/**
* This class is an entry point for evaluating XQuery strings.
*
* @author BaseX Team 2005-16, BSD License
* @author Christian Gruen
*/
public final class QueryProcessor extends Job implements Closeable {
/** Pattern for detecting library modules. */
private static final Pattern LIBMOD_PATTERN =
Pattern.compile(
"^(xquery( version ['\"].*?['\"])?( encoding ['\"].*?['\"])? ?; ?)?module namespace.*");
/** Static context. */
public final StaticContext sc;
/** Expression context. */
public final QueryContext qc;
/** Query. */
private final String query;
/** Parsed flag. */
private boolean parsed;
/**
* Default constructor.
*
* @param query query string
* @param ctx database context
*/
public QueryProcessor(final String query, final Context ctx) {
this(query, null, ctx);
}
/**
* Default constructor.
*
* @param query query string
* @param uri base uri (can be {@code null})
* @param ctx database context
*/
public QueryProcessor(final String query, final String uri, final Context ctx) {
this.query = query;
qc = pushJob(new QueryContext(ctx));
sc = new StaticContext(qc);
sc.baseURI(uri);
}
/**
* Parses the query.
*
* @throws QueryException query exception
*/
public void parse() throws QueryException {
if (parsed) return;
try {
qc.parseMain(query, null, sc);
} finally {
parsed = true;
updating = qc.updating;
}
}
/**
* Compiles the query.
*
* @throws QueryException query exception
*/
public void compile() throws QueryException {
parse();
qc.compile();
}
/**
* Returns a memory-efficient result iterator. In most cases, the query will only be fully
* evaluated if all items of this iterator are requested.
*
* @return result iterator
* @throws QueryException query exception
*/
public Iter iter() throws QueryException {
parse();
return qc.iter();
}
/**
* Evaluates the query and returns the resulting value.
*
* @return result value
* @throws QueryException query exception
*/
public Value value() throws QueryException {
parse();
return qc.iter().value();
}
/**
* This function is called by the GUI; use {@link #iter()} or {@link #value()} instead. Caches and
* returns the result of the specified query. If all nodes are of the same database instance, the
* returned value will be of type {@link DBNodes}.
*
* @param max maximum number of results to cache (negative: return all values)
* @return result of query
* @throws QueryException query exception
*/
public Value cache(final int max) throws QueryException {
parse();
return qc.cache(max);
}
/**
* Binds a value with the specified type to a global variable. If the value is an {@link Expr}
* instance, it is directly assigned. Otherwise, it is first cast to the appropriate XQuery type.
* If {@code "json"} is specified as type, the value is interpreted according to the rules
* specified in {@link JsonMapConverter}.
*
* @param name name of variable
* @param value value to be bound
* @param type type (may be {@code null})
* @return self reference
* @throws QueryException query exception
*/
public QueryProcessor bind(final String name, final Object value, final String type)
throws QueryException {
qc.bind(name, value, type, sc);
return this;
}
/**
* Binds a value to a global variable.
*
* @param name name of variable
* @param value value to be bound
* @return self reference
* @throws QueryException query exception
*/
public QueryProcessor bind(final String name, final Object value) throws QueryException {
return bind(name, value, null);
}
/**
* Binds an XQuery value to a global variable.
*
* @param name name of variable
* @param value value to be bound
* @return self reference
* @throws QueryException query exception
*/
public QueryProcessor bind(final String name, final Value value) throws QueryException {
qc.bind(name, value, sc);
return this;
}
/**
* Binds the context value.
*
* @param value value to be bound
* @return self reference
* @throws QueryException query exception
*/
public QueryProcessor context(final Object value) throws QueryException {
return context(value, null);
}
/**
* Binds the context value.
*
* @param value XQuery value to be bound
* @return self reference
*/
public QueryProcessor context(final Value value) {
qc.context(value, sc);
return this;
}
/**
* Binds the HTTP context to the query processor.
*
* @param value HTTP context
* @return self reference
*/
public QueryProcessor http(final Object value) {
qc.http(value);
return this;
}
/**
* Binds the context value with a specified type, using the same rules as for {@link #bind binding
* variables}.
*
* @param value value to be bound
* @param type type (may be {@code null})
* @return self reference
* @throws QueryException query exception
*/
public QueryProcessor context(final Object value, final String type) throws QueryException {
qc.context(value, type, sc);
return this;
}
/**
* Declares a namespace. A namespace is undeclared if the {@code uri} is an empty string. The
* default element namespaces is set if the {@code prefix} is empty.
*
* @param prefix namespace prefix
* @param uri namespace uri
* @return self reference
* @throws QueryException query exception
*/
public QueryProcessor namespace(final String prefix, final String uri) throws QueryException {
sc.namespace(prefix, uri);
return this;
}
/**
* Assigns a URI resolver.
*
* @param resolver resolver
* @return self reference
*/
public QueryProcessor uriResolver(final UriResolver resolver) {
sc.resolver = resolver;
return this;
}
/**
* Returns a serializer for the given output stream. Optional output declarations within the query
* will be included in the serializer instance.
*
* @param os output stream
* @return serializer instance
* @throws IOException query exception
* @throws QueryException query exception
*/
public Serializer getSerializer(final OutputStream os) throws IOException, QueryException {
compile();
try {
return Serializer.get(os, qc.serParams()).sc(sc);
} catch (final QueryIOException ex) {
throw ex.getCause();
}
}
/**
* Adds a module reference. Only called from the test APIs.
*
* @param uri module uri
* @param file file name
*/
public void module(final String uri, final String file) {
qc.modDeclared.put(uri, file);
}
/**
* Returns the query string.
*
* @return query
*/
public String query() {
return query;
}
@Override
public void close() {
qc.close();
}
@Override
public void databases(final LockResult lr) {
qc.databases(lr);
}
/**
* Returns the number of performed updates after query execution, or {@code 0}.
*
* @return number of updates
*/
public int updates() {
return updating ? qc.updates().size() : 0;
}
/**
* Returns query information.
*
* @return query information
*/
public String info() {
return qc.info();
}
/**
* Checks if the specified XQuery string is a library module.
*
* @param qu query string
* @return result of check
*/
public static boolean isLibrary(final String qu) {
return LIBMOD_PATTERN.matcher(removeComments(qu, 80)).matches();
}
/**
* Removes comments from the specified string and returns the first characters of a query.
*
* @param qu query string
* @param max maximum length of string to return
* @return result
*/
public static String removeComments(final String qu, final int max) {
final StringBuilder sb = new StringBuilder();
int m = 0;
boolean s = false;
final int cl = qu.length();
for (int c = 0; c < cl && sb.length() < max; ++c) {
final char ch = qu.charAt(c);
if (ch == 0x0d) continue;
if (ch == '(' && c + 1 < cl && qu.charAt(c + 1) == ':') {
if (m == 0 && !s) {
sb.append(' ');
s = true;
}
++m;
++c;
} else if (m != 0 && ch == ':' && c + 1 < cl && qu.charAt(c + 1) == ')') {
--m;
++c;
} else if (m == 0) {
if (ch > ' ') sb.append(ch);
else if (!s) sb.append(' ');
s = ch <= ' ';
}
}
if (sb.length() >= max) sb.append("...");
return sb.toString().trim();
}
/**
* Returns a tree representation of the query plan.
*
* @return root node
*/
public FDoc plan() {
return new FDoc().add(qc.plan());
}
@Override
public String shortInfo() {
return PLEASE_WAIT_D;
}
@Override
public String detailedInfo() {
return PLEASE_WAIT_D;
}
@Override
public String toString() {
return query;
}
}
/**
* This class represents a single RESTXQ function.
*
* @author BaseX Team 2005-12, BSD License
* @author Christian Gruen
*/
final class RestXqFunction implements Comparable<RestXqFunction> {
/** Pattern for a single template. */
private static final Pattern TEMPLATE = Pattern.compile("\\s*\\{\\s*\\$(.+?)\\s*\\}\\s*");
/** Supported methods. */
EnumSet<HTTPMethod> methods = EnumSet.allOf(HTTPMethod.class);
/** Serialization parameters. */
final SerializerProp output = new SerializerProp();
/** Associated function. */
final StaticUserFunc function;
/** Associated module. */
final RestXqModule module;
/** Path. */
RestXqPath path;
/** Query parameters. */
final ArrayList<RestXqParam> queryParams = new ArrayList<RestXqParam>();
/** Form parameters. */
final ArrayList<RestXqParam> formParams = new ArrayList<RestXqParam>();
/** Header parameters. */
final ArrayList<RestXqParam> headerParams = new ArrayList<RestXqParam>();
/** Cookie parameters. */
final ArrayList<RestXqParam> cookieParams = new ArrayList<RestXqParam>();
/** Query context. */
private final QueryContext context;
/** Consumed media types. */
private final StringList consumes = new StringList();
/** Returned media types. */
private final StringList produces = new StringList();
/** Post/Put variable. */
private QNm requestBody;
/**
* Constructor.
*
* @param uf associated user function
* @param qc query context
* @param m associated module
*/
RestXqFunction(final StaticUserFunc uf, final QueryContext qc, final RestXqModule m) {
function = uf;
context = qc;
module = m;
}
/**
* Processes the HTTP request. Parses new modules and discards obsolete ones.
*
* @param http HTTP context
* @throws Exception exception
*/
void process(final HTTPContext http) throws Exception {
try {
module.process(http, this);
} catch (final QueryException ex) {
if (ex.file() == null) ex.info(function.info);
throw ex;
}
}
/**
* 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;
}
/**
* Checks if an HTTP request matches this function and its constraints.
*
* @param http http context
* @return result of check
*/
boolean matches(final HTTPContext http) {
// check method, path, consumed and produced media type
return methods.contains(http.method) && pathMatches(http) && consumes(http) && produces(http);
}
/**
* Binds the annotated variables.
*
* @param http http context
* @param arg argument array
* @throws QueryException query exception
* @throws IOException I/O exception
*/
void bind(final HTTPContext http, final Expr[] arg) throws QueryException, IOException {
// bind variables from segments
for (int s = 0; s < path.size; s++) {
final Matcher m = TEMPLATE.matcher(path.segment[s]);
if (!m.find()) continue;
final QNm qnm = new QNm(token(m.group(1)), context);
bind(qnm, arg, new Atm(http.segment(s)));
}
// cache request body
final String ct = http.contentType();
IOContent body = null;
if (requestBody != null) {
body = cache(http, null);
try {
// bind request body in the correct format
body.name(http.method + IO.XMLSUFFIX);
bind(requestBody, arg, Parser.item(body, context.context.prop, ct));
} catch (final IOException ex) {
error(INPUT_CONV, ex);
}
}
// bind query parameters
final Map<String, String[]> params = http.params();
for (final RestXqParam rxp : queryParams) bind(rxp, arg, params.get(rxp.key));
// bind form parameters
if (!formParams.isEmpty()) {
if (MimeTypes.APP_FORM.equals(ct)) {
// convert parameters encoded in a form
body = cache(http, body);
addParams(body.toString(), params);
}
for (final RestXqParam rxp : formParams) bind(rxp, arg, params.get(rxp.key));
}
// bind header parameters
for (final RestXqParam rxp : headerParams) {
final StringList sl = new StringList();
final Enumeration<?> en = http.req.getHeaders(rxp.key);
while (en.hasMoreElements()) {
for (final String s : en.nextElement().toString().split(", *")) sl.add(s);
}
bind(rxp, arg, sl.toArray());
}
// bind cookie parameters
final Cookie[] ck = http.req.getCookies();
for (final RestXqParam rxp : cookieParams) {
String v = null;
if (ck != null) {
for (final Cookie c : ck) {
if (rxp.key.equals(c.getName())) v = c.getValue();
}
}
if (v == null) bind(rxp, arg);
else bind(rxp, arg, v);
}
}
/**
* Creates an exception with the specified message.
*
* @param msg message
* @param ext error extension
* @return exception
* @throws QueryException query exception
*/
QueryException error(final String msg, final Object... ext) throws QueryException {
throw new QueryException(function.info, Err.BASX_RESTXQ, Util.info(msg, ext));
}
@Override
public int compareTo(final RestXqFunction rxf) {
return path.compareTo(rxf.path);
}
// PRIVATE METHODS ====================================================================
/**
* Checks the specified template and adds a variable.
*
* @param tmp template string
* @param declared variable declaration flags
* @return resulting variable
* @throws QueryException query exception
*/
private QNm checkVariable(final String tmp, final boolean[] declared) throws QueryException {
return checkVariable(tmp, AtomType.ITEM, declared);
}
/**
* Checks the specified template and adds a variable.
*
* @param tmp template string
* @param type allowed type
* @param declared variable declaration flags
* @return resulting variable
* @throws QueryException query exception
*/
private QNm checkVariable(final String tmp, final Type type, final boolean[] declared)
throws QueryException {
final Var[] args = function.args;
final Matcher m = TEMPLATE.matcher(tmp);
if (!m.find()) error(INV_TEMPLATE, tmp);
final byte[] vn = token(m.group(1));
if (!XMLToken.isQName(vn)) error(INV_VARNAME, vn);
final QNm qnm = new QNm(vn, context);
int r = -1;
while (++r < args.length && !args[r].name.eq(qnm)) ;
if (r == args.length) error(UNKNOWN_VAR, vn);
if (declared[r]) error(VAR_ASSIGNED, vn);
final SeqType st = args[r].declaredType();
if (args[r].checksType() && !st.type.instanceOf(type)) error(INV_VARTYPE, vn, type);
declared[r] = true;
return qnm;
}
/**
* Checks if the path matches the HTTP request.
*
* @param http http context
* @return result of check
*/
private boolean pathMatches(final HTTPContext http) {
return path.matches(http);
}
/**
* Checks if the consumed content type matches.
*
* @param http http context
* @return result of check
*/
private boolean consumes(final HTTPContext http) {
// return true if no type is given
if (consumes.isEmpty()) return true;
// return true if no content type is specified by the user
final String ct = http.contentType();
if (ct == null) return true;
// check if any combination matches
for (final String c : consumes) {
if (MimeTypes.matches(c, ct)) return true;
}
return false;
}
/**
* Checks if the produced content type matches.
*
* @param http http context
* @return result of check
*/
private boolean produces(final HTTPContext http) {
// return true if no type is given
if (produces.isEmpty()) return true;
// check if any combination matches
for (final String pr : http.produces()) {
for (final String p : produces) {
if (MimeTypes.matches(p, pr)) return true;
}
}
return false;
}
/**
* Binds the specified parameter to a variable.
*
* @param rxp parameter
* @param args argument array
* @param values values to be bound; the parameter's default value is assigned if the argument is
* {@code null} or empty
* @throws QueryException query exception
*/
private void bind(final RestXqParam rxp, final Expr[] args, final String... values)
throws QueryException {
final Value val;
if (values == null || values.length == 0) {
val = rxp.value;
} else {
final ValueBuilder vb = new ValueBuilder();
for (final String s : values) vb.add(new Atm(s));
val = vb.value();
}
bind(rxp.name, args, val);
}
/**
* Binds the specified value to a variable.
*
* @param name variable name
* @param args argument array
* @param value value to be bound
* @throws QueryException query exception
*/
private void bind(final QNm name, final Expr[] args, final Value value) throws QueryException {
// skip nulled values
if (value == null) return;
for (int i = 0; i < function.args.length; i++) {
final Var var = function.args[i];
if (!var.name.eq(name)) continue;
// casts and binds the value
args[i] = var.checkType(value, context, null);
break;
}
}
/**
* Returns the specified value as an atomic string.
*
* @param value value
* @param name name
* @return string
* @throws QueryException HTTP exception
*/
private String toString(final Value value, final QNm name) throws QueryException {
if (!(value instanceof Str)) error(ANN_STRING, "%", name.string(), value);
return ((Str) value).toJava();
}
/**
* 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));
}
/**
* 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());
}
// PRIVATE STATIC METHODS =============================================================
/**
* Caches the request body, if not done yet.
*
* @param http http context
* @param cache cache existing cache reference
* @return cache
* @throws IOException I/O exception
*/
private static IOContent cache(final HTTPContext http, final IOContent cache) throws IOException {
if (cache != null) return cache;
final BufferInput bi = new BufferInput(http.req.getInputStream());
final IOContent io = new IOContent(bi.content());
io.name(http.method + IO.XMLSUFFIX);
return io;
}
/**
* Adds parameters from the passed on request body.
*
* @param body request body
* @param params map parameters
*/
private static void addParams(final String body, final Map<String, String[]> params) {
for (final String nv : body.split("&")) {
final String[] parts = nv.split("=", 2);
if (parts.length < 2) continue;
try {
params.put(parts[0], new String[] {URLDecoder.decode(parts[1], Token.UTF8)});
} catch (final Exception ex) {
Util.notexpected(ex);
}
}
}
}