/*

 * 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 <stdlib.h>

#include <string.h>

#include <stddef.h>

#include "jni.h"

#include "jni_util.h"

#include "jvm.h"

#include "io_util.h"

#include "io_util_md.h"

/* IO helper functions */

jint

readSingle(JNIEnv *env, jobject this, jfieldID fid) {

    jint nread;

    char ret;

    FD fd = GET_FD(this, fid);

    if (fd == -1) {

        JNU_ThrowIOException(env, "Stream Closed");

        return -1;

    }

    nread = IO_Read(fd, &ret, 1);

    if (nread == 0) { /* EOF */

        return -1;

    } else if (nread == -1) { /* error */

        JNU_ThrowIOExceptionWithLastError(env, "Read error");

    }

    return ret & 0xFF;

}

/* The maximum size of a stack-allocated buffer.

 */

#define BUF_SIZE 8192

/*

 * Returns true if the array slice defined by the given offset and length

 * is out of bounds.

 */

static int

outOfBounds(JNIEnv *env, jint off, jint len, jbyteArray array) {

    return ((off < 0) ||

            (len < 0) ||

            // We are very careful to avoid signed integer overflow,

            // the result of which is undefined in C.

            ((*env)->GetArrayLength(env, array) - off < len));

}

jint

readBytes(JNIEnv *env, jobject this, jbyteArray bytes,

          jint off, jint len, jfieldID fid)

{

    jint nread;

    char stackBuf[BUF_SIZE];

    char *buf = NULL;

    FD fd;

    if (IS_NULL(bytes)) {

        JNU_ThrowNullPointerException(env, NULL);

        return -1;

    }

    if (outOfBounds(env, off, len, bytes)) {

        JNU_ThrowByName(env, "java/lang/IndexOutOfBoundsException", NULL);

        return -1;

    }

    if (len == 0) {

        return 0;

    } else if (len > BUF_SIZE) {

        buf = malloc(len);

        if (buf == NULL) {

            JNU_ThrowOutOfMemoryError(env, NULL);

            return 0;

        }

    } else {

        buf = stackBuf;

    }

    fd = GET_FD(this, fid);

    if (fd == -1) {

        JNU_ThrowIOException(env, "Stream Closed");

        nread = -1;

    } else {

        nread = IO_Read(fd, buf, len);

        if (nread > 0) {

            (*env)->SetByteArrayRegion(env, bytes, off, nread, (jbyte *)buf);

        } else if (nread == -1) {

            JNU_ThrowIOExceptionWithLastError(env, "Read error");

        } else { /* EOF */

            nread = -1;

        }

    }

    if (buf != stackBuf) {

        free(buf);

    }

    return nread;

}

void

writeSingle(JNIEnv *env, jobject this, jint byte, jboolean append, jfieldID fid) {

    // Discard the 24 high-order bits of byte. See OutputStream#write(int)

    char c = (char) byte;

    jint n;

    FD fd = GET_FD(this, fid);

    if (fd == -1) {

        JNU_ThrowIOException(env, "Stream Closed");

        return;

    }

    if (append == JNI_TRUE) {

        n = IO_Append(fd, &c, 1);

    } else {

        n = IO_Write(fd, &c, 1);

    }

    if (n == -1) {

        JNU_ThrowIOExceptionWithLastError(env, "Write error");

    }

}

void

writeBytes(JNIEnv *env, jobject this, jbyteArray bytes,

           jint off, jint len, jboolean append, jfieldID fid)

{

    jint n;

    char stackBuf[BUF_SIZE];

    char *buf = NULL;

    FD fd;

    if (IS_NULL(bytes)) {

        JNU_ThrowNullPointerException(env, NULL);

        return;

    }

    if (outOfBounds(env, off, len, bytes)) {

        JNU_ThrowByName(env, "java/lang/IndexOutOfBoundsException", NULL);

        return;

    }

    if (len == 0) {

        return;

    } else if (len > BUF_SIZE) {

        buf = malloc(len);

        if (buf == NULL) {

            JNU_ThrowOutOfMemoryError(env, NULL);

            return;

        }

    } else {

        buf = stackBuf;

    }

    (*env)->GetByteArrayRegion(env, bytes, off, len, (jbyte *)buf);

    if (!(*env)->ExceptionOccurred(env)) {

        off = 0;

        while (len > 0) {

            fd = GET_FD(this, fid);

            if (fd == -1) {

                JNU_ThrowIOException(env, "Stream Closed");

                break;

            }

            if (append == JNI_TRUE) {

                n = IO_Append(fd, buf+off, len);

            } else {

                n = IO_Write(fd, buf+off, len);

            }

            if (n == -1) {

                JNU_ThrowIOExceptionWithLastError(env, "Write error");

                break;

            }

            off += n;

            len -= n;

        }

    }

    if (buf != stackBuf) {

        free(buf);

    }

}

throwFileNotFoundException(JNIEnv *env, jstring path)

{

    char buf[256];

    size_t n;

    jobject x;

    jstring why = NULL;

    n = getLastErrorString(buf, sizeof(buf));

    if (n > 0) {

#ifdef WIN32

        why = (*env)->NewStringUTF(env, buf);

#else

        why = JNU_NewStringPlatform(env, buf);

#endif

        CHECK_NULL(why);

    }

    x = JNU_NewObjectByName(env,

                            "java/io/FileNotFoundException",

                            "(Ljava/lang/String;Ljava/lang/String;)V",

                            path, why);

    if (x != NULL) {

        (*env)->Throw(env, x);

    }

}