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      1 /*
      2  * Copyright (c) 1997, 2007, 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 <sys/ioctl.h>
     27 #include <sys/types.h>
     28 #include <sys/stat.h>
     29 #include <fcntl.h>
     30 #include <unistd.h>
     31 #include "jni.h"
     32 #include "jni_util.h"
     33 #include "jlong.h"
     34 #include "io_util.h"
     35 #include "io_util_md.h"
     36 
     37 #include "jvm.h"
     38 
     39 
     40 #include <fcntl.h>
     41 #include <limits.h>
     42 
     43 #include "io_util_md.h"
     44 #include <nativehelper/JNIHelp.h>
     45 
     46 #define NATIVE_METHOD(className, functionName, signature) \
     47 { #functionName, signature, (void*)(className ## _ ## functionName) }
     48 
     49 /*******************************************************************/
     50 /*  BEGIN JNI ********* BEGIN JNI *********** BEGIN JNI ************/
     51 /*******************************************************************/
     52 
     53 jfieldID fis_fd; /* id for jobject 'fd' in java.io.FileInputStream */
     54 
     55 /**************************************************************
     56  * Input stream
     57  */
     58 
     59 
     60 static void FileInputStream_initIDs(JNIEnv *env) {
     61     jclass clazz = (*env)->FindClass(env, "java/io/FileInputStream");
     62     fis_fd = (*env)->GetFieldID(env, clazz, "fd", "Ljava/io/FileDescriptor;");
     63 }
     64 
     65 JNIEXPORT void JNICALL
     66 FileInputStream_open0(JNIEnv *env, jobject this, jstring path) {
     67     fileOpen(env, this, path, fis_fd, O_RDONLY);
     68 }
     69 
     70 JNIEXPORT jlong JNICALL
     71 FileInputStream_skip0(JNIEnv *env, jobject this, jlong toSkip) {
     72     jlong cur = jlong_zero;
     73     jlong end = jlong_zero;
     74     FD fd = GET_FD(this, fis_fd);
     75     if (fd == -1) {
     76         JNU_ThrowIOException (env, "Stream Closed");
     77         return 0;
     78     }
     79     if ((cur = IO_Lseek(fd, (jlong)0, (jint)SEEK_CUR)) == -1) {
     80       if (errno == ESPIPE) {
     81         JNU_ThrowByName(env, "java/io/FileInputStream$UseManualSkipException", NULL);
     82       } else {
     83         JNU_ThrowIOExceptionWithLastError(env, "Seek error");
     84       }
     85     } else if ((end = IO_Lseek(fd, toSkip, (jint)SEEK_CUR)) == -1) {
     86         JNU_ThrowIOExceptionWithLastError(env, "Seek error");
     87     }
     88     return (end - cur);
     89 }
     90 
     91 static int available(int fd, jlong *bytes) {
     92   int n;
     93   // Unlike the original OpenJdk implementation, we use FIONREAD for all file
     94   // types. For regular files, this is specified to return the difference
     95   // between the current position and the file size. Note that this can be
     96   // negative if we're positioned past the end of the file. We must return 0
     97   // in that case.
     98   if (ioctl(fd, FIONREAD, &n) != -1) {
     99     if (n < 0) {
    100       n = 0;
    101     }
    102     *bytes = n;
    103     return 1;
    104   }
    105 
    106   // FIONREAD is specified to return ENOTTY when fd refers to a file
    107   // type for which this ioctl isn't implemented.
    108   if (errno == ENOTTY) {
    109     *bytes = 0;
    110     return 1;
    111   }
    112 
    113   // Raise an exception for all other error types.
    114   return 0;
    115 }
    116 
    117 JNIEXPORT jint JNICALL
    118 FileInputStream_available0(JNIEnv *env, jobject this) {
    119     jlong ret;
    120     FD fd = GET_FD(this, fis_fd);
    121     if (fd == -1) {
    122         JNU_ThrowIOException (env, "Stream Closed");
    123         return 0;
    124     }
    125     if (available(fd, &ret)) {
    126         if (ret > INT_MAX) {
    127             ret = (jlong) INT_MAX;
    128         }
    129         return jlong_to_jint(ret);
    130     }
    131     JNU_ThrowIOExceptionWithLastError(env, NULL);
    132     return 0;
    133 }
    134 
    135 static JNINativeMethod gMethods[] = {
    136   NATIVE_METHOD(FileInputStream, open0, "(Ljava/lang/String;)V"),
    137   NATIVE_METHOD(FileInputStream, skip0, "(J)J"),
    138   NATIVE_METHOD(FileInputStream, available0, "()I"),
    139 };
    140 
    141 void register_java_io_FileInputStream(JNIEnv* env) {
    142     jniRegisterNativeMethods(env, "java/io/FileInputStream", gMethods, NELEM(gMethods));
    143     FileInputStream_initIDs(env);
    144 }
    145