Ampr: cooked-id index preload and host FD LRU cache (#725)

Preload the app0 APR index during bind and bound the open host-file cache so streaming reads stay responsive under large title archives.
2026-08-01 23:49:44 +08:00 · 2026-07-31 11:13:33 +02:00
parent 532251c0c3
commit 93c9f14081
6 changed files with 841 additions and 23 deletions
@@ -0,0 +1,78 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using SharpEmu.Libs.Ampr;
+using Xunit;
+
+namespace SharpEmu.Libs.Tests.Ampr;
+
+public class AmprFileRegistryTests
+{
+    [Fact]
+    public void ComputeFileId_matches_utf8_fnv1a()
+    {
+        const string relative = "CoreData/foo/bar.bin";
+        Assert.Equal(FnvUtf8("$/" + relative), AmprFileRegistry.ComputeFileId("$/" + relative));
+        Assert.Equal(FnvUtf8("/app0/" + relative), AmprFileRegistry.ComputeFileId("/app0/" + relative));
+        Assert.Equal(FnvUtf8("app0/" + relative), AmprFileRegistry.ComputeFileId("app0/" + relative));
+        Assert.Equal(FnvUtf8(relative), AmprFileRegistry.ComputeFileId(relative));
+    }
+
+    [Fact]
+    public void RegisterApp0Relative_publishes_same_ids_as_string_hashes()
+    {
+        AmprFileRegistry.ClearForTests();
+        const string relative = "misc/loadouts/test.txt";
+        var host = Path.Combine(Path.GetTempPath(), "sharpemu-ampr-test", relative);
+        AmprFileRegistry.RegisterApp0RelativeForTests(relative, host);
+
+        Assert.True(AmprFileRegistry.TryGetHostPath(
+            AmprFileRegistry.ComputeFileId("$/" + relative), out var a));
+        Assert.True(AmprFileRegistry.TryGetHostPath(
+            AmprFileRegistry.ComputeFileId("/app0/" + relative), out var b));
+        Assert.True(AmprFileRegistry.TryGetHostPath(
+            AmprFileRegistry.ComputeFileId("app0/" + relative), out var c));
+        Assert.True(AmprFileRegistry.TryGetHostPath(
+            AmprFileRegistry.ComputeFileId(relative), out var d));
+        Assert.Equal(host, a);
+        Assert.Equal(host, b);
+        Assert.Equal(host, c);
+        Assert.Equal(host, d);
+    }
+
+    [Fact]
+    public void Register_publishes_all_app0_path_aliases()
+    {
+        AmprFileRegistry.ClearForTests();
+        const string relative = "scripts/cp11/cp11main.script";
+        var host = Path.Combine(Path.GetTempPath(), "sharpemu-ampr-test2", relative);
+        AmprFileRegistry.Register("$/" + relative, host);
+
+        Assert.True(AmprFileRegistry.TryGetHostPath(
+            AmprFileRegistry.ComputeFileId("$/" + relative), out var a));
+        Assert.True(AmprFileRegistry.TryGetHostPath(
+            AmprFileRegistry.ComputeFileId("/app0/" + relative), out var b));
+        Assert.True(AmprFileRegistry.TryGetHostPath(
+            AmprFileRegistry.ComputeFileId("app0/" + relative), out var c));
+        Assert.True(AmprFileRegistry.TryGetHostPath(
+            AmprFileRegistry.ComputeFileId(relative), out var d));
+        Assert.Equal(host, a);
+        Assert.Equal(host, b);
+        Assert.Equal(host, c);
+        Assert.Equal(host, d);
+    }
+
+    private static uint FnvUtf8(string text)
+    {
+        const uint offset = 2166136261;
+        const uint prime = 16777619;
+        var hash = offset;
+        foreach (var b in System.Text.Encoding.UTF8.GetBytes(text))
+        {
+            hash ^= b;
+            hash *= prime;
+        }
+
+        return hash;
+    }
+}