org.apache.kafka.streams.kstream.Materialized Maven / Gradle / Ivy
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* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
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* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
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* limitations under the License.
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package org.apache.kafka.streams.kstream;
import org.apache.kafka.common.serialization.Serde;
import org.apache.kafka.common.utils.Bytes;
import org.apache.kafka.streams.processor.StateStore;
import org.apache.kafka.streams.state.KeyValueBytesStoreSupplier;
import org.apache.kafka.streams.state.KeyValueStore;
import org.apache.kafka.streams.state.SessionBytesStoreSupplier;
import org.apache.kafka.streams.state.SessionStore;
import org.apache.kafka.streams.state.StoreSupplier;
import org.apache.kafka.streams.state.WindowBytesStoreSupplier;
import org.apache.kafka.streams.state.WindowStore;
import java.time.Duration;
import java.util.HashMap;
import java.util.Map;
import java.util.Objects;
import static org.apache.kafka.streams.internals.ApiUtils.prepareMillisCheckFailMsgPrefix;
import static org.apache.kafka.streams.internals.ApiUtils.validateMillisecondDuration;
/**
* Used to describe how a {@link StateStore} should be materialized.
* You can either provide a custom {@link StateStore} backend through one of the provided methods accepting a supplier
* or use the default RocksDB backends by providing just a store name.
*
* For example, you can read a topic as {@link KTable} and force a state store materialization to access the content
* via Interactive Queries API:
*
{@code
* StreamsBuilder builder = new StreamsBuilder();
* KTable table = builder.table(
* "topicName",
* Materialized.as("queryable-store-name"));
* }
*
* @param type of record key
* @param type of record value
* @param type of state store (note: state stores always have key/value types {@code }
*
* @see org.apache.kafka.streams.state.Stores
*/
public class Materialized {
protected StoreSupplier storeSupplier;
protected String storeName;
protected Serde valueSerde;
protected Serde keySerde;
protected boolean loggingEnabled = true;
protected boolean cachingEnabled = true;
protected Map topicConfig = new HashMap<>();
protected Duration retention;
public StoreType storeType;
// the built-in state store types
public enum StoreType {
ROCKS_DB,
IN_MEMORY
}
private Materialized(final StoreSupplier storeSupplier) {
this.storeSupplier = storeSupplier;
}
private Materialized(final String storeName) {
this.storeName = storeName;
}
private Materialized(final StoreType storeType) {
this.storeType = storeType;
}
/**
* Copy constructor.
* @param materialized the {@link Materialized} instance to copy.
*/
protected Materialized(final Materialized materialized) {
this.storeSupplier = materialized.storeSupplier;
this.storeName = materialized.storeName;
this.keySerde = materialized.keySerde;
this.valueSerde = materialized.valueSerde;
this.loggingEnabled = materialized.loggingEnabled;
this.cachingEnabled = materialized.cachingEnabled;
this.topicConfig = materialized.topicConfig;
this.retention = materialized.retention;
this.storeType = materialized.storeType;
}
/**
* Materialize a {@link StateStore} with the given {@link StoreType}.
*
* @param storeType the type of the state store
* @param key type of the store
* @param value type of the store
* @param type of the {@link StateStore}
* @return a new {@link Materialized} instance with the given storeName
*/
public static Materialized as(final StoreType storeType) {
Objects.requireNonNull(storeType, "store type can't be null");
return new Materialized<>(storeType);
}
/**
* Materialize a {@link StateStore} with the given name.
*
* @param storeName the name of the underlying {@link KTable} state store; valid characters are ASCII
* alphanumerics, '.', '_' and '-'.
* @param key type of the store
* @param value type of the store
* @param type of the {@link StateStore}
* @return a new {@link Materialized} instance with the given storeName
*/
public static Materialized as(final String storeName) {
Named.validate(storeName);
return new Materialized<>(storeName);
}
/**
* Materialize a {@link WindowStore} using the provided {@link WindowBytesStoreSupplier}.
*
* Important: Custom subclasses are allowed here, but they should respect the retention contract:
* Window stores are required to retain windows at least as long as (window size + window grace period).
* Stores constructed via {@link org.apache.kafka.streams.state.Stores} already satisfy this contract.
*
* @param supplier the {@link WindowBytesStoreSupplier} used to materialize the store
* @param key type of the store
* @param value type of the store
* @return a new {@link Materialized} instance with the given supplier
*/
public static Materialized> as(final WindowBytesStoreSupplier supplier) {
Objects.requireNonNull(supplier, "supplier can't be null");
return new Materialized<>(supplier);
}
/**
* Materialize a {@link SessionStore} using the provided {@link SessionBytesStoreSupplier}.
*
* Important: Custom subclasses are allowed here, but they should respect the retention contract:
* Session stores are required to retain windows at least as long as (session inactivity gap + session grace period).
* Stores constructed via {@link org.apache.kafka.streams.state.Stores} already satisfy this contract.
*
* @param supplier the {@link SessionBytesStoreSupplier} used to materialize the store
* @param key type of the store
* @param value type of the store
* @return a new {@link Materialized} instance with the given sup
* plier
*/
public static Materialized> as(final SessionBytesStoreSupplier supplier) {
Objects.requireNonNull(supplier, "supplier can't be null");
return new Materialized<>(supplier);
}
/**
* Materialize a {@link KeyValueStore} using the provided {@link KeyValueBytesStoreSupplier}.
*
* @param supplier the {@link KeyValueBytesStoreSupplier} used to materialize the store
* @param key type of the store
* @param value type of the store
* @return a new {@link Materialized} instance with the given supplier
*/
public static Materialized> as(final KeyValueBytesStoreSupplier supplier) {
Objects.requireNonNull(supplier, "supplier can't be null");
return new Materialized<>(supplier);
}
/**
* Materialize a {@link StateStore} with the provided key and value {@link Serde}s.
* An internal name will be used for the store.
*
* @param keySerde the key {@link Serde} to use. If the {@link Serde} is null, then the default key
* serde from configs will be used
* @param valueSerde the value {@link Serde} to use. If the {@link Serde} is null, then the default value
* serde from configs will be used
* @param key type
* @param value type
* @param store type
* @return a new {@link Materialized} instance with the given key and value serdes
*/
public static Materialized with(final Serde keySerde,
final Serde valueSerde) {
return new Materialized((String) null).withKeySerde(keySerde).withValueSerde(valueSerde);
}
/**
* Set the valueSerde the materialized {@link StateStore} will use.
*
* @param valueSerde the value {@link Serde} to use. If the {@link Serde} is null, then the default value
* serde from configs will be used. If the serialized bytes is null for put operations,
* it is treated as delete operation
* @return itself
*/
public Materialized withValueSerde(final Serde valueSerde) {
this.valueSerde = valueSerde;
return this;
}
/**
* Set the keySerde the materialize {@link StateStore} will use.
* @param keySerde the key {@link Serde} to use. If the {@link Serde} is null, then the default key
* serde from configs will be used
* @return itself
*/
public Materialized withKeySerde(final Serde keySerde) {
this.keySerde = keySerde;
return this;
}
/**
* Indicates that a changelog should be created for the store. The changelog will be created
* with the provided configs.
*
* Note: Any unrecognized configs will be ignored.
* @param config any configs that should be applied to the changelog
* @return itself
*/
public Materialized withLoggingEnabled(final Map config) {
loggingEnabled = true;
this.topicConfig = config;
return this;
}
/**
* Disable change logging for the materialized {@link StateStore}.
* @return itself
*/
public Materialized withLoggingDisabled() {
loggingEnabled = false;
this.topicConfig.clear();
return this;
}
/**
* Enable caching for the materialized {@link StateStore}.
* @return itself
*/
public Materialized withCachingEnabled() {
cachingEnabled = true;
return this;
}
/**
* Disable caching for the materialized {@link StateStore}.
* @return itself
*/
public Materialized withCachingDisabled() {
cachingEnabled = false;
return this;
}
/**
* Configure retention period for window and session stores. Ignored for key/value stores.
*
* Overridden by pre-configured store suppliers
* ({@link Materialized#as(SessionBytesStoreSupplier)} or {@link Materialized#as(WindowBytesStoreSupplier)}).
*
* Note that the retention period must be at least long enough to contain the windowed data's entire life cycle,
* from window-start through window-end, and for the entire grace period. If not specified, the retention
* period would be set as the window length (from window-start through window-end) plus the grace period.
*
* @param retention the retention time
* @return itself
* @throws IllegalArgumentException if retention is negative or can't be represented as {@code long milliseconds}
*/
public Materialized withRetention(final Duration retention) throws IllegalArgumentException {
final String msgPrefix = prepareMillisCheckFailMsgPrefix(retention, "retention");
final long retentionMs = validateMillisecondDuration(retention, msgPrefix);
if (retentionMs < 0) {
throw new IllegalArgumentException("Retention must not be negative.");
}
this.retention = retention;
return this;
}
/**
* Set the type of the materialized {@link StateStore}.
*
* @param storeType the store type {@link StoreType} to use.
* @return itself
* @throws IllegalArgumentException if store supplier is also pre-configured
*/
public Materialized withStoreType(final StoreType storeType) throws IllegalArgumentException {
Objects.requireNonNull(storeType, "store type can't be null");
if (storeSupplier != null) {
throw new IllegalArgumentException("Cannot set store type when store supplier is pre-configured.");
}
this.storeType = storeType;
return this;
}
}