ducky/devices

Paddy 2015-12-22 Parent:a700ede02f91

18:b2fdf827758e Go to Latest

ducky/devices/devices.go

Add endpoint for retrieving devices. Add an endpoint for retrieving devices, either as a list or by ID. Stub endpoints for updating and deleting devices., along with TODOs marking them as things to still be completed. (Right now, accessing those endpoints is an insta-panic.) Simplify our handleCreateDevices by returning StatusUnauthorized if AuthUser fails, so we can reserve StatusForbidden for when auth succeeds but access is still denied. Also, delay the instantiation and allocation of a Response variable until we're actually going to use it. Create a handleGetDevices handler that authenticates the user, and if no ID is set, returns a list of all their Devices. If one or more IDs are set, only those Devices are returned. If ScopeViewPushToken is one of the scopes associated with the request, the push tokens for each Device will be included in the response. Otherwise, they will be omitted.

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paddy@0 1 package devices
paddy@0 2
paddy@0 3 import (
paddy@0 4 "errors"
paddy@5 5 "fmt"
paddy@0 6 "log"
paddy@0 7 "time"
paddy@0 8
paddy@0 9 "golang.org/x/net/context"
paddy@0 10
paddy@0 11 "code.secondbit.org/uuid.hg"
paddy@0 12 )
paddy@0 13
paddy@0 14 var (
paddy@0 15 // ErrDeviceNotFound is returned when the specified device couldn't be found.
paddy@0 16 ErrDeviceNotFound = errors.New("device not found")
paddy@0 17 )
paddy@0 18
paddy@16 19 const (
paddy@16 20 // MinDeviceNameLength is the minimum length a Device name can be.
paddy@16 21 MinDeviceNameLength = 1
paddy@16 22 // MaxDeviceNameLength is the maximum length a Device name can be.
paddy@16 23 MaxDeviceNameLength = 64
paddy@16 24 )
paddy@16 25
paddy@0 26 // Device represents a specific device that updates can be pushed to.
paddy@0 27 type Device struct {
paddy@0 28 ID uuid.ID
paddy@0 29 Name string
paddy@0 30 Owner uuid.ID
paddy@0 31 Type DeviceType
paddy@0 32 Created time.Time
paddy@0 33 LastSeen time.Time
paddy@0 34 PushToken string
paddy@0 35 }
paddy@0 36
paddy@0 37 // ApplyChange returns a Device that is a copy of the passed Device,
paddy@0 38 // but with the passed DeviceChange applied.
paddy@0 39 func ApplyChange(d Device, change DeviceChange) Device {
paddy@0 40 result := d
paddy@0 41 if change.Name != nil {
paddy@0 42 result.Name = *change.Name
paddy@0 43 }
paddy@0 44 if change.Owner != nil {
paddy@0 45 result.Owner = *change.Owner
paddy@0 46 } else {
paddy@0 47 // We don't want to accidentally leave a slice that
paddy@0 48 // is owned by both behind.
paddy@0 49 result.Owner = d.Owner.Copy()
paddy@0 50 }
paddy@0 51 if change.Type != nil {
paddy@0 52 result.Type = *change.Type
paddy@0 53 }
paddy@0 54 if change.LastSeen != nil {
paddy@0 55 result.LastSeen = *change.LastSeen
paddy@0 56 }
paddy@0 57 if change.PushToken != nil {
paddy@0 58 result.PushToken = *change.PushToken
paddy@0 59 }
paddy@0 60 return result
paddy@0 61 }
paddy@0 62
paddy@0 63 // DeviceChange represents a set of changes to a Device that will be used
paddy@0 64 // to update a Device.
paddy@0 65 type DeviceChange struct {
paddy@0 66 DeviceID uuid.ID
paddy@0 67 Name *string
paddy@0 68 Owner *uuid.ID
paddy@0 69 Type *DeviceType
paddy@0 70 LastSeen *time.Time
paddy@0 71 PushToken *string
paddy@0 72 }
paddy@0 73
paddy@0 74 // Storer is an interface to control how data is stored in and retrieved from
paddy@0 75 // the datastore.
paddy@0 76 type Storer interface {
paddy@0 77 GetDevices(ids []uuid.ID, c context.Context) (map[string]Device, error)
paddy@0 78 UpdateDevice(change DeviceChange, c context.Context) error
paddy@0 79 DeleteDevices(ids []uuid.ID, c context.Context) error
paddy@0 80 CreateDevices(devices []Device, c context.Context) error
paddy@0 81 ListDevicesByOwner(user uuid.ID, c context.Context) ([]Device, error)
paddy@0 82 }
paddy@0 83
paddy@12 84 // ErrDeviceAlreadyExists is returned when a Device is added to a Storer, but a
paddy@12 85 // Device with the same ID already exists in the Storer. The ID underlying
paddy@12 86 // ErrDeviceAlreadyExists will hold the ID that already exists.
paddy@5 87 type ErrDeviceAlreadyExists uuid.ID
paddy@5 88
paddy@5 89 func (e ErrDeviceAlreadyExists) Error() string {
paddy@5 90 return fmt.Sprintf("device with ID %s already exists in datastore", uuid.ID(e).String())
paddy@5 91 }
paddy@5 92
paddy@0 93 // GetMany returns as many of the Devices specified by the passed IDs as possible.
paddy@0 94 // They are returned as a map, with the key being the string version of the ID.
paddy@0 95 // No error will be returned if a Device can't be found.
paddy@0 96 func GetMany(ids []uuid.ID, c context.Context) (map[string]Device, error) {
paddy@0 97 results := map[string]Device{}
paddy@15 98 storer, err := GetStorer(c)
paddy@0 99 if err != nil {
paddy@0 100 log.Printf("Error retrieving Storer: %+v\n", err)
paddy@0 101 return results, err
paddy@0 102 }
paddy@0 103 results, err = storer.GetDevices(ids, c)
paddy@0 104 if err != nil {
paddy@0 105 log.Printf("Error retrieving Devices from %T: %+v\n", storer, err)
paddy@0 106 return results, err
paddy@0 107 }
paddy@0 108 return results, nil
paddy@0 109 }
paddy@0 110
paddy@0 111 // Get returns the Device specified by the passed ID. If the Device can't be found,
paddy@0 112 // an ErrDeviceNotFound error is returned.
paddy@0 113 func Get(id uuid.ID, c context.Context) (Device, error) {
paddy@0 114 results, err := GetMany([]uuid.ID{id}, c)
paddy@0 115 if err != nil {
paddy@0 116 return Device{}, err
paddy@0 117 }
paddy@0 118 result, ok := results[id.String()]
paddy@0 119 if !ok {
paddy@0 120 return Device{}, ErrDeviceNotFound
paddy@0 121 }
paddy@0 122 return result, nil
paddy@0 123 }
paddy@0 124
paddy@0 125 // Update applies the DeviceChange to the passed Device, and returns the result. If
paddy@0 126 // the Device can't be found, an ErrDeviceNotFound error was returned.
paddy@0 127 func Update(device Device, change DeviceChange, c context.Context) (Device, error) {
paddy@15 128 storer, err := GetStorer(c)
paddy@0 129 if err != nil {
paddy@0 130 log.Printf("Error retrieving Storer: %+v\n", err)
paddy@0 131 return Device{}, err
paddy@0 132 }
paddy@0 133 change.DeviceID = device.ID
paddy@0 134 err = storer.UpdateDevice(change, c)
paddy@0 135 if err != nil {
paddy@0 136 return Device{}, err
paddy@0 137 }
paddy@0 138 return ApplyChange(device, change), nil
paddy@0 139 }
paddy@0 140
paddy@0 141 // DeleteMany removes the passed IDs from the datastore. No error is returned if the
paddy@0 142 // ID doesn't correspond to a Device in the datastore.
paddy@0 143 func DeleteMany(ids []uuid.ID, c context.Context) error {
paddy@15 144 storer, err := GetStorer(c)
paddy@0 145 if err != nil {
paddy@0 146 log.Printf("Error retrieving Storer: %+v\n", err)
paddy@0 147 return err
paddy@0 148 }
paddy@0 149 return storer.DeleteDevices(ids, c)
paddy@0 150 }
paddy@0 151
paddy@0 152 // Delete removes the passed ID from the datastore. No error is returned if the ID doesn't
paddy@0 153 // correspond to a Device in the datastore.
paddy@0 154 func Delete(id uuid.ID, c context.Context) error {
paddy@0 155 return DeleteMany([]uuid.ID{id}, c)
paddy@0 156 }
paddy@0 157
paddy@0 158 // CreateMany stores the passed Devices in the datastore, assigning default values if
paddy@0 159 // necessary. The Devices that were ultimately stored (including any default values, if
paddy@0 160 // applicable) are returned.
paddy@0 161 func CreateMany(devices []Device, c context.Context) ([]Device, error) {
paddy@15 162 storer, err := GetStorer(c)
paddy@0 163 if err != nil {
paddy@0 164 log.Printf("Error retrieving Storer: %+v\n", err)
paddy@0 165 return []Device{}, err
paddy@0 166 }
paddy@0 167 modified := make([]Device, 0, len(devices))
paddy@0 168 for _, device := range devices {
paddy@0 169 if device.ID.IsZero() {
paddy@0 170 device.ID = uuid.NewID()
paddy@0 171 }
paddy@0 172 if device.Created.IsZero() {
paddy@0 173 device.Created = time.Now()
paddy@0 174 }
paddy@0 175 if device.LastSeen.IsZero() {
paddy@0 176 device.LastSeen = time.Now()
paddy@0 177 }
paddy@0 178 modified = append(modified, device)
paddy@0 179 }
paddy@15 180 err = storer.CreateDevices(modified, c)
paddy@0 181 if err != nil {
paddy@0 182 return []Device{}, err
paddy@0 183 }
paddy@0 184 return modified, nil
paddy@0 185 }
paddy@0 186
paddy@0 187 // Create stores the passed Device in the datastore, assigning default values if
paddy@0 188 // necessary. The Devices that were ultimately stored (including any default values, if
paddy@0 189 // applicable) are returned.
paddy@0 190 func Create(device Device, c context.Context) (Device, error) {
paddy@0 191 devices, err := CreateMany([]Device{device}, c)
paddy@0 192 if err != nil {
paddy@0 193 return Device{}, err
paddy@0 194 }
paddy@0 195 // There should never be a case where we don't return a result.
paddy@0 196 // Ideally, we'd return an error here instead of letting the panic
paddy@0 197 // happen, but seeing as I can't come up with a reason the error would
paddy@0 198 // occur, I'm having trouble coming up with a reasonable error to return.
paddy@0 199 return devices[0], nil
paddy@0 200 }
paddy@0 201
paddy@0 202 // ListByOwner returns a slice of all the Devices with an Owner property that
paddy@0 203 // matches the passed ID. There's no guarantee on the order the Devices will be
paddy@0 204 // returned in.
paddy@0 205 func ListByOwner(user uuid.ID, c context.Context) ([]Device, error) {
paddy@0 206 // BUG(paddy): Eventually, we'll need to support paging for devices. But right now, I don't foresee any user creating enough of them to make pagination worthwhile.
paddy@15 207 storer, err := GetStorer(c)
paddy@0 208 if err != nil {
paddy@0 209 log.Printf("Error retrieving Storer: %+v\n", err)
paddy@0 210 return []Device{}, err
paddy@0 211 }
paddy@0 212 devices, err := storer.ListDevicesByOwner(user, c)
paddy@0 213 return devices, err
paddy@0 214 }
paddy@7 215
paddy@12 216 // ToMap transforms the passed slice into a map by using the String method of
paddy@12 217 // each Device's ID as the key, and the Device as the value.
paddy@7 218 func ToMap(devices []Device) map[string]Device {
paddy@7 219 results := make(map[string]Device, len(devices))
paddy@7 220 for _, device := range devices {
paddy@7 221 results[device.ID.String()] = device
paddy@7 222 }
paddy@7 223 return results
paddy@7 224 }
paddy@7 225
paddy@12 226 // ToSlice transforms the passed map of Devices into a slice of Devices.
paddy@7 227 func ToSlice(devices map[string]Device) []Device {
paddy@7 228 results := make([]Device, 0, len(devices))
paddy@7 229 for _, device := range devices {
paddy@7 230 results = append(results, device)
paddy@7 231 }
paddy@7 232 return results
paddy@7 233 }