Configure Searchable Attributes for Data Structures in Cache

A data structure can also be associated with the searchable attributes such as:

These searchable attributes can be used to query all associated items, as explained in Querying Data Structures. For example, a CacheItem and HashSet can belong to the same group. These attributes are specified using the DataTypeAttributes class.

Important

These attributes can not be modified once a data structure is created. However, the data structure itself can be modified.

Prerequisites

To learn about the standard prerequisites required to work with all NCache client-side features, please refer to the given page on Client-Side API Prerequisites.
For API details, refer to: ICache, DataTypeAttributes, NamedTagsDictionary, Tag, Group, NamedTags, IDistributedHashSet, DataTypeManager, CreateHashSet, Contains, Count.

The following code sample creates a HashSet ProductIDSet of int type and specifies Group Electronics, Tags and a Named Tag to it using DataTypeAttributes. The ProductIDs are then fetched and added to this HashSet. You can also query on these set values.

Tip

One quick way to verify whether a data structure has been created is to use either properties of the Cache class:

Count returns the number of items present in the cache.
Contains verifies if the specified key of the data structure exists in the cache.

// Precondition: Cache must be connected

// Specify unique cache key for set
string key = "ProductIDSet";

// Specify attributes for HashSet
var attributes = new DataTypeAttributes();

// Specify group "Electronics"
attributes.Group = "Electronics";

// Specify tags
Tag[] tags = new Tag[2];
tags[0] = new Tag("2 Year Warranty");
tags[1] = new Tag("Stainless Steel");
attributes.Tags = tags;

// Specify Named Tag
var namedTag = new NamedTagsDictionary();
namedTag.Add("Discount", 0.4);
attributes.NamedTags = namedTag;

// Create HashSet with attributes
IDistributedHashSet<int> hashSet = cache.DataTypeManager.CreateHashSet<int>(key, attributes);

// Adding Product IDs to HashSet
int[] productIDs = FetchProductIDs();
foreach(var productID in productIDs)
{
    // Add product IDs to HashSet
    hashSet.Add(productID);
}
// You can also query on this HashSet using these attributes

// Precondition: Cache must be connected

// Specify unique cache key for set
String key = "ProductIDSet";

// Specify attributes for HashSet
var attributes = new DataStructureAttributes();

// Specify group "Electronics"
attributes.setGroup("Electronics");

// Specify tags
Tag[] tags = new Tag[2];
tags[0] = new Tag("2 Year Warranty");
tags[1] = new Tag("Stainless Steel");
attributes.setTags(Arrays.asList(tags));

// Specify Named Tag
var namedTag = new NamedTagsDictionary();
namedTag.add("Discount", 0.4);
attributes.setNamedTags(namedTag);
var writeThruOptions = null;

// Create HashSet with attributes
DistributedHashSet hashSet = cache.getDataStructuresManager().createHashSet(key, attributes, writeThruOptions, Integer.class);

// Adding Product IDs to HashSet
int[] productIDs = fetchProductIDs();
for (var productID : productIDs) {
    // Add product IDs to HashSet
    hashSet.add(productID);
}
// You can query on this HashSet using these attributes

// This is an async method
// Pre-condition: Cache must be connected

// Specify unique cache key for HashSet
var key = "ProductIDSet";

// Specify attributes for HashSet
var attributes = new ncache.DataStructureAttributes();

// Specify group "Electronics"
attributes.setGroup("Electronics");

// Specify tags
var tags = [
new ncache.Tag("2 Year Warranty"),
new ncache.Tag("Stainless Steel"),
];
attributes.setTags(tag);

// Specify Named Tag
var namedTag = new ncache.NamedTagsDictionary();
namedTag.add("Discount", 0.4);
attributes.setNamedTags(namedTag);

// Create list with attributes
var list = await (
await this.cache.getDataStructuresManager()
).createList(key, Number(), attributes, null);

// Adding Product IDs to HashSet
var productIDs = this.fetchProductIDs();
for (var productID in productIDs) {
// Add product IDs to HashSet
list.add(productID);
}
// You can query on this list using these attributes

Note

To ensure that the operation is fail-safe, it is recommended to handle any potential exceptions within your application, as explained in Handling Failures.

Additional Resources

NCache provides a sample application for configuring searchable attributes with data structures on GitHub.

Configure Searchable Attributes for Data Structures in Cache

Important

Prerequisites

Tip

Note

Additional Resources

See Also

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