Chapter 23. Remote Querying

.library.proto

package book_sample;
message Book {
    required string title = 1;
    required string description = 2;
    required int32 publicationYear = 3; // no native Date type available in Protobuf

    repeated Author authors = 4;
}
message Author {
    required string name = 1;
    required string surname = 2;
}

Use the ProtoStreamMarshaller to Encode and Marshall Messages

import org.infinispan.client.hotrod.configuration.ConfigurationBuilder;
import org.infinispan.client.hotrod.marshall.ProtoStreamMarshaller;
import org.infinispan.protostream.FileDescriptorSource;
import org.infinispan.protostream.SerializationContext;
...
ConfigurationBuilder clientBuilder = new ConfigurationBuilder();
clientBuilder.addServer()
    .host("127.0.0.1").port(11234)
    .marshaller(new ProtoStreamMarshaller());

RemoteCacheManager remoteCacheManager = new RemoteCacheManager(clientBuilder.build());
SerializationContext serCtx =
    ProtoStreamMarshaller.getSerializationContext(remoteCacheManager);
serCtx.registerProtoFiles(FileDescriptorSource.fromResources("/library.proto"));
serCtx.registerMarshaller(new BookMarshaller());
serCtx.registerMarshaller(new AuthorMarshaller());
// Book and Author classes omitted for brevity

BookMarshaller.java

import org.infinispan.protostream.MessageMarshaller;
...
public class BookMarshaller implements MessageMarshaller<Book> {
    @Override
    public String getTypeName() {
        return "book_sample.Book";
    }
    @Override
    public Class<? extends Book> getJavaClass() {
        return Book.class;
    }
    @Override
    public void writeTo(ProtoStreamWriter writer, Book book) throws IOException {
        writer.writeString("title", book.getTitle());
        writer.writeString("description", book.getDescription());
        writer.writeCollection("authors", book.getAuthors(), Author.class);
    }
    @Override
    public Book readFrom(ProtoStreamReader reader) throws IOException {
        String title = reader.readString("title");
        String description = reader.readString("description");
        int publicationYear = reader.readInt("publicationYear");
        Set<Author> authors = reader.readCollection("authors",
            new HashSet<Author>(), Author.class);
        return new Book(title, description, publicationYear, authors);
    }
}

Registering a Protocol Buffers schema file

import org.infinispan.client.hotrod.RemoteCache;
import org.infinispan.client.hotrod.RemoteCacheManager;
import org.infinispan.query.remote.client.ProtobufMetadataManagerConstants;

RemoteCacheManager remoteCacheManager = ... // obtain a RemoteCacheManager

// obtain the '__protobuf_metadata' cache
RemoteCache<String, String> metadataCache =
    remoteCacheManager.getCache(
        ProtobufMetadataManagerConstants.PROTOBUF_METADATA_CACHE_NAME);

String schemaFileContents = ... // this is the contents of the schema file
metadataCache.put("my_protobuf_schema.proto", schemaFileContents);

User.Java

package sample;

import org.infinispan.protostream.annotations.ProtoEnum;
import org.infinispan.protostream.annotations.ProtoEnumValue;
import org.infinispan.protostream.annotations.ProtoField;
import org.infinispan.protostream.annotations.ProtoMessage;

@ProtoMessage(name = "ApplicationUser")
public class User {

    @ProtoEnum(name = "Gender")
    public enum Gender {
        @ProtoEnumValue(number = 1, name = "M")
        MALE,

        @ProtoEnumValue(number = 2, name = "F")
        FEMALE
    }

    @ProtoField(number = 1, required = true)
    public String name;

    @ProtoField(number = 2)
    public Gender gender;
}

Note.Java

package sample;

import org.infinispan.protostream.annotations.ProtoDoc;
import org.infinispan.protostream.annotations.ProtoField;

@ProtoDoc("@Indexed")
public class Note {

    private String text;

    private User author;

    @ProtoDoc("@Field")
    @ProtoField(number = 1)
    public String getText() {
        return text;
    }

    public void setText(String text) {
        this.text = text;
    }

    @ProtoDoc("@Field(store = Store.YES)")
    @ProtoField(number = 2)
    public User getAuthor() {
        return author;
    }

    public void setAuthor(User author) {
        this.author = author;
    }
}

ProtoSchemaBuilderDemo.Java

import org.infinispan.protostream.SerializationContext;
import org.infinispan.protostream.annotations.ProtoSchemaBuilder;
import org.infinispan.client.hotrod.RemoteCacheManager;
import org.infinispan.client.hotrod.marshall.ProtoStreamMarshaller;

...

RemoteCacheManager remoteCacheManager = ... // we have a RemoteCacheManager
SerializationContext serCtx =
    ProtoStreamMarshaller.getSerializationContext(remoteCacheManager);

// generate and register a Protobuf schema and marshallers based
// on Note class and the referenced classes (User class)
ProtoSchemaBuilder protoSchemaBuilder = new ProtoSchemaBuilder();
String generatedSchema = protoSchemaBuilder
    .fileName("sample_schema.proto")
    .packageName("sample_package")
    .addClass(Note.class)
    .build(serCtx);

// the types can be marshalled now
assertTrue(serCtx.canMarshall(User.class));
assertTrue(serCtx.canMarshall(Note.class));
assertTrue(serCtx.canMarshall(User.Gender.class));

// display the schema file
System.out.println(generatedSchema);

Sample_Schema.Proto

package sample_package;

 /* @Indexed */
message Note {

   /* @Field */
   optional string text = 1;

   /* @Field(store = Store.YES) */
   optional ApplicationUser author = 2;
}

message ApplicationUser {

   enum Gender {
      M = 1;
      F = 2;
   }

   required string name = 1;
   optional Gender gender = 2;
}