/**
* Constructs a GlobDescriptor.
*
* @param packageId the name of the owner package (must be an existing package)
* @param subdir the subdirectory being looked at (must exist and must be a directory. It's
* assumed that there are no other packages between {@code packageName} and {@code subdir}.
* @param pattern a valid glob pattern
* @param excludeDirs true if directories should be excluded from results
*/
GlobDescriptor(
PackageIdentifier packageId, PathFragment subdir, String pattern, boolean excludeDirs) {
this.packageId = Preconditions.checkNotNull(packageId);
this.subdir = Preconditions.checkNotNull(subdir);
this.pattern = Preconditions.checkNotNull(StringCanonicalizer.intern(pattern));
this.excludeDirs = excludeDirs;
}
/**
* Returns the path formed by appending the single non-special segment "baseName" to this path.
*
* <p>You should almost always use {@link #getRelative} instead, which has the same performance
* characteristics if the given name is a valid base name, and which also works for '.', '..', and
* strings containing '/'.
*
* @throws IllegalArgumentException if {@code baseName} is not a valid base name according to
* {@link FileSystemUtils#checkBaseName}
*/
public PathFragment getChild(String baseName) {
FileSystemUtils.checkBaseName(baseName);
baseName = StringCanonicalizer.intern(baseName);
String[] newSegments = Arrays.copyOf(segments, segments.length + 1);
newSegments[newSegments.length - 1] = baseName;
return new PathFragment(driveLetter, isAbsolute, newSegments);
}
/** Lower-level API. Create a PathFragment, interning segments. */
public static PathFragment create(char driveLetter, boolean isAbsolute, String[] segments) {
String[] internedSegments = new String[segments.length];
for (int i = 0; i < segments.length; i++) {
internedSegments[i] = StringCanonicalizer.intern(segments[i]);
}
return new PathFragment(driveLetter, isAbsolute, segments);
}
/**
* Segments the string passed in as argument and returns an array of strings. The split is
* performed along occurrences of (sequences of) the slash character.
*
* @param toSegment the string to segment
* @param offset how many characters from the start of the string to ignore.
*/
private static String[] segment(String toSegment, int offset) {
char[] chars = toSegment.toCharArray();
int length = chars.length;
// Handle "/" and "" quickly.
if (length == offset) {
return new String[0];
}
// We make two passes through the array of characters: count & alloc,
// because simply using ArrayList was a bottleneck showing up during profiling.
int seg = 0;
int start = offset;
for (int i = offset; i < length; i++) {
if (isSeparator(chars[i])) {
if (i > start) { // to skip repeated separators
seg++;
}
start = i + 1;
}
}
if (start < length) {
seg++;
}
String[] result = new String[seg];
seg = 0;
start = offset;
for (int i = offset; i < length; i++) {
if (isSeparator(chars[i])) {
if (i > start) { // to skip repeated separators
// Make a copy of the String here to allow the interning to save memory. String.substring
// does not make a copy, but refers to the original char array, preventing garbage
// collection of the parts that are unnecessary.
result[seg] = StringCanonicalizer.intern(new String(chars, start, i - start));
seg++;
}
start = i + 1;
}
}
if (start < length) {
result[seg] = StringCanonicalizer.intern(new String(chars, start, length - start));
seg++;
}
return result;
}
/**
* Makes sure that name is a valid repository name and creates a new RepositoryName using it.
*
* @throws SyntaxException if the name is invalid.
*/
public static RepositoryName create(String name) throws SyntaxException {
String errorMessage = validate(name);
if (errorMessage != null) {
errorMessage =
"invalid repository name '"
+ StringUtilities.sanitizeControlChars(name)
+ "': "
+ errorMessage;
throw new SyntaxException(errorMessage);
}
return new RepositoryName(StringCanonicalizer.intern(name));
}
/**
* Returns the path string using '/' as the name-separator character. Returns "" if the path is
* both relative and empty.
*/
public String getPathString() {
// Double-checked locking works, even without volatile, because path is a String, according to:
// http://www.cs.umd.edu/~pugh/java/memoryModel/DoubleCheckedLocking.html
if (path == null) {
synchronized (this) {
if (path == null) {
path = StringCanonicalizer.intern(joinSegments(SEPARATOR_CHAR));
}
}
}
return path;
}