org.apache.pulsar.metadata.api

Interface MetadataStore

All Superinterfaces:

AutoCloseable

All Known Implementing Classes:

ZKMetadataStore

@Beta
public interface MetadataStore
extends AutoCloseable

Metadata store client interface. NOTE: This API is still evolving and will be refactored as needed until all the metadata usages are converted into using it.

Method Summary

Modifier and Type	Method and Description
CompletableFuture<Void>	delete(String path, Optional<Long> expectedVersion)
CompletableFuture<Boolean>	exists(String path) Read whether a specific path exists.
CompletableFuture<Optional<GetResult>>	get(String path) Read the value of one key, identified by the path The async call will return a future that yields a GetResult that will contain the value and the associated Stat object.
CompletableFuture<List<String>>	getChildren(String path) Return all the nodes (lexicographically sorted) that are children to the specific path.
CompletableFuture<Stat>	put(String path, byte[] value, Optional<Long> expectedVersion) Put a new value for a given key.

Methods inherited from interface java.lang.AutoCloseable

close

Method Detail

get

CompletableFuture<Optional<GetResult>> get(String path)

Read the value of one key, identified by the path The async call will return a future that yields a GetResult that will contain the value and the associated Stat object. If the value is not found, the future will yield an empty Optional.

Parameters:

path - the path of the key to get from the store

Returns:

a future to track the async request

getChildren

CompletableFuture<List<String>> getChildren(String path)

Return all the nodes (lexicographically sorted) that are children to the specific path. If the path itself does not exist, it will return an empty list.

Parameters:

path - webSocketProxyEnabled

Returns:

a future to track the async request

exists

CompletableFuture<Boolean> exists(String path)

Read whether a specific path exists. Note: In case of keys with multiple levels (eg: '/a/b/c'), checking the existence of a parent (eg. '/a') might not necessarily return true, unless the key had been explicitly created.

Parameters:

path - the path of the key to check on the store

Returns:

a future to track the async request

put

CompletableFuture<Stat> put(String path,
                            byte[] value,
                            Optional<Long> expectedVersion)

Put a new value for a given key. The caller can specify an expected version to be atomically checked against the current version of the stored data. The future will return the Stat object associated with the newly inserted value.

Parameters:

path - the path of the key to delete from the store

value - the value to

expectedVersion - if present, the version will have to match with the currently stored value for the operation to succeed. Use -1 to enforce a non-existing value.

Returns:

a future to track the async request

Throws:

MetadataStoreException.BadVersionException - if the expected version doesn't match the actual version of the data

delete

CompletableFuture<Void> delete(String path,
                               Optional<Long> expectedVersion)

Parameters:

path - the path of the key to delete from the store

expectedVersion - if present, the version will have to match with the currently stored value for the operation to succeed

Returns:

a future to track the async request

Throws:

MetadataStoreException.NotFoundException - if the path is not found

MetadataStoreException.BadVersionException - if the expected version doesn't match the actual version of the data