public FileChannel truncate(long newLength) throws IOException {
if (newLength >= length) {
return this;
}
filePointer = Math.min(filePointer, newLength);
int newFileCount = 1 + (int) (newLength / maxLength);
if (newFileCount < list.length) {
// delete some of the files
FileChannel[] newList = new FileChannel[newFileCount];
// delete backwards, so that truncating is somewhat transactional
for (int i = list.length - 1; i >= newFileCount; i--) {
// verify the file is writable
list[i].truncate(0);
list[i].close();
try {
file.getBase(i).delete();
} catch (DbException e) {
throw DbException.convertToIOException(e);
}
}
System.arraycopy(list, 0, newList, 0, newList.length);
list = newList;
}
long size = newLength - maxLength * (newFileCount - 1);
list[list.length - 1].truncate(size);
this.length = newLength;
return this;
}
public void moveTo(FilePath path) {
FilePathSplit newName = (FilePathSplit) path;
for (int i = 0; ; i++) {
FilePath o = getBase(i);
if (o.exists()) {
o.moveTo(newName.getBase(i));
} else {
break;
}
}
}
private FileChannel getFileChannel() throws IOException {
int id = (int) (filePointer / maxLength);
while (id >= list.length) {
int i = list.length;
FileChannel[] newList = new FileChannel[i + 1];
System.arraycopy(list, 0, newList, 0, i);
FilePath f = file.getBase(i);
newList[i] = f.open(mode);
list = newList;
}
return list[id];
}