RUM-11460 More feedback

Author: gonzalezreal

DatadogSessionReplay/Sources/Recorder/ViewTreeSnapshotProducer/ViewTreeSnapshot/NodeRecorders/SwiftUI/ShapeResource.swift

@@ -7,10 +7,7 @@
 #if os(iOS)
 
 import SwiftUI
-
-#if canImport(CryptoKit)
-import CryptoKit
-#endif
+import CommonCrypto
 
 @available(iOS 13.0, *)
 internal final class ShapeResource: NSObject {
@@ -24,13 +21,11 @@ internal final class ShapeResource: NSObject {
     }
 
     private func makeIdentifier() -> String {
-#if canImport(CryptoKit)
-        let hash = Insecure.MD5.hash(data: self.data)
-        return hash.map { String(format: "%02hhx", $0) }.joined()
-#else
-        // Should never execute since CryptoKit is available iOS 13
-        fatalError("CryptoKit not available")
-#endif
+        var digest = [UInt8](repeating: 0, count: Int(CC_MD5_DIGEST_LENGTH))
+        self.data.withUnsafeBytes { buffer in
+            _ = CC_MD5(buffer.baseAddress, CC_LONG(buffer.count), &digest)
+        }
+        return digest.map { String(format: "%02hhx", $0) }.joined()
     }
 
     private func makeData() -> Data {

DatadogSessionReplay/Sources/Recorder/ViewTreeSnapshotProducer/ViewTreeSnapshot/NodeRecorders/SwiftUI/ShapeResourceBuilder.swift

@@ -9,8 +9,14 @@
 import Foundation
 import SwiftUI
 
+/// A performance-optimized builder for creating SVG-based shape resources from SwiftUI paths.
+///
+/// `ShapeResourceBuilder` implements a multi-level caching strategy to eliminate expensive
+/// recomputations during UI updates and scrolling animations. This addresses performance
+/// issues that can occur when the same shapes are rendered repeatedly in Session Replay.
 @available(iOS 13.0, *)
 internal final class ShapeResourceBuilder {
+    /// Cache key for SwiftUI path data, used to avoid redundant SVG path string generation.
     private class PathKey: NSObject {
         private let path: SwiftUI.Path
 
@@ -32,6 +38,7 @@ internal final class ShapeResourceBuilder {
         }
     }
 
+    /// Composite cache key for complete shape resources, incorporating all visual properties.
     private class ResourceKey: NSObject {
         private let path: SwiftUI.Path
         private let color: ResolvedPaint
@@ -71,14 +78,33 @@ internal final class ShapeResourceBuilder {
         }
     }
 
+    /// Cache for SVG path data strings, preventing redundant path-to-SVG conversions.
     private let pathCache = NSCache<PathKey, NSString>()
+
+    /// Cache for complete shape resources, avoiding full SVG generation and hashing.
     private let resourceCache = NSCache<ResourceKey, ShapeResource>()
 
     init() {
         pathCache.countLimit = 25
         resourceCache.countLimit = 50
     }
 
+    /// Creates or retrieves a cached SVG-based shape resource for the given parameters.
+    ///
+    /// Generated SVG follows this structure:
+    ///
+    /// ```xml
+    /// <svg width="100" height="100" xmlns="http://www.w3.org/2000/svg">
+    ///   <path d="M 10 10 L 90 90 Z" fill="#FF0000FF" fill-rule="nonzero"/>
+    /// </svg>
+    /// ```
+    ///
+    /// - Parameters:
+    ///   - path: The SwiftUI path defining the shape geometry
+    ///   - color: Resolved paint information including color and opacity
+    ///   - fillStyle: Fill style determining the fill rule (even-odd vs non-zero)
+    ///   - size: The target size for the SVG viewport
+    /// - Returns: A `ShapeResource` containing the complete SVG markup
     func shapeResource(
         for path: SwiftUI.Path,
         color: ResolvedPaint,
@@ -108,6 +134,13 @@ internal final class ShapeResourceBuilder {
         return resource
     }
 
+    /// Retrieves or generates SVG path data string for the given SwiftUI path.
+    ///
+    /// This method provides path-level caching to avoid expensive path-to-SVG conversion
+    /// when the same path geometry is used with different visual properties (colors, sizes).
+    ///
+    /// - Parameter path: The SwiftUI path to convert to SVG path data
+    /// - Returns: SVG path data string (e.g., "M 10 10 L 90 90 Z")
     private func pathData(for path: SwiftUI.Path) -> String {
         let key = PathKey(path)
 

DatadogSessionReplay/Tests/Recorder/ViewTreeSnapshotProducer/ViewTreeSnapshot/NodeRecorders/SwiftUI/ShapeResourceBuilderTests.swift

@@ -115,6 +115,23 @@ final class ShapeResourceBuilderTests: XCTestCase {
 
         XCTAssertFalse(firstResource === secondResource)
     }
+
+    func testIdentifierStability() {
+        // Given
+        let svgString = """
+            <svg width="50.000" height="50.000" xmlns="http://www.w3.org/2000/svg">
+              <path d="M 0.000 0.000 L 50.000 50.000" fill="#00000000" fill-rule="evenodd"/>
+            </svg>
+            """
+
+        // When
+        let firstResource = ShapeResource(svgString: svgString)
+        let secondResource = ShapeResource(svgString: svgString)
+
+        // Then
+        XCTAssertEqual(firstResource.calculateIdentifier(), "33102ea8ca2ccf8c37ba97cdb3391587")
+        XCTAssertEqual(firstResource.calculateIdentifier(), secondResource.calculateIdentifier())
+    }
 }
 
 #endif