--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Framework/Oracle/ThreadedOracle.cpp	Wed May 22 14:46:26 2019 +0200
@@ -0,0 +1,507 @@
+/**
+ * Stone of Orthanc
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2019 Osimis S.A., Belgium
+ *
+ * This program is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU Affero General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Affero General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ **/
+
+
+#include "ThreadedOracle.h"
+
+#include "GetOrthancImageCommand.h"
+#include "GetOrthancWebViewerJpegCommand.h"
+#include "OrthancRestApiCommand.h"
+#include "SleepOracleCommand.h"
+#include "OracleCommandExceptionMessage.h"
+
+#include <Core/Compression/GzipCompressor.h>
+#include <Core/HttpClient.h>
+#include <Core/OrthancException.h>
+#include <Core/Toolbox.h>
+
+
+namespace OrthancStone
+{
+  class ThreadedOracle::Item : public Orthanc::IDynamicObject
+  {
+  private:
+    const IObserver&                receiver_;
+    std::auto_ptr<IOracleCommand>   command_;
+
+  public:
+    Item(const IObserver& receiver,
+         IOracleCommand* command) :
+      receiver_(receiver),
+      command_(command)
+    {
+      if (command == NULL)
+      {
+        throw Orthanc::OrthancException(Orthanc::ErrorCode_NullPointer);
+      }
+    }
+
+    const IObserver& GetReceiver() const
+    {
+      return receiver_;
+    }
+
+    IOracleCommand& GetCommand()
+    {
+      assert(command_.get() != NULL);
+      return *command_;
+    }
+  };
+
+
+  class ThreadedOracle::SleepingCommands : public boost::noncopyable
+  {
+  private:
+    class Item
+    {
+    private:
+      const IObserver&                   receiver_;
+      std::auto_ptr<SleepOracleCommand>  command_;
+      boost::posix_time::ptime           expiration_;
+
+    public:
+      Item(const IObserver& receiver,
+           SleepOracleCommand* command) :
+        receiver_(receiver),
+        command_(command)
+      {
+        if (command == NULL)
+        {
+          throw Orthanc::OrthancException(Orthanc::ErrorCode_NullPointer);
+        }
+
+        expiration_ = (boost::posix_time::second_clock::local_time() + 
+                       boost::posix_time::milliseconds(command_->GetDelay()));
+      }
+
+      const boost::posix_time::ptime& GetExpirationTime() const
+      {
+        return expiration_;
+      }
+
+      void Awake(IMessageEmitter& emitter)
+      {
+        assert(command_.get() != NULL);
+
+        SleepOracleCommand::TimeoutMessage message(*command_);
+        emitter.EmitMessage(receiver_, message);
+      }
+    };
+
+    typedef std::list<Item*>  Content;
+
+    boost::mutex  mutex_;
+    Content       content_;
+
+  public:
+    ~SleepingCommands()
+    {
+      for (Content::iterator it = content_.begin(); it != content_.end(); ++it)
+      {
+        if (*it != NULL)
+        {
+          delete *it;
+        }
+      }
+    }
+
+    void Add(const IObserver& receiver,
+             SleepOracleCommand* command)   // Takes ownership
+    {
+      boost::mutex::scoped_lock lock(mutex_);
+
+      content_.push_back(new Item(receiver, command));
+    }
+
+    void AwakeExpired(IMessageEmitter& emitter)
+    {
+      boost::mutex::scoped_lock lock(mutex_);
+
+      const boost::posix_time::ptime now = boost::posix_time::second_clock::local_time();
+
+      Content  stillSleeping;
+        
+      for (Content::iterator it = content_.begin(); it != content_.end(); ++it)
+      {
+        if (*it != NULL &&
+            (*it)->GetExpirationTime() <= now)
+        {
+          (*it)->Awake(emitter);
+          delete *it;
+          *it = NULL;
+        }
+        else
+        {
+          stillSleeping.push_back(*it);
+        }
+      }
+
+      // Compact the still-sleeping commands
+      content_ = stillSleeping;
+    }
+  };
+
+
+  static void CopyHttpHeaders(Orthanc::HttpClient& client,
+                              const Orthanc::HttpClient::HttpHeaders& headers)
+  {
+    for (Orthanc::HttpClient::HttpHeaders::const_iterator
+           it = headers.begin(); it != headers.end(); it++ )
+    {
+      client.AddHeader(it->first, it->second);
+    }
+  }
+
+
+  static void DecodeAnswer(std::string& answer,
+                           const Orthanc::HttpClient::HttpHeaders& headers)
+  {
+    Orthanc::HttpCompression contentEncoding = Orthanc::HttpCompression_None;
+
+    for (Orthanc::HttpClient::HttpHeaders::const_iterator it = headers.begin(); 
+         it != headers.end(); ++it)
+    {
+      std::string s;
+      Orthanc::Toolbox::ToLowerCase(s, it->first);
+
+      if (s == "content-encoding")
+      {
+        if (it->second == "gzip")
+        {
+          contentEncoding = Orthanc::HttpCompression_Gzip;
+        }
+        else 
+        {
+          throw Orthanc::OrthancException(Orthanc::ErrorCode_NetworkProtocol,
+                                          "Unsupported HTTP Content-Encoding: " + it->second);
+        }
+
+        break;
+      }
+    }
+
+    if (contentEncoding == Orthanc::HttpCompression_Gzip)
+    {
+      std::string compressed;
+      answer.swap(compressed);
+          
+      Orthanc::GzipCompressor compressor;
+      compressor.Uncompress(answer, compressed.c_str(), compressed.size());
+    }
+  }
+
+
+  static void Execute(IMessageEmitter& emitter,
+                      const Orthanc::WebServiceParameters& orthanc,
+                      const IObserver& receiver,
+                      const OrthancRestApiCommand& command)
+  {
+    Orthanc::HttpClient client(orthanc, command.GetUri());
+    client.SetMethod(command.GetMethod());
+    client.SetTimeout(command.GetTimeout());
+
+    CopyHttpHeaders(client, command.GetHttpHeaders());
+
+    if (command.GetMethod() == Orthanc::HttpMethod_Post ||
+        command.GetMethod() == Orthanc::HttpMethod_Put)
+    {
+      client.SetBody(command.GetBody());
+    }
+
+    std::string answer;
+    Orthanc::HttpClient::HttpHeaders answerHeaders;
+    client.ApplyAndThrowException(answer, answerHeaders);
+
+    DecodeAnswer(answer, answerHeaders);
+
+    OrthancRestApiCommand::SuccessMessage message(command, answerHeaders, answer);
+    emitter.EmitMessage(receiver, message);
+  }
+
+
+  static void Execute(IMessageEmitter& emitter,
+                      const Orthanc::WebServiceParameters& orthanc,
+                      const IObserver& receiver,
+                      const GetOrthancImageCommand& command)
+  {
+    Orthanc::HttpClient client(orthanc, command.GetUri());
+    client.SetTimeout(command.GetTimeout());
+
+    CopyHttpHeaders(client, command.GetHttpHeaders());
+
+    std::string answer;
+    Orthanc::HttpClient::HttpHeaders answerHeaders;
+    client.ApplyAndThrowException(answer, answerHeaders);
+
+    DecodeAnswer(answer, answerHeaders);
+
+    command.ProcessHttpAnswer(emitter, receiver, answer, answerHeaders);
+  }
+
+
+  static void Execute(IMessageEmitter& emitter,
+                      const Orthanc::WebServiceParameters& orthanc,
+                      const IObserver& receiver,
+                      const GetOrthancWebViewerJpegCommand& command)
+  {
+    Orthanc::HttpClient client(orthanc, command.GetUri());
+    client.SetTimeout(command.GetTimeout());
+
+    CopyHttpHeaders(client, command.GetHttpHeaders());
+
+    std::string answer;
+    Orthanc::HttpClient::HttpHeaders answerHeaders;
+    client.ApplyAndThrowException(answer, answerHeaders);
+
+    DecodeAnswer(answer, answerHeaders);
+
+    command.ProcessHttpAnswer(emitter, receiver, answer);
+  }
+
+
+  void ThreadedOracle::Step()
+  {
+    std::auto_ptr<Orthanc::IDynamicObject>  object(queue_.Dequeue(100));
+
+    if (object.get() != NULL)
+    {
+      Item& item = dynamic_cast<Item&>(*object);
+
+      try
+      {
+        switch (item.GetCommand().GetType())
+        {
+          case IOracleCommand::Type_Sleep:
+          {
+            SleepOracleCommand& command = dynamic_cast<SleepOracleCommand&>(item.GetCommand());
+
+            std::auto_ptr<SleepOracleCommand> copy(new SleepOracleCommand(command.GetDelay()));
+
+            if (command.HasPayload())
+            {
+              copy->SetPayload(command.ReleasePayload());
+            }
+
+            sleepingCommands_->Add(item.GetReceiver(), copy.release());
+
+            break;
+          }
+
+          case IOracleCommand::Type_OrthancRestApi:
+            Execute(emitter_, orthanc_, item.GetReceiver(), 
+                    dynamic_cast<const OrthancRestApiCommand&>(item.GetCommand()));
+            break;
+
+          case IOracleCommand::Type_GetOrthancImage:
+            Execute(emitter_, orthanc_, item.GetReceiver(), 
+                    dynamic_cast<const GetOrthancImageCommand&>(item.GetCommand()));
+            break;
+
+          case IOracleCommand::Type_GetOrthancWebViewerJpeg:
+            Execute(emitter_, orthanc_, item.GetReceiver(), 
+                    dynamic_cast<const GetOrthancWebViewerJpegCommand&>(item.GetCommand()));
+            break;
+
+          default:
+            throw Orthanc::OrthancException(Orthanc::ErrorCode_NotImplemented);
+        }
+      }
+      catch (Orthanc::OrthancException& e)
+      {
+        LOG(ERROR) << "Exception within the oracle: " << e.What();
+        emitter_.EmitMessage(item.GetReceiver(), OracleCommandExceptionMessage(item.GetCommand(), e));
+      }
+      catch (...)
+      {
+        LOG(ERROR) << "Threaded exception within the oracle";
+        emitter_.EmitMessage(item.GetReceiver(), OracleCommandExceptionMessage
+                             (item.GetCommand(), Orthanc::ErrorCode_InternalError));
+      }
+    }
+  }
+
+
+  void ThreadedOracle::Worker(ThreadedOracle* that)
+  {
+    assert(that != NULL);
+      
+    for (;;)
+    {
+      {
+        boost::mutex::scoped_lock lock(that->mutex_);
+        if (that->state_ != State_Running)
+        {
+          return;
+        }
+      }
+
+      that->Step();
+    }
+  }
+
+
+  void ThreadedOracle::SleepingWorker(ThreadedOracle* that)
+  {
+    assert(that != NULL);
+      
+    for (;;)
+    {
+      {
+        boost::mutex::scoped_lock lock(that->mutex_);
+        if (that->state_ != State_Running)
+        {
+          return;
+        }
+      }
+
+      that->sleepingCommands_->AwakeExpired(that->emitter_);
+
+      boost::this_thread::sleep(boost::posix_time::milliseconds(that->sleepingTimeResolution_));
+    }
+  }
+
+
+  void ThreadedOracle::StopInternal()
+  {
+    {
+      boost::mutex::scoped_lock lock(mutex_);
+
+      if (state_ == State_Setup ||
+          state_ == State_Stopped)
+      {
+        return;
+      }
+      else
+      {
+        state_ = State_Stopped;
+      }
+    }
+
+    if (sleepingWorker_.joinable())
+    {
+      sleepingWorker_.join();
+    }
+
+    for (size_t i = 0; i < workers_.size(); i++)
+    {
+      if (workers_[i] != NULL)
+      {
+        if (workers_[i]->joinable())
+        {
+          workers_[i]->join();
+        }
+
+        delete workers_[i];
+      }
+    } 
+  }
+
+
+  ThreadedOracle::ThreadedOracle(IMessageEmitter& emitter) :
+    emitter_(emitter),
+    state_(State_Setup),
+    workers_(4),
+    sleepingCommands_(new SleepingCommands),
+    sleepingTimeResolution_(50)  // By default, time resolution of 50ms
+  {
+  }
+
+
+  void ThreadedOracle::SetOrthancParameters(const Orthanc::WebServiceParameters& orthanc)
+  {
+    boost::mutex::scoped_lock lock(mutex_);
+
+    if (state_ != State_Setup)
+    {
+      throw Orthanc::OrthancException(Orthanc::ErrorCode_BadSequenceOfCalls);
+    }
+    else
+    {
+      orthanc_ = orthanc;
+    }
+  }
+
+
+  void ThreadedOracle::SetWorkersCount(unsigned int count)
+  {
+    boost::mutex::scoped_lock lock(mutex_);
+
+    if (count <= 0)
+    {
+      throw Orthanc::OrthancException(Orthanc::ErrorCode_ParameterOutOfRange);
+    }
+    else if (state_ != State_Setup)
+    {
+      throw Orthanc::OrthancException(Orthanc::ErrorCode_BadSequenceOfCalls);
+    }
+    else
+    {
+      workers_.resize(count);
+    }
+  }
+
+
+  void ThreadedOracle::SetSleepingTimeResolution(unsigned int milliseconds)
+  {
+    boost::mutex::scoped_lock lock(mutex_);
+
+    if (milliseconds <= 0)
+    {
+      throw Orthanc::OrthancException(Orthanc::ErrorCode_ParameterOutOfRange);
+    }
+    else if (state_ != State_Setup)
+    {
+      throw Orthanc::OrthancException(Orthanc::ErrorCode_BadSequenceOfCalls);
+    }
+    else
+    {
+      sleepingTimeResolution_ = milliseconds;
+    }
+  }
+
+
+  void ThreadedOracle::Start()
+  {
+    boost::mutex::scoped_lock lock(mutex_);
+
+    if (state_ != State_Setup)
+    {
+      throw Orthanc::OrthancException(Orthanc::ErrorCode_BadSequenceOfCalls);
+    }
+    else
+    {
+      state_ = State_Running;
+
+      for (unsigned int i = 0; i < workers_.size(); i++)
+      {
+        workers_[i] = new boost::thread(Worker, this);
+      }
+
+      sleepingWorker_ = boost::thread(SleepingWorker, this);
+    }      
+  }
+
+
+  void ThreadedOracle::Schedule(const IObserver& receiver,
+                                IOracleCommand* command)
+  {
+    queue_.Enqueue(new Item(receiver, command));
+  }
+}