feat: add batch size to cursors

src/database/mongo/sorted/intersect.js

@@ -12,7 +12,7 @@ module.exports = function (module) {
 		}
 		let items = await objects.find({ _key: counts.smallestSet }, {
 			projection: { _id: 0, value: 1 },
-		}).toArray();
+		}).batchSize(counts.minCount + 1).toArray();
 
 		const otherSets = keys.filter(s => s !== counts.smallestSet);
 		for (let i = 0; i < otherSets.length; i++) {
@@ -21,7 +21,7 @@ module.exports = function (module) {
 			if (i === otherSets.length - 1) {
 				return await objects.countDocuments(query);
 			}
-			items = await objects.find(query, { projection: { _id: 0, value: 1 } }).toArray();
+			items = await objects.find(query, { projection: { _id: 0, value: 1 } }).batchSize(items.length + 1).toArray();
 		}
 	};
 
@@ -81,9 +81,13 @@ module.exports = function (module) {
 			return await intersectBatch(params);
 		}
 
-		let items = await objects.find({ _key: params.counts.smallestSet }, {
+		const cursorSmall = objects.find({ _key: params.counts.smallestSet }, {
 			projection: { _id: 0, value: 1 },
-		}).toArray();
+		});
+		if (params.counts.minCount > 1) {
+			cursorSmall.batchSize(params.counts.minCount + 1);
+		}
+		let items = await cursorSmall.toArray();
 		const project = { _id: 0, value: 1 };
 		if (params.withScores) {
 			project.score = 1;
@@ -94,6 +98,7 @@ module.exports = function (module) {
 		for (let i = 0; i < otherSets.length; i++) {
 			/* eslint-disable no-await-in-loop */
 			const cursor = objects.find({ _key: otherSets[i], value: { $in: items.map(i => i.value) } });
+			cursor.batchSize(items.length + 1);
 			// at the last step sort by sortSet
 			if (i === otherSets.length - 1) {
 				cursor.project(project).sort({ score: params.sort }).skip(params.start).limit(params.limit);
@@ -135,8 +140,15 @@ module.exports = function (module) {
 				items.push(nextItem);
 			}
 
-			const members = await Promise.all(otherSets.map(s => module.isSortedSetMembers(s, items.map(i => i.value))));
+			const members = await Promise.all(otherSets.map(async function (s) {
-			inters = inters.concat(items.filter((item, idx) => members.every(arr => arr[idx])));
+				const data = await module.client.collection('objects').find({
+					_key: s, value: { $in: items.map(i => i.value) },
+				}, {
+					projection: { _id: 0, value: 1 },
+				}).batchSize(items.length + 1).toArray();
+				return new Set(data.map(i => i.value));
+			}));
+			inters = inters.concat(items.filter(item => members.every(arr => arr.has(item.value))));
 			if (inters.length >= params.stop) {
 				done = true;
 				inters = inters.slice(params.start, params.stop + 1);