1 /*
2  * Copyright (c) 1997, 2010, 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 "jni.h"
27 #include "jni_util.h"
28 
29 extern jfieldID IO_fd_fdID;
30 extern jfieldID IO_handle_fdID;
31 
32 #ifdef _ALLBSD_SOURCE
33 #include <fcntl.h>
34 #ifndef O_SYNC
35 #define O_SYNC  O_FSYNC
36 #endif
37 #ifndef O_DSYNC
38 #define O_DSYNC O_FSYNC
39 #endif
40 #elif !defined(O_DSYNC) || !defined(O_SYNC)
41 #define O_SYNC  (0x0800)
42 #define O_DSYNC (0x2000)
43 #endif
44 
45 /*
46  * IO helper functions
47  */
48 
49 jint readSingle(JNIEnv *env, jobject this, jfieldID fid);
50 jint readBytes(JNIEnv *env, jobject this, jbyteArray bytes, jint off,
51                jint len, jfieldID fid);
52 void writeSingle(JNIEnv *env, jobject this, jint byte, jboolean append, jfieldID fid);
53 void writeBytes(JNIEnv *env, jobject this, jbyteArray bytes, jint off,
54                 jint len, jboolean append, jfieldID fid);
55 void fileOpen(JNIEnv *env, jobject this, jstring path, jfieldID fid, int flags);
56 void throwFileNotFoundException(JNIEnv *env, jstring path);
57 
58 
59 /*
60  * Macros for managing platform strings.  The typical usage pattern is:
61  *
62  *     WITH_PLATFORM_STRING(env, string, var) {
63  *         doSomethingWith(var);
64  *     } END_PLATFORM_STRING(env, var);
65  *
66  *  where  env      is the prevailing JNIEnv,
67  *         string   is a JNI reference to a java.lang.String object, and
68  *         var      is the char * variable that will point to the string,
69  *                  after being converted into the platform encoding.
70  *
71  * The related macro WITH_FIELD_PLATFORM_STRING first extracts the string from
72  * a given field of a given object:
73  *
74  *     WITH_FIELD_PLATFORM_STRING(env, object, id, var) {
75  *         doSomethingWith(var);
76  *     } END_PLATFORM_STRING(env, var);
77  *
78  *  where  env      is the prevailing JNIEnv,
79  *         object   is a jobject,
80  *         id       is the field ID of the String field to be extracted, and
81  *         var      is the char * variable that will point to the string.
82  *
83  * Uses of these macros may be nested as long as each WITH_.._STRING macro
84  * declares a unique variable.
85  */
86 
87 #define WITH_PLATFORM_STRING(env, strexp, var)                                \
88     if (1) {                                                                  \
89         const char *var;                                                      \
90         jstring _##var##str = (strexp);                                       \
91         if (_##var##str == NULL) {                                            \
92             JNU_ThrowNullPointerException((env), NULL);                       \
93             goto _##var##end;                                                 \
94         }                                                                     \
95         var = JNU_GetStringPlatformChars((env), _##var##str, NULL);           \
96         if (var == NULL) goto _##var##end;
97 
98 #define WITH_FIELD_PLATFORM_STRING(env, object, id, var)                      \
99     WITH_PLATFORM_STRING(env,                                                 \
100                          ((object == NULL)                                    \
101                           ? NULL                                              \
102                           : (*(env))->GetObjectField((env), (object), (id))), \
103                          var)
104 
105 #define END_PLATFORM_STRING(env, var)                                         \
106         JNU_ReleaseStringPlatformChars(env, _##var##str, var);                \
107     _##var##end: ;                                                            \
108     } else ((void)NULL)
109 
110 
111 /* Macros for transforming Java Strings into native Unicode strings.
112  * Works analogously to WITH_PLATFORM_STRING.
113  */
114 
115 #define WITH_UNICODE_STRING(env, strexp, var)                                 \
116     if (1) {                                                                  \
117         const jchar *var;                                                     \
118         jstring _##var##str = (strexp);                                       \
119         if (_##var##str == NULL) {                                            \
120             JNU_ThrowNullPointerException((env), NULL);                       \
121             goto _##var##end;                                                 \
122         }                                                                     \
123         var = (*(env))->GetStringChars((env), _##var##str, NULL);             \
124         if (var == NULL) goto _##var##end;
125 
126 #define END_UNICODE_STRING(env, var)                                          \
127         (*(env))->ReleaseStringChars(env, _##var##str, var);                  \
128     _##var##end: ;                                                            \
129     } else ((void)NULL)
130