, ok := m.devices[id.String()] |
| paddy@4 | 41 if !ok { |
| paddy@4 | 42 continue |
| paddy@4 | 43 } |
| paddy@4 | 44 results[id.String()] = device |
| paddy@4 | 45 } |
| paddy@4 | 46 return results, nil |
| paddy@4 | 47 } |
| paddy@4 | 48 |
| paddy@12 | 49 // UpdateDevice applies the passed DeviceChange to the Device |
| paddy@12 | 50 // in the Memstore specified by the DeviceChange's DeviceID |
| paddy@12 | 51 // property. If no Device in the Memstore matches the DeviceChange's |
| paddy@12 | 52 // DeviceID property, then an ErrDeviceNotFound error will be |
| paddy@12 | 53 // returned. |
| paddy@4 | 54 func (m *Memstore) UpdateDevice(change DeviceChange, c context.Context) error { |
| paddy@10 | 55 m.lock.Lock() |
| paddy@10 | 56 defer m.lock.Unlock() |
| paddy@10 | 57 |
| paddy@10 | 58 device, ok := m.devices[change.DeviceID.String()] |
| paddy@10 | 59 if !ok { |
| paddy@11 | 60 return ErrDeviceNotFound |
| paddy@10 | 61 } |
| paddy@10 | 62 |
| paddy@10 | 63 device = ApplyChange(device, change) |
| paddy@10 | 64 m.devices[change.DeviceID.String()] = device |
| paddy@10 | 65 |
| paddy@4 | 66 return nil |
| paddy@4 | 67 } |
| paddy@4 | 68 |
| paddy@12 | 69 // DeleteDevices will remove any Devices from the Memstore that match |
| paddy@12 | 70 // the IDs passed in. If an ID can't be matched to a Device in the |
| paddy@12 | 71 // Memstore, then it is ignored. |
| paddy@14 | 72 func (m *Memstore) DeleteDevices(ids []uuid.ID, c context.Context) error { |
| paddy@14 | 73 m.lock.Lock() |
| paddy@14 | 74 defer m.lock.Unlock() |
| paddy@14 | 75 |
| paddy@14 | 76 for _, id := range ids { |
| paddy@14 | 77 delete(m.devices, id.String()) |
| paddy@14 | 78 } |
| paddy@14 | 79 |
| paddy@4 | 80 return nil |
| paddy@4 | 81 } |
| paddy@4 | 82 |
| paddy@12 | 83 // CreateDevices stores the passed devices in the Memstore as a single |
| paddy@12 | 84 // transaction. If a Device's ID already exists in the Memstore, an |
| paddy@12 | 85 // ErrDeviceAlreadyExists error with that Device's ID is returned, and |
| paddy@12 | 86 // none of the passed Devices are stored. |
| paddy@4 | 87 func (m *Memstore) CreateDevices(devices []Device, c context.Context) error { |
| paddy@4 | 88 m.lock.Lock() |
| paddy@4 | 89 defer m.lock.Unlock() |
| paddy@4 | 90 |
| paddy@4 | 91 for _, device := range devices { |
| paddy@5 | 92 if _, ok := m.devices[device.ID.String()]; ok { |
| paddy@5 | 93 return ErrDeviceAlreadyExists(device.ID) |
| paddy@5 | 94 } |
| paddy@5 | 95 } |
| paddy@5 | 96 |
| paddy@5 | 97 for _, device := range devices { |
| paddy@4 | 98 m.devices[device.ID.String()] = device |
| paddy@4 | 99 } |
| paddy@4 | 100 return nil |
| paddy@4 | 101 } |
| paddy@4 | 102 |
| paddy@12 | 103 // ListDevicesByOwner returns all the Devices in the Memstore that have an |
| paddy@12 | 104 // Owner property that matches the passed ID. If no Devices have an Owner |
| paddy@12 | 105 // property matching the passed ID, an empty slice is returned. |
| paddy@12 | 106 // |
| paddy@12 | 107 // ListDevicesByOwner does not guarantee any sort order for the Devices. |
| paddy@4 | 108 func (m *Memstore) ListDevicesByOwner(user uuid.ID, c context.Context) ([]Device, error) { |
| paddy@8 | 109 var devices []Device |
| paddy@8 | 110 for _, device := range m.devices { |
| paddy@8 | 111 if !device.Owner.Equal(user) { |
| paddy@8 | 112 continue |
| paddy@8 | 113 } |
| paddy@8 | 114 devices = append(devices, device) |
| paddy@8 | 115 } |
| paddy@8 | 116 return devices, nil |
| paddy@4 | 117 } |