/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.drill.exec.store.mock;
import java.io.IOException;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.apache.calcite.schema.SchemaPlus;
import org.apache.calcite.schema.Table;
import org.apache.drill.common.JSONOptions;
import org.apache.drill.common.expression.SchemaPath;
import org.apache.drill.common.logical.StoragePluginConfig;
import org.apache.drill.exec.physical.base.AbstractGroupScan;
import org.apache.drill.exec.planner.logical.DynamicDrillTable;
import org.apache.drill.exec.server.DrillbitContext;
import org.apache.drill.exec.store.AbstractSchema;
import org.apache.drill.exec.store.AbstractStoragePlugin;
import org.apache.drill.exec.store.SchemaConfig;
import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.google.common.base.Charsets;
import com.google.common.collect.ImmutableList;
import com.google.common.io.Resources;
public class MockStorageEngine extends AbstractStoragePlugin {
static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(MockStorageEngine.class);
private final MockStorageEngineConfig configuration;
private final MockSchema schema;
public MockStorageEngine(MockStorageEngineConfig configuration, DrillbitContext context, String name) {
this.configuration = configuration;
this.schema = new MockSchema(this);
}
@Override
public AbstractGroupScan getPhysicalScan(String userName, JSONOptions selection, List<SchemaPath> columns)
throws IOException {
List<MockTableDef.MockScanEntry> readEntries = selection.getListWith(new ObjectMapper(),
new TypeReference<ArrayList<MockTableDef.MockScanEntry>>() {
});
assert ! readEntries.isEmpty();
return new MockGroupScanPOP(null, readEntries);
}
@Override
public void registerSchemas(SchemaConfig schemaConfig, SchemaPlus parent) throws IOException {
parent.add(schema.getName(), schema);
}
@Override
public StoragePluginConfig getConfig() {
return configuration;
}
@Override
public boolean supportsRead() {
return true;
}
/**
* Resolves table names within the mock data source. Tables can be of two forms:
* <p>
* <tt><name>_<n><unit></tt>
* <p>
* Where the "name" can be anything, "n" is the number of rows, and "unit" is
* the units for the row count: non, K (thousand) or M (million).
* <p>
* The above form generates a table directly with no other information needed.
* Column names must be provided, and must be of the form:
* <p>
* <tt><name>_<type><size></tt>
* <p>
* Where the name can be anything, the type must be i (integer), d (double),
* b (boolean)
* or s (string, AKA VarChar). The length is needed only for string fields.
* <p>
* Direct tables are quick, but limited. The other option is to provide the
* name of a definition file:
* <p>
* <tt><fileName>.json</tt>
* <p>
* In this case, the JSON file must be a resource visible on the class path.
* Omit the leading slash in the resource path name.
*/
private static class MockSchema extends AbstractSchema {
private MockStorageEngine engine;
public MockSchema(MockStorageEngine engine) {
super(ImmutableList.<String>of(), MockStorageEngineConfig.NAME);
this.engine = engine;
}
@Override
public Table getTable(String name) {
if (name.toLowerCase().endsWith(".json")) {
return getConfigFile(name);
} else {
return getDirectTable(name);
}
}
private Table getConfigFile(String name) {
final URL url = Resources.getResource(name);
if (url == null) {
throw new IllegalArgumentException(
"Unable to find mock table config file " + name);
}
MockTableDef mockTableDefn;
try {
String json = Resources.toString(url, Charsets.UTF_8);
final ObjectMapper mapper = new ObjectMapper();
mapper.configure(JsonParser.Feature.ALLOW_UNQUOTED_FIELD_NAMES, true);
mockTableDefn = mapper.readValue(json, MockTableDef.class);
} catch (JsonParseException e) {
throw new IllegalArgumentException("Unable to parse mock table definition file: " + name, e);
} catch (JsonMappingException e) {
throw new IllegalArgumentException("Unable to Jackson deserialize mock table definition file: " + name, e);
} catch (IOException e) {
throw new IllegalArgumentException("Unable to read mock table definition file: " + name, e);
}
return new DynamicDrillTable(engine, this.name, mockTableDefn.getEntries());
}
private Table getDirectTable(String name) {
Pattern p = Pattern.compile("(\\w+)_(\\d+)(k|m)?", Pattern.CASE_INSENSITIVE);
Matcher m = p.matcher(name);
if (! m.matches()) {
return null;
}
@SuppressWarnings("unused")
String baseName = m.group(1);
int n = Integer.parseInt(m.group(2));
String unit = m.group(3);
if (unit == null) { }
else if (unit.equalsIgnoreCase("K")) { n *= 1000; }
else if (unit.equalsIgnoreCase("M")) { n *= 1_000_000; }
MockTableDef.MockScanEntry entry = new MockTableDef.MockScanEntry(n, true, 0, 1, null);
List<MockTableDef.MockScanEntry> list = new ArrayList<>();
list.add(entry);
return new DynamicDrillTable(engine, this.name, list);
}
@Override
public Set<String> getTableNames() {
return new HashSet<>();
}
@Override
public String getTypeName() {
return MockStorageEngineConfig.NAME;
}
}
}