zookeeper有哪几种节点类型
2021-08-16 本文已影响0人
Depro
- 持久节点
- 持久有序节点
- 临时节点
- 临时有序节点
public enum CreateMode {
/**
* The znode will not be automatically deleted upon client's disconnect.
*/
PERSISTENT(0, false, false, false, false),
/**
* The znode will not be automatically deleted upon client's disconnect,
* and its name will be appended with a monotonically increasing number.
*/
PERSISTENT_SEQUENTIAL(2, false, true, false, false),
/**
* The znode will be deleted upon the client's disconnect.
*/
EPHEMERAL(1, true, false, false, false),
/**
* The znode will be deleted upon the client's disconnect, and its name
* will be appended with a monotonically increasing number.
*/
EPHEMERAL_SEQUENTIAL(3, true, true, false, false),
/**
* The znode will be a container node. Container
* nodes are special purpose nodes useful for recipes such as leader, lock,
* etc. When the last child of a container is deleted, the container becomes
* a candidate to be deleted by the server at some point in the future.
* Given this property, you should be prepared to get
* {@link org.apache.zookeeper.KeeperException.NoNodeException}
* when creating children inside of this container node.
*/
CONTAINER(4, false, false, true, false),
/**
* The znode will not be automatically deleted upon client's disconnect.
* However if the znode has not been modified within the given TTL, it
* will be deleted once it has no children.
*/
PERSISTENT_WITH_TTL(5, false, false, false, true),
/**
* The znode will not be automatically deleted upon client's disconnect,
* and its name will be appended with a monotonically increasing number.
* However if the znode has not been modified within the given TTL, it
* will be deleted once it has no children.
*/
PERSISTENT_SEQUENTIAL_WITH_TTL(6, false, true, false, true);
private static final Logger LOG = LoggerFactory.getLogger(CreateMode.class);
private boolean ephemeral;
private boolean sequential;
private final boolean isContainer;
private int flag;
private boolean isTTL;
CreateMode(int flag, boolean ephemeral, boolean sequential, boolean isContainer, boolean isTTL) {
this.flag = flag;
this.ephemeral = ephemeral;
this.sequential = sequential;
this.isContainer = isContainer;
this.isTTL = isTTL;
}
public boolean isEphemeral() {
return ephemeral;
}
public boolean isSequential() {
return sequential;
}
public boolean isContainer() {
return isContainer;
}
public boolean isTTL() {
return isTTL;
}
public int toFlag() {
return flag;
}
/**
* Map an integer value to a CreateMode value
*/
public static CreateMode fromFlag(int flag) throws KeeperException {
switch (flag) {
case 0:
return CreateMode.PERSISTENT;
case 1:
return CreateMode.EPHEMERAL;
case 2:
return CreateMode.PERSISTENT_SEQUENTIAL;
case 3:
return CreateMode.EPHEMERAL_SEQUENTIAL;
case 4:
return CreateMode.CONTAINER;
case 5:
return CreateMode.PERSISTENT_WITH_TTL;
case 6:
return CreateMode.PERSISTENT_SEQUENTIAL_WITH_TTL;
default:
String errMsg = "Received an invalid flag value: " + flag + " to convert to a CreateMode";
LOG.error(errMsg);
throw new KeeperException.BadArgumentsException(errMsg);
}
}
/**
* Map an integer value to a CreateMode value
*/
public static CreateMode fromFlag(int flag, CreateMode defaultMode) {
switch (flag) {
case 0:
return CreateMode.PERSISTENT;
case 1:
return CreateMode.EPHEMERAL;
case 2:
return CreateMode.PERSISTENT_SEQUENTIAL;
case 3:
return CreateMode.EPHEMERAL_SEQUENTIAL;
case 4:
return CreateMode.CONTAINER;
case 5:
return CreateMode.PERSISTENT_WITH_TTL;
case 6:
return CreateMode.PERSISTENT_SEQUENTIAL_WITH_TTL;
default:
return defaultMode;
}
}
}