Reduce idle memory: fonts on demand, trim after a tray start, malloc trim on Linux

docs/ARCHITECTURE.md

@@ -432,7 +432,8 @@ way to draw (`WindowsRendering`): `dcomp` (skip WinUI composition), `redirection
 surface) or `software` (no GPU); unset or `auto` keeps the defaults. Filee reads it at start. On ARM64, Avalonia's
 Adreno blocklist draws on the CPU through the Microsoft Basic Render Driver (issue #236), and three values try the GPU
 there again: `gpu` (Direct3D on the first adapter that isn't the Basic Render Driver), `vulkan` and `wgl` (OpenGL), the
-last two falling back to software when they can't start.
+last two falling back to software when they can't start. On Linux (X11) only `software` applies: the GPU's driver stays
+in memory for as long as Filee runs, also with no window open, so this is the way to a smaller tray app (issue #957).
 
 ## Explorer integration
 

src/Filee.App/App.axaml.cs

@@ -144,6 +144,8 @@ private void Start(IClassicDesktopStyleApplicationLifetime desktop)
             log.LogInformation("{Rendering}", WindowsRendering.Describe(Environment.GetEnvironmentVariable(WindowsRendering.Variable)));
             TransparentWindows.Watch(log);
         }
+        else if (Program.LinuxDrawsInSoftware)
+            log.LogInformation("Rendering: software ({Variable})", WindowsRendering.Variable);
         // macOS: ask for Accessibility with the system's own alert when the user opened Filee (not at sign-in) and
         // a drag gesture is on, once ever (see ShouldAskForPermission). The home page keeps a reminder until it is
         // given. Asked once the main window is up: asked earlier, the alert ends up behind it.
@@ -213,6 +215,9 @@ private void Start(IClassicDesktopStyleApplicationLifetime desktop)
                     });
             };
         WatchForUpdates(store);
+        // Started to the tray (at sign-in): no job or window would ask for a trim, however long Filee waits there (#957).
+        if (AppHost.Get<WindowService>().Main is null)
+            AppHost.Get<MemoryTrimmer>().Request();
         // Filee runs as administrator while Explorer doesn't (an installer started "as administrator" started it):
         // say so once, next to the tray, and on the Home page for as long as it lasts.
         if (AppHost.Get<ElevationService>().ShellCannotReachFilee)

src/Filee.App/FileeFontCollection.cs

@@ -0,0 +1,104 @@
+// The embedded Noto fonts (build/fetch-fonts.ps1), each family read when text first asks for it (issue #957). Avalonia's
+// EmbeddedFontCollection opens every file at the start, and SkiaSharp copies a font it opens from a stream into native
+// memory for good. So all 18 files (37 MB) stayed in memory on top of the pages of Filee.dll that the copying read, also
+// in a Filee started to the tray that has drawn no text yet. Since a letter is only matched in the family asked for, the
+// families after the one that has it are never asked for: Noto Sans SC stays unread until a chain reaches it.
+
+using System.Collections;
+using System.Diagnostics.CodeAnalysis;
+using System.Globalization;
+using Avalonia.Media;
+using Avalonia.Media.Fonts;
+using Avalonia.Platform;
+
+namespace Filee.App;
+
+/// <summary>
+/// Embedded Noto fonts: <c>fonts:Filee#Noto Sans</c>, <c>#Noto Sans JP</c>, <c>#Noto Sans KR</c>,
+/// <c>#Noto Sans SC</c>, <c>#Noto Sans Devanagari</c>, <c>#Noto Sans Arabic</c>, <c>#Noto Sans Thai</c>.
+/// <para>
+/// A letter is only matched in the family asked for, so the order of SoftPalette's font chain decides (#1095). Avalonia's
+/// own collection, asked for Noto Sans about a Han character, answers with the first family of its own that has it,
+/// Noto Sans JP, before the font manager reaches the chain's next family: every language drew Han in Japanese shapes,
+/// up to the first character that font lacks. Text has no culture to go by either, as TextBlock passes none. It takes
+/// this wrapper rather than a subclass: the font manager skips the virtual method on Avalonia's collections.
+/// </para>
+/// </summary>
+internal sealed class FileeFontCollection : IFontCollection
+{
+    internal static readonly Uri Source = new("avares://Filee/Assets/Fonts", UriKind.Absolute);
+
+    private readonly ReadFonts _fonts;
+    private readonly Lock _lock = new();
+    private readonly HashSet<string> _asked = new(StringComparer.OrdinalIgnoreCase);
+
+    internal FileeFontCollection(string key = "fonts:Filee") => _fonts = new ReadFonts(new Uri(key, UriKind.Absolute));
+
+    public Uri Key => _fonts.Key;
+
+    /// <summary>The families read so far.</summary>
+    public int Count => _fonts.Count;
+
+    public FontFamily this[int index] => _fonts[index];
+
+    public bool TryMatchCharacter(int codepoint, FontStyle fontStyle, FontWeight fontWeight, FontStretch fontStretch,
+        string? familyName, CultureInfo? culture, out Typeface typeface)
+    {
+        typeface = default;
+        // No culture from here on: the family is settled, and one would send it looking elsewhere again.
+        return familyName is not null
+            && TryGetGlyphTypeface(familyName, fontStyle, fontWeight, fontStretch, out var face)
+            && face.CharacterToGlyphMap.TryGetGlyph(codepoint, out _)
+            && _fonts.TryMatchCharacter(codepoint, fontStyle, fontWeight, fontStretch, familyName, null, out typeface);
+    }
+
+    public bool TryGetGlyphTypeface(string familyName, FontStyle style, FontWeight weight, FontStretch stretch,
+        [NotNullWhen(true)] out GlyphTypeface? glyphTypeface)
+    {
+        ReadFamily(familyName);
+        return _fonts.TryGetGlyphTypeface(familyName, style, weight, stretch, out glyphTypeface);
+    }
+
+    public bool TryGetFamilyTypefaces(string familyName, [NotNullWhen(true)] out IReadOnlyList<Typeface>? familyTypefaces)
+    {
+        ReadFamily(familyName);
+        return _fonts.TryGetFamilyTypefaces(familyName, out familyTypefaces);
+    }
+
+    public bool TryCreateSyntheticGlyphTypeface(GlyphTypeface glyphTypeface, FontStyle style, FontWeight weight, FontStretch stretch,
+        [NotNullWhen(true)] out GlyphTypeface? syntheticGlyphTypeface) =>
+        _fonts.TryCreateSyntheticGlyphTypeface(glyphTypeface, style, weight, stretch, out syntheticGlyphTypeface);
+
+    public bool TryGetNearestMatch(string familyName, FontStyle style, FontWeight weight, FontStretch stretch,
+        [NotNullWhen(true)] out GlyphTypeface? glyphTypeface)
+    {
+        ReadFamily(familyName);
+        return _fonts.TryGetNearestMatch(familyName, style, weight, stretch, out glyphTypeface);
+    }
+
+    public IEnumerator<FontFamily> GetEnumerator() => _fonts.GetEnumerator();
+    IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+    public void Dispose() => ((IDisposable)_fonts).Dispose();
+
+    /// <summary>"NotoSansKR-Bold.otf" belongs to "Noto Sans KR", and not to "Noto Sans".</summary>
+    internal static bool IsFileOf(string familyName, string fileName) =>
+        fileName.StartsWith(familyName.Replace(" ", "", StringComparison.Ordinal) + "-", StringComparison.OrdinalIgnoreCase);
+
+    private void ReadFamily(string familyName)
+    {
+        lock (_lock)
+        {
+            if (!_asked.Add(familyName))
+                return;
+            // None when the fonts weren't fetched: the family isn't found, and the chain goes on to the system's fonts.
+            foreach (var asset in AssetLoader.GetAssets(Source, null))
+                if (IsFileOf(familyName, Path.GetFileName(asset.AbsolutePath)))
+                    _fonts.TryAddFontSource(asset);
+        }
+    }
+
+    private sealed class ReadFonts(Uri key) : FontCollectionBase
+    {
+        public override Uri Key => key;
+    }
+}

src/Filee.App/Program.cs

@@ -7,12 +7,9 @@
 //  3. Start Avalonia. The app lives in the tray, so it only exits via the tray "Quit" command (or --quit).
 
 using System.Diagnostics;
-using System.Diagnostics.CodeAnalysis;
-using System.Globalization;
 using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Media;
-using Avalonia.Media.Fonts;
 using Filee.App.Services;
 using Filee.Core.Platform;
 using Filee.Core.Settings;
@@ -293,6 +290,10 @@ public static AppBuilder BuildAvaloniaApp()
                 WindowsRendering.Normalize(Environment.GetEnvironmentVariable(WindowsRendering.Variable)),
                 adapters => Log.LogInformation("Graphics adapters: {Adapters}", adapters)));
 
+        // The GPU's driver stays in memory for as long as Filee runs, also with no window open (#957).
+        if (LinuxDrawsInSoftware)
+            builder = builder.With(new X11PlatformOptions { RenderingMode = [X11RenderingMode.Software] });
+
         builder = builder
             .ConfigureFonts(fonts => fonts.AddFontCollection(new FileeFontCollection()))
 #if DEBUG
@@ -303,57 +304,8 @@ public static AppBuilder BuildAvaloniaApp()
         AvaloniaLogForwarder.Install(Log);
         return builder;
     }
-}
-
-/// <summary>
-/// Embedded Noto fonts: <c>fonts:Filee#Noto Sans</c>, <c>#Noto Sans JP</c>, <c>#Noto Sans KR</c>,
-/// <c>#Noto Sans SC</c>, <c>#Noto Sans Devanagari</c>, <c>#Noto Sans Arabic</c>, <c>#Noto Sans Thai</c>.
-/// <para>
-/// A letter is only matched in the family asked for, so the order of SoftPalette's font chain decides (#1095). Avalonia's
-/// own collection, asked for Noto Sans about a Han character, answers with the first family of its own that has it,
-/// Noto Sans JP, before the font manager reaches the chain's next family: every language drew Han in Japanese shapes,
-/// up to the first character that font lacks. Text has no culture to go by either, as TextBlock passes none. It takes
-/// this wrapper rather than a subclass: the font manager skips the virtual method on Avalonia's collections.
-/// </para>
-/// </summary>
-internal sealed class FileeFontCollection : IFontCollection
-{
-    private readonly EmbeddedFontCollection _fonts = new(
-        new Uri("fonts:Filee", UriKind.Absolute),
-        new Uri("avares://Filee/Assets/Fonts", UriKind.Absolute));
-
-    public Uri Key => _fonts.Key;
-    public int Count => _fonts.Count;
-    public FontFamily this[int index] => _fonts[index];
-
-    public bool TryMatchCharacter(int codepoint, FontStyle fontStyle, FontWeight fontWeight, FontStretch fontStretch,
-        string? familyName, CultureInfo? culture, out Typeface typeface)
-    {
-        typeface = default;
-        // No culture from here on: the family is settled, and one would send it looking elsewhere again.
-        return familyName is not null
-            && _fonts.TryGetGlyphTypeface(familyName, fontStyle, fontWeight, fontStretch, out var face)
-            && face.CharacterToGlyphMap.TryGetGlyph(codepoint, out _)
-            && _fonts.TryMatchCharacter(codepoint, fontStyle, fontWeight, fontStretch, familyName, null, out typeface);
-    }
-
-    public bool TryGetGlyphTypeface(string familyName, FontStyle style, FontWeight weight, FontStretch stretch,
-        [NotNullWhen(true)] out GlyphTypeface? glyphTypeface) =>
-        _fonts.TryGetGlyphTypeface(familyName, style, weight, stretch, out glyphTypeface);
-
-    public bool TryGetFamilyTypefaces(string familyName,
-        [NotNullWhen(true)] out IReadOnlyList<Typeface>? familyTypefaces) =>
-        _fonts.TryGetFamilyTypefaces(familyName, out familyTypefaces);
-
-    public bool TryCreateSyntheticGlyphTypeface(GlyphTypeface glyphTypeface, FontStyle style, FontWeight weight, FontStretch stretch,
-        [NotNullWhen(true)] out GlyphTypeface? syntheticGlyphTypeface) =>
-        _fonts.TryCreateSyntheticGlyphTypeface(glyphTypeface, style, weight, stretch, out syntheticGlyphTypeface);
-
-    public bool TryGetNearestMatch(string familyName, FontStyle style, FontWeight weight, FontStretch stretch,
-        [NotNullWhen(true)] out GlyphTypeface? glyphTypeface) =>
-        _fonts.TryGetNearestMatch(familyName, style, weight, stretch, out glyphTypeface);
 
-    public IEnumerator<FontFamily> GetEnumerator() => _fonts.GetEnumerator();
-    System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() => GetEnumerator();
-    public void Dispose() => ((IDisposable)_fonts).Dispose();
+    /// <summary><c>FILEE_RENDERING=software</c> on Linux.</summary>
+    internal static bool LinuxDrawsInSoftware => OperatingSystem.IsLinux()
+        && WindowsRendering.Normalize(Environment.GetEnvironmentVariable(WindowsRendering.Variable)) == "software";
 }

src/Filee.App/Services/MemoryTrimmer.cs

@@ -1,10 +1,11 @@
-// Gives memory back while Filee waits in the tray (issue #119): a while after the last conversion finished, and after
-// the main window was released. Large images grow the managed heap and the engines' caches, and the garbage collector
+// Gives memory back while Filee waits in the tray (issues #119, #957): a while after the last conversion finished, after
+// the main window was released, and after a start without a window. Large images grow the managed heap and the engines' caches, and the garbage collector
 // keeps that memory committed for the next allocation, so Filee stayed hundreds of MB above its idle size.
 
 using System.Diagnostics;
 using Filee.Core.Conversion;
 using Filee.Engines.Infrastructure;
+using Filee.Platform.Linux;
 using Filee.Platform.Windows;
 using Microsoft.Extensions.Logging;
 
@@ -74,36 +75,57 @@ private void OnQuiet()
         Interlocked.Increment(ref _trims);
     }
 
-    /// <summary>Drops the engines' caches, collects every generation, then trims the working set (Windows).</summary>
+    /// <summary>
+    /// Drops the engines' caches, collects every generation, then trims the working set (Windows) or gives malloc's free
+    /// memory back (Linux).
+    /// </summary>
     internal static void Trim(ILogger log)
     {
         try
         {
             var watch = Stopwatch.StartNew();
             var before = PrivateMegabytes();
+            var linuxBefore = ProcessMemoryUsage.Current();
             EngineCaches.Release();
-            // Without compacting: garbage is freed and empty heap regions are decommitted all the same. Compaction was
-            // once blamed for a CI crash in Skia (sk_pngencoder_encode) after a trim; the cause was tests that let a
-            // captured frame be collected while Avalonia encoded it (WriteableBitmap.Save encodes a snapshot that
-            // doesn't own the pixels, and the finalizers this trim runs freed them). Nothing in Filee leaves native
-            // code with a pointer into managed memory: NativeMemoryStressTests converts under constant compaction.
             GC.Collect(GC.MaxGeneration, GCCollectionMode.Forced, blocking: true, compacting: false);
             GC.WaitForPendingFinalizers();
-            GC.Collect(GC.MaxGeneration, GCCollectionMode.Forced, blocking: true, compacting: false);
+            // Aggressive: a forced collection frees the garbage but keeps the empty heap regions committed for the next
+            // allocation (hundreds of MB after a large conversion), and only this one decommits them all. It compacts.
+            // Compaction was once blamed for a CI crash in Skia (sk_pngencoder_encode) after a trim; the cause was tests
+            // that let a captured frame be collected while Avalonia encoded it (WriteableBitmap.Save encodes a snapshot
+            // that doesn't own the pixels, and the finalizers this trim runs freed them). Nothing in Filee leaves native
+            // code with a pointer into managed memory: NativeMemoryStressTests converts under constant compaction.
+            GC.Collect(GC.MaxGeneration, GCCollectionMode.Aggressive, blocking: true, compacting: true);
             ProcessMemory.TrimWorkingSet();
-            log.LogInformation("Trimmed memory: private {Before} MB → {After} MB (managed heap {Heap} MB) in {Elapsed} ms",
-                before, PrivateMegabytes(), GC.GetTotalMemory(false) / (1024 * 1024), watch.ElapsedMilliseconds);
+            NativeHeap.Trim();
+            var committed = GC.GetGCMemoryInfo().TotalCommittedBytes / Megabyte;
+            if (linuxBefore is { } own && ProcessMemoryUsage.Current() is { } now)
+            {
+                // Windows' "private" means nothing here (see ProcessMemoryUsage). The split is what a report needs: what
+                // is the runtime's, what is malloc's, and what is left (mapped files, stacks, JIT code).
+                var malloc = NativeHeap.Usage();
+                log.LogInformation("Trimmed memory: own {Before} MB → {After} MB, resident {Resident} MB, anonymous {Anonymous} MB " +
+                                   "(managed heap {Heap} MB of {Committed} MB committed, malloc {MallocUsed} MB used, {MallocFree} MB free) in {Elapsed} ms",
+                    own.OwnBytes / Megabyte, now.OwnBytes / Megabyte, now.ResidentBytes / Megabyte, now.AnonymousBytes / Megabyte,
+                    GC.GetTotalMemory(false) / Megabyte, committed,
+                    malloc?.InUseBytes / Megabyte, malloc?.FreeBytes / Megabyte, watch.ElapsedMilliseconds);
+                return;
+            }
+            log.LogInformation("Trimmed memory: private {Before} MB → {After} MB (managed heap {Heap} MB of {Committed} MB committed) in {Elapsed} ms",
+                before, PrivateMegabytes(), GC.GetTotalMemory(false) / Megabyte, committed, watch.ElapsedMilliseconds);
         }
         catch (Exception ex) when (ex is not OutOfMemoryException)
         {
             log.LogWarning(ex, "Could not trim memory");
         }
     }
 
+    private const long Megabyte = 1024 * 1024;
+
     private static long PrivateMegabytes()
     {
         using var process = Process.GetCurrentProcess();
-        return process.PrivateMemorySize64 / (1024 * 1024);
+        return process.PrivateMemorySize64 / Megabyte;
     }
 
     public void Dispose()

src/Filee.App/Services/WindowService.cs

@@ -278,6 +278,7 @@ public void ShowImageEditWindow(IReadOnlyList<string> files, Preset preset)
         {
             if (_imageEdit == win)
                 _imageEdit = null;
+            trimmer.Request();
         };
         _imageEdit = win;
         win.Show();
@@ -408,6 +409,7 @@ public void ShowCropOverlay(IReadOnlyList<string> files, Preset preset, PixelPoi
         {
             if (_cropOverlay == win)
                 _cropOverlay = null;
+            trimmer.Request();
         };
         _cropOverlay = win;
         win.Show();
@@ -429,6 +431,7 @@ public void ShowPdfPageEditor(IReadOnlyList<string> files, Preset preset, bool a
         {
             if (_pdfPageEditor == win)
                 _pdfPageEditor = null;
+            trimmer.Request();
         };
         if (addPages)
             win.Opened += async (_, _) => await win.PickAndAddAsync();