Moving to root below branch label

git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@2005 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/filesys/locking/FileLock.java

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+/*
+ * Copyright (C) 2005 Alfresco, Inc.
+ *
+ * Licensed under the Mozilla Public License version 1.1 
+ * with a permitted attribution clause. You may obtain a
+ * copy of the License at
+ *
+ *   http://www.alfresco.org/legal/license.txt
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific
+ * language governing permissions and limitations under the
+ * License.
+ */
+package org.alfresco.filesys.locking;
+
+/**
+ * File Lock Class
+ * <p>
+ * Contains the details of a single file lock.
+ */
+public class FileLock
+{
+
+    // Constants
+
+    public static final long LockWholeFile = 0xFFFFFFFFFFFFFFFFL;
+
+    // Start lock offset and length
+
+    private long m_offset;
+    private long m_length;
+
+    // Owner process id
+
+    private int m_pid;
+
+    /**
+     * Class constructor
+     * 
+     * @param offset long
+     * @param len long
+     * @param pid int
+     */
+    public FileLock(long offset, long len, int pid)
+    {
+        setOffset(offset);
+        setLength(len);
+        setProcessId(pid);
+    }
+
+    /**
+     * Get the starting lock offset
+     * 
+     * @return long Starting lock offset.
+     */
+    public final long getOffset()
+    {
+        return m_offset;
+    }
+
+    /**
+     * Set the starting lock offset.
+     * 
+     * @param long Starting lock offset
+     */
+    public final void setOffset(long offset)
+    {
+        m_offset = offset;
+    }
+
+    /**
+     * Get the locked section length
+     * 
+     * @return long Locked section length
+     */
+    public final long getLength()
+    {
+        return m_length;
+    }
+
+    /**
+     * Set the locked section length
+     * 
+     * @param long Locked section length
+     */
+    public final void setLength(long len)
+    {
+        if (len < 0)
+            m_length = LockWholeFile;
+        else
+            m_length = len;
+    }
+
+    /**
+     * Get the owner process id for the lock
+     * 
+     * @return int
+     */
+    public final int getProcessId()
+    {
+        return m_pid;
+    }
+
+    /**
+     * Deterine if the lock is locking the whole file
+     * 
+     * @return boolean
+     */
+    public final boolean isWholeFile()
+    {
+        return m_length == LockWholeFile ? true : false;
+    }
+
+    /**
+     * Set the process id of the owner of this lock
+     * 
+     * @param pid int
+     */
+    public final void setProcessId(int pid)
+    {
+        m_pid = pid;
+    }
+
+    /**
+     * Check if the specified locks byte range overlaps this locks byte range.
+     * 
+     * @param lock FileLock
+     */
+    public final boolean hasOverlap(FileLock lock)
+    {
+        return hasOverlap(lock.getOffset(), lock.getLength());
+    }
+
+    /**
+     * Check if the specified locks byte range overlaps this locks byte range.
+     * 
+     * @param offset long
+     * @param len long
+     */
+    public final boolean hasOverlap(long offset, long len)
+    {
+
+        // Check if the lock is for the whole file
+
+        if (isWholeFile())
+            return true;
+
+        // Check if the locks overlap
+
+        long endOff = getOffset() + getLength();
+
+        if (getOffset() < offset && endOff < offset)
+            return false;
+
+        endOff = offset + len;
+
+        if (getOffset() > endOff)
+            return false;
+
+        // Locks overlap
+
+        return true;
+    }
+
+    /**
+     * Return the lock details as a string
+     * 
+     * @return String
+     */
+    public String toString()
+    {
+        StringBuffer str = new StringBuffer();
+
+        str.append("[PID=");
+        str.append(getProcessId());
+        str.append(",Offset=");
+        str.append(getOffset());
+        str.append(",Len=");
+        str.append(getLength());
+        str.append("]");
+
+        return str.toString();
+    }
+}

source/java/org/alfresco/filesys/locking/FileLockException.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2005 Alfresco, Inc.
+ *
+ * Licensed under the Mozilla Public License version 1.1 
+ * with a permitted attribution clause. You may obtain a
+ * copy of the License at
+ *
+ *   http://www.alfresco.org/legal/license.txt
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific
+ * language governing permissions and limitations under the
+ * License.
+ */
+package org.alfresco.filesys.locking;
+
+import java.io.IOException;
+
+/**
+ * File Lock Exception Class
+ */
+public class FileLockException extends IOException
+{
+    private static final long serialVersionUID = 3257845472092893751L;
+
+    /**
+     * Class constructor.
+     */
+    public FileLockException()
+    {
+        super();
+    }
+
+    /**
+     * Class constructor.
+     * 
+     * @param s java.lang.String
+     */
+    public FileLockException(String s)
+    {
+        super(s);
+    }
+}

source/java/org/alfresco/filesys/locking/FileLockList.java

@@ -0,0 +1,246 @@
+/*
+ * Copyright (C) 2005 Alfresco, Inc.
+ *
+ * Licensed under the Mozilla Public License version 1.1 
+ * with a permitted attribution clause. You may obtain a
+ * copy of the License at
+ *
+ *   http://www.alfresco.org/legal/license.txt
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific
+ * language governing permissions and limitations under the
+ * License.
+ */
+package org.alfresco.filesys.locking;
+
+import java.util.Vector;
+
+/**
+ * File Lock List Class
+ * <p>
+ * Contains a list of the current locks on a file.
+ */
+public class FileLockList
+{
+
+    // List of file locks
+
+    private Vector<FileLock> m_lockList;
+
+    /**
+     * Construct an empty file lock list.
+     */
+    public FileLockList()
+    {
+        m_lockList = new Vector<FileLock>();
+    }
+
+    /**
+     * Add a lock to the list
+     * 
+     * @param lock Lock to be added to the list.
+     */
+    public final void addLock(FileLock lock)
+    {
+        m_lockList.add(lock);
+    }
+
+    /**
+     * Remove a lock from the list
+     * 
+     * @param lock FileLock
+     * @return FileLock
+     */
+    public final FileLock removeLock(FileLock lock)
+    {
+        return removeLock(lock.getOffset(), lock.getLength(), lock.getProcessId());
+    }
+
+    /**
+     * Remove a lock from the list
+     * 
+     * @param long offset Starting offset of the lock
+     * @param long len Locked section length
+     * @param int pid Owner process id
+     * @return FileLock
+     */
+    public final FileLock removeLock(long offset, long len, int pid)
+    {
+
+        // Check if there are any locks in the list
+
+        if (numberOfLocks() == 0)
+            return null;
+
+        // Search for the required lock
+
+        for (int i = 0; i < numberOfLocks(); i++)
+        {
+
+            // Get the current lock details
+
+            FileLock curLock = getLockAt(i);
+            if (curLock.getOffset() == offset && curLock.getLength() == len && curLock.getProcessId() == pid)
+            {
+
+                // Remove the lock from the list
+
+                m_lockList.removeElementAt(i);
+                return curLock;
+            }
+        }
+
+        // Lock not found
+
+        return null;
+    }
+
+    /**
+     * Remove all locks from the list
+     */
+    public final void removeAllLocks()
+    {
+        m_lockList.removeAllElements();
+    }
+
+    /**
+     * Return the specified lock details
+     * 
+     * @param int Lock index
+     * @return FileLock
+     */
+    public final FileLock getLockAt(int idx)
+    {
+        if (idx < m_lockList.size())
+            return m_lockList.elementAt(idx);
+        return null;
+    }
+
+    /**
+     * Check if the new lock should be allowed by comparing with the locks in the list.
+     * 
+     * @param lock FileLock
+     * @return boolean true if the lock can be granted, else false.
+     */
+    public final boolean allowsLock(FileLock lock)
+    {
+
+        // If the list is empty we can allow the lock request
+
+        if (numberOfLocks() == 0)
+            return true;
+
+        // Search for any overlapping locks
+
+        for (int i = 0; i < numberOfLocks(); i++)
+        {
+
+            // Get the current lock details
+
+            FileLock curLock = getLockAt(i);
+            if (curLock.hasOverlap(lock))
+                return false;
+        }
+
+        // The lock does not overlap with any existing locks
+
+        return true;
+    }
+
+    /**
+     * Check if the file is readable for the specified section of the file and process id
+     * 
+     * @param offset long
+     * @param len long
+     * @param pid int
+     * @return boolean
+     */
+    public final boolean canReadFile(long offset, long len, int pid)
+    {
+
+        // If the list is empty we can allow the read request
+
+        if (numberOfLocks() == 0)
+            return true;
+
+        // Search for a lock that prevents the read
+
+        for (int i = 0; i < numberOfLocks(); i++)
+        {
+
+            // Get the current lock details
+
+            FileLock curLock = getLockAt(i);
+
+            // Check if the process owns the lock, if not then check if there is an overlap
+
+            if (curLock.getProcessId() != pid)
+            {
+
+                // Check if the read overlaps with the locked area
+
+                if (curLock.hasOverlap(offset, len) == true)
+                    return false;
+            }
+        }
+
+        // The lock does not overlap with any existing locks
+
+        return true;
+    }
+
+    /**
+     * Check if the file is writeable for the specified section of the file and process id
+     * 
+     * @param offset long
+     * @param len long
+     * @param pid int
+     * @return boolean
+     */
+    public final boolean canWriteFile(long offset, long len, int pid)
+    {
+
+        // If the list is empty we can allow the read request
+
+        if (numberOfLocks() == 0)
+            return true;
+
+        // Search for a lock that prevents the read
+
+        for (int i = 0; i < numberOfLocks(); i++)
+        {
+
+            // Get the current lock details
+
+            FileLock curLock = getLockAt(i);
+
+            // Check if the process owns the lock, if not then check if there is an overlap
+
+            if (curLock.getProcessId() != pid)
+            {
+
+                // Check if the read overlaps with the locked area
+
+                if (curLock.hasOverlap(offset, len) == true)
+                    return false;
+            }
+        }
+
+        // The lock does not overlap with any existing locks
+
+        return true;
+    }
+
+    /**
+     * Return the count of locks in the list.
+     * 
+     * @return int Number of locks in the list.
+     */
+    public final int numberOfLocks()
+    {
+        return m_lockList.size();
+    }
+}

source/java/org/alfresco/filesys/locking/FileUnlockException.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2005 Alfresco, Inc.
+ *
+ * Licensed under the Mozilla Public License version 1.1 
+ * with a permitted attribution clause. You may obtain a
+ * copy of the License at
+ *
+ *   http://www.alfresco.org/legal/license.txt
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific
+ * language governing permissions and limitations under the
+ * License.
+ */
+package org.alfresco.filesys.locking;
+
+import java.io.IOException;
+
+/**
+ * File Unlock Exception Class
+ */
+public class FileUnlockException extends IOException
+{
+    private static final long serialVersionUID = 3257290240262484786L;
+
+    /**
+     * Class constructor.
+     */
+    public FileUnlockException()
+    {
+        super();
+    }
+
+    /**
+     * Class constructor.
+     * 
+     * @param s java.lang.String
+     */
+    public FileUnlockException(String s)
+    {
+        super(s);
+    }
+}

source/java/org/alfresco/filesys/locking/LockConflictException.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2005 Alfresco, Inc.
+ *
+ * Licensed under the Mozilla Public License version 1.1 
+ * with a permitted attribution clause. You may obtain a
+ * copy of the License at
+ *
+ *   http://www.alfresco.org/legal/license.txt
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific
+ * language governing permissions and limitations under the
+ * License.
+ */
+package org.alfresco.filesys.locking;
+
+import java.io.IOException;
+
+/**
+ * Lock Conflict Exception Class
+ * <p>
+ * Thrown when a lock request overlaps with an existing lock on a file.
+ */
+public class LockConflictException extends IOException
+{
+
+    // Serializable version id
+
+    private static final long serialVersionUID = 0;
+
+    /**
+     * Class constructor.
+     */
+    public LockConflictException()
+    {
+        super();
+    }
+
+    /**
+     * Class constructor.
+     * 
+     * @param s java.lang.String
+     */
+    public LockConflictException(String s)
+    {
+        super(s);
+    }
+}

source/java/org/alfresco/filesys/locking/NotLockedException.java

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+/*
+ * Copyright (C) 2005 Alfresco, Inc.
+ *
+ * Licensed under the Mozilla Public License version 1.1 
+ * with a permitted attribution clause. You may obtain a
+ * copy of the License at
+ *
+ *   http://www.alfresco.org/legal/license.txt
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific
+ * language governing permissions and limitations under the
+ * License.
+ */
+package org.alfresco.filesys.locking;
+
+import java.io.IOException;
+
+/**
+ * Not Locked Exception Class
+ * <p>
+ * Thrown when an unlock request is received that has not active lock on a file.
+ */
+public class NotLockedException extends IOException
+{
+    private static final long serialVersionUID = 3834594296543261488L;
+
+    /**
+     * Class constructor.
+     */
+    public NotLockedException()
+    {
+        super();
+    }
+
+    /**
+     * Class constructor.
+     * 
+     * @param s java.lang.String
+     */
+    public NotLockedException(String s)
+    {
+        super(s);
+    }
+}