@Override
public synchronized int costs(final IndexToken it) {
final byte[] tok = it.get();
if (tok.length > data.meta.maxlen) return Integer.MAX_VALUE;
// estimate costs for queries which stretch over multiple index entries
final FTOpt opt = ((FTLexer) it).ftOpt();
if (opt.is(FZ) || opt.is(WC)) return Math.max(1, data.meta.size >> 4);
return entry(tok).size;
}
/**
* Prints the specified range of the table.
*
* @param data data reference
* @param s first node to be printed
* @param e last node to be printed
* @return table
*/
public static byte[] table(final Data data, final int s, final int e) {
final TokenBuilder tb = new TokenBuilder();
final int ps = Math.max(0, s);
final int pe = Math.min(data.meta.size, e);
final Table table = th();
for (int p = ps; p < pe; ++p) table(table, data, p);
tb.add(table.finish());
final byte[] ns = data.ns.table(ps, pe);
if (ns.length != 0) tb.add(NL).add(ns).add(data.ns.toString(ps, pe)).add(NL);
return tb.finish();
}
@Override
public DiskData build() throws IOException {
meta.assign(parser);
meta.dirty = true;
// calculate optimized output buffer sizes to reduce disk fragmentation
final Runtime rt = Runtime.getRuntime();
final long max = Math.min(1 << 22, rt.maxMemory() - rt.freeMemory() >> 2);
int bs = (int) Math.min(meta.filesize, max);
bs = Math.max(IO.BLOCKSIZE, bs - bs % IO.BLOCKSIZE);
// drop old database (if available) and create new one
DropDB.drop(dbname, sopts);
sopts.dbpath(dbname).md();
elemNames = new Names(meta);
attrNames = new Names(meta);
try {
tout = new DataOutput(new TableOutput(meta, DATATBL));
xout = new DataOutput(meta.dbfile(DATATXT), bs);
vout = new DataOutput(meta.dbfile(DATAATV), bs);
sout = new DataOutput(meta.dbfile(DATATMP), bs);
final Performance perf = Prop.debug ? new Performance() : null;
Util.debug(tit() + DOTS);
parse();
if (Prop.debug) Util.errln(" " + perf + " (" + Performance.getMemory() + ')');
} catch (final IOException ex) {
try {
close();
} catch (final IOException ignored) {
}
throw ex;
}
close();
// copy temporary values into database table
try (final DataInput in = new DataInput(meta.dbfile(DATATMP))) {
final TableAccess ta = new TableDiskAccess(meta, true);
for (; spos < ssize; ++spos) ta.write4(in.readNum(), 8, in.readNum());
ta.close();
}
meta.dbfile(DATATMP).delete();
// return database instance
return new DiskData(meta, elemNames, attrNames, path, ns);
}
/**
* Performs a fuzzy search for the specified token with a maximum number of errors.
*
* @param token token to look for
* @param k number of errors allowed
* @return iterator
*/
private synchronized IndexIterator fuzzy(final byte[] token, final int k) {
FTIndexIterator it = FTIndexIterator.FTEMPTY;
final int tokl = token.length, tl = tp.length;
final int e = Math.min(tl - 1, tokl + k);
int s = Math.max(1, tokl - k) - 1;
while (++s <= e) {
int p = tp[s];
if (p == -1) continue;
int t = s + 1, r = -1;
while (t < tl && r == -1) r = tp[t++];
while (p < r) {
if (ls.similar(inY.readBytes(p, s), token, k)) {
it = FTIndexIterator.union(iter(pointer(p, s), size(p, s), inZ, token), it);
}
p += s + ENTRY;
}
}
return it;
}
@Override
public void insert(final int pre, final byte[] entries) {
final int nnew = entries.length;
if (nnew == 0) return;
dirty();
// number of records to be inserted
final int nr = nnew >>> IO.NODEPOWER;
int split = 0;
if (used == 0) {
// special case: insert new data into first block if database is empty
readPage(0);
usedPages.set(0);
++used;
} else if (pre > 0) {
// find the offset within the block where the new records will be inserted
split = cursor(pre - 1) + IO.NODESIZE;
} else {
// all insert operations will add data after first node.
// i.e., there is no "insert before first document" statement
throw Util.notExpected("Insertion at beginning of populated table.");
}
// number of bytes occupied by old records in the current block
final int nold = npre - fpre << IO.NODEPOWER;
// number of bytes occupied by old records which will be moved at the end
final int moved = nold - split;
// special case: all entries fit in the current block
Buffer bf = bm.current();
if (nold + nnew <= IO.BLOCKSIZE) {
Array.move(bf.data, split, nnew, moved);
System.arraycopy(entries, 0, bf.data, split, nnew);
bf.dirty = true;
// increment first pre-values of blocks after the last modified block
for (int i = page + 1; i < used; ++i) fpres[i] += nr;
// update cached variables (fpre is not changed)
npre += nr;
meta.size += nr;
return;
}
// append old entries at the end of the new entries
final byte[] all = new byte[nnew + moved];
System.arraycopy(entries, 0, all, 0, nnew);
System.arraycopy(bf.data, split, all, nnew, moved);
// fill in the current block with new entries
// number of bytes which fit in the first block
int nrem = IO.BLOCKSIZE - split;
if (nrem > 0) {
System.arraycopy(all, 0, bf.data, split, nrem);
bf.dirty = true;
}
// number of new required blocks and remaining bytes
final int req = all.length - nrem;
int needed = req / IO.BLOCKSIZE;
final int remain = req % IO.BLOCKSIZE;
if (remain > 0) {
// check if the last entries can fit in the block after the current one
if (page + 1 < used) {
final int o = occSpace(page + 1) << IO.NODEPOWER;
if (remain <= IO.BLOCKSIZE - o) {
// copy the last records
readPage(page + 1);
bf = bm.current();
System.arraycopy(bf.data, 0, bf.data, remain, o);
System.arraycopy(all, all.length - remain, bf.data, 0, remain);
bf.dirty = true;
// reduce the pre value, since it will be later incremented with nr
fpres[page] -= remain >>> IO.NODEPOWER;
// go back to the previous block
readPage(page - 1);
} else {
// there is not enough space in the block - allocate a new one
++needed;
}
} else {
// this is the last block - allocate a new one
++needed;
}
}
// number of expected blocks: existing blocks + needed block - empty blocks
final int exp = blocks + needed - (blocks - used);
if (exp > fpres.length) {
// resize directory arrays if existing ones are too small
final int ns = Math.max(fpres.length << 1, exp);
fpres = Arrays.copyOf(fpres, ns);
pages = Arrays.copyOf(pages, ns);
}
// make place for the blocks where the new entries will be written
Array.move(fpres, page + 1, needed, used - page - 1);
Array.move(pages, page + 1, needed, used - page - 1);
// write the all remaining entries
while (needed-- > 0) {
freeBlock();
nrem += write(all, nrem);
fpres[page] = fpres[page - 1] + IO.ENTRIES;
pages[page] = (int) bm.current().pos;
}
// increment all fpre values after the last modified block
for (int i = page + 1; i < used; ++i) fpres[i] += nr;
meta.size += nr;
// update cached variables
fpre = fpres[page];
npre = page + 1 < used && fpres[page + 1] < meta.size ? fpres[page + 1] : meta.size;
}