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Access to the Neo4j graph database through Java
/*
* Copyright (c) 2002-2017 "Neo Technology,"
* Network Engine for Objects in Lund AB [http://neotechnology.com]
*
* This file is part of Neo4j.
*
* Licensed 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.neo4j.driver.internal.messaging;
import java.io.IOException;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.WritableByteChannel;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import org.neo4j.driver.internal.InternalNode;
import org.neo4j.driver.internal.InternalPath;
import org.neo4j.driver.internal.InternalRelationship;
import org.neo4j.driver.internal.net.BufferingChunkedInput;
import org.neo4j.driver.internal.net.ChunkedOutput;
import org.neo4j.driver.internal.packstream.PackInput;
import org.neo4j.driver.internal.packstream.PackOutput;
import org.neo4j.driver.internal.packstream.PackStream;
import org.neo4j.driver.internal.packstream.PackType;
import org.neo4j.driver.internal.util.Iterables;
import org.neo4j.driver.internal.value.InternalValue;
import org.neo4j.driver.internal.value.ListValue;
import org.neo4j.driver.internal.value.MapValue;
import org.neo4j.driver.internal.value.NodeValue;
import org.neo4j.driver.internal.value.PathValue;
import org.neo4j.driver.internal.value.RelationshipValue;
import org.neo4j.driver.v1.Value;
import org.neo4j.driver.v1.exceptions.ClientException;
import org.neo4j.driver.v1.types.Entity;
import org.neo4j.driver.v1.types.Node;
import org.neo4j.driver.v1.types.Path;
import org.neo4j.driver.v1.types.Relationship;
import static org.neo4j.driver.v1.Values.value;
public class PackStreamMessageFormatV1 implements MessageFormat
{
public final static byte MSG_INIT = 0x01;
public final static byte MSG_ACK_FAILURE = 0x0E;
public final static byte MSG_RESET = 0x0F;
public final static byte MSG_RUN = 0x10;
public final static byte MSG_DISCARD_ALL = 0x2F;
public final static byte MSG_PULL_ALL = 0x3F;
public final static byte MSG_RECORD = 0x71;
public final static byte MSG_SUCCESS = 0x70;
public final static byte MSG_IGNORED = 0x7E;
public final static byte MSG_FAILURE = 0x7F;
public static final byte NODE = 'N';
public static final byte RELATIONSHIP = 'R';
public static final byte UNBOUND_RELATIONSHIP = 'r';
public static final byte PATH = 'P';
public static final int VERSION = 1;
public static final int NODE_FIELDS = 3;
private static final Map EMPTY_STRING_VALUE_MAP = new HashMap<>( 0 );
@Override
public MessageFormat.Writer newWriter( WritableByteChannel ch )
{
ChunkedOutput output = new ChunkedOutput( ch );
return new Writer( output, output.messageBoundaryHook() );
}
@Override
public MessageFormat.Reader newReader( ReadableByteChannel ch )
{
BufferingChunkedInput input = new BufferingChunkedInput( ch );
return new Reader( input, input.messageBoundaryHook() );
}
@Override
public int version()
{
return VERSION;
}
public static class Writer implements MessageFormat.Writer, MessageHandler
{
private final PackStream.Packer packer;
private final Runnable onMessageComplete;
/**
* @param output interface to write messages to
* @param onMessageComplete invoked for each message, after it's done writing to the output
*/
public Writer( PackOutput output, Runnable onMessageComplete )
{
this.onMessageComplete = onMessageComplete;
packer = new PackStream.Packer( output );
}
@Override
public void handleInitMessage( String clientNameAndVersion, Map authToken ) throws IOException
{
packer.packStructHeader( 1, MSG_INIT );
packer.pack( clientNameAndVersion );
packRawMap( authToken );
onMessageComplete.run();
}
@Override
public void handleRunMessage( String statement, Map parameters ) throws IOException
{
packer.packStructHeader( 2, MSG_RUN );
packer.pack( statement );
packRawMap( parameters );
onMessageComplete.run();
}
@Override
public void handlePullAllMessage() throws IOException
{
packer.packStructHeader( 0, MSG_PULL_ALL );
onMessageComplete.run();
}
@Override
public void handleDiscardAllMessage() throws IOException
{
packer.packStructHeader( 0, MSG_DISCARD_ALL );
onMessageComplete.run();
}
@Override
public void handleResetMessage() throws IOException
{
packer.packStructHeader( 0, MSG_RESET );
onMessageComplete.run();
}
@Override
public void handleAckFailureMessage() throws IOException
{
packer.packStructHeader( 0, MSG_ACK_FAILURE );
onMessageComplete.run();
}
@Override
public void handleSuccessMessage( Map meta ) throws IOException
{
packer.packStructHeader( 1, MSG_SUCCESS );
packRawMap( meta );
onMessageComplete.run();
}
@Override
public void handleRecordMessage( Value[] fields ) throws IOException
{
packer.packStructHeader( 1, MSG_RECORD );
packer.packListHeader( fields.length );
for ( Value field : fields )
{
packValue( field );
}
onMessageComplete.run();
}
@Override
public void handleFailureMessage( String code, String message ) throws IOException
{
packer.packStructHeader( 1, MSG_FAILURE );
packer.packMapHeader( 2 );
packer.pack( "code" );
packValue( value( code ) );
packer.pack( "message" );
packValue( value( message ) );
onMessageComplete.run();
}
@Override
public void handleIgnoredMessage() throws IOException
{
packer.packStructHeader( 0, MSG_IGNORED );
onMessageComplete.run();
}
private void packRawMap( Map map ) throws IOException
{
if ( map == null || map.size() == 0 )
{
packer.packMapHeader( 0 );
return;
}
packer.packMapHeader( map.size() );
for ( Map.Entry entry : map.entrySet() )
{
packer.pack( entry.getKey() );
packValue( entry.getValue() );
}
}
private void packValue( Value value ) throws IOException
{
switch ( ( (InternalValue) value ).typeConstructor() )
{
case NULL_TyCon:
packer.packNull();
break;
case STRING_TyCon:
packer.pack( value.asString() );
break;
case BOOLEAN_TyCon:
packer.pack( value.asBoolean() );
break;
case INTEGER_TyCon:
packer.pack( value.asLong() );
break;
case FLOAT_TyCon:
packer.pack( value.asDouble() );
break;
case MAP_TyCon:
packer.packMapHeader( value.size() );
for ( String s : value.keys() )
{
packer.pack( s );
packValue( value.get( s ) );
}
break;
case LIST_TyCon:
packer.packListHeader( value.size() );
for ( Value item : value.values() )
{
packValue( item );
}
break;
case NODE_TyCon:
{
Node node = value.asNode();
packNode( node );
}
break;
case RELATIONSHIP_TyCon:
{
Relationship rel = value.asRelationship();
packer.packStructHeader( 5, RELATIONSHIP );
packer.pack( rel.id() );
packer.pack( rel.startNodeId() );
packer.pack( rel.endNodeId() );
packer.pack( rel.type() );
packProperties( rel );
}
break;
case PATH_TyCon:
Path path = value.asPath();
packer.packStructHeader( 3, PATH );
// Unique nodes
Map nodeIdx = new LinkedHashMap<>();
for ( Node node : path.nodes() )
{
if ( !nodeIdx.containsKey( node ) )
{
nodeIdx.put( node, nodeIdx.size() );
}
}
packer.packListHeader( nodeIdx.size() );
for ( Node node : nodeIdx.keySet() )
{
packNode( node );
}
// Unique rels
Map relIdx = new LinkedHashMap<>();
for ( Relationship rel : path.relationships() )
{
if ( !relIdx.containsKey( rel ) )
{
relIdx.put( rel, relIdx.size() + 1 );
}
}
packer.packListHeader( relIdx.size() );
for ( Relationship rel : relIdx.keySet() )
{
packer.packStructHeader( 3, UNBOUND_RELATIONSHIP );
packer.pack( rel.id() );
packer.pack( rel.type() );
packProperties( rel );
}
// Sequence
packer.packListHeader( path.length() * 2 );
for ( Path.Segment seg : path )
{
Relationship rel = seg.relationship();
long relEndId = rel.endNodeId();
long segEndId = seg.end().id();
packer.pack( relEndId == segEndId ? relIdx.get( rel ) : -relIdx.get( rel ) );
packer.pack( nodeIdx.get( seg.end() ) );
}
break;
default:
throw new IOException( "Unknown type: " + value );
}
}
@Override
public Writer flush() throws IOException
{
packer.flush();
return this;
}
@Override
public Writer write( Message msg ) throws IOException
{
msg.dispatch( this );
return this;
}
private void packNode( Node node ) throws IOException
{
packer.packStructHeader( NODE_FIELDS, NODE );
packer.pack( node.id() );
Iterable labels = node.labels();
packer.packListHeader( Iterables.count( labels ) );
for ( String label : labels )
{
packer.pack( label );
}
packProperties( node );
}
private void packProperties( Entity entity ) throws IOException
{
Iterable keys = entity.keys();
packer.packMapHeader( entity.size() );
for ( String propKey : keys )
{
packer.pack( propKey );
packValue( entity.get( propKey ) );
}
}
}
public static class Reader implements MessageFormat.Reader
{
private final PackStream.Unpacker unpacker;
private final Runnable onMessageComplete;
public Reader( PackInput input, Runnable onMessageComplete )
{
unpacker = new PackStream.Unpacker( input );
this.onMessageComplete = onMessageComplete;
}
@Override
public boolean hasNext() throws IOException
{
return unpacker.hasNext();
}
/**
* Parse a single message into the given consumer.
*/
@Override
public void read( MessageHandler handler ) throws IOException
{
unpacker.unpackStructHeader();
int type = unpacker.unpackStructSignature();
switch ( type )
{
case MSG_RUN:
unpackRunMessage( handler );
break;
case MSG_DISCARD_ALL:
unpackDiscardAllMessage( handler );
break;
case MSG_PULL_ALL:
unpackPullAllMessage( handler );
break;
case MSG_RECORD:
unpackRecordMessage(handler);
break;
case MSG_SUCCESS:
unpackSuccessMessage( handler );
break;
case MSG_FAILURE:
unpackFailureMessage( handler );
break;
case MSG_IGNORED:
unpackIgnoredMessage( handler );
break;
case MSG_INIT:
unpackInitMessage( handler );
break;
case MSG_RESET:
unpackResetMessage( handler );
break;
default:
throw new IOException( "Unknown message type: " + type );
}
}
private void unpackResetMessage( MessageHandler handler ) throws IOException
{
handler.handleResetMessage();
onMessageComplete.run();
}
private void unpackInitMessage( MessageHandler handler ) throws IOException
{
handler.handleInitMessage( unpacker.unpackString(), unpackMap() );
onMessageComplete.run();
}
private void unpackIgnoredMessage( MessageHandler output ) throws IOException
{
output.handleIgnoredMessage();
onMessageComplete.run();
}
private void unpackFailureMessage( MessageHandler output ) throws IOException
{
Map params = unpackMap();
String code = params.get( "code" ).asString();
String message = params.get( "message" ).asString();
output.handleFailureMessage( code, message );
onMessageComplete.run();
}
private void unpackRunMessage( MessageHandler output ) throws IOException
{
String statement = unpacker.unpackString();
Map params = unpackMap();
output.handleRunMessage( statement, params );
onMessageComplete.run();
}
private void unpackDiscardAllMessage( MessageHandler output ) throws IOException
{
output.handleDiscardAllMessage();
onMessageComplete.run();
}
private void unpackPullAllMessage( MessageHandler output ) throws IOException
{
output.handlePullAllMessage();
onMessageComplete.run();
}
private void unpackSuccessMessage( MessageHandler output ) throws IOException
{
Map map = unpackMap();
output.handleSuccessMessage( map );
onMessageComplete.run();
}
private void unpackRecordMessage(MessageHandler output) throws IOException
{
int fieldCount = (int) unpacker.unpackListHeader();
Value[] fields = new Value[fieldCount];
for ( int i = 0; i < fieldCount; i++ )
{
fields[i] = unpackValue();
}
output.handleRecordMessage( fields );
onMessageComplete.run();
}
private Value unpackValue() throws IOException
{
PackType type = unpacker.peekNextType();
switch ( type )
{
case BYTES:
break;
case NULL:
return value( unpacker.unpackNull() );
case BOOLEAN:
return value( unpacker.unpackBoolean() );
case INTEGER:
return value( unpacker.unpackLong() );
case FLOAT:
return value( unpacker.unpackDouble() );
case STRING:
return value( unpacker.unpackString() );
case MAP:
{
return new MapValue( unpackMap() );
}
case LIST:
{
int size = (int) unpacker.unpackListHeader();
Value[] vals = new Value[size];
for ( int j = 0; j < size; j++ )
{
vals[j] = unpackValue();
}
return new ListValue( vals );
}
case STRUCT:
{
long size = unpacker.unpackStructHeader();
switch ( unpacker.unpackStructSignature() )
{
case NODE:
ensureCorrectStructSize( "NODE", NODE_FIELDS, size );
InternalNode adapted = unpackNode();
return new NodeValue( adapted );
case RELATIONSHIP:
ensureCorrectStructSize( "RELATIONSHIP", 5, size );
return unpackRelationship();
case PATH:
ensureCorrectStructSize( "PATH", 3, size );
return unpackPath();
}
}
}
throw new IOException( "Unknown value type: " + type );
}
private Value unpackRelationship() throws IOException
{
long urn = unpacker.unpackLong();
long startUrn = unpacker.unpackLong();
long endUrn = unpacker.unpackLong();
String relType = unpacker.unpackString();
Map props = unpackMap();
InternalRelationship adapted = new InternalRelationship( urn, startUrn, endUrn, relType, props );
return new RelationshipValue( adapted );
}
private InternalNode unpackNode() throws IOException
{
long urn = unpacker.unpackLong();
int numLabels = (int) unpacker.unpackListHeader();
List labels = new ArrayList<>( numLabels );
for ( int i = 0; i < numLabels; i++ )
{
labels.add( unpacker.unpackString() );
}
int numProps = (int) unpacker.unpackMapHeader();
Map props = new HashMap<>();
for ( int j = 0; j < numProps; j++ )
{
String key = unpacker.unpackString();
props.put( key, unpackValue() );
}
return new InternalNode( urn, labels, props );
}
private Value unpackPath() throws IOException
{
// List of unique nodes
Node[] uniqNodes = new Node[(int) unpacker.unpackListHeader()];
for ( int i = 0; i < uniqNodes.length; i++ )
{
ensureCorrectStructSize( "NODE", NODE_FIELDS, unpacker.unpackStructHeader() );
ensureCorrectStructSignature( "NODE", NODE, unpacker.unpackStructSignature() );
uniqNodes[i] = unpackNode();
}
// List of unique relationships, without start/end information
InternalRelationship[] uniqRels = new InternalRelationship[(int) unpacker.unpackListHeader()];
for ( int i = 0; i < uniqRels.length; i++ )
{
ensureCorrectStructSize( "RELATIONSHIP", 3, unpacker.unpackStructHeader() );
ensureCorrectStructSignature( "UNBOUND_RELATIONSHIP", UNBOUND_RELATIONSHIP, unpacker.unpackStructSignature() );
long id = unpacker.unpackLong();
String relType = unpacker.unpackString();
Map props = unpackMap();
uniqRels[i] = new InternalRelationship( id, -1, -1, relType, props );
}
// Path sequence
int length = (int) unpacker.unpackListHeader();
// Knowing the sequence length, we can create the arrays that will represent the nodes, rels and segments in their "path order"
Path.Segment[] segments = new Path.Segment[length / 2];
Node[] nodes = new Node[segments.length + 1];
Relationship[] rels = new Relationship[segments.length];
Node prevNode = uniqNodes[0], nextNode; // Start node is always 0, and isn't encoded in the sequence
nodes[0] = prevNode;
InternalRelationship rel;
for ( int i = 0; i < segments.length; i++ )
{
int relIdx = (int) unpacker.unpackLong();
nextNode = uniqNodes[(int) unpacker.unpackLong()];
// Negative rel index means this rel was traversed "inversed" from its direction
if( relIdx < 0 )
{
rel = uniqRels[(-relIdx) - 1]; // -1 because rel idx are 1-indexed
rel.setStartAndEnd( nextNode.id(), prevNode.id() );
}
else
{
rel = uniqRels[relIdx - 1];
rel.setStartAndEnd( prevNode.id(), nextNode.id() );
}
nodes[i+1] = nextNode;
rels[i] = rel;
segments[i] = new InternalPath.SelfContainedSegment( prevNode, rel, nextNode );
prevNode = nextNode;
}
return new PathValue( new InternalPath( Arrays.asList( segments ), Arrays.asList( nodes ), Arrays.asList( rels ) ) );
}
private void ensureCorrectStructSize( String structName, int expected, long actual )
{
if ( expected != actual )
{
throw new ClientException( String.format(
"Invalid message received, serialized %s structures should have %d fields, "
+ "received %s structure has %d fields.", structName, expected, structName, actual ) );
}
}
private void ensureCorrectStructSignature( String structName, byte expected, byte actual )
{
if ( expected != actual )
{
throw new ClientException( String.format(
"Invalid message received, expected a `%s`, signature 0x%s. Recieved signature was 0x%s.",
structName, Integer.toHexString( expected ), Integer.toHexString( actual ) ) );
}
}
private Map unpackMap() throws IOException
{
int size = (int) unpacker.unpackMapHeader();
if ( size == 0 )
{
return EMPTY_STRING_VALUE_MAP;
}
Map map = new HashMap<>( size );
for ( int i = 0; i < size; i++ )
{
String key = unpacker.unpackString();
map.put( key, unpackValue() );
}
return map;
}
}
public static class NoOpRunnable implements Runnable
{
@Override
public void run()
{
// no-op
}
}
}
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