6.1. Driver API

The Driver API is the core of integration of multiple Object Storage solutions. Each integration must implement this interface in order to be able to add this as a plugin within Cloud Cloud Store.

6.1.1. Global logic of API

Relation between Cloud Cloud Store, Driver and Object Storage

6.1.2. 3 implementations

There are 3 implementations:

• S3 like support (whatever Amazon, Minio or any S3 compatible implementations)

• Azure Blob Storage support

• Google Cloud Storage support

All of these implementations respect the API of the Driver.

6.1.3. Driver API details

The DriverApiFactory might be created by explicitly create the right implementation (for instance Arc.container().select(DriverApiFactory.class).get();).

The DriverApi is then created through this Factory with factory.getInstance().

However, each DriverApiFactory must register once configured within DriverApiRegister, such that the factory is get using DriverApiRegister.getDriverApiFactory().

Note that all methods accept both String for Bucket / Object and StorageBucket / StorageObject, except bucketCreate and objectPrepareCreateInBucket since those methods need a full StorageBucket or StorageObject.

For instance: bucketDelete(String bucket) can be written as bucketDelete(StorageBucket bucket), or objectGetInputStreamInBucket(String bucket, String object) as objectGetInputStreamInBucket(StorageObject object)

6.1.3.1. Bucket operations

Java API for Buckets

/**
 * Count Buckets
 */
long bucketsCount() throws DriverException;

/**
 * List Buckets
 */
Stream<StorageBucket> bucketsList() throws DriverException;

Java API for Bucket

/**
 * Create one Bucket and returns it
 *
 * @param bucket contains various information that could be implemented within Object Storage, but, except the name
 *               of the bucket, nothing is mandatory
 * @return the StorageBucket as instantiated within the Object Storage (real values)
 */
StorageBucket bucketCreate(StorageBucket bucket)
    throws DriverNotAcceptableException, DriverAlreadyExistException, DriverException;

/**
 * Delete one Bucket if it exists and is empty
 */
void bucketDelete(String bucket) throws DriverNotAcceptableException, DriverNotFoundException, DriverException;

/**
 * Check existence of Bucket
 */
boolean bucketExists(String bucket) throws DriverException;

6.1.3.2. Object operations

Java API for Objects

/**
 * Count Objects in specified Bucket
 */
long objectsCountInBucket(final String bucket) throws DriverNotFoundException, DriverException;

/**
 * Count Objects in specified Bucket with filters (all optionals)
 */
long objectsCountInBucket(String bucket, String prefix, Instant from, Instant to)
    throws DriverNotFoundException, DriverException;

/**
 * List Objects in specified Bucket.
 */
Stream<StorageObject> objectsListInBucket(String bucket)
    throws DriverNotFoundException, DriverException;

/**
 * List Objects in specified Bucket with filters (all optionals)
 */
Stream<StorageObject> objectsListInBucket(String bucket, String prefix, Instant from, Instant to)
    throws DriverNotFoundException, DriverException;

Java API for Object

/**
 * Check if Directory or Object exists in specified Bucket (based on prefix)
 */
StorageType directoryOrObjectExistsInBucket(final String bucket, final String directoryOrObject)
    throws DriverException;

/**
 * First step in creation of an object within a Bucket. The InputStream is ready to be read in
 * a concurrent independent thread to be provided by the driver. Sha256 might be null or empty. Len might be 0,
 * meaning unknown.
 *
 * @param object contains various information that could be implemented within Object Storage, but, except the name
 *               of the bucket and the key of the object, nothing is mandatory
 */
void objectPrepareCreateInBucket(StorageObject object, InputStream inputStream)
    throws DriverNotFoundException, DriverAlreadyExistException, DriverException;

/**
 * Second step in creation of an object within a Bucket. Sha256 might be null or empty. Reallen must not be 0.
 * This method waits for the prepare method to end and returns the final result.
 *
 * @return the StorageObject as instantiated within the Object Storage (real values)
 */
StorageObject objectFinalizeCreateInBucket(String bucket, String object, long realLen, String sha256)
    throws DriverNotFoundException, DriverAlreadyExistException, DriverException;

/**
 * Get the content of the specified Object within specified Bucket
 */
InputStream objectGetInputStreamInBucket(String bucket, String object) throws DriverNotFoundException,
    DriverException;

/**
 * Get the Object metadata from this Bucket (those available from Object Storage)
 */
StorageObject objectGetMetadataInBucket(String bucket, String object)
    throws DriverNotFoundException, DriverException;

/**
 * Delete the Object from this Bucket
 */
void objectDeleteInBucket(String bucket, String object)
    throws DriverNotAcceptableException, DriverNotFoundException, DriverException;