1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
|
/*
* 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.internal.config
import java.util.{Map => JMap}
import scala.util.matching.Regex
import org.apache.spark.SparkConf
/**
* An entry contains all meta information for a configuration.
*
* When applying variable substitution to config values, only references starting with "spark." are
* considered in the default namespace. For known Spark configuration keys (i.e. those created using
* `ConfigBuilder`), references will also consider the default value when it exists.
*
* Variable expansion is also applied to the default values of config entries that have a default
* value declared as a string.
*
* @param key the key for the configuration
* @param defaultValue the default value for the configuration
* @param valueConverter how to convert a string to the value. It should throw an exception if the
* string does not have the required format.
* @param stringConverter how to convert a value to a string that the user can use it as a valid
* string value. It's usually `toString`. But sometimes, a custom converter
* is necessary. E.g., if T is List[String], `a, b, c` is better than
* `List(a, b, c)`.
* @param doc the documentation for the configuration
* @param isPublic if this configuration is public to the user. If it's `false`, this
* configuration is only used internally and we should not expose it to users.
* @tparam T the value type
*/
private[spark] abstract class ConfigEntry[T] (
val key: String,
val valueConverter: String => T,
val stringConverter: T => String,
val doc: String,
val isPublic: Boolean) {
import ConfigEntry._
registerEntry(this)
def defaultValueString: String
def readFrom(reader: ConfigReader): T
def defaultValue: Option[T] = None
override def toString: String = {
s"ConfigEntry(key=$key, defaultValue=$defaultValueString, doc=$doc, public=$isPublic)"
}
}
private class ConfigEntryWithDefault[T] (
key: String,
_defaultValue: T,
valueConverter: String => T,
stringConverter: T => String,
doc: String,
isPublic: Boolean)
extends ConfigEntry(key, valueConverter, stringConverter, doc, isPublic) {
override def defaultValue: Option[T] = Some(_defaultValue)
override def defaultValueString: String = stringConverter(_defaultValue)
def readFrom(reader: ConfigReader): T = {
reader.get(key).map(valueConverter).getOrElse(_defaultValue)
}
}
private class ConfigEntryWithDefaultString[T] (
key: String,
_defaultValue: String,
valueConverter: String => T,
stringConverter: T => String,
doc: String,
isPublic: Boolean)
extends ConfigEntry(key, valueConverter, stringConverter, doc, isPublic) {
override def defaultValue: Option[T] = Some(valueConverter(_defaultValue))
override def defaultValueString: String = _defaultValue
def readFrom(reader: ConfigReader): T = {
val value = reader.get(key).getOrElse(reader.substitute(_defaultValue))
valueConverter(value)
}
}
/**
* A config entry that does not have a default value.
*/
private[spark] class OptionalConfigEntry[T](
key: String,
val rawValueConverter: String => T,
val rawStringConverter: T => String,
doc: String,
isPublic: Boolean)
extends ConfigEntry[Option[T]](key, s => Some(rawValueConverter(s)),
v => v.map(rawStringConverter).orNull, doc, isPublic) {
override def defaultValueString: String = "<undefined>"
override def readFrom(reader: ConfigReader): Option[T] = {
reader.get(key).map(rawValueConverter)
}
}
/**
* A config entry whose default value is defined by another config entry.
*/
private class FallbackConfigEntry[T] (
key: String,
doc: String,
isPublic: Boolean,
private[config] val fallback: ConfigEntry[T])
extends ConfigEntry[T](key, fallback.valueConverter, fallback.stringConverter, doc, isPublic) {
override def defaultValueString: String = s"<value of ${fallback.key}>"
override def readFrom(reader: ConfigReader): T = {
reader.get(key).map(valueConverter).getOrElse(fallback.readFrom(reader))
}
}
private[spark] object ConfigEntry {
private val knownConfigs = new java.util.concurrent.ConcurrentHashMap[String, ConfigEntry[_]]()
def registerEntry(entry: ConfigEntry[_]): Unit = {
val existing = knownConfigs.putIfAbsent(entry.key, entry)
require(existing == null, s"Config entry ${entry.key} already registered!")
}
def findEntry(key: String): ConfigEntry[_] = knownConfigs.get(key)
}
|
