Mercurial > hg > orthanc-databases
view PostgreSQL/Plugins/PostgreSQLStorageArea.cpp @ 134:cc3dc759c989
Added an advisory lock to avoid race conditions during database setup
author | Sebastien Jodogne <s.jodogne@gmail.com> |
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date | Wed, 08 May 2019 20:21:13 +0200 |
parents | 714c5d2bee76 |
children | 3266785d5627 |
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/** * Orthanc - A Lightweight, RESTful DICOM Store * 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 "PostgreSQLStorageArea.h" #include "../../Framework/PostgreSQL/PostgreSQLTransaction.h" #include <Plugins/Samples/Common/OrthancPluginCppWrapper.h> #include <Core/Logging.h> namespace OrthancDatabases { IDatabase* PostgreSQLStorageArea::OpenInternal() { std::auto_ptr<PostgreSQLDatabase> db(new PostgreSQLDatabase(parameters_)); db->Open(); if (parameters_.HasLock()) { db->AdvisoryLock(43 /* some arbitrary constant */); } /** * Try and acquire a transient advisory lock to protect the setup * of the database, because concurrent statements like "CREATE * TABLE" are not protected by transactions. * https://groups.google.com/d/msg/orthanc-users/yV3LSTh_TjI/h3PRApJFBAAJ **/ PostgreSQLDatabase::TransientAdvisoryLock lock(*db, 44 /* some arbitrary constant */); if (clearAll_) { db->ClearAll(); } { PostgreSQLTransaction t(*db); if (!db->DoesTableExist("StorageArea")) { db->Execute("CREATE TABLE IF NOT EXISTS StorageArea(" "uuid VARCHAR NOT NULL PRIMARY KEY," "content OID NOT NULL," "type INTEGER NOT NULL)"); // Automatically remove the large objects associated with the table db->Execute("CREATE OR REPLACE RULE StorageAreaDelete AS ON DELETE " "TO StorageArea DO SELECT lo_unlink(old.content);"); } t.Commit(); } return db.release(); } PostgreSQLStorageArea::PostgreSQLStorageArea(const PostgreSQLParameters& parameters) : StorageBackend(new Factory(*this)), parameters_(parameters), clearAll_(false) { } }