/*
* 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.kafka;
import com.facebook.presto.kafka.decoder.dummy.DummyKafkaRowDecoder;
import com.facebook.presto.spi.SchemaTableName;
import com.google.common.base.Objects;
import com.google.common.base.Supplier;
import com.google.common.base.Throwables;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.io.Files;
import io.airlift.json.JsonCodec;
import io.airlift.log.Logger;
import javax.inject.Inject;
import java.io.File;
import java.io.IOException;
import java.util.List;
import java.util.Map;
import static com.google.common.base.Preconditions.checkNotNull;
import static java.util.Arrays.asList;
public class KafkaTableDescriptionSupplier
implements Supplier<Map<SchemaTableName, KafkaTopicDescription>>
{
private static final Logger log = Logger.get(KafkaTableDescriptionSupplier.class);
private final KafkaConnectorConfig kafkaConnectorConfig;
private final JsonCodec<KafkaTopicDescription> topicDescriptionCodec;
@Inject
KafkaTableDescriptionSupplier(KafkaConnectorConfig kafkaConnectorConfig,
JsonCodec<KafkaTopicDescription> topicDescriptionCodec)
{
this.kafkaConnectorConfig = checkNotNull(kafkaConnectorConfig, "kafkaConnectorConfig is null");
this.topicDescriptionCodec = checkNotNull(topicDescriptionCodec, "topicDescriptionCodec is null");
}
@Override
public Map<SchemaTableName, KafkaTopicDescription> get()
{
ImmutableMap.Builder<SchemaTableName, KafkaTopicDescription> builder = ImmutableMap.builder();
try {
for (File file : listFiles(kafkaConnectorConfig.getTableDescriptionDir())) {
if (file.isFile() && file.getName().endsWith(".json")) {
KafkaTopicDescription table = topicDescriptionCodec.fromJson(Files.toByteArray(file));
String schemaName = Objects.firstNonNull(table.getSchemaName(), kafkaConnectorConfig.getDefaultSchema());
log.debug("Kafka table %s.%s: %s", schemaName, table.getTableName(), table);
builder.put(new SchemaTableName(schemaName, table.getTableName()), table);
}
}
Map<SchemaTableName, KafkaTopicDescription> tableDefinitions = builder.build();
log.debug("Loaded Table definitions: %s", tableDefinitions.keySet());
builder = ImmutableMap.builder();
for (String definedTable : kafkaConnectorConfig.getTableNames()) {
SchemaTableName tableName;
try {
tableName = SchemaTableName.valueOf(definedTable);
}
catch (IllegalArgumentException iae) {
tableName = new SchemaTableName(kafkaConnectorConfig.getDefaultSchema(), definedTable);
}
if (tableDefinitions.containsKey(tableName)) {
KafkaTopicDescription kafkaTable = tableDefinitions.get(tableName);
log.debug("Found Table definition for %s: %s", tableName, kafkaTable);
builder.put(tableName, kafkaTable);
}
else {
// A dummy table definition only supports the internal columns.
log.debug("Created dummy Table definition for %s", tableName);
builder.put(tableName, new KafkaTopicDescription(tableName.getTableName(),
tableName.getSchemaName(),
definedTable,
new KafkaTopicFieldGroup(DummyKafkaRowDecoder.NAME, ImmutableList.<KafkaTopicFieldDescription>of()),
new KafkaTopicFieldGroup(DummyKafkaRowDecoder.NAME, ImmutableList.<KafkaTopicFieldDescription>of())));
}
}
return builder.build();
}
catch (IOException e) {
log.warn(e, "Error: ");
throw Throwables.propagate(e);
}
}
private static List<File> listFiles(File dir)
{
if ((dir != null) && dir.isDirectory()) {
File[] files = dir.listFiles();
if (files != null) {
log.debug("Considering files: %s", asList(files));
return ImmutableList.copyOf(files);
}
}
return ImmutableList.of();
}
}