Merge pull request #24377 from Catfish-Man/string-from-file-benchmarks-reland

Add a benchmark for bridging String(contentsOfFile:...), now with ava…

Author: Catfish-Man

benchmark/single-source/ObjectiveCBridging.swift

@@ -73,6 +73,9 @@ public let ObjectiveCBridging = [
   BenchmarkInfo(name: "ObjectiveCBridgeFromNSDateComponents",
     runFunction: run_ObjectiveCBridgeFromNSDateComponents, tags: t,
     setUpFunction: setup_dateComponents),
+  BenchmarkInfo(name: "ObjectiveCBridgeASCIIStringFromFile",
+                runFunction: run_ASCIIStringFromFile, tags: ts,
+                setUpFunction: setup_ASCIIStringFromFile),
 ]
 
 #if _runtime(_ObjC)
@@ -709,3 +712,35 @@ public func run_ObjectiveCBridgeFromNSDateComponents(_ N: Int) {
   }
   #endif
 }
+
+var ASCIIStringFromFile:String? = nil
+public func setup_ASCIIStringFromFile() {
+  #if _runtime(_ObjC)
+  let url:URL
+  if #available(OSX 10.12, iOS 10.0, tvOS 10.0, watchOS 3.0, *) {
+    url = FileManager.default.temporaryDirectory.appendingPathComponent(
+      "sphinx.txt"
+    )
+  } else {
+    url = URL(fileURLWithPath: "/tmp/sphinx.txt")
+  }
+  var str = "Sphinx of black quartz judge my vow"
+  str = Array(repeating: str, count: 100).joined()
+  try? str.write(
+    to: url,
+    atomically: true,
+    encoding: .ascii
+  )
+  ASCIIStringFromFile = try! String(contentsOf: url, encoding: .ascii)
+  #endif
+}
+
+@inline(never)
+public func run_ASCIIStringFromFile(_ N: Int) {
+  #if _runtime(_ObjC)
+  for _ in 0 ..< N {
+    blackHole((ASCIIStringFromFile! + "").utf8.count)
+  }
+  #endif
+}
+