* GitVersionCache.cs refactoring: improved readibility

Author: sergiorykov

src/GitVersionCore/GitVersionCache.cs

@@ -1,13 +1,12 @@
 namespace GitVersion
 {
+    using GitVersion.Helpers;
     using System;
     using System.Collections.Generic;
     using System.IO;
     using System.Linq;
     using System.Security.Cryptography;
     using System.Text;
-    using GitVersion.Helpers;
-    using LibGit2Sharp;
     using YamlDotNet.Serialization;
 
     public class GitVersionCache
@@ -47,7 +46,7 @@ public void WriteVariablesToDiskCache(GitPreparer gitPreparer, VersionVariables
         private string PrepareCacheDirectory(GitPreparer gitPreparer)
         {
             var gitDir = gitPreparer.GetDotGitDirectory();
-            
+
             // If the cacheDir already exists, CreateDirectory just won't do anything (it won't fail). @asbjornu
             var cacheDir = GetCacheDir(gitDir);
             fileSystem.CreateDirectory(cacheDir);
@@ -62,51 +61,52 @@ public VersionVariables LoadVersionVariablesFromDiskCache(GitPreparer gitPrepare
                 var cacheDir = PrepareCacheDirectory(gitPreparer);
 
                 var cacheFileName = GetCacheFileName(GetKey(gitPreparer), cacheDir);
-                VersionVariables vv = null;
-                if (fileSystem.Exists(cacheFileName))
+                if (!fileSystem.Exists(cacheFileName))
+                {
+                    Logger.WriteInfo("Cache file " + cacheFileName + " not found.");
+                    return null;
+                }
+
+                using (Logger.IndentLog("Deserializing version variables from cache file " + cacheFileName))
                 {
-                    using (Logger.IndentLog("Deserializing version variables from cache file " + cacheFileName))
+                    try
                     {
+                        var loadedVariables = VersionVariables.FromFile(cacheFileName, fileSystem);
+                        return loadedVariables;
+                    }
+                    catch (Exception ex)
+                    {
+                        Logger.WriteWarning("Unable to read cache file " + cacheFileName + ", deleting it.");
+                        Logger.WriteInfo(ex.ToString());
                         try
                         {
-                            vv = VersionVariables.FromFile(cacheFileName, fileSystem);
+                            fileSystem.Delete(cacheFileName);
                         }
-                        catch (Exception ex)
+                        catch (Exception deleteEx)
                         {
-                            Logger.WriteWarning("Unable to read cache file " + cacheFileName + ", deleting it.");
-                            Logger.WriteInfo(ex.ToString());
-                            try
-                            {
-                                fileSystem.Delete(cacheFileName);
-                            }
-                            catch (Exception deleteEx)
-                            {
-                                Logger.WriteWarning(string.Format("Unable to delete corrupted version cache file {0}. Got {1} exception.", cacheFileName, deleteEx.GetType().FullName));
-                            }
+                            Logger.WriteWarning(string.Format("Unable to delete corrupted version cache file {0}. Got {1} exception.", cacheFileName, deleteEx.GetType().FullName));
                         }
+
+                        return null;
                     }
                 }
-                else
-                {
-                    Logger.WriteInfo("Cache file " + cacheFileName + " not found.");
-                }
-
-                return vv;
             }
         }
 
         string GetKey(GitPreparer gitPreparer)
         {
-            var gitDir = gitPreparer.GetDotGitDirectory();
+            var dotGitDirectory = gitPreparer.GetDotGitDirectory();
 
             // Maybe using timestamp in .git/refs directory is enough?
-            var ticks = fileSystem.GetLastDirectoryWrite(Path.Combine(gitDir, "refs"));
+            var lastGitRefsChangedTicks = fileSystem.GetLastDirectoryWrite(Path.Combine(dotGitDirectory, "refs"));
 
-            var configPath = ConfigurationProvider.SelectConfigFilePath(gitPreparer, fileSystem);
-            var configText = fileSystem.Exists(configPath) ? fileSystem.ReadAllText(configPath) : null;
-            var configHash = configText != null ? GetHash(configText) : null;
+            // will return the same hash even when config file will be moved 
+            // from workingDirectory to rootProjectDirectory. It's OK. Config essentially is the same.
+            var configFilePath = ConfigurationProvider.SelectConfigFilePath(gitPreparer, fileSystem);
+            var configFileContent = fileSystem.Exists(configFilePath) ? fileSystem.ReadAllText(configFilePath) : null;
+            var configFileHash = configFileContent != null ? GetHash(configFileContent) : null;
 
-            return gitPreparer.WithRepository(repo => string.Join(":", gitDir, repo.Head.CanonicalName, repo.Head.Tip.Sha, ticks, configHash));
+            return gitPreparer.WithRepository(repo => string.Join(":", dotGitDirectory, repo.Head.CanonicalName, repo.Head.Tip.Sha, lastGitRefsChangedTicks, configFileHash));
         }
 
         static string GetCacheFileName(string key, string cacheDir)
@@ -131,4 +131,4 @@ static string GetHash(string textToHash)
             }
         }
     }
-}
+}