Initial version of transactions. Shell command implemented as an example. Still needs channel cleanup on app side, handling a device dying in the middle of a transaction, and getting device list back to normal.

res/app/components/stf/control/transaction-service.js

@@ -0,0 +1,124 @@
+var Promise = require('bluebird')
+
+module.exports = function TransactionServiceFactory(socket) {
+  var transactionService = {}
+
+  function createChannel() {
+    return 'tx' + Date.now() // @todo UUID
+  }
+
+  function Transaction(devices) {
+    var pending = Object.create(null)
+      , results = []
+      , channel = createChannel()
+      , resolver = Promise.defer()
+
+    function doneListener(someChannel, data) {
+      if (someChannel === channel) {
+        pending[data.serial].done(data)
+      }
+    }
+
+    function progressListener(someChannel, data) {
+      if (someChannel === channel) {
+        pending[data.serial].progress(data)
+      }
+    }
+
+    socket.on('tx.done', doneListener)
+    socket.on('tx.progress', progressListener)
+
+    this.channel = channel
+    this.results = results
+    this.promise = Promise.settle(devices.map(function(device) {
+        var pendingResult = new PendingTransactionResult(device)
+        pending[device.serial] = pendingResult
+        results.push(pendingResult.result)
+        return pendingResult.promise
+      }))
+      .finally(function() {
+        socket.removeListener('tx.done', doneListener)
+        socket.removeListener('tx.progress', progressListener)
+      })
+      .progressed(function() {
+        console.log('progressing')
+        return results
+      })
+      .then(function() {
+        return results
+      })
+  }
+
+  function PendingTransactionResult(device) {
+    var resolver = Promise.defer()
+      , result = new TransactionResult(device)
+      , seq = 0
+      , last = null
+      , error = null
+      , unplaced = []
+
+    resolver.promise.finally(function() {
+      result.settled = true
+    })
+
+    function readQueue() {
+      var message
+        , foundAny = false
+
+      while (message = unplaced[seq]) {
+        unplaced[seq] = void 0
+
+        if (seq === last) {
+          result.success = message.success
+
+          if (message.success) {
+            if (message.data) {
+              result.data[seq] = message.data
+            }
+          }
+          else {
+            result.error = message.data
+          }
+
+          resolver.resolve(result)
+          return
+        }
+
+        foundAny = true
+        result.data[seq++] = message.data
+      }
+
+      if (foundAny) {
+        resolver.progress(result)
+      }
+    }
+
+    this.progress = function(message) {
+      unplaced[message.seq] = message
+      readQueue()
+    }
+
+    this.done = function(message) {
+      last = message.seq
+      unplaced[message.seq] = message
+      readQueue()
+    }
+
+    this.result = result
+    this.promise = resolver.promise
+  }
+
+  function TransactionResult(device) {
+    this.device = device
+    this.settled = false
+    this.success = false
+    this.error = null
+    this.data = []
+  }
+
+  transactionService.create = function(devices) {
+    return new Transaction(devices)
+  }
+
+  return transactionService
+}