org.apache.storm.metricstore.rocksdb

Interface WritableStringMetadataCache

All Superinterfaces:

ReadOnlyStringMetadataCache

All Known Implementing Classes:

StringMetadataCache

public interface WritableStringMetadataCache
extends ReadOnlyStringMetadataCache

The writable interface to a StringMetadataCache intended to be used by a single RocksDBMetricwWriter instance. This class is not thread safe.

Method Summary

Modifier and Type	Method and Description
Set<Map.Entry<String,org.apache.storm.metricstore.rocksdb.StringMetadata>>	entrySet() Get the map of the cache contents.
void	put(String s, org.apache.storm.metricstore.rocksdb.StringMetadata stringMetadata, boolean newEntry) Add the string metadata to the cache.

Methods inherited from interface org.apache.storm.metricstore.rocksdb.ReadOnlyStringMetadataCache

contains, get, getMetadataString

Method Detail

put

void put(String s,
         org.apache.storm.metricstore.rocksdb.StringMetadata stringMetadata,
         boolean newEntry)
  throws MetricException

Add the string metadata to the cache.

• NOTE: this can cause data to be evicted from the cache when full. When this occurs, the evictionCallback() method is called to store the metadata back into the RocksDB database.

This method is only exposed to the WritableStringMetadataCache interface.

Parameters:

s - The string to add

stringMetadata - The string’s metadata

newEntry - Indicates the metadata is being used for the first time and should be written to RocksDB immediately

Throws:

MetricException - when evicted data fails to save to the database or when the database is shutdown

entrySet

Set<Map.Entry<String,org.apache.storm.metricstore.rocksdb.StringMetadata>> entrySet()

Get the map of the cache contents. Provided to allow writing the data to RocksDB on shutdown.

Returns:

the string metadata map entrySet