Add widget for weekly downloads chart with downloads data (#8208)

Author: szakarias

app/lib/frontend/handlers/package.dart

@@ -10,6 +10,7 @@ import 'package:_pub_shared/data/advisories_api.dart'
 import 'package:_pub_shared/utils/sdk_version_cache.dart';
 import 'package:meta/meta.dart';
 import 'package:neat_cache/neat_cache.dart';
+import 'package:pub_dev/service/download_counts/computations.dart';
 import 'package:pub_dev/service/security_advisories/backend.dart';
 import 'package:pub_dev/shared/versions.dart';
 import 'package:pub_dev/task/backend.dart';
@@ -453,6 +454,8 @@ Future<PackagePageData> loadPackagePageData(
   final scoreCardFuture = scoreCardBackend
       .getScoreCardData(packageName, versionName, package: package);
 
+  final weeklyDownloadCountsFuture = getWeeklyDownloads(package.name!);
+
   await Future.wait([
     latestReleasesFuture,
     isLikedFuture,
@@ -461,6 +464,7 @@ Future<PackagePageData> loadPackagePageData(
     assetFuture,
     isAdminFuture,
     scoreCardFuture,
+    weeklyDownloadCountsFuture,
   ]);
 
   final selectedVersion = await selectedVersionFuture;
@@ -484,6 +488,7 @@ Future<PackagePageData> loadPackagePageData(
     scoreCard: await scoreCardFuture,
     isAdmin: await isAdminFuture,
     isLiked: await isLikedFuture,
+    weeklyDownloadCounts: await weeklyDownloadCountsFuture,
   );
 }
 

app/lib/frontend/templates/views/pkg/info_box.dart

@@ -2,7 +2,9 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+import 'package:_pub_shared/format/encoding.dart';
 import 'package:pana/pana.dart';
+import 'package:pub_dev/service/download_counts/download_counts.dart';
 import 'package:pubspec_parse/pubspec_parse.dart' as pubspek;
 
 import '../../../../package/models.dart';
@@ -69,6 +71,8 @@ d.Node packageInfoBoxNode({
   }
   return d.fragment([
     labeledScores,
+    if (data.weeklyDownloadCounts != null)
+      _downloadsChart(data.weeklyDownloadCounts!),
     if (thumbnailUrl != null)
       d.div(classes: [
         'detail-screenshot-thumbnail'
@@ -105,6 +109,23 @@ d.Node packageInfoBoxNode({
   ]);
 }
 
+d.Node _downloadsChart(WeeklyDownloadCounts wdc) {
+  final container = d.div(
+      classes: ['weekly-downloads-sparkline'],
+      id: '-weekly-downloads-sparkline',
+      attributes: {
+        'data-widget': 'weekly-sparkline',
+        'data-weekly-sparkline-points':
+            _encodeForWeeklySparkline(wdc.weeklyDownloads, wdc.newestDate),
+      });
+  return container;
+}
+
+String _encodeForWeeklySparkline(List<int> downloads, DateTime newestDate) {
+  final date = newestDate.toUtc().millisecondsSinceEpoch ~/ 1000;
+  return encodeIntsAsLittleEndianBase64String([date, ...downloads]);
+}
+
 d.Node _publisher(String? publisherId) {
   return _block(
     'Publisher',

app/lib/package/models.dart

@@ -10,6 +10,7 @@ import 'package:clock/clock.dart';
 import 'package:json_annotation/json_annotation.dart';
 import 'package:pana/models.dart';
 import 'package:pub_dev/service/download_counts/backend.dart';
+import 'package:pub_dev/service/download_counts/download_counts.dart';
 import 'package:pub_dev/shared/markdown.dart';
 import 'package:pub_semver/pub_semver.dart';
 
@@ -1132,6 +1133,7 @@ class PackagePageData {
   final ScoreCardData scoreCard;
   final bool isAdmin;
   final bool isLiked;
+  final WeeklyDownloadCounts? weeklyDownloadCounts;
   PackageView? _view;
 
   PackagePageData({
@@ -1143,6 +1145,7 @@ class PackagePageData {
     required this.scoreCard,
     required this.isAdmin,
     required this.isLiked,
+    required this.weeklyDownloadCounts,
   }) : latestReleases = latestReleases ?? package.latestReleases;
 
   bool get hasReadme => versionInfo.assets.contains(AssetKind.readme);

app/lib/service/download_counts/computations.dart

@@ -6,11 +6,14 @@ import 'dart:math';
 
 import 'package:gcloud/storage.dart';
 import 'package:pub_dev/service/download_counts/backend.dart';
+import 'package:pub_dev/service/download_counts/download_counts.dart';
 import 'package:pub_dev/service/download_counts/models.dart';
 import 'package:pub_dev/shared/configuration.dart';
 import 'package:pub_dev/shared/storage.dart';
 import 'package:pub_dev/shared/utils.dart';
 
+import '../../shared/redis_cache.dart' show cache;
+
 Future<void> compute30DaysTotalTask() async {
   final allDownloadCounts = await downloadCountsBackend.listAllDownloadCounts();
   final totals = await compute30DayTotals(allDownloadCounts);
@@ -43,6 +46,17 @@ Future<void> upload30DaysTotal(Map<String, int> counts) async {
       jsonUtf8Encoder.convert(counts));
 }
 
+Future<WeeklyDownloadCounts?> getWeeklyDownloads(String package) async {
+  return (await cache.weeklyDownloadCounts(package).get(() async {
+    final wdc = await computeWeeklyDownloads(package);
+    if (wdc.newestDate == null) {
+      return null;
+    }
+    return WeeklyDownloadCounts(
+        weeklyDownloads: wdc.weeklyDownloads, newestDate: wdc.newestDate!);
+  }));
+}
+
 /// Computes `weeklyDownloads` starting from `newestDate` for [package].
 ///
 /// Each number in `weeklyDownloads` is the total number of downloads for

app/lib/service/download_counts/download_counts.dart

@@ -215,3 +215,18 @@ class CountData {
       _$CountDataFromJson(json);
   Map<String, dynamic> toJson() => _$CountDataToJson(this);
 }
+
+@JsonSerializable(includeIfNull: false)
+class WeeklyDownloadCounts {
+  final List<int> weeklyDownloads;
+  final DateTime newestDate;
+
+  WeeklyDownloadCounts({
+    required this.weeklyDownloads,
+    required this.newestDate,
+  });
+
+  factory WeeklyDownloadCounts.fromJson(Map<String, dynamic> json) =>
+      _$WeeklyDownloadCountsFromJson(json);
+  Map<String, dynamic> toJson() => _$WeeklyDownloadCountsToJson(this);
+}

app/lib/service/download_counts/download_counts.g.dart

@@ -247,6 +247,16 @@ class CachePatterns {
         decode: (d) => CountData.fromJson(d as Map<String, dynamic>),
       ))[package];
 
+  Entry<WeeklyDownloadCounts> weeklyDownloadCounts(String package) => _cache
+      .withPrefix('weekly-download-counts/')
+      .withTTL(Duration(hours: 6))
+      .withCodec(utf8)
+      .withCodec(json)
+      .withCodec(wrapAsCodec(
+        encode: (WeeklyDownloadCounts wdc) => wdc.toJson(),
+        decode: (d) => WeeklyDownloadCounts.fromJson(d as Map<String, dynamic>),
+      ))[package];
+
   Entry<List<LikeData>> userPackageLikes(String userId) => _cache
       .withPrefix('user-package-likes/')
       .withTTL(Duration(minutes: 60))