SimpleDataInput.java

/*
 * Copyright (C) 2012, Google Inc. and others
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Distribution License v. 1.0 which is available at
 * https://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

package org.eclipse.jgit.internal.storage.file;

import java.io.DataInput;
import java.io.IOException;
import java.io.InputStream;

import org.eclipse.jgit.util.IO;
import org.eclipse.jgit.util.NB;

/**
 * An implementation of DataInput that only handles readInt() and readLong()
 * using the Git conversion utilities for network byte order handling. This is
 * needed to read {@link com.googlecode.javaewah.EWAHCompressedBitmap}s.
 */
class SimpleDataInput implements DataInput {
    private final InputStream fd;

    private final byte[] buf = new byte[8];

    SimpleDataInput(InputStream fd) {
        this.fd = fd;
    }

    /** {@inheritDoc} */
    @Override
    public int readInt() throws IOException {
        readFully(buf, 0, 4);
        return NB.decodeInt32(buf, 0);
    }

    /** {@inheritDoc} */
    @Override
    public long readLong() throws IOException {
        readFully(buf, 0, 8);
        return NB.decodeInt64(buf, 0);
    }

    /**
     * Read unsigned int
     *
     * @return a long.
     * @throws java.io.IOException
     *             if any.
     */
    public long readUnsignedInt() throws IOException {
        readFully(buf, 0, 4);
        return NB.decodeUInt32(buf, 0);
    }

    /** {@inheritDoc} */
    @Override
    public void readFully(byte[] b) throws IOException {
        readFully(b, 0, b.length);
    }

    /** {@inheritDoc} */
    @Override
    public void readFully(byte[] b, int off, int len) throws IOException {
        IO.readFully(fd, b, off, len);
    }

    /** {@inheritDoc} */
    @Override
    public int skipBytes(int n) throws IOException {
        throw new UnsupportedOperationException();
    }

    /** {@inheritDoc} */
    @Override
    public boolean readBoolean() throws IOException {
        throw new UnsupportedOperationException();
    }

    /** {@inheritDoc} */
    @Override
    public byte readByte() throws IOException {
        throw new UnsupportedOperationException();
    }

    /** {@inheritDoc} */
    @Override
    public int readUnsignedByte() throws IOException {
        throw new UnsupportedOperationException();
    }

    /** {@inheritDoc} */
    @Override
    public short readShort() throws IOException {
        throw new UnsupportedOperationException();
    }

    /** {@inheritDoc} */
    @Override
    public int readUnsignedShort() throws IOException {
        throw new UnsupportedOperationException();
    }

    /** {@inheritDoc} */
    @Override
    public char readChar() throws IOException {
        throw new UnsupportedOperationException();
    }

    /** {@inheritDoc} */
    @Override
    public float readFloat() throws IOException {
        throw new UnsupportedOperationException();
    }

    /** {@inheritDoc} */
    @Override
    public double readDouble() throws IOException {
        throw new UnsupportedOperationException();
    }

    /** {@inheritDoc} */
    @Override
    public String readLine() throws IOException {
        throw new UnsupportedOperationException();
    }

    /** {@inheritDoc} */
    @Override
    public String readUTF() throws IOException {
        throw new UnsupportedOperationException();
    }
}