1 /*
   2  * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 #include <fcntl.h>
  27 #include <limits.h>
  28 
  29 #include "jni.h"
  30 #include "jni_util.h"
  31 #include "jlong.h"
  32 #include "io_util.h"
  33 
  34 #include "jvm.h"
  35 
  36 #include "java_io_FileInputStream.h"
  37 
  38 #include "io_util_md.h"
  39 
  40 /*******************************************************************/
  41 /*  BEGIN JNI ********* BEGIN JNI *********** BEGIN JNI ************/
  42 /*******************************************************************/
  43 
  44 jfieldID fis_fd; /* id for jobject 'fd' in java.io.FileInputStream */
  45 jfieldID fis_pgsz; /* id for jobject 'pageSize' in java.io.FileInputStream */
  46 
  47 /**************************************************************
  48  * static methods to store field ID's in initializers
  49  */
  50 
  51 JNIEXPORT void JNICALL
  52 Java_java_io_FileInputStream_initIDs(JNIEnv *env, jclass fdClass) {
  53     fis_fd = (*env)->GetFieldID(env, fdClass, "fd", "Ljava/io/FileDescriptor;");
  54     fis_pgsz = (*env)->GetFieldID(env, fdClass, "pageSize", "I");
  55 }
  56 
  57 /**************************************************************
  58  * Input stream
  59  */
  60 
  61 JNIEXPORT jint JNICALL
  62 Java_java_io_FileInputStream_read0(JNIEnv *env, jobject this) {
  63     return readSingle(env, this, fis_fd);
  64 }
  65 
  66 JNIEXPORT jint JNICALL
  67 Java_java_io_FileInputStream_readBytes(JNIEnv *env, jobject this,
  68         jbyteArray bytes, jint off, jint len) {
  69     return readBytes(env, this, bytes, off, len, fis_fd);
  70 }
  71 
  72 JNIEXPORT jlong JNICALL
  73 Java_java_io_FileInputStream_skip(JNIEnv *env, jobject this, jlong toSkip) {
  74     jlong cur = jlong_zero;
  75     jlong end = jlong_zero;
  76     FD fd = GET_FD(this, fis_fd);
  77     if (fd == -1) {
  78         JNU_ThrowIOException (env, "Stream Closed");
  79         return 0;
  80     }
  81     if ((cur = IO_Lseek(fd, (jlong)0, (jint)SEEK_CUR)) == -1) {
  82         JNU_ThrowIOExceptionWithLastError(env, "Seek error");
  83     } else if ((end = IO_Lseek(fd, toSkip, (jint)SEEK_CUR)) == -1) {
  84         JNU_ThrowIOExceptionWithLastError(env, "Seek error");
  85     }
  86     return (end - cur);
  87 }
  88 
  89 JNIEXPORT jint JNICALL
  90 Java_java_io_FileInputStream_available(JNIEnv *env, jobject this) {
  91     jlong ret;
  92     FD fd = GET_FD(this, fis_fd);
  93     if (fd == -1) {
  94         JNU_ThrowIOException (env, "Stream Closed");
  95         return 0;
  96     }
  97     if (IO_Available(fd, &ret)) {
  98         if (ret > INT_MAX) {
  99             ret = (jlong) INT_MAX;
 100         } else if (ret < 0) {
 101             ret = 0;
 102         }
 103         return jlong_to_jint(ret);
 104     }
 105     JNU_ThrowIOExceptionWithLastError(env, NULL);
 106     return 0;
 107 }