package org.basex.query.item.map;
import static org.basex.query.QueryText.*;
import org.basex.query.QueryException;
import org.basex.query.item.AtomType;
import org.basex.query.item.Item;
import org.basex.query.item.SeqType;
import org.basex.query.item.Value;
import org.basex.query.iter.ItemCache;
import org.basex.util.Array;
import org.basex.util.InputInfo;
/**
* Leaf that contains a collision list of keys with the same hash code.
*
* @author BaseX Team 2005-12, BSD License
* @author Leo Woerteler
*/
final class List extends TrieNode {
/** Common hash value of all contained values. */
final int hash;
/** List of keys of this collision list. */
final Item[] keys;
/** List of values of this collision list. */
final Value[] values;
/**
* Constructor.
*
* @param h hash value
* @param ks key array
* @param vs value array
*/
List(final int h, final Item[] ks, final Value[] vs) {
super(ks.length);
keys = ks;
values = vs;
hash = h;
assert verify();
}
/**
* Constructor for creating a collision list from two bindings.
* @param h hash value
* @param k1 first key
* @param v1 first value
* @param k2 second key
* @param v2 second value
*/
List(final int h, final Item k1, final Value v1,
final Item k2, final Value v2) {
this(h, new Item[]{ k1, k2 }, new Value[]{ v1, v2 });
}
@Override
TrieNode delete(final int h, final Item k, final int l,
final InputInfo ii) throws QueryException {
if(h == hash) {
for(int i = size; i-- > 0;) {
if(eq(k, keys[i], ii)) {
// found entry
if(size == 2) {
// single leaf remains
final int o = i ^ 1;
return new Leaf(h, keys[o], values[o]);
}
// still collisions
return new List(h, Array.delete(keys, i), Array.delete(values, i));
}
}
}
return this;
}
@Override
TrieNode insert(final int h, final Item k, final Value v, final int l,
final InputInfo ii) throws QueryException {
// same hash, replace or merge
if(h == hash) {
for(int i = keys.length; i-- > 0;) {
if(eq(k, keys[i], ii)) {
// replace value
final Value[] vs = values.clone();
vs[i] = v;
return new List(h, keys.clone(), vs);
}
}
return new List(hash, Array.add(keys, k), Array.add(values, v));
}
// different hash, branch
final TrieNode[] ch = new TrieNode[KIDS];
final int a = key(h, l), b = key(hash, l);
final int used;
if(a != b) {
ch[a] = new Leaf(h, k, v);
ch[b] = this;
used = 1 << a | 1 << b;
} else {
ch[a] = insert(h, k, v, l + 1, ii);
used = 1 << a;
}
// we definitely inserted one value
return new Branch(ch, used, size + 1);
}
@Override
Value get(final int h, final Item k, final int l, final InputInfo ii)
throws QueryException {
if(h == hash) for(int i = keys.length; i-- != 0;)
if(eq(k, keys[i], ii)) return values[i];
return null;
}
@Override
boolean contains(final int h, final Item k, final int u, final InputInfo ii)
throws QueryException {
if(h == hash) for(int i = keys.length; i-- != 0;)
if(eq(k, keys[i], ii)) return true;
return false;
}
@Override
StringBuilder toString(final StringBuilder sb, final String ind) {
sb.append(ind).append("`-- Collision (").append(
Integer.toHexString(hash)).append("):\n");
for(int i = 0; i < keys.length; i++) {
sb.append(ind).append(" ").append(keys[i]).append(" => ").append(
values[i]).append('\n');
}
return sb;
}
@Override
TrieNode addAll(final TrieNode o, final int l, final InputInfo ii)
throws QueryException {
return o.add(this, l, ii);
}
@Override
TrieNode add(final Leaf o, final int l, final InputInfo ii)
throws QueryException {
if(hash == o.hash) {
for(final Item k : keys) if(eq(k, o.key, ii)) return this;
return new List(hash, Array.add(keys, o.key), Array.add(values, o.value));
}
final TrieNode[] ch = new TrieNode[KIDS];
final int k = key(hash, l), ok = key(o.hash, l);
final int nu;
// same key? add recursively
if(k == ok) {
ch[k] = add(o, l + 1, ii);
nu = 1 << k;
} else {
ch[k] = this;
ch[ok] = o;
nu = 1 << k | 1 << ok;
}
return new Branch(ch, nu, size + 1);
}
@Override
TrieNode add(final List o, final int l, final InputInfo ii)
throws QueryException {
if(hash == o.hash) {
Item[] ks = keys;
Value[] vs = values;
outer: for(int i = 0; i < size; i++) {
final Item ok = o.keys[i];
// skip all entries that are overridden
for(final Item k : keys) if(eq(k, ok, ii)) continue outer;
// key is not in this list, add it
ks = Array.add(ks, ok);
vs = Array.add(vs, o.values[i]);
}
return ks == keys ? this : new List(hash, ks, vs);
}
final TrieNode[] ch = new TrieNode[KIDS];
final int k = key(hash, l), ok = key(o.hash, l);
final int nu;
// same key? add recursively
if(k == ok) {
ch[k] = add(o, l + 1, ii);
nu = 1 << k;
} else {
ch[k] = this;
ch[ok] = o;
nu = 1 << k | 1 << ok;
}
return new Branch(ch, nu, size + o.size);
}
@Override
TrieNode add(final Branch o, final int l, final InputInfo ii)
throws QueryException {
final int k = key(hash, l);
final TrieNode[] ch = o.copyKids();
final TrieNode old = ch[k];
ch[k] = old == null ? this : old.addAll(this, l + 1, ii);
return new Branch(ch, o.used | 1 << k,
o.size + size - (old != null ? old.size : 0));
}
@Override
boolean verify() {
try {
for(int i = 1; i < size; i++) {
for(int j = i; j-- > 0;) {
if(eq(keys[i], keys[j], null)) return false;
}
}
} catch(final QueryException ex) {
return false;
}
return true;
}
@Override
void keys(final ItemCache ks) {
for(final Item k : keys) ks.add(k);
}
@Override
boolean hasType(final AtomType kt, final SeqType vt) {
if(kt != null)
for(final Item k : keys) if(!k.type.instanceOf(kt)) return false;
if(vt != null)
for(final Value v : values) if(!vt.instance(v)) return false;
return true;
}
@Override
int hash(final InputInfo ii) throws QueryException {
int h = hash;
// order isn't important, operation has to be commutative
for(int i = size; --i >= 0;) h ^= values[i].hash(ii);
return h;
}
@Override
boolean deep(final InputInfo ii, final TrieNode o) throws QueryException {
if(!(o instanceof List) || size != o.size) return false;
final List ol = (List) o;
// do the evil nested-loop thing
outer: for(int i = 0; i < size; i++) {
final Item k = keys[i];
for(int j = 0; j < size; j++) {
if(eq(k, ol.keys[i], ii)) {
// check bound value, too
if(!deep(values[i], ol.values[j], ii)) return false;
// value matched, continue with next key
continue outer;
}
}
// all keys of the other list were checked, none matched
return false;
}
// all entries were found
return true;
}
@Override
StringBuilder toString(final StringBuilder sb) {
for(int i = size; --i >= 0;)
sb.append(keys[i]).append(ASSIGN).append(values[i]).append(", ");
return sb;
}
}