org.rocksdb

枚举 EncodingType

java.lang.Object

java.lang.Enum<EncodingType>

org.rocksdb.EncodingType

所有已实现的接口:

java.io.Serializable, java.lang.Comparable<EncodingType>

public enum EncodingType
extends java.lang.Enum<EncodingType>

EncodingType

The value will determine how to encode keys when writing to a new SST file.

This value will be stored inside the SST file which will be used when reading from the file, which makes it possible for users to choose different encoding type when reopening a DB. Files with different encoding types can co-exist in the same DB and can be read.

枚举常量概要

枚举常量

枚举常量和说明
kPlain Always write full keys without any special encoding.
kPrefix Find opportunity to write the same prefix once for multiple rows.

方法概要

限定符和类型	方法和说明
byte	getValue() Returns the byte value of the enumerations value
static EncodingType	valueOf(java.lang.String name) 返回带有指定名称的该类型的枚举常量。
static EncodingType[]	values() 按照声明该枚举类型的常量的顺序, 返回 包含这些常量的数组。

从类继承的方法 java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

从类继承的方法 java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

枚举常量详细资料

kPlain

public static final EncodingType kPlain

Always write full keys without any special encoding.

kPrefix

public static final EncodingType kPrefix

Find opportunity to write the same prefix once for multiple rows. In some cases, when a key follows a previous key with the same prefix, instead of writing out the full key, it just writes out the size of the shared prefix, as well as other bytes, to save some bytes.

When using this option, the user is required to use the same prefix extractor to make sure the same prefix will be extracted from the same key. The Name() value of the prefix extractor will be stored in the file. When reopening the file, the name of the options.prefix_extractor given will be bitwise compared to the prefix extractors stored in the file. An error will be returned if the two don't match.

方法详细资料

values

public static EncodingType[] values()

按照声明该枚举类型的常量的顺序, 返回 包含这些常量的数组。该方法可用于迭代 常量, 如下所示:

for (EncodingType c : EncodingType.values())
    System.out.println(c);

返回:

按照声明该枚举类型的常量的顺序返回的包含这些常量的数组

valueOf

public static EncodingType valueOf(java.lang.String name)

返回带有指定名称的该类型的枚举常量。 字符串必须与用于声明该类型的枚举常量的 标识符完全匹配。(不允许有多余 的空格字符。)

参数:

name - 要返回的枚举常量的名称。

返回:

返回带有指定名称的枚举常量

抛出:

java.lang.IllegalArgumentException - 如果该枚举类型没有带有指定名称的常量

java.lang.NullPointerException - 如果参数为空值

getValue

public byte getValue()

Returns the byte value of the enumerations value

返回:

byte representation