protocols/p4runtime/utils/src/main/java/org/onosproject/p4runtime/ctl/codec/DirectMeterEntryCodec.java

/*
 * Copyright 2019-present Open Networking Foundation
 *
 * 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.onosproject.p4runtime.ctl.codec;

import org.onosproject.net.pi.model.PiPipeconf;
import org.onosproject.net.pi.runtime.PiMeterCellConfig;
import org.onosproject.net.pi.runtime.PiMeterCellHandle;
import org.onosproject.net.pi.runtime.PiMeterCellId;
import org.onosproject.p4runtime.ctl.utils.P4InfoBrowser;
import p4.v1.P4RuntimeOuterClass;

import static org.onosproject.p4runtime.ctl.codec.Codecs.CODECS;

/**
 * Codec for P4Runtime DirectMeterEntryCodec.
 */
public final class DirectMeterEntryCodec
        extends AbstractEntityCodec<PiMeterCellConfig, PiMeterCellHandle,
        P4RuntimeOuterClass.DirectMeterEntry, Object> {

    @Override
    protected P4RuntimeOuterClass.DirectMeterEntry encode(
            PiMeterCellConfig piEntity, Object ignored, PiPipeconf pipeconf,
            P4InfoBrowser browser)
            throws CodecException {
        P4RuntimeOuterClass.DirectMeterEntry.Builder builder =
            P4RuntimeOuterClass.DirectMeterEntry.newBuilder()
                .setTableEntry(CODECS.tableEntry().encode(
                        piEntity.cellId().tableEntry(), null, pipeconf));
        // We keep the config field unset if it is reset scenario
        P4RuntimeOuterClass.MeterConfig meterConfig = MeterEntryCodec.getP4Config(piEntity);
        if (meterConfig != null) {
            builder = builder.setConfig(meterConfig);
        }
        return builder.build();
    }

    @Override
    protected P4RuntimeOuterClass.DirectMeterEntry encodeKey(
            PiMeterCellHandle handle, Object metadata, PiPipeconf pipeconf,
            P4InfoBrowser browser)
            throws CodecException {
        return keyMsgBuilder(handle.cellId(), pipeconf).build();
    }

    @Override
    protected P4RuntimeOuterClass.DirectMeterEntry encodeKey(
            PiMeterCellConfig piEntity, Object metadata,
            PiPipeconf pipeconf, P4InfoBrowser browser)
            throws CodecException {
        return keyMsgBuilder(piEntity.cellId(), pipeconf).build();
    }

    private P4RuntimeOuterClass.DirectMeterEntry.Builder keyMsgBuilder(
            PiMeterCellId cellId, PiPipeconf pipeconf)
            throws CodecException {
        return P4RuntimeOuterClass.DirectMeterEntry.newBuilder()
                .setTableEntry(CODECS.tableEntry().encodeKey(
                        cellId.tableEntry(), null, pipeconf));
    }

    @Override
    protected PiMeterCellConfig decode(
            P4RuntimeOuterClass.DirectMeterEntry message, Object ignored,
            PiPipeconf pipeconf, P4InfoBrowser browser)
            throws CodecException {
        PiMeterCellId cellId =
            PiMeterCellId.ofDirect(
                CODECS.tableEntry().decode(
                    message.getTableEntry(), null, pipeconf));
        // When a field is unset, gRPC (P4RT) will return a default value
        // So, if the meter config is unset, the value of rate and burst will be 0,
        // while 0 is a meaningful value and not equals to UNSET in P4RT.
        // We cannot extract the values directly.
        P4RuntimeOuterClass.MeterConfig p4Config =
            message.hasConfig() ? message.getConfig() : null;

        return MeterEntryCodec.getPiMeterCellConfig(cellId, p4Config);
    }
}