FileInputStream.c revision cab01ac294bb8ded259851673baa4c6ca226f828 
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
53jfieldID fis_fd; /* id for jobject 'fd' in java.io.FileInputStream */
54
55/**************************************************************
56 * Input stream
57 */
58
59
60static 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
65JNIEXPORT void JNICALL
66FileInputStream_open0(JNIEnv *env, jobject this, jstring path) {
67    fileOpen(env, this, path, fis_fd, O_RDONLY);
68}
69
70JNIEXPORT jlong JNICALL
71FileInputStream_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
91static 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
117JNIEXPORT jint JNICALL
118FileInputStream_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
135static 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
141void register_java_io_FileInputStream(JNIEnv* env) {
142    jniRegisterNativeMethods(env, "java/io/FileInputStream", gMethods, NELEM(gMethods));
143    FileInputStream_initIDs(env);
144}
145