.

src/Sentry.Android.AssemblyReader/AndroidAssemblyReader.cs

@@ -17,70 +17,4 @@ public void Dispose()
     {
         ZipArchive.Dispose();
     }
-
-    internal static PEReader CreatePEReader(string assemblyName, MemoryStream inputStream, DebugLogger? logger)
-    {
-        var decompressedStream = TryDecompressLZ4(assemblyName, inputStream, logger);
-
-        // Use the decompressed stream, or if null, i.e. it wasn't compressed, use the original.
-        return new PEReader(decompressedStream ?? inputStream);
-    }
-
-    /// <summary>
-    /// The DLL may be LZ4 compressed, see https://github.com/xamarin/xamarin-android/pull/4686
-    /// In particular: https://github.com/dotnet/android/blob/44c5c30d3da692c54ca27d4a41571ef20b73670f/src/Xamarin.Android.Build.Tasks/Utilities/AssemblyCompression.cs#L96-L104
-    /// The format is:
-    ///    [ 4 byte magic header ] (XALZ)
-    ///    [ 4 byte descriptor header index ]
-    ///    [ 4 byte uncompressed payload length ]
-    ///    [rest: lz4 compressed payload]
-    /// </summary>
-    /// <seealso href="https://github.com/xamarin/xamarin-android/blob/c92702619f5fabcff0ed88e09160baf9edd70f41/tools/decompress-assemblies/main.cs#L26" />
-    private static Stream? TryDecompressLZ4(string assemblyName, MemoryStream inputStream, DebugLogger? logger)
-    {
-        const uint compressedDataMagic = 0x5A4C4158; // 'XALZ', little-endian
-        const int payloadOffset = 12;
-        var reader = new BinaryReader(inputStream);
-        if (reader.ReadUInt32() != compressedDataMagic)
-        {
-            // Restore the input stream to the beginning if we're not decompressing.
-            inputStream.Position = 0;
-            return null;
-        }
-        reader.ReadUInt32(); // ignore descriptor index, we don't need it
-        var decompressedLength = reader.ReadInt32();
-        Debug.Assert(inputStream.Position == payloadOffset);
-        var inputLength = (int)(inputStream.Length - payloadOffset);
-
-        logger?.Invoke("Decompressing assembly ({0} bytes uncompressed) using LZ4", decompressedLength);
-
-        var outputStream = new MemoryStream(decompressedLength);
-
-        // We're writing to the underlying array manually, so we need to set the length.
-        outputStream.SetLength(decompressedLength);
-        var outputBuffer = outputStream.GetBuffer();
-
-        var inputBuffer = inputStream is MemorySlice slice ? slice.FullBuffer : inputStream.GetBuffer();
-        var offset = inputStream is MemorySlice memorySlice ? memorySlice.Offset + payloadOffset : payloadOffset;
-        var decoded = LZ4Codec.Decode(inputBuffer, offset, inputLength, outputBuffer, 0, decompressedLength);
-        if (decoded != decompressedLength)
-        {
-            throw new Exception($"Failed to decompress LZ4 data of assembly {assemblyName} - decoded {decoded} instead of expected {decompressedLength} bytes");
-        }
-        return outputStream;
-    }
-
-    // Allows consumer to access the underlying buffer even if the MemoryStream is created as a slice over another.
-    // Plain MemoryStream would throw "MemoryStream's internal buffer cannot be accessed."
-    protected class MemorySlice : MemoryStream
-    {
-        public readonly int Offset;
-        public readonly byte[] FullBuffer;
-
-        public MemorySlice(MemoryStream other, int offset, int size) : base(other.GetBuffer(), offset, size, writable: false)
-        {
-            Offset = offset;
-            FullBuffer = other.GetBuffer();
-        }
-    }
 }

src/Sentry.Android.AssemblyReader/ArchiveUtils.cs

@@ -0,0 +1,72 @@
+namespace Sentry.Android.AssemblyReader;
+
+internal static class ArchiveUtils
+{
+    internal static PEReader CreatePEReader(string assemblyName, MemoryStream inputStream, DebugLogger? logger)
+    {
+        var decompressedStream = TryDecompressLZ4(assemblyName, inputStream, logger); // Returns null if not compressed
+        return new PEReader(decompressedStream ?? inputStream);
+    }
+
+    internal static MemoryStream Extract(this ZipArchiveEntry zipEntry)
+    {
+        var memStream = new MemoryStream((int)zipEntry.Length);
+        using var zipStream = zipEntry.Open();
+        zipStream.CopyTo(memStream);
+        memStream.Position = 0;
+        return memStream;
+    }
+
+    /// <summary>
+    /// The DLL may be LZ4 compressed, see https://github.com/xamarin/xamarin-android/pull/4686
+    /// In particular: https://github.com/dotnet/android/blob/44c5c30d3da692c54ca27d4a41571ef20b73670f/src/Xamarin.Android.Build.Tasks/Utilities/AssemblyCompression.cs#L96-L104
+    /// The format is:
+    ///    [ 4 byte magic header ] (XALZ)
+    ///    [ 4 byte descriptor header index ]
+    ///    [ 4 byte uncompressed payload length ]
+    ///    [rest: lz4 compressed payload]
+    /// </summary>
+    /// <seealso href="https://github.com/xamarin/xamarin-android/blob/c92702619f5fabcff0ed88e09160baf9edd70f41/tools/decompress-assemblies/main.cs#L26" />
+    private static Stream? TryDecompressLZ4(string assemblyName, MemoryStream inputStream, DebugLogger? logger)
+    {
+        const uint compressedDataMagic = 0x5A4C4158; // 'XALZ', little-endian
+        const int payloadOffset = 12;
+        var reader = new BinaryReader(inputStream);
+        if (reader.ReadUInt32() != compressedDataMagic)
+        {
+            // Restore the input stream to the beginning if we're not decompressing.
+            inputStream.Position = 0;
+            return null;
+        }
+        reader.ReadUInt32(); // ignore descriptor index, we don't need it
+        var decompressedLength = reader.ReadInt32();
+        Debug.Assert(inputStream.Position == payloadOffset);
+        var inputLength = (int)(inputStream.Length - payloadOffset);
+
+        logger?.Invoke("Decompressing assembly ({0} bytes uncompressed) using LZ4", decompressedLength);
+
+        var outputStream = new MemoryStream(decompressedLength);
+
+        // We're writing to the underlying array manually, so we need to set the length.
+        outputStream.SetLength(decompressedLength);
+        var outputBuffer = outputStream.GetBuffer();
+
+        var inputBuffer = inputStream is MemorySlice slice ? slice.FullBuffer : inputStream.GetBuffer();
+        var offset = inputStream is MemorySlice memorySlice ? memorySlice.Offset + payloadOffset : payloadOffset;
+        var decoded = LZ4Codec.Decode(inputBuffer, offset, inputLength, outputBuffer, 0, decompressedLength);
+        if (decoded != decompressedLength)
+        {
+            throw new Exception($"Failed to decompress LZ4 data of assembly {assemblyName} - decoded {decoded} instead of expected {decompressedLength} bytes");
+        }
+        return outputStream;
+    }
+
+    // Allows consumer to access the underlying buffer even if the MemoryStream is created as a slice over another.
+    // Plain MemoryStream would throw "MemoryStream's internal buffer cannot be accessed."
+    internal class MemorySlice(MemoryStream other, int offset, int size)
+        : MemoryStream(other.GetBuffer(), offset, size, writable: false)
+    {
+        public readonly int Offset = offset;
+        public readonly byte[] FullBuffer = other.GetBuffer();
+    }
+}

src/Sentry.Android.AssemblyReader/V1/AndroidAssemblyDirectoryReaderV1.cs

@@ -26,7 +26,7 @@ public AndroidAssemblyDirectoryReaderV1(ZipArchive zip, IList<string> supportedA
 
         // We need a seekable stream for the PEReader (or even to check whether the DLL is compressed), so make a copy.
         var memStream = zipEntry.Extract();
-        return CreatePEReader(name, memStream, Logger);
+        return ArchiveUtils.CreatePEReader(name, memStream, Logger);
     }
 
     private ZipArchiveEntry? FindAssembly(string name)

src/Sentry.Android.AssemblyReader/V1/AndroidAssemblyStoreReaderV1.cs

@@ -29,7 +29,7 @@ public AndroidAssemblyStoreReaderV1(ZipArchive zip, IList<string> supportedAbis,
             return null;
         }
 
-        return CreatePEReader(name, stream, Logger);
+        return ArchiveUtils.CreatePEReader(name, stream, Logger);
     }
 
     private AssemblyStoreAssembly? TryFindAssembly(string name)
@@ -409,7 +409,7 @@ public AssemblyStoreReader(MemoryStream store, string? arch = null)
             assembly.ConfigDataOffset == 0 ? null : GetDataSlice(assembly.ConfigDataOffset, assembly.ConfigDataSize);
 
         private MemoryStream? GetDataSlice(uint offset, uint size) =>
-            size == 0 ? null : new MemorySlice(_storeData, (int)offset, (int)size);
+            size == 0 ? null : new ArchiveUtils.MemorySlice(_storeData, (int)offset, (int)size);
 
         public bool HasIdenticalContent(AssemblyStoreReader other)
         {

src/Sentry.Android.AssemblyReader/V2/AndroidAssemblyDirectoryReaderV2.cs

@@ -1,5 +1,3 @@
-using Sentry.Android.AssemblyReader.V2;
-
 namespace Sentry.Android.AssemblyReader.V2;
 
 // The "Old" app type - where each DLL is placed in the 'assemblies' directory as an individual file.
@@ -36,7 +34,7 @@ public AndroidAssemblyDirectoryReaderV2(string apkPath, IList<string> supportedA
             }
 
             Logger?.Invoke("Resolved assembly {0} in the APK", name);
-            return AndroidAssemblyReader.CreatePEReader(name, memStream, Logger);
+            return ArchiveUtils.CreatePEReader(name, memStream, Logger);
         }
 
         Logger?.Invoke("Couldn't find assembly {0} in the APK", name);

src/Sentry.Android.AssemblyReader/V2/AndroidAssemblyStoreReaderV2.cs

@@ -71,7 +71,7 @@ public static bool TryReadStore(string inputFile, IList<string> supportedAbis, D
             return null;
         }
 
-        return AndroidAssemblyReader.CreatePEReader(name, stream, _logger);
+        return ArchiveUtils.CreatePEReader(name, stream, _logger);
     }
 
     private ExplorerStoreItem? TryFindAssembly(string name)
@@ -115,17 +115,3 @@ public void Dispose()
         // No-op
     }
 }
-
-internal static class DeviceArchitectureExtensions
-{
-    public static AndroidTargetArch AbiToDeviceArchitecture(this string abi) =>
-        abi switch
-        {
-            "armeabi-v7a" => AndroidTargetArch.Arm,
-            "arm64-v8a" => AndroidTargetArch.Arm64,
-            "x86" => AndroidTargetArch.X86,
-            "x86_64" => AndroidTargetArch.X86_64,
-            "mips" => AndroidTargetArch.Mips,
-            _ => AndroidTargetArch.Other,
-        };
-}

src/Sentry.Android.AssemblyReader/V2/DeviceArchitectureExtensions.cs

@@ -0,0 +1,15 @@
+namespace Sentry.Android.AssemblyReader.V2;
+
+internal static class DeviceArchitectureExtensions
+{
+    public static AndroidTargetArch AbiToDeviceArchitecture(this string abi) =>
+        abi switch
+        {
+            "armeabi-v7a" => AndroidTargetArch.Arm,
+            "arm64-v8a" => AndroidTargetArch.Arm64,
+            "x86" => AndroidTargetArch.X86,
+            "x86_64" => AndroidTargetArch.X86_64,
+            "mips" => AndroidTargetArch.Mips,
+            _ => AndroidTargetArch.Other,
+        };
+}

test/Sentry.Android.AssemblyReader.Tests/AndroidAssemblyReaderTests.cs

@@ -1,3 +1,6 @@
+using Sentry.Android.AssemblyReader.V1;
+using Sentry.Android.AssemblyReader.V2;
+
 namespace Sentry.Android.AssemblyReader.Tests;
 
 public class AndroidAssemblyReaderTests
@@ -49,10 +52,10 @@
         switch (TargetFramework)
         {
             case "net9.0":
-                Assert.IsType<V2.AndroidAssemblyStoreReaderV2>(sut);
+                Assert.IsType<AndroidAssemblyStoreReaderV2>(sut);
                 break;
             case "net8.0":
-                Assert.IsType<V1.AndroidAssemblyStoreReaderV1>(sut);
+                Assert.IsType<AndroidAssemblyStoreReaderV1>(sut);
                 break;
             default:
                 throw new NotSupportedException($"Unsupported target framework: {TargetFramework}");
@@ -65,14 +68,14 @@
 #if ANDROID
         Skip.If(true, "It's unknown whether the current Android app APK is an assembly store or not.");
 #endif
         using var sut = GetSut(false, false, isCompressed: true);
         switch (TargetFramework)
         {
             case "net9.0":
-                Assert.IsType<V2.AndroidAssemblyDirectoryReaderV2>(sut);
+                Assert.IsType<AndroidAssemblyDirectoryReaderV2>(sut);
                 break;
             case "net8.0":
-                Assert.IsType<V1.AndroidAssemblyDirectoryReaderV1>(sut);
+                Assert.IsType<AndroidAssemblyDirectoryReaderV1>(sut);
                 break;
             default:
                 throw new NotSupportedException($"Unsupported target framework: {TargetFramework}");
@@ -109,7 +112,7 @@
         Skip.If(!isAssemblyStore);
         Skip.If(!isCompressed);
 #endif
         using var sut = GetSut(isAot, isAssemblyStore, isCompressed);
 
         var peReader = sut.TryReadAssembly(assemblyName);
         Assert.NotNull(peReader);

test/Sentry.Android.AssemblyReader.Tests/ApiApprovalTests.verify.cs

@@ -1,5 +1,3 @@
-using Sentry.Android.AssemblyReader.V1;
-
 namespace Sentry.Android.AssemblyReader.Tests;
 
 public class ApiApprovalTests