/*
 * Copyright 2010 - 2023 JetBrains s.r.o.
 *
 * 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
 *
 * https://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 jetbrains.exodus.util;

import java.io.ByteArrayInputStream;

public class ByteArraySizedInputStream extends ByteArrayInputStream {

    public ByteArraySizedInputStream(byte[] buf) {
        super(buf);
    }

    public ByteArraySizedInputStream(byte[] buf, int offset, int length) {
        super(buf, offset, length);
    }

    public int size() {
        return count - mark;
    }

    public int count() {
        return count;
    }

    public int pos() {
        return pos;
    }

    public void setPos(final int pos) {
        this.pos = pos;
    }

    public byte[] toByteArray() {
        return buf;
    }

    public ByteArraySizedInputStream copy() {
        return new ByteArraySizedInputStream(buf, pos, count);
    }

    @Override
    public int hashCode() {
        int result = size() + 1;
        final int mark = this.mark;
        final int count = this.count;
        final byte[] buf = this.buf;
        for (int i = mark; i < count; ++i) {
            result = result * 31 + buf[i];
        }
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (!(obj instanceof ByteArraySizedInputStream)) return false;
        final ByteArraySizedInputStream right = (ByteArraySizedInputStream) obj;
        final int size = size();
        if (size != right.size()) return false;
        final int mark = this.mark;
        final byte[] buf = this.buf;
        final int rMark = right.mark;
        final byte[] rBuf = this.buf;
        for (int i = 0; i < size; ++i) {
            if (buf[i + mark] != rBuf[i + rMark]) return false;
        }
        return true;
    }
}
