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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more 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
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.pulsar.client.api;

import static org.apache.pulsar.client.internal.PulsarClientImplementationBinding.getBytes;
import java.nio.ByteBuffer;
import java.sql.Time;
import java.sql.Timestamp;
import java.time.Instant;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.util.Date;
import java.util.Optional;
import org.apache.pulsar.client.api.schema.GenericObject;
import org.apache.pulsar.client.api.schema.GenericRecord;
import org.apache.pulsar.client.api.schema.GenericSchema;
import org.apache.pulsar.client.api.schema.SchemaDefinition;
import org.apache.pulsar.client.api.schema.SchemaInfoProvider;
import org.apache.pulsar.client.internal.DefaultImplementation;
import org.apache.pulsar.common.classification.InterfaceAudience;
import org.apache.pulsar.common.classification.InterfaceStability;
import org.apache.pulsar.common.schema.KeyValue;
import org.apache.pulsar.common.schema.KeyValueEncodingType;
import org.apache.pulsar.common.schema.SchemaInfo;
import org.apache.pulsar.common.schema.SchemaType;

/**
 * Message schema definition.
 */
@InterfaceAudience.Public
@InterfaceStability.Stable
public interface Schema extends Cloneable {

    /**
     * Check if the message is a valid object for this schema.
     *
     * 

The implementation can choose what its most efficient approach to validate the schema. * If the implementation doesn't provide it, it will attempt to use {@link #decode(byte[])} * to see if this schema can decode this message or not as a validation mechanism to verify * the bytes. * * @param message the messages to verify * @throws SchemaSerializationException if it is not a valid message */ default void validate(byte[] message) { decode(message); } /** * Encode an object representing the message content into a byte array. * * @param message * the message object * @return a byte array with the serialized content * @throws SchemaSerializationException * if the serialization fails */ byte[] encode(T message); /** * Returns whether this schema supports versioning. * *

Most of the schema implementations don't really support schema versioning, or it just doesn't * make any sense to support schema versionings (e.g. primitive schemas). Only schema returns * {@link GenericRecord} should support schema versioning. * *

If a schema implementation returns false, it should implement {@link #decode(byte[])}; * while a schema implementation returns true, it should implement {@link #decode(byte[], byte[])} * instead. * * @return true if this schema implementation supports schema versioning; otherwise returns false. */ default boolean supportSchemaVersioning() { return false; } default void setSchemaInfoProvider(SchemaInfoProvider schemaInfoProvider) { } /** * Decode a byte array into an object using the schema definition and deserializer implementation. * * @param bytes * the byte array to decode * @return the deserialized object */ default T decode(byte[] bytes) { // use `null` to indicate ignoring schema version return decode(bytes, null); } /** * Decode a byte array into an object using a given version. * * @param bytes * the byte array to decode * @param schemaVersion * the schema version to decode the object. null indicates using latest version. * @return the deserialized object */ default T decode(byte[] bytes, byte[] schemaVersion) { // ignore version by default (most of the primitive schema implementations ignore schema version) return decode(bytes); } /** * Decode a ByteBuffer into an object using a given version.
* * @param data * the ByteBuffer to decode * @return the deserialized object */ default T decode(ByteBuffer data) { if (data == null) { return null; } return decode(getBytes(data)); } /** * Decode a ByteBuffer into an object using a given version.
* * @param data * the ByteBuffer to decode * @param schemaVersion * the schema version to decode the object. null indicates using latest version. * @return the deserialized object */ default T decode(ByteBuffer data, byte[] schemaVersion) { if (data == null) { return null; } return decode(getBytes(data), schemaVersion); } /** * @return an object that represents the Schema associated metadata */ SchemaInfo getSchemaInfo(); /** * Check if this schema requires fetching schema info to configure the schema. * * @return true if the schema requires fetching schema info to configure the schema, * otherwise false. */ default boolean requireFetchingSchemaInfo() { return false; } /** * Configure the schema to use the provided schema info. * * @param topic topic name * @param componentName component name * @param schemaInfo schema info */ default void configureSchemaInfo(String topic, String componentName, SchemaInfo schemaInfo) { // no-op } /** * Duplicates the schema. * * @return The duplicated schema. */ Schema clone(); /** * Schema that doesn't perform any encoding on the message payloads. Accepts a byte array and it passes it through. */ Schema BYTES = DefaultImplementation.getDefaultImplementation().newBytesSchema(); /** * Return the native schema that is wrapped by Pulsar API. * For instance with this method you can access the Avro schema * @return the internal schema or null if not present */ default Optional getNativeSchema() { return Optional.empty(); } /** * ByteBuffer Schema. */ Schema BYTEBUFFER = DefaultImplementation.getDefaultImplementation().newByteBufferSchema(); /** * Schema that can be used to encode/decode messages whose values are String. The payload is encoded with UTF-8. */ Schema STRING = DefaultImplementation.getDefaultImplementation().newStringSchema(); /** * INT8 Schema. */ Schema INT8 = DefaultImplementation.getDefaultImplementation().newByteSchema(); /** * INT16 Schema. */ Schema INT16 = DefaultImplementation.getDefaultImplementation().newShortSchema(); /** * INT32 Schema. */ Schema INT32 = DefaultImplementation.getDefaultImplementation().newIntSchema(); /** * INT64 Schema. */ Schema INT64 = DefaultImplementation.getDefaultImplementation().newLongSchema(); /** * Boolean Schema. */ Schema BOOL = DefaultImplementation.getDefaultImplementation().newBooleanSchema(); /** * Float Schema. */ Schema FLOAT = DefaultImplementation.getDefaultImplementation().newFloatSchema(); /** * Double Schema. */ Schema DOUBLE = DefaultImplementation.getDefaultImplementation().newDoubleSchema(); /** * Date Schema. */ Schema DATE = DefaultImplementation.getDefaultImplementation().newDateSchema(); /** * Time Schema. */ Schema