| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| |
| package org.apache.tinkerpop.gremlin.structure.io; |
| |
| import org.apache.tinkerpop.gremlin.process.computer.KeyValue; |
| import org.apache.tinkerpop.gremlin.structure.Vertex; |
| |
| import java.util.Iterator; |
| import java.util.List; |
| |
| /** |
| * Storage is a standard API that providers can implement to allow "file-system"-based access to data sources. |
| * The methods provided by Storage are similar in form and behavior to standard Linux operating system commands. |
| * |
| * @author Marko A. Rodriguez (http://markorodriguez.com) |
| */ |
| public interface Storage { |
| |
| /** |
| * List all the data sources in the root directory. |
| * |
| * @return the data sources in the root directory |
| */ |
| public List<String> ls(); |
| |
| /** |
| * List all the data sources at the specified location. |
| * |
| * @param location a location |
| * @return the data sources at the specified location |
| */ |
| public List<String> ls(final String location); |
| |
| /** |
| * Recursively copy all the data sources from the source location to the target location. |
| * |
| * @param sourceLocation the source location |
| * @param targetLocation the target location |
| * @return whether data sources were copied |
| */ |
| public boolean cp(final String sourceLocation, final String targetLocation); |
| |
| /** |
| * Determine whether the specified location has a data source. |
| * |
| * @param location a location to check |
| * @return whether that location has a data source. |
| */ |
| public boolean exists(final String location); |
| |
| /** |
| * Recursively remove the data source at the specified location. |
| * |
| * @param location the location of the data source |
| * @return whether a data source was removed. |
| */ |
| public boolean rm(final String location); |
| |
| /** |
| * Get a string representation of the specified number of lines at the data source location. |
| * |
| * @param location the data source location |
| * @return an iterator of lines |
| */ |
| public default Iterator<String> head(final String location) { |
| return this.head(location, Integer.MAX_VALUE); |
| } |
| |
| /** |
| * Get a string representation of the specified number of lines at the data source location. |
| * |
| * @param location the data source location |
| * @param totalLines the total number of lines to retrieve |
| * @return an iterator of lines. |
| */ |
| public Iterator<String> head(final String location, final int totalLines); |
| |
| /** |
| * Get the vertices at the specified graph location. |
| * |
| * @param location the location of the graph (or the root location and search will be made) |
| * @param parserClass the class of the parser that understands the graph format |
| * @param totalLines the total number of lines of the graph to return |
| * @return an iterator of vertices. |
| */ |
| public Iterator<Vertex> head(final String location, final Class parserClass, final int totalLines); |
| |
| /** |
| * Get the vertices at the specified graph location. |
| * |
| * @param location the location of the graph (or the root location and search will be made) |
| * @param parserClass the class of the parser that understands the graph format |
| * @return an iterator of vertices. |
| */ |
| public default Iterator<Vertex> head(final String location, final Class parserClass) { |
| return this.head(location, parserClass, Integer.MAX_VALUE); |
| } |
| |
| /** |
| * Get the {@link KeyValue} data at the specified memory location. |
| * |
| * @param location the root location of the data |
| * @param memoryKey the memory key |
| * @param parserClass the class of the parser that understands the memory format |
| * @param totalLines the total number of key-values to return |
| * @return an iterator of key-values. |
| */ |
| public <K, V> Iterator<KeyValue<K, V>> head(final String location, final String memoryKey, final Class parserClass, final int totalLines); |
| |
| |
| /** |
| * Get the {@link KeyValue} data at the specified memory location. |
| * |
| * @param location the root location of the data |
| * @param memoryKey the memory key |
| * @param parserClass the class of the parser that understands the memory format |
| * @return an iterator of key-values. |
| */ |
| public default <K, V> Iterator<KeyValue<K, V>> head(final String location, final String memoryKey, final Class parserClass) { |
| return this.head(location, memoryKey, parserClass, Integer.MAX_VALUE); |
| } |
| } |