feature: parallels to download illusts

Pixiview.Android/Properties/AndroidManifest.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<manifest xmlns:android="http://schemas.android.com/apk/res/android" android:versionName="1.0.524" package="org.tsanie.pixiview" android:versionCode="16">
+<manifest xmlns:android="http://schemas.android.com/apk/res/android" android:versionName="1.0.525" package="org.tsanie.pixiview" android:versionCode="18">
 	<uses-sdk android:minSdkVersion="25" android:targetSdkVersion="28" />
 	<application android:label="Pixiview" android:icon="@mipmap/icon" android:roundIcon="@mipmap/icon_round"></application>
 	<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

Pixiview.iOS.OpenExtension/Info.plist

@@ -29,8 +29,8 @@
 		<string>com.apple.share-services</string>
 	</dict>
 	<key>CFBundleShortVersionString</key>
-	<string>1.0.524</string>
+	<string>1.0.525</string>
 	<key>CFBundleVersion</key>
-	<string>16</string>
+	<string>18</string>
 </dict>
 </plist>

Pixiview.iOS/Info.plist

@@ -79,9 +79,9 @@
 		</dict>
 	</array>
 	<key>CFBundleShortVersionString</key>
-	<string>1.0.524</string>
+	<string>1.0.525</string>
 	<key>CFBundleVersion</key>
-	<string>16</string>
+	<string>18</string>
 	<key>CFBundleDevelopmentRegion</key>
 	<string>China</string>
 </dict>

Pixiview/Illust/IllustCollectionPage.cs

@@ -717,9 +717,12 @@ namespace Pixiview.Illust
                 return true;
             }, tagIndex: tag);
 
-            lock (sync)
+            if (task != null)
             {
-                tasks.Enqueue(task);
+                lock (sync)
+                {
+                    tasks.Enqueue(task);
+                }
             }
         }
 

Pixiview/Illust/RecommendsPage.xaml.cs

@@ -315,7 +315,7 @@ namespace Pixiview.Illust
             if (illust.ImageUrl != null)
             {
                 var url = Configs.GetThumbnailUrl(illust.ImageUrl);
-                var image = Stores.LoadPreviewImage(url, true, force: false);
+                var image = Stores.LoadPreviewImage(url, false);
                 if (image == null)
                 {
                     image = Stores.LoadThumbnailImage(url, true);

Pixiview/Illust/ViewIllustPage.xaml.cs

@@ -400,7 +400,7 @@ namespace Pixiview.Illust
                 task.Dispose();
                 task = null;
             }
-            task = ParallelTask.Start("view.illusts", 0, items.Length, Configs.MaxPageThreads, i =>
+            task = ParallelTask.Start("view.illusts", 0, items.Length, 2, i =>
             {
                 DoLoadImage(i);
                 return true;
@@ -439,7 +439,7 @@ namespace Pixiview.Illust
                 }
             }
             item.Loading = true;
-            var image = Stores.LoadPreviewImage(item.PreviewUrl, true, force: force);
+            var image = Stores.LoadPreviewImage(item.PreviewUrl, true, IllustItem.Id, force: force);
             if (image != null)
             {
                 item.Image = image;

Pixiview/Utils/Extensions.cs

@@ -107,7 +107,8 @@ namespace Pixiview.Utils
                 return null;
             }
             var task = new ParallelTask(tag, from, toExclusive, maxCount, action, tagIndex, complete);
-            return task.Start();
+            task.Start();
+            return task;
         }
 
         private readonly object sync = new object();
@@ -141,10 +142,9 @@ namespace Pixiview.Utils
             this.complete = complete;
         }
 
-        public ParallelTask Start()
+        public void Start()
         {
             _ = ThreadPool.QueueUserWorkItem(DoStart);
-            return this;
         }
 
         private void DoStart(object state)

Pixiview/Utils/HttpUtility.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Net;
@@ -6,6 +7,7 @@ using System.Net.Http;
 using System.Net.Http.Headers;
 using System.Text;
 using System.Threading;
+using System.Threading.Tasks;
 using Newtonsoft.Json;
 
 namespace Pixiview.Utils
@@ -204,6 +206,112 @@ namespace Pixiview.Utils
             }
         }
 
+        public static Task<string> DownloadImageAsync(string url, string id, string working, string folder)
+        {
+            try
+            {
+                var directory = Path.Combine(working, folder);
+                if (!Directory.Exists(directory))
+                {
+                    Directory.CreateDirectory(directory);
+                }
+                var file = Path.Combine(directory, Path.GetFileName(url));
+                var proxy = Configs.Proxy;
+                var referer = new Uri(string.Format(Configs.UrlIllust, id));
+                var handler = new HttpClientHandler
+                {
+                    UseCookies = false
+                };
+                if (proxy != null)
+                {
+                    handler.Proxy = proxy;
+                    handler.UseProxy = true;
+                }
+                var client = new HttpClient(handler)
+                {
+                    Timeout = TimeSpan.FromSeconds(30)
+                };
+                long size;
+                DateTimeOffset lastModified;
+                using (var request = new HttpRequestMessage(HttpMethod.Head, url))
+                {
+                    var headers = request.Headers;
+                    headers.Add("Accept", Configs.AcceptPureImage);
+                    headers.Add("Accept-Language", Configs.AcceptLanguage);
+                    headers.Referrer = referer;
+                    headers.Add("User-Agent", Configs.UserAgent);
+                    using (var response = client.SendAsync(request, HttpCompletionOption.ResponseHeadersRead).Result)
+                    {
+                        size = response.Content.Headers.ContentLength.Value;
+                        lastModified = response.Content.Headers.LastModified.Value;
+#if DEBUG
+                        App.DebugPrint($"content length: {size:n0} bytes, last modified: {lastModified}");
+#endif
+                    }
+                }
+
+                // segments
+                const int SIZE = 50000;
+                var list = new List<(long from, long to)>();
+                for (var i = 0L; i < size; i += SIZE)
+                {
+                    long to;
+                    if (i + SIZE >= size)
+                    {
+                        to = size - 1;
+                    }
+                    else
+                    {
+                        to = i + SIZE - 1;
+                    }
+                    list.Add((i, to));
+                }
+
+                var data = new byte[size];
+                var task = new TaskCompletionSource<string>();
+
+                ParallelTask.Start($"download.async.{id}", 0, list.Count, 6, i =>
+                {
+                    var (from, to) = list[i];
+                    using (var request = new HttpRequestMessage(HttpMethod.Get, url))
+                    {
+                        var headers = request.Headers;
+                        headers.Add("Accept", Configs.AcceptPureImage);
+                        headers.Add("Accept-Language", Configs.AcceptLanguage);
+                        headers.Add("Accept-Encoding", "identity");
+                        headers.IfRange = new RangeConditionHeaderValue(lastModified);
+                        headers.Range = new RangeHeaderValue(from, to);
+                        headers.Referrer = referer;
+                        headers.Add("User-Agent", Configs.UserAgent);
+                        using (var response = client.SendAsync(request, HttpCompletionOption.ResponseHeadersRead).Result)
+                        using (var ms = new MemoryStream(data, (int)from, (int)(to - from + 1)))
+                        {
+                            response.Content.CopyToAsync(ms).Wait();
+#if DEBUG
+                            App.DebugPrint($"downloaded range: from ({from:n0}) to ({to:n0})");
+#endif
+                        }
+                    }
+                    return true;
+                },
+                complete: () =>
+                {
+                    using (var fs = File.OpenWrite(file))
+                    {
+                        fs.Write(data, 0, data.Length);
+                    }
+                    task.SetResult(file);
+                });
+
+                return task.Task;
+            }
+            catch (Exception ex)
+            {
+                App.DebugError("image.download.async", ex.Message);
+                return Task.FromResult<string>(null);
+            }
+        }
+
         private static HttpResponseMessage Download(string url, Action<HttpRequestHeaders> headerAction, HttpContent post = null)
         {
 #if DEBUG

Pixiview/Utils/Stores.cs

@@ -6,6 +6,7 @@ using System.Net;
 using System.Net.Http;
 using System.Text;
 using System.Text.RegularExpressions;
+using System.Threading.Tasks;
 using Newtonsoft.Json;
 using Pixiview.Illust;
 using Xamarin.Essentials;
@@ -590,8 +591,12 @@ namespace Pixiview.Utils
             return LoadImage(url, PersonalFolder, imageFolder, true);
         }
 
-        public static ImageSource LoadPreviewImage(string url, bool downloading, bool force = false)
+        public static ImageSource LoadPreviewImage(string url, bool downloading, string id = null, bool force = false)
         {
+            if (downloading)
+            {
+                return LoadImageAsync(url, id, PersonalFolder, previewFolder, force).Result;
+            }
             return LoadImage(url, PersonalFolder, previewFolder, downloading, force);
         }
 
@@ -656,6 +661,37 @@ namespace Pixiview.Utils
             }
             return image;
         }
+
+        private static Task<ImageSource> LoadImageAsync(string url, string id, string working, string folder, bool force = false)
+        {
+            var file = Path.Combine(working, folder, Path.GetFileName(url));
+            ImageSource image;
+            if (!force && File.Exists(file))
+            {
+                try
+                {
+                    image = ImageSource.FromFile(file);
+                }
+                catch (Exception ex)
+                {
+                    App.DebugError("image.load", $"failed to load image from file: {file}, error: {ex.Message}");
+                    image = null;
+                }
+            }
+            else
+            {
+                image = null;
+            }
+            if (image == null)
+            {
+                file = HttpUtility.DownloadImageAsync(url, id, working, folder).Result;
+                if (file != null)
+                {
+                    image = ImageSource.FromFile(file);
+                }
+            }
+            return Task.FromResult(image);
+        }
     }
 
     public class IllustFavorite
@@ -772,9 +808,9 @@ namespace Pixiview.Utils
         }
 
 #if __IOS__
-        public static System.Threading.Tasks.Task<bool> RequestCookieContainer(WebKit.WKHttpCookieStore cookieStore)
+        public static Task<bool> RequestCookieContainer(WebKit.WKHttpCookieStore cookieStore)
         {
-            var task = new System.Threading.Tasks.TaskCompletionSource<bool>();
+            var task = new TaskCompletionSource<bool>();
             cookieStore.GetAllCookies(cookies =>
             {
                 var list = new List<string>();
@@ -825,6 +861,7 @@ namespace Pixiview.Utils
 
         public const string UserAgent = "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36";
         public const string AcceptImage = "image/png,image/svg+xml,image/*;q=0.8,video/*;q=0.8,*/*;q=0.5";
+        public const string AcceptPureImage = "image/*,*/*;q=0.8";
         public const string AcceptJson = "application/json";
         public const string AcceptUrlEncoded = "application/x-www-form-urlencoded";
         //public const string AcceptEncoding = "gzip, deflate";