Java Code Examples for org.apache.accumulo.core.client.ConditionalWriter#write()

@Override
public void update(final RyaDetails oldDetails, final RyaDetails newDetails)
        throws NotInitializedException, ConcurrentUpdateException, RyaDetailsRepositoryException {
    // Preconditions.
    requireNonNull(oldDetails);
    requireNonNull(newDetails);

    if(!newDetails.getRyaInstanceName().equals( instanceName )) {
        throw new RyaDetailsRepositoryException("The instance name that was in the provided 'newDetails' does not match " +
                "the instance name that this repository is connected to. Make sure you're connected to the" +
                "correct Rya instance.");
    }

    if(!isInitialized()) {
        throw new NotInitializedException("Could not update the details for the Rya instanced named '" +
                instanceName + "' because it has not been initialized yet.");
    }

    // Use a conditional writer so that we can detect when the old details
    // are no longer the currently stored ones.
    ConditionalWriter writer = null;
    try {
        // Setup the condition that ensures the details have not changed since the edits were made.
        final byte[] oldDetailsBytes = serializer.serialize(oldDetails);
        final Condition condition = new Condition(COL_FAMILY, COL_QUALIFIER);
        condition.setValue( oldDetailsBytes );

        // Create the mutation that only performs the update if the details haven't changed.
        final ConditionalMutation mutation = new ConditionalMutation(ROW_ID);
        mutation.addCondition( condition );
        final byte[] newDetailsBytes = serializer.serialize(newDetails);
        mutation.put(COL_FAMILY, COL_QUALIFIER, new Value(newDetailsBytes));

        // Do the write.
        writer = connector.createConditionalWriter(detailsTableName, new ConditionalWriterConfig());
        final Result result = writer.write(mutation);
        switch(result.getStatus()) {
            case REJECTED:
            case VIOLATED:
                throw new ConcurrentUpdateException("Could not update the details for the Rya instance named '" +
                        instanceName + "' because the old value is out of date.");
            case UNKNOWN:
            case INVISIBLE_VISIBILITY:
                throw new RyaDetailsRepositoryException("Could not update the details for the Rya instance named '" + instanceName + "'.");
        }
    } catch (final TableNotFoundException | AccumuloException | AccumuloSecurityException e) {
        throw new RyaDetailsRepositoryException("Could not update the details for the Rya instance named '" + instanceName + "'.");
    } finally {
        if(writer != null) {
            writer.close();
        }
    }
}
 

/**
 * Update the cardinality of a PCJ by a {@code delta}.
 *
 * @param accumuloConn - A connection to the Accumulo that hosts the PCJ table. (not null)
 * @param pcjTableName - The name of the PCJ table that will have its cardinality updated. (not null)
 * @param delta - How much the cardinality will change.
 * @throws PCJStorageException The cardinality could not be updated.
 */
private void updateCardinality(final Connector accumuloConn, final String pcjTableName, final long delta) throws PCJStorageException {
    checkNotNull(accumuloConn);
    checkNotNull(pcjTableName);

    ConditionalWriter conditionalWriter = null;
    try {
        conditionalWriter = accumuloConn.createConditionalWriter(pcjTableName, new ConditionalWriterConfig());

        boolean updated = false;
        while (!updated) {
            // Write the conditional update request to Accumulo.
            final long cardinality = getPcjMetadata(accumuloConn,pcjTableName).getCardinality();
            final ConditionalMutation mutation = makeUpdateCardinalityMutation(cardinality, delta);
            final ConditionalWriter.Result result = conditionalWriter.write(mutation);

            // Interpret the result.
            switch (result.getStatus()) {
            case ACCEPTED:
                updated = true;
                break;
            case REJECTED:
                break;
            case UNKNOWN:
                // We do not know if the mutation succeeded. At best, we
                // can hope the metadata hasn't been updated
                // since we originally fetched it and try again.
                // Otherwise, continue forwards as if it worked. It's
                // okay if this number is slightly off.
                final long newCardinality = getPcjMetadata(accumuloConn,pcjTableName).getCardinality();
                if (newCardinality != cardinality) {
                    updated = true;
                }
                break;
            case VIOLATED:
                throw new PCJStorageException("The cardinality could not be updated because the commit violated a table constraint.");
            case INVISIBLE_VISIBILITY:
                throw new PCJStorageException("The condition contains a visibility the updater can not satisfy.");
            }
        }
    } catch (AccumuloException | AccumuloSecurityException | TableNotFoundException e) {
        throw new PCJStorageException("Could not update the cardinality value of the PCJ Table named: " + pcjTableName, e);
    } finally {
        if (conditionalWriter != null) {
            conditionalWriter.close();
        }
    }
}