/**
* 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.thrift;
import java.io.BufferedOutputStream ;
import java.io.InputStream ;
import java.io.OutputStream ;
import java.util.List ;
import java.util.function.Consumer;
import org.apache.jena.atlas.io.IO ;
import org.apache.jena.atlas.io.IndentedWriter ;
import org.apache.jena.query.ResultSet ;
import org.apache.jena.riot.system.PrefixMap ;
import org.apache.jena.riot.system.PrefixMapFactory ;
import org.apache.jena.riot.system.StreamRDF ;
import org.apache.jena.riot.thrift.wire.RDF_StreamRow ;
import org.apache.jena.sparql.core.Var ;
import org.apache.jena.sparql.engine.ResultSetStream ;
import org.apache.jena.sparql.engine.binding.Binding ;
import org.apache.thrift.TException ;
import org.apache.thrift.protocol.TProtocol ;
import org.apache.thrift.transport.TTransportException ;
/** Operations on binary RDF (which uses <a href="http://thrift.apache.org/">Apache Thrift</a>).
* See also {@link ThriftConvert}, for specific functions on binary RDF.
* @see ThriftConvert
*/
public class BinRDF {
private static int BUFSIZE_IN = 128*1024 ;
private static int BUFSIZE_OUT = 128*1024 ;
/**
* Create an {@link StreamRDF} for output. A filename ending {@code .gz} will have
* a gzip compressor added to the output path. A filename of "-" is {@code System.out}.
* The file is closed when {@link StreamRDF#finish()} is called unless it is {@code System.out}.
* Call {@link StreamRDF#start()}...{@link StreamRDF#finish()}.
*
* @param filename The file
* @return StreamRDF A stream to send to.
*/
public static StreamRDF streamToFile(String filename) {
return streamToFile(filename, false) ;
}
/**
* Create an {@link StreamRDF} for output. A filename ending {@code .gz} will have
* a gzip compressor added to the output path. A filename of "-" is {@code System.out}.
* The file is closed when {@link StreamRDF#finish()} is called unless it is {@code System.out}.
* Call {@link StreamRDF#start()}...{@link StreamRDF#finish()}.
*
* @param filename The file
* @param withValues - whether to encode numeric values as values.
* @return StreamRDF A stream to send to.
*/
public static StreamRDF streamToFile(String filename, boolean withValues) {
OutputStream out = IO.openOutputFile(filename) ;
// Is this internally buffered as well?
BufferedOutputStream bout = new BufferedOutputStream(out, BUFSIZE_OUT) ;
TProtocol protocol = TRDF.protocol(bout) ;
return new StreamRDF2Thrift(protocol, withValues) ;
}
/**
* Create an {@link StreamRDF} for output.
* The {@code OutputStream} is closed when {@link StreamRDF#finish()} is called unless it is {@code System.out}.
* Call {@link StreamRDF#start()}...{@link StreamRDF#finish()}.
* @param out OutputStream
* @return StreamRDF A stream to send to.
*/
public static StreamRDF streamToOutputStream(OutputStream out) {
return streamToOutputStream(out, false) ;
}
/**
* Create an {@link StreamRDF} for output.
* The {@code OutputStream} is closed when {@link StreamRDF#finish()} is called unless it is {@code System.out}.
* Call {@link StreamRDF#start()}...{@link StreamRDF#finish()}.
* @param out OutputStream
* @param withValues - whether to encode numeric values as values.
* @return StreamRDF A stream to send to.
*/
public static StreamRDF streamToOutputStream(OutputStream out, boolean withValues) {
return new StreamRDF2Thrift(out, withValues) ;
}
/**
* Create an {@link StreamRDF} for output.
* The {@code OutputStream} is closed when {@link StreamRDF#finish()} is called unless it is {@code System.out}.
* Call {@link StreamRDF#start()}...{@link StreamRDF#finish()}.
* @param protocol Output and encoding.
* @return StreamRDF A stream to send to.
*/
public static StreamRDF streamToTProtocol(TProtocol protocol) {
return streamToTProtocol(protocol, false) ;
}
/**
* Create an {@link StreamRDF} for output.
* The {@code OutputStream} is closed when {@link StreamRDF#finish()} is called unless it is {@code System.out}.
* Call {@link StreamRDF#start()}...{@link StreamRDF#finish()}.
* @param protocol Output and encoding.
* @param withValues - whether to encode numeric values as values.
* @return StreamRDF A stream to send to.
*/
public static StreamRDF streamToTProtocol(TProtocol protocol, boolean withValues) {
return new StreamRDF2Thrift(protocol, withValues) ;
}
/**
* Decode the contents of the file and send to the {@link StreamRDF}.
* A filename ending {@code .gz} will have a gzip decompressor added.
* A filename of "-" is {@code System.in}.
* @param filename The file.
* @param dest Sink
*/
public static void fileToStream(String filename, StreamRDF dest) {
InputStream in = IO.openFile(filename) ;
TProtocol protocol = TRDF.protocol(in) ;
protocolToStream(protocol, dest) ;
}
/**
* Decode the contents of the input stream and send to the {@link StreamRDF}.
* @param in InputStream
* @param dest StreamRDF
*/
public static void inputStreamToStream(InputStream in, StreamRDF dest) {
TProtocol protocol = TRDF.protocol(in) ;
protocolToStream(protocol, dest) ;
}
/**
* Decode the contents of the TProtocol and send to the {@link StreamRDF}.
* @param protocol TProtocol
* @param dest Sink
*/
public static void protocolToStream(TProtocol protocol, StreamRDF dest) {
PrefixMap pmap = PrefixMapFactory.create() ;
final Thrift2StreamRDF s = new Thrift2StreamRDF(pmap, dest) ;
dest.start() ;
// ** Java8
//apply(protocol, z -> TRDF.visit(z, s)) ;
applyVisitor(protocol, s) ;
dest.finish() ;
// No need to flush - we read from the protocol ;
}
// ** Java7 support
public static void applyVisitor(TProtocol protocol, final VisitorStreamRowTRDF visitor) {
apply(protocol, z -> TRDF.visit(z, visitor)) ;
}
/**
* Send the contents of a RDF-encoded Thrift file to an "action"
* @param protocol TProtocol
* @param action Code to act on the row.
*/
public static void apply(TProtocol protocol, Consumer<RDF_StreamRow> action) {
RDF_StreamRow row = new RDF_StreamRow() ;
while(protocol.getTransport().isOpen()) {
try { row.read(protocol) ; }
catch (TTransportException e) {
if ( e.getType() == TTransportException.END_OF_FILE )
break ;
}
catch (TException ex) { TRDF.exception(ex) ; }
action.accept(row) ;
row.clear() ;
}
}
/** Debug help - print details of a Thrift stream.
* Destructive on the InputStream.
* @param out OutputStream
* @param in InputStream
*/
public static void dump(OutputStream out, InputStream in) {
IndentedWriter iOut = new IndentedWriter(out) ;
StreamRowTRDFPrinter printer = new StreamRowTRDFPrinter(iOut) ;
TProtocol protocol = TRDF.protocol(in) ;
BinRDF.applyVisitor(protocol, printer) ;
iOut.flush() ;
}
public static ResultSet readResultSet(InputStream in) {
return readResultSet(TRDF.protocol(in)) ;
}
public static ResultSet readResultSet(TProtocol protocol) {
Thift2Binding t2b = new Thift2Binding(protocol) ;
List<String> varsNames = Var.varNames(t2b.getVars()) ;
return new ResultSetStream(varsNames, null, t2b) ;
}
public static void writeResultSet(OutputStream out, ResultSet resultSet) {
writeResultSet(out, resultSet, false) ;
}
public static void writeResultSet(OutputStream out, ResultSet resultSet, boolean withValues) {
BufferedOutputStream bout =
( out instanceof BufferedOutputStream )
? (BufferedOutputStream)out
: new BufferedOutputStream(out, TRDF.OutputBufferSize) ;
writeResultSet(TRDF.protocol(bout), resultSet, withValues) ;
IO.flush(out) ;
}
public static void writeResultSet(TProtocol protocol, ResultSet resultSet) {
writeResultSet(protocol, resultSet, false) ;
}
public static void writeResultSet(TProtocol protocol, ResultSet resultSet, boolean encodeValues) {
List<Var> vars = Var.varList(resultSet.getResultVars()) ;
try ( Binding2Thrift b2t = new Binding2Thrift(protocol, vars, encodeValues) ) {
for ( ; resultSet.hasNext() ; ) {
Binding b = resultSet.nextBinding() ;
b2t.output(b) ;
}
}
//Done by Binding2Thrift.close() -- LibThriftRDF.flush(protocol) ;
}
}