Examples with ManagedConnection org.datanucleus.store.connection.ManagedConnection used on opensource projects

Example 6 with ManagedConnection

use of org.datanucleus.store.connection.ManagedConnection in project datanucleus-rdbms by datanucleus.

the class InsertRequest method execute.

/**
 * Method performing the insertion of the record from the datastore.
 * Takes the constructed insert query and populates with the specific record information.
 * @param op The ObjectProvider for the record to be inserted
 */
public void execute(ObjectProvider op) {
    ExecutionContext ec = op.getExecutionContext();
    if (NucleusLogger.PERSISTENCE.isDebugEnabled()) {
        // Debug information about what we are inserting
        NucleusLogger.PERSISTENCE.debug(Localiser.msg("052207", op.getObjectAsPrintable(), table));
    }
    try {
        VersionMetaData vermd = table.getVersionMetaData();
        RDBMSStoreManager storeMgr = table.getStoreManager();
        if (vermd != null && vermd.getFieldName() != null) {
            // Version field - Update the version in the object
            AbstractMemberMetaData verfmd = ((AbstractClassMetaData) vermd.getParent()).getMetaDataForMember(vermd.getFieldName());
            Object currentVersion = op.getVersion();
            if (currentVersion instanceof Number) {
                // Cater for Integer based versions
                currentVersion = Long.valueOf(((Number) currentVersion).longValue());
            }
            Object nextOptimisticVersion = ec.getLockManager().getNextVersion(vermd, currentVersion);
            if (verfmd.getType() == Integer.class || verfmd.getType() == int.class) {
                // Cater for Integer based versions
                nextOptimisticVersion = Integer.valueOf(((Number) nextOptimisticVersion).intValue());
            }
            op.replaceField(verfmd.getAbsoluteFieldNumber(), nextOptimisticVersion);
        }
        // Set the state to "inserting" (may already be at this state if multiple inheritance level INSERT)
        op.changeActivityState(ActivityState.INSERTING);
        SQLController sqlControl = storeMgr.getSQLController();
        ManagedConnection mconn = storeMgr.getConnectionManager().getConnection(ec);
        try {
            PreparedStatement ps = sqlControl.getStatementForUpdate(mconn, insertStmt, batch, hasIdentityColumn && storeMgr.getDatastoreAdapter().supportsOption(DatastoreAdapter.GET_GENERATED_KEYS_STATEMENT));
            try {
                StatementClassMapping mappingDefinition = new StatementClassMapping();
                StatementMappingIndex[] idxs = stmtMappings;
                for (int i = 0; i < idxs.length; i++) {
                    if (idxs[i] != null) {
                        mappingDefinition.addMappingForMember(i, idxs[i]);
                    }
                }
                // Provide the primary key field(s)
                if (table.getIdentityType() == IdentityType.DATASTORE) {
                    if (!table.isObjectIdDatastoreAttributed() || !table.isBaseDatastoreClass()) {
                        int[] paramNumber = { IDPARAMNUMBER };
                        table.getSurrogateMapping(SurrogateColumnType.DATASTORE_ID, false).setObject(ec, ps, paramNumber, op.getInternalObjectId());
                    }
                } else if (table.getIdentityType() == IdentityType.APPLICATION) {
                    op.provideFields(pkFieldNumbers, new ParameterSetter(op, ps, mappingDefinition));
                }
                // This provides "persistence-by-reachability" for these fields
                if (insertFieldNumbers.length > 0) {
                    // TODO Support surrogate current-user, create-timestamp
                    int numberOfFieldsToProvide = 0;
                    for (int i = 0; i < insertFieldNumbers.length; i++) {
                        if (insertFieldNumbers[i] < op.getClassMetaData().getMemberCount()) {
                            AbstractMemberMetaData mmd = op.getClassMetaData().getMetaDataForManagedMemberAtAbsolutePosition(insertFieldNumbers[i]);
                            if (mmd.isCreateTimestamp()) {
                                // Set create timestamp to time for the start of this transaction
                                op.replaceField(insertFieldNumbers[i], new Timestamp(ec.getTransaction().getIsActive() ? ec.getTransaction().getBeginTime() : System.currentTimeMillis()));
                            } else if (mmd.isCreateUser()) {
                                // Set create user to current user
                                op.replaceField(insertFieldNumbers[i], ec.getNucleusContext().getCurrentUser(ec));
                            }
                            numberOfFieldsToProvide++;
                        }
                    }
                    int j = 0;
                    int[] fieldNums = new int[numberOfFieldsToProvide];
                    for (int i = 0; i < insertFieldNumbers.length; i++) {
                        if (insertFieldNumbers[i] < op.getClassMetaData().getMemberCount()) {
                            fieldNums[j++] = insertFieldNumbers[i];
                        }
                    }
                    op.provideFields(fieldNums, new ParameterSetter(op, ps, mappingDefinition));
                }
                JavaTypeMapping versionMapping = table.getSurrogateMapping(SurrogateColumnType.VERSION, false);
                if (versionMapping != null) {
                    // Surrogate version - set the new version for the object
                    Object currentVersion = op.getVersion();
                    Object nextOptimisticVersion = ec.getLockManager().getNextVersion(vermd, currentVersion);
                    for (int k = 0; k < versionStmtMapping.getNumberOfParameterOccurrences(); k++) {
                        versionMapping.setObject(ec, ps, versionStmtMapping.getParameterPositionsForOccurrence(k), nextOptimisticVersion);
                    }
                    op.setTransactionalVersion(nextOptimisticVersion);
                } else if (vermd != null && vermd.getFieldName() != null) {
                    // Version field - set the new version for the object
                    Object currentVersion = op.getVersion();
                    Object nextOptimisticVersion = ec.getLockManager().getNextVersion(vermd, currentVersion);
                    op.setTransactionalVersion(nextOptimisticVersion);
                }
                if (multitenancyStmtMapping != null) {
                    // Multitenancy mapping
                    table.getSurrogateMapping(SurrogateColumnType.MULTITENANCY, false).setObject(ec, ps, multitenancyStmtMapping.getParameterPositionsForOccurrence(0), ec.getNucleusContext().getMultiTenancyId(ec, op.getClassMetaData()));
                }
                if (softDeleteStmtMapping != null) {
                    // Soft-Delete mapping
                    table.getSurrogateMapping(SurrogateColumnType.SOFTDELETE, false).setObject(ec, ps, softDeleteStmtMapping.getParameterPositionsForOccurrence(0), Boolean.FALSE);
                }
                JavaTypeMapping discrimMapping = table.getSurrogateMapping(SurrogateColumnType.DISCRIMINATOR, false);
                if (discrimMapping != null) {
                    // Discriminator mapping
                    Object discVal = op.getClassMetaData().getDiscriminatorValue();
                    for (int k = 0; k < discriminatorStmtMapping.getNumberOfParameterOccurrences(); k++) {
                        discrimMapping.setObject(ec, ps, discriminatorStmtMapping.getParameterPositionsForOccurrence(k), discVal);
                    }
                }
                // External FK columns (optional)
                if (externalFKStmtMappings != null) {
                    for (int i = 0; i < externalFKStmtMappings.length; i++) {
                        Object fkValue = op.getAssociatedValue(externalFKStmtMappings[i].getMapping());
                        if (fkValue != null) {
                            // Need to provide the owner field number so PCMapping can work out if it is inserted yet
                            AbstractMemberMetaData ownerFmd = table.getMetaDataForExternalMapping(externalFKStmtMappings[i].getMapping(), MappingType.EXTERNAL_FK);
                            for (int k = 0; k < externalFKStmtMappings[i].getNumberOfParameterOccurrences(); k++) {
                                externalFKStmtMappings[i].getMapping().setObject(ec, ps, externalFKStmtMappings[i].getParameterPositionsForOccurrence(k), fkValue, null, ownerFmd.getAbsoluteFieldNumber());
                            }
                        } else {
                            // We're inserting a null so don't need the owner field
                            for (int k = 0; k < externalFKStmtMappings[i].getNumberOfParameterOccurrences(); k++) {
                                externalFKStmtMappings[i].getMapping().setObject(ec, ps, externalFKStmtMappings[i].getParameterPositionsForOccurrence(k), null);
                            }
                        }
                    }
                }
                // External FK discriminator columns (optional)
                if (externalFKDiscrimStmtMappings != null) {
                    for (int i = 0; i < externalFKDiscrimStmtMappings.length; i++) {
                        Object discrimValue = op.getAssociatedValue(externalFKDiscrimStmtMappings[i].getMapping());
                        for (int k = 0; k < externalFKDiscrimStmtMappings[i].getNumberOfParameterOccurrences(); k++) {
                            externalFKDiscrimStmtMappings[i].getMapping().setObject(ec, ps, externalFKDiscrimStmtMappings[i].getParameterPositionsForOccurrence(k), discrimValue);
                        }
                    }
                }
                // External order columns (optional)
                if (externalOrderStmtMappings != null) {
                    for (int i = 0; i < externalOrderStmtMappings.length; i++) {
                        Object orderValue = op.getAssociatedValue(externalOrderStmtMappings[i].getMapping());
                        if (orderValue == null) {
                            // No order value so use -1
                            orderValue = Integer.valueOf(-1);
                        }
                        for (int k = 0; k < externalOrderStmtMappings[i].getNumberOfParameterOccurrences(); k++) {
                            externalOrderStmtMappings[i].getMapping().setObject(ec, ps, externalOrderStmtMappings[i].getParameterPositionsForOccurrence(k), orderValue);
                        }
                    }
                }
                sqlControl.executeStatementUpdate(ec, mconn, insertStmt, ps, !batch);
                if (hasIdentityColumn) {
                    // Identity was set in the datastore using auto-increment/identity/serial etc
                    Object newId = getInsertedDatastoreIdentity(ec, sqlControl, op, mconn, ps);
                    if (NucleusLogger.DATASTORE_PERSIST.isDebugEnabled()) {
                        NucleusLogger.DATASTORE_PERSIST.debug(Localiser.msg("052206", op.getObjectAsPrintable(), newId));
                    }
                    op.setPostStoreNewObjectId(newId);
                }
                // Execute any mapping actions on the insert of the fields (e.g Oracle CLOBs/BLOBs)
                for (int i = 0; i < callbacks.length; ++i) {
                    if (NucleusLogger.PERSISTENCE.isDebugEnabled()) {
                        NucleusLogger.PERSISTENCE.debug(Localiser.msg("052222", op.getObjectAsPrintable(), ((JavaTypeMapping) callbacks[i]).getMemberMetaData().getFullFieldName()));
                    }
                    callbacks[i].insertPostProcessing(op);
                }
                // Update the insert status for this table via the StoreManager
                storeMgr.setObjectIsInsertedToLevel(op, table);
                // (if we did it the other way around we would get a NotYetFlushedException thrown above).
                for (int i = 0; i < relationFieldNumbers.length; i++) {
                    Object value = op.provideField(relationFieldNumbers[i]);
                    if (value != null && ec.getApiAdapter().isDetached(value)) {
                        Object valueAttached = ec.persistObjectInternal(value, null, -1, ObjectProvider.PC);
                        op.replaceField(relationFieldNumbers[i], valueAttached);
                    }
                }
                // Perform reachability on all fields that have no datastore column (1-1 bi non-owner, N-1 bi join)
                if (reachableFieldNumbers.length > 0) {
                    int numberOfReachableFields = 0;
                    for (int i = 0; i < reachableFieldNumbers.length; i++) {
                        if (reachableFieldNumbers[i] < op.getClassMetaData().getMemberCount()) {
                            numberOfReachableFields++;
                        }
                    }
                    int[] fieldNums = new int[numberOfReachableFields];
                    int j = 0;
                    for (int i = 0; i < reachableFieldNumbers.length; i++) {
                        if (reachableFieldNumbers[i] < op.getClassMetaData().getMemberCount()) {
                            fieldNums[j++] = reachableFieldNumbers[i];
                        }
                    }
                    mappingDefinition = new StatementClassMapping();
                    idxs = retrievedStmtMappings;
                    for (int i = 0; i < idxs.length; i++) {
                        if (idxs[i] != null) {
                            mappingDefinition.addMappingForMember(i, idxs[i]);
                        }
                    }
                    NucleusLogger.PERSISTENCE.debug("Performing reachability on fields " + StringUtils.intArrayToString(fieldNums));
                    op.provideFields(fieldNums, new ParameterSetter(op, ps, mappingDefinition));
                }
            } finally {
                sqlControl.closeStatement(mconn, ps);
            }
        } finally {
            mconn.release();
        }
    } catch (SQLException e) {
        String msg = Localiser.msg("052208", op.getObjectAsPrintable(), insertStmt, e.getMessage());
        NucleusLogger.DATASTORE_PERSIST.warn(msg);
        List exceptions = new ArrayList();
        exceptions.add(e);
        while ((e = e.getNextException()) != null) {
            exceptions.add(e);
        }
        throw new NucleusDataStoreException(msg, (Throwable[]) exceptions.toArray(new Throwable[exceptions.size()]));
    }
    // (things like inserting any association parent-child).
    for (int i = 0; i < callbacks.length; ++i) {
        try {
            if (NucleusLogger.PERSISTENCE.isDebugEnabled()) {
                NucleusLogger.PERSISTENCE.debug(Localiser.msg("052209", op.getObjectAsPrintable(), ((JavaTypeMapping) callbacks[i]).getMemberMetaData().getFullFieldName()));
            }
            callbacks[i].postInsert(op);
        } catch (NotYetFlushedException e) {
            op.updateFieldAfterInsert(e.getPersistable(), ((JavaTypeMapping) callbacks[i]).getMemberMetaData().getAbsoluteFieldNumber());
        }
    }
}

Example 7 with ManagedConnection

use of org.datanucleus.store.connection.ManagedConnection in project datanucleus-rdbms by datanucleus.

the class LocateBulkRequest method execute.

/**
 * Method performing the location of the records in the datastore.
 * @param ops ObjectProviders to be located
 * @throws NucleusObjectNotFoundException with nested exceptions for each of missing objects (if any)
 */
public void execute(ObjectProvider[] ops) {
    if (ops == null || ops.length == 0) {
        return;
    }
    if (NucleusLogger.PERSISTENCE.isDebugEnabled()) {
        // Debug information about what we are retrieving
        StringBuilder str = new StringBuilder();
        for (int i = 0; i < ops.length; i++) {
            if (i > 0) {
                str.append(", ");
            }
            str.append(ops[i].getInternalObjectId());
        }
        NucleusLogger.PERSISTENCE.debug(Localiser.msg("052223", str.toString(), table));
    }
    ExecutionContext ec = ops[0].getExecutionContext();
    RDBMSStoreManager storeMgr = table.getStoreManager();
    AbstractClassMetaData cmd = ops[0].getClassMetaData();
    boolean locked = ec.getSerializeReadForClass(cmd.getFullClassName());
    LockMode lockType = ec.getLockManager().getLockMode(ops[0].getInternalObjectId());
    if (lockType != LockMode.LOCK_NONE) {
        if (lockType == LockMode.LOCK_PESSIMISTIC_READ || lockType == LockMode.LOCK_PESSIMISTIC_WRITE) {
            // Override with pessimistic lock
            locked = true;
        }
    }
    String statement = getStatement(table, ops, locked);
    try {
        ManagedConnection mconn = storeMgr.getConnectionManager().getConnection(ec);
        SQLController sqlControl = storeMgr.getSQLController();
        try {
            PreparedStatement ps = sqlControl.getStatementForQuery(mconn, statement);
            try {
                // Provide the primary key field(s)
                for (int i = 0; i < ops.length; i++) {
                    if (cmd.getIdentityType() == IdentityType.DATASTORE) {
                        StatementMappingIndex datastoreIdx = mappingDefinitions[i].getMappingForMemberPosition(SurrogateColumnType.DATASTORE_ID.getFieldNumber());
                        for (int j = 0; j < datastoreIdx.getNumberOfParameterOccurrences(); j++) {
                            table.getSurrogateMapping(SurrogateColumnType.DATASTORE_ID, false).setObject(ec, ps, datastoreIdx.getParameterPositionsForOccurrence(j), ops[i].getInternalObjectId());
                        }
                    } else if (cmd.getIdentityType() == IdentityType.APPLICATION) {
                        ops[i].provideFields(cmd.getPKMemberPositions(), new ParameterSetter(ops[i], ps, mappingDefinitions[i]));
                    }
                }
                // Execute the statement
                ResultSet rs = sqlControl.executeStatementQuery(ec, mconn, statement, ps);
                try {
                    ObjectProvider[] missingOps = processResults(rs, ops);
                    if (missingOps != null && missingOps.length > 0) {
                        NucleusObjectNotFoundException[] nfes = new NucleusObjectNotFoundException[missingOps.length];
                        for (int i = 0; i < nfes.length; i++) {
                            nfes[i] = new NucleusObjectNotFoundException("Object not found", missingOps[i].getInternalObjectId());
                        }
                        throw new NucleusObjectNotFoundException("Some objects were not found. Look at nested exceptions for details", nfes);
                    }
                } finally {
                    rs.close();
                }
            } finally {
                sqlControl.closeStatement(mconn, ps);
            }
        } finally {
            mconn.release();
        }
    } catch (SQLException sqle) {
        String msg = Localiser.msg("052220", ops[0].getObjectAsPrintable(), statement, sqle.getMessage());
        NucleusLogger.DATASTORE_RETRIEVE.warn(msg);
        List exceptions = new ArrayList();
        exceptions.add(sqle);
        while ((sqle = sqle.getNextException()) != null) {
            exceptions.add(sqle);
        }
        throw new NucleusDataStoreException(msg, (Throwable[]) exceptions.toArray(new Throwable[exceptions.size()]));
    }
}

Example 8 with ManagedConnection

use of org.datanucleus.store.connection.ManagedConnection in project datanucleus-rdbms by datanucleus.

the class FKArrayStore method clear.

/**
 * Method to clear the Array.
 * This is called when the container object is being deleted and the elements are to be removed (maybe for dependent field).
 * @param ownerOP The ObjectProvider
 */
public void clear(ObjectProvider ownerOP) {
    boolean deleteElements = false;
    if (ownerMemberMetaData.getArray().isDependentElement()) {
        // Elements are dependent and can't exist on their own, so delete them all
        NucleusLogger.DATASTORE.debug(Localiser.msg("056034"));
        deleteElements = true;
    } else {
        if (ownerMapping.isNullable() && orderMapping.isNullable()) {
            // Field is not dependent, and nullable so we null the FK
            NucleusLogger.DATASTORE.debug(Localiser.msg("056036"));
            deleteElements = false;
        } else {
            // Field is not dependent, and not nullable so we just delete the elements
            NucleusLogger.DATASTORE.debug(Localiser.msg("056035"));
            deleteElements = true;
        }
    }
    if (deleteElements) {
        // Make sure the field is loaded
        ownerOP.isLoaded(ownerMemberMetaData.getAbsoluteFieldNumber());
        Object[] value = (Object[]) ownerOP.provideField(ownerMemberMetaData.getAbsoluteFieldNumber());
        if (value != null && value.length > 0) {
            ownerOP.getExecutionContext().deleteObjects(value);
        }
    } else {
        boolean ownerSoftDelete = ownerOP.getClassMetaData().hasExtension(MetaData.EXTENSION_CLASS_SOFTDELETE);
        if (!ownerSoftDelete) {
            // TODO Cater for multiple element roots
            // TODO If the relation is bidirectional we need to clear the owner in the element
            String clearNullifyStmt = getClearNullifyStmt();
            try {
                ExecutionContext ec = ownerOP.getExecutionContext();
                ManagedConnection mconn = storeMgr.getConnectionManager().getConnection(ec);
                SQLController sqlControl = storeMgr.getSQLController();
                try {
                    PreparedStatement ps = sqlControl.getStatementForUpdate(mconn, clearNullifyStmt, false);
                    try {
                        int jdbcPosition = 1;
                        jdbcPosition = BackingStoreHelper.populateOwnerInStatement(ownerOP, ec, ps, jdbcPosition, this);
                        if (relationDiscriminatorMapping != null) {
                            BackingStoreHelper.populateRelationDiscriminatorInStatement(ec, ps, jdbcPosition, this);
                        }
                        sqlControl.executeStatementUpdate(ec, mconn, clearNullifyStmt, ps, true);
                    } finally {
                        sqlControl.closeStatement(mconn, ps);
                    }
                } finally {
                    mconn.release();
                }
            } catch (SQLException e) {
                throw new NucleusDataStoreException(Localiser.msg("056013", clearNullifyStmt), e);
            }
        }
    }
}

Example 9 with ManagedConnection

use of org.datanucleus.store.connection.ManagedConnection in project datanucleus-rdbms by datanucleus.

the class FKArrayStore method iterator.

/**
 * Accessor for an iterator for the set.
 * @param ownerOP ObjectProvider for the set.
 * @return Iterator for the set.
 */
public Iterator<E> iterator(ObjectProvider ownerOP) {
    ExecutionContext ec = ownerOP.getExecutionContext();
    if (elementInfo == null || elementInfo.length == 0) {
        return null;
    }
    // Generate the statement, and statement mapping/parameter information
    IteratorStatement iterStmt = getIteratorStatement(ownerOP.getExecutionContext(), ownerOP.getExecutionContext().getFetchPlan(), true);
    SelectStatement sqlStmt = iterStmt.getSelectStatement();
    StatementClassMapping iteratorMappingDef = iterStmt.getStatementClassMapping();
    // Input parameter(s) - the owner
    int inputParamNum = 1;
    StatementMappingIndex ownerIdx = new StatementMappingIndex(ownerMapping);
    if (sqlStmt.getNumberOfUnions() > 0) {
        // Add parameter occurrence for each union of statement
        for (int j = 0; j < sqlStmt.getNumberOfUnions() + 1; j++) {
            int[] paramPositions = new int[ownerMapping.getNumberOfDatastoreMappings()];
            for (int k = 0; k < ownerMapping.getNumberOfDatastoreMappings(); k++) {
                paramPositions[k] = inputParamNum++;
            }
            ownerIdx.addParameterOccurrence(paramPositions);
        }
    } else {
        int[] paramPositions = new int[ownerMapping.getNumberOfDatastoreMappings()];
        for (int k = 0; k < ownerMapping.getNumberOfDatastoreMappings(); k++) {
            paramPositions[k] = inputParamNum++;
        }
        ownerIdx.addParameterOccurrence(paramPositions);
    }
    StatementParameterMapping iteratorMappingParams = new StatementParameterMapping();
    iteratorMappingParams.addMappingForParameter("owner", ownerIdx);
    if (ec.getTransaction().getSerializeRead() != null && ec.getTransaction().getSerializeRead()) {
        sqlStmt.addExtension(SQLStatement.EXTENSION_LOCK_FOR_UPDATE, true);
    }
    String stmt = sqlStmt.getSQLText().toSQL();
    try {
        ManagedConnection mconn = storeMgr.getConnectionManager().getConnection(ec);
        SQLController sqlControl = storeMgr.getSQLController();
        try {
            // Create the statement
            PreparedStatement ps = sqlControl.getStatementForQuery(mconn, stmt);
            // Set the owner
            ObjectProvider stmtOwnerOP = BackingStoreHelper.getOwnerObjectProviderForBackingStore(ownerOP);
            int numParams = ownerIdx.getNumberOfParameterOccurrences();
            for (int paramInstance = 0; paramInstance < numParams; paramInstance++) {
                ownerIdx.getMapping().setObject(ec, ps, ownerIdx.getParameterPositionsForOccurrence(paramInstance), stmtOwnerOP.getObject());
            }
            try {
                ResultSet rs = sqlControl.executeStatementQuery(ec, mconn, stmt, ps);
                try {
                    ResultObjectFactory rof = null;
                    if (elementsAreEmbedded || elementsAreSerialised) {
                        throw new NucleusException("Cannot have FK array with non-persistent objects");
                    }
                    rof = new PersistentClassROF(ec, rs, false, iteratorMappingDef, elementCmd, clr.classForName(elementType));
                    return new ArrayStoreIterator(ownerOP, rs, rof, this);
                } finally {
                    rs.close();
                }
            } finally {
                sqlControl.closeStatement(mconn, ps);
            }
        } finally {
            mconn.release();
        }
    } catch (SQLException | MappedDatastoreException e) {
        throw new NucleusDataStoreException(Localiser.msg("056006", stmt), e);
    }
}

Example 10 with ManagedConnection

use of org.datanucleus.store.connection.ManagedConnection in project datanucleus-rdbms by datanucleus.

the class FKListStore method internalAdd.

/**
 * Internal method for adding an item to the List.
 * @param ownerOP ObjectProvider for the owner
 * @param startAt The start position
 * @param atEnd Whether to add at the end
 * @param c The Collection of elements to add.
 * @param size Current size of list (if known). -1 if not known
 * @return Whether it was successful
 */
protected boolean internalAdd(ObjectProvider ownerOP, int startAt, boolean atEnd, Collection<E> c, int size) {
    if (c == null || c.size() == 0) {
        return true;
    }
    // Check what we have persistent already
    int currentListSize = (size < 0 ? size(ownerOP) : size);
    boolean shiftingElements = true;
    if (atEnd || startAt == currentListSize) {
        shiftingElements = false;
        // Not shifting so we insert from the end
        startAt = currentListSize;
    }
    boolean elementsNeedPositioning = false;
    int position = startAt;
    Iterator elementIter = c.iterator();
    while (elementIter.hasNext()) {
        // Persist any non-persistent objects optionally at their final list position (persistence-by-reachability)
        if (shiftingElements) {
            // We have to shift things so dont bother with positioning
            position = -1;
        }
        boolean inserted = validateElementForWriting(ownerOP, elementIter.next(), position);
        if (!inserted || shiftingElements) {
            // This element wasnt positioned in the validate so we need to set the positions later
            elementsNeedPositioning = true;
        }
        if (!shiftingElements) {
            position++;
        }
    }
    if (shiftingElements) {
        // all ids after the position we insert at
        try {
            // Calculate the amount we need to shift any existing elements by
            // This is used where inserting between existing elements and have to shift down all elements after the start point
            int shift = c.size();
            ExecutionContext ec = ownerOP.getExecutionContext();
            ManagedConnection mconn = storeMgr.getConnectionManager().getConnection(ec);
            try {
                // shift up existing elements after start position by "shift"
                for (int i = currentListSize - 1; i >= startAt; i--) {
                    // Shift the index of this row by "shift"
                    internalShift(ownerOP, mconn, true, i, shift, false);
                }
            } finally {
                mconn.release();
            }
        } catch (MappedDatastoreException e) {
            // An error was encountered during the shift process so abort here
            throw new NucleusDataStoreException(Localiser.msg("056009", e.getMessage()), e.getCause());
        }
    }
    if (shiftingElements || elementsNeedPositioning) {
        // Some elements have been shifted so the new elements need positioning now, or we already had some
        // of the new elements persistent and so they need their positions setting now
        elementIter = c.iterator();
        while (elementIter.hasNext()) {
            Object element = elementIter.next();
            updateElementFk(ownerOP, element, ownerOP.getObject(), startAt);
            startAt++;
        }
    }
    return true;
}