Merge pull request #1703 from kchadha/cloud-io

Cloud IO

src/blocks/scratch3_data.js

@@ -45,6 +45,10 @@ class Scratch3DataBlocks {
         const variable = util.target.lookupOrCreateVariable(
             args.VARIABLE.id, args.VARIABLE.name);
         variable.value = args.VALUE;
+
+        if (variable.isCloud) {
+            util.ioQuery('cloud', 'requestUpdateVariable', [variable.name, args.VALUE]);
+        }
     }
 
     changeVariableBy (args, util) {
@@ -52,7 +56,12 @@ class Scratch3DataBlocks {
             args.VARIABLE.id, args.VARIABLE.name);
         const castedValue = Cast.toNumber(variable.value);
         const dValue = Cast.toNumber(args.VALUE);
-        variable.value = castedValue + dValue;
+        const newValue = castedValue + dValue;
+        variable.value = newValue;
+
+        if (variable.isCloud) {
+            util.ioQuery('cloud', 'requestUpdateVariable', [variable.name, newValue]);
+        }
     }
 
     changeMonitorVisibility (id, visible) {

src/engine/runtime.js

@@ -17,6 +17,7 @@ const Variable = require('./variable');
 
 // Virtual I/O devices.
 const Clock = require('../io/clock');
+const Cloud = require('../io/cloud');
 const DeviceManager = require('../io/deviceManager');
 const Keyboard = require('../io/keyboard');
 const Mouse = require('../io/mouse');
@@ -262,6 +263,7 @@ class Runtime extends EventEmitter {
         /** @type {Object.<string, Object>} */
         this.ioDevices = {
             clock: new Clock(),
+            cloud: new Cloud(),
             deviceManager: new DeviceManager(),
             keyboard: new Keyboard(this),
             mouse: new Mouse(this),
@@ -1383,6 +1385,7 @@ class Runtime extends EventEmitter {
         this.targets.map(this.disposeTarget, this);
         this._monitorState = OrderedMap({});
         // @todo clear out extensions? turboMode? etc.
+        this.ioDevices.cloud.clear();
     }
 
     /**

src/io/cloud.js

@@ -0,0 +1,129 @@
+const Variable = require('../engine/variable');
+const log = require('../util/log');
+
+class Cloud {
+    /**
+     * @typedef updateVariable
+     * @param {string} name The name of the cloud variable to update on the server
+     * @param {(string | number)} value The value to update the cloud variable with.
+     */
+
+    /**
+     * A cloud data provider, responsible for managing the connection to the
+     * cloud data server and for posting data about cloud data activity to
+     * this IO device.
+     * @typedef {object} CloudProvider
+     * @property {updateVariable} updateVariable A function which sends a cloud variable
+     * update to the cloud data server.
+     * @property {Function} requestCloseConnection A function which closes
+     * the connection to the cloud data server.
+     */
+
+    /**
+     * Part of a cloud io data post indicating a cloud variable update.
+     * @typedef {object} VarUpdateData
+     * @property {string} name The name of the variable to update
+     * @property {(number | string)} value The scalar value to update the variable with
+     */
+
+    /**
+     * A cloud io data post message.
+     * @typedef {object} CloudIOData
+     * @property {VarUpdateData} varUpdate A {@link VarUpdateData} message indicating
+     * a cloud variable update
+     */
+
+
+    /**
+     * Cloud IO Device responsible for sending and receiving messages from
+     * cloud provider (mananging the cloud server connection) and interacting
+     * with cloud variables in the current project.
+     */
+    constructor () {
+        /**
+         * Reference to the cloud data provider, responsible for mananging
+         * the web socket connection to the cloud data server.
+         * @type {?CloudProvider}
+         */
+        this.provider = null;
+
+        /**
+         * Reference to the stage target which owns the cloud variables
+         * in the project.
+         * @type {?Target}
+         */
+        this.stage = null;
+    }
+
+    /**
+     * Set a reference to the cloud data provider.
+     * @param {CloudProvider} provider The cloud data provider
+     */
+    setProvider (provider) {
+        this.provider = provider;
+    }
+
+    /**
+     * Set a reference to the stage target which owns the
+     * cloud variables in the project.
+     * @param {Target} stage The stage target
+     */
+    setStage (stage) {
+        this.stage = stage;
+    }
+
+    /**
+     * Handle incoming data to this io device.
+     * @param {CloudIOData} data The {@link CloudIOData} object to process
+     */
+    postData (data) {
+        if (data.varUpdate) {
+            this.updateCloudVariable(data.varUpdate);
+        }
+    }
+
+    /**
+     * Request the cloud data provider to update the given variable with
+     * the given value. Does nothing if this io device does not have a provider set.
+     * @param {string} name The name of the variable to update
+     * @param {string | number} value The value to update the variable with
+     */
+    requestUpdateVariable (name, value) {
+        if (this.provider) {
+            this.provider.updateVariable(name, value);
+        }
+    }
+
+    /**
+     * Update a cloud variable in the runtime based on the message received
+     * from the cloud provider.
+     * @param {VarUpdateData} varUpdate A {@link VarUpdateData} object describing
+     * a cloud variable update received from the cloud data provider.
+     */
+    updateCloudVariable (varUpdate) {
+        const varName = varUpdate.name;
+
+        const variable = this.stage.lookupVariableByNameAndType(varName, Variable.SCALAR_TYPE);
+        if (!variable || !variable.isCloud) {
+            log.warn(`Received an update for a cloud variable that does not exist: ${varName}`);
+            return;
+        }
+
+        variable.value = varUpdate.value;
+    }
+
+    /**
+     * Request the cloud data provider to close the web socket connection and
+     * clear this io device of references to the cloud data provider and the
+     * stage.
+     */
+    clear () {
+        if (!this.provider) return;
+
+        this.provider.requestCloseConnection();
+        this.provider = null;
+        this.stage = null;
+    }
+}
+
+module.exports = Cloud;

src/virtual-machine.js

@@ -218,6 +218,10 @@ class VirtualMachine extends EventEmitter {
         this.runtime.ioDevices.video.setProvider(videoProvider);
     }
 
+    setCloudProvider (cloudProvider) {
+        this.runtime.ioDevices.cloud.setProvider(cloudProvider);
+    }
+
     /**
      * Tell the specified extension to scan for a peripheral.
      * @param {string} extensionId - the id of the extension.
@@ -463,6 +467,7 @@ class VirtualMachine extends EventEmitter {
             this.emitTargetsUpdate();
             this.emitWorkspaceUpdate();
             this.runtime.setEditingTarget(this.editingTarget);
+            this.runtime.ioDevices.cloud.setStage(this.runtime.getTargetForStage());
         });
     }
 

test/unit/io_cloud.js

@@ -0,0 +1,84 @@
+const test = require('tap').test;
+const Cloud = require('../../src/io/cloud');
+const Target = require('../../src/engine/target');
+const Variable = require('../../src/engine/variable');
+
+test('spec', t => {
+    const cloud = new Cloud();
+
+    t.type(cloud, 'object');
+    t.type(cloud.postData, 'function');
+    t.type(cloud.requestUpdateVariable, 'function');
+    t.type(cloud.updateCloudVariable, 'function');
+    t.type(cloud.setProvider, 'function');
+    t.type(cloud.setStage, 'function');
+    t.type(cloud.clear, 'function');
+    t.end();
+});
+
+test('stage and provider are null initially', t => {
+    const cloud = new Cloud();
+
+    t.strictEquals(cloud.provider, null);
+    t.strictEquals(cloud.stage, null);
+    t.end();
+});
+
+test('setProvider sets the provider', t => {
+    const cloud = new Cloud();
+
+    const provider = {
+        foo: 'a fake provider'
+    };
+
+    cloud.setProvider(provider);
+    t.strictEquals(cloud.provider, provider);
+
+    t.end();
+});
+
+test('postData updates the variable', t => {
+    const stage = new Target();
+    const fooVar = new Variable(
+        'a fake var id',
+        'foo',
+        Variable.SCALAR_TYPE,
+        true /* isCloud */
+    );
+    stage.variables[fooVar.id] = fooVar;
+
+    t.strictEquals(fooVar.value, 0);
+
+    const cloud = new Cloud();
+    cloud.setStage(stage);
+    cloud.postData({varUpdate: {
+        name: 'foo',
+        value: 3
+    }});
+    t.strictEquals(fooVar.value, 3);
+    t.end();
+});
+
+test('requestUpdateVariable calls provider\'s updateVariable function', t => {
+    let updateVariableCalled = false;
+    let mockVarName = '';
+    let mockVarValue = '';
+    const mockUpdateVariable = (name, value) => {
+        updateVariableCalled = true;
+        mockVarName = name;
+        mockVarValue = value;
+        return;
+    };
+
+    const provider = {
+        updateVariable: mockUpdateVariable
+    };
+
+    const cloud = new Cloud();
+    cloud.setProvider(provider);
+    cloud.requestUpdateVariable('foo', 3);
+    t.equals(updateVariableCalled, true);
+    t.strictEquals(mockVarName, 'foo');
+    t.strictEquals(mockVarValue, 3);
+    t.end();
+});