org.apache.arrow.flight.FlightDescriptor.java Source code

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Here is the source code for org.apache.arrow.flight.FlightDescriptor.java

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/*
 * 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.arrow.flight;

import java.util.List;

import org.apache.arrow.flight.impl.Flight;
import org.apache.arrow.flight.impl.Flight.FlightDescriptor.DescriptorType;

import com.google.common.base.Joiner;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;
import com.google.protobuf.ByteString;

/**
 * An identifier for a particular set of data.  This can either be an opaque command that generates
 * the data or a static "path" to the data.  This is a POJO wrapper around the protobuf message with
 * the same name.
 */
public class FlightDescriptor {

    private boolean isCmd;
    private List<String> path;
    private byte[] cmd;

    private FlightDescriptor(boolean isCmd, List<String> path, byte[] cmd) {
        super();
        this.isCmd = isCmd;
        this.path = path;
        this.cmd = cmd;
    }

    public static FlightDescriptor command(byte[] cmd) {
        return new FlightDescriptor(true, null, cmd);
    }

    public static FlightDescriptor path(Iterable<String> path) {
        return new FlightDescriptor(false, ImmutableList.copyOf(path), null);
    }

    public static FlightDescriptor path(String... path) {
        return new FlightDescriptor(false, ImmutableList.copyOf(path), null);
    }

    FlightDescriptor(Flight.FlightDescriptor descriptor) {
        if (descriptor.getType() == DescriptorType.CMD) {
            isCmd = true;
            cmd = descriptor.getCmd().toByteArray();
        } else if (descriptor.getType() == DescriptorType.PATH) {
            isCmd = false;
            path = descriptor.getPathList();
        } else {
            throw new UnsupportedOperationException();
        }
    }

    public boolean isCommand() {
        return isCmd;
    }

    public List<String> getPath() {
        Preconditions.checkArgument(!isCmd);
        return path;
    }

    public byte[] getCommand() {
        Preconditions.checkArgument(isCmd);
        return cmd;
    }

    Flight.FlightDescriptor toProtocol() {
        Flight.FlightDescriptor.Builder b = Flight.FlightDescriptor.newBuilder();

        if (isCmd) {
            return b.setType(DescriptorType.CMD).setCmd(ByteString.copyFrom(cmd)).build();
        }
        return b.setType(DescriptorType.PATH).addAllPath(path).build();
    }

    @Override
    public String toString() {
        if (isCmd) {
            return toHex(cmd);
        } else {
            return Joiner.on('.').join(path);
        }
    }

    private String toHex(byte[] bytes) {
        StringBuilder sb = new StringBuilder();
        for (byte b : bytes) {
            sb.append(String.format("%02X ", b));
        }
        return sb.toString();
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((cmd == null) ? 0 : cmd.hashCode());
        result = prime * result + (isCmd ? 1231 : 1237);
        result = prime * result + ((path == null) ? 0 : path.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj == null) {
            return false;
        }
        if (getClass() != obj.getClass()) {
            return false;
        }
        FlightDescriptor other = (FlightDescriptor) obj;
        if (cmd == null) {
            if (other.cmd != null) {
                return false;
            }
        } else if (!cmd.equals(other.cmd)) {
            return false;
        }
        if (isCmd != other.isCmd) {
            return false;
        }
        if (path == null) {
            if (other.path != null) {
                return false;
            }
        } else if (!path.equals(other.path)) {
            return false;
        }
        return true;
    }

}