Utilizing a cache for user data

[StanleyGoldman]

Fixes: #412

Problems:

1. user data is not cached and queried for on demand
2. the object User has been used as a data object from GitClient

Solutions:

1. Introduce GitUser as the data object from GitClient
2. Use User much like Repository as the central front end to user data and actions
   1. User gets initialized with a GitClient and initiates a process to update it's data
   2. User listens to invalidation events from the GitUserCache and updates it's data
3. Remove vestiges of User and user data from Repository and RepositoryManager
4. Updating functionality in UserSettingsView and InitProviewView to use the new cache

Depends on:

• Adding functionality to GitClient to set user info #426
• Functionality to track "first run" in cache objects #434
• Changing GitClient to return User instead of string array #425
• A simpler data update method to avoid spamming GitClient #423
• SettingsView needs to check for null Repository #459
• Changing to a format string that is compatible with parse operations in Mono #460

[grokys]

Just to clarify as it's not clear from the title/description: this PR should only be caching user data?

[StanleyGoldman]

The title of this PR could be clearer, but yes, I added access to cache objects to GitClient, so that GitClient could cache and manager user data.

[StanleyGoldman]

I updated the description.

[grokys]

Got one question about event handlers preventing GC. Note this this also applies to Repository.

[grokys]

Will the User objects never need to be GCd? Adding these event handlers will mean that cacheContainer.GitUserCache will retain a reference to each User object.

[StanleyGoldman]

User and Repository are found on DefaultEnvironment.

Unity/src/GitHub.Api/Platform/IEnvironment.cs

Lines 30 to 31 in 2e16908

	IUser User { get; set; }
	IRepository Repository { get; set; }

Unity/src/GitHub.Api/Platform/DefaultEnvironment.cs

Lines 137 to 138 in 2e16908

	public IRepository Repository { get; set; }
	public IUser User { get; set; }

There is generally only one instance of User and Repository in the system created at specific points of initialization.

Unity/src/GitHub.Api/Platform/DefaultEnvironment.cs

Line 51 in 2e16908

User = new User(CacheContainer);

Unity/src/GitHub.Api/Platform/DefaultEnvironment.cs

Line 89 in 2e16908

Repository = new Repository(RepositoryPath, CacheContainer);

These objects are only "destroyed" when the domain reloads.

When they are constructed (either the first time or after a domain reload) these objects are being fed a CacheContainer. It will take a moment on some other threads for the User and Repository objects to get what they need to be fully functioning (they both have Initialize methods for that).

These objects store their data in file based caches specifically for this reason. Until they are fully functioning, they get to use their file based cache to supply data to the user interface.

[drguthals]

This looks good to me @StanleyGoldman - Just take a look at @grokys question above

[grokys]

👍