/**
* Optimizes descendant-or-self steps and static types.
*
* @param ctx query context
*/
void optSteps(final QueryContext ctx) {
boolean opt = false;
Expr[] st = steps;
for (int l = 1; l < st.length; ++l) {
if (!(st[l - 1] instanceof Step && st[l] instanceof Step)) continue;
final Step prev = (Step) st[l - 1];
final Step curr = (Step) st[l];
if (!prev.simple(DESCORSELF, false)) continue;
if (curr.axis == CHILD && !curr.has(Flag.FCS)) {
// descendant-or-self::node()/child::X -> descendant::X
final int sl = st.length;
final Expr[] tmp = new Expr[sl - 1];
System.arraycopy(st, 0, tmp, 0, l - 1);
System.arraycopy(st, l, tmp, l - 1, sl - l);
st = tmp;
curr.axis = DESC;
opt = true;
} else if (curr.axis == ATTR && !curr.has(Flag.FCS)) {
// descendant-or-self::node()/@X -> descendant-or-self::*/@X
prev.test = new NameTest(false);
opt = true;
}
}
if (opt) ctx.compInfo(OPTDESC);
// set atomic type for single attribute steps to speedup predicate tests
if (root == null && st.length == 1 && st[0] instanceof Step) {
final Step curr = (Step) st[0];
if (curr.axis == ATTR && curr.test.mode == Mode.STD) curr.type = SeqType.NOD_ZO;
}
steps = st;
}
/**
* Fill the current buffer with bytes from the specified array from the specified offset.
*
* @param s source array
* @param o offset from the beginning of the array
* @return number of written bytes
*/
private int write(final byte[] s, final int o) {
final Buffer bf = bm.current();
final int len = Math.min(IO.BLOCKSIZE, s.length - o);
System.arraycopy(s, o, bf.data, 0, len);
bf.dirty = true;
return len;
}
@Override
protected void copy(final byte[] entries, final int pre, final int last) {
for (int o = 0, i = pre; i < last; ++i, o += IO.NODESIZE) {
final int off = cursor(i);
final Buffer bf = bm.current();
System.arraycopy(entries, o, bf.data, off, IO.NODESIZE);
bf.dirty = true;
}
}
/**
* Sets the output text.
*
* @param out cached output
*/
public void setText(final ArrayOutput out) {
final byte[] buf = out.buffer();
final int size = (int) out.size();
final byte[] chop = token(DOTS);
if (out.finished() && size >= chop.length) {
System.arraycopy(chop, 0, buf, size - chop.length, chop.length);
}
text.setText(buf, size);
header.setText((out.finished() ? CHOPPED : "") + RESULT);
home.setEnabled(gui.context.data() != null);
}
/**
* Indexes the specified name and its kind.
*
* @param nm name id
* @param knd node kind
* @param value value
* @param meta meta data
* @return node reference
*/
PathNode index(final int nm, final byte knd, final byte[] value, final MetaData meta) {
for (final PathNode c : children) {
if (c.kind == knd && c.name == nm) {
if (value != null) c.stats.add(value, meta);
c.stats.count++;
return c;
}
}
final PathNode node = new PathNode(nm, knd, this);
if (value != null) node.stats.add(value, meta);
final int cs = children.length;
final PathNode[] nodes = new PathNode[cs + 1];
System.arraycopy(children, 0, nodes, 0, cs);
nodes[cs] = node;
children = nodes;
return node;
}
/**
* Adds values to the index.
*
* @param key key to be indexed
* @param vals sorted values
*/
void add(final byte[] key, final int... vals) {
// token index: add values. otherwise, reference existing values
final int id = type == IndexType.TOKEN ? values.put(key) : values.id(key), vl = vals.length;
// updatable index: if required, resize existing arrays
while (idsList.size() < id + 1) idsList.add(null);
if (lenList.size() < id + 1) lenList.set(id, 0);
final int len = lenList.get(id), size = len + vl;
int[] ids = idsList.get(id);
if (ids == null) {
ids = vals;
} else {
if (ids.length < size) ids = Arrays.copyOf(ids, Array.newSize(size));
System.arraycopy(vals, 0, ids, len, vl);
if (ids[len - 1] > vals[0]) {
if (reorder == null) reorder = new BoolList(values.size());
reorder.set(id, true);
}
}
idsList.set(id, ids);
lenList.set(id, size);
}
/**
* Convenience method for copying blocks.
*
* @param s source array
* @param sp source position
* @param d destination array
* @param dp destination position
* @param l source length
*/
private void copy(final byte[] s, final int sp, final byte[] d, final int dp, final int l) {
System.arraycopy(s, sp << IO.NODEPOWER, d, dp << IO.NODEPOWER, l << IO.NODEPOWER);
bm.current().dirty = true;
}
@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;
}
