Add Convert.FromHex benchmark (#3032)

* Added Convert.FromHex benchmark

* Update src/benchmarks/micro/libraries/System.Runtime.Extensions/Perf.Convert.cs

* Robustify downloading dotnet

---------

Co-authored-by: Dan Moseley <[email protected]>

Author: hrrrrustic

scripts/dotnet.py

@@ -778,29 +778,38 @@ def install(
     # Download appropriate dotnet install script
     dotnetInstallScriptExtension = '.ps1' if platform == 'win32' else '.sh'
     dotnetInstallScriptName = 'dotnet-install' + dotnetInstallScriptExtension
-    url = 'https://dot.net/v1/'  
+    url = 'https://dot.net/v1/'
     dotnetInstallScriptUrl = url + dotnetInstallScriptName
 
     dotnetInstallScriptPath = path.join(install_dir, dotnetInstallScriptName)
 
     getLogger().info('Downloading %s', dotnetInstallScriptUrl)
     count = 0
-    while count < 3:
+    max_count = 10
+    while count < max_count:
         try:
             with urlopen(dotnetInstallScriptUrl, context=ssl._create_unverified_context()) as response:
                 if "html" in response.info()['Content-Type']:
                     count = count + 1
-                    sleep(1) # sleep one second
+                    sleep(count ** 2)
                     continue
                 with open(dotnetInstallScriptPath, 'wb') as outfile:
                     outfile.write(response.read())
                     break
-        except Exception:
+        except URLError as error:
+            getLogger().warning(f"Could not download dotnet-install script from {dotnetInstallScriptUrl}; {Reason: {error.reason}}; Attempt {count}")
+            count = count + 1
+            sleep(count ** 2)
+            continue
+        except Exception as error:
+            getLogger().warning(f"Could not download dotnet-install script from {dotnetInstallScriptUrl}; {type(error).__name__}; Attempt {count}")
             count = count + 1
-            sleep(1)
+            sleep(count ** 2)
             continue
 
-    if count == 3:
+    getLogger().info(f"Downloaded {dotnetInstallScriptUrl} OK")
+
+    if count == max_count:
         getLogger().error("Fatal error: could not download dotnet-install script")
         raise Exception("Fatal error: could not download dotnet-install script")
 

src/benchmarks/micro/libraries/System.Runtime.Extensions/Perf.Convert.cs

@@ -1,4 +1,4 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
@@ -18,6 +18,9 @@ public class Perf_Convert
         private byte[] _binaryData;
         private char[] _base64CharArray;
         private string _base64String;
+#if NET5_0_OR_GREATER
+        private string _hexString;
+#endif
         private char[] _base64Chars;
 
         [GlobalSetup(Target = nameof(GetTypeCode))]
@@ -85,8 +88,16 @@ public void SetupToHexString()
             new Random(42).NextBytes(_binaryData);
         }
 
+        [GlobalSetup(Target = nameof(FromHexString))]
+        public void SetupFromHexString()
+        {
+            _hexString = Convert.ToHexString(Encoding.ASCII.GetBytes("This is a test of Convert."));   
+        }
+
         [Benchmark]
         public string ToHexString() => Convert.ToHexString(_binaryData);
+        [Benchmark]
+        public byte[] FromHexString() => Convert.FromHexString(_hexString);
 #endif
 
         private static byte[] InitializeBinaryDataCollection(int size)