1 files changed, 200 insertions, 0 deletions
diff --git a/netx/net/sourceforge/jnlp/util/lockingfile/LockingReaderWriter.java b/netx/net/sourceforge/jnlp/util/lockingfile/LockingReaderWriter.java
new file mode 100644
index 0000000..16fbaa6
--- /dev/null
+++ b/netx/net/sourceforge/jnlp/util/lockingfile/LockingReaderWriter.java
@@ -0,0 +1,200 @@
+/*
+Copyright (C) 2013 Red Hat, Inc.
+
+This file is part of IcedTea.
+
+IcedTea is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License as published by
+the Free Software Foundation, version 2.
+
+IcedTea is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with IcedTea; see the file COPYING.  If not, write to
+the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version.
+ */
+package net.sourceforge.jnlp.util.lockingfile;
+
+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.OutputStreamWriter;
+
+/**
+ * Process-locked string storage backed by a file.
+ * Each string is stored on its own line.
+ * Any new-lines must be encoded somehow if they are to be stored.
+ */
+public abstract class LockingReaderWriter {
+
+    private LockedFile lockedFile;
+
+    /**
+     * Create locking file-backed storage.
+     * @param file the storage file
+     */
+    public LockingReaderWriter(File file) {
+        this.lockedFile = LockedFile.getInstance(file);
+    }
+
+    /**
+     * Get the underlying file. 
+     * Any access to this file should use lock() & unlock().
+     * 
+     * @return the file
+     */
+    public File getBackingFile() {
+        return this.lockedFile.getFile();
+    }
+
+    public boolean isReadOnly() {
+        return this.lockedFile.isReadOnly();
+    }
+
+    /**
+     * Lock the underlying storage. Lock is reentrant.
+     */
+    public void lock() {
+        try {
+            lockedFile.lock();
+        } catch (IOException e) {
+            throw new StorageIoException(e);
+        }
+    }
+
+    /**
+     * Unlock the underlying storage. Lock is reentrant.
+     */
+    public void unlock() {
+        try {
+            lockedFile.unlock();
+        } catch (IOException e) {
+            throw new StorageIoException(e);
+        }
+    }
+
+    /**
+     * Writes stored contents to file. Assumes lock is held.
+     * @throws IOException
+     */
+    protected void writeContents() throws IOException {
+        if (!getBackingFile().isFile()){
+            return;
+        }
+        if (isReadOnly()){
+            return;
+        }
+        BufferedWriter writer = null;
+        try {
+            writer = new BufferedWriter(new OutputStreamWriter(
+                    new FileOutputStream(getBackingFile()), "UTF-8"));
+            writeContent(writer);
+            writer.flush();
+        } finally {
+            if (writer != null) {
+                writer.close();
+            }
+        }
+    }
+
+    protected abstract void writeContent(BufferedWriter writer) throws IOException;
+
+    /**
+     * Reads contents from file. Assumes lock is held.
+     * @throws IOException
+     */
+    protected void readContents() throws IOException {
+        if (!getBackingFile().isFile()){
+            return;
+        }
+        BufferedReader reader = null;
+        try {
+            reader = new BufferedReader(new InputStreamReader(
+                    new FileInputStream(getBackingFile()), "UTF-8"));
+
+            while (true) {
+                String line = reader.readLine();
+                if (line == null) {
+                    break;
+                }
+                readLine(line);
+            }
+        } finally {
+            if (reader != null) {
+                reader.close();
+            }
+        }
+    }
+
+    /**
+     * Reads contents from the file, first acquring a lock.
+     * @throws IOException
+     */
+    protected synchronized void readContentsLocked() throws IOException {
+        doLocked(new Runnable() {
+
+            @Override
+            public void run() {
+                try {
+                    readContents();
+                } catch (IOException ex) {
+                    throw new StorageIoException(ex);
+                }
+            }
+        });
+    }
+
+    /**
+     * Write contents to the file, first acquring a lock.
+     * @throws IOException
+     */
+    protected synchronized void writeContentsLocked() throws IOException {
+        doLocked(new Runnable() {
+
+            public void run() {
+                try {
+                    writeContents();
+                } catch (IOException ex) {
+                    throw new StorageIoException(ex);
+                }
+            }
+        });
+
+    }
+
+    protected void doLocked(Runnable r) {
+        lock();
+        try {
+            r.run();
+        } finally {
+            unlock();
+        }
+    }
+
+    protected abstract void readLine(String line);
+}