@Override
public final Expr compile(final QueryContext qc, final VarScope scp) throws QueryException {
if (root != null) root = root.compile(qc, scp);
// no steps
if (steps.length == 0) return root == null ? new Context(info) : root;
final Value init = qc.value, cv = initial(qc);
final boolean doc = cv != null && cv.type == NodeType.DOC;
qc.value = cv;
try {
final int sl = steps.length;
for (int s = 0; s < sl; s++) {
Expr e = steps[s];
// axis step: if input is a document, its type is temporarily generalized
final boolean as = e instanceof Step;
if (as && s == 0 && doc) cv.type = NodeType.NOD;
e = e.compile(qc, scp);
if (e.isEmpty()) return optPre(qc);
steps[s] = e;
// no axis step: invalidate context value
if (!as) qc.value = null;
}
} finally {
if (doc) cv.type = NodeType.DOC;
qc.value = init;
}
// optimize path
return optimize(qc, scp);
}
@Override
public final Expr optimize(final QueryContext qc, final VarScope scp) throws QueryException {
final Value v = initial(qc);
if (v != null && v.isEmpty() || emptyPath(v)) return optPre(qc);
// merge descendant steps
Expr e = mergeSteps(qc);
if (e == this && v != null && v.type == NodeType.DOC) {
// check index access
e = index(qc, v);
// rewrite descendant to child steps
if (e == this) e = children(qc, v);
}
// recompile path if it has changed
if (e != this) return e.compile(qc, scp);
// set atomic type for single attribute steps to speed up predicate tests
if (root == null && steps.length == 1 && steps[0] instanceof Step) {
final Step curr = (Step) steps[0];
if (curr.axis == ATTR && curr.test.kind == Kind.URI_NAME) curr.seqType(SeqType.NOD_ZO);
}
// choose best path implementation and set type information
final Path path = get(info, root, steps);
path.size = path.size(qc);
path.seqType = SeqType.get(steps[steps.length - 1].seqType().type, size);
return path;
}
/**
* Computes the number of results.
*
* @param qc query context (may be @code null)
* @return number of results
*/
private long size(final QueryContext qc) {
final Value rt = initial(qc);
// skip computation if value is not a document node
if (rt == null || rt.type != NodeType.DOC) return -1;
final Data data = rt.data();
// skip computation if no database instance is available, is out-of-date or
// if context does not contain all database nodes
if (data == null || !data.meta.uptodate || data.resources.docs().size() != rt.size()) return -1;
ArrayList<PathNode> nodes = data.paths.root();
long m = 1;
final int sl = steps.length;
for (int s = 0; s < sl; s++) {
final Step curr = axisStep(s);
if (curr != null) {
nodes = curr.nodes(nodes, data);
if (nodes == null) return -1;
} else if (s + 1 == sl) {
m = steps[s].size();
} else {
// stop if a non-axis step is not placed last
return -1;
}
}
long sz = 0;
for (final PathNode pn : nodes) sz += pn.stats.count;
return sz * m;
}
@Override
public Value value(final QueryContext ctx) throws QueryException {
final int o = (int) ctx.resources.output.size();
final Updates updates = ctx.resources.updates();
final ContextModifier tmp = updates.mod;
final TransformModifier pu = new TransformModifier();
updates.mod = pu;
try {
for (final Let fo : copies) {
final Iter ir = ctx.iter(fo.expr);
Item i = ir.next();
if (!(i instanceof ANode) || ir.next() != null) throw UPCOPYMULT.get(fo.info, fo.var.name);
// copy node to main memory data instance
i = ((ANode) i).dbCopy(ctx.context.options);
// add resulting node to variable
ctx.set(fo.var, i, info);
pu.addData(i.data());
}
final Value v = ctx.value(expr[0]);
if (!v.isEmpty()) throw BASEX_MOD.get(info);
updates.prepare();
updates.apply();
return ctx.value(expr[1]);
} finally {
ctx.resources.output.size(o);
updates.mod = tmp;
}
}
/**
* Test sending of HTTP GET requests.
*
* @throws Exception exception
*/
@Test
public void postGet() throws Exception {
// GET1 - just send a GET request
try (final QueryProcessor qp =
new QueryProcessor(
_HTTP_SEND_REQUEST.args("<http:request method='get' href='" + REST_ROOT + "'/>"),
ctx)) {
final Value v = qp.value();
checkResponse(v, 2, HttpURLConnection.HTTP_OK);
assertEquals(NodeType.DOC, v.itemAt(1).type);
}
// GET2 - with override-media-type='text/plain'
try (final QueryProcessor qp =
new QueryProcessor(
_HTTP_SEND_REQUEST.args(
"<http:request method='get' override-media-type='text/plain'/>", REST_ROOT),
ctx)) {
final Value v = qp.value();
checkResponse(v, 2, HttpURLConnection.HTTP_OK);
assertEquals(AtomType.STR, v.itemAt(1).type);
}
// Get3 - with status-only='true'
try (final QueryProcessor qp =
new QueryProcessor(
_HTTP_SEND_REQUEST.args("<http:request method='get' status-only='true'/>", REST_ROOT),
ctx)) {
checkResponse(qp.value(), 1, HttpURLConnection.HTTP_OK);
}
}
/**
* Returns a string representation of all found arguments.
*
* @param args array with arguments
* @return string representation
*/
static String foundArgs(final Value[] args) {
// compose found arguments
final StringBuilder sb = new StringBuilder();
for (final Value v : args) {
if (sb.length() != 0) sb.append(", ");
sb.append(v instanceof Jav ? Util.className(((Jav) v).toJava()) : v.seqType());
}
return sb.toString();
}
/**
* Checks the response to an HTTP request.
*
* @param v query result
* @param itemsCount expected number of items
* @param expStatus expected status
*/
private static void checkResponse(final Value v, final int itemsCount, final int expStatus) {
assertEquals(itemsCount, v.size());
assertTrue(v.itemAt(0) instanceof FElem);
final FElem response = (FElem) v.itemAt(0);
assertNotNull(response.attributes());
if (!eq(response.attribute(STATUS), token(expStatus))) {
fail("Expected: " + expStatus + "\nFound: " + response);
}
}
/**
* Returns the root of the current context or {@code null}.
*
* @param ctx query context
* @return root
*/
final Value root(final QueryContext ctx) {
final Value v = ctx != null ? ctx.value : null;
// no root specified: return context, if it does not reference a document
// as e.g. happens in //a(b|c)
if (root == null) return v == null || v.type != NodeType.DOC ? v : null;
// root is value: return root
if (root.isValue()) return (Value) root;
// no root reference, no context: return null
if (!(root instanceof Root) || v == null) return null;
// return context sequence or root of current context
return v.size() == 1 ? Root.root(v) : v;
}
@Override
public Expr compile(final QueryContext qc, final VarScope scp) throws QueryException {
final Value init = qc.value;
// never compile predicates with empty sequence as context value (#1016)
if (init != null && init.isEmpty()) qc.value = null;
try {
final int pl = preds.length;
for (int p = 0; p < pl; ++p) preds[p] = preds[p].compile(qc, scp).optimizeEbv(qc, scp);
return this;
} finally {
qc.value = init;
}
}
/**
* Returns a parameter.
*
* @param value value
* @param name name
* @param declared variable declaration flags
* @return parameter
* @throws QueryException HTTP exception
*/
private RestXqParam param(final Value value, final QNm name, final boolean[] declared)
throws QueryException {
// [CG] RESTXQ: allow identical field names?
final long vs = value.size();
if (vs < 2) error(ANN_PARAMS, "%", name.string(), 2);
// name of parameter
final String key = toString(value.itemAt(0), name);
// variable template
final QNm qnm = checkVariable(toString(value.itemAt(1), name), declared);
// default value
final ValueBuilder vb = new ValueBuilder();
for (int v = 2; v < vs; v++) vb.add(value.itemAt(v));
return new RestXqParam(qnm, key, vb.value());
}
/**
* Returns the path nodes that will result from this path.
*
* @param qc query context
* @return path nodes, or {@code null} if nodes cannot be evaluated
*/
public final ArrayList<PathNode> pathNodes(final QueryContext qc) {
final Value init = initial(qc);
final Data data = init != null && init.type == NodeType.DOC ? init.data() : null;
if (data == null || !data.meta.uptodate) return null;
ArrayList<PathNode> nodes = data.paths.root();
final int sl = steps.length;
for (int s = 0; s < sl; s++) {
final Step curr = axisStep(s);
if (curr == null) return null;
nodes = curr.nodes(nodes, data);
if (nodes == null) return null;
}
return nodes;
}
/**
* Builds the thesaurus.
*
* @param value input nodes
* @throws QueryException query exception
*/
private void build(final Value value) throws QueryException {
final Value synonyms = nodes("*:synonym", value);
if (synonyms.isEmpty()) return;
final ThesNode term = node(text("*:term", value));
for (final Item synonym : synonyms) {
final ThesNode sterm = node(text("*:term", synonym));
final byte[] rs = text("*:relationship", synonym);
term.add(sterm, rs);
final byte[] srs = RSHIPS.get(rs);
if (srs != null) sterm.add(term, srs);
build(synonyms);
}
}
@Override
protected Expr opt(final CompileContext cc) throws QueryException {
if (allAreValues() && exprs[0].size() < UNROLL_LIMIT) {
// unroll the loop
cc.info(QueryText.OPTUNROLL_X, this);
final Value seq = (Value) exprs[0];
final int len = (int) seq.size();
// fn:for-each(...)
final Expr[] results = new Expr[len];
for (int i = 0; i < len; i++) {
results[i] = new DynFuncCall(info, sc, exprs[1], seq.itemAt(i)).optimize(cc);
}
return new List(info, results).optimize(cc);
}
return this;
}
/**
* Converts descendant to child steps.
*
* @param qc query context
* @param rt root value
* @return original or new expression
*/
private Expr children(final QueryContext qc, final Value rt) {
// skip if index does not exist or is out-dated, or if several namespaces occur in the input
final Data data = rt.data();
if (data == null || !data.meta.uptodate || data.nspaces.globalNS() == null) return this;
Path path = this;
final int sl = steps.length;
for (int s = 0; s < sl; s++) {
// don't allow predicates in preceding location steps
final Step prev = s > 0 ? axisStep(s - 1) : null;
if (prev != null && prev.preds.length != 0) break;
// ignore axes other than descendant, or numeric predicates
final Step curr = axisStep(s);
if (curr == null || curr.axis != DESC || curr.has(Flag.FCS)) continue;
// check if child steps can be retrieved for current step
ArrayList<PathNode> nodes = pathNodes(data, s);
if (nodes == null) continue;
// cache child steps
final ArrayList<QNm> qnm = new ArrayList<>();
while (nodes.get(0).parent != null) {
QNm nm = new QNm(data.elemNames.key(nodes.get(0).name));
// skip children with prefixes
if (nm.hasPrefix()) return this;
for (final PathNode p : nodes) {
if (nodes.get(0).name != p.name) nm = null;
}
qnm.add(nm);
nodes = PathSummary.parent(nodes);
}
qc.compInfo(OPTCHILD, steps[s]);
// build new steps
int ts = qnm.size();
final Expr[] stps = new Expr[ts + sl - s - 1];
for (int t = 0; t < ts; t++) {
final Expr[] preds = t == ts - 1 ? ((Preds) steps[s]).preds : new Expr[0];
final QNm nm = qnm.get(ts - t - 1);
final NameTest nt =
nm == null ? new NameTest(false) : new NameTest(nm, Kind.NAME, false, null);
stps[t] = Step.get(info, CHILD, nt, preds);
}
while (++s < sl) stps[ts++] = steps[s];
path = get(info, root, stps);
break;
}
// check if all steps yield results; if not, return empty sequence
final ArrayList<PathNode> nodes = pathNodes(qc);
if (nodes != null && nodes.isEmpty()) {
qc.compInfo(OPTPATH, path);
return Empty.SEQ;
}
return path;
}
/**
* Evaluates the specified query.
*
* @param query query
* @return success flag
*/
final boolean query(final String query) {
final Performance p = new Performance();
String error;
if (exception != null) {
error = Util.message(exception);
} else {
try {
long hits = 0;
final boolean run = options.get(MainOptions.RUNQUERY);
final boolean serial = options.get(MainOptions.SERIALIZE);
final int runs = Math.max(1, options.get(MainOptions.RUNS));
for (int r = 0; r < runs; ++r) {
// reuse existing processor instance
if (r != 0) qp = null;
qp(query, context);
parse(p);
if (r == 0) plan(false);
qp.compile();
info.compiling += p.time();
if (r == 0) plan(true);
if (!run) continue;
final PrintOutput po = r == 0 && serial ? out : new NullOutput();
try (final Serializer ser = qp.getSerializer(po)) {
if (maxResults >= 0) {
result = qp.cache(maxResults);
info.evaluating += p.time();
result.serialize(ser);
hits = result.size();
} else {
hits = 0;
final Iter ir = qp.iter();
info.evaluating += p.time();
for (Item it; (it = ir.next()) != null; ) {
ser.serialize(it);
++hits;
checkStop();
}
}
}
qp.close();
info.serializing += p.time();
}
// dump some query info
// out.flush();
// remove string list if global locking is used and if query is updating
if (soptions.get(StaticOptions.GLOBALLOCK) && qp.updating) {
info.readLocked = null;
info.writeLocked = null;
}
return info(info.toString(qp, out.size(), hits, options.get(MainOptions.QUERYINFO)));
} catch (final QueryException | IOException ex) {
exception = ex;
error = Util.message(ex);
} catch (final ProcException ex) {
error = INTERRUPTED;
} catch (final StackOverflowError ex) {
Util.debug(ex);
error = BASX_STACKOVERFLOW.desc;
} catch (final RuntimeException ex) {
extError("");
Util.debug(info());
throw ex;
} finally {
// close processor after exceptions
if (qp != null) qp.close();
}
}
return extError(error);
}
/**
* Checks a function for RESTFful annotations.
*
* @return {@code true} if module contains relevant annotations
* @throws QueryException query exception
*/
boolean analyze() throws QueryException {
// parse all annotations
final EnumSet<HTTPMethod> mth = EnumSet.noneOf(HTTPMethod.class);
final boolean[] declared = new boolean[function.args.length];
boolean found = false;
final int as = function.ann.size();
for (int a = 0; a < as; a++) {
final QNm name = function.ann.names[a];
final Value value = function.ann.values[a];
final byte[] local = name.local();
final byte[] uri = name.uri();
final boolean rexq = eq(uri, QueryText.RESTXQURI);
if (rexq) {
if (eq(PATH, local)) {
// annotation "path"
if (path != null) error(ANN_TWICE, "%", name.string());
path = new RestXqPath(toString(value, name));
for (final String s : path) {
if (s.trim().startsWith("{")) checkVariable(s, AtomType.AAT, declared);
}
} else if (eq(CONSUMES, local)) {
// annotation "consumes"
strings(value, name, consumes);
} else if (eq(PRODUCES, local)) {
// annotation "produces"
strings(value, name, produces);
} else if (eq(QUERY_PARAM, local)) {
// annotation "query-param"
queryParams.add(param(value, name, declared));
} else if (eq(FORM_PARAM, local)) {
// annotation "form-param"
formParams.add(param(value, name, declared));
} else if (eq(HEADER_PARAM, local)) {
// annotation "header-param"
headerParams.add(param(value, name, declared));
} else if (eq(COOKIE_PARAM, local)) {
// annotation "cookie-param"
cookieParams.add(param(value, name, declared));
} else {
// method annotations
final HTTPMethod m = HTTPMethod.get(string(local));
if (m == null) error(ANN_UNKNOWN, "%", name.string());
if (!value.isEmpty()) {
// remember post/put variable
if (requestBody != null) error(ANN_TWICE, "%", name.string());
if (m != POST && m != PUT) error(METHOD_VALUE, m);
requestBody = checkVariable(toString(value, name), declared);
}
if (mth.contains(m)) error(ANN_TWICE, "%", name.string());
mth.add(m);
}
} else if (eq(uri, QueryText.OUTPUTURI)) {
// serialization parameters
final String key = string(local);
final String val = toString(value, name);
if (output.get(key) == null) error(UNKNOWN_SER, key);
output.set(key, val);
}
found |= rexq;
}
if (!mth.isEmpty()) methods = mth;
if (found) {
if (path == null) error(ANN_MISSING, PATH);
for (int i = 0; i < declared.length; i++)
if (!declared[i]) error(VAR_UNDEFINED, function.args[i].name.string());
}
return found;
}
/**
* Returns an equivalent expression which accesses an index. If the expression cannot be
* rewritten, the original expression is returned.
*
* <p>The following types of queries can be rewritten (in the examples, the equality comparison is
* used, which will be rewritten to {@link ValueAccess} instances):
*
* <pre>
* 1. A[text() = '...'] -> IA('...')
* 2. A[. = '...'] -> IA('...', A)
* 3. text()[. = '...'] -> IA('...')
* 4. A[B = '...'] -> IA('...', B)/parent::A
* 1. A[B/text() = '...'] -> IA('...')/parent::B/parent::A
* 2. A[B/C = '...'] -> IA('...', C)/parent::B/parent::A
* 7. A[@a = '...'] -> IA('...', @a)/parent::A
* 8. @a[. = '...'] -> IA('...', @a)</pre>
*
* Queries of type 1, 3, 5 will not yield any results if the string to be compared is empty.
*
* @param qc query context
* @param rt root value
* @return original or new expression
* @throws QueryException query exception
*/
private Expr index(final QueryContext qc, final Value rt) throws QueryException {
// only rewrite paths with data reference
final Data data = rt.data();
if (data == null) return this;
// cache index access costs
IndexInfo index = null;
// cheapest predicate and step
int iPred = 0, iStep = 0;
// check if path can be converted to an index access
final int sl = steps.length;
for (int s = 0; s < sl; s++) {
// only accept descendant steps without positional predicates
final Step step = axisStep(s);
if (step == null || !step.axis.down || step.has(Flag.FCS)) break;
// check if path is iterable (i.e., will be duplicate-free)
final boolean iter = pathNodes(data, s) != null;
final IndexContext ictx = new IndexContext(data, iter);
// choose cheapest index access
final int pl = step.preds.length;
for (int p = 0; p < pl; p++) {
final IndexInfo ii = new IndexInfo(ictx, qc, step);
if (!step.preds[p].indexAccessible(ii)) continue;
if (ii.costs == 0) {
// no results...
qc.compInfo(OPTNOINDEX, this);
return Empty.SEQ;
}
if (index == null || index.costs > ii.costs) {
index = ii;
iPred = p;
iStep = s;
}
}
}
// skip rewriting if no index access is possible, or if it is too expensive
if (index == null || index.costs > data.meta.size) return this;
// rewrite for index access
qc.compInfo(index.info);
// replace expressions for index access
final Step indexStep = index.step;
// collect remaining predicates
final int pl = indexStep.preds.length;
final ExprList newPreds = new ExprList(pl - 1);
for (int p = 0; p < pl; p++) {
if (p != iPred) newPreds.add(indexStep.preds[p]);
}
// invert steps that occur before index step and add them as predicate
final Test test = InvDocTest.get(rt);
final ExprList invSteps = new ExprList();
if (test != Test.DOC || !data.meta.uptodate || predSteps(data, iStep)) {
for (int s = iStep; s >= 0; s--) {
final Axis ax = axisStep(s).axis.invert();
if (s == 0) {
// add document test for collections and axes other than ancestors
if (test != Test.DOC || ax != Axis.ANC && ax != Axis.ANCORSELF)
invSteps.add(Step.get(info, ax, test));
} else {
final Step prev = axisStep(s - 1);
invSteps.add(Step.get(info, ax, prev.test, prev.preds));
}
}
}
if (!invSteps.isEmpty()) newPreds.add(get(info, null, invSteps.finish()));
// create resulting expression
final ExprList resultSteps = new ExprList();
final Expr resultRoot;
if (index.expr instanceof Path) {
final Path p = (Path) index.expr;
resultRoot = p.root;
resultSteps.add(p.steps);
} else {
resultRoot = index.expr;
}
if (!newPreds.isEmpty()) {
int ls = resultSteps.size() - 1;
Step step;
if (ls < 0 || !(resultSteps.get(ls) instanceof Step)) {
// add at least one self axis step
step = Step.get(info, Axis.SELF, Test.NOD);
ls++;
} else {
step = (Step) resultSteps.get(ls);
}
// add remaining predicates to last step
resultSteps.set(ls, step.addPreds(newPreds.finish()));
}
// add remaining steps
for (int s = iStep + 1; s < sl; s++) resultSteps.add(steps[s]);
return get(info, resultRoot, resultSteps.finish());
}
/**
* Adds items to the specified list.
*
* @param value value
* @param name name
* @param list list to add values to
* @throws QueryException HTTP exception
*/
private void strings(final Value value, final QNm name, final StringList list)
throws QueryException {
final long vs = value.size();
for (int v = 0; v < vs; v++) list.add(toString(value.itemAt(v), name));
}
@Override
public Value value(final QueryContext qc) throws QueryException {
final Value val = qc.value(exprs[0]);
if (val.isEmpty()) throw ONEORMORE.get(info);
return val;
}