src/java.base/share/classes/jdk/internal/jrtfs/JrtDirectoryStream.java

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  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 package jdk.internal.jrtfs;
  26 
  27 import java.nio.file.DirectoryStream;
  28 import java.nio.file.ClosedDirectoryStreamException;
  29 import java.nio.file.DirectoryIteratorException;
  30 import java.nio.file.NotDirectoryException;
  31 import java.nio.file.Path;
  32 import java.util.Iterator;

  33 import java.util.NoSuchElementException;
  34 import java.io.IOException;
  35 
  36 /**
  37  * DirectoryStream implementation for jrt file system implementations.
  38  *
  39  * @implNote This class needs to maintain JDK 8 source compatibility.
  40  *
  41  * It is used internally in the JDK to implement jimage/jrtfs access,
  42  * but also compiled and delivered as part of the jrtfs.jar to support access
  43  * to the jimage file provided by the shipped JDK by tools running on JDK 8.
  44  */
  45 final class JrtDirectoryStream implements DirectoryStream<Path> {
  46 
  47     private final AbstractJrtFileSystem jrtfs;
  48     private final AbstractJrtPath dir;
  49     private final DirectoryStream.Filter<? super Path> filter;
  50     private volatile boolean isClosed;
  51     private volatile Iterator<Path> itr;
  52 
  53     JrtDirectoryStream(AbstractJrtPath jrtPath,
  54             DirectoryStream.Filter<? super java.nio.file.Path> filter)
  55             throws IOException {
  56         this.jrtfs = jrtPath.getFileSystem();
  57         this.dir = jrtPath;
  58         // sanity check
  59         if (!jrtfs.isDirectory(dir, true)) {
  60             throw new NotDirectoryException(jrtPath.toString());
  61         }
  62 
  63         this.filter = filter;
  64     }
  65 
  66     @Override
  67     public synchronized Iterator<Path> iterator() {
  68         if (isClosed) {
  69             throw new ClosedDirectoryStreamException();
  70         }
  71         if (itr != null) {
  72             throw new IllegalStateException("Iterator has already been returned");
  73         }
  74 
  75         try {
  76             itr = jrtfs.iteratorOf(dir);
  77         } catch (IOException e) {
  78             throw new IllegalStateException(e);
  79         }
  80         return new Iterator<Path>() {
  81             /*
  82              * next Path value to return from this iterator.
  83              * null value means hasNext() not called yet
  84              * or last hasNext() returned false or resulted
  85              * in exception. If last hasNext() returned true,
  86              * then this field has non-null value.
  87              */
  88             private Path next;
  89 
  90             // get-and-clear and set-next by these methods
  91             private Path getAndClearNext() {
  92                 assert next != null;
  93                 Path result = this.next;
  94                 this.next = null;
  95                 return result;
  96             }
  97 
  98             private void setNext(Path path) {
  99                 assert path != null;
 100                 this.next = path;
 101             }
 102 
 103             // if hasNext() returns true, 'next' field has non-null Path
 104             @Override
 105             public synchronized boolean hasNext() {
 106                 if (next != null) {
 107                     return true;
 108                 }
 109 
 110                 if (isClosed) {
 111                     return false;
 112                 }
 113 
 114                 if (filter == null) {
 115                     if (itr.hasNext()) {
 116                         setNext(itr.next());
 117                         return true;
 118                     } else {
 119                         return false;
 120                     }
 121                 } else {
 122                     while (itr.hasNext()) {
 123                         Path tmpPath = itr.next();
 124                         try {
 125                             if (filter.accept(tmpPath)) {
 126                                 setNext(tmpPath);
 127                                 return true;
 128                             }
 129                         } catch (IOException ioe) {
 130                             throw new DirectoryIteratorException(ioe);
 131                         }
 132                     }
 133 
 134                     return false;
 135                 }
 136             }
 137 
 138             @Override
 139             public synchronized Path next() {
 140                 if (next != null) {
 141                     return getAndClearNext();
 142                 }
 143 
 144                 if (isClosed) {
 145                     throw new NoSuchElementException();
 146                 }
 147 
 148                 if (next == null && itr.hasNext()) {
 149                     // missing hasNext() between next() calls.
 150                     if (hasNext()) {
 151                         return getAndClearNext();
 152                     }
 153                 }
 154 
 155                 throw new NoSuchElementException();

 156             }
 157 
 158             @Override
 159             public void remove() {
 160                 throw new UnsupportedOperationException();
 161             }
 162         };
 163     }
 164 
 165     @Override
 166     public synchronized void close() throws IOException {
 167         isClosed = true;
 168     }
 169 }


  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 package jdk.internal.jrtfs;
  26 
  27 import java.nio.file.DirectoryStream;
  28 import java.nio.file.ClosedDirectoryStreamException;
  29 import java.nio.file.DirectoryIteratorException;
  30 import java.nio.file.NotDirectoryException;
  31 import java.nio.file.Path;
  32 import java.util.Iterator;
  33 import java.util.Objects;
  34 import java.util.NoSuchElementException;
  35 import java.io.IOException;
  36 
  37 /**
  38  * DirectoryStream implementation for jrt file system implementations.
  39  *
  40  * @implNote This class needs to maintain JDK 8 source compatibility.
  41  *
  42  * It is used internally in the JDK to implement jimage/jrtfs access,
  43  * but also compiled and delivered as part of the jrtfs.jar to support access
  44  * to the jimage file provided by the shipped JDK by tools running on JDK 8.
  45  */
  46 final class JrtDirectoryStream implements DirectoryStream<Path> {
  47 
  48     private final JrtPath dir;

  49     private final DirectoryStream.Filter<? super Path> filter;
  50     private volatile boolean isClosed;
  51     private volatile Iterator<Path> itr;
  52 
  53     JrtDirectoryStream(JrtPath dir,
  54             DirectoryStream.Filter<? super java.nio.file.Path> filter)
  55             throws IOException
  56     {
  57         this.dir = dir;
  58         if (!dir.jrtfs.isDirectory(dir, true)) {  // sanity check
  59             throw new NotDirectoryException(dir.toString());

  60         }

  61         this.filter = filter;
  62     }
  63 
  64     @Override
  65     public synchronized Iterator<Path> iterator() {
  66         if (isClosed)
  67             throw new ClosedDirectoryStreamException();
  68         if (itr != null)

  69             throw new IllegalStateException("Iterator has already been returned");


  70         try {
  71             itr = dir.jrtfs.iteratorOf(dir, filter);
  72         } catch (IOException e) {
  73             throw new IllegalStateException(e);
  74         }
  75         return new Iterator<Path>() {







  76             private Path next;















  77             @Override
  78             public synchronized boolean hasNext() {
  79                 if (isClosed)




  80                     return false;
  81                 return itr.hasNext();























  82             }
  83 
  84             @Override
  85             public synchronized Path next() {
  86                 if (isClosed)














  87                     throw new NoSuchElementException();
  88                 return itr.next();
  89             }
  90 
  91             @Override
  92             public void remove() {
  93                 throw new UnsupportedOperationException();
  94             }
  95         };
  96     }
  97 
  98     @Override
  99     public synchronized void close() throws IOException {
 100         isClosed = true;
 101     }
 102 }