org.jpmml.xgboost.XGBoostDataInput.java Source code

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Here is the source code for org.jpmml.xgboost.XGBoostDataInput.java

Source

/*
 * Copyright (c) 2016 Villu Ruusmann
 *
 * This file is part of JPMML-XGBoost
 *
 * JPMML-XGBoost is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * JPMML-XGBoost is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with JPMML-XGBoost.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.jpmml.xgboost;

import java.io.Closeable;
import java.io.IOException;
import java.io.InputStream;
import java.io.PushbackInputStream;
import java.util.Arrays;

import com.google.common.io.ByteStreams;
import com.google.common.io.LittleEndianDataInputStream;

public class XGBoostDataInput implements Closeable {

    private LittleEndianDataInputStream dis = null;

    public XGBoostDataInput(InputStream is) throws IOException {
        this.dis = new LittleEndianDataInputStream(init(new PushbackInputStream(is, 4)));
    }

    @Override
    public void close() throws IOException {
        this.dis.close();
    }

    public int readInt() throws IOException {
        return this.dis.readInt();
    }

    public float readFloat() throws IOException {
        return this.dis.readFloat();
    }

    public String readString() throws IOException {
        int length = (int) this.dis.readLong();

        byte[] buffer = new byte[length];

        ByteStreams.readFully(this.dis, buffer);

        return new String(buffer);
    }

    public void readReserved(int length) throws IOException {

        for (int i = 0; i < length; i++) {
            int value = this.dis.readInt();

            if (value != 0) {
                throw new IOException();
            }
        }
    }

    static private InputStream init(PushbackInputStream is) throws IOException {
        byte[] header = new byte[4];

        ByteStreams.readFully(is, header);

        if (!Arrays.equals(XGBoostDataInput.BINF_MAGIC, header)) {
            is.unread(header);
        }

        return is;
    }

    private static final byte[] BINF_MAGIC = { 'b', 'i', 'n', 'f' };
}