/*

 * Copyright (c) 2014, 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.

 */

#include <windows.h>

#include "jni_util.h"

#include "jlong.h"

#include "jdk_internal_jimage_concurrent_ConcurrentPReader.h"

static jfieldID handle_fdID;

JNIEXPORT void JNICALL

Java_jdk_internal_jimage_concurrent_ConcurrentPReader_initIDs(JNIEnv *env, jclass clazz)

{

    CHECK_NULL(clazz = (*env)->FindClass(env, "java/io/FileDescriptor"));

    CHECK_NULL(handle_fdID = (*env)->GetFieldID(env, clazz, "handle", "J"));

}

JNIEXPORT jint JNICALL

Java_jdk_internal_jimage_concurrent_ConcurrentPReader_pread(JNIEnv *env, jclass clazz,

                                                            jobject fdo, jlong address,

                                                            jint len, jlong offset)

{

    OVERLAPPED ov;

    DWORD nread;

    BOOL result;

    jlong handle = (*env)->GetLongField(env, fdo, handle_fdID);

    void *buf = (void *)jlong_to_ptr(address);

    ZeroMemory(&ov, sizeof(ov));

    ov.Offset = (DWORD)offset;

    ov.OffsetHigh = (DWORD)(offset >> 32);

    result = ReadFile(handle, (LPVOID)buf, len, &nread, &ov);

    if (result == 0) {

        JNU_ThrowIOExceptionWithLastError(env, "ReadFile failed");

    }

    return nread;

}