Umbrellas

bench/dispatch-performance.js

@@ -7,6 +7,7 @@
  * gut check of "are we fast yet?"
  */
 
+import History   from '../src/history'
 import Microcosm from '../src/microcosm'
 import time      from 'microtime'
 
@@ -15,6 +16,17 @@ const SAMPLES = 5
 
 console.log('\nConducting dispatch benchmark...\n')
 
+const action = n => n
+
+const Domain = {
+  getInitialState: () => 0,
+  register() {
+    return {
+      [action]: (n) => n + 1
+    }
+  }
+}
+
 var results = SIZES.map(function (SIZE) {
   /**
    * Force garbage collection. This is exposed by invoking
@@ -23,20 +35,19 @@ var results = SIZES.map(function (SIZE) {
    */
   global.gc()
 
-  var repo = new Microcosm({ maxHistory: Infinity })
-
-  var action = function test () {}
-  action.toString = function () { return 'test' }
+  /**
+   * Step 1. Build a history tree before making a Microcosm,
+   * this lets us isolate history building so we can specifically
+   * profile the dispatch process
+   */
+  var history = new History({ limit: Infinity })
 
-  var Domain = {
-    getInitialState: () => 0,
-    register() {
-      return {
-        test: (n) => n + 1
-      }
-    }
+  for (var i = 0; i < SIZE; i++) {
+    history.append(action).close(true)
   }
 
+  var repo = new Microcosm({ history })
+
   /**
    * Add the domain at multiple keys. This is a better simulation of actual
    * applications. Otherwise, efficiencies are obtained enumerating over
@@ -48,18 +59,6 @@ var results = SIZES.map(function (SIZE) {
   repo.addDomain('four',  Domain)
   repo.addDomain('five',  Domain)
 
-  /**
-   * Append a given number of actions into history. We use this method
-   * instead of `::push()` for benchmark setup performance. At the time of writing,
-   * `push` takes anywhere from 0.5ms to 15ms depending on the sample range.
-   * This adds up to a very slow boot time!
-   */
-  var startMemory = process.memoryUsage().heapUsed
-  for (var i = 0; i < SIZE; i++) {
-    repo.history.append(action).close(true)
-  }
-  var endMemory = process.memoryUsage().heapUsed
-
   /**
    * Warm up `::push()`
    * This gives V8 time to analyze the types for the code.
@@ -78,8 +77,7 @@ var results = SIZES.map(function (SIZE) {
 
   return {
     'Actions'      : SIZE.toLocaleString(),
-    'Rollforward'  : average.toLocaleString() + 'ms',
-    'Memory Usage' : ((endMemory - startMemory) / 1000000).toFixed(2) + 'mbs'
+    'Rollforward'  : average.toLocaleString() + 'ms'
   }
 })
 

bench/history-performance.js

@@ -25,9 +25,9 @@ const results = SIZES.map(function (SIZE) {
    */
   global.gc()
 
-  var action = () => {}
-  var stats  = { build: 0, root: 0, merge: 0, size: 0, prune: 0, memory: 0 }
-  var history   = new History()
+  var action  = () => {}
+  var stats   = { build: 0, root: 0, merge: 0, size: 0, prune: 0, memory: 0 }
+  var history = new History()
 
   var memoryBefore = process.memoryUsage().heapUsed
 
@@ -45,7 +45,7 @@ const results = SIZES.map(function (SIZE) {
    * the current branch.
    */
   now = time.now()
-  history.size()
+  history.setSize()
   stats.size = (time.now() - now) / 1000
 
   /**
@@ -67,18 +67,16 @@ const results = SIZES.map(function (SIZE) {
   }, {})
   stats.merge = (time.now() - now) / 1000
 
+  var memoryUsage = process.memoryUsage().heapUsed - memoryBefore
 
   /**
    * Measure time to dispose all nodes in the history. This also has
    * the side effect of helping to test memory leakage later.
    */
   now = time.now()
-  history.prune(function() {
-    return true
-  })
+  history.toArray().reverse().forEach(a => a.close())
   stats.prune = (time.now() - now) / 1000
 
-
   /**
    * Now that the history has been pruned, force garbage collection
    * and record the increase in heap usage.
@@ -93,8 +91,9 @@ const results = SIZES.map(function (SIZE) {
     '::append()': stats.build.toFixed(2) + 'ms',
     '::toArray()': stats.toArray.toFixed(4) + 'ms',
     '::reduce(merge)': stats.merge.toFixed(2) + 'ms',
-    '::size()': stats.size.toFixed(2) + 'ms',
+    '::setSize()': stats.size.toFixed(2) + 'ms',
     '::prune()': stats.prune.toFixed(2) + 'ms',
+    'Memory': (memoryUsage / 1000000).toFixed(3) + 'mbs',
     'Memory Growth': stats.memory.toFixed(3) + '%'
   }
 })

package.json

@@ -69,7 +69,7 @@
     "immutable": "3.8.1",
     "jsdom": "9.5.0",
     "json-loader": "0.5.4",
-    "microcosm-debugger": "vigetlabs/microcosm-debugger",
+    "microcosm-debugger": "git+ssh://git@github.com/vigetlabs/microcosm-debugger.git",
     "microtime": "2.1.1",
     "nyc": "8.3.0",
     "react": "~15.3.2",

src/action.js

@@ -16,16 +16,16 @@ export default class Action extends Emitter {
   /**
    * @param {Function} behavior - how the action should resolve.
    */
-  constructor (behavior) {
+  constructor (behavior, history) {
     super()
 
-    this.depth = 0
-    this.behavior = tag(behavior)
+    this.type = null
     this.payload = null
+    this.behavior = tag(behavior)
+    this.history = history
+    this.state = States.disabled
     this.parent = null
     this.sibling = null
-    this.state = States.disabled
-    this.type = null
   }
 
   /**
@@ -73,8 +73,8 @@ export default class Action extends Emitter {
    * @private
    * @return {Action} self
    */
-  execute (/** params **/) {
-    coroutine(this, this.behavior.apply(this, arguments))
+  execute (params) {
+    coroutine(this, this.behavior.apply(this, params))
 
     return this
   }
@@ -94,7 +94,9 @@ export default class Action extends Emitter {
       this.payload = payload
     }
 
-    this._emit('change', this.payload)
+    if (this.history) {
+      this.history.reconcile()
+    }
 
     return this
   }

src/addons/presenter.js

@@ -19,12 +19,10 @@ export default class Presenter extends Component {
     this.pure = this._getRepoPurity(this.repo, this.props)
 
     this._updatePropMap(this.props)
+
     this.state = this._getState()
 
-    if (this.repo) {
-      this._listener = () => this._updateState()
-      this.repo.on('change', this._listener)
-    }
+    this.repo.on('change', this._updateState, this)
   }
 
   getChildContext () {
@@ -58,7 +56,7 @@ export default class Presenter extends Component {
   }
 
   /**
-   * Teardown subscriptions and other behavior.
+   * Opposite of setup. Useful for cleaning up side-effects.
    *
    * @param {Microcosm} repo - The presenter's Microcosm instance
    * @param {Object} props - The presenter's props
@@ -67,10 +65,8 @@ export default class Presenter extends Component {
     // NOOP
   }
 
-  unsubscribe() {
-    if (this.repo) {
-      this.repo.off('change', this._listener)
-    }
+  shouldComponentUpdate (props, state) {
+    return !this.pure || !shallowEqual(state, this.state) || !shallowEqual(props, this.props)
   }
 
   componentWillMount() {
@@ -79,12 +75,13 @@ export default class Presenter extends Component {
 
   componentWillUnmount () {
     this.teardown(this.repo, this.props)
-    this.unsubscribe()
+    this.repo.teardown()
   }
 
   componentWillReceiveProps (nextProps) {
     if (this.pure === false || shallowEqual(nextProps, this.props) === false) {
       this._updatePropMap(nextProps)
+
       this.update(this.repo, nextProps)
     }
 
@@ -123,9 +120,9 @@ export default class Presenter extends Component {
    * @private
    */
   _updatePropMap (props) {
-    this.propMap = this.viewModel ? this.viewModel(props) : {}
+    this.propMap = this.viewModel(props)
 
-    if (this.repo && this.propMap === this.repo.state) {
+    if (this.propMap === this.repo.state) {
       console.warn("The view model for this presenter returned repo.state. " +
                    "This method onlys run when a presenter is given new properties. " +
                    "If you would like to subscribe to all state changes, return a " +
@@ -148,7 +145,7 @@ export default class Presenter extends Component {
    * @private
    */
   _getState () {
-    const repoState = this._getRepoState()
+    const repoState = this.repo.state
 
     if (typeof this.propMap === 'function') {
       return this.propMap(repoState)
@@ -169,14 +166,9 @@ export default class Presenter extends Component {
    * @private
    */
   _getRepo() {
-    return this.props.repo || this.context.repo
-  }
+    const repo = this.props.repo || this.context.repo
 
-  /**
-   * @private
-   */
-  _getRepoState() {
-    return this.repo ? this.repo.state : {}
+    return repo ? repo.fork() : new Microcosm()
   }
 
   /**

src/domain.js

@@ -8,6 +8,10 @@ const EMPTY = {}
 
 export default class Domain {
 
+  constructor() {
+    this.setup()
+  }
+
   /**
    * Setup runs right after a domain is added to a Microcosm, but before
    * it rebases state to include the domain's `getInitialState` value. This
@@ -20,8 +24,11 @@ export default class Domain {
   /**
    * A default register function that just returns an empty object. This helps
    * keep other code from branching.
+   *
+   * @param {string} type - The action type to respond to
+   * @return {object} a mapping of registrations
    */
-  register () {
+  register (type) {
     // NOOP
     return EMPTY
   }

src/domains/meta.js

@@ -1,11 +1,20 @@
 /**
  * Meta Domain
- * A domain for managing lifecycle methods and other
- * default behavior for other domains.
+ * A domain for managing lifecycle methods and other default behavior
+ * for other domains.
  */
 
 import lifecycle from '../lifecycle'
+import merge from '../merge'
 
 export default {
-  [lifecycle.willReset]: (_, next) => next
+
+  [lifecycle.willReset](_old, next) {
+    return next
+  },
+
+  [lifecycle.willReplace](old, next) {
+    return merge({}, old, next)
+  }
+
 }