Java tutorial
/* * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.facebook.presto.metadata; import com.facebook.presto.Session; import com.facebook.presto.connector.ConnectorId; import com.facebook.presto.spi.ErrorCodeSupplier; import com.facebook.presto.spi.PrestoException; import com.facebook.presto.spi.block.BlockBuilder; import com.facebook.presto.spi.block.BlockBuilderStatus; import com.facebook.presto.spi.session.PropertyMetadata; import com.facebook.presto.spi.type.Type; import com.facebook.presto.sql.analyzer.SemanticException; import com.facebook.presto.sql.planner.ParameterRewriter; import com.facebook.presto.sql.tree.Expression; import com.facebook.presto.sql.tree.ExpressionTreeRewriter; import com.google.common.collect.ImmutableMap; import com.google.common.collect.Maps; import java.util.List; import java.util.Map; import java.util.concurrent.ConcurrentHashMap; import java.util.concurrent.ConcurrentMap; import static com.facebook.presto.spi.StandardErrorCode.NOT_FOUND; import static com.facebook.presto.spi.type.TypeUtils.writeNativeValue; import static com.facebook.presto.sql.planner.ExpressionInterpreter.evaluateConstantExpression; import static com.google.common.base.Preconditions.checkState; import static java.lang.String.format; import static java.util.Locale.ENGLISH; import static java.util.Objects.requireNonNull; abstract class AbstractPropertyManager { private final ConcurrentMap<ConnectorId, Map<String, PropertyMetadata<?>>> connectorProperties = new ConcurrentHashMap<>(); private final String propertyType; private final ErrorCodeSupplier propertyError; protected AbstractPropertyManager(String propertyType, ErrorCodeSupplier propertyError) { requireNonNull(propertyType, "propertyType is null"); this.propertyType = propertyType; this.propertyError = requireNonNull(propertyError, "propertyError is null"); } public final void addProperties(ConnectorId connectorId, List<PropertyMetadata<?>> properties) { requireNonNull(connectorId, "connectorId is null"); requireNonNull(properties, "properties is null"); Map<String, PropertyMetadata<?>> propertiesByName = Maps.uniqueIndex(properties, PropertyMetadata::getName); checkState(connectorProperties.putIfAbsent(connectorId, propertiesByName) == null, "Properties for connector '%s' are already registered", connectorId); } public final void removeProperties(ConnectorId connectorId) { connectorProperties.remove(connectorId); } public final Map<String, Object> getProperties(ConnectorId connectorId, String catalog, // only use this for error messages Map<String, Expression> sqlPropertyValues, Session session, Metadata metadata, List<Expression> parameters) { Map<String, PropertyMetadata<?>> supportedProperties = connectorProperties.get(connectorId); if (supportedProperties == null) { throw new PrestoException(NOT_FOUND, "Catalog not found: " + catalog); } ImmutableMap.Builder<String, Object> properties = ImmutableMap.builder(); // Fill in user-specified properties for (Map.Entry<String, Expression> sqlProperty : sqlPropertyValues.entrySet()) { String propertyName = sqlProperty.getKey().toLowerCase(ENGLISH); PropertyMetadata<?> property = supportedProperties.get(propertyName); if (property == null) { throw new PrestoException(propertyError, format("Catalog '%s' does not support %s property '%s'", catalog, propertyType, propertyName)); } Object sqlObjectValue; try { sqlObjectValue = evaluatePropertyValue(sqlProperty.getValue(), property.getSqlType(), session, metadata, parameters); } catch (SemanticException e) { throw new PrestoException( propertyError, format("Invalid value for %s property '%s': Cannot convert '%s' to %s", propertyType, property.getName(), sqlProperty.getValue(), property.getSqlType()), e); } Object value; try { value = property.decode(sqlObjectValue); } catch (Exception e) { throw new PrestoException(propertyError, format("Unable to set %s property '%s' to '%s': %s", propertyType, property.getName(), sqlProperty.getValue(), e.getMessage()), e); } properties.put(property.getName(), value); } Map<String, Object> userSpecifiedProperties = properties.build(); // Fill in the remaining properties with non-null defaults for (PropertyMetadata<?> propertyMetadata : supportedProperties.values()) { if (!userSpecifiedProperties.containsKey(propertyMetadata.getName())) { Object value = propertyMetadata.getDefaultValue(); if (value != null) { properties.put(propertyMetadata.getName(), value); } } } return properties.build(); } public Map<ConnectorId, Map<String, PropertyMetadata<?>>> getAllProperties() { return ImmutableMap.copyOf(connectorProperties); } private Object evaluatePropertyValue(Expression expression, Type expectedType, Session session, Metadata metadata, List<Expression> parameters) { Expression rewritten = ExpressionTreeRewriter.rewriteWith(new ParameterRewriter(parameters), expression); Object value = evaluateConstantExpression(rewritten, expectedType, metadata, session, parameters); // convert to object value type of SQL type BlockBuilder blockBuilder = expectedType.createBlockBuilder(new BlockBuilderStatus(), 1); writeNativeValue(expectedType, blockBuilder, value); Object objectValue = expectedType.getObjectValue(session.toConnectorSession(), blockBuilder, 0); if (objectValue == null) { throw new PrestoException(propertyError, format("Invalid null value for %s property", propertyType)); } return objectValue; } }