1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 #define LOG_TAG "File"
19
20 #include "JNIHelp.h"
21 #include "JniConstants.h"
22 #include "JniException.h"
23 #include "ScopedPrimitiveArray.h"
24 #include "ScopedUtfChars.h"
25 #include "readlink.h"
26 #include "toStringArray.h"
27
28 #include <string>
29 #include <vector>
30
31 #include <dirent.h>
32 #include <errno.h>
33 #include <fcntl.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <sys/stat.h>
37 #include <sys/types.h>
38 #include <sys/vfs.h>
39 #include <time.h>
40 #include <unistd.h>
41 #include <utime.h>
42
File_readlink(JNIEnv * env,jclass,jstring javaPath)43 static jstring File_readlink(JNIEnv* env, jclass, jstring javaPath) {
44 ScopedUtfChars path(env, javaPath);
45 if (path.c_str() == NULL) {
46 return NULL;
47 }
48
49 std::string result;
50 if (!readlink(path.c_str(), result)) {
51 jniThrowIOException(env, errno);
52 return NULL;
53 }
54 return env->NewStringUTF(result.c_str());
55 }
56
File_realpath(JNIEnv * env,jclass,jstring javaPath)57 static jstring File_realpath(JNIEnv* env, jclass, jstring javaPath) {
58 ScopedUtfChars path(env, javaPath);
59 if (path.c_str() == NULL) {
60 return NULL;
61 }
62
63 extern bool realpath(const char* path, std::string& resolved);
64 std::string result;
65 if (!realpath(path.c_str(), result)) {
66 jniThrowIOException(env, errno);
67 return NULL;
68 }
69 return env->NewStringUTF(result.c_str());
70 }
71
File_setLastModifiedImpl(JNIEnv * env,jclass,jstring javaPath,jlong ms)72 static jboolean File_setLastModifiedImpl(JNIEnv* env, jclass, jstring javaPath, jlong ms) {
73 ScopedUtfChars path(env, javaPath);
74 if (path.c_str() == NULL) {
75 return JNI_FALSE;
76 }
77
78 // We want to preserve the access time.
79 struct stat sb;
80 if (stat(path.c_str(), &sb) == -1) {
81 return JNI_FALSE;
82 }
83
84 // TODO: we could get microsecond resolution with utimes(3), "legacy" though it is.
85 utimbuf times;
86 times.actime = sb.st_atime;
87 times.modtime = static_cast<time_t>(ms / 1000);
88 return (utime(path.c_str(), ×) == 0);
89 }
90
91 // Iterates over the filenames in the given directory.
92 class ScopedReaddir {
93 public:
ScopedReaddir(const char * path)94 ScopedReaddir(const char* path) {
95 mDirStream = opendir(path);
96 mIsBad = (mDirStream == NULL);
97 }
98
~ScopedReaddir()99 ~ScopedReaddir() {
100 if (mDirStream != NULL) {
101 closedir(mDirStream);
102 }
103 }
104
105 // Returns the next filename, or NULL.
next()106 const char* next() {
107 if (mIsBad) {
108 return NULL;
109 }
110 dirent* result = NULL;
111 int rc = readdir_r(mDirStream, &mEntry, &result);
112 if (rc != 0) {
113 mIsBad = true;
114 return NULL;
115 }
116 return (result != NULL) ? result->d_name : NULL;
117 }
118
119 // Has an error occurred on this stream?
isBad() const120 bool isBad() const {
121 return mIsBad;
122 }
123
124 private:
125 DIR* mDirStream;
126 dirent mEntry;
127 bool mIsBad;
128
129 // Disallow copy and assignment.
130 ScopedReaddir(const ScopedReaddir&);
131 void operator=(const ScopedReaddir&);
132 };
133
134 typedef std::vector<std::string> DirEntries;
135
136 // Reads the directory referred to by 'pathBytes', adding each directory entry
137 // to 'entries'.
readDirectory(JNIEnv * env,jstring javaPath,DirEntries & entries)138 static bool readDirectory(JNIEnv* env, jstring javaPath, DirEntries& entries) {
139 ScopedUtfChars path(env, javaPath);
140 if (path.c_str() == NULL) {
141 return false;
142 }
143
144 ScopedReaddir dir(path.c_str());
145 const char* filename;
146 while ((filename = dir.next()) != NULL) {
147 if (strcmp(filename, ".") != 0 && strcmp(filename, "..") != 0) {
148 // TODO: this hides allocation failures from us. Push directory iteration up into Java?
149 entries.push_back(filename);
150 }
151 }
152 return !dir.isBad();
153 }
154
File_listImpl(JNIEnv * env,jclass,jstring javaPath)155 static jobjectArray File_listImpl(JNIEnv* env, jclass, jstring javaPath) {
156 // Read the directory entries into an intermediate form.
157 DirEntries entries;
158 if (!readDirectory(env, javaPath, entries)) {
159 return NULL;
160 }
161 // Translate the intermediate form into a Java String[].
162 return toStringArray(env, entries);
163 }
164
165 static JNINativeMethod gMethods[] = {
166 NATIVE_METHOD(File, listImpl, "(Ljava/lang/String;)[Ljava/lang/String;"),
167 NATIVE_METHOD(File, readlink, "(Ljava/lang/String;)Ljava/lang/String;"),
168 NATIVE_METHOD(File, realpath, "(Ljava/lang/String;)Ljava/lang/String;"),
169 NATIVE_METHOD(File, setLastModifiedImpl, "(Ljava/lang/String;J)Z"),
170 };
register_java_io_File(JNIEnv * env)171 void register_java_io_File(JNIEnv* env) {
172 jniRegisterNativeMethods(env, "java/io/File", gMethods, NELEM(gMethods));
173 }
174