Java tutorial
/* * Copyright (c) 2013 Cisco Systems, Inc. and others. All rights reserved. * * This program and the accompanying materials are made available under the * terms of the Eclipse Public License v1.0 which accompanies this distribution, * and is available at http://www.eclipse.org/legal/epl-v10.html */ package org.opendaylight.protocol.pcep.spi; import com.google.common.base.Optional; import com.google.common.base.Preconditions; import com.google.common.primitives.UnsignedBytes; import io.netty.buffer.ByteBuf; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; import java.util.List; import javax.annotation.Nullable; import org.opendaylight.protocol.util.BitArray; import org.opendaylight.protocol.util.ByteArray; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.iana.rev130816.EnterpriseNumber; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.message.rev131007.PcerrBuilder; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.Message; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.Object; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.ObjectHeader; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.pcep.error.object.ErrorObjectBuilder; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.pcerr.message.PcerrMessageBuilder; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.pcerr.message.pcerr.message.ErrorsBuilder; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.pcerr.message.pcerr.message.error.type.RequestCaseBuilder; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.pcerr.message.pcerr.message.error.type.request._case.RequestBuilder; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.pcerr.message.pcerr.message.error.type.request._case.request.RpsBuilder; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.rp.object.Rp; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.vendor.information.objects.VendorInformationObject; public abstract class AbstractMessageParser implements MessageParser, MessageSerializer { private static final int COMMON_OBJECT_HEADER_LENGTH = 4; private static final int OT_SF_LENGTH = 4; /* * offsets of fields inside of multi-field in bits */ private static final int OT_SF_OFFSET = 0; /* * flags offsets inside multi-filed */ private static final int PROCESSED = 6; private static final int IGNORED = 7; private final ObjectRegistry registry; protected AbstractMessageParser(final ObjectRegistry registry) { this.registry = Preconditions.checkNotNull(registry); } /** * Calls registry to pick up specific object serializer for given object. * Checks if the object is not null. * @param object Object to be serialized, may be null * @param buffer ByteBuf where the object should be serialized */ protected void serializeObject(@Nullable final Object object, final ByteBuf buffer) { if (object == null) { return; } this.registry.serializeObject(object, buffer); } private List<Object> parseObjects(final ByteBuf bytes) throws PCEPDeserializerException { final List<Object> objs = new ArrayList<>(); while (bytes.isReadable()) { if (bytes.readableBytes() < COMMON_OBJECT_HEADER_LENGTH) { throw new PCEPDeserializerException("Too few bytes in passed array. Passed: " + bytes.readableBytes() + " Expected: >= " + COMMON_OBJECT_HEADER_LENGTH + "."); } final int objClass = bytes.readUnsignedByte(); final byte flagsByte = bytes.readByte(); final BitArray flags = BitArray.valueOf(flagsByte); final int objType = UnsignedBytes.toInt(ByteArray.copyBitsRange(flagsByte, OT_SF_OFFSET, OT_SF_LENGTH)); final int objLength = bytes.readUnsignedShort(); if (bytes.readableBytes() < objLength - COMMON_OBJECT_HEADER_LENGTH) { throw new PCEPDeserializerException("Too few bytes in passed array. Passed: " + bytes.readableBytes() + " Expected: >= " + objLength + "."); } // copy bytes for deeper parsing final ByteBuf bytesToPass = bytes.readSlice(objLength - COMMON_OBJECT_HEADER_LENGTH); final ObjectHeader header = new ObjectHeaderImpl(flags.get(PROCESSED), flags.get(IGNORED)); if (VendorInformationUtil.isVendorInformationObject(objClass, objType)) { final EnterpriseNumber enterpriseNumber = new EnterpriseNumber(bytesToPass.readUnsignedInt()); final Optional<? extends Object> obj = this.registry.parseVendorInformationObject(enterpriseNumber, header, bytesToPass); if (obj.isPresent()) { objs.add(obj.get()); } } else { // parseObject is required to return null for P=0 errored objects final Object o = this.registry.parseObject(objClass, objType, header, bytesToPass); if (o != null) { objs.add(o); } } } return objs; } public static Message createErrorMsg(final PCEPErrors e, final Optional<Rp> rp) { final PcerrMessageBuilder msgBuilder = new PcerrMessageBuilder(); if (rp.isPresent()) { new RequestCaseBuilder() .setRequest(new RequestBuilder() .setRps(Collections.singletonList(new RpsBuilder().setRp(rp.get()).build())).build()) .build(); } return new PcerrBuilder().setPcerrMessage(msgBuilder.setErrors(Arrays.asList(new ErrorsBuilder() .setErrorObject( new ErrorObjectBuilder().setType(e.getErrorType()).setValue(e.getErrorValue()).build()) .build())).build()).build(); } protected abstract Message validate(final List<Object> objects, final List<Message> errors) throws PCEPDeserializerException; @Override public final Message parseMessage(final ByteBuf buffer, final List<Message> errors) throws PCEPDeserializerException { Preconditions.checkNotNull(buffer, "Buffer may not be null"); // Parse objects first final List<Object> objs = parseObjects(buffer); // Run validation return validate(objs, errors); } protected final void serializeVendorInformationObjects(final List<VendorInformationObject> viObjects, final ByteBuf buffer) { if (viObjects != null) { for (final VendorInformationObject viObject : viObjects) { this.registry.serializeVendorInformationObject(viObject, buffer); } } } protected final List<VendorInformationObject> addVendorInformationObjects(final List<Object> objects) { final List<VendorInformationObject> vendorInfo = new ArrayList<>(); while (!objects.isEmpty() && objects.get(0) instanceof VendorInformationObject) { final VendorInformationObject viObject = (VendorInformationObject) objects.get(0); vendorInfo.add(viObject); objects.remove(0); } return vendorInfo; } }