From 7cda770e4cf304522bbba3e90d3015e9583c463d Mon Sep 17 00:00:00 2001
From: Kevin Schaaf <kschaaf@google.com>
Date: Wed, 10 Apr 2019 17:11:13 -0700
Subject: [PATCH] [wip] Add additional topo-sort based algorithm.

---
 lib/mixins/property-effects.js | 121 +++++++++++++++++++++++++++++----
 1 file changed, 107 insertions(+), 14 deletions(-)

diff --git a/lib/mixins/property-effects.js b/lib/mixins/property-effects.js
index f946014a10..fc82d767db 100644
--- a/lib/mixins/property-effects.js
+++ b/lib/mixins/property-effects.js
@@ -415,18 +415,113 @@ function runReflectEffect(inst, property, props, oldProps, info) {
 function runComputedEffects(inst, changedProps, oldProps, hasPaths) {
   let computeEffects = inst[TYPES.COMPUTE];
   if (computeEffects) {
-    let inputProps = changedProps;
-    while (runEffects(inst, computeEffects, inputProps, oldProps, hasPaths)) {
+    if (orderedComputed == 2) {
+      dedupeId++;
+      const order = orderedComputedDeps(inst);
+      const queue = [];
+      for (let p in changedProps) {
+        addEffectsFor(p, computeEffects, queue, order, hasPaths);
+      }
+      let info;
+      while ((info = queue.shift())) {
+        if (runComputedEffect(inst, '', changedProps, oldProps, info, hasPaths)) {
+          addEffectsFor(info.methodInfo, computeEffects, queue, order, hasPaths);
+        }
+      }
       Object.assign(/** @type {!Object} */ (oldProps), inst.__dataOld);
       Object.assign(/** @type {!Object} */ (changedProps), inst.__dataPending);
-      inputProps = inst.__dataPending;
       inst.__dataPending = null;
-      if (orderedComputed) {
-        // Ensure all computed properties are de-duped against the same turn
-        dedupeId--;
+    } else {
+      let inputProps = changedProps;
+      while (runEffects(inst, computeEffects, inputProps, oldProps, hasPaths)) {
+        Object.assign(/** @type {!Object} */ (oldProps), inst.__dataOld);
+        Object.assign(/** @type {!Object} */ (changedProps), inst.__dataPending);
+        inputProps = inst.__dataPending;
+        inst.__dataPending = null;
+        if (orderedComputed) {
+          // Ensure all computed properties are de-duped against the same turn
+          dedupeId--;
+        }
+      }
+    }
+  }
+}
+
+const insertEffect = (info, effects, order) => {
+  let start = 0;
+  let end = effects.length - 1;
+  let idx = -1;
+  while (start <= end) {
+    const mid = (start + end) >> 1;
+    const cmp = order.get(effects[mid].methodInfo) - order.get(info.methodInfo);
+    if (cmp < 0) {
+      start = mid + 1;
+    } else if (cmp > 0) {
+      end = mid - 1;
+    } else {
+      idx = mid;
+      break;
+    }
+  }
+  if (idx < 0) {
+    idx = end + 1;
+  }
+  effects.splice(idx, 0, info);
+};
+
+const addEffectsFor = (prop, computeEffects, queue, order, hasPaths) => {
+  const rootProperty = hasPaths ? root(prop) : prop;
+  const fxs = computeEffects[rootProperty];
+  if (fxs) {
+    for (let i=0; i<fxs.length; i++) {
+      const fx = fxs[i];
+      if ((fx.info.lastRun !== dedupeId) &&
+          (!hasPaths || pathMatchesTrigger(prop, fx.trigger))) {
+        fx.info.lastRun = dedupeId;
+        insertEffect(fx.info, queue, order);
+      }
+    }
+  }
+};
+
+function orderedComputedDeps(inst) {
+  let ordered = inst.constructor.__orderedComputedDeps;
+  if (!ordered) {
+    ordered = new Map();
+    const effects = inst[TYPES.COMPUTE];
+    const {counts, next} = edgeCounts(inst);
+    let curr;
+    while ((curr = next.pop())) {
+      ordered.set(curr, ordered.size);
+      const computedByCurr = effects[curr];
+      if (computedByCurr) {
+        computedByCurr.forEach(fx => {
+          const p = fx.info.methodInfo;
+          if (--counts[p] === 0) {
+            next.push(p);
+          }
+        });
       }
     }
+    inst.constructor.__orderedComputedDeps = ordered;
+  }
+  return ordered;
+}
+
+function edgeCounts(inst) {
+  const props = inst.constructor._properties;
+  const depsForComputed = inst[COMPUTE_INFO];
+  const counts = {};
+  const next = [];
+  for (let p in props) {
+    const deps = depsForComputed[p];  
+    if (deps) { 
+      counts[p] = deps.args.length;
+    } else {
+      next.push(p);
+    }
   }
+  return {counts, next};
 }
 
 const TRANSITIVE_DEPENDENCY = '~transitive~dependency~';
@@ -442,11 +537,11 @@ const TRANSITIVE_DEPENDENCY = '~transitive~dependency~';
  * @param {?Object} oldProps Bag of previous values for changed properties
  * @param {?} info Effect metadata
  * @param {boolean} hasPaths True with `changedProps` contains one or more paths
- * @return {void}
+ * @return {boolean} True when the property being computed changed
  * @private
  */
 function runComputedEffect(inst, property, changedProps, oldProps, info, hasPaths) {
-  if (orderedComputed) {
+  if (orderedComputed == 1) {
     // Compute any computed dependencies first; this recurses through the
     // dependency graph to ensure computed properties are never computed with
     // dependencies that may become invalidated later in this turn
@@ -467,7 +562,7 @@ function runComputedEffect(inst, property, changedProps, oldProps, info, hasPath
   }
   let computedProp = info.methodInfo;
   if (inst.__dataHasAccessor && inst.__dataHasAccessor[computedProp]) {
-    inst._setPendingProperty(computedProp, result, true);
+    return inst._setPendingProperty(computedProp, result, true);
   } else {
     inst[computedProp] = result;
   }
@@ -2369,11 +2464,9 @@ export const PropertyEffects = dedupingMixin(superClass => {
         throw new Error("Malformed computed expression '" + expression + "'");
       }
       const info = createMethodEffect(this, sig, TYPES.COMPUTE, runComputedEffect, property, dynamicFn);
-      if (orderedComputed) {
-        // Effects are normally stored as map of dependency->effect, but for
-        // ordered computation, we also need tree of computedProp->dependencies 
-        ensureOwnEffectMap(this, COMPUTE_INFO)[property] = info;
-      }
+      // Effects are normally stored as map of dependency->effect, but for
+      // ordered computation, we also need tree of computedProp->dependencies 
+      ensureOwnEffectMap(this, COMPUTE_INFO)[property] = info;
     }
 
     /**