RUM-1000 chore: improve telemetry messages for file I/O errors

DatadogCore/Sources/Core/Storage/FilesOrchestrator.swift

@@ -15,6 +15,7 @@ internal protocol FilesOrchestratorType: AnyObject {
     func delete(readableFile: ReadableFile, deletionReason: BatchDeletedMetric.RemovalReason)
 
     var ignoreFilesAgeWhenReading: Bool { get set }
+    var trackName: String { get }
 }
 
 /// Orchestrates files in a single directory.
@@ -52,6 +53,10 @@ internal class FilesOrchestrator: FilesOrchestratorType {
     /// An extra information to include in metrics or `nil` if metrics should not be reported for this orchestrator.
     let metricsData: MetricsData?
 
+    var trackName: String {
+        metricsData?.trackName ?? "Unknown"
+    }
+
     init(
         directory: Directory,
         performance: StoragePerformancePreset,

DatadogCore/Sources/Core/Storage/Writing/FileWriter.swift

@@ -37,25 +37,44 @@ internal struct FileWriter: Writer {
     ///  - value: Encodable value to write.
     ///  - metadata: Encodable metadata to write.
     func write<T: Encodable, M: Encodable>(value: T, metadata: M?) {
-        do {
-            var encoded: Data = .init()
-            if let metadata = metadata {
+        var encoded: Data = .init()
+        if let metadata = metadata {
+            do {
                 let encodedMetadata = try encode(value: metadata, blockType: .eventMetadata)
                 encoded.append(encodedMetadata)
+            } catch {
+                DD.logger.error("(\(orchestrator.trackName)) Failed to encode metadata", error: error)
+                telemetry.error("(\(orchestrator.trackName)) Failed to encode metadata", error: error)
             }
+        }
 
+        do {
             let encodedValue = try encode(value: value, blockType: .event)
             encoded.append(encodedValue)
+        } catch {
+            DD.logger.error("(\(orchestrator.trackName)) Failed to encode value", error: error)
+            telemetry.error("(\(orchestrator.trackName)) Failed to encode value", error: error)
+            return
+        }
 
-            // Make sure both event and event metadata are written to the same file.
-            // This is to avoid a situation where event is written to one file and event metadata to another.
-            // If this happens, the reader will not be able to match event with its metadata.
-            let writeSize = UInt64(encoded.count)
-            let file = try orchestrator.getWritableFile(writeSize: writeSize)
+        // Make sure both event and event metadata are written to the same file.
+        // This is to avoid a situation where event is written to one file and event metadata to another.
+        // If this happens, the reader will not be able to match event with its metadata.
+        let writeSize = UInt64(encoded.count)
+        let file: WritableFile
+        do {
+            file = try orchestrator.getWritableFile(writeSize: writeSize)
+        } catch {
+            DD.logger.error("(\(orchestrator.trackName)) Failed to get writable file for \(writeSize) bytes", error: error)
+            telemetry.error("(\(orchestrator.trackName)) Failed to get writable file for \(writeSize) bytes", error: error)
+            return
+        }
+
+        do {
             try file.append(data: encoded)
         } catch {
-            DD.logger.error("Failed to write data", error: error)
-            telemetry.error("Failed to write data to file", error: error)
+            DD.logger.error("(\(orchestrator.trackName)) Failed to write \(writeSize) bytes to file", error: error)
+            telemetry.error("(\(orchestrator.trackName)) Failed to write \(writeSize) bytes to file", error: error)
         }
     }
 

DatadogCore/Tests/Datadog/Core/Persistence/Writing/FileWriterTests.swift

@@ -149,7 +149,8 @@ class FileWriterTests: XCTestCase {
                     maxObjectSize: 23 // 23 bytes is enough for TLV with {"key1":"value1"} JSON
                 ),
                 dateProvider: SystemDateProvider(),
-                telemetry: NOPTelemetry()
+                telemetry: NOPTelemetry(),
+                metricsData: .init(trackName: "rum", consentLabel: .mockAny(), uploaderPerformance: UploadPerformanceMock.noOp)
             ),
             encryption: nil,
             telemetry: NOPTelemetry()
@@ -168,7 +169,7 @@ class FileWriterTests: XCTestCase {
         reader = try BatchDataBlockReader(input: directory.files()[0].stream())
         blocks = try XCTUnwrap(reader.all())
         XCTAssertEqual(blocks.count, 1) // same content as before
-        XCTAssertEqual(dd.logger.errorLog?.message, "Failed to write data")
+        XCTAssertEqual(dd.logger.errorLog?.message, "(rum) Failed to encode value")
         XCTAssertEqual(dd.logger.errorLog?.error?.message, "DataBlock length exceeds limit of 23 bytes")
     }
 
@@ -181,15 +182,16 @@ class FileWriterTests: XCTestCase {
                 directory: directory,
                 performance: PerformancePreset.mockAny(),
                 dateProvider: SystemDateProvider(),
-                telemetry: NOPTelemetry()
+                telemetry: NOPTelemetry(),
+                metricsData: .init(trackName: "rum", consentLabel: .mockAny(), uploaderPerformance: UploadPerformanceMock.noOp)
             ),
             encryption: nil,
             telemetry: NOPTelemetry()
         )
 
         writer.write(value: FailingEncodableMock(errorMessage: "failed to encode `FailingEncodable`."))
 
-        XCTAssertEqual(dd.logger.errorLog?.message, "Failed to write data")
+        XCTAssertEqual(dd.logger.errorLog?.message, "(rum) Failed to encode value")
         XCTAssertEqual(dd.logger.errorLog?.error?.message, "failed to encode `FailingEncodable`.")
     }
 
@@ -202,7 +204,8 @@ class FileWriterTests: XCTestCase {
                 directory: directory,
                 performance: PerformancePreset.mockAny(),
                 dateProvider: SystemDateProvider(),
-                telemetry: NOPTelemetry()
+                telemetry: NOPTelemetry(),
+                metricsData: .init(trackName: "rum", consentLabel: .mockAny(), uploaderPerformance: UploadPerformanceMock.noOp)
             ),
             encryption: nil,
             telemetry: NOPTelemetry()
@@ -213,7 +216,7 @@ class FileWriterTests: XCTestCase {
         writer.write(value: ["won't be written"])
         try? directory.files()[0].makeReadWrite()
 
-        XCTAssertEqual(dd.logger.errorLog?.message, "Failed to write data")
+        XCTAssertEqual(dd.logger.errorLog?.message, "(rum) Failed to write 26 bytes to file")
         XCTAssertTrue(dd.logger.errorLog!.error!.message.contains("You don’t have permission"))
     }
 

DatadogCore/Tests/Datadog/Mocks/CoreMocks.swift

@@ -270,6 +270,7 @@ internal class NOPFilesOrchestrator: FilesOrchestratorType {
     func delete(readableFile: ReadableFile, deletionReason: BatchDeletedMetric.RemovalReason) { }
 
     var ignoreFilesAgeWhenReading = false
+    var trackName: String = "nop"
 }
 
 extension DataFormat {