/*

 * Copyright (c) 2013, 2018, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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 General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package jdk.jfr.internal.instrument;

import java.io.IOException;

import jdk.jfr.events.FileReadEvent;

/**

 * See {@link JITracer} for an explanation of this code.

 */

@JIInstrumentationTarget("java.io.FileInputStream")

final class FileInputStreamInstrumentor {

    private FileInputStreamInstrumentor() {

    }

    private String path;

    @SuppressWarnings("deprecation")

    @JIInstrumentationMethod

    public int read() throws IOException {

        FileReadEvent event = FileReadEvent.EVENT.get();

        if (!event.isEnabled()) {

            return read();

        }

        int result = 0;

        try {

            event.begin();

            result = read();

            if (result < 0) {

                event.endOfFile = true;

            } else {

                event.bytesRead = 1;

            }

        } finally {

            event.path = path;

            event.commit();

            event.reset();

        }

        return result;

    }

    @SuppressWarnings("deprecation")

    @JIInstrumentationMethod

    public int read(byte b[]) throws IOException {

        FileReadEvent event = FileReadEvent.EVENT.get();

        if (!event.isEnabled()) {

            return read(b);

        }

        int bytesRead = 0;

        try {

            event.begin();

            bytesRead = read(b);

        } finally {

            if (bytesRead < 0) {

                event.endOfFile = true;

            } else {

                event.bytesRead = bytesRead;

            }

            event.path = path;

            event.commit();

            event.reset();

        }

        return bytesRead;

    }

    @SuppressWarnings("deprecation")

    @JIInstrumentationMethod

    public int read(byte b[], int off, int len) throws IOException {

        FileReadEvent event = FileReadEvent.EVENT.get();

        if (!event.isEnabled()) {

            return read(b, off, len);

        }

        int bytesRead = 0;

        try {

            event.begin();

            bytesRead = read(b, off, len);

        } finally {

            if (bytesRead < 0) {

                event.endOfFile = true;

            } else {

                event.bytesRead = bytesRead;

            }

            event.path = path;

            event.commit();

            event.reset();

        }

        return bytesRead;

    }

}