io.delta.flink.source.internal.enumerator.supplier.SnapshotSupplier Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of delta-flink Show documentation

delta-flink

There is a newer version: 3.2.1

package io.delta.flink.source.internal.enumerator.supplier;

import io.delta.flink.internal.options.DeltaConnectorConfiguration;
import io.delta.flink.source.internal.utils.TransitiveOptional;

import io.delta.standalone.DeltaLog;
import io.delta.standalone.Snapshot;

/**
 * This class abstract's logic needed to acquirer Delta table {@link Snapshot} based on {@link
 * DeltaConnectorConfiguration} and any other implementation specific logic.
 */
public abstract class SnapshotSupplier {

    /**
     * The {@link DeltaLog} instance that will be used to get the desire {@link Snapshot} instance.
     */
    protected final DeltaLog deltaLog;

    protected SnapshotSupplier(DeltaLog deltaLog) {
        this.deltaLog = deltaLog;
    }

    /**
     * @return A {@link Snapshot} instance acquired from {@link #deltaLog}. Every implementation of
     * {@link SnapshotSupplier} class can have its own rules about how snapshot should be acquired.
     */
    public abstract Snapshot getSnapshot(DeltaConnectorConfiguration sourceConfiguration);

    /**
     * A helper method that returns the latest {@link Snapshot} at moment when this method was
     * called.
     * 
     * If underlying Delta table, represented by {@link #deltaLog} field is changing, for example a
     * new data is being added to the table, every call to this method can return different {@link
     * Snapshot}.
     */
    protected TransitiveOptional getHeadSnapshot() {
        return TransitiveOptional.ofNullable(deltaLog.snapshot());
    }
}