14 March 2024

Data Type Metadata

GigaSpaces provides the ability to obtain and modify class metadata of objects stored in the Space during runtime.

Metadata Discovery

The actual class names are discovered with the Admin interface through the Space interface.

import org.openspaces.admin.AdminFactory;
import org.openspaces.admin.space.Space;
...

Admin admin = new AdminFactory().discoverUnmanagedSpaces().addGroup("TEST").createAdmin();
...
Space space = admin.getSpaces().waitFor(spaceName  , 10 , TimeUnit.SECONDS);
....
String SpaceClassNames[] = space.getRuntimeDetails().getClassNames();
...

The GigaSpaceTypeManager is retrieved from the Space instance and will give us the detailed information for each class:

GigaSpace gigaSpace = new GigaSpaceConfigurer(new SpaceProxyConfigurer(spaceName).lookupGroups("TEST")).gigaSpace();
....
GigaSpaceTypeManager gigaSpaceTypeManager = gigaSpace.getTypeManager();

We can iterate over all classes that are present in the Space and obtain their metadata:

for (int j = 0; j < SpaceClassNames.length; j++) {
    String spaceClass = SpaceClassNames[j];

    SpaceTypeDescriptor typeManager = gigaSpaceTypeManager.getTypeDescriptor(spaceClass);
    System.out.println("Super Type Name:" + typeManager.getSuperTypeName());
    System.out.println("Id Property Name:"+ typeManager.getIdPropertyName());   
    .......
}

Example

Lets assume that we have an abstract super class Entity and two sub-classes, Bank and Supplier.

import java.util.UUID;

import com.gigaspaces.annotation.pojo.SpaceId;

public abstract class Entity {
    private UUID id;
    private String emailAddress;
    private String contact;

    @SpaceId(autoGenerate=false)
    public UUID getId() {
        return id;
    }
    public void setId(UUID id) {
        this.id = id;
    }
    public String getEmailAddress() {
        return emailAddress;
    }
    public void setEmailAddress(String emailAddress) {
        this.emailAddress = emailAddress;
    }
    public String getContact() {
        return contact;
    }
    public void setContact(String contact) {
        this.contact = contact;
    }
}

import com.gigaspaces.annotation.pojo.SpaceClass;
import com.gigaspaces.annotation.pojo.SpaceIndex;

@SpaceClass
public class Bank extends Entity {
    private String swift;
    private String iban;
    private Collection<String> currencyRates;

    @SpaceIndex
    public String getSwift() {
        return swift;
    }
    public void setSwift(String swift) {
        this.swift = swift;
    }
    public String getIban() {
        return iban;
    }
    public void setIban(String iban) {
        this.iban = iban;
    }
    public Collection<String> getCurrencyRates() {
        return currencyRates;
    }
    public void setCurrencyRates(Collection<String> currencyRates) {
        this.currencyRates = currencyRates;
    }
}

import com.gigaspaces.annotation.pojo.SpaceClass;

@SpaceClass
public class Supplier extends Entity {
    private Integer number;
    private ESupplierType category;

    public Integer getNumber() {
        return number;
    }
    public void setNumber(Integer number) {
        this.number = number;
    }
    public ESupplierType getCategory() {
        return category;
    }
    public void setCategory(ESupplierType category) {
        this.category = category;
    }
}

public enum ESupplierType {
    NATIONAL, INTERNATIONAL
}

Here is an example that uses the GigaSpaceTypeManager to explore the Space for metadata:

@Test
public void test() throws InterruptedException {
    String spaceName = "mySpace";

    GigaSpace gigaSpaceEmb = new GigaSpaceConfigurer(new EmbeddedSpaceConfigurer(spaceName).lookupGroups("TEST"))
                .gigaSpace();

    System.out.println(
            "This test will write 2 space objects into the space , each using different classes and will use the SpaceTypeDescriptor to retrieve the space class meta data back");

    // wait for the admin to synchronize
    Thread.sleep(1000);
    Admin admin = new AdminFactory().discoverUnmanagedSpaces().addGroup("TEST").createAdmin();

    if (admin == null) {
        System.out.println("Can't find space " + spaceName + " Exit!");
        System.exit(0);
    }

    Space space = admin.getSpaces().waitFor(spaceName, 20, TimeUnit.SECONDS);

    if (space == null) {
        System.out.println("Can't find space " + spaceName + " Exit!");
        System.exit(0);
    }

    GigaSpace gigaSpace = new GigaSpaceConfigurer(new SpaceProxyConfigurer(spaceName).lookupGroups("TEST"))
                .gigaSpace();

    // Create two new objects and write them to the Space
    Bank b = new Bank();
    b.setId(UUID.randomUUID());
    gigaSpace.write(b);
    Supplier s = new Supplier();
    s.setId(UUID.randomUUID());
    gigaSpace.write(s);

    String SpaceClassNames[] = space.getRuntimeDetails().getClassNames();
    GigaSpaceTypeManager gigaSpaceTypeManager = gigaSpace.getTypeManager();

    // Explore the space classes
    for (int j = 0; j < SpaceClassNames.length; j++) {
        String spaceClass = SpaceClassNames[j];
        System.out.println();
        System.out.println("Meta Data       :" + spaceClass);
        SpaceTypeDescriptor typeManager = gigaSpaceTypeManager.getTypeDescriptor(spaceClass);
        System.out.println("Super Type Name :" + typeManager.getSuperTypeName());
        System.out.println("Id Property Name:" + typeManager.getIdPropertyName());
        System.out.println("Indexes         :" + typeManager.getIndexes());
        String[] typeNames = typeManager.getPropertiesNames();
        System.out.println("Properties:");
        for (int i = 0; i < typeNames.length; i++) {
            String prop = typeNames[i];
            SpacePropertyDescriptor propdesc = typeManager.getFixedProperty(prop);

            System.out.println("  Name:" + propdesc.getName() + " Type:" + propdesc.getTypeName() + " Storage Type:"
                        + propdesc.getStorageType());
        }
    }
    admin.close();

    System.exit(0);
}

The above program will produce the following output when executed:

This test will write 2 space objects into the space , each using different classes and will use the SpaceTypeDescriptor to retrieve the space class meta data back

Meta Data       :java.lang.Object
Super Type Name :java.lang.Object
Id Property Name:null
Indexes         :{}
Properties:

Meta Data       :xap.sandbox.type.Bank
Super Type Name :xap.sandbox.type.Entity
Id Property Name:id
Indexes         :{id=SpaceIndex[name=id, type=EQUAL, unique=true], swift=SpaceIndex[name=swift, type=EQUAL, unique=false]}
Properties:
  Name:contact Type:java.lang.String Storage Type:OBJECT
  Name:emailAddress Type:java.lang.String Storage Type:OBJECT
  Name:id Type:java.util.UUID Storage Type:OBJECT
  Name:currencyRates Type:java.util.Collection Storage Type:OBJECT
  Name:iban Type:java.lang.String Storage Type:OBJECT
  Name:swift Type:java.lang.String Storage Type:OBJECT

Meta Data       :xap.sandbox.type.Entity
Super Type Name :java.lang.Object
Id Property Name:id
Indexes         :{id=SpaceIndex[name=id, type=EQUAL, unique=true]}
Properties:
  Name:contact Type:java.lang.String Storage Type:OBJECT
  Name:emailAddress Type:java.lang.String Storage Type:OBJECT
  Name:id Type:java.util.UUID Storage Type:OBJECT

Meta Data       :xap.sandbox.type.Supplier
Super Type Name :xap.sandbox.type.Entity
Id Property Name:id
Indexes         :{id=SpaceIndex[name=id, type=EQUAL, unique=true]}
Properties:
  Name:contact Type:java.lang.String Storage Type:OBJECT
  Name:emailAddress Type:java.lang.String Storage Type:OBJECT
  Name:id Type:java.util.UUID Storage Type:OBJECT
  Name:category Type:xap.sandbox.type.ESupplierType Storage Type:OBJECT
  Name:number Type:java.lang.Integer Storage Type:OBJECT

All information per class (super, sub and embedded class), properties, indexes, IDs etc. is displayed.

Modifying Existing Classes

It is possible to modify existing classes in the Space. For example, we can add indexes during runtime.

Lets take our example Bank, we want to add an additional index for the columns iban :

AsyncFuture<AddTypeIndexesResult> asyncAddIndex = gigaSpace.getTypeManager().asyncAddIndex("xap.sandbox.type.Bank",
                   SpaceIndexFactory.createPropertyIndex("iban", SpaceIndexType.EQUAL));

Meta Data :xap.sandbox.type.Bank
Super Type Name :xap.sandbox.type.Entity
Id Property Name:id
Indexes :{id=SpaceIndex[name=id, type=EQUAL, unique=true], swift=SpaceIndex[name=swift, type=EQUAL, unique=false], iban=SpaceIndex[name=iban, type=EQUAL, unique=false]}
Properties:
 Name:contact Type:java.lang.String Storage Type:OBJECT
 Name:emailAddress Type:java.lang.String Storage Type:OBJECT
 Name:id Type:java.util.UUID Storage Type:OBJECT
 Name:currencyRates Type:java.util.Collection Storage Type:OBJECT
 Name:iban Type:java.lang.String Storage Type:OBJECT
 Name:swift Type:java.lang.String Storage Type:OBJECT

It is also possible to add a CompoundIndex. Lets take our Supplier class, we want to add a compound index for the columns number and category :

AsyncFuture<AddTypeIndexesResult> indexesResultAsyncFuture = gigaSpace.getTypeManager()
            .asyncAddIndex("xap.sandbox.type.Supplier", new CompoundIndex(new String[] { "number", "category" }));

Meta Data :xap.sandbox.type.Supplier
Super Type Name :xap.sandbox.type.Entity
Id Property Name:id
Indexes :{number+category=SpaceIndex[name=number+category, type=EQUAL, unique=false], id=SpaceIndex[name=id, type=EQUAL, unique=true]}
Properties:
 Name:contact Type:java.lang.String Storage Type:OBJECT
 Name:emailAddress Type:java.lang.String Storage Type:OBJECT
 Name:id Type:java.util.UUID Storage Type:OBJECT
 Name:category Type:xap.sandbox.type.ESupplierType Storage Type:OBJECT
 Name:number Type:java.lang.Integer Storage Type:OBJECT

Adding Space Document

New SpaceDocuments can be introduced during runtime:

// Create type descriptor:
SpaceTypeDescriptor typeDescriptor = new SpaceTypeDescriptorBuilder("Product")
        .addPropertyIndex("name", SpaceIndexType.EQUAL)
// ... Other type settings
        .documentWrapperClass(Document.class).create();

gigaSpace.getTypeManager().registerTypeDescriptor(typeDescriptor);

Meta Data :Product
Super Type Name :java.lang.Object
Id Property Name:_spaceId
Indexes :{name=SpaceIndex[name=name, type=EQUAL, unique=false]}
Document Wrapper :class xap.sandbox.type.Document
Properties:
 Name:_spaceId Type:java.lang.Object Storage Type:OBJECT

Meta Data :java.lang.Object
Super Type Name :java.lang.Object
Id Property Name:null
Indexes :{}
Document Wrapper :class com.gigaspaces.document.SpaceDocument
Properties: