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/*
* 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.spark.sql.sources.v2;
import java.io.IOException;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import java.util.Optional;
import java.util.stream.Stream;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.apache.spark.annotation.InterfaceStability;
/**
* An immutable string-to-string map in which keys are case-insensitive. This is used to represent
* data source options.
*
* Each data source implementation can define its own options and teach its users how to set them.
* Spark doesn't have any restrictions about what options a data source should or should not have.
* Instead Spark defines some standard options that data sources can optionally adopt. It's possible
* that some options are very common and many data sources use them. However different data
* sources may define the common options(key and meaning) differently, which is quite confusing to
* end users.
*
* The standard options defined by Spark:
*
*
*
Option key
*
Option value
*
*
*
path
*
A path string of the data files/directories, like
* path1, /absolute/file2, path3/*. The path can
* either be relative or absolute, points to either file or directory, and can contain
* wildcards. This option is commonly used by file-based data sources.
*
*
*
paths
*
A JSON array style paths string of the data files/directories, like
* ["path1", "/absolute/file2"]. The format of each path is same as the
* path option, plus it should follow JSON string literal format, e.g. quotes
* should be escaped, pa\"th means pa"th.
*
*
*
*
table
*
A table name string representing the table name directly without any interpretation.
* For example, db.tbl means a table called db.tbl, not a table called tbl
* inside database db. `t*b.l` means a table called `t*b.l`, not t*b.l.
*
*
*
database
*
A database name string representing the database name directly without any
* interpretation, which is very similar to the table name option.
*
*
*/
@InterfaceStability.Evolving
public class DataSourceOptions {
private final Map keyLowerCasedMap;
private String toLowerCase(String key) {
return key.toLowerCase(Locale.ROOT);
}
public static DataSourceOptions empty() {
return new DataSourceOptions(new HashMap<>());
}
public DataSourceOptions(Map originalMap) {
keyLowerCasedMap = new HashMap<>(originalMap.size());
for (Map.Entry entry : originalMap.entrySet()) {
keyLowerCasedMap.put(toLowerCase(entry.getKey()), entry.getValue());
}
}
public Map asMap() {
return new HashMap<>(keyLowerCasedMap);
}
/**
* Returns the option value to which the specified key is mapped, case-insensitively.
*/
public Optional get(String key) {
return Optional.ofNullable(keyLowerCasedMap.get(toLowerCase(key)));
}
/**
* Returns the boolean value to which the specified key is mapped,
* or defaultValue if there is no mapping for the key. The key match is case-insensitive
*/
public boolean getBoolean(String key, boolean defaultValue) {
String lcaseKey = toLowerCase(key);
return keyLowerCasedMap.containsKey(lcaseKey) ?
Boolean.parseBoolean(keyLowerCasedMap.get(lcaseKey)) : defaultValue;
}
/**
* Returns the integer value to which the specified key is mapped,
* or defaultValue if there is no mapping for the key. The key match is case-insensitive
*/
public int getInt(String key, int defaultValue) {
String lcaseKey = toLowerCase(key);
return keyLowerCasedMap.containsKey(lcaseKey) ?
Integer.parseInt(keyLowerCasedMap.get(lcaseKey)) : defaultValue;
}
/**
* Returns the long value to which the specified key is mapped,
* or defaultValue if there is no mapping for the key. The key match is case-insensitive
*/
public long getLong(String key, long defaultValue) {
String lcaseKey = toLowerCase(key);
return keyLowerCasedMap.containsKey(lcaseKey) ?
Long.parseLong(keyLowerCasedMap.get(lcaseKey)) : defaultValue;
}
/**
* Returns the double value to which the specified key is mapped,
* or defaultValue if there is no mapping for the key. The key match is case-insensitive
*/
public double getDouble(String key, double defaultValue) {
String lcaseKey = toLowerCase(key);
return keyLowerCasedMap.containsKey(lcaseKey) ?
Double.parseDouble(keyLowerCasedMap.get(lcaseKey)) : defaultValue;
}
/**
* The option key for singular path.
*/
public static final String PATH_KEY = "path";
/**
* The option key for multiple paths.
*/
public static final String PATHS_KEY = "paths";
/**
* The option key for table name.
*/
public static final String TABLE_KEY = "table";
/**
* The option key for database name.
*/
public static final String DATABASE_KEY = "database";
/**
* Returns all the paths specified by both the singular path option and the multiple
* paths option.
*/
public String[] paths() {
String[] singularPath =
get(PATH_KEY).map(s -> new String[]{s}).orElseGet(() -> new String[0]);
Optional pathsStr = get(PATHS_KEY);
if (pathsStr.isPresent()) {
ObjectMapper objectMapper = new ObjectMapper();
try {
String[] paths = objectMapper.readValue(pathsStr.get(), String[].class);
return Stream.of(singularPath, paths).flatMap(Stream::of).toArray(String[]::new);
} catch (IOException e) {
return singularPath;
}
} else {
return singularPath;
}
}
/**
* Returns the value of the table name option.
*/
public Optional tableName() {
return get(TABLE_KEY);
}
/**
* Returns the value of the database name option.
*/
public Optional databaseName() {
return get(DATABASE_KEY);
}
}
