src/JAVA/libjafs/FileInputStream.c

   1 /*
   2  * Copyright (c) 2001-2002 International Business Machines Corp.
   3  * All rights reserved.
   4  *
   5  * This software has been released under the terms of the IBM Public
   6  * License.  For details, see the LICENSE file in the top-level source
   7  * directory or online at http://www.openafs.org/dl/license10.html
   8  *
   9  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  10  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  11  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  12  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR
  13  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  14  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  15  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  16  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  17  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  18  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  19  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  20  */
  21
  22 #include "Internal.h"
  23 #include "org_openafs_jafs_FileInputStream.h"
  24 #include <errno.h>
  25
  26 #include <fcntl.h>
  27
  28 #ifdef DMALLOC
  29 #include "dmalloc.h"
  30 #endif
  31
  32 /**
  33  * Be carefull with the memory management:
  34  *
  35  * - For every GetStringUTFChars call the corresponding ReleaseStringUTFChars.
  36  * - For every Get<type>ArrayElements call the corresponding
  37  *   Release<type>ArrayElements
  38  * - For every malloc call the corresponding free.
  39  */
  40
  41 /*-------------------------------------------------------------------------*/
  42
  43 /**
  44  * Opens an AFS file, with the specified name, for appending.
  45  *
  46  *  env         the Java environment
  47  *  obj         the current Java object
  48  *  fileNameUTF name of file to be opened
  49  *
  50  * @return              file descriptor
  51  * @exception   AFSFileException  if an I/O or other file related error occurs.
  52  */
  53 JNIEXPORT jint JNICALL Java_org_openafs_jafs_FileInputStream_openReadOnly
  54   (JNIEnv *env, jobject obj, jstring fileNameUTF)
  55 {
  56   int err;
  57   int fd = -1;          //file descriptor
  58
  59   fd = openAFSFile(env, fileNameUTF, O_RDONLY, 0, &err);
  60   if (fd < 0) {
  61     fprintf(stderr, "FileInputStream::openReadOnly(): err=%d\n", err);
  62     throwAFSFileException( env, err, NULL );
  63   }
  64   return fd;
  65 }
  66
  67 /**
  68  * Reads up to 'length' bytes of data from this input stream
  69  * into an array of bytes. This method blocks until some input is
  70  * available.
  71  *
  72  *  env         the Java environment
  73  *  obj         the current Java object
  74  *  jbytes              the data to be written
  75  *  offset              the start offset in the data
  76  *  length              the number of bytes that are written
  77  *
  78  * @return              the total number of bytes read into the buffer, or
  79  *                      <code>-1</code> if there is no more data because the end of
  80  *                      the file has been reached.
  81  * @exception   AFSFileException  if an I/O or other file related error occurs.
  82  */
  83 JNIEXPORT jint JNICALL Java_org_openafs_jafs_FileInputStream_read
  84   (JNIEnv *env, jobject obj, jbyteArray jbytes, jint offset, jint length)
  85 {
  86   int fd, bytesLen, bytesRead;
  87   jclass thisClass;
  88   jmethodID getFileDescriptorID;
  89   jbyte *bytes;
  90   jfieldID fid;
  91
  92   /* If we have to read 0 bytes just return */
  93   if(length == 0) return 0;
  94
  95   thisClass = (*env)->GetObjectClass(env, obj);
  96   fid = (*env)->GetFieldID(env, thisClass, "fileDescriptor", "I");
  97   fd = (*env)->GetIntField(env, obj, fid);
  98
  99   if(fd < 0) {
 100     fprintf(stderr, "FileInputStream::read(): invalid file state\n");
 101     throwAFSFileException(env, 0, "Invalid file state");
 102     return -1;
 103   }
 104
 105   bytes = (*env) -> GetByteArrayElements(env, jbytes, 0);
 106   bytesLen = (*env) -> GetArrayLength(env, jbytes);
 107   bytesRead = uafs_read(fd, bytes, bytesLen);
 108
 109   if (errno != 0) throwAFSFileException(env, errno, NULL);
 110
 111   (*env) -> ReleaseByteArrayElements(env, jbytes, bytes, 0);
 112   return (bytesRead > 0) ? bytesRead : -1;
 113 }
 114
 115 /**
 116  * Closes this file input stream and releases any system resources
 117  * associated with this stream. This file input stream may no longer
 118  * be used for writing bytes.
 119  *
 120  *  env         the Java environment
 121  *  obj         the current Java object
 122  *
 123  * @exception   AFSFileException  if an I/O or other file related error occurs.
 124  */
 125 JNIEXPORT void JNICALL Java_org_openafs_jafs_FileInputStream_close
 126   (JNIEnv *env, jobject obj)
 127 {
 128   int fd, rc;
 129   jclass thisClass;
 130   jmethodID getFileDescriptorID;
 131   jfieldID fid;
 132   char *bytes;
 133
 134   thisClass = (*env)->GetObjectClass(env, obj);
 135   fid = (*env)->GetFieldID(env, thisClass, "fileDescriptor", "I");
 136   fd = (*env)->GetIntField(env, obj, fid);
 137
 138   if(fd < 0) {
 139     fprintf(stderr, "FileInputStream::close(): invalid file state\n");
 140     throwAFSFileException(env, 0, "Invalid file state");
 141     return;
 142   }
 143
 144   rc = uafs_close(fd);
 145
 146   if (rc != 0) {
 147     throwAFSFileException(env, errno, NULL);
 148   }
 149 }
 150
 151
 152