Files
Umbraco-CMS/src/Umbraco.Core/Scoping/Scope.cs
2017-04-28 11:26:41 +02:00

514 lines
18 KiB
C#

using System;
using System.Data;
using Umbraco.Core.Cache;
using Umbraco.Core.Configuration;
using Umbraco.Core.Events;
using Umbraco.Core.IO;
using Umbraco.Core.Persistence;
namespace Umbraco.Core.Scoping
{
/// <summary>
/// Implements <see cref="IScope"/>.
/// </summary>
/// <remarks>Not thread-safe obviously.</remarks>
internal class Scope : IScopeInternal
{
private readonly ScopeProvider _scopeProvider;
private readonly IsolationLevel _isolationLevel;
private readonly RepositoryCacheMode _repositoryCacheMode;
private readonly bool? _scopeFileSystem;
private readonly ScopeContext _scopeContext;
private bool _callContext;
private bool _disposed;
private bool? _completed;
private IsolatedRuntimeCache _isolatedRuntimeCache;
private UmbracoDatabase _database;
private EventMessages _messages;
private ICompletable _fscope;
private IEventDispatcher _eventDispatcher;
// this is v7, in v8 this has to change to RepeatableRead
private const IsolationLevel DefaultIsolationLevel = IsolationLevel.ReadCommitted;
// initializes a new scope
private Scope(ScopeProvider scopeProvider,
Scope parent, ScopeContext scopeContext, bool detachable,
IsolationLevel isolationLevel = IsolationLevel.Unspecified,
RepositoryCacheMode repositoryCacheMode = RepositoryCacheMode.Unspecified,
IEventDispatcher eventDispatcher = null,
bool? scopeFileSystems = null,
bool callContext = false)
{
_scopeProvider = scopeProvider;
_scopeContext = scopeContext;
_isolationLevel = isolationLevel;
_repositoryCacheMode = repositoryCacheMode;
_eventDispatcher = eventDispatcher;
_scopeFileSystem = scopeFileSystems;
_callContext = callContext;
Detachable = detachable;
#if DEBUG_SCOPES
_scopeProvider.RegisterScope(this);
Console.WriteLine("create " + _instanceId.ToString("N").Substring(0, 8));
#endif
if (detachable)
{
if (parent != null) throw new ArgumentException("Cannot set parent on detachable scope.", "parent");
if (scopeContext != null) throw new ArgumentException("Cannot set context on detachable scope.", "scopeContext");
// detachable creates its own scope context
_scopeContext = new ScopeContext();
// see note below
if (scopeFileSystems == true)
_fscope = FileSystemProviderManager.Current.Shadow(Guid.NewGuid());
return;
}
if (parent != null)
{
ParentScope = parent;
// cannot specify a different mode!
if (repositoryCacheMode != RepositoryCacheMode.Unspecified && parent.RepositoryCacheMode != repositoryCacheMode)
throw new ArgumentException("Cannot be different from parent.", "repositoryCacheMode");
// cannot specify a dispatcher!
if (_eventDispatcher != null)
throw new ArgumentException("Cannot be specified on nested scope.", "eventDispatcher");
// cannot specify a different fs scope!
if (scopeFileSystems != null && parent._scopeFileSystem != scopeFileSystems)
throw new ArgumentException("Cannot be different from parent.", "scopeFileSystems");
}
else
{
// the FS scope cannot be "on demand" like the rest, because we would need to hook into
// every scoped FS to trigger the creation of shadow FS "on demand", and that would be
// pretty pointless since if scopeFileSystems is true, we *know* we want to shadow
if (scopeFileSystems == true)
_fscope = FileSystemProviderManager.Current.Shadow(Guid.NewGuid());
}
}
// initializes a new scope
public Scope(ScopeProvider scopeProvider, bool detachable,
ScopeContext scopeContext,
IsolationLevel isolationLevel = IsolationLevel.Unspecified,
RepositoryCacheMode repositoryCacheMode = RepositoryCacheMode.Unspecified,
IEventDispatcher eventDispatcher = null,
bool? scopeFileSystems = null,
bool callContext = false)
: this(scopeProvider, null, scopeContext, detachable, isolationLevel, repositoryCacheMode, eventDispatcher, scopeFileSystems, callContext)
{ }
// initializes a new scope in a nested scopes chain, with its parent
public Scope(ScopeProvider scopeProvider, Scope parent,
IsolationLevel isolationLevel = IsolationLevel.Unspecified,
RepositoryCacheMode repositoryCacheMode = RepositoryCacheMode.Unspecified,
IEventDispatcher eventDispatcher = null,
bool? scopeFileSystems = null,
bool callContext = false)
: this(scopeProvider, parent, null, false, isolationLevel, repositoryCacheMode, eventDispatcher, scopeFileSystems, callContext)
{ }
// initializes a new scope, replacing a NoScope instance
public Scope(ScopeProvider scopeProvider, NoScope noScope,
ScopeContext scopeContext,
IsolationLevel isolationLevel = IsolationLevel.Unspecified,
RepositoryCacheMode repositoryCacheMode = RepositoryCacheMode.Unspecified,
IEventDispatcher eventDispatcher = null,
bool? scopeFileSystems = null,
bool callContext = false)
: this(scopeProvider, null, scopeContext, false, isolationLevel, repositoryCacheMode, eventDispatcher, scopeFileSystems, callContext)
{
// steal everything from NoScope
_database = noScope.DatabaseOrNull;
_messages = noScope.MessagesOrNull;
// make sure the NoScope can be replaced ie not in a transaction
if (_database != null && _database.InTransaction)
throw new Exception("NoScope instance is not free.");
}
private readonly Guid _instanceId = Guid.NewGuid();
public Guid InstanceId { get { return _instanceId; } }
// a value indicating whether to force call-context
public bool CallContext
{
get
{
if (_callContext) return true;
if (ParentScope != null) return ParentScope.CallContext;
return false;
}
set { _callContext = value; }
}
public bool ScopedFileSystems
{
get
{
if (ParentScope != null) return ParentScope.ScopedFileSystems;
return _fscope != null;
}
}
/// <inheritdoc />
public RepositoryCacheMode RepositoryCacheMode
{
get
{
if (_repositoryCacheMode != RepositoryCacheMode.Unspecified) return _repositoryCacheMode;
if (ParentScope != null) return ParentScope.RepositoryCacheMode;
return RepositoryCacheMode.Default;
}
}
/// <inheritdoc />
public IsolatedRuntimeCache IsolatedRuntimeCache
{
get
{
if (ParentScope != null) return ParentScope.IsolatedRuntimeCache;
return _isolatedRuntimeCache ?? (_isolatedRuntimeCache
= new IsolatedRuntimeCache(type => new DeepCloneRuntimeCacheProvider(new ObjectCacheRuntimeCacheProvider())));
}
}
// a value indicating whether the scope is detachable
// ie whether it was created by CreateDetachedScope
public bool Detachable { get; private set; }
// the parent scope (in a nested scopes chain)
public IScopeInternal ParentScope { get; set; }
public bool Attached { get; set; }
// the original scope (when attaching a detachable scope)
public IScopeInternal OrigScope { get; set; }
// the original context (when attaching a detachable scope)
public ScopeContext OrigContext { get; set; }
// the context (for attaching & detaching only)
public ScopeContext Context
{
get { return _scopeContext; }
}
public IsolationLevel IsolationLevel
{
get
{
if (_isolationLevel != IsolationLevel.Unspecified) return _isolationLevel;
if (ParentScope != null) return ParentScope.IsolationLevel;
return DefaultIsolationLevel;
}
}
/// <inheritdoc />
public UmbracoDatabase Database
{
get
{
EnsureNotDisposed();
if (ParentScope != null)
{
var database = ParentScope.Database;
if (_isolationLevel > IsolationLevel.Unspecified && database.CurrentTransactionIsolationLevel < _isolationLevel)
throw new Exception("Scope requires isolation level " + _isolationLevel + ", but got " + database.CurrentTransactionIsolationLevel + " from parent.");
_database = database;
}
if (_database != null)
{
// if the database has been created by a Scope instance it has to be
// in a transaction, however it can be a database that was stolen from
// a NoScope instance, in which case we need to enter a transaction, as
// a scope implies a transaction, always
if (_database.InTransaction)
return _database;
}
else
{
// create a new database
_database = _scopeProvider.DatabaseFactory.CreateNewDatabase();
}
// enter a transaction, as a scope implies a transaction, always
try
{
_database.BeginTransaction(IsolationLevel);
return _database;
}
catch
{
_database.Dispose();
_database = null;
throw;
}
}
}
public UmbracoDatabase DatabaseOrNull
{
get
{
EnsureNotDisposed();
return ParentScope == null ? _database : ParentScope.DatabaseOrNull;
}
}
/// <inheritdoc />
public EventMessages Messages
{
get
{
EnsureNotDisposed();
if (ParentScope != null) return ParentScope.Messages;
if (_messages != null) return _messages;
// this is ugly - in v7 for backward compatibility reasons, EventMessages need
// to survive way longer that the scopes, and kinda resides on its own in http
// context, but must also be in scopes for when we do async and lose http context
// TODO refactor in v8
var factory = ScopeLifespanMessagesFactory.Current;
if (factory == null)
{
_messages = new EventMessages();
}
else
{
_messages = factory.GetFromHttpContext();
if (_messages == null)
factory.Set(_messages = new EventMessages());
}
return _messages;
}
}
public EventMessages MessagesOrNull
{
get
{
EnsureNotDisposed();
if (ParentScope != null) return ParentScope.MessagesOrNull;
// see comments in Messages
if (_messages != null) return _messages;
var factory = ScopeLifespanMessagesFactory.Current;
return factory == null ? null : factory.GetFromHttpContext();
}
}
/// <inheritdoc />
public IEventDispatcher Events
{
get
{
EnsureNotDisposed();
if (ParentScope != null) return ParentScope.Events;
return _eventDispatcher ?? (_eventDispatcher = new ScopeEventDispatcher());
}
}
/// <inheritdoc />
public bool Complete()
{
if (_completed.HasValue == false)
_completed = true;
return _completed.Value;
}
public void Reset()
{
_completed = null;
}
public void ChildCompleted(bool? completed)
{
// if child did not complete we cannot complete
if (completed.HasValue == false || completed.Value == false)
{
if (LogUncompletedScopes)
Logging.LogHelper.Debug<Scope>("Uncompleted Child Scope at\r\n" + Environment.StackTrace);
_completed = false;
}
}
private void EnsureNotDisposed()
{
if (_disposed)
throw new ObjectDisposedException("this");
}
public void Dispose()
{
EnsureNotDisposed();
if (this != _scopeProvider.AmbientScope)
{
#if DEBUG_SCOPES
var ambient = _scopeProvider.AmbientScope;
Logging.LogHelper.Debug<Scope>("Dispose error (" + (ambient == null ? "no" : "other") + " ambient)");
if (ambient == null)
throw new InvalidOperationException("Not the ambient scope (no ambient scope).");
var infos = _scopeProvider.GetScopeInfo(ambient);
throw new InvalidOperationException("Not the ambient scope (see current ambient ctor stack trace).\r\n" + infos.CtorStack);
#else
throw new InvalidOperationException("Not the ambient scope.");
#endif
}
var parent = ParentScope;
_scopeProvider.AmbientScope = parent;
#if DEBUG_SCOPES
_scopeProvider.Disposed(this);
#endif
if (parent != null)
parent.ChildCompleted(_completed);
else
DisposeLastScope();
_disposed = true;
GC.SuppressFinalize(this);
}
private void DisposeLastScope()
{
// figure out completed
var completed = _completed.HasValue && _completed.Value;
// deal with database
var databaseException = false;
if (_database != null)
{
try
{
if (completed)
_database.CompleteTransaction();
else
_database.AbortTransaction();
}
catch
{
databaseException = true;
throw;
}
finally
{
_database.Dispose();
_database = null;
if (databaseException)
RobustExit(false, true);
}
}
RobustExit(completed, false);
}
// this chains some try/finally blocks to
// - complete and dispose the scoped filesystems
// - deal with events if appropriate
// - remove the scope context if it belongs to this scope
// - deal with detachable scopes
// here,
// - completed indicates whether the scope has been completed
// can be true or false, but in both cases the scope is exiting
// in a normal way
// - onException indicates whether completing/aborting the database
// transaction threw an exception, in which case 'completed' has
// to be false + events don't trigger and we just to some cleanup
// to ensure we don't leave a scope around, etc
private void RobustExit(bool completed, bool onException)
{
if (onException) completed = false;
TryFinally(() =>
{
if (_scopeFileSystem == true)
{
if (completed)
_fscope.Complete();
_fscope.Dispose();
_fscope = null;
}
}, () =>
{
// deal with events
if (onException == false && _eventDispatcher != null)
_eventDispatcher.ScopeExit(completed);
}, () =>
{
// if *we* created it, then get rid of it
if (_scopeProvider.AmbientContext == _scopeContext)
{
try
{
_scopeProvider.AmbientContext.ScopeExit(completed);
}
finally
{
// removes the ambient context (ambient scope already gone)
_scopeProvider.SetAmbient(null);
}
}
}, () =>
{
if (Detachable)
{
// get out of the way, restore original
_scopeProvider.SetAmbient(OrigScope, OrigContext);
Attached = false;
OrigScope = null;
OrigContext = null;
}
});
}
private static void TryFinally(params Action[] actions)
{
TryFinally(0, actions);
}
private static void TryFinally(int index, Action[] actions)
{
if (index == actions.Length) return;
try
{
actions[index]();
}
finally
{
TryFinally(index + 1, actions);
}
}
// backing field for LogUncompletedScopes
private static bool? _logUncompletedScopes;
// caching config
// true if Umbraco.CoreDebug.LogUncompletedScope appSetting is set to "true"
private static bool LogUncompletedScopes
{
get { return (_logUncompletedScopes ?? (_logUncompletedScopes = UmbracoConfig.For.CoreDebug().LogUncompletedScopes)).Value; }
}
}
}