package com.digiarea.closure.core;
import java.io.File;
import java.util.Arrays;
public class Path implements IPath {
/** masks for separator values */
private static final int HAS_LEADING = 1;
private static final int IS_UNC = 2;
private static final int HAS_TRAILING = 4;
private static final int ALL_SEPARATORS = HAS_LEADING | IS_UNC
| HAS_TRAILING;
/** Constant empty string value. */
private static final String EMPTY_STRING = ""; //$NON-NLS-1$
/** Constant value indicating no segments */
private static final String[] NO_SEGMENTS = new String[0];
/** Constant value containing the empty path with no device. */
public static final Path EMPTY = new Path(EMPTY_STRING);
/** Mask for all bits that are involved in the hash code */
private static final int HASH_MASK = ~HAS_TRAILING;
/** Constant root path string (<code>"/"</code>). */
private static final String ROOT_STRING = "/"; //$NON-NLS-1$
/** Constant value containing the root path with no device. */
public static final Path ROOT = new Path(ROOT_STRING);
/** Constant value indicating if the current platform is Windows */
private static final boolean WINDOWS = java.io.File.separatorChar == '\\';
/** The device id string. May be null if there is no device. */
private String device = null;
/** The path segments */
private String[] segments;
/** flags indicating separators (has leading, is UNC, has trailing) */
private int separators;
/**
* Constructs a new path from the given string path. The string path must
* represent a valid file system path on the local file system. The path is
* canonicalized and double slashes are removed except at the beginning. (to
* handle UNC paths). All forward slashes ('/') are treated as segment
* delimiters, and any segment and device delimiters for the local file
* system are also respected.
*
* @param pathString
* the portable string path
* @see IPath#toPortableString()
* @since 3.1
*/
public static IPath fromOSString(String pathString) {
return new Path(pathString);
}
/**
* Constructs a new path from the given path string. The path string must
* have been produced by a previous call to
* <code>IPath.toPortableString</code>.
*
* @param pathString
* the portable path string
* @see IPath#toPortableString()
* @since 3.1
*/
public static IPath fromPortableString(String pathString) {
int firstMatch = pathString.indexOf(DEVICE_SEPARATOR) + 1;
// no extra work required if no device characters
if (firstMatch <= 0)
return new Path().initialize(null, pathString);
// if we find a single colon, then the path has a device
String devicePart = null;
int pathLength = pathString.length();
if (firstMatch == pathLength
|| pathString.charAt(firstMatch) != DEVICE_SEPARATOR) {
devicePart = pathString.substring(0, firstMatch);
pathString = pathString.substring(firstMatch, pathLength);
}
// optimize for no colon literals
if (pathString.indexOf(DEVICE_SEPARATOR) == -1)
return new Path().initialize(devicePart, pathString);
// contract colon literals
char[] chars = pathString.toCharArray();
int readOffset = 0, writeOffset = 0, length = chars.length;
while (readOffset < length) {
if (chars[readOffset] == DEVICE_SEPARATOR)
if (++readOffset >= length)
break;
chars[writeOffset++] = chars[readOffset++];
}
return new Path().initialize(devicePart, new String(chars, 0,
writeOffset));
}
private Path() {
// not allowed
}
/**
* Constructs a new path from the given string path. The string path must
* represent a valid file system path on the local file system. The path is
* canonicalized and double slashes are removed except at the beginning. (to
* handle UNC paths). All forward slashes ('/') are treated as segment
* delimiters, and any segment and device delimiters for the local file
* system are also respected (such as colon (':') and backslash ('\') on
* some file systems).
*
* @param fullPath
* the string path
* @see #isValidPath(String)
*/
public Path(String fullPath) {
String devicePart = null;
if (WINDOWS) {
// convert backslash to forward slash
fullPath = fullPath.indexOf('\\') == -1 ? fullPath : fullPath
.replace('\\', SEPARATOR);
// extract device
int i = fullPath.indexOf(DEVICE_SEPARATOR);
if (i != -1) {
// remove leading slash from device part to handle output of
// URL.getFile()
int start = fullPath.charAt(0) == SEPARATOR ? 1 : 0;
devicePart = fullPath.substring(start, i + 1);
fullPath = fullPath.substring(i + 1, fullPath.length());
}
}
initialize(devicePart, fullPath);
}
/**
* Constructs a new path from the given device id and string path. The given
* string path must be valid. The path is canonicalized and double slashes
* are removed except at the beginning (to handle UNC paths). All forward
* slashes ('/') are treated as segment delimiters, and any segment
* delimiters for the local file system are also respected (such as
* backslash ('\') on some file systems).
*
* @param device
* the device id
* @param path
* the string path
* @see #isValidPath(String)
* @see #setDevice(String)
*/
public Path(String device, String path) {
if (WINDOWS) {
// convert backslash to forward slash
path = path.indexOf('\\') == -1 ? path : path.replace('\\',
SEPARATOR);
}
initialize(device, path);
}
private Path(String device, String[] segments, int _separators) {
// no segment validations are done for performance reasons
this.segments = segments;
this.device = device;
// hash code is cached in all but the bottom three bits of the
// separators field
this.separators = (computeHashCode() << 3)
| (_separators & ALL_SEPARATORS);
}
public IPath addFileExtension(String extension) {
if (isRoot() || isEmpty() || hasTrailingSeparator())
return this;
int len = segments.length;
String[] newSegments = new String[len];
System.arraycopy(segments, 0, newSegments, 0, len - 1);
newSegments[len - 1] = segments[len - 1] + '.' + extension;
return new Path(device, newSegments, separators);
}
public IPath addTrailingSeparator() {
if (hasTrailingSeparator() || isRoot()) {
return this;
}
// XXX workaround, see 1GIGQ9V
if (isEmpty()) {
return new Path(device, segments, HAS_LEADING);
}
return new Path(device, segments, separators | HAS_TRAILING);
}
public IPath append(IPath tail) {
// optimize some easy cases
if (tail == null || tail.segmentCount() == 0)
return this;
// these call chains look expensive, but in most cases they are no-ops
if (this.isEmpty())
return tail.setDevice(device).makeRelative().makeUNC(isUNC());
if (this.isRoot())
return tail.setDevice(device).makeAbsolute().makeUNC(isUNC());
// concatenate the two segment arrays
int myLen = segments.length;
int tailLen = tail.segmentCount();
String[] newSegments = new String[myLen + tailLen];
System.arraycopy(segments, 0, newSegments, 0, myLen);
for (int i = 0; i < tailLen; i++) {
newSegments[myLen + i] = tail.segment(i);
}
// use my leading separators and the tail's trailing separator
Path result = new Path(device, newSegments,
(separators & (HAS_LEADING | IS_UNC))
| (tail.hasTrailingSeparator() ? HAS_TRAILING : 0));
String tailFirstSegment = newSegments[myLen];
if (tailFirstSegment.equals("..") || tailFirstSegment.equals(".")) { //$NON-NLS-1$ //$NON-NLS-2$
result.canonicalize();
}
return result;
}
public IPath append(String tail) {
// optimize addition of a single segment
if (tail.indexOf(SEPARATOR) == -1
&& tail.indexOf("\\") == -1 && tail.indexOf(DEVICE_SEPARATOR) == -1) { //$NON-NLS-1$
int tailLength = tail.length();
if (tailLength < 3) {
// some special cases
if (tailLength == 0 || ".".equals(tail)) { //$NON-NLS-1$
return this;
}
if ("..".equals(tail)) //$NON-NLS-1$
return removeLastSegments(1);
}
// just add the segment
int myLen = segments.length;
String[] newSegments = new String[myLen + 1];
System.arraycopy(segments, 0, newSegments, 0, myLen);
newSegments[myLen] = tail;
return new Path(device, newSegments, separators & ~HAS_TRAILING);
}
// go with easy implementation
return append(new Path(tail));
}
/**
* Destructively converts this path to its canonical form.
* <p>
* In its canonical form, a path does not have any "." segments, and parent
* references ("..") are collapsed where possible.
* </p>
*
* @return true if the path was modified, and false otherwise.
*/
private boolean canonicalize() {
// look for segments that need canonicalizing
for (int i = 0, max = segments.length; i < max; i++) {
String segment = segments[i];
if (segment.charAt(0) == '.'
&& (segment.equals("..") || segment.equals("."))) { //$NON-NLS-1$ //$NON-NLS-2$
// path needs to be canonicalized
collapseParentReferences();
// paths of length 0 have no trailing separator
if (segments.length == 0)
separators &= (HAS_LEADING | IS_UNC);
// recompute hash because canonicalize affects hash
separators = (separators & ALL_SEPARATORS)
| (computeHashCode() << 3);
return true;
}
}
return false;
}
public Object clone() {
try {
return super.clone();
} catch (CloneNotSupportedException e) {
return null;
}
}
/**
* Destructively removes all occurrences of ".." segments from this path.
*/
private void collapseParentReferences() {
int segmentCount = segments.length;
String[] stack = new String[segmentCount];
int stackPointer = 0;
for (int i = 0; i < segmentCount; i++) {
String segment = segments[i];
if (segment.equals("..")) { //$NON-NLS-1$
if (stackPointer == 0) {
// if the stack is empty we are going out of our scope
// so we need to accumulate segments. But only if the
// original
// path is relative. If it is absolute then we can't go any
// higher than
// root so simply toss the .. references.
if (!isAbsolute())
stack[stackPointer++] = segment; // stack push
} else {
// if the top is '..' then we are accumulating segments so
// don't pop
if ("..".equals(stack[stackPointer - 1])) //$NON-NLS-1$
stack[stackPointer++] = ".."; //$NON-NLS-1$
else
stackPointer--;
// stack pop
}
// collapse current references
} else if (!segment.equals(".") || segmentCount == 1) //$NON-NLS-1$
stack[stackPointer++] = segment; // stack push
}
// if the number of segments hasn't changed, then no modification needed
if (stackPointer == segmentCount)
return;
// build the new segment array backwards by popping the stack
String[] newSegments = new String[stackPointer];
System.arraycopy(stack, 0, newSegments, 0, stackPointer);
this.segments = newSegments;
}
/**
* Removes duplicate slashes from the given path, with the exception of
* leading double slash which represents a UNC path.
*/
private String collapseSlashes(String path) {
int length = path.length();
// if the path is only 0, 1 or 2 chars long then it could not possibly
// have illegal
// duplicate slashes.
if (length < 3)
return path;
// check for an occurrence of // in the path. Start at index 1 to ensure
// we skip leading UNC //
// If there are no // then there is nothing to collapse so just return.
if (path.indexOf("//", 1) == -1) //$NON-NLS-1$
return path;
// We found an occurrence of // in the path so do the slow collapse.
char[] result = new char[path.length()];
int count = 0;
boolean hasPrevious = false;
char[] characters = path.toCharArray();
for (int index = 0; index < characters.length; index++) {
char c = characters[index];
if (c == SEPARATOR) {
if (hasPrevious) {
// skip double slashes, except for beginning of UNC.
// note that a UNC path can't have a device.
if (device == null && index == 1) {
result[count] = c;
count++;
}
} else {
hasPrevious = true;
result[count] = c;
count++;
}
} else {
hasPrevious = false;
result[count] = c;
count++;
}
}
return new String(result, 0, count);
}
private int computeHashCode() {
int hash = device == null ? 17 : device.hashCode();
int segmentCount = segments.length;
for (int i = 0; i < segmentCount; i++) {
// this function tends to given a fairly even distribution
hash = hash * 37 + segments[i].hashCode();
}
return hash;
}
private int computeLength() {
int length = 0;
if (device != null)
length += device.length();
if ((separators & HAS_LEADING) != 0)
length++;
if ((separators & IS_UNC) != 0)
length++;
// add the segment lengths
int max = segments.length;
if (max > 0) {
for (int i = 0; i < max; i++) {
length += segments[i].length();
}
// add the separator lengths
length += max - 1;
}
if ((separators & HAS_TRAILING) != 0)
length++;
return length;
}
private int computeSegmentCount(String path) {
int len = path.length();
if (len == 0 || (len == 1 && path.charAt(0) == SEPARATOR)) {
return 0;
}
int count = 1;
int prev = -1;
int i;
while ((i = path.indexOf(SEPARATOR, prev + 1)) != -1) {
if (i != prev + 1 && i != len) {
++count;
}
prev = i;
}
if (path.charAt(len - 1) == SEPARATOR) {
--count;
}
return count;
}
/**
* Computes the segment array for the given canonicalized path.
*/
private String[] computeSegments(String path) {
// performance sensitive --- avoid creating garbage
int segmentCount = computeSegmentCount(path);
if (segmentCount == 0)
return NO_SEGMENTS;
String[] newSegments = new String[segmentCount];
int len = path.length();
// check for initial slash
int firstPosition = (path.charAt(0) == SEPARATOR) ? 1 : 0;
// check for UNC
if (firstPosition == 1 && len > 1 && (path.charAt(1) == SEPARATOR))
firstPosition = 2;
int lastPosition = (path.charAt(len - 1) != SEPARATOR) ? len - 1
: len - 2;
// for non-empty paths, the number of segments is
// the number of slashes plus 1, ignoring any leading
// and trailing slashes
int next = firstPosition;
for (int i = 0; i < segmentCount; i++) {
int start = next;
int end = path.indexOf(SEPARATOR, next);
if (end == -1) {
newSegments[i] = path.substring(start, lastPosition + 1);
} else {
newSegments[i] = path.substring(start, end);
}
next = end + 1;
}
return newSegments;
}
/**
* Returns the platform-neutral encoding of the given segment onto the given
* string buffer. This escapes literal colon characters with double colons.
*/
private void encodeSegment(String string, StringBuffer buf) {
int len = string.length();
for (int i = 0; i < len; i++) {
char c = string.charAt(i);
buf.append(c);
if (c == DEVICE_SEPARATOR)
buf.append(DEVICE_SEPARATOR);
}
}
public boolean equals(Object obj) {
if (this == obj)
return true;
if (!(obj instanceof Path))
return false;
Path target = (Path) obj;
// check leading separators and hash code
if ((separators & HASH_MASK) != (target.separators & HASH_MASK))
return false;
String[] targetSegments = target.segments;
int i = segments.length;
// check segment count
if (i != targetSegments.length)
return false;
// check segments in reverse order - later segments more likely to
// differ
while (--i >= 0)
if (!segments[i].equals(targetSegments[i]))
return false;
// check device last (least likely to differ)
return device == target.device
|| (device != null && device.equals(target.device));
}
public String getDevice() {
return device;
}
public String getFileExtension() {
if (hasTrailingSeparator()) {
return null;
}
String lastSegment = lastSegment();
if (lastSegment == null) {
return null;
}
int index = lastSegment.lastIndexOf('.');
if (index == -1) {
return null;
}
return lastSegment.substring(index + 1);
}
public int hashCode() {
return separators & HASH_MASK;
}
public boolean hasTrailingSeparator() {
return (separators & HAS_TRAILING) != 0;
}
private IPath initialize(String deviceString, String path) {
if (path == null) {
throw new NullPointerException();
}
this.device = deviceString;
path = collapseSlashes(path);
int len = path.length();
// compute the separators array
if (len < 2) {
if (len == 1 && path.charAt(0) == SEPARATOR) {
this.separators = HAS_LEADING;
} else {
this.separators = 0;
}
} else {
boolean hasLeading = path.charAt(0) == SEPARATOR;
boolean isUNC = hasLeading && path.charAt(1) == SEPARATOR;
// UNC path of length two has no trailing separator
boolean hasTrailing = !(isUNC && len == 2)
&& path.charAt(len - 1) == SEPARATOR;
separators = hasLeading ? HAS_LEADING : 0;
if (isUNC)
separators |= IS_UNC;
if (hasTrailing)
separators |= HAS_TRAILING;
}
// compute segments and ensure canonical form
segments = computeSegments(path);
if (!canonicalize()) {
// compute hash now because canonicalize didn't need to do it
separators = (separators & ALL_SEPARATORS)
| (computeHashCode() << 3);
}
return this;
}
public boolean isAbsolute() {
// it's absolute if it has a leading separator
return (separators & HAS_LEADING) != 0;
}
public boolean isEmpty() {
// true if no segments and no leading prefix
return segments.length == 0
&& ((separators & ALL_SEPARATORS) != HAS_LEADING);
}
public boolean isPrefixOf(IPath anotherPath) {
if (device == null) {
if (anotherPath.getDevice() != null) {
return false;
}
} else {
if (!device.equalsIgnoreCase(anotherPath.getDevice())) {
return false;
}
}
if (isEmpty() || (isRoot() && anotherPath.isAbsolute())) {
return true;
}
int len = segments.length;
if (len > anotherPath.segmentCount()) {
return false;
}
for (int i = 0; i < len; i++) {
if (!segments[i].equals(anotherPath.segment(i)))
return false;
}
return true;
}
public boolean isRoot() {
// must have no segments, a leading separator, and not be a UNC path.
return this == ROOT
|| (segments.length == 0 && ((separators & ALL_SEPARATORS) == HAS_LEADING));
}
public boolean isUNC() {
if (device != null)
return false;
return (separators & IS_UNC) != 0;
}
public boolean isValidPath(String path) {
Path test = new Path(path);
for (int i = 0, max = test.segmentCount(); i < max; i++)
if (!isValidSegment(test.segment(i)))
return false;
return true;
}
public boolean isValidSegment(String segment) {
int size = segment.length();
if (size == 0)
return false;
for (int i = 0; i < size; i++) {
char c = segment.charAt(i);
if (c == '/')
return false;
if (WINDOWS && (c == '\\' || c == ':'))
return false;
}
return true;
}
public String lastSegment() {
int len = segments.length;
return len == 0 ? null : segments[len - 1];
}
public IPath makeAbsolute() {
if (isAbsolute()) {
return this;
}
Path result = new Path(device, segments, separators | HAS_LEADING);
if (result.segmentCount() > 0) {
String first = result.segment(0);
if (first.equals("..") || first.equals(".")) { //$NON-NLS-1$ //$NON-NLS-2$
result.canonicalize();
}
}
return result;
}
public IPath makeRelative() {
if (!isAbsolute()) {
return this;
}
return new Path(device, segments, separators & HAS_TRAILING);
}
public IPath makeRelativeTo(IPath base) {
if (device != base.getDevice()
&& (device == null || !device
.equalsIgnoreCase(base.getDevice())))
return this;
int commonLength = matchingFirstSegments(base);
final int differenceLength = base.segmentCount() - commonLength;
final int newSegmentLength = differenceLength + segmentCount()
- commonLength;
if (newSegmentLength == 0)
return Path.EMPTY;
String[] newSegments = new String[newSegmentLength];
// add parent references for each segment different from the base
Arrays.fill(newSegments, 0, differenceLength, ".."); //$NON-NLS-1$
// append the segments of this path not in common with the base
System.arraycopy(segments, commonLength, newSegments, differenceLength,
newSegmentLength - differenceLength);
return new Path(null, newSegments, separators & HAS_TRAILING);
}
public IPath makeUNC(boolean toUNC) {
// if we are already in the right form then just return
if (!(toUNC ^ isUNC()))
return this;
int newSeparators = this.separators;
if (toUNC) {
newSeparators |= HAS_LEADING | IS_UNC;
} else {
newSeparators &= HAS_LEADING | HAS_TRAILING;
}
return new Path(toUNC ? null : device, segments, newSeparators);
}
public int matchingFirstSegments(IPath anotherPath) {
if (anotherPath == null) {
throw new NullPointerException();
}
int anotherPathLen = anotherPath.segmentCount();
int max = Math.min(segments.length, anotherPathLen);
int count = 0;
for (int i = 0; i < max; i++) {
if (!segments[i].equals(anotherPath.segment(i))) {
return count;
}
count++;
}
return count;
}
public IPath removeFileExtension() {
String extension = getFileExtension();
if (extension == null || extension.equals("")) { //$NON-NLS-1$
return this;
}
String lastSegment = lastSegment();
int index = lastSegment.lastIndexOf(extension) - 1;
return removeLastSegments(1).append(lastSegment.substring(0, index));
}
public IPath removeFirstSegments(int count) {
if (count == 0)
return this;
if (count >= segments.length) {
return new Path(device, NO_SEGMENTS, 0);
}
if (count < 0) {
throw new RuntimeException();
}
int newSize = segments.length - count;
String[] newSegments = new String[newSize];
System.arraycopy(this.segments, count, newSegments, 0, newSize);
return new Path(device, newSegments, separators & HAS_TRAILING);
}
public IPath removeLastSegments(int count) {
if (count == 0)
return this;
if (count >= segments.length) {
// result will have no trailing separator
return new Path(device, NO_SEGMENTS, separators
& (HAS_LEADING | IS_UNC));
}
if (count < 0) {
throw new RuntimeException();
}
int newSize = segments.length - count;
String[] newSegments = new String[newSize];
System.arraycopy(this.segments, 0, newSegments, 0, newSize);
return new Path(device, newSegments, separators);
}
public IPath removeTrailingSeparator() {
if (!hasTrailingSeparator()) {
return this;
}
return new Path(device, segments, separators & (HAS_LEADING | IS_UNC));
}
public String segment(int index) {
if (index >= segments.length)
return null;
return segments[index];
}
public int segmentCount() {
return segments.length;
}
public String[] segments() {
String[] segmentCopy = new String[segments.length];
System.arraycopy(segments, 0, segmentCopy, 0, segments.length);
return segmentCopy;
}
public IPath setDevice(String value) {
if (value != null) {
if (value.indexOf(IPath.DEVICE_SEPARATOR) == (value.length() - 1)) {
throw new RuntimeException(
"Last character should be the device separator");
}
}
if (value == device || (value != null && value.equals(device)))
return this;
return new Path(value, segments, separators);
}
public File toFile() {
return new File(toOSString());
}
public String toOSString() {
int resultSize = computeLength();
if (resultSize <= 0)
return EMPTY_STRING;
char FILE_SEPARATOR = File.separatorChar;
char[] result = new char[resultSize];
int offset = 0;
if (device != null) {
int size = device.length();
device.getChars(0, size, result, offset);
offset += size;
}
if ((separators & HAS_LEADING) != 0)
result[offset++] = FILE_SEPARATOR;
if ((separators & IS_UNC) != 0)
result[offset++] = FILE_SEPARATOR;
int len = segments.length - 1;
if (len >= 0) {
// append all but the last segment, with separators
for (int i = 0; i < len; i++) {
int size = segments[i].length();
segments[i].getChars(0, size, result, offset);
offset += size;
result[offset++] = FILE_SEPARATOR;
}
// append the last segment
int size = segments[len].length();
segments[len].getChars(0, size, result, offset);
offset += size;
}
if ((separators & HAS_TRAILING) != 0)
result[offset++] = FILE_SEPARATOR;
return new String(result);
}
public String toPortableString() {
int resultSize = computeLength();
if (resultSize <= 0)
return EMPTY_STRING;
StringBuffer result = new StringBuffer(resultSize);
if (device != null)
result.append(device);
if ((separators & HAS_LEADING) != 0)
result.append(SEPARATOR);
if ((separators & IS_UNC) != 0)
result.append(SEPARATOR);
int len = segments.length;
// append all segments with separators
for (int i = 0; i < len; i++) {
if (segments[i].indexOf(DEVICE_SEPARATOR) >= 0)
encodeSegment(segments[i], result);
else
result.append(segments[i]);
if (i < len - 1 || (separators & HAS_TRAILING) != 0)
result.append(SEPARATOR);
}
return result.toString();
}
public String toString() {
int resultSize = computeLength();
if (resultSize <= 0)
return EMPTY_STRING;
char[] result = new char[resultSize];
int offset = 0;
if (device != null) {
int size = device.length();
device.getChars(0, size, result, offset);
offset += size;
}
if ((separators & HAS_LEADING) != 0)
result[offset++] = SEPARATOR;
if ((separators & IS_UNC) != 0)
result[offset++] = SEPARATOR;
int len = segments.length - 1;
if (len >= 0) {
// append all but the last segment, with separators
for (int i = 0; i < len; i++) {
int size = segments[i].length();
segments[i].getChars(0, size, result, offset);
offset += size;
result[offset++] = SEPARATOR;
}
// append the last segment
int size = segments[len].length();
segments[len].getChars(0, size, result, offset);
offset += size;
}
if ((separators & HAS_TRAILING) != 0)
result[offset++] = SEPARATOR;
return new String(result);
}
public IPath uptoSegment(int count) {
if (count == 0)
return new Path(device, NO_SEGMENTS, separators
& (HAS_LEADING | IS_UNC));
if (count >= segments.length)
return this;
if (count < 0) {
throw new RuntimeException("Invalid parameter to Path.uptoSegment");
}
String[] newSegments = new String[count];
System.arraycopy(segments, 0, newSegments, 0, count);
return new Path(device, newSegments, separators);
}
}