VirtualFileStore.java

package automately.core.file;

import io.jsync.AsyncResult;
import io.jsync.Handler;
import io.jsync.app.core.Cluster;
import io.jsync.buffer.Buffer;

import java.io.File;

/**
 * The VirtualFileStore interface is a very important interface that is used by
 * the VirtualFileService to store your data in a central location within the cluster.
 * It acts as a central point of storage so all of your data can be persistent instead of
 * inconsistent.
 */
public interface VirtualFileStore {

    /**
     * This is called when the VirtualFileStore is first initialized. This is used so
     * you can access the Cluster object.
     * @param cluster
     */
    void initialize(Cluster cluster);

    void stop();

    File toFile(VirtualFile file);

    /**
     * This is used to retrieve the data for the VirtualFile
     *
     * @return data for the VirtualFile
     */
    Buffer readRawData(VirtualFile file);

    /**
     * This allows you to retrieve data for a VirtualFile asynchronously.
     *
     * @param file the VirtualFile you wish to retrieve data for
     * @param asyncResultHandler the handler with the file data
     */
    void readRawData(VirtualFile file, Handler<AsyncResult<Buffer>> asyncResultHandler);

    /**
     * This is used to write the data for the VirtualFile.
     *
     * @param file the file you wish to write the data to
     * @param data the data you wish to write
     */
    void writeRawData(VirtualFile file, Buffer data);

    /**
     * This is used to write the data for the VirtualFile asynchronously.
     *
     * @param file the file you wish to write the data to
     * @param data the data you wish to write
     * @param asyncResultHandler the handle which tells you if the write succeeded or not
     */
    void writeRawData(VirtualFile file, Buffer data, Handler<AsyncResult<Void>> asyncResultHandler);

    /**
     * This is used to effectively delete a file from the file system. This is
     * called only by the VirtualFileSystem when a file is no longer referenced.
     *
     * @param file the file you wish to delete
     */
    void deleteFile(VirtualFile file);

    /**
     * This is used to asynchronously delete a file from the file system.
     * @param file the file you wish to delete
     * @param asyncResultHandler a handler that is triggered when the file is deleted
     */
    void deleteFile(VirtualFile file, Handler<AsyncResult<Void>> asyncResultHandler);

    /**
     * This method is used by the VirtualFileService to help ensure that all the nodes are synced up
     * and reading the same data for a specified file. The VirtualFileService will randomly attempt to verify data. At the initial startup
     * of a node it'll attempt to verify a specific file.
     *
     * @param file The file that is being validated
     * @param hash The hash of the contents
     * @return returns true or false on success
     */
    boolean verifyNode(VirtualFile file, String hash);

}