com.torodb.mongowp.server.encoder.ReplyMessageEncoder.java Source code

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Here is the source code for com.torodb.mongowp.server.encoder.ReplyMessageEncoder.java

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/*
 * Copyright 2014 8Kdata Technology
 *
 * 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 com.torodb.mongowp.server.encoder;

import com.google.common.collect.FluentIterable;
import com.torodb.mongowp.bson.BsonDocument;
import com.torodb.mongowp.bson.netty.NettyBsonDocumentWriter;
import com.torodb.mongowp.bson.utils.BsonDocumentReader.AllocationType;
import com.torodb.mongowp.messages.response.ReplyMessage;
import com.torodb.mongowp.messages.response.ResponseOpCode;
import com.torodb.mongowp.server.util.EnumBitFlags;
import com.torodb.mongowp.server.util.EnumInt32FlagsUtil;
import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
import io.netty.buffer.ByteBuf;

import java.util.EnumSet;

import javax.annotation.Nonnegative;
import javax.annotation.concurrent.ThreadSafe;
import javax.inject.Inject;

/**
 *
 */
@SuppressFBWarnings(value = "RV_RETURN_VALUE_IGNORED_NO_SIDE_EFFECT", justification = "It seems FindBugs considers ByteBuf methods are not side effect")
@ThreadSafe
public class ReplyMessageEncoder {

    private final NettyBsonDocumentWriter writer;

    @Inject
    public ReplyMessageEncoder(NettyBsonDocumentWriter writer) {
        this.writer = writer;
    }

    public void encodeMessageHeader(ByteBuf buffer, ReplyMessage message, int requestId) {
        buffer.writeInt(requestId);
        buffer.writeInt(message.getResponseTo());
        buffer.writeInt(ResponseOpCode.OP_REPLY.getOpCode());
    }

    public void encodeMessageBody(ByteBuf buffer, ReplyMessage message) {
        FluentIterable<? extends BsonDocument> docs = message.getDocuments().getIterable(AllocationType.HEAP);

        buffer.writeInt(EnumInt32FlagsUtil.getInt32Flags(extractFlags(message)));
        buffer.writeLong(message.getCursorId());
        buffer.writeInt(message.getStartingFrom());
        buffer.writeInt(docs.size());

        for (BsonDocument document : docs) {
            writer.writeInto(buffer, document);
        }
    }

    private EnumSet<Flag> extractFlags(ReplyMessage message) {
        EnumSet<Flag> flags = EnumSet.noneOf(Flag.class);
        if (message.isCursorNotFound()) {
            flags.add(Flag.CURSOR_NOT_FOUND);
        }
        if (message.isQueryFailure()) {
            flags.add(Flag.QUERY_FAILURE);
        }
        if (message.isShardConfigStale()) {
            flags.add(Flag.SHARD_CONFIG_STALE);
        }
        if (message.isAwaitCapable()) {
            flags.add(Flag.AWAIT_CAPABLE);
        }
        return flags;
    }

    private enum Flag implements EnumBitFlags {
        CURSOR_NOT_FOUND(0), QUERY_FAILURE(1), SHARD_CONFIG_STALE(2), AWAIT_CAPABLE(3);

        @Nonnegative
        private final int flagBitPosition;

        private Flag(@Nonnegative int flagBitPosition) {
            this.flagBitPosition = flagBitPosition;
        }

        @Override
        public int getFlagBitPosition() {
            return flagBitPosition;
        }
    }
}