From aa2c1335ac379a2223e55ef9696c3d67c23e160f Mon Sep 17 00:00:00 2001
From: Pablo Gamito <pablogamito@google.com>
Date: Wed, 20 May 2020 16:50:15 +0100
Subject: [PATCH] Implement diff transformation for properties

Test: N/A
Change-Id: Ib231e617db3d87fe1abe20e95137d9af17572d19
---
 tools/winscope/src/TraceView.vue |  88 +++++++++++++--
 tools/winscope/src/TreeView.vue  |  25 ++++-
 tools/winscope/src/transform.js  | 181 +++++++++++++++++++++++++------
 tools/winscope/src/utils/diff.js |  10 ++
 4 files changed, 258 insertions(+), 46 deletions(-)
 create mode 100644 tools/winscope/src/utils/diff.js

diff --git a/tools/winscope/src/TraceView.vue b/tools/winscope/src/TraceView.vue
index af58c0a60..d35c45537 100644
--- a/tools/winscope/src/TraceView.vue
+++ b/tools/winscope/src/TraceView.vue
@@ -45,6 +45,7 @@
       <md-content md-tag="md-toolbar" md-elevation="0" class="card-toolbar md-transparent md-dense">
         <h2 class="md-title" style="flex: 1">Properties</h2>
         <div class="filter">
+          <md-checkbox v-model="showPropertiesDiff">Show Diff</md-checkbox>
           <input id="filter" type="search" placeholder="Filter..." v-model="propertyFilterString" />
         </div>
       </md-content>
@@ -63,7 +64,7 @@ import TreeView from './TreeView.vue'
 import Timeline from './Timeline.vue'
 import Rects from './Rects.vue'
 
-import { transform_json } from './transform.js'
+import { ObjectTransformer } from './transform.js'
 import { format_transform_type, is_simple_transform } from './matrix_utils.js'
 import { DATA_TYPES } from './decode.js'
 import { stableIdCompatibilityFixup } from './utils/utils.js'
@@ -105,6 +106,25 @@ function formatProto(obj) {
   }
 }
 
+function findEntryInTree(tree, id) {
+  if (tree.stableId === id) {
+    return tree;
+  }
+
+  if (!tree.children) {
+    return null;
+  }
+
+  for (const child of tree.children) {
+    const foundEntry = findEntryInTree(child, id);
+    if (foundEntry) {
+      return foundEntry;
+    }
+  }
+
+  return null;
+}
+
 export default {
   name: 'traceview',
   data() {
@@ -118,24 +138,34 @@ export default {
       rects: [],
       tree: null,
       highlight: null,
+      showPropertiesDiff: false,
     }
   },
   methods: {
     itemSelected(item) {
       this.hierarchySelected = item;
-      this.selectedTree = transform_json(
-        item.obj,
-        item.name,
-        stableIdCompatibilityFixup(item),
-        {
-          skip: item.skip,
-          formatter: formatProto
-        },
-      );
+      this.selectedTree = this.getTransformedProperties(item);
       this.highlight = item.highlight;
       this.lastSelectedStableId = item.stableId;
       this.$emit('focus');
     },
+    getTransformedProperties(item) {
+      const transformer = new ObjectTransformer(
+        item.obj,
+        item.name,
+        stableIdCompatibilityFixup(item)
+      ).setOptions({
+          skip: item.skip,
+          formatter: formatProto,
+        });
+
+      if (this.showPropertiesDiff) {
+        const prevItem = this.getItemFromPrevTree(item);
+        transformer.withDiff(prevItem?.obj);
+      }
+
+      return transformer.transform();
+    },
     onRectClick(item) {
       if (item) {
         this.itemSelected(item);
@@ -178,6 +208,39 @@ export default {
     arrowDown() {
       return this.$refs.hierarchy.selectNext();
     },
+    getDataWithOffset(offset) {
+      const index = this.file.selectedIndex + offset;
+
+      if (index < 0 || index >= this.file.data.length) {
+        return null;
+      }
+
+      return this.file.data[index];
+    },
+    getItemFromPrevTree(entry) {
+      if (!this.showPropertiesDiff || !this.hierarchySelected) {
+        return null;
+      }
+
+      const id = entry.stableId;
+      if (!id) {
+        throw new Error("Entry has no stableId...");
+      }
+
+      const prevTree = this.getDataWithOffset(-1);
+      if (!prevTree) {
+        console.warn("No previous entry");
+        return null;
+      }
+
+      const prevEntry = findEntryInTree(prevTree, id);
+      if (!prevEntry) {
+        console.warn("Didn't exist in last entry");
+        // TODO: Maybe handle this in some way.
+      }
+
+      return prevEntry;
+    }
   },
   created() {
     this.setData(this.file.data[this.file.selectedIndex]);
@@ -185,6 +248,11 @@ export default {
   watch: {
     selectedIndex() {
       this.setData(this.file.data[this.file.selectedIndex]);
+    },
+    showPropertiesDiff() {
+      if (this.hierarchySelected) {
+        this.selectedTree = this.getTransformedProperties(this.hierarchySelected);
+      }
     }
   },
   props: ['store', 'file'],
diff --git a/tools/winscope/src/TreeView.vue b/tools/winscope/src/TreeView.vue
index 3dd528a0d..5a0402b6e 100644
--- a/tools/winscope/src/TreeView.vue
+++ b/tools/winscope/src/TreeView.vue
@@ -15,7 +15,7 @@
 <template>
   <div class="tree-view" v-if="item">
     <div class="node"
-      :class="{ leaf: isLeaf, selected: isSelected, clickable: isClickable }"
+      :class="{ leaf: isLeaf, selected: isSelected, clickable: isClickable, diffClass }"
       :style="nodeOffsetStyle"
       @click="clicked"
       ref="node"
@@ -76,6 +76,8 @@
 import jsonProtoDefs from "frameworks/base/core/proto/android/server/windowmanagertrace.proto";
 import protobuf from "protobufjs";
 
+import { DiffType } from "./utils/diff.js";
+
 var protoDefs = protobuf.Root.fromJSON(jsonProtoDefs);
 var TraceMessage = protoDefs.lookupType(
   "com.android.server.wm.WindowManagerTraceFileProto"
@@ -116,6 +118,12 @@ export default {
       clickTimeout: null,
       isCollapsedByDefault,
       localCollapsedState: isCollapsedByDefault,
+      diffSymbol: {
+        [DiffType.NONE]: "",
+        [DiffType.ADDED]: "+",
+        [DiffType.DELETED]: "-",
+        [DiffType.MODIFIED]: ".",
+      },
     };
   },
   methods: {
@@ -271,6 +279,9 @@ export default {
 
       return false;
     },
+    diffClass() {
+      return this.item.diff ? this.item.diff.type : ''
+    },
     chipClassOrDefault() {
       return this.chipClass || "tree-view-chip";
     },
@@ -335,6 +346,18 @@ export default {
   background: #f1f1f1;
 }
 
+.tree-view .node:not(.selected).added {
+  background: chartreuse;
+}
+
+.tree-view .node:not(.selected).removed {
+  background: coral;
+}
+
+.tree-view .node:not(.selected).modified {
+  background: cyan;
+}
+
 .children {
   /* Aligns border with collapse arrows */
   margin-left: 12px;
diff --git a/tools/winscope/src/transform.js b/tools/winscope/src/transform.js
index 32a2661a5..b2372b38a 100644
--- a/tools/winscope/src/transform.js
+++ b/tools/winscope/src/transform.js
@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+import { DiffType } from './utils/diff.js';
+
 // kind - a type used for categorization of different levels
 // name - name of the node
 // children - list of child entries. Each child entry is pair list [raw object, nested transform function].
@@ -92,47 +94,156 @@ function transform({ obj, kind, name, children, timestamp, rect, bounds, highlig
 	return Object.freeze(result);
 }
 
+function getDiff(val, compareVal) {
+	if (val && isTerminal(compareVal)) {
+		return { type: DiffType.ADDED };
+	} else if (isTerminal(val) && compareVal) {
+		return { type: DiffType.DELETED };
+	} else if (compareVal != val) {
+		return { type: DiffType.MODIFIED };
+	} else {
+		return { type: DiffType.NONE };
+	}
+}
 
-function transform_json(obj, name, stableId, options) {
-	let { skip, formatter } = options;
+// Represents termination of the object traversal,
+// differentiated with a null value in the object.
+class Terminal { }
 
-	var children = [];
-	var formatted = undefined;
+function isTerminal(obj) {
+	return obj instanceof Terminal;
+}
 
-	if (skip && skip.includes(obj)) {
-		// skip
-	} else if ((formatted = formatter(obj))) {
-		children.push(transform_json(null, formatted, `${stableId}.${formatted}`, options));
-	} else if (Array.isArray(obj)) {
-		obj.forEach((e, i) => {
-			children.push(transform_json(e, "" + i, `${stableId}[${i}]`, options));
-		})
-	} else if (typeof obj == 'string') {
-		children.push(transform_json(null, obj, `${stableId}.${obj}`, options));
-	} else if (typeof obj == 'number' || typeof obj == 'boolean') {
-		children.push(transform_json(null, "" + obj, `${stableId}.${obj}`, options));
-	} else if (obj && typeof obj == 'object') {
-		Object.keys(obj).forEach((key) => {
-			children.push(transform_json(obj[key], key, `${stableId}.${key}`, options));
-		});
+class ObjectTransformer {
+	constructor(obj, rootName, stableId) {
+		this.obj = obj;
+		this.rootName = rootName;
+		this.stableId = stableId;
+		this.diff = false;
 	}
 
-	if (children.length == 1 && !children[0].combined) {
-		return Object.freeze({
-			kind: "",
-			name: name + ": " + children[0].name,
-			stableId: stableId,
-			children: children[0].children,
-			combined: true
-		});
+	setOptions(options) {
+		this.options = options;
+		return this;
 	}
 
-	return Object.freeze({
-		kind: "",
-		name: name,
-		stableId: stableId,
-		children: children,
-	});
+	withDiff(obj) {
+		this.diff = true;
+		this.compareWithObj = obj ?? new Terminal();
+		return this;
+	}
+
+	transform() {
+		const { formatter } = this.options;
+		if (!formatter) {
+			throw new Error("Missing formatter, please set with setOptions()");
+		}
+
+		return this._transform(this.obj, this.rootName, this.compareWithObj, this.rootName, this.stableId);
+	}
+
+	_transformKeys(obj) {
+		const { skip, formatter } = this.options;
+		const transformedObj = {};
+		let formatted = undefined;
+
+		if (skip && skip.includes(obj)) {
+			// skip
+		} else if ((formatted = formatter(obj))) {
+			// Obj has been formatted into a terminal node — has no children.
+			transformedObj[formatted] = new Terminal();
+		} else if (Array.isArray(obj)) {
+			obj.forEach((e, i) => {
+				transformedObj["" + i] = e;
+			});
+		} else if (typeof obj == 'string') {
+			// Object is a primitive type — has no children. Set to terminal
+			// to differentiate between null object and Terminal element.
+			transformedObj[obj] = new Terminal();
+		} else if (typeof obj == 'number' || typeof obj == 'boolean') {
+			// Similar to above — primitive type node has no children.
+			transformedObj["" + obj] = new Terminal();
+		} else if (obj && typeof obj == 'object') {
+			Object.keys(obj).forEach((key) => {
+				transformedObj[key] = obj[key];
+			});
+		} else if (obj === null) {
+			// Null object is a has no children — set to be terminal node.
+			transformedObj.null = new Terminal();
+		}
+
+		return transformedObj;
+	}
+
+	_transform(obj, name, compareWithObj, compareWithName, stableId) {
+		const children = [];
+
+		if (!isTerminal(obj)) {
+			obj = this._transformKeys(obj);
+		}
+		if (!isTerminal(compareWithObj)) {
+			compareWithObj = this._transformKeys(compareWithObj);
+		}
+
+		for (const key in obj) {
+			if (obj.hasOwnProperty(key)) {
+				let compareWithChild = new Terminal();
+				let compareWithName = new Terminal();
+				if (compareWithObj.hasOwnProperty(key)) {
+					compareWithChild = compareWithObj[key];
+					compareWithName = key;
+				}
+				children.push(this._transform(obj[key], key, compareWithChild, compareWithName, `${stableId}.${key}`));
+			}
+		}
+
+		// Takes care of adding deleted items to final tree
+		for (const key in compareWithObj) {
+			if (!obj.hasOwnProperty(key) && compareWithObj.hasOwnProperty(key)) {
+				children.push(this._transform(new Terminal(), new Terminal(), compareWithObj[key], key));
+			}
+		}
+
+		let transformedObj;
+		if (
+			children.length == 1 &&
+			children[0].children.length == 0 &&
+			!children[0].combined
+		) {
+			// Merge leaf key value pairs.
+			const child = children[0];
+
+			transformedObj = {
+				kind: "",
+				name: name + ": " + child.name,
+				stableId: stableId,
+				children: child.children,
+				combined: true,
+			}
+
+			if (this.diff) {
+				transformedObj.diff = child.diff;
+			}
+		} else {
+			transformedObj = {
+				kind: "",
+				name,
+				stableId: stableId,
+				children,
+			};
+
+			if (this.diff) {
+				const diff = getDiff(name, compareWithName);
+				transformedObj.diff = diff;
+
+				if (diff.type == DiffType.DELETED) {
+					transformedObj.name = compareWithName;
+				}
+			}
+		}
+
+		return Object.freeze(transformedObj);
+	}
 }
 
 function nanos_to_string(elapsedRealtimeNanos) {
@@ -163,4 +274,4 @@ function get_visible_chip() {
 	return { short: 'V', long: "visible", class: 'default' };
 }
 
-export { transform, transform_json, nanos_to_string, get_visible_chip };
+export { transform, ObjectTransformer, nanos_to_string, get_visible_chip };
diff --git a/tools/winscope/src/utils/diff.js b/tools/winscope/src/utils/diff.js
new file mode 100644
index 000000000..4482f0367
--- /dev/null
+++ b/tools/winscope/src/utils/diff.js
@@ -0,0 +1,10 @@
+const DiffType = Object.freeze({
+    NONE: 'none',
+    ADDED: 'added',
+    DELETED: 'deleted',
+    ADDED_MOVE: 'addedMove',
+    DELETED_MOVE: 'deletedMove',
+    MODIFIED: 'modified',
+});
+
+export { DiffType };
\ No newline at end of file