jena-arq/src/main/java/org/apache/jena/riot/RIOT.java

/*
 * 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.jena.riot ;

import org.apache.jena.atlas.lib.Version;
import org.apache.jena.riot.lang.rdfxml.RRX;
import org.apache.jena.riot.resultset.ResultSetLang;
import org.apache.jena.riot.system.StreamRDF;
import org.apache.jena.riot.writer.DirectiveStyle;
import org.apache.jena.sparql.SystemARQ ;
import org.apache.jena.sparql.util.Context ;
import org.apache.jena.sparql.util.MappingRegistry;
import org.apache.jena.sparql.util.Symbol ;
import org.apache.jena.sys.JenaSystem ;

public class RIOT {
    // Initialization statics must be first in the class to avoid
    // problems with recursive initialization.
    private static volatile boolean initialized = false ;
    private static Object           initLock    = new Object() ;

    /** IRI for RIOT */
    public static final String riotIRI = "http://jena.apache.org/#riot" ;

    /** The product name */
    public static final String NAME    = "RIOT" ;

    // Unsafe to touch ARQ in class initialization
    // See init(). these are set in register()
    // public static final String VERSION = NAME+"/"+ARQ.VERSION ;
    // public static final String BUILD_DATE = ARQ.BUILD_DATE ;

    public static final String       VERSION = Version.versionForClass(RIOT.class).orElse("<development>");;

    /** The root package name for RIOT */
    public static final String PATH    = "org.apache.jena.riot" ;

    /** Control of multiline literals */
    public static final Symbol multilineLiterals = Symbol.create("riot.multiline_literals") ;

    /** The system-wide context, shared with ARQ and other modules. */
    private static Context systemGlobalContext = new Context();

    public static Context getContext() {
        return systemGlobalContext;
    }

    public static void init() {
        if ( initialized )
            return ;
        synchronized (initLock) {
            if ( initialized ) {
                JenaSystem.logLifecycle("RIOT.init - skip") ;
                return ;
            }
            initialized = true ;

            JenaSystem.logLifecycle("RIOT.init - start") ;
            // Protect against unexpected initialization ordering.
            if ( systemGlobalContext == null ) {
                JenaSystem.logLifecycle("RIOT.init - Warning: initializing systemGlobalContext in RIOT.init") ;
                systemGlobalContext = new Context();
            }
            setRIOTSettings();

            RDFLanguages.init() ;
            RDFParserRegistry.init() ;
            RDFWriterRegistry.init() ;
            ResultSetLang.init();

            MappingRegistry.addPrefixMapping("rdfxml", RDFXML_SYMBOL_BASE) ;
            MappingRegistry.addPrefixMapping("ttl", TURTLE_SYMBOL_BASE) ;
            MappingRegistry.addPrefixMapping("trig", TURTLE_SYMBOL_BASE) ;

            IO_Jena.wireIntoJena() ;

            // Don't register JMX info with ARQ as it may not be initialized
            // itself and we can get into a circularity.
            // This is done in ARQ.init at the proper moment.
            JenaSystem.logLifecycle("RIOT.init - finish") ;
        }
    }

    private static void setRIOTSettings() {
        // RIOT has no global defaults in the context.
    }

    private static boolean registered = false ;

    public static void register() {
        if ( registered )
            return ;
        registered = true ;
    }

    public static String getVersion() {
        return RIOT.VERSION ;
    }

    // ---- Symbols

    private static String TURTLE_SYMBOL_BASE = "http://jena.apache.org/riot/turtle#";
    private static String RDFXML_SYMBOL_BASE = "http://jena.apache.org/riot/rdfxml#";

    /**
     * Legacy access to the original legacy RDF/XML parser.
     * The original ARP parser will be removed.
     * Use {@link Lang} constant {@link RRX#RDFXML_ARP1} or {@link RRX#RDFXML_ARP0}
     * to access ARP v1 (RIOT integration) or ARP v0 (the original ARP parser).
     * @deprecated Do not use this symbol! This will be removed.
     */
    @Deprecated
    public static Symbol symRDFXML0 = SystemARQ.allocSymbol(RDFXML_SYMBOL_BASE, "rdfxml0");

    /**
     * Printing style - {@code PREFIX} or {@code @prefix}
     *  - {@link DirectiveStyle}, one of {@code AT} or {@code KEYWORD}.
     * <p>
     * The context value is:
     * <ul>
     * <li>
     * One of {@link DirectiveStyle#KEYWORD}, "rdf_11", "rdf11" or "sparql"
     * to have {@code PREFIX} and {@code BASE}</li>
     * <ll>
     *  One of {@link DirectiveStyle#AT}," rdf_10", "rdf10" or  "at" to have {@code @prefix} and {@code @base}
     * </li>
     * The system default is {@link DirectiveStyle#KEYWORD}.
     * </ul>
     */
    public static final Symbol symTurtleDirectiveStyle = SystemARQ.allocSymbol(TURTLE_SYMBOL_BASE, "directiveStyle");

    /**
     * Printing style. Whether to output "BASE"/"@base" (according to
     * {@link #symTurtleDirectiveStyle} or not. BASE is normally written if there is
     * a base URI passed to the writer or, for a streaming writer, if
     * {@link StreamRDF#base} is called. If this context setting is set true, then do
     * not output BASE even when given.
     */
    public static final Symbol symTurtleOmitBase = SystemARQ.allocSymbol(TURTLE_SYMBOL_BASE, "omitBase");

    /**
     * Printing style. Whether to use a "wide" or "long" indentation style.
     */
    public static final Symbol symTurtleIndentStyle = SystemARQ.allocSymbol(TURTLE_SYMBOL_BASE, "indentStyle");
}