Improved Catalogue error handling and reporting

catalogue/AutoRollback.cpp

+/*
+ * The CERN Tape Archive (CTA) project
+ * Copyright (C) 2015  CERN
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "catalogue/AutoRollback.hpp"
+#include "catalogue/DbConn.hpp"
+#include "common/exception/Exception.hpp"
+
+namespace cta {
+namespace catalogue {
+
+//------------------------------------------------------------------------------
+// constructor
+//------------------------------------------------------------------------------
+AutoRollback::AutoRollback(DbConn *const dbConn): m_dbConn(dbConn) {
+}
+
+//------------------------------------------------------------------------------
+// destructor
+//------------------------------------------------------------------------------
+AutoRollback::~AutoRollback() {
+  try {
+    if(NULL != m_dbConn) {
+      m_dbConn->rollback();
+    }
+  } catch(...) {
+    // Prevent destructor from throwing
+  }
+}
+
+//------------------------------------------------------------------------------
+// cancel
+//------------------------------------------------------------------------------
+void AutoRollback::cancel() {
+  m_dbConn = NULL;
+}
+
+} // namespace catalogue
+} // namespace cta

catalogue/AutoRollback.hpp

+/*
+ * The CERN Tape Archive (CTA) project
+ * Copyright (C) 2015  CERN
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+namespace cta {
+namespace catalogue {
+
+/**
+ * Forward declaration.
+ */
+class DbConn;
+
+/**
+ * A class to automatically rollback a database connection when an instance of
+ * the class goes out of scope and has not been explictly cancelled.
+ */
+class AutoRollback {
+public:
+
+  /**
+   * Constructor.
+   *
+   * @param dbConn The database connection or NULL if the no rollback should
+   * take place.
+   */
+  AutoRollback(DbConn *const dbConn);
+
+  /**
+   * Prevent copying.
+   */
+  AutoRollback(const AutoRollback &) = delete;
+
+  /**
+   * Destructor.
+   */
+  ~AutoRollback();
+
+  /**
+   * Prevent assignment.
+   */
+  AutoRollback &operator=(const AutoRollback &) = delete;
+
+  /**
+   * Cancel the automatic rollback.
+   *
+   * This method is idempotent.
+   */
+  void cancel();
+
+private:
+
+  /**
+   * The database connection or NULL if no rollback should take place.
+   */
+  DbConn *m_dbConn;
+
+}; // class DbLogin
+
+} // namespace catalogue
+} // namespace cta

catalogue/CMakeLists.txt

@@ -22,6 +22,7 @@ include_directories (${ORACLE-INSTANTCLIENT_INCLUDE_DIRS})
 
 set (CATALOGUE_LIB_SRC_FILES
   ArchiveFileRow.cpp
+  AutoRollback.cpp
   Catalogue.cpp
   CatalogueFactory.cpp
   ColumnNameToIdx.cpp
@@ -46,7 +47,8 @@ set (CATALOGUE_LIB_SRC_FILES
   SqliteConn.cpp
   SqliteRset.cpp
   SqliteStmt.cpp
-  TapeForWriting.cpp)
+  TapeForWriting.cpp
+  UserError.cpp)
 
 add_library (ctacatalogue SHARED
   ${CATALOGUE_LIB_SRC_FILES})

catalogue/InMemoryCatalogueTest.cpp

@@ -19,6 +19,7 @@
 #include "catalogue/ArchiveFileRow.hpp"
 #include "catalogue/RdbmsCatalogue.hpp"
 #include "catalogue/CatalogueFactory.hpp"
+#include "catalogue/UserError.hpp"
 #include "common/exception/Exception.hpp"
 
 #include <gtest/gtest.h>
@@ -232,7 +233,7 @@ TEST_F(cta_catalogue_InMemoryCatalogueTest, createAdminUser_same_twice) {
   m_catalogue->createAdminUser(m_bootstrapAdminSI, m_adminSI.username, "comment 1");
 
   ASSERT_THROW(m_catalogue->createAdminUser(m_bootstrapAdminSI, m_adminSI.username,
-    "comment 2"), exception::Exception);
+    "comment 2"), catalogue::UserError);
 }
 
 TEST_F(cta_catalogue_InMemoryCatalogueTest, createAdminHost) {
@@ -341,7 +342,7 @@ TEST_F(cta_catalogue_InMemoryCatalogueTest, createAdminHost_same_twice) {
   m_catalogue->createAdminHost(m_bootstrapAdminSI, anotherAdminHost, "comment 1");
 
   ASSERT_THROW(m_catalogue->createAdminHost(m_bootstrapAdminSI,
-    anotherAdminHost, "comment 2"), exception::Exception);
+    anotherAdminHost, "comment 2"), catalogue::UserError);
 }
 
 TEST_F(cta_catalogue_InMemoryCatalogueTest, isAdmin_false) {
@@ -397,7 +398,7 @@ TEST_F(cta_catalogue_InMemoryCatalogueTest, createStorageClass_same_twice) {
   const std::string comment = "create storage class";
   m_catalogue->createStorageClass(m_cliSI, storageClassName, nbCopies, comment);
   ASSERT_THROW(m_catalogue->createStorageClass(m_cliSI,
-    storageClassName, nbCopies, comment), exception::Exception);
+    storageClassName, nbCopies, comment), catalogue::UserError);
 }
 
 TEST_F(cta_catalogue_InMemoryCatalogueTest, createTapePool) {
@@ -441,9 +442,8 @@ TEST_F(cta_catalogue_InMemoryCatalogueTest, createTapePool_same_twice) {
   const std::string comment = "create tape pool";
   m_catalogue->createTapePool(m_cliSI, tapePoolName, nbPartialTapes, is_encrypted,
     comment);
-  ASSERT_THROW(m_catalogue->createTapePool(m_cliSI,
-    tapePoolName, nbPartialTapes, is_encrypted, comment),
-    exception::Exception);
+  ASSERT_THROW(m_catalogue->createTapePool(m_cliSI, tapePoolName, nbPartialTapes, is_encrypted, comment),
+    catalogue::UserError);
 }
 
 TEST_F(cta_catalogue_InMemoryCatalogueTest, createArchiveRoute) {
@@ -595,9 +595,7 @@ TEST_F(cta_catalogue_InMemoryCatalogueTest, createLogicalLibrary_same_twice) {
   const std::string logicalLibraryName = "logical_library";
   const std::string comment = "create logical library";
   m_catalogue->createLogicalLibrary(m_cliSI, logicalLibraryName, comment);
-  ASSERT_THROW(m_catalogue->createLogicalLibrary(m_cliSI,
-    logicalLibraryName, comment),
-    exception::Exception);
+  ASSERT_THROW(m_catalogue->createLogicalLibrary(m_cliSI, logicalLibraryName, comment), catalogue::UserError);
 }
 
 TEST_F(cta_catalogue_InMemoryCatalogueTest, createTape) {
@@ -664,7 +662,7 @@ TEST_F(cta_catalogue_InMemoryCatalogueTest, createTape_same_twice) {
     encryptionKey, capacityInBytes, disabledValue, fullValue, comment);
   ASSERT_THROW(m_catalogue->createTape(m_cliSI, vid, logicalLibraryName,
     tapePoolName, encryptionKey, capacityInBytes, disabledValue, fullValue,
-    comment), exception::Exception);
+    comment), catalogue::UserError);
 }
 
 TEST_F(cta_catalogue_InMemoryCatalogueTest, getTapesForWriting) {
@@ -782,7 +780,7 @@ TEST_F(cta_catalogue_InMemoryCatalogueTest, createMountPolicy_same_twice) {
     retrievePriority,
     minRetrieveRequestAge,
     maxDrivesAllowed,
-    comment), exception::Exception);
+    comment), catalogue::UserError);
 }
 
 TEST_F(cta_catalogue_InMemoryCatalogueTest, createUser) {

catalogue/OracleCatalogue.cpp

@@ -19,6 +19,7 @@
 #include "catalogue/OcciConn.hpp"
 #include "catalogue/OcciEnvSingleton.hpp"
 #include "catalogue/OracleCatalogue.hpp"
+#include "common/exception/Exception.hpp"
 
 namespace cta {
 namespace catalogue {
@@ -46,5 +47,104 @@ uint64_t OracleCatalogue::getNextArchiveFileId() {
   throw exception::Exception(std::string(__FUNCTION__) + " not implemented");
 }
 
+//------------------------------------------------------------------------------
+// selectTapeForUpdate
+//------------------------------------------------------------------------------
+common::dataStructures::Tape OracleCatalogue::selectTapeForUpdate(const std::string &vid) {
+  try {
+    const char *const sql =
+      "SELECT "
+        "VID AS VID,"
+        "LOGICAL_LIBRARY_NAME AS LOGICAL_LIBRARY_NAME,"
+        "TAPE_POOL_NAME AS TAPE_POOL_NAME,"
+        "ENCRYPTION_KEY AS ENCRYPTION_KEY,"
+        "CAPACITY_IN_BYTES AS CAPACITY_IN_BYTES,"
+        "DATA_IN_BYTES AS DATA_IN_BYTES,"
+        "LAST_FSEQ AS LAST_FSEQ,"
+        "IS_DISABLED AS IS_DISABLED,"
+        "IS_FULL AS IS_FULL,"
+        "LBP_IS_ON AS LBP_IS_ON,"
+
+        "LABEL_DRIVE AS LABEL_DRIVE,"
+        "LABEL_TIME AS LABEL_TIME,"
+
+        "LAST_READ_DRIVE AS LAST_READ_DRIVE,"
+        "LAST_READ_TIME AS LAST_READ_TIME,"
+
+        "LAST_WRITE_DRIVE AS LAST_WRITE_DRIVE,"
+        "LAST_WRITE_TIME AS LAST_WRITE_TIME,"
+
+        "USER_COMMENT AS USER_COMMENT,"
+
+        "CREATION_LOG_USER_NAME AS CREATION_LOG_USER_NAME,"
+        "CREATION_LOG_HOST_NAME AS CREATION_LOG_HOST_NAME,"
+        "CREATION_LOG_TIME AS CREATION_LOG_TIME,"
+
+        "LAST_UPDATE_USER_NAME AS LAST_UPDATE_USER_NAME,"
+        "LAST_UPDATE_HOST_NAME AS LAST_UPDATE_HOST_NAME,"
+        "LAST_UPDATE_TIME AS LAST_UPDATE_TIME "
+      "FROM "
+        "TAPE "
+      "WHERE "
+        "VID = :VID "
+      "FOR UPDATE;";
+
+    std::unique_ptr<DbStmt> stmt(m_conn->createStmt(sql));
+    stmt->bindString(":VID", vid);
+    std::unique_ptr<DbRset> rset(stmt->executeQuery());
+    if (!rset->next()) {
+      throw exception::Exception(std::string("The tape with VID " + vid + " does not exist"));
+    }
+
+    common::dataStructures::Tape tape;
+
+    tape.vid = rset->columnText("VID");
+    tape.logicalLibraryName = rset->columnText("LOGICAL_LIBRARY_NAME");
+    tape.tapePoolName = rset->columnText("TAPE_POOL_NAME");
+    tape.encryptionKey = rset->columnText("ENCRYPTION_KEY");
+    tape.capacityInBytes = rset->columnUint64("CAPACITY_IN_BYTES");
+    tape.dataOnTapeInBytes = rset->columnUint64("DATA_IN_BYTES");
+    tape.lastFSeq = rset->columnUint64("LAST_FSEQ");
+    tape.disabled = rset->columnUint64("IS_DISABLED");
+    tape.full = rset->columnUint64("IS_FULL");
+    tape.lbp = rset->columnUint64("LBP_IS_ON");
+
+    tape.labelLog.drive = rset->columnText("LABEL_DRIVE");
+    tape.labelLog.time = rset->columnUint64("LABEL_TIME");
+
+    tape.lastReadLog.drive = rset->columnText("LAST_READ_DRIVE");
+    tape.lastReadLog.time = rset->columnUint64("LAST_READ_TIME");
+
+    tape.lastWriteLog.drive = rset->columnText("LAST_WRITE_DRIVE");
+    tape.lastWriteLog.time = rset->columnUint64("LAST_WRITE_TIME");
+
+    tape.comment = rset->columnText("USER_COMMENT");
+
+    common::dataStructures::UserIdentity creatorUI;
+    creatorUI.name = rset->columnText("CREATION_LOG_USER_NAME");
+
+    common::dataStructures::EntryLog creationLog;
+    creationLog.username = rset->columnText("CREATION_LOG_USER_NAME");
+    creationLog.host = rset->columnText("CREATION_LOG_HOST_NAME");
+    creationLog.time = rset->columnUint64("CREATION_LOG_TIME");
+
+    tape.creationLog = creationLog;
+
+    common::dataStructures::UserIdentity updaterUI;
+    updaterUI.name = rset->columnText("LAST_UPDATE_USER_NAME");
+
+    common::dataStructures::EntryLog updateLog;
+    updateLog.username = rset->columnText("LAST_UPDATE_USER_NAME");
+    updateLog.host = rset->columnText("LAST_UPDATE_HOST_NAME");
+    updateLog.time = rset->columnUint64("LAST_UPDATE_TIME");
+
+    tape.lastModificationLog = updateLog;
+
+    return tape;
+  } catch (exception::Exception &ex) {
+    throw exception::Exception(std::string(__FUNCTION__) + " failed: " + ex.getMessage().str());
+  }
+}
+
 } // namespace catalogue
 } // namespace cta

catalogue/OracleCatalogue.hpp

@@ -68,6 +68,17 @@ public:
    */
   virtual uint64_t getNextArchiveFileId();
 
+  /**
+   * Selects the specified tape within th eTape table for update.
+   *
+   * This method must be implemented by the sub-classes of RdbmsCatalogue
+   * because some database technologies directly support SELECT FOR UPDATE
+   * whilst others do not.
+   *
+   * @param vid The volume identifier of the tape.
+   */
+  virtual common::dataStructures::Tape selectTapeForUpdate(const std::string &vid);
+
 }; // class OracleCatalogue
 
 } // namespace catalogue

catalogue/RdbmsCatalogue.hpp

@@ -243,24 +243,68 @@ public:
 protected:
 
   /**
-   * An RdbmsCatalogue specific method that inserts the specified row into the
-   * ArchiveFile table.
+   * Returns true if the specified admin user exists.
    *
-   * @param row The row to be inserted.
+   * @param adminUsername The name of the admin user.
+   * @return True if the admin user exists.
    */
-  void insertArchiveFile(const ArchiveFileRow &row);
+  bool adminUserExists(const std::string adminUsername) const;
+
+  /**
+   * Returns true if the specified admin host exists.
+   *
+   * @param adminHost The name of the admin host.
+   * @return True if the admin host exists.
+   */
+  bool adminHostExists(const std::string adminHost) const;
+
+  /**
+   * Returns true if the specified storage class exists.
+   *
+   * @param storageClassName The name of the storage class.
+   * @return True if the storage class exists.
+   */
+  bool storageClassExists(const std::string &storageClassName) const;
+
+  /**
+   * Returns true if the specified tape pool exists.
+   *
+   * @param tapePoolName The name of the tape pool.
+   * @return True if the tape pool exists.
+   */
+  bool tapePoolExists(const std::string &tapePoolName) const;
+
+  /**
+   * Returns true if the specified tape exists.
+   *
+   * @param vid The volume identifier of the tape.
+   * @return True if the tape exists.
+   */
+  bool tapeExists(const std::string &vid) const;
+
+  /**
+   * Returns true if the specified logical library exists.
+   *
+   * @param logicalLibraryName The name of the logical library.
+   * @return True if the logical library exists.
+   */
+  bool logicalLibraryExists(const std::string &logicalLibraryName) const;
+
+  /**
+   * Returns true if the specified mount policy exists.
+   *
+   * @param mountPolicyName The name of the mount policy
+   * @return True if the mount policy exists.
+   */
+  bool mountPolicyExists(const std::string &mountPolicyName) const;
 
   /**
-   * Returns the unique identifier of the specified archive file.  Note that
-   * this method is required by RdbmsCatalogue because SQLite does not support
-   * the SQL syntax: "INSERT INTO ... VALUES ... RETURNING ... INTO ...".
+   * An RdbmsCatalogue specific method that inserts the specified row into the
+   * ArchiveFile table.
    *
-   * @param diskInstance The name of teh disk storage instance within which the
-   * specified disk file identifier is unique.
-   * @param diskFileId The disk identifier of the file.
-   * @return The unique identifier of the specified archive file.
+   * @param row The row to be inserted.
    */
-  uint64_t getArchiveFileId(const std::string &diskInstance, const std::string &diskFileId) const;
+  void insertArchiveFile(const ArchiveFileRow &row);
 
   /**
    * Mutex to be used to a take a global lock on the in-memory database.
@@ -323,20 +367,13 @@ protected:
   void setTapeLastFSeq(const std::string &vid, const uint64_t lastFSeq);
 
   /**
-   * Returns the last FSeq of the speficied tape.
+   * Returns the last FSeq of the specified tape.
    *
    * @param vid The volume identifier of the tape.
    * @return The last FSeq.
    */
   uint64_t getTapeLastFSeq(const std::string &vid) const;
 
-  /**
-   * Selects the specified tape within th eTape table for update.
-   *
-   * @param vid The volume identifier of the tape.
-   */
-  common::dataStructures::Tape selectTapeForUpdate(const std::string &vid);
-
   /**
    * Updates the lastFSeq column of the specified tape within the Tape table.
    *
@@ -382,6 +419,17 @@ protected:
    */
   virtual uint64_t getNextArchiveFileId() = 0;
 
+  /**
+   * Selects the specified tape within th eTape table for update.
+   *
+   * This method must be implemented by the sub-classes of RdbmsCatalogue
+   * because some database technologies directly support SELECT FOR UPDATE
+   * whilst others do not.
+   *
+   * @param vid The volume identifier of the tape.
+   */
+  virtual common::dataStructures::Tape selectTapeForUpdate(const std::string &vid) = 0;
+
 }; // class RdbmsCatalogue
 
 } // namespace catalogue

catalogue/SqliteCatalogue.cpp

@@ -19,6 +19,7 @@
 #include "catalogue/SqliteCatalogue.hpp"
 #include "catalogue/RdbmsCatalogueSchema.hpp"
 #include "catalogue/SqliteConn.hpp"
+#include "common/exception/Exception.hpp"
 
 namespace cta {
 namespace catalogue {
@@ -75,5 +76,107 @@ uint64_t SqliteCatalogue::getNextArchiveFileId() {
   }
 }
 
+//------------------------------------------------------------------------------
+// selectTapeForUpdate
+//------------------------------------------------------------------------------
+common::dataStructures::Tape SqliteCatalogue::selectTapeForUpdate(const std::string &vid) {
+  try {
+    // SQLite does not support SELECT FOR UPDATE
+    // Emulate SELECT FOR UPDATE by taking an exclusive lock on the database
+    m_conn->executeNonQuery("BEGIN EXCLUSIVE;");
+
+    const char *const sql =
+      "SELECT "
+        "VID AS VID,"
+        "LOGICAL_LIBRARY_NAME AS LOGICAL_LIBRARY_NAME,"
+        "TAPE_POOL_NAME AS TAPE_POOL_NAME,"
+        "ENCRYPTION_KEY AS ENCRYPTION_KEY,"
+        "CAPACITY_IN_BYTES AS CAPACITY_IN_BYTES,"
+        "DATA_IN_BYTES AS DATA_IN_BYTES,"
+        "LAST_FSEQ AS LAST_FSEQ,"
+        "IS_DISABLED AS IS_DISABLED,"
+        "IS_FULL AS IS_FULL,"
+        "LBP_IS_ON AS LBP_IS_ON,"
+
+        "LABEL_DRIVE AS LABEL_DRIVE,"
+        "LABEL_TIME AS LABEL_TIME,"
+
+        "LAST_READ_DRIVE AS LAST_READ_DRIVE,"
+        "LAST_READ_TIME AS LAST_READ_TIME,"
+
+        "LAST_WRITE_DRIVE AS LAST_WRITE_DRIVE,"
+        "LAST_WRITE_TIME AS LAST_WRITE_TIME,"
+
+        "USER_COMMENT AS USER_COMMENT,"
+
+        "CREATION_LOG_USER_NAME AS CREATION_LOG_USER_NAME,"
+        "CREATION_LOG_HOST_NAME AS CREATION_LOG_HOST_NAME,"
+        "CREATION_LOG_TIME AS CREATION_LOG_TIME,"
+
+        "LAST_UPDATE_USER_NAME AS LAST_UPDATE_USER_NAME,"
+        "LAST_UPDATE_HOST_NAME AS LAST_UPDATE_HOST_NAME,"
+        "LAST_UPDATE_TIME AS LAST_UPDATE_TIME "
+      "FROM "
+        "TAPE "
+      "WHERE "
+        "VID = :VID;";
+
+    std::unique_ptr<DbStmt> stmt(m_conn->createStmt(sql));
+    stmt->bindString(":VID", vid);
+    std::unique_ptr<DbRset> rset(stmt->executeQuery());
+    if (!rset->next()) {
+      throw exception::Exception(std::string("The tape with VID " + vid + " does not exist"));
+    }
+
+    common::dataStructures::Tape tape;
+
+    tape.vid = rset->columnText("VID");
+    tape.logicalLibraryName = rset->columnText("LOGICAL_LIBRARY_NAME");
+    tape.tapePoolName = rset->columnText("TAPE_POOL_NAME");
+    tape.encryptionKey = rset->columnText("ENCRYPTION_KEY");
+    tape.capacityInBytes = rset->columnUint64("CAPACITY_IN_BYTES");
+    tape.dataOnTapeInBytes = rset->columnUint64("DATA_IN_BYTES");
+    tape.lastFSeq = rset->columnUint64("LAST_FSEQ");
+    tape.disabled = rset->columnUint64("IS_DISABLED");
+    tape.full = rset->columnUint64("IS_FULL");
+    tape.lbp = rset->columnUint64("LBP_IS_ON");
+
+    tape.labelLog.drive = rset->columnText("LABEL_DRIVE");
+    tape.labelLog.time = rset->columnUint64("LABEL_TIME");
+
+    tape.lastReadLog.drive = rset->columnText("LAST_READ_DRIVE");
+    tape.lastReadLog.time = rset->columnUint64("LAST_READ_TIME");
+
+    tape.lastWriteLog.drive = rset->columnText("LAST_WRITE_DRIVE");
+    tape.lastWriteLog.time = rset->columnUint64("LAST_WRITE_TIME");
+
+    tape.comment = rset->columnText("USER_COMMENT");
+
+    common::dataStructures::UserIdentity creatorUI;
+    creatorUI.name = rset->columnText("CREATION_LOG_USER_NAME");
+
+    common::dataStructures::EntryLog creationLog;
+    creationLog.username = rset->columnText("CREATION_LOG_USER_NAME");
+    creationLog.host = rset->columnText("CREATION_LOG_HOST_NAME");
+    creationLog.time = rset->columnUint64("CREATION_LOG_TIME");
+
+    tape.creationLog = creationLog;
+
+    common::dataStructures::UserIdentity updaterUI;
+    updaterUI.name = rset->columnText("LAST_UPDATE_USER_NAME");
+
+    common::dataStructures::EntryLog updateLog;
+    updateLog.username = rset->columnText("LAST_UPDATE_USER_NAME");
+    updateLog.host = rset->columnText("LAST_UPDATE_HOST_NAME");
+    updateLog.time = rset->columnUint64("LAST_UPDATE_TIME");
+
+    tape.lastModificationLog = updateLog;
+
+    return tape;
+  } catch (exception::Exception &ex) {
+    throw exception::Exception(std::string(__FUNCTION__) + " failed: " + ex.getMessage().str());
+  }
+}
+
 } // namespace catalogue
 } // namespace cta

catalogue/SqliteCatalogue.hpp

@@ -75,6 +75,17 @@ protected:
    */
   virtual uint64_t getNextArchiveFileId();
 
+  /**
+   * Selects the specified tape within th eTape table for update.
+   *
+   * This method must be implemented by the sub-classes of RdbmsCatalogue
+   * because some database technologies directly support SELECT FOR UPDATE
+   * whilst others do not.
+   *
+   * @param vid The volume identifier of the tape.
+   */
+  virtual common::dataStructures::Tape selectTapeForUpdate(const std::string &vid);
+
 }; // class SqliteCatalogue
 
 } // namespace catalogue

catalogue/SqliteConn.cpp

@@ -100,7 +100,11 @@ void SqliteConn::commit() {
 // commit
 //------------------------------------------------------------------------------
 void SqliteConn::rollback() {
-  throw exception::Exception(std::string(__FUNCTION__) + " not implemented");
+  try {
+    executeNonQuery("ROLLBACK;");
+  } catch(exception::Exception &ex) {