mirror of
https://github.com/opencv/opencv.git
synced 2024-11-28 13:10:12 +08:00
482 lines
18 KiB
C++
482 lines
18 KiB
C++
//*********************************************************
|
|
//
|
|
// Copyright (c) Microsoft. All rights reserved.
|
|
// THIS CODE IS PROVIDED *AS IS* WITHOUT WARRANTY OF
|
|
// ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING ANY
|
|
// IMPLIED WARRANTIES OF FITNESS FOR A PARTICULAR
|
|
// PURPOSE, MERCHANTABILITY, OR NON-INFRINGEMENT.
|
|
//
|
|
//*********************************************************
|
|
|
|
//
|
|
// SuspensionManager.cpp
|
|
// Implementation of the SuspensionManager class
|
|
//
|
|
|
|
#include "pch.h"
|
|
#include "SuspensionManager.h"
|
|
|
|
#include <collection.h>
|
|
#include <algorithm>
|
|
|
|
using namespace SDKSample::Common;
|
|
|
|
using namespace Concurrency;
|
|
using namespace Platform;
|
|
using namespace Platform::Collections;
|
|
using namespace Windows::Foundation;
|
|
using namespace Windows::Foundation::Collections;
|
|
using namespace Windows::Storage;
|
|
using namespace Windows::Storage::FileProperties;
|
|
using namespace Windows::Storage::Streams;
|
|
using namespace Windows::UI::Xaml;
|
|
using namespace Windows::UI::Xaml::Controls;
|
|
using namespace Windows::UI::Xaml::Interop;
|
|
|
|
namespace
|
|
{
|
|
Map<String^, Object^>^ _sessionState = ref new Map<String^, Object^>();
|
|
String^ sessionStateFilename = "_sessionState.dat";
|
|
|
|
// Forward declarations for object object read / write support
|
|
void WriteObject(Windows::Storage::Streams::DataWriter^ writer, Platform::Object^ object);
|
|
Platform::Object^ ReadObject(Windows::Storage::Streams::DataReader^ reader);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Provides access to global session state for the current session. This state is serialized by
|
|
/// <see cref="SaveAsync"/> and restored by <see cref="RestoreAsync"/> which require values to be
|
|
/// one of the following: boxed values including integers, floating-point singles and doubles,
|
|
/// wide characters, boolean, Strings and Guids, or Map<String^, Object^> where map values are
|
|
/// subject to the same constraints. Session state should be as compact as possible.
|
|
/// </summary>
|
|
IMap<String^, Object^>^ SuspensionManager::SessionState::get(void)
|
|
{
|
|
return _sessionState;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Wrap a WeakReference as a reference object for use in a collection.
|
|
/// </summary>
|
|
private ref class WeakFrame sealed
|
|
{
|
|
private:
|
|
WeakReference _frameReference;
|
|
|
|
internal:
|
|
WeakFrame(Frame^ frame) { _frameReference = frame; }
|
|
property Frame^ ResolvedFrame
|
|
{
|
|
Frame^ get(void) { return _frameReference.Resolve<Frame>(); }
|
|
};
|
|
};
|
|
|
|
namespace
|
|
{
|
|
std::vector<WeakFrame^> _registeredFrames;
|
|
DependencyProperty^ FrameSessionStateKeyProperty =
|
|
DependencyProperty::RegisterAttached("_FrameSessionStateKeyProperty",
|
|
TypeName(String::typeid), TypeName(SuspensionManager::typeid), nullptr);
|
|
DependencyProperty^ FrameSessionStateProperty =
|
|
DependencyProperty::RegisterAttached("_FrameSessionStateProperty",
|
|
TypeName(IMap<String^, Object^>::typeid), TypeName(SuspensionManager::typeid), nullptr);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Registers a <see cref="Frame"/> instance to allow its navigation history to be saved to
|
|
/// and restored from <see cref="SessionState"/>. Frames should be registered once
|
|
/// immediately after creation if they will participate in session state management. Upon
|
|
/// registration if state has already been restored for the specified key
|
|
/// the navigation history will immediately be restored. Subsequent invocations of
|
|
/// <see cref="RestoreAsync(String)"/> will also restore navigation history.
|
|
/// </summary>
|
|
/// <param name="frame">An instance whose navigation history should be managed by
|
|
/// <see cref="SuspensionManager"/></param>
|
|
/// <param name="sessionStateKey">A unique key into <see cref="SessionState"/> used to
|
|
/// store navigation-related information.</param>
|
|
void SuspensionManager::RegisterFrame(Frame^ frame, String^ sessionStateKey)
|
|
{
|
|
if (frame->GetValue(FrameSessionStateKeyProperty) != nullptr)
|
|
{
|
|
throw ref new FailureException("Frames can only be registered to one session state key");
|
|
}
|
|
|
|
if (frame->GetValue(FrameSessionStateProperty) != nullptr)
|
|
{
|
|
throw ref new FailureException("Frames must be either be registered before accessing frame session state, or not registered at all");
|
|
}
|
|
|
|
// Use a dependency property to associate the session key with a frame, and keep a list of frames whose
|
|
// navigation state should be managed
|
|
frame->SetValue(FrameSessionStateKeyProperty, sessionStateKey);
|
|
_registeredFrames.insert(_registeredFrames.begin(), ref new WeakFrame(frame));
|
|
|
|
// Check to see if navigation state can be restored
|
|
RestoreFrameNavigationState(frame);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Disassociates a <see cref="Frame"/> previously registered by <see cref="RegisterFrame"/>
|
|
/// from <see cref="SessionState"/>. Any navigation state previously captured will be
|
|
/// removed.
|
|
/// </summary>
|
|
/// <param name="frame">An instance whose navigation history should no longer be
|
|
/// managed.</param>
|
|
void SuspensionManager::UnregisterFrame(Frame^ frame)
|
|
{
|
|
// Remove session state and remove the frame from the list of frames whose navigation
|
|
// state will be saved (along with any weak references that are no longer reachable)
|
|
auto key = safe_cast<String^>(frame->GetValue(FrameSessionStateKeyProperty));
|
|
if (SessionState->HasKey(key)) SessionState->Remove(key);
|
|
_registeredFrames.erase(
|
|
std::remove_if(_registeredFrames.begin(), _registeredFrames.end(), [=](WeakFrame^& e)
|
|
{
|
|
auto testFrame = e->ResolvedFrame;
|
|
return testFrame == nullptr || testFrame == frame;
|
|
}),
|
|
_registeredFrames.end()
|
|
);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Provides storage for session state associated with the specified <see cref="Frame"/>.
|
|
/// Frames that have been previously registered with <see cref="RegisterFrame"/> have
|
|
/// their session state saved and restored automatically as a part of the global
|
|
/// <see cref="SessionState"/>. Frames that are not registered have transient state
|
|
/// that can still be useful when restoring pages that have been discarded from the
|
|
/// navigation cache.
|
|
/// </summary>
|
|
/// <remarks>Apps may choose to rely on <see cref="LayoutAwarePage"/> to manage
|
|
/// page-specific state instead of working with frame session state directly.</remarks>
|
|
/// <param name="frame">The instance for which session state is desired.</param>
|
|
/// <returns>A collection of state subject to the same serialization mechanism as
|
|
/// <see cref="SessionState"/>.</returns>
|
|
IMap<String^, Object^>^ SuspensionManager::SessionStateForFrame(Frame^ frame)
|
|
{
|
|
auto frameState = safe_cast<IMap<String^, Object^>^>(frame->GetValue(FrameSessionStateProperty));
|
|
|
|
if (frameState == nullptr)
|
|
{
|
|
auto frameSessionKey = safe_cast<String^>(frame->GetValue(FrameSessionStateKeyProperty));
|
|
if (frameSessionKey != nullptr)
|
|
{
|
|
// Registered frames reflect the corresponding session state
|
|
if (!_sessionState->HasKey(frameSessionKey))
|
|
{
|
|
_sessionState->Insert(frameSessionKey, ref new Map<String^, Object^>());
|
|
}
|
|
frameState = safe_cast<IMap<String^, Object^>^>(_sessionState->Lookup(frameSessionKey));
|
|
}
|
|
else
|
|
{
|
|
// Frames that aren't registered have transient state
|
|
frameState = ref new Map<String^, Object^>();
|
|
}
|
|
frame->SetValue(FrameSessionStateProperty, frameState);
|
|
}
|
|
return frameState;
|
|
}
|
|
|
|
void SuspensionManager::RestoreFrameNavigationState(Frame^ frame)
|
|
{
|
|
auto frameState = SessionStateForFrame(frame);
|
|
if (frameState->HasKey("Navigation"))
|
|
{
|
|
frame->SetNavigationState(safe_cast<String^>(frameState->Lookup("Navigation")));
|
|
}
|
|
}
|
|
|
|
void SuspensionManager::SaveFrameNavigationState(Frame^ frame)
|
|
{
|
|
auto frameState = SessionStateForFrame(frame);
|
|
frameState->Insert("Navigation", frame->GetNavigationState());
|
|
}
|
|
|
|
/// <summary>
|
|
/// Save the current <see cref="SessionState"/>. Any <see cref="Frame"/> instances
|
|
/// registered with <see cref="RegisterFrame"/> will also preserve their current
|
|
/// navigation stack, which in turn gives their active <see cref="Page"/> an opportunity
|
|
/// to save its state.
|
|
/// </summary>
|
|
/// <returns>An asynchronous task that reflects when session state has been saved.</returns>
|
|
task<void> SuspensionManager::SaveAsync(void)
|
|
{
|
|
// Save the navigation state for all registered frames
|
|
for (auto&& weakFrame : _registeredFrames)
|
|
{
|
|
auto frame = weakFrame->ResolvedFrame;
|
|
if (frame != nullptr) SaveFrameNavigationState(frame);
|
|
}
|
|
|
|
// Serialize the session state synchronously to avoid asynchronous access to shared
|
|
// state
|
|
auto sessionData = ref new InMemoryRandomAccessStream();
|
|
auto sessionDataWriter = ref new DataWriter(sessionData->GetOutputStreamAt(0));
|
|
WriteObject(sessionDataWriter, _sessionState);
|
|
|
|
// Once session state has been captured synchronously, begin the asynchronous process
|
|
// of writing the result to disk
|
|
return task<unsigned int>(sessionDataWriter->StoreAsync()).then([=](unsigned int)
|
|
{
|
|
return sessionDataWriter->FlushAsync();
|
|
}).then([=](bool flushSucceeded)
|
|
{
|
|
(void)flushSucceeded; // Unused parameter
|
|
return ApplicationData::Current->LocalFolder->CreateFileAsync(sessionStateFilename,
|
|
CreationCollisionOption::ReplaceExisting);
|
|
}).then([=](StorageFile^ createdFile)
|
|
{
|
|
return createdFile->OpenAsync(FileAccessMode::ReadWrite);
|
|
}).then([=](IRandomAccessStream^ newStream)
|
|
{
|
|
return RandomAccessStream::CopyAndCloseAsync(
|
|
sessionData->GetInputStreamAt(0), newStream->GetOutputStreamAt(0));
|
|
}).then([=](UINT64 copiedBytes)
|
|
{
|
|
(void)copiedBytes; // Unused parameter
|
|
return;
|
|
});
|
|
}
|
|
|
|
/// <summary>
|
|
/// Restores previously saved <see cref="SessionState"/>. Any <see cref="Frame"/> instances
|
|
/// registered with <see cref="RegisterFrame"/> will also restore their prior navigation
|
|
/// state, which in turn gives their active <see cref="Page"/> an opportunity restore its
|
|
/// state.
|
|
/// </summary>
|
|
/// <param name="version">A version identifer compared to the session state to prevent
|
|
/// incompatible versions of session state from reaching app code. Saved state with a
|
|
/// different version will be ignored, resulting in an empty <see cref="SessionState"/>
|
|
/// dictionary.</param>
|
|
/// <returns>An asynchronous task that reflects when session state has been read. The
|
|
/// content of <see cref="SessionState"/> should not be relied upon until this task
|
|
/// completes.</returns>
|
|
task<void> SuspensionManager::RestoreAsync(void)
|
|
{
|
|
_sessionState->Clear();
|
|
|
|
task<StorageFile^> getFileTask(ApplicationData::Current->LocalFolder->GetFileAsync(sessionStateFilename));
|
|
return getFileTask.then([=](StorageFile^ stateFile)
|
|
{
|
|
task<BasicProperties^> getBasicPropertiesTask(stateFile->GetBasicPropertiesAsync());
|
|
return getBasicPropertiesTask.then([=](BasicProperties^ stateFileProperties)
|
|
{
|
|
auto size = unsigned int(stateFileProperties->Size);
|
|
if (size != stateFileProperties->Size) throw ref new FailureException("Session state larger than 4GB");
|
|
task<IRandomAccessStreamWithContentType^> openReadTask(stateFile->OpenReadAsync());
|
|
return openReadTask.then([=](IRandomAccessStreamWithContentType^ stateFileStream)
|
|
{
|
|
auto stateReader = ref new DataReader(stateFileStream);
|
|
return task<unsigned int>(stateReader->LoadAsync(size)).then([=](unsigned int bytesRead)
|
|
{
|
|
(void)bytesRead; // Unused parameter
|
|
// Deserialize the Session State
|
|
Object^ content = ReadObject(stateReader);
|
|
_sessionState = (Map<String^, Object^>^)content;
|
|
|
|
// Restore any registered frames to their saved state
|
|
for (auto&& weakFrame : _registeredFrames)
|
|
{
|
|
auto frame = weakFrame->ResolvedFrame;
|
|
if (frame != nullptr)
|
|
{
|
|
frame->ClearValue(FrameSessionStateProperty);
|
|
RestoreFrameNavigationState(frame);
|
|
}
|
|
}
|
|
}, task_continuation_context::use_current());
|
|
});
|
|
});
|
|
});
|
|
}
|
|
|
|
#pragma region Object serialization for a known set of types
|
|
|
|
namespace
|
|
{
|
|
// Codes used for identifying serialized types
|
|
enum StreamTypes {
|
|
NullPtrType = 0,
|
|
|
|
// Supported IPropertyValue types
|
|
UInt8Type, UInt16Type, UInt32Type, UInt64Type, Int16Type, Int32Type, Int64Type,
|
|
SingleType, DoubleType, BooleanType, Char16Type, GuidType, StringType,
|
|
|
|
// Additional supported types
|
|
StringToObjectMapType,
|
|
|
|
// Marker values used to ensure stream integrity
|
|
MapEndMarker
|
|
};
|
|
|
|
void WriteString(DataWriter^ writer, String^ string)
|
|
{
|
|
writer->WriteByte(StringType);
|
|
writer->WriteUInt32(writer->MeasureString(string));
|
|
writer->WriteString(string);
|
|
}
|
|
|
|
void WriteProperty(DataWriter^ writer, IPropertyValue^ propertyValue)
|
|
{
|
|
switch (propertyValue->Type)
|
|
{
|
|
case PropertyType::UInt8:
|
|
writer->WriteByte(UInt8Type);
|
|
writer->WriteByte(propertyValue->GetUInt8());
|
|
return;
|
|
case PropertyType::UInt16:
|
|
writer->WriteByte(UInt16Type);
|
|
writer->WriteUInt16(propertyValue->GetUInt16());
|
|
return;
|
|
case PropertyType::UInt32:
|
|
writer->WriteByte(UInt32Type);
|
|
writer->WriteUInt32(propertyValue->GetUInt32());
|
|
return;
|
|
case PropertyType::UInt64:
|
|
writer->WriteByte(UInt64Type);
|
|
writer->WriteUInt64(propertyValue->GetUInt64());
|
|
return;
|
|
case PropertyType::Int16:
|
|
writer->WriteByte(Int16Type);
|
|
writer->WriteUInt16(propertyValue->GetInt16());
|
|
return;
|
|
case PropertyType::Int32:
|
|
writer->WriteByte(Int32Type);
|
|
writer->WriteUInt32(propertyValue->GetInt32());
|
|
return;
|
|
case PropertyType::Int64:
|
|
writer->WriteByte(Int64Type);
|
|
writer->WriteUInt64(propertyValue->GetInt64());
|
|
return;
|
|
case PropertyType::Single:
|
|
writer->WriteByte(SingleType);
|
|
writer->WriteSingle(propertyValue->GetSingle());
|
|
return;
|
|
case PropertyType::Double:
|
|
writer->WriteByte(DoubleType);
|
|
writer->WriteDouble(propertyValue->GetDouble());
|
|
return;
|
|
case PropertyType::Boolean:
|
|
writer->WriteByte(BooleanType);
|
|
writer->WriteBoolean(propertyValue->GetBoolean());
|
|
return;
|
|
case PropertyType::Char16:
|
|
writer->WriteByte(Char16Type);
|
|
writer->WriteUInt16(propertyValue->GetChar16());
|
|
return;
|
|
case PropertyType::Guid:
|
|
writer->WriteByte(GuidType);
|
|
writer->WriteGuid(propertyValue->GetGuid());
|
|
return;
|
|
case PropertyType::String:
|
|
WriteString(writer, propertyValue->GetString());
|
|
return;
|
|
default:
|
|
throw ref new InvalidArgumentException("Unsupported property type");
|
|
}
|
|
}
|
|
|
|
void WriteStringToObjectMap(DataWriter^ writer, IMap<String^, Object^>^ map)
|
|
{
|
|
writer->WriteByte(StringToObjectMapType);
|
|
writer->WriteUInt32(map->Size);
|
|
for (auto&& pair : map)
|
|
{
|
|
WriteObject(writer, pair->Key);
|
|
WriteObject(writer, pair->Value);
|
|
}
|
|
writer->WriteByte(MapEndMarker);
|
|
}
|
|
|
|
void WriteObject(DataWriter^ writer, Object^ object)
|
|
{
|
|
if (object == nullptr)
|
|
{
|
|
writer->WriteByte(NullPtrType);
|
|
return;
|
|
}
|
|
|
|
auto propertyObject = dynamic_cast<IPropertyValue^>(object);
|
|
if (propertyObject != nullptr)
|
|
{
|
|
WriteProperty(writer, propertyObject);
|
|
return;
|
|
}
|
|
|
|
auto mapObject = dynamic_cast<IMap<String^, Object^>^>(object);
|
|
if (mapObject != nullptr)
|
|
{
|
|
WriteStringToObjectMap(writer, mapObject);
|
|
return;
|
|
}
|
|
|
|
throw ref new InvalidArgumentException("Unsupported data type");
|
|
}
|
|
|
|
String^ ReadString(DataReader^ reader)
|
|
{
|
|
int length = reader->ReadUInt32();
|
|
String^ string = reader->ReadString(length);
|
|
return string;
|
|
}
|
|
|
|
IMap<String^, Object^>^ ReadStringToObjectMap(DataReader^ reader)
|
|
{
|
|
auto map = ref new Map<String^, Object^>();
|
|
auto size = reader->ReadUInt32();
|
|
for (unsigned int index = 0; index < size; index++)
|
|
{
|
|
auto key = safe_cast<String^>(ReadObject(reader));
|
|
auto value = ReadObject(reader);
|
|
map->Insert(key, value);
|
|
}
|
|
if (reader->ReadByte() != MapEndMarker)
|
|
{
|
|
throw ref new InvalidArgumentException("Invalid stream");
|
|
}
|
|
return map;
|
|
}
|
|
|
|
Object^ ReadObject(DataReader^ reader)
|
|
{
|
|
auto type = reader->ReadByte();
|
|
switch (type)
|
|
{
|
|
case NullPtrType:
|
|
return nullptr;
|
|
case UInt8Type:
|
|
return reader->ReadByte();
|
|
case UInt16Type:
|
|
return reader->ReadUInt16();
|
|
case UInt32Type:
|
|
return reader->ReadUInt32();
|
|
case UInt64Type:
|
|
return reader->ReadUInt64();
|
|
case Int16Type:
|
|
return reader->ReadInt16();
|
|
case Int32Type:
|
|
return reader->ReadInt32();
|
|
case Int64Type:
|
|
return reader->ReadInt64();
|
|
case SingleType:
|
|
return reader->ReadSingle();
|
|
case DoubleType:
|
|
return reader->ReadDouble();
|
|
case BooleanType:
|
|
return reader->ReadBoolean();
|
|
case Char16Type:
|
|
return (char16_t)reader->ReadUInt16();
|
|
case GuidType:
|
|
return reader->ReadGuid();
|
|
case StringType:
|
|
return ReadString(reader);
|
|
case StringToObjectMapType:
|
|
return ReadStringToObjectMap(reader);
|
|
default:
|
|
throw ref new InvalidArgumentException("Unsupported property type");
|
|
}
|
|
}
|
|
}
|
|
|
|
#pragma endregion
|