/**
* Performs a wildcard search for the specified token.
*
* @param token token to look for
* @return iterator
*/
private synchronized IndexIterator wc(final byte[] token) {
final FTIndexIterator it = FTIndexIterator.FTEMPTY;
final FTWildcard wc = new FTWildcard(token);
if (!wc.parse()) return it;
final IntList pr = new IntList();
final IntList ps = new IntList();
final byte[] pref = wc.prefix();
final int pl = pref.length, tl = tp.length;
final int l = Math.min(tl - 1, wc.max());
for (int ti = pl; ti <= l; ti++) {
int i = tp[ti];
if (i == -1) continue;
int c = ti + 1;
int e = -1;
while (c < tl && e == -1) e = tp[c++];
i = find(pref, i, e, ti);
while (i < e) {
final byte[] t = inY.readBytes(i, ti);
if (!startsWith(t, pref)) break;
if (wc.match(t)) {
inZ.cursor(pointer(i, ti));
final int s = size(i, ti);
for (int d = 0; d < s; d++) {
pr.add(inZ.readNum());
ps.add(inZ.readNum());
}
}
i += ti + ENTRY;
}
}
return iter(new FTCache(pr, ps), token);
}
/**
* Returns next token.
*
* @return byte[] token
*/
private byte[] token() {
if (tp[tp.length - 1] == ptok) return EMPTY;
if (tp[ntl] == ptok || ntl == 0) {
++ctl;
while (tp[ctl] == -1) ++ctl;
ntl = ctl + 1;
while (tp[ntl] == -1) ++ntl;
}
if (ctl == tp.length) return EMPTY;
final byte[] t = str.readBytes(ptok, ctl);
// skip pointer
size = str.read4(str.cursor() + 5);
// position will always fit in an integer...
ptok = (int) str.cursor();
return t;
}
/**
* Returns an iterator for an index entry.
*
* @param off offset on entries
* @param size number of id/pos entries
* @param da data source
* @param token index token
* @return iterator
*/
private static FTIndexIterator iter(
final long off, final int size, final DataAccess da, final byte[] token) {
da.cursor(off);
final IntList pr = new IntList(size);
final IntList ps = new IntList(size);
for (int c = 0; c < size; c++) {
pr.add(da.readNum());
ps.add(da.readNum());
}
return iter(new FTCache(pr, ps), token);
}