(GH-943) Lock Pending File Until Operation Completes

Open and hold the pending file exclusively open until install is
finished. Then remove the file lock. This allows for better concurrent
operations when running multiple choco processes at the same time
(which isn't necessarily recommended).

src/chocolatey/infrastructure.app/services/ChocolateyPackageService.cs

@@ -50,6 +50,8 @@ public class ChocolateyPackageService : IChocolateyPackageService
         private readonly IAutomaticUninstallerService _autoUninstallerService;
         private readonly IXmlService _xmlService;
         private readonly IConfigTransformService _configTransformService;
+        private readonly IDictionary<string, FileStream> _pendingLocks = new Dictionary<string, FileStream>();
+
         private readonly IList<string> _proBusinessMessages = new List<string> {
 @"
 Are you ready for the ultimate experience? Check out Pro / Business! 
@@ -1158,6 +1160,7 @@ public void set_pending(PackageResult packageResult, ChocolateyConfiguration con
 
             var pendingFile = _fileSystem.combine_paths(packageDirectory, ApplicationParameters.PackagePendingFileName);
             _fileSystem.write_file(pendingFile, "{0}".format_with(packageResult.Name));
+           _pendingLocks.Add(packageResult.Name.to_lower(), _fileSystem.open_file_exclusive(pendingFile));
         }
 
         public void remove_pending(PackageResult packageResult, ChocolateyConfiguration config)
@@ -1177,6 +1180,15 @@ public void remove_pending(PackageResult packageResult, ChocolateyConfiguration
             }
 
             var pendingFile = _fileSystem.combine_paths(packageDirectory, ApplicationParameters.PackagePendingFileName);
+            var lockName = packageResult.Name.to_lower();
+            if (_pendingLocks.ContainsKey(lockName))
+            {
+                var fileLock = _pendingLocks[lockName];
+                _pendingLocks.Remove(lockName);
+                fileLock.Close();
+                fileLock.Dispose();
+            }
+
             if (_fileSystem.file_exists(pendingFile)) _fileSystem.delete_file(pendingFile);
         }
 

src/chocolatey/infrastructure.app/services/FilesService.cs

@@ -17,6 +17,7 @@ namespace chocolatey.infrastructure.app.services
 {
     using System;
     using System.IO;
+    using System.Linq;
     using configuration;
     using cryptography;
     using domain;
@@ -117,7 +118,7 @@ public PackageFiles capture_package_files(string directory, ChocolateyConfigurat
             this.Log().Debug(() => "Capturing package files in '{0}'".format_with(directory));
             //gather all files in the folder 
             var files = _fileSystem.get_files(directory, pattern: "*.*", option: SearchOption.AllDirectories);
-            foreach (string file in files.or_empty_list_if_null())
+            foreach (string file in files.or_empty_list_if_null().Where(f => !f.EndsWith(ApplicationParameters.PackagePendingFileName)))
             {
                 packageFiles.Files.Add(get_package_file(file));
             }