Refactoring properties getters

controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/api/Device.kt

@@ -29,21 +29,25 @@ public interface Device : Closeable, ContextAware, CoroutineScope {
     public val actionDescriptors: Collection<ActionDescriptor>
 
     /**
-     * Get the value of the property or throw error if property in not defined.
+     * Read physical state of property and update/push notifications if needed.
-     * Suspend if property value is not available
      */
-    public suspend fun getProperty(propertyName: String): MetaItem
+    public suspend fun readItem(propertyName: String): MetaItem
 
     /**
-     * Invalidate property and force recalculate
+     * Get the logical state of property or return null if it is invalid
      */
-    public suspend fun invalidateProperty(propertyName: String)
+    public fun getItem(propertyName: String): MetaItem?
+
+    /**
+     * Invalidate property (set logical state to invalid)
+     */
+    public suspend fun invalidate(propertyName: String)
 
     /**
      * Set property [value] for a property with name [propertyName].
      * In rare cases could suspend if the [Device] supports command queue and it is full at the moment.
      */
-    public suspend fun setProperty(propertyName: String, value: MetaItem)
+    public suspend fun writeItem(propertyName: String, value: MetaItem)
 
     /**
      * The [SharedFlow] of property changes
@@ -65,9 +69,19 @@ public interface Device : Closeable, ContextAware, CoroutineScope {
     }
 }
 
-public suspend fun Device.getState(): Meta = Meta{
+
-    for(descriptor in propertyDescriptors) {
+/**
-        descriptor.name put getProperty(descriptor.name)
+ * Get the logical state of property or suspend to read the physical value.
+ */
+public suspend fun Device.getOrReadItem(propertyName: String): MetaItem =
+    getItem(propertyName) ?: readItem(propertyName)
+
+/**
+ * Get a snapshot of logical state of the device
+ */
+public fun Device.getProperties(): Meta = Meta {
+    for (descriptor in propertyDescriptors) {
+        descriptor.name put getItem(descriptor.name)
     }
 }
 

controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/api/DeviceHub.kt

@@ -58,11 +58,11 @@ public fun DeviceHub.getOrNull(nameString: String): Device? = getOrNull(nameStri
 public operator fun DeviceHub.get(nameString: String): Device =
     getOrNull(nameString) ?: error("Device with name $nameString not found in $this")
 
-public suspend fun DeviceHub.getProperty(deviceName: Name, propertyName: String): MetaItem =
+public suspend fun DeviceHub.readItem(deviceName: Name, propertyName: String): MetaItem =
-    this[deviceName].getProperty(propertyName)
+    this[deviceName].readItem(propertyName)
 
-public suspend fun DeviceHub.setProperty(deviceName: Name, propertyName: String, value: MetaItem) {
+public suspend fun DeviceHub.writeItem(deviceName: Name, propertyName: String, value: MetaItem) {
-    this[deviceName].setProperty(propertyName, value)
+    this[deviceName].writeItem(propertyName, value)
 }
 
 public suspend fun DeviceHub.execute(deviceName: Name, command: String, argument: MetaItem?): MetaItem? =

controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/base/DeviceBase.kt

@@ -152,14 +152,17 @@ public abstract class DeviceBase(final override val context: Context) : Device {
         _actions[name] = action
     }
 
-    override suspend fun getProperty(propertyName: String): MetaItem =
+    override suspend fun readItem(propertyName: String): MetaItem =
         (_properties[propertyName] ?: error("Property with name $propertyName not defined")).read()
 
-    override suspend fun invalidateProperty(propertyName: String) {
+    override fun getItem(propertyName: String): MetaItem?=
+        (_properties[propertyName] ?: error("Property with name $propertyName not defined")).value
+
+    override suspend fun invalidate(propertyName: String) {
         (_properties[propertyName] ?: error("Property with name $propertyName not defined")).invalidate()
     }
 
-    override suspend fun setProperty(propertyName: String, value: MetaItem) {
+    override suspend fun writeItem(propertyName: String, value: MetaItem) {
         (_properties[propertyName] as? DeviceProperty ?: error("Property with name $propertyName not defined")).write(
             value
         )

controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/controllers/DeviceController.kt

@@ -67,7 +67,7 @@ public class DeviceController(
                 is PropertyGetMessage -> {
                     PropertyChangedMessage(
                         property = request.property,
-                        value = device.getProperty(request.property),
+                        value = device.getOrReadItem(request.property),
                         sourceDevice = deviceTarget,
                         targetDevice = request.sourceDevice
                     )
@@ -75,13 +75,13 @@ public class DeviceController(
 
                 is PropertySetMessage -> {
                     if (request.value == null) {
-                        device.invalidateProperty(request.property)
+                        device.invalidate(request.property)
                     } else {
-                        device.setProperty(request.property, request.value)
+                        device.writeItem(request.property, request.value)
                     }
                     PropertyChangedMessage(
                         property = request.property,
-                        value = device.getProperty(request.property),
+                        value = device.getOrReadItem(request.property),
                         sourceDevice = deviceTarget,
                         targetDevice = request.sourceDevice
                     )

controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/properties/DeviceBySpec.kt

@@ -1,8 +1,10 @@
 package ru.mipt.npm.controls.properties
 
-import kotlinx.coroutines.*
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.SupervisorJob
 import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.SharedFlow
+import kotlinx.coroutines.launch
 import kotlinx.coroutines.sync.Mutex
 import kotlinx.coroutines.sync.withLock
 import ru.mipt.npm.controls.api.ActionDescriptor
@@ -21,6 +23,7 @@ import kotlin.reflect.KProperty
 /**
  * @param D recursive self-type for properties and actions
  */
+@OptIn(InternalDeviceAPI::class)
 public open class DeviceBySpec<D : DeviceBySpec<D>>(
     public val spec: DeviceSpec<D>,
     context: Context = Global,
@@ -55,11 +58,9 @@ public open class DeviceBySpec<D : DeviceBySpec<D>>(
     internal val self: D
         get() = this as D
 
-    internal fun getLogicalState(propertyName: String): MetaItem? = logicalState[propertyName]
-
     private val stateLock = Mutex()
 
-    internal suspend fun updateLogical(propertyName: String, value: MetaItem?) {
+    private suspend fun updateLogical(propertyName: String, value: MetaItem?) {
         if (value != logicalState[propertyName]) {
             stateLock.withLock {
                 logicalState[propertyName] = value
@@ -74,27 +75,26 @@ public open class DeviceBySpec<D : DeviceBySpec<D>>(
      * Force read physical value and push an update if it is changed. It does not matter if logical state is present.
      * The logical state is updated after read
      */
-    public suspend fun readProperty(propertyName: String): MetaItem {
+    override suspend fun readItem(propertyName: String): MetaItem {
         val newValue = properties[propertyName]?.readItem(self)
             ?: error("A property with name $propertyName is not registered in $this")
         updateLogical(propertyName, newValue)
         return newValue
     }
 
-    override suspend fun getProperty(propertyName: String): MetaItem =
+    override fun getItem(propertyName: String): MetaItem? = logicalState[propertyName]
-        logicalState[propertyName] ?: readProperty(propertyName)
 
-    override suspend fun invalidateProperty(propertyName: String) {
+    override suspend fun invalidate(propertyName: String) {
         stateLock.withLock {
             logicalState.remove(propertyName)
         }
     }
 
-    override suspend fun setProperty(propertyName: String, value: MetaItem): Unit {
+    override suspend fun writeItem(propertyName: String, value: MetaItem): Unit {
         //If there is a physical property with given name, invalidate logical property and write physical one
         (properties[propertyName] as? WritableDevicePropertySpec<D, out Any>)?.let {
             it.writeItem(self, value)
-            invalidateProperty(propertyName)
+            invalidate(propertyName)
         } ?: run {
             updateLogical(propertyName, value)
         }
@@ -113,36 +113,44 @@ public open class DeviceBySpec<D : DeviceBySpec<D>>(
     ): ReadWriteProperty<D, T> = observable(initialValue) { property: KProperty<*>, oldValue: T, newValue: T ->
         if (oldValue != newValue) {
             launch {
-                invalidateProperty(property.name)
+                invalidate(property.name)
                 _propertyFlow.emit(property.name to converter.objectToMetaItem(newValue))
             }
         }
     }
 
-    public suspend fun <T : Any> DevicePropertySpec<D, T>.read(): T = read(self)
+    /**
+     * Read typed value and update/push event if needed
+     */
+    public suspend fun <T : Any> DevicePropertySpec<D, T>.read(): T {
+        val res = read(self)
+        updateLogical(name, converter.objectToMetaItem(res))
+        return res
+    }
+
+    public fun <T : Any> DevicePropertySpec<D, T>.get(): T? = getItem(name)?.let(converter::itemToObject)
+
+    /**
+     * Write typed property state and invalidate logical state
+     */
+    public suspend fun <T : Any> WritableDevicePropertySpec<D, T>.write(value: T) {
+        write(self, value)
+        invalidate(name)
+    }
 
     override fun close() {
-        with(spec){ self.onShutdown() }
+        with(spec) { self.onShutdown() }
         super.close()
     }
 }
 
-public suspend fun <D : DeviceBySpec<D>, T : Any> D.getSuspend(
+public suspend fun <D : DeviceBySpec<D>, T : Any> D.read(
     propertySpec: DevicePropertySpec<D, T>
-): T = propertySpec.read(this@getSuspend).also {
+): T = propertySpec.read()
-    updateLogical(propertySpec.name, propertySpec.converter.objectToMetaItem(it))
+
+public fun <D : DeviceBySpec<D>, T : Any> D.write(
+    propertySpec: WritableDevicePropertySpec<D, T>,
+    value: T
+): Job = launch {
+    propertySpec.write(value)
 }
-
-
-public fun <D : DeviceBySpec<D>, T : Any> D.getAsync(
-    propertySpec: DevicePropertySpec<D, T>
-): Deferred<T> = async {
-    getSuspend(propertySpec)
-}
-
-public operator fun <D : DeviceBySpec<D>, T : Any> D.set(propertySpec: WritableDevicePropertySpec<D, T>, value: T) {
-    launch {
-        propertySpec.write(this@set, value)
-        invalidateProperty(propertySpec.name)
-    }
-}

controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/properties/DevicePropertySpec.kt

@@ -8,6 +8,13 @@ import space.kscience.dataforge.meta.transformations.MetaConverter
 import space.kscience.dataforge.meta.transformations.nullableItemToObject
 import space.kscience.dataforge.meta.transformations.nullableObjectToMetaItem
 
+
+/**
+ * This API is internal and should not be used in user code
+ */
+@RequiresOptIn
+public annotation class InternalDeviceAPI
+
 //TODO relax T restriction after DF 0.4.4
 public interface DevicePropertySpec<in D : Device, T : Any> {
     /**
@@ -28,9 +35,11 @@ public interface DevicePropertySpec<in D : Device, T : Any> {
     /**
      * Read physical value from the given [device]
      */
+    @InternalDeviceAPI
     public suspend fun read(device: D): T
 }
 
+@OptIn(InternalDeviceAPI::class)
 public suspend fun <D : Device, T : Any> DevicePropertySpec<D, T>.readItem(device: D): MetaItem =
     converter.objectToMetaItem(read(device))
 
@@ -39,9 +48,11 @@ public interface WritableDevicePropertySpec<in D : Device, T : Any> : DeviceProp
     /**
      * Write physical value to a device
      */
+    @InternalDeviceAPI
     public suspend fun write(device: D, value: T)
 }
 
+@OptIn(InternalDeviceAPI::class)
 public suspend fun <D : Device, T : Any> WritableDevicePropertySpec<D, T>.writeItem(device: D, item: MetaItem) {
     write(device, converter.itemToObject(item))
 }

controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/properties/DeviceSpec.kt

@@ -13,6 +13,7 @@ import kotlin.reflect.KMutableProperty1
 import kotlin.reflect.KProperty
 import kotlin.reflect.KProperty1
 
+@OptIn(InternalDeviceAPI::class)
 public abstract class DeviceSpec<D : DeviceBySpec<D>>(
     private val buildDevice: () -> D
 ) : Factory<D> {

controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/properties/deviceExtensions.kt

@@ -0,0 +1,32 @@
+package ru.mipt.npm.controls.properties
+
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.isActive
+import kotlinx.coroutines.launch
+import kotlin.time.Duration
+
+/**
+ * Perform a recurring asynchronous read action and return a flow of results.
+ * The flow is lazy so action is not performed unless flow is consumed.
+ * The flow uses called context. In order to call it on device context, use `flowOn(coroutineContext)`.
+ *
+ * The flow is canceled when the device scope is canceled
+ */
+public fun <D : DeviceBySpec<D>, R> D.readRecurring(interval: Duration, reader: suspend D.() -> R): Flow<R> = flow {
+    while (isActive) {
+        kotlinx.coroutines.delay(interval)
+        emit(reader())
+    }
+}
+
+/**
+ * Do a recurring task on a device. The task could
+ */
+public fun <D : DeviceBySpec<D>> D.doRecurring(interval: Duration, task: suspend D.() -> Unit): Job = launch {
+    while (isActive) {
+        kotlinx.coroutines.delay(interval)
+        task()
+    }
+}

controls-core/src/jvmMain/kotlin/ru/mipt/npm/controls/properties/getDeviceProperty.kt

@@ -1,13 +1,10 @@
 package ru.mipt.npm.controls.properties
 
 import kotlinx.coroutines.runBlocking
-import ru.mipt.npm.controls.api.PropertyDescriptor
-import space.kscience.dataforge.meta.transformations.MetaConverter
-import kotlin.reflect.KFunction
 
 /**
  * Blocking property get call
  */
 public operator fun <D : DeviceBySpec<D>, T : Any> D.get(
     propertySpec: DevicePropertySpec<D, T>
-): T = runBlocking { getAsync(propertySpec).await() }
+): T = runBlocking { read(propertySpec) }

controls-magix-client/src/commonMain/kotlin/ru/mipt/npm/controls/client/tangoMagix.kt

@@ -6,6 +6,7 @@ import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.launch
 import kotlinx.serialization.Serializable
 import ru.mipt.npm.controls.api.get
+import ru.mipt.npm.controls.api.getOrReadItem
 import ru.mipt.npm.controls.controllers.DeviceManager
 import ru.mipt.npm.magix.api.MagixEndpoint
 import ru.mipt.npm.magix.api.MagixMessage
@@ -83,7 +84,7 @@ public fun DeviceManager.launchTangoMagix(
                 val device = get(request.payload.device)
                 when (request.payload.action) {
                     TangoAction.read -> {
-                        val value = device.getProperty(request.payload.name)
+                        val value = device.getOrReadItem(request.payload.name)
                         respond(request) { requestPayload ->
                             requestPayload.copy(
                                 value = value,
@@ -93,10 +94,10 @@ public fun DeviceManager.launchTangoMagix(
                     }
                     TangoAction.write -> {
                         request.payload.value?.let { value ->
-                            device.setProperty(request.payload.name, value)
+                            device.writeItem(request.payload.name, value)
                         }
                         //wait for value to be written and return final state
-                        val value = device.getProperty(request.payload.name)
+                        val value = device.getOrReadItem(request.payload.name)
                         respond(request) { requestPayload ->
                             requestPayload.copy(
                                 value = value,

demo/src/main/kotlin/ru/mipt/npm/controls/demo/DemoDevice.kt

@@ -1,17 +1,16 @@
 package ru.mipt.npm.controls.demo
 
-import kotlinx.coroutines.delay
-import kotlinx.coroutines.isActive
-import kotlinx.coroutines.launch
 import ru.mipt.npm.controls.properties.*
 import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.meta.transformations.MetaConverter
 import java.time.Instant
+import kotlin.time.Duration
+import kotlin.time.ExperimentalTime
 
 
 class DemoDevice : DeviceBySpec<DemoDevice>(DemoDevice) {
     var timeScale by state(5000.0)
-    var sinScale by state( 1.0)
+    var sinScale by state(1.0)
     var cosScale by state(1.0)
 
     companion object : DeviceSpec<DemoDevice>(::DemoDevice) {
@@ -34,8 +33,8 @@ class DemoDevice : DeviceBySpec<DemoDevice>(DemoDevice) {
             Meta {
                 val time = Instant.now()
                 "time" put time.toEpochMilli()
-                "x" put getSuspend(sin)
+                "x" put read(sin)
-                "y" put getSuspend(cos)
+                "y" put read(cos)
             }
         }
 
@@ -46,13 +45,11 @@ class DemoDevice : DeviceBySpec<DemoDevice>(DemoDevice) {
             null
         }
 
+        @OptIn(ExperimentalTime::class)
         override fun DemoDevice.onStartup() {
-            launch {
+            doRecurring(Duration.milliseconds(50)){
-                while(isActive){
+                sin.read()
-                    delay(50)
+                cos.read()
-                    sin.read()
-                    cos.read()
-                }
             }
         }
     }