--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/OrthancServer/Plugins/Samples/DelayedDeletion/PendingDeletionsDatabase.cpp	Mon Jun 20 16:53:21 2022 +0200
@@ -0,0 +1,112 @@
+#include "PendingDeletionsDatabase.h"
+
+#include "../../../../OrthancFramework/Sources/SQLite/Statement.h"
+#include "../../../../OrthancFramework/Sources/SQLite/Transaction.h"
+
+void PendingDeletionsDatabase::Setup()
+{
+  // Performance tuning of SQLite with PRAGMAs
+  // http://www.sqlite.org/pragma.html
+  db_.Execute("PRAGMA SYNCHRONOUS=NORMAL;");
+  db_.Execute("PRAGMA JOURNAL_MODE=WAL;");
+  db_.Execute("PRAGMA LOCKING_MODE=EXCLUSIVE;");
+  db_.Execute("PRAGMA WAL_AUTOCHECKPOINT=1000;");
+
+  {
+    Orthanc::SQLite::Transaction t(db_);
+    t.Begin();
+
+    if (!db_.DoesTableExist("Pending"))
+    {
+      db_.Execute("CREATE TABLE Pending(uuid TEXT, type INTEGER)");
+    }
+    
+    t.Commit();
+  }
+}
+  
+
+PendingDeletionsDatabase::PendingDeletionsDatabase(const std::string& path)
+{
+  db_.Open(path);
+  Setup();
+}
+  
+
+void PendingDeletionsDatabase::Enqueue(const std::string& uuid,
+                                       Orthanc::FileContentType type)
+{
+  boost::mutex::scoped_lock lock(mutex_);
+
+  Orthanc::SQLite::Transaction t(db_);
+  t.Begin();
+
+  {
+    Orthanc::SQLite::Statement s(db_, SQLITE_FROM_HERE, "INSERT INTO Pending VALUES(?, ?)");
+    s.BindString(0, uuid);
+    s.BindInt(1, type);
+    s.Run();
+  }
+
+  t.Commit();
+}
+  
+
+bool PendingDeletionsDatabase::Dequeue(std::string& uuid,
+                                       Orthanc::FileContentType& type)
+{
+  bool ok = false;
+    
+  boost::mutex::scoped_lock lock(mutex_);
+
+  Orthanc::SQLite::Transaction t(db_);
+  t.Begin();
+
+  {
+    Orthanc::SQLite::Statement s(db_, SQLITE_FROM_HERE, "SELECT uuid, type FROM Pending LIMIT 1");
+
+    if (s.Step())
+    {
+      uuid = s.ColumnString(0);
+      type = static_cast<Orthanc::FileContentType>(s.ColumnInt(1));
+
+      Orthanc::SQLite::Statement s(db_, SQLITE_FROM_HERE, "DELETE FROM Pending WHERE uuid=?");
+      s.BindString(0, uuid);
+      s.Run();
+      
+      ok = true;
+    }
+  }
+
+  t.Commit();
+
+  return ok;
+}
+
+
+unsigned int PendingDeletionsDatabase::GetSize()
+{
+  boost::mutex::scoped_lock lock(mutex_);
+
+  unsigned int value = 0;
+  
+  Orthanc::SQLite::Transaction t(db_);
+  t.Begin();
+
+  {
+    Orthanc::SQLite::Statement s(db_, SQLITE_FROM_HERE, "SELECT COUNT(*) FROM Pending");
+
+    if (s.Step())
+    {
+      int tmp = s.ColumnInt(0);
+      if (tmp > 0)
+      {
+        value = static_cast<unsigned int>(tmp);
+      }
+    }
+  }
+
+  t.Commit();
+
+  return value;
+}