fix(loki): fix binary index in batch updates when not cloning (#78)

Batch updates will now temporarily disable adaptive indices (when not cloning) for the duration of the batch update if binary indices are defined.  We will do a full lazy rebuild when batch update completes and re-enable adaptive indices.  This fixes edge case where binary indices could become corrupt.  If your batches are small or medium sized it will likely be faster to update docs individually, as they are modified instead.

See techfort/LokiJS@0178e9d

Author: Viatorus

packages/loki/spec/generic/binaryidx.spec.ts

@@ -323,6 +323,54 @@ describe("binary indices", () => {
     });
   });
 
+  describe("adaptiveBinaryIndex batch updates work", () => {
+    it("works", function() {
+      const db = new Loki("idxtest");
+      const items = db.addCollection<{a: number, b:boolean}>("items", {
+        adaptiveBinaryIndices: true,
+        indices: ["b"]
+      });
+
+      // init 4 docs with bool 'b' all false
+      const docs = [{a:8000, b:false}, {a:6000, b:false}, {a:4000, b: false}, {a:2000, b:false}];
+
+      items.insert(docs);
+
+      // update two docs to have 'b' true
+      let results = items.find({a: {$in: [8000, 6000]}});
+      results.forEach(function(obj) {
+        obj.b = true;
+      });
+      items.update(results);
+
+      // should be 2 of each
+      expect(items.find({b: true}).length).toEqual(2);
+      expect(items.find({b: false}).length).toEqual(2);
+
+      // reset all bool 'b' props to false
+      results = items.find({b: true});
+      results.forEach(function(obj) {
+        obj.b = false;
+      });
+      items.update(results);
+
+      // should be no true and 4 false
+      expect(items.find({b: true}).length).toEqual(0);
+      expect(items.find({b: false}).length).toEqual(4);
+
+      // update different 2 to be true
+      results = items.find({a: {$in: [8000, 2000]}});
+      results.forEach(function(obj) {
+        obj.b = true;
+      });
+      items.update(results);
+
+      // should be 2 true and 2 false
+      expect(items.find({b: true}).length).toEqual(2);
+      expect(items.find({b: false}).length).toEqual(2);
+    });
+  });
+
   describe("adaptiveBinaryIndexRemove works", () => {
     it("works", () => {
 

packages/loki/src/collection.ts

@@ -831,14 +831,27 @@ export class Collection<TData extends object = object, TNested extends object =
    */
   public update(doc: Doc<TData> | Doc<TData>[]): void {
     if (Array.isArray(doc)) {
-      let k = 0;
-      const len = doc.length;
-      for (k; k < len; k++) {
-        this.update(doc[k]);
+
+      // If not cloning, disable adaptive binary indices for the duration of the batch update,
+      // followed by lazy rebuild and re-enabling adaptive indices after batch update.
+      const adaptiveBatchOverride = !this.cloneObjects && this.adaptiveBinaryIndices
+        && Object.keys(this.binaryIndices).length > 0;
+      if (adaptiveBatchOverride) {
+        this.adaptiveBinaryIndices = false;
       }
+
+      for (let i = 0; i < doc.length; i++) {
+        this.update(doc[i]);
+      }
+
+      if (adaptiveBatchOverride) {
+        this.ensureAllIndexes();
+        this.adaptiveBinaryIndices = true;
+      }
+
       return;
     }
-    // verify object is a properly formed document
+    // Verify object is a properly formed document.
     if (doc.$loki === undefined) {
       throw new Error("Trying to update unsynced document. Please save the document first by using insert() or addMany()");
     }