/**
* Algorithm of Tarjan for computing the strongly connected components of a graph.
*
* @param v current node
* @throws QueryException if a variable directly calls itself
*/
private void tarjan(final int v) throws QueryException {
final int ixv = 2 * v, llv = ixv + 1, idx = next++;
while (list.size() <= llv) list.add(-1);
list.set(ixv, idx);
list.set(llv, idx);
stack.push(v);
for (final int w : adjacentTo(v)) {
final int ixw = 2 * w, llw = ixw + 1;
if (list.size() <= ixw || list.get(ixw) < 0) {
// Successor w has not yet been visited; recurse on it
tarjan(w);
list.set(llv, Math.min(list.get(llv), list.get(llw)));
} else if (stack.contains(w)) {
// Successor w is in stack S and hence in the current SCC
list.set(llv, Math.min(list.get(llv), list.get(ixw)));
}
}
// If v is a root node, pop the stack and generate an SCC
if (list.get(llv) == list.get(ixv)) {
int w;
Scope[] out = null;
do {
w = stack.pop();
final Scope scp = scopes.get(w);
out = out == null ? new Scope[] {scp} : Array.add(out, scp);
} while (w != v);
result.add(out);
}
}
/**
* Evaluates the full-text match.
*
* @param qc query context
* @return number of tokens, used for scoring
* @throws QueryException query exception
*/
private int contains(final QueryContext qc) throws QueryException {
first = true;
final FTLexer lexer = ftt.lexer(qc.ftToken);
// use faster evaluation for default options
int num = 0;
if (fast) {
for (final byte[] t : tokens) {
final FTTokens qtok = ftt.cache(t);
num = Math.max(num, ftt.contains(qtok, lexer) * qtok.length());
}
return num;
}
// find and count all occurrences
final boolean all = mode == FTMode.ALL || mode == FTMode.ALL_WORDS;
int oc = 0;
for (final byte[] w : unique(tokens(qc))) {
final FTTokens qtok = ftt.cache(w);
final int o = ftt.contains(qtok, lexer);
if (all && o == 0) return 0;
num = Math.max(num, o * qtok.length());
oc += o;
}
// check if occurrences are in valid range. if yes, return number of tokens
final long mn = occ != null ? toLong(occ[0], qc) : 1;
final long mx = occ != null ? toLong(occ[1], qc) : Long.MAX_VALUE;
if (mn == 0 && oc == 0) matches = FTNot.not(matches);
return oc >= mn && oc <= mx ? Math.max(1, num) : 0;
}
/**
* Returns a pre value.
*
* @param id unique node id
* @return pre value or -1 if id was not found
*/
final int preold(final int id) {
// find pre value in table
for (int p = Math.max(0, id); p < meta.size; ++p) if (id == id(p)) return p;
final int ps = Math.min(meta.size, id);
for (int p = 0; p < ps; ++p) if (id == id(p)) return p;
// id not found
return -1;
}
@Override
public boolean indexAccessible(final IndexInfo ii) {
/* If the following conditions yield true, the index is accessed:
* - all query terms are statically available
* - no FTTimes option is specified
* - explicitly set case, diacritics and stemming match options do not
* conflict with index options. */
data = ii.ic.data;
final MetaData md = data.meta;
final FTOpt fto = ftt.opt;
/* Index will be applied if no explicit match options have been set
* that conflict with the index options. As a consequence, though, index-
* based querying might yield other results than sequential scanning. */
if (occ != null
|| fto.cs != null && md.casesens == (fto.cs == FTCase.INSENSITIVE)
|| fto.isSet(DC) && md.diacritics != fto.is(DC)
|| fto.isSet(ST) && md.stemming != fto.is(ST)
|| fto.ln != null && !fto.ln.equals(md.language)) return false;
// adopt database options to tokenizer
fto.copy(md);
// estimate costs if text is not known at compile time
if (tokens == null) {
ii.costs = Math.max(2, data.meta.size / 30);
return true;
}
// summarize number of hits; break loop if no hits are expected
final FTLexer ft = new FTLexer(fto);
ii.costs = 0;
for (byte[] t : tokens) {
ft.init(t);
while (ft.hasNext()) {
final byte[] tok = ft.nextToken();
if (fto.sw != null && fto.sw.contains(tok)) continue;
if (fto.is(WC)) {
// don't use index if one of the terms starts with a wildcard
t = ft.get();
if (t[0] == '.') return false;
// don't use index if certain characters or more than 1 dot are found
int d = 0;
for (final byte w : t) {
if (w == '{' || w == '\\' || w == '.' && ++d > 1) return false;
}
}
// favor full-text index requests over exact queries
final int costs = data.costs(ft);
if (costs != 0) ii.costs += Math.max(2, costs / 100);
}
}
return true;
}
/**
* Adds an attribute entry to the internal update buffer.
*
* @param pre pre value
* @param dist parent distance
* @param name attribute name
* @param value attribute value
* @param uri namespace uri reference
* @param ne namespace flag
*/
public final void attr(
final int pre,
final int dist,
final int name,
final byte[] value,
final int uri,
final boolean ne) {
// add attribute to text storage
final int i = newID();
final long v = index(pre, i, value, ATTR);
final int n = ne ? 1 << 7 : 0;
s(Math.min(IO.MAXATTS, dist) << 3 | ATTR);
s(n | (byte) (name >> 8));
s(name);
s(v >> 32);
s(v >> 24);
s(v >> 16);
s(v >> 8);
s(v);
s(0);
s(0);
s(0);
s(uri);
s(i >> 24);
s(i >> 16);
s(i >> 8);
s(i);
}
/**
* Adds an element entry to the internal update buffer.
*
* @param dist parent distance
* @param name tag name index
* @param asize number of attributes
* @param size node size
* @param uri namespace uri reference
* @param ne namespace flag
*/
public final void elem(
final int dist,
final int name,
final int asize,
final int size,
final int uri,
final boolean ne) {
// build and insert new entry
final int i = newID();
final int n = ne ? 1 << 7 : 0;
s(Math.min(IO.MAXATTS, asize) << 3 | ELEM);
s(n | (byte) (name >> 8));
s(name);
s(uri);
s(dist >> 24);
s(dist >> 16);
s(dist >> 8);
s(dist);
s(size >> 24);
s(size >> 16);
s(size >> 8);
s(size);
s(i >> 24);
s(i >> 16);
s(i >> 8);
s(i);
}
/**
* Finds line and column for the specified query parser.
*
* @param parser parser
*/
void pos(final InputParser parser) {
markedCol = parser.mark;
if (info != null) return;
// check if line/column information has already been added
parser.pos = Math.min(parser.mark, parser.length);
info = new InputInfo(parser);
}
/**
* 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);
}
/**
* 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 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;
}
/**
* Retrieves and returns the whole text and closes the stream.
*
* @return contents
* @throws IOException I/O exception
*/
public byte[] content() throws IOException {
try {
if (length > 0) {
// input length is known in advance
final int sl = (int) Math.min(Integer.MAX_VALUE, length);
final byte[] bytes = new byte[sl];
for (int c = 0; c < sl; c++) bytes[c] = (byte) next();
return bytes;
}
// parse until end of stream
final ByteList bl = new ByteList();
for (int ch; (ch = next()) != -1; ) bl.add(ch);
return bl.toArray();
} finally {
close();
}
}
/**
* Inserts a data instance at the specified pre value. Note that the specified data instance must
* differ from this instance.
*
* @param ipre value at which to insert new data
* @param ipar parent pre value of node
* @param clip data clip
*/
public final void insert(final int ipre, final int ipar, final DataClip clip) {
meta.update();
// update value and document indexes
if (meta.updindex) indexBegin();
resources.insert(ipre, clip);
final int dsize = clip.size();
final int buf = Math.min(dsize, IO.BLOCKSIZE >> IO.NODEPOWER);
// resize buffer to cache more entries
buffer(buf);
// find all namespaces in scope to avoid duplicate declarations
final TokenMap nsScope = nspaces.scope(ipar, this);
// loop through all entries
final IntList preStack = new IntList();
final NSNode nsRoot = nspaces.current();
final HashSet<NSNode> newNodes = new HashSet<NSNode>();
final IntList flagPres = new IntList();
// indicates if database only contains a dummy node
final Data data = clip.data;
int c = 0;
for (int dpre = clip.start; dpre < clip.end; ++dpre, ++c) {
if (c != 0 && c % buf == 0) insert(ipre + c - buf);
final int pre = ipre + c;
final int dkind = data.kind(dpre);
final int dpar = data.parent(dpre, dkind);
// ipar < 0 if document nodes on top level are added
final int dis = dpar >= 0 ? dpre - dpar : ipar >= 0 ? pre - ipar : 0;
final int par = dis == 0 ? -1 : pre - dis;
if (c == 0) nspaces.root(par, this);
while (!preStack.isEmpty() && preStack.peek() > par) nspaces.close(preStack.pop());
switch (dkind) {
case DOC:
// add document
nspaces.prepare();
final int s = data.size(dpre, dkind);
doc(pre, s, data.text(dpre, true));
meta.ndocs++;
preStack.push(pre);
break;
case ELEM:
// add element
nspaces.prepare();
boolean ne = false;
if (data.nsFlag(dpre)) {
final Atts at = data.ns(dpre);
for (int a = 0; a < at.size(); ++a) {
// see if prefix has been declared/ is part of current ns scope
final byte[] old = nsScope.get(at.name(a));
if (old == null || !eq(old, at.value(a))) {
// we have to keep track of all new NSNodes that are added
// to the Namespace structure, as their pre values must not
// be updated. I.e. if an NSNode N with pre value 3 existed
// prior to inserting and two new nodes are inserted at
// location pre == 3 we have to make sure N and only N gets
// updated.
newNodes.add(nspaces.add(at.name(a), at.value(a), pre));
ne = true;
}
}
}
byte[] nm = data.name(dpre, dkind);
elem(
dis,
tagindex.index(nm, null, false),
data.attSize(dpre, dkind),
data.size(dpre, dkind),
nspaces.uri(nm, true),
ne);
preStack.push(pre);
break;
case TEXT:
case COMM:
case PI:
// add text
text(pre, dis, data.text(dpre, true), dkind);
break;
case ATTR:
// add attribute
nm = data.name(dpre, dkind);
// check if prefix already in nsScope or not
final byte[] attPref = prefix(nm);
// check if prefix of attribute has already been declared, otherwise
// add declaration to parent node
if (data.nsFlag(dpre) && nsScope.get(attPref) == null) {
nspaces.add(
par,
preStack.isEmpty() ? -1 : preStack.peek(),
attPref,
data.nspaces.uri(data.uri(dpre, dkind)),
this);
// save pre value to set ns flag later for this node. can't be done
// here as direct table access would interfere with the buffer
flagPres.add(par);
}
attr(
pre,
dis,
atnindex.index(nm, null, false),
data.text(dpre, false),
nspaces.uri(nm, false),
false);
break;
}
}
// finalize and update namespace structure
while (!preStack.isEmpty()) nspaces.close(preStack.pop());
nspaces.root(nsRoot);
if (bp != 0) insert(ipre + c - 1 - (c - 1) % buf);
// reset buffer to old size
buffer(1);
// set ns flags
for (int f = 0; f < flagPres.size(); f++) {
final int fl = flagPres.get(f);
table.write2(fl, 1, name(fl) | 1 << 15);
}
// increase size of ancestors
int p = ipar;
while (p >= 0) {
final int k = kind(p);
size(p, k, size(p, k) + dsize);
p = parent(p, k);
}
if (meta.updindex) {
// add the entries to the ID -> PRE mapping:
idmap.insert(ipre, id(ipre), dsize);
indexEnd();
}
if (!cache) updateDist(ipre + dsize, dsize);
// propagate PRE value shifts to namespaces
if (ipar != -1) nspaces.insert(ipre, dsize, newNodes);
}
/**
* Prints the current stack trace to System.err.
*
* @param i number of steps to print
*/
public static void stack(final int i) {
errln("You're here:");
final String[] stack = toArray(new Throwable());
final int l = Math.min(Math.max(2, i + 2), stack.length);
for (int s = 2; s < l; ++s) errln(stack[s]);
}
/**
* Formats the specified number and returns a string representation.
*
* @param item item
* @param pics pictures
* @param ii input info
* @return picture variables
* @throws QueryException query exception
*/
private byte[] format(final ANum item, final Picture[] pics, final InputInfo ii)
throws QueryException {
// Rule 1: return results for NaN
final double d = item.dbl(ii);
if (Double.isNaN(d)) return nan;
// Rule 2: check if value if negative (smaller than zero or -0)
final boolean neg = d < 0 || d == 0 && Double.doubleToLongBits(d) == Long.MIN_VALUE;
final Picture pic = pics[neg && pics.length == 2 ? 1 : 0];
final IntList res = new IntList(), intgr = new IntList(), fract = new IntList();
int exp = 0;
// Rule 3: percent/permille
ANum num = item;
if (pic.pc) num = (ANum) Calc.MULT.ev(num, Int.get(100), ii);
if (pic.pm) num = (ANum) Calc.MULT.ev(num, Int.get(1000), ii);
if (Double.isInfinite(num.dbl(ii))) {
// Rule 4: infinity
intgr.add(new TokenParser(inf).toArray());
} else {
// Rule 5: exponent
if (pic.minExp != 0 && d != 0) {
BigDecimal dec = num.dec(ii).abs().stripTrailingZeros();
int scl = 0;
if (dec.compareTo(BigDecimal.ONE) >= 0) {
scl = dec.setScale(0, RoundingMode.HALF_DOWN).precision();
} else {
while (dec.compareTo(BigDecimal.ONE) < 0) {
dec = dec.multiply(BigDecimal.TEN);
scl--;
}
scl++;
}
exp = scl - pic.min[0];
if (exp != 0) {
final BigDecimal n = BigDecimal.TEN.pow(Math.abs(exp));
num = (ANum) Calc.MULT.ev(num, Dec.get(exp > 0 ? BigDecimal.ONE.divide(n) : n), ii);
}
}
num = num.round(pic.maxFrac, true).abs();
// convert positive number to string
final String s =
(num instanceof Dbl || num instanceof Flt
? Dec.get(BigDecimal.valueOf(num.dbl(ii)))
: num)
.toString();
// integer/fractional separator
final int sep = s.indexOf('.');
// create integer part
final int sl = s.length();
final int il = sep == -1 ? sl : sep;
for (int i = il; i < pic.min[0]; ++i) intgr.add(zero);
// fractional number: skip leading 0
if (!s.startsWith("0.") || pic.min[0] > 0) {
for (int i = 0; i < il; i++) intgr.add(zero + s.charAt(i) - '0');
}
// squeeze in grouping separators
if (pic.group[0].length == 1 && pic.group[0][0] > 0) {
// regular pattern with repeating separators
for (int p = intgr.size() - (neg ? 2 : 1); p > 0; --p) {
if (p % pic.group[0][0] == 0) intgr.insert(intgr.size() - p, grouping);
}
} else {
// irregular pattern, or no separators at all
final int gl = pic.group[0].length;
for (int g = 0; g < gl; ++g) {
final int pos = intgr.size() - pic.group[0][g];
if (pos > 0) intgr.insert(pos, grouping);
}
}
// create fractional part
final int fl = sep == -1 ? 0 : sl - il - 1;
if (fl != 0) for (int i = sep + 1; i < sl; i++) fract.add(zero + s.charAt(i) - '0');
for (int i = fl; i < pic.min[1]; ++i) fract.add(zero);
// squeeze in grouping separators in a reverse manner
final int ul = fract.size();
for (int p = pic.group[1].length - 1; p >= 0; p--) {
final int pos = pic.group[1][p];
if (pos < ul) fract.insert(pos, grouping);
}
}
// add minus sign
if (neg && pics.length != 2) res.add(minus);
// add prefix and integer part
res.add(pic.prefSuf[0].toArray()).add(intgr.finish());
// add fractional part
if (!fract.isEmpty()) res.add(decimal).add(fract.finish());
// add exponent
if (pic.minExp != 0) {
res.add(exponent);
if (exp < 0) res.add(minus);
final String s = Integer.toString(Math.abs(exp));
final int sl = s.length();
for (int i = sl; i < pic.minExp; i++) res.add(zero);
for (int i = 0; i < sl; i++) res.add(zero + s.charAt(i) - '0');
}
// add suffix
res.add(pic.prefSuf[1].toArray());
return new TokenBuilder(res.finish()).finish();
}
/**
* Analyzes the specified patterns.
*
* @param patterns patterns
* @return picture variables
*/
private Picture[] analyze(final byte[][] patterns) {
// pictures
final int picL = patterns.length;
final Picture[] pics = new Picture[picL];
// analyze patterns
for (int p = 0; p < picL; p++) {
final byte[] pt = patterns[p];
final Picture pic = new Picture();
// position (integer/fractional)
int pos = 0;
// active character found
boolean act = false;
// number of characters after exponent
int exp = -1;
// number of optional characters
final int[] opt = new int[2];
// loop through all characters
final int pl = pt.length;
for (int i = 0, cl; i < pl; i += cl) {
final int ch = ch(pt, i);
cl = cl(pt, i);
boolean active = contains(actives, ch);
if (ch == decimal) {
++pos;
act = false;
} else if (ch == optional) {
opt[pos]++;
} else if (ch == exponent) {
if (act && containsActive(pt, i + cl)) {
exp = 0;
} else {
active = false;
}
} else if (ch == grouping) {
if (pos == 0) pic.group[pos] = Array.add(pic.group[pos], pic.min[pos] + opt[pos]);
} else if (contains(digits, ch)) {
if (exp == -1) pic.min[pos]++;
else exp++;
}
if (active) {
act = true;
} else {
// passive characters
pic.pc |= ch == percent;
pic.pm |= ch == permille;
// prefixes/suffixes
pic.prefSuf[pos == 0 && act ? pos + 1 : pos].add(ch);
}
}
// finalize integer-part-grouping-positions
final int[] igp = pic.group[0];
final int igl = igp.length;
for (int g = 0; g < igl; ++g) igp[g] = pic.min[0] + opt[0] - igp[g];
// check if integer-part-grouping-positions are regular
// if yes, they are replaced with a single position
if (igl > 1) {
boolean reg = true;
final int i = igp[igl - 1];
for (int g = igl - 2; g >= 0; --g) reg &= i * igl == igp[g];
if (reg) pic.group[0] = new int[] {i};
}
pic.maxFrac = pic.min[1] + opt[1];
pic.minExp = Math.max(0, exp);
pics[p] = pic;
}
return pics;
}
