--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PostgreSQL/Plugins/PostgreSQLIndex.cpp	Wed Jul 04 08:16:29 2018 +0200
@@ -0,0 +1,181 @@
+/**
+ * Orthanc - A Lightweight, RESTful DICOM Store
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2018 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 "PostgreSQLIndex.h"
+
+#include "../../Framework/Plugins/GlobalProperties.h"
+#include "../../Framework/PostgreSQL/PostgreSQLDatabase.h"
+#include "../../Framework/PostgreSQL/PostgreSQLTransaction.h"
+
+#include <EmbeddedResources.h>  // Auto-generated file
+
+#include <Core/Logging.h>
+#include <Core/OrthancException.h>
+
+
+namespace Orthanc
+{
+  // Some aliases for internal properties
+  static const GlobalProperty GlobalProperty_HasTrigramIndex = GlobalProperty_DatabaseInternal0;
+}
+
+
+namespace OrthancDatabases
+{
+  IDatabase* PostgreSQLIndex::OpenInternal()
+  {
+    uint32_t expectedVersion = 6;
+    if (context_)
+    {
+      expectedVersion = OrthancPluginGetExpectedDatabaseVersion(context_);
+    }
+    else
+    {
+      // This case only occurs during unit testing
+      expectedVersion = 6;
+    }
+
+    // Check the expected version of the database
+    if (expectedVersion != 6)
+    {
+      LOG(ERROR) << "This database plugin is incompatible with your version of Orthanc "
+                 << "expecting the DB schema version " << expectedVersion 
+                 << ", but this plugin is only compatible with version 6";
+      throw Orthanc::OrthancException(Orthanc::ErrorCode_Plugin);
+    }
+
+    std::auto_ptr<PostgreSQLDatabase> db(new PostgreSQLDatabase(parameters_));
+
+    db->Open();
+
+    if (clearAll_)
+    {
+      db->ClearAll();
+    }
+
+    {
+      PostgreSQLTransaction t(*db);
+
+      if (!db->DoesTableExist("Resources"))
+      {
+        std::string query;
+
+        Orthanc::EmbeddedResources::GetFileResource
+          (query, Orthanc::EmbeddedResources::POSTGRESQL_PREPARE_INDEX);
+        db->Execute(query);
+
+        SetGlobalIntegerProperty(*db, t, Orthanc::GlobalProperty_DatabaseSchemaVersion, expectedVersion);
+        SetGlobalIntegerProperty(*db, t, Orthanc::GlobalProperty_DatabasePatchLevel, 1);
+        SetGlobalIntegerProperty(*db, t, Orthanc::GlobalProperty_HasTrigramIndex, 0);
+      }
+          
+      t.Commit();
+    }
+
+    {
+      PostgreSQLTransaction t(*db);
+
+      if (!db->DoesTableExist("Resources"))
+      {
+        LOG(ERROR) << "Corrupted PostgreSQL database";
+        throw Orthanc::OrthancException(Orthanc::ErrorCode_InternalError);        
+      }
+
+      int version = 0;
+      if (!LookupGlobalIntegerProperty(version, *db, t, Orthanc::GlobalProperty_DatabaseSchemaVersion) ||
+          version != 6)
+      {
+        LOG(ERROR) << "PostgreSQL plugin is incompatible with database schema version: " << version;
+        throw Orthanc::OrthancException(Orthanc::ErrorCode_Database);        
+      }
+
+      int revision;
+      if (!LookupGlobalIntegerProperty(revision, *db, t, Orthanc::GlobalProperty_DatabasePatchLevel))
+      {
+        revision = 1;
+        SetGlobalIntegerProperty(*db, t, Orthanc::GlobalProperty_DatabasePatchLevel, revision);
+      }
+
+      int hasTrigram = 0;
+      if (!LookupGlobalIntegerProperty(hasTrigram, *db, t, Orthanc::GlobalProperty_HasTrigramIndex) ||
+          hasTrigram != 1)
+      {
+        // Apply fix for performance issue (speed up wildcard search by using GIN trigrams)
+        // https://www.postgresql.org/docs/current/static/pgtrgm.html
+        try
+        {
+          LOG(INFO) << "Trying to enable trigram matching on the PostgreSQL database to speed up wildcard searches";
+          db->Execute(
+            "CREATE EXTENSION pg_trgm; "
+            "CREATE INDEX DicomIdentifiersIndexValues_new ON DicomIdentifiers USING gin(value gin_trgm_ops); "
+            "DROP INDEX DicomIdentifiersIndexValues; "
+            "ALTER INDEX DicomIdentifiersIndexValues_new RENAME TO DicomIdentifiersIndexValues;");
+
+          SetGlobalIntegerProperty(*db, t, Orthanc::GlobalProperty_HasTrigramIndex, 1);
+        }
+        catch (Orthanc::OrthancException&)
+        {
+          LOG(WARNING) << "Performance warning: Your PostgreSQL server does not support trigram matching";
+          LOG(WARNING) << "-> Consider installing the \"pg_trgm\" extension on the PostgreSQL server, e.g. on Debian: sudo apt install postgresql-contrib";
+        }
+      }
+
+      if (revision != 1)
+      {
+        LOG(ERROR) << "PostgreSQL plugin is incompatible with database schema revision: " << revision;
+        throw Orthanc::OrthancException(Orthanc::ErrorCode_Database);        
+      }
+
+      t.Commit();
+    }
+
+    return db.release();
+  }
+
+
+  PostgreSQLIndex::PostgreSQLIndex(const PostgreSQLParameters& parameters) :
+    IndexBackend(new Factory(*this)),
+    context_(NULL),
+    parameters_(parameters),
+    clearAll_(false)
+  {
+  }
+
+  
+  int64_t PostgreSQLIndex::CreateResource(const char* publicId,
+                                          OrthancPluginResourceType type)
+  {
+    DatabaseManager::CachedStatement statement(
+      STATEMENT_FROM_HERE, GetManager(),
+      "INSERT INTO Resources VALUES(${}, ${type}, ${id}, NULL) RETURNING internalId");
+     
+    statement.SetParameterType("id", ValueType_Utf8String);
+    statement.SetParameterType("type", ValueType_Integer64);
+
+    Dictionary args;
+    args.SetUtf8Value("id", publicId);
+    args.SetIntegerValue("type", static_cast<int>(type));
+     
+    statement.Execute(args);
+
+    return ReadInteger64(statement, 0);
+  }
+}