org.apache.flink.table.runtime.functions.table.lookup

类 CachingLookupFunction

java.lang.Object

org.apache.flink.table.functions.UserDefinedFunction

org.apache.flink.table.functions.TableFunction<org.apache.flink.table.data.RowData>

org.apache.flink.table.functions.LookupFunction

org.apache.flink.table.runtime.functions.table.lookup.CachingLookupFunction

所有已实现的接口:

Serializable, org.apache.flink.table.functions.FunctionDefinition

@Internal
public class CachingLookupFunction
extends org.apache.flink.table.functions.LookupFunction

A wrapper function around user-provided lookup function with a cache layer.

This function will check the cache on lookup request and return entries directly on cache hit, otherwise the function will invoke the actual lookup function, and store the entry into the cache after lookup for later use.

另请参阅:

序列化表格

字段概要

字段

限定符和类型	字段和说明
static String	LOOKUP_CACHE_METRIC_GROUP_NAME

构造器概要

构造器

构造器和说明
CachingLookupFunction(org.apache.flink.table.connector.source.lookup.cache.LookupCache cache, org.apache.flink.table.functions.LookupFunction delegate) Create a CachingLookupFunction.

方法概要

限定符和类型	方法和说明
void	close()
org.apache.flink.table.connector.source.lookup.cache.LookupCache	getCache()
Collection<org.apache.flink.table.data.RowData>	lookup(org.apache.flink.table.data.RowData keyRow)
void	open(org.apache.flink.table.functions.FunctionContext context) Open the CachingLookupFunction.

从类继承的方法 org.apache.flink.table.functions.LookupFunction

eval

从类继承的方法 org.apache.flink.table.functions.TableFunction

collect, finish, getKind, getParameterTypes, getResultType, getTypeInference, setCollector

从类继承的方法 org.apache.flink.table.functions.UserDefinedFunction

functionIdentifier, toString

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

从接口继承的方法 org.apache.flink.table.functions.FunctionDefinition

getRequirements, isDeterministic, supportsConstantFolding

字段详细资料

LOOKUP_CACHE_METRIC_GROUP_NAME

public static final String LOOKUP_CACHE_METRIC_GROUP_NAME

另请参阅:

常量字段值

构造器详细资料

CachingLookupFunction

public CachingLookupFunction(org.apache.flink.table.connector.source.lookup.cache.LookupCache cache,
                             @Nullable
                             org.apache.flink.table.functions.LookupFunction delegate)

Create a CachingLookupFunction.

Please note that the cache may not be the final instance serving in this function. The actual cache instance will be retrieved from the LookupCacheManager during open(org.apache.flink.table.functions.FunctionContext).

方法详细资料

open

public void open(org.apache.flink.table.functions.FunctionContext context)
          throws Exception

Open the CachingLookupFunction.

In order to reduce the memory usage of the cache, LookupCacheManager is used to provide a shared cache instance across subtasks of this function. Here we use UserDefinedFunction.functionIdentifier() as the id of the cache, which is generated by MD5 of serialized bytes of this function. As different subtasks of the function will generate the same MD5, this could promise that they will be served with the same cache instance.

覆盖:

open 在类中 org.apache.flink.table.functions.UserDefinedFunction

抛出:

Exception

另请参阅:

UserDefinedFunction.functionIdentifier()

lookup

public Collection<org.apache.flink.table.data.RowData> lookup(org.apache.flink.table.data.RowData keyRow)
                                                       throws IOException

指定者:

lookup 在类中 org.apache.flink.table.functions.LookupFunction

抛出:

IOException

close

public void close()
           throws Exception

覆盖:

close 在类中 org.apache.flink.table.functions.UserDefinedFunction

抛出:

Exception

getCache

@VisibleForTesting
public org.apache.flink.table.connector.source.lookup.cache.LookupCache getCache()