src/main/java/com/google/devtools/build/lib/windows/WindowsFileOperations.java - bazel - Git at Google

 // Copyright 2016 The Bazel Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //    http://www.apache.org/licenses/LICENSE-2.0
 //
 // 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 com.google.devtools.build.lib.windows;

 import com.google.devtools.build.lib.jni.JniLoader;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.nio.file.AccessDeniedException;

 /** File operations on Windows. */
 public class WindowsFileOperations {

   // A note about UNC paths and path prefixes on Windows. The prefixes can be:
   // - "\\?\", meaning it's a UNC path that is passed to user mode unicode WinAPI functions
   //   (e.g. CreateFileW) or a return value of theirs (e.g. GetLongPathNameW); this is the
   //   prefix we'll most often see
   // - "\??\", meaning it's Device Object path; it's mostly only used by kernel/driver functions
   //   but we may come across it when resolving junction targets, as the target's path is
   //   specified with this prefix, see usages of DeviceIoControl with FSCTL_GET_REPARSE_POINT
   // - "\\.\", meaning it's a Device Object path again; both "\??\" and "\\.\" are shorthands
   //   for the "\DosDevices\" Object Directory, so "\\.\C:" and "\??\C:" and "\DosDevices\C:"
   //   and "C:\" all mean the same thing, but functions like CreateFileW don't understand the
   //   fully qualified device path, only the shorthand versions; the difference between "\\.\"
   //   is "\??\" is not entirely clear (one is not available while Windows is booting, but
   //   that only concerns device drivers) but we most likely won't come across them anyway
   // Some of this is documented here:
   // - https://msdn.microsoft.com/en-us/library/windows/hardware/ff557762(v=vs.85).aspx
   // - https://msdn.microsoft.com/en-us/library/windows/hardware/ff565384(v=vs.85).aspx
   // - http://stackoverflow.com/questions/23041983
   // - http://stackoverflow.com/questions/14482421

   static {
     JniLoader.loadJni();
   }

   private WindowsFileOperations() {
     // Prevent construction
   }

   /** Result of {@link #readSymlinkOrJunction}. */
   public static class ReadSymlinkOrJunctionResult {

     /** Status code, indicating success or failure. */
     public enum Status {
       OK,
       NOT_A_LINK,
       ERROR
     }

     private String result;
     private Status status;

     public ReadSymlinkOrJunctionResult(Status s, String r) {
       this.status = s;
       this.result = r;
     }

     /** Result string (junction target) or error message (depending on {@link status}). */
     public String getResult() {
       return result;
     }

     public Status getStatus() {
       return status;
     }
   }

   // Keep IS_SYMLINK_OR_JUNCTION_* values in sync with src/main/native/windows/file.cc.
   private static final int IS_SYMLINK_OR_JUNCTION_SUCCESS = 0;
   // IS_SYMLINK_OR_JUNCTION_ERROR = 1;
   private static final int IS_SYMLINK_OR_JUNCTION_DOES_NOT_EXIST = 2;

   // Keep GET_CHANGE_TIME_* values in sync with src/main/native/windows/file.cc.
   private static final int GET_CHANGE_TIME_SUCCESS = 0;
   //  private static final int GET_CHANGE_TIME_ERROR = 1;
   private static final int GET_CHANGE_TIME_DOES_NOT_EXIST = 2;
   private static final int GET_CHANGE_TIME_ACCESS_DENIED = 3;

   // Keep CREATE_JUNCTION_* values in sync with src/main/native/windows/file.h.
   private static final int CREATE_JUNCTION_SUCCESS = 0;
   // CREATE_JUNCTION_ERROR = 1;
   private static final int CREATE_JUNCTION_TARGET_NAME_TOO_LONG = 2;
   private static final int CREATE_JUNCTION_ALREADY_EXISTS_WITH_DIFFERENT_TARGET = 3;
   private static final int CREATE_JUNCTION_ALREADY_EXISTS_BUT_NOT_A_JUNCTION = 4;
   private static final int CREATE_JUNCTION_ACCESS_DENIED = 5;
   private static final int CREATE_JUNCTION_DISAPPEARED = 6;

   // Keep CREATE_SYMLINK_* values in sync with src/main/native/windows/file.h.
   private static final int CREATE_SYMLINK_SUCCESS = 0;
   // CREATE_SYMLINK_ERROR = 1;
   private static final int CREATE_SYMLINK_TARGET_IS_DIRECTORY = 2;

   // Keep DELETE_PATH_* values in sync with src/main/native/windows/file.h.
   private static final int DELETE_PATH_SUCCESS = 0;
   // DELETE_PATH_ERROR = 1;
   private static final int DELETE_PATH_DOES_NOT_EXIST = 2;
   private static final int DELETE_PATH_DIRECTORY_NOT_EMPTY = 3;
   private static final int DELETE_PATH_ACCESS_DENIED = 4;

   // Keep READ_SYMLINK_OR_JUNCTION_* values in sync with src/main/native/windows/file.h.
   private static final int READ_SYMLINK_OR_JUNCTION_SUCCESS = 0;
   // READ_SYMLINK_OR_JUNCTION_ERROR = 1;
   private static final int READ_SYMLINK_OR_JUNCTION_ACCESS_DENIED = 2;
   private static final int READ_SYMLINK_OR_JUNCTION_DOES_NOT_EXIST = 3;
   private static final int READ_SYMLINK_OR_JUNCTION_NOT_A_LINK = 4;
   private static final int READ_SYMLINK_OR_JUNCTION_UNKNOWN_LINK_TYPE = 5;

   private static native int nativeIsSymlinkOrJunction(
       String path, boolean[] result, String[] error);

   private static native int nativeGetChangeTime(
       String path, boolean followReparsePoints, long[] result, String[] error);

   private static native boolean nativeGetLongPath(String path, String[] result, String[] error);

   private static native int nativeCreateJunction(String name, String target, String[] error);

   private static native int nativeCreateSymlink(String name, String target, String[] error);

   private static native int nativeReadSymlinkOrJunction(
       String name, String[] result, String[] error);

   private static native int nativeDeletePath(String path, String[] error);

   /** Determines whether `path` is a junction point or directory symlink. */
   public static boolean isSymlinkOrJunction(String path) throws IOException {
     boolean[] result = new boolean[] {false};
     String[] error = new String[] {null};
     switch (nativeIsSymlinkOrJunction(asLongPath(path), result, error)) {
       case IS_SYMLINK_OR_JUNCTION_SUCCESS:
         return result[0];
       case IS_SYMLINK_OR_JUNCTION_DOES_NOT_EXIST:
         error[0] = "path does not exist";
         break;
       default:
         // This is IS_SYMLINK_OR_JUNCTION_ERROR (1). The JNI code puts a custom message in
         // 'error[0]'.
         break;
     }
     throw new IOException(String.format("Cannot tell if '%s' is link: %s", path, error[0]));
   }

   /** Returns the time at which the file was last changed, including metadata changes. */
   public static long getLastChangeTime(String path, boolean followReparsePoints)
       throws IOException {
     long[] result = new long[] {0};
     String[] error = new String[] {null};
     switch (nativeGetChangeTime(asLongPath(path), followReparsePoints, result, error)) {
       case GET_CHANGE_TIME_SUCCESS:
         return result[0];
       case GET_CHANGE_TIME_DOES_NOT_EXIST:
         throw new FileNotFoundException(path);
       case GET_CHANGE_TIME_ACCESS_DENIED:
         throw new AccessDeniedException(path);
       default:
         // This is GET_CHANGE_TIME_ERROR (1). The JNI code puts a custom message in 'error[0]'.
         break;
     }
     throw new IOException(String.format("Cannot get last change time of '%s': %s", path, error[0]));
   }

   /**
    * Returns the long path associated with the input `path`.
    *
    * <p>This method resolves all 8dot3 style components of the path and returns the long format. For
    * example, if the input is "C:/progra~1/micros~1" the result may be "C:\Program Files\Microsoft
    * Visual Studio 14.0". The returned path is Windows-style in that it uses backslashes, even if
    * the input uses forward slashes.
    *
    * <p>May return an UNC path if `path` or its resolution is sufficiently long.
    *
    * @throws IOException if the `path` is not found or some other I/O error occurs
    */
   public static String getLongPath(String path) throws IOException {
     String[] result = new String[] {null};
     String[] error = new String[] {null};
     if (nativeGetLongPath(asLongPath(path), result, error)) {
       return removeUncPrefixAndUseSlashes(result[0]);
     } else {
       throw new IOException(error[0]);
     }
   }

   /** Returns a Windows-style path suitable to pass to unicode WinAPI functions. */
   static String asLongPath(String path) {
     return !path.startsWith("\\\\?\\")
         ? ("\\\\?\\" + path.replace('/', '\\'))
         : path.replace('/', '\\');
   }

   private static String removeUncPrefixAndUseSlashes(String p) {
     if (p.length() >= 4
         && p.charAt(0) == '\\'
         && (p.charAt(1) == '\\' || p.charAt(1) == '?')
         && p.charAt(2) == '?'
         && p.charAt(3) == '\\') {
       p = p.substring(4);
     }
     return p.replace('\\', '/');
   }

   /**
    * Creates a junction at `name`, pointing to `target`.
    *
    * <p>Both `name` and `target` may be Unix-style Windows paths (i.e. use forward slashes), and
    * they don't need to have a UNC prefix, not even if they are longer than `MAX_PATH`. The
    * underlying logic will take care of adding the prefixes if necessary.
    *
    * @throws IOException if some error occurs
    */
   public static void createJunction(String name, String target) throws IOException {
     String[] error = new String[] {null};
     switch (nativeCreateJunction(asLongPath(name), asLongPath(target), error)) {
       case CREATE_JUNCTION_SUCCESS:
         return;
       case CREATE_JUNCTION_TARGET_NAME_TOO_LONG:
         error[0] = "target name is too long";
         break;
       case CREATE_JUNCTION_ALREADY_EXISTS_WITH_DIFFERENT_TARGET:
         error[0] = "junction already exists with different target";
         break;
       case CREATE_JUNCTION_ALREADY_EXISTS_BUT_NOT_A_JUNCTION:
         error[0] = "a file or directory already exists at the junction's path";
         break;
       case CREATE_JUNCTION_ACCESS_DENIED:
         error[0] = "access is denied";
         break;
       case CREATE_JUNCTION_DISAPPEARED:
         error[0] = "the junction's path got modified unexpectedly";
         break;
       default:
         // This is CREATE_JUNCTION_ERROR (1). The JNI code puts a custom message in 'error[0]'.
         break;
     }
     throw new IOException(
         String.format("Cannot create junction (name=%s, target=%s): %s", name, target, error[0]));
   }

   public static void createSymlink(String name, String target) throws IOException {
     String[] error = new String[] {null};
     switch (nativeCreateSymlink(asLongPath(name), asLongPath(target), error)) {
       case CREATE_SYMLINK_SUCCESS:
         return;
       case CREATE_SYMLINK_TARGET_IS_DIRECTORY:
         error[0] = "symlink target is a directory, use a junction";
         break;
       default:
         // this is CREATE_SYMLINK_ERROR (1). The JNI code puts a custom message in 'error[0]'.
         break;
     }
     throw new IOException(
         String.format("Cannot create symlink (name=%s, target=%s): %s", name, target, error[0]));
   }

   public static ReadSymlinkOrJunctionResult readSymlinkOrJunction(String name) {
     String[] target = new String[] {null};
     String[] error = new String[] {null};
     switch (nativeReadSymlinkOrJunction(asLongPath(name), target, error)) {
       case READ_SYMLINK_OR_JUNCTION_SUCCESS:
         return new ReadSymlinkOrJunctionResult(
             ReadSymlinkOrJunctionResult.Status.OK, removeUncPrefixAndUseSlashes(target[0]));
       case READ_SYMLINK_OR_JUNCTION_ACCESS_DENIED:
         error[0] = "access is denied";
         break;
       case READ_SYMLINK_OR_JUNCTION_DOES_NOT_EXIST:
         error[0] = "path does not exist";
         break;
       case READ_SYMLINK_OR_JUNCTION_NOT_A_LINK:
         return new ReadSymlinkOrJunctionResult(
             ReadSymlinkOrJunctionResult.Status.NOT_A_LINK, "path is not a link");
       case READ_SYMLINK_OR_JUNCTION_UNKNOWN_LINK_TYPE:
         error[0] = "unknown link type";
         break;
       default:
         // This is READ_SYMLINK_OR_JUNCTION_ERROR (1). The JNI code puts a custom message in
         // 'error[0]'.
         break;
     }
     return new ReadSymlinkOrJunctionResult(
         ReadSymlinkOrJunctionResult.Status.ERROR,
         String.format("Cannot read link (name=%s): %s", name, error[0]));
   }

   public static boolean deletePath(String path) throws IOException {
     String[] error = new String[] {null};
     int result = nativeDeletePath(asLongPath(path), error);
     switch (result) {
       case DELETE_PATH_SUCCESS:
         return true;
       case DELETE_PATH_DOES_NOT_EXIST:
         return false;
       case DELETE_PATH_DIRECTORY_NOT_EMPTY:
         throw new java.nio.file.DirectoryNotEmptyException(path);
       case DELETE_PATH_ACCESS_DENIED:
         throw new java.nio.file.AccessDeniedException(path);
       default:
         // This is DELETE_PATH_ERROR (1). The JNI code puts a custom message in 'error[0]'.
         throw new IOException(String.format("Cannot delete path '%s': %s", path, error[0]));
     }
   }
 }
	// Copyright 2016 The Bazel Authors. All rights reserved.
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// 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 com.google.devtools.build.lib.windows;

	import com.google.devtools.build.lib.jni.JniLoader;
	import java.io.FileNotFoundException;
	import java.io.IOException;
	import java.nio.file.AccessDeniedException;

	/** File operations on Windows. */
	public class WindowsFileOperations {

	// A note about UNC paths and path prefixes on Windows. The prefixes can be:
	// - "\\?\", meaning it's a UNC path that is passed to user mode unicode WinAPI functions
	// (e.g. CreateFileW) or a return value of theirs (e.g. GetLongPathNameW); this is the
	// prefix we'll most often see
	// - "\??\", meaning it's Device Object path; it's mostly only used by kernel/driver functions
	// but we may come across it when resolving junction targets, as the target's path is
	// specified with this prefix, see usages of DeviceIoControl with FSCTL_GET_REPARSE_POINT
	// - "\\.\", meaning it's a Device Object path again; both "\??\" and "\\.\" are shorthands
	// for the "\DosDevices\" Object Directory, so "\\.\C:" and "\??\C:" and "\DosDevices\C:"
	// and "C:\" all mean the same thing, but functions like CreateFileW don't understand the
	// fully qualified device path, only the shorthand versions; the difference between "\\.\"
	// is "\??\" is not entirely clear (one is not available while Windows is booting, but
	// that only concerns device drivers) but we most likely won't come across them anyway
	// Some of this is documented here:
	// - https://msdn.microsoft.com/en-us/library/windows/hardware/ff557762(v=vs.85).aspx
	// - https://msdn.microsoft.com/en-us/library/windows/hardware/ff565384(v=vs.85).aspx
	// - http://stackoverflow.com/questions/23041983
	// - http://stackoverflow.com/questions/14482421

	static {
	JniLoader.loadJni();
	}

	private WindowsFileOperations() {
	// Prevent construction
	}

	/** Result of {@link #readSymlinkOrJunction}. */
	public static class ReadSymlinkOrJunctionResult {

	/** Status code, indicating success or failure. */
	public enum Status {
	OK,
	NOT_A_LINK,
	ERROR
	}

	private String result;
	private Status status;

	public ReadSymlinkOrJunctionResult(Status s, String r) {
	this.status = s;
	this.result = r;
	}

	/** Result string (junction target) or error message (depending on {@link status}). */
	public String getResult() {
	return result;
	}

	public Status getStatus() {
	return status;
	}
	}

	// Keep IS_SYMLINK_OR_JUNCTION_* values in sync with src/main/native/windows/file.cc.
	private static final int IS_SYMLINK_OR_JUNCTION_SUCCESS = 0;
	// IS_SYMLINK_OR_JUNCTION_ERROR = 1;
	private static final int IS_SYMLINK_OR_JUNCTION_DOES_NOT_EXIST = 2;

	// Keep GET_CHANGE_TIME_* values in sync with src/main/native/windows/file.cc.
	private static final int GET_CHANGE_TIME_SUCCESS = 0;
	// private static final int GET_CHANGE_TIME_ERROR = 1;
	private static final int GET_CHANGE_TIME_DOES_NOT_EXIST = 2;
	private static final int GET_CHANGE_TIME_ACCESS_DENIED = 3;

	// Keep CREATE_JUNCTION_* values in sync with src/main/native/windows/file.h.
	private static final int CREATE_JUNCTION_SUCCESS = 0;
	// CREATE_JUNCTION_ERROR = 1;
	private static final int CREATE_JUNCTION_TARGET_NAME_TOO_LONG = 2;
	private static final int CREATE_JUNCTION_ALREADY_EXISTS_WITH_DIFFERENT_TARGET = 3;
	private static final int CREATE_JUNCTION_ALREADY_EXISTS_BUT_NOT_A_JUNCTION = 4;
	private static final int CREATE_JUNCTION_ACCESS_DENIED = 5;
	private static final int CREATE_JUNCTION_DISAPPEARED = 6;

	// Keep CREATE_SYMLINK_* values in sync with src/main/native/windows/file.h.
	private static final int CREATE_SYMLINK_SUCCESS = 0;
	// CREATE_SYMLINK_ERROR = 1;
	private static final int CREATE_SYMLINK_TARGET_IS_DIRECTORY = 2;

	// Keep DELETE_PATH_* values in sync with src/main/native/windows/file.h.
	private static final int DELETE_PATH_SUCCESS = 0;
	// DELETE_PATH_ERROR = 1;
	private static final int DELETE_PATH_DOES_NOT_EXIST = 2;
	private static final int DELETE_PATH_DIRECTORY_NOT_EMPTY = 3;
	private static final int DELETE_PATH_ACCESS_DENIED = 4;

	// Keep READ_SYMLINK_OR_JUNCTION_* values in sync with src/main/native/windows/file.h.
	private static final int READ_SYMLINK_OR_JUNCTION_SUCCESS = 0;
	// READ_SYMLINK_OR_JUNCTION_ERROR = 1;
	private static final int READ_SYMLINK_OR_JUNCTION_ACCESS_DENIED = 2;
	private static final int READ_SYMLINK_OR_JUNCTION_DOES_NOT_EXIST = 3;
	private static final int READ_SYMLINK_OR_JUNCTION_NOT_A_LINK = 4;
	private static final int READ_SYMLINK_OR_JUNCTION_UNKNOWN_LINK_TYPE = 5;

	private static native int nativeIsSymlinkOrJunction(
	String path, boolean[] result, String[] error);

	private static native int nativeGetChangeTime(
	String path, boolean followReparsePoints, long[] result, String[] error);

	private static native boolean nativeGetLongPath(String path, String[] result, String[] error);

	private static native int nativeCreateJunction(String name, String target, String[] error);

	private static native int nativeCreateSymlink(String name, String target, String[] error);

	private static native int nativeReadSymlinkOrJunction(
	String name, String[] result, String[] error);

	private static native int nativeDeletePath(String path, String[] error);

	/** Determines whether `path` is a junction point or directory symlink. */
	public static boolean isSymlinkOrJunction(String path) throws IOException {
	boolean[] result = new boolean[] {false};
	String[] error = new String[] {null};
	switch (nativeIsSymlinkOrJunction(asLongPath(path), result, error)) {
	case IS_SYMLINK_OR_JUNCTION_SUCCESS:
	return result[0];
	case IS_SYMLINK_OR_JUNCTION_DOES_NOT_EXIST:
	error[0] = "path does not exist";
	break;
	default:
	// This is IS_SYMLINK_OR_JUNCTION_ERROR (1). The JNI code puts a custom message in
	// 'error[0]'.
	break;
	}
	throw new IOException(String.format("Cannot tell if '%s' is link: %s", path, error[0]));
	}

	/** Returns the time at which the file was last changed, including metadata changes. */
	public static long getLastChangeTime(String path, boolean followReparsePoints)
	throws IOException {
	long[] result = new long[] {0};
	String[] error = new String[] {null};
	switch (nativeGetChangeTime(asLongPath(path), followReparsePoints, result, error)) {
	case GET_CHANGE_TIME_SUCCESS:
	return result[0];
	case GET_CHANGE_TIME_DOES_NOT_EXIST:
	throw new FileNotFoundException(path);
	case GET_CHANGE_TIME_ACCESS_DENIED:
	throw new AccessDeniedException(path);
	default:
	// This is GET_CHANGE_TIME_ERROR (1). The JNI code puts a custom message in 'error[0]'.
	break;
	}
	throw new IOException(String.format("Cannot get last change time of '%s': %s", path, error[0]));
	}

	/**
	* Returns the long path associated with the input `path`.
	*
	* <p>This method resolves all 8dot3 style components of the path and returns the long format. For
	* example, if the input is "C:/progra~1/micros~1" the result may be "C:\Program Files\Microsoft
	* Visual Studio 14.0". The returned path is Windows-style in that it uses backslashes, even if
	* the input uses forward slashes.
	*
	* <p>May return an UNC path if `path` or its resolution is sufficiently long.
	*
	* @throws IOException if the `path` is not found or some other I/O error occurs
	*/
	public static String getLongPath(String path) throws IOException {
	String[] result = new String[] {null};
	String[] error = new String[] {null};
	if (nativeGetLongPath(asLongPath(path), result, error)) {
	return removeUncPrefixAndUseSlashes(result[0]);
	} else {
	throw new IOException(error[0]);
	}
	}

	/** Returns a Windows-style path suitable to pass to unicode WinAPI functions. */
	static String asLongPath(String path) {
	return !path.startsWith("\\\\?\\")
	? ("\\\\?\\" + path.replace('/', '\\'))
	: path.replace('/', '\\');
	}

	private static String removeUncPrefixAndUseSlashes(String p) {
	if (p.length() >= 4
	&& p.charAt(0) == '\\'
	&& (p.charAt(1) == '\\' \|\| p.charAt(1) == '?')
	&& p.charAt(2) == '?'
	&& p.charAt(3) == '\\') {
	p = p.substring(4);
	}
	return p.replace('\\', '/');
	}

	/**
	* Creates a junction at `name`, pointing to `target`.
	*
	* <p>Both `name` and `target` may be Unix-style Windows paths (i.e. use forward slashes), and
	* they don't need to have a UNC prefix, not even if they are longer than `MAX_PATH`. The
	* underlying logic will take care of adding the prefixes if necessary.
	*
	* @throws IOException if some error occurs
	*/
	public static void createJunction(String name, String target) throws IOException {
	String[] error = new String[] {null};
	switch (nativeCreateJunction(asLongPath(name), asLongPath(target), error)) {
	case CREATE_JUNCTION_SUCCESS:
	return;
	case CREATE_JUNCTION_TARGET_NAME_TOO_LONG:
	error[0] = "target name is too long";
	break;
	case CREATE_JUNCTION_ALREADY_EXISTS_WITH_DIFFERENT_TARGET:
	error[0] = "junction already exists with different target";
	break;
	case CREATE_JUNCTION_ALREADY_EXISTS_BUT_NOT_A_JUNCTION:
	error[0] = "a file or directory already exists at the junction's path";
	break;
	case CREATE_JUNCTION_ACCESS_DENIED:
	error[0] = "access is denied";
	break;
	case CREATE_JUNCTION_DISAPPEARED:
	error[0] = "the junction's path got modified unexpectedly";
	break;
	default:
	// This is CREATE_JUNCTION_ERROR (1). The JNI code puts a custom message in 'error[0]'.
	break;
	}
	throw new IOException(
	String.format("Cannot create junction (name=%s, target=%s): %s", name, target, error[0]));
	}

	public static void createSymlink(String name, String target) throws IOException {
	String[] error = new String[] {null};
	switch (nativeCreateSymlink(asLongPath(name), asLongPath(target), error)) {
	case CREATE_SYMLINK_SUCCESS:
	return;
	case CREATE_SYMLINK_TARGET_IS_DIRECTORY:
	error[0] = "symlink target is a directory, use a junction";
	break;
	default:
	// this is CREATE_SYMLINK_ERROR (1). The JNI code puts a custom message in 'error[0]'.
	break;
	}
	throw new IOException(
	String.format("Cannot create symlink (name=%s, target=%s): %s", name, target, error[0]));
	}

	public static ReadSymlinkOrJunctionResult readSymlinkOrJunction(String name) {
	String[] target = new String[] {null};
	String[] error = new String[] {null};
	switch (nativeReadSymlinkOrJunction(asLongPath(name), target, error)) {
	case READ_SYMLINK_OR_JUNCTION_SUCCESS:
	return new ReadSymlinkOrJunctionResult(
	ReadSymlinkOrJunctionResult.Status.OK, removeUncPrefixAndUseSlashes(target[0]));
	case READ_SYMLINK_OR_JUNCTION_ACCESS_DENIED:
	error[0] = "access is denied";
	break;
	case READ_SYMLINK_OR_JUNCTION_DOES_NOT_EXIST:
	error[0] = "path does not exist";
	break;
	case READ_SYMLINK_OR_JUNCTION_NOT_A_LINK:
	return new ReadSymlinkOrJunctionResult(
	ReadSymlinkOrJunctionResult.Status.NOT_A_LINK, "path is not a link");
	case READ_SYMLINK_OR_JUNCTION_UNKNOWN_LINK_TYPE:
	error[0] = "unknown link type";
	break;
	default:
	// This is READ_SYMLINK_OR_JUNCTION_ERROR (1). The JNI code puts a custom message in
	// 'error[0]'.
	break;
	}
	return new ReadSymlinkOrJunctionResult(
	ReadSymlinkOrJunctionResult.Status.ERROR,
	String.format("Cannot read link (name=%s): %s", name, error[0]));
	}

	public static boolean deletePath(String path) throws IOException {
	String[] error = new String[] {null};
	int result = nativeDeletePath(asLongPath(path), error);
	switch (result) {
	case DELETE_PATH_SUCCESS:
	return true;
	case DELETE_PATH_DOES_NOT_EXIST:
	return false;
	case DELETE_PATH_DIRECTORY_NOT_EMPTY:
	throw new java.nio.file.DirectoryNotEmptyException(path);
	case DELETE_PATH_ACCESS_DENIED:
	throw new java.nio.file.AccessDeniedException(path);
	default:
	// This is DELETE_PATH_ERROR (1). The JNI code puts a custom message in 'error[0]'.
	throw new IOException(String.format("Cannot delete path '%s': %s", path, error[0]));
	}
	}
	}