/*
 
* Copyright (c) 1998, 2013, Oracle and/or its affiliates. All rights reserved.
 
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 
*
 
* This code is free software; you can redistribute it and/or modify it
 
* under the terms of the GNU General Public License version 2 only, as
 
* published by the Free Software Foundation.
  
Oracle designates this
 
* particular file as subject to the "Classpath" exception as provided
 
* by Oracle in the LICENSE file that accompanied this code.
 
*
 
* This code 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
 
* version 2 for more details (a copy is included in the LICENSE file that
 
* accompanied this code).
 
*
 
* You should have received a copy of the GNU General Public License version
 
* 2 along with this work; if not, write to the Free Software Foundation,
 
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 
*
 
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 
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*/

package java.io;

import java.lang.annotation.Native;

/**
 
* Package-private abstract class for the local filesystem abstraction.
 
*/


abstract class FileSystem {

    
/* -- Normalization and construction -- */

    
/**
     
* Return the local filesystem's name-separator character.
     
*/

    
public abstract char getSeparator();

    
/**
     
* Return the local filesystem's path-separator character.
     
*/

    
public abstract char getPathSeparator();

    
/**
     
* Convert the given pathname string to normal form.
  
If the string is
     
* already in normal form then it is simply returned.
     
*/

    
public abstract String normalize(String path);

    
/**
     
* Compute the length of this pathname string's prefix.
  
The pathname
     
* string must be in normal form.
     
*/

    
public abstract int prefixLength(String path);

    
/**
     
* Resolve the child pathname string against the parent.
     
* Both strings must be in normal form, and the result
     
* will be in normal form.
     
*/

    
public abstract String resolve(String parent, String child);

    
/**
     
* Return the parent pathname string to be used when the parent-directory
     
* argument in one of the two-argument File constructors is the empty
     
* pathname.
     
*/

    
public abstract String getDefaultParent();

    
/**
     
* Post-process the given URI path string if necessary.
  
This is used on
     
* win32, e.g., to transform "/c:/foo" into "c:/foo".
  
The path string
     
* still has slash separators; code in the File class will translate them
     
* after this method returns.
     
*/

    
public abstract String fromURIPath(String path);


    
/* -- Path operations -- */

    
/**
     
* Tell whether or not the given abstract pathname is absolute.
     
*/

    
public abstract boolean isAbsolute(File f);

    
/**
     
* Resolve the given abstract pathname into absolute form.
  
Invoked by the
     
* getAbsolutePath and getCanonicalPath methods in the File class.
     
*/

    
public abstract String resolve(File f);

    
public abstract String canonicalize(String path) throws IOException;


    
/* -- Attribute accessors -- */

    
/* Constants for simple boolean attributes */
    
@Native public static final int BA_EXISTS
    
= 0x01;
    
@Native public static final int BA_REGULAR
   
= 0x02;
    
@Native public static final int BA_DIRECTORY = 0x04;
    
@Native public static final int BA_HIDDEN
    
= 0x08;

    
/**
     
* Return the simple boolean attributes for the file or directory denoted
     
* by the given abstract pathname, or zero if it does not exist or some
     
* other I/O error occurs.
     
*/

    
public abstract int getBooleanAttributes(File f);

    
@Native public static final int ACCESS_READ
    
= 0x04;
    
@Native public static final int ACCESS_WRITE
   
= 0x02;
    
@Native public static final int ACCESS_EXECUTE = 0x01;

    
/**
     
* Check whether the file or directory denoted by the given abstract
     
* pathname may be accessed by this process.
  
The second argument specifies
     
* which access, ACCESS_READ, ACCESS_WRITE or ACCESS_EXECUTE, to check.
     
* Return false if access is denied or an I/O error occurs
     
*/

    
public abstract boolean checkAccess(File f, int access);
    
/**
     
* Set on or off the access permission (to owner only or to all) to the file
     
* or directory denoted by the given abstract pathname, based on the parameters
     
* enable, access and oweronly.
     
*/

    
public abstract boolean setPermission(File f, int access, boolean enable, boolean owneronly);

    
/**
     
* Return the time at which the file or directory denoted by the given
     
* abstract pathname was last modified, or zero if it does not exist or
     
* some other I/O error occurs.
     
*/

    
public abstract long getLastModifiedTime(File f);

    
/**
     
* Return the length in bytes of the file denoted by the given abstract
     
* pathname, or zero if it does not exist, is a directory, or some other
     
* I/O error occurs.
     
*/

    
public abstract long getLength(File f);


    
/* -- File operations -- */

    
/**
     
* Create a new empty file with the given pathname.
  
Return
     
* <code>true</code> if the file was created and <code>false</code> if a
     
* file or directory with the given pathname already exists.
  
Throw an
     
* IOException if an I/O error occurs.
     
*/

    
public abstract boolean createFileExclusively(String pathname)
        
throws IOException;

    
/**
     
* Delete the file or directory denoted by the given abstract pathname,
     
* returning <code>true</code> if and only if the operation succeeds.
     
*/

    
public abstract boolean delete(File f);

    
/**
     
* List the elements of the directory denoted by the given abstract
     
* pathname.
  
Return an array of strings naming the elements of the
     
* directory if successful; otherwise, return <code>null</code>.
     
*/

    
public abstract String[] list(File f);

    
/**
     
* Create a new directory denoted by the given abstract pathname,
     
* returning <code>true</code> if and only if the operation succeeds.
     
*/

    
public abstract boolean createDirectory(File f);

    
/**
     
* Rename the file or directory denoted by the first abstract pathname to
     
* the second abstract pathname, returning <code>true</code> if and only if
     
* the operation succeeds.
     
*/

    
public abstract boolean rename(File f1, File f2);

    
/**
     
* Set the last-modified time of the file or directory denoted by the
     
* given abstract pathname, returning <code>true</code> if and only if the
     
* operation succeeds.
     
*/

    
public abstract boolean setLastModifiedTime(File f, long time);

    
/**
     
* Mark the file or directory denoted by the given abstract pathname as
     
* read-only, returning <code>true</code> if and only if the operation
     
* succeeds.
     
*/

    
public abstract boolean setReadOnly(File f);


    
/* -- Filesystem interface -- */

    
/**
     
* List the available filesystem roots.
     
*/
    
public abstract File[] listRoots();

    
/* -- Disk usage -- */
    
@Native public static final int SPACE_TOTAL
  
= 0;
    
@Native public static final int SPACE_FREE
   
= 1;
    
@Native public static final int SPACE_USABLE = 2;

    
public abstract long getSpace(File f, int t);

    
/* -- Basic infrastructure -- */

    
/**
     
* Compare two abstract pathnames lexicographically.
     
*/
    
public abstract int compare(File f1, File f2);

    
/**
     
* Compute the hash code of an abstract pathname.
     
*/
    
public abstract int hashCode(File f);

    
// Flags for enabling/disabling performance optimizations for file
    
// name canonicalization
    
static boolean useCanonCaches
      
= true;
    
static boolean useCanonPrefixCache = true;

    
private static boolean getBooleanProperty(String prop, boolean defaultVal) {
        
String val = System.getProperty(prop);
        
if (val == null) return defaultVal;
        
if (val.equalsIgnoreCase("true")) {
            
return true;
        
} else {
            
return false;
        
}
    
}

    
static {
        
useCanonCaches
      
= getBooleanProperty("sun.io.useCanonCaches",
                                                 
useCanonCaches);
        
useCanonPrefixCache = getBooleanProperty("sun.io.useCanonPrefixCache",
                                                 
useCanonPrefixCache);
    
}
}