sentry-demos · armcknight · Jul 18, 2025
diff --git a/EmpowerPlant.xcodeproj/project.pbxproj b/EmpowerPlant.xcodeproj/project.pbxproj
@@ -7,6 +7,7 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		843226DB2E29E12C000311A4 /* SlowOperations.swift in Sources */ = {isa = PBXBuildFile; fileRef = 843226DA2E29E12C000311A4 /* SlowOperations.swift */; };
 		843BD60F2AD08CE900B0098F /* Utils.swift in Sources */ = {isa = PBXBuildFile; fileRef = 843BD60E2AD08CE900B0098F /* Utils.swift */; };
 		843BD6272AD7798C00B0098F /* jwt-deep-field.png in Resources */ = {isa = PBXBuildFile; fileRef = 843BD6262AD7798C00B0098F /* jwt-deep-field.png */; };
 		846BEA1C2ABE611A0032F77F /* mobydick.txt in Resources */ = {isa = PBXBuildFile; fileRef = 846BEA1B2ABE611A0032F77F /* mobydick.txt */; };
@@ -40,6 +41,7 @@
 
 /* Begin PBXFileReference section */
 		840B7EF12BBF3C70008B8120 /* .slather.yml */ = {isa = PBXFileReference; lastKnownFileType = text.yaml; path = .slather.yml; sourceTree = "<group>"; };
+		843226DA2E29E12C000311A4 /* SlowOperations.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SlowOperations.swift; sourceTree = "<group>"; };
 		843BD60E2AD08CE900B0098F /* Utils.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Utils.swift; sourceTree = "<group>"; };
 		843BD6262AD7798C00B0098F /* jwt-deep-field.png */ = {isa = PBXFileReference; lastKnownFileType = image.png; path = "jwt-deep-field.png"; sourceTree = "<group>"; };
 		846BEA1A2ABE46880032F77F /* upload-symbols.sh */ = {isa = PBXFileReference; lastKnownFileType = text.script.sh; path = "upload-symbols.sh"; sourceTree = "<group>"; };
@@ -130,6 +132,7 @@
 				843BD60E2AD08CE900B0098F /* Utils.swift */,
 				D15FCDA727E00F0D00258BF3 /* Model.xcdatamodeld */,
 				D17C73CB27D82EB8006650AF /* EmpowerPlantViewController.swift */,
+				843226DA2E29E12C000311A4 /* SlowOperations.swift */,
 				846BEA1B2ABE611A0032F77F /* mobydick.txt */,
 				D19EBE6E2805ED52007022DC /* ShoppingCart.swift */,
 				D17C73CE27D82ED1006650AF /* CartViewController.swift */,
@@ -283,6 +286,7 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				843226DB2E29E12C000311A4 /* SlowOperations.swift in Sources */,
 				D17C73CC27D82EB8006650AF /* EmpowerPlantViewController.swift in Sources */,
 				D17C73D227D83321006650AF /* ListAppViewController.swift in Sources */,
 				D15EDF14282BF80400FC13D6 /* Product+CoreDataClass.swift in Sources */,

diff --git a/EmpowerPlant.xcodeproj/xcshareddata/xcschemes/EmpowerPlant.xcscheme b/EmpowerPlant.xcodeproj/xcshareddata/xcschemes/EmpowerPlant.xcscheme
@@ -72,6 +72,10 @@
             argument = "--wipe-db"
             isEnabled = "NO">
          </CommandLineArgument>
+         <CommandLineArgument
+            argument = "--skip-slow-launch-work"
+            isEnabled = "NO">
+         </CommandLineArgument>
          <CommandLineArgument
             argument = "--no-debug-mode-in-debug-build"
             isEnabled = "YES">

diff --git a/EmpowerPlant/EmpowerPlantViewController.swift b/EmpowerPlant/EmpowerPlantViewController.swift
@@ -49,99 +49,31 @@ class EmpowerPlantViewController: UIViewController {
 
         getAllProductsFromServer()
         getAllProductsFromDb()
-        readCurrentDirectory()
-        performLongFileOperation()
         processProducts()
         checkRelease()
-
-
+
         NotificationCenter.default.addObserver(forName: modifiedDBNotificationName, object: nil, queue: nil) { _ in
             self.getAllProductsFromDb()
         }
     }
 
     override func viewDidAppear(_ animated: Bool) {
         super.viewDidAppear(animated)
+
+        if !ProcessInfo.processInfo.arguments.contains("--skip-slow-launch-work") {
+            SlowOperation.fileRead()
+            SlowOperation.fileWrite()
+        }
+
         SentrySDK.reportFullyDisplayed()
     }
-
-    func performLongFileOperation() {
-        let longString = String(repeating: UUID().uuidString, count: 5_000_000)
-        let data = longString.data(using: .utf8)!
-        let filePath = FileManager.default.temporaryDirectory.appendingPathComponent("tmp" + UUID().uuidString)
-        try! data.write(to: filePath)
-        try! FileManager.default.removeItem(at: filePath)
-    }
 
     func processProducts() {
         let span = SentrySDK.span?.startChild(operation: "product_processing")
-        _ = getIterator(42);
-        sleep(50 / 1000)
-        span?.finish()
-    }
-
-    func getIterator(_ n: Int) -> Int {
-       if (n <= 0) {
-           return 0;
-       }
-       if (n == 1 || n == 2) {
-           return 1;
-       }
-       return getIterator(n - 1) + getIterator(n - 2);
-   }
-
-
-    func readCurrentDirectory() {
-        let path = FileManager.default.currentDirectoryPath
-        do {
-            let items = try FileManager.default.contentsOfDirectory(atPath: path)
-            let loop = fibonacciSeries(num: items.count)
-            for i in 1...loop {
-                readDirectory(path: path)
-            }
-        } catch {
-            // TODO: error
-        }
-    }
-
-    func readDirectory(path: String) {
-        let fm = FileManager.default
-
-        do {
-            let items = try fm.contentsOfDirectory(atPath: path)
-
-            for item in items {
-                var isDirectory: ObjCBool = false
-                if fm.fileExists(atPath: item, isDirectory: &isDirectory) {
-                    readDirectory(path: item)
-                } else {
-                    return
-                }
-            }
-        } catch {
-            // TODO: error
+        if !ProcessInfo.processInfo.arguments.contains("--skip-slow-launch-work") {
+            SlowOperation.computation()
         }
-
-    }
-
-    func fibonacciSeries(num: Int) -> Int{
-        // The value of 0th and 1st number of the fibonacci series are 0 and 1
-        var n1 = 0
-        var n2 = 1
-
-        // To store the result
-        var nR = 0
-        // Adding two previous numbers to find ith number of the series
-        for _ in 0..<num{
-            nR = n1
-            n1 = n2
-            n2 = nR + n2
-        }
-
-        if (n1 < 500) {
-            return fibonacciSeries(num: n1)
-        }
-        return n1
+        span?.finish()
     }
 
     @objc

diff --git a/EmpowerPlant/SlowOperations.swift b/EmpowerPlant/SlowOperations.swift
@@ -0,0 +1,92 @@
+//
+//  SlowOperations.swift
+//  EmpowerPlant
+//
+//  Created by Andrew McKnight on 7/17/25.
+//
+
+import Foundation
+
+/// Utilities to simulate slow operations, to help demonstrate how Sentry can help pinpoint such issues in real apps.
+struct SlowOperation {
+    /// Simulate a long-running file write operation by building a large string and writing it to disk, then deleting it again.
+    static public func fileWrite() {
+        let longString = String(repeating: UUID().uuidString, count: 5_000_000)
+        let data = longString.data(using: .utf8)!
+        let filePath = FileManager.default.temporaryDirectory.appendingPathComponent("tmp" + UUID().uuidString)
+        try! data.write(to: filePath)
+        try! FileManager.default.removeItem(at: filePath)
+    }
+
+    /// Simulate a long-running file read operation by slowly calculate a number of times to iterate, then depth-first search a directory structure that many times.
+    static public func fileRead() {
+        let path = FileManager.default.currentDirectoryPath
+        do {
+            let items = try FileManager.default.contentsOfDirectory(atPath: path)
+            let loop = fibonacciSeries(num: items.count)
+            for _ in 1...loop {
+                readDirectory(path: path)
+            }
+        } catch {
+            // TODO: error
+        }
+    }
+
+    /// Simulate a long-running CPU-bound operation
+    static public func computation() {
+        _ = getIterator(42);
+        sleep(50 / 1000)
+    }
+}
+
+private extension SlowOperation {
+    static func readDirectory(path: String) {
+        let fm = FileManager.default
+
+        do {
+            let items = try fm.contentsOfDirectory(atPath: path)
+
+            for item in items {
+                var isDirectory: ObjCBool = false
+                // TODO: check the value of isDirectory after fileExists, unless we want the errors to happen when calling contentsOfDirectory on a path that's not a directory?
+                if fm.fileExists(atPath: item, isDirectory: &isDirectory) {
+                    readDirectory(path: item)
+                } else {
+                    return
+                }
+            }
+        } catch {
+            // TODO: error
+        }
+    }
+
+    static func fibonacciSeries(num: Int) -> Int{
+        // The value of 0th and 1st number of the fibonacci series are 0 and 1
+        var n1 = 0
+        var n2 = 1
+
+        // To store the result
+        var nR = 0
+        // Adding two previous numbers to find ith number of the series
+        for _ in 0..<num{
+            nR = n1
+            n1 = n2
+            n2 = nR + n2
+        }
+
+        if (n1 < 500) {
+            return fibonacciSeries(num: n1)
+        }
+        return n1
+    }
+
+    static func getIterator(_ n: Int) -> Int {
+       if (n <= 0) {
+           return 0;
+       }
+       if (n == 1 || n == 2) {
+           return 1;
+       }
+       return getIterator(n - 1) + getIterator(n - 2);
+    }
+}