2 * Copyright (c) 2019 Pantheon Technologies, s.r.o. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
8 package org.opendaylight.yangtools.yang.xpath.impl;
10 import static java.util.Objects.requireNonNull;
11 import static org.opendaylight.yangtools.yang.xpath.impl.ParseTreeUtils.getChild;
12 import static org.opendaylight.yangtools.yang.xpath.impl.ParseTreeUtils.illegalShape;
13 import static org.opendaylight.yangtools.yang.xpath.impl.ParseTreeUtils.verifyTerminal;
14 import static org.opendaylight.yangtools.yang.xpath.impl.ParseTreeUtils.verifyToken;
16 import com.google.common.base.VerifyException;
17 import com.google.common.collect.ImmutableSet;
18 import java.util.ArrayList;
19 import java.util.Collection;
20 import javax.xml.xpath.XPathExpressionException;
21 import org.antlr.v4.runtime.CharStreams;
22 import org.antlr.v4.runtime.CommonTokenStream;
23 import org.opendaylight.yangtools.yang.common.UnresolvedQName;
24 import org.opendaylight.yangtools.yang.common.YangNamespaceContext;
25 import org.opendaylight.yangtools.yang.xpath.antlr.instanceIdentifierLexer;
26 import org.opendaylight.yangtools.yang.xpath.antlr.instanceIdentifierParser;
27 import org.opendaylight.yangtools.yang.xpath.antlr.instanceIdentifierParser.EqQuotedStringContext;
28 import org.opendaylight.yangtools.yang.xpath.antlr.instanceIdentifierParser.KeyPredicateContext;
29 import org.opendaylight.yangtools.yang.xpath.antlr.instanceIdentifierParser.KeyPredicateExprContext;
30 import org.opendaylight.yangtools.yang.xpath.antlr.instanceIdentifierParser.LeafListPredicateContext;
31 import org.opendaylight.yangtools.yang.xpath.antlr.instanceIdentifierParser.LeafListPredicateExprContext;
32 import org.opendaylight.yangtools.yang.xpath.antlr.instanceIdentifierParser.NodeIdentifierContext;
33 import org.opendaylight.yangtools.yang.xpath.antlr.instanceIdentifierParser.PathArgumentContext;
34 import org.opendaylight.yangtools.yang.xpath.antlr.instanceIdentifierParser.PosContext;
35 import org.opendaylight.yangtools.yang.xpath.antlr.instanceIdentifierParser.PredicateContext;
36 import org.opendaylight.yangtools.yang.xpath.antlr.instanceIdentifierParser.QuotedStringContext;
37 import org.opendaylight.yangtools.yang.xpath.api.YangBinaryOperator;
38 import org.opendaylight.yangtools.yang.xpath.api.YangExpr;
39 import org.opendaylight.yangtools.yang.xpath.api.YangLiteralExpr;
40 import org.opendaylight.yangtools.yang.xpath.api.YangLocationPath;
41 import org.opendaylight.yangtools.yang.xpath.api.YangLocationPath.Absolute;
42 import org.opendaylight.yangtools.yang.xpath.api.YangLocationPath.QNameStep;
43 import org.opendaylight.yangtools.yang.xpath.api.YangLocationPath.Step;
44 import org.opendaylight.yangtools.yang.xpath.api.YangQNameExpr;
45 import org.opendaylight.yangtools.yang.xpath.api.YangXPathAxis;
46 import org.opendaylight.yangtools.yang.xpath.api.YangXPathMathMode;
47 import org.opendaylight.yangtools.yang.xpath.api.YangXPathMathSupport;
49 abstract class InstanceIdentifierParser {
50 static final class Base extends InstanceIdentifierParser {
51 Base(final YangXPathMathMode mathMode) {
56 YangQNameExpr createExpr(final String prefix, final String localName) {
57 return YangQNameExpr.of(UnresolvedQName.Qualified.of(prefix, localName));
61 QNameStep createChildStep(final String prefix, final String localName, final Collection<YangExpr> predicates) {
62 return YangXPathAxis.CHILD.asStep(UnresolvedQName.Qualified.of(prefix, localName), predicates);
66 static final class Qualified extends InstanceIdentifierParser {
67 final YangNamespaceContext namespaceContext;
69 Qualified(final YangXPathMathMode mathMode, final YangNamespaceContext namespaceContext) {
71 this.namespaceContext = requireNonNull(namespaceContext);
75 QNameStep createChildStep(final String prefix, final String localName, final Collection<YangExpr> predicates) {
76 return YangXPathAxis.CHILD.asStep(namespaceContext.createQName(prefix, localName), predicates);
81 YangQNameExpr createExpr(final String prefix, final String localName) {
82 return YangQNameExpr.of(namespaceContext.createQName(prefix, localName));
87 private final YangXPathMathSupport mathSupport;
89 InstanceIdentifierParser(final YangXPathMathMode mathMode) {
90 mathSupport = mathMode.getSupport();
93 final Absolute interpretAsInstanceIdentifier(final YangLiteralExpr expr) throws XPathExpressionException {
94 final var lexer = new instanceIdentifierLexer(CharStreams.fromString(expr.getLiteral()));
95 final var parser = new instanceIdentifierParser(new CommonTokenStream(lexer));
96 final var listener = new CapturingErrorListener();
97 lexer.removeErrorListeners();
98 lexer.addErrorListener(listener);
99 parser.removeErrorListeners();
100 parser.addErrorListener(listener);
102 final var id = parser.instanceIdentifier();
103 listener.reportError();
105 final int length = id.getChildCount();
106 final var steps = new ArrayList<Step>(length / 2);
107 for (int i = 1; i < length; i += 2) {
108 steps.add(parsePathArgument(getChild(id, PathArgumentContext.class, i)));
111 return YangLocationPath.absolute(steps);
114 abstract YangQNameExpr createExpr(String prefix, String localName);
116 abstract QNameStep createChildStep(String prefix, String localName, Collection<YangExpr> predicates);
118 private QNameStep parsePathArgument(final PathArgumentContext expr) {
119 final NodeIdentifierContext childExpr = getChild(expr, NodeIdentifierContext.class, 0);
120 final String prefix = verifyIdentifier(childExpr, 0);
121 final String localName = verifyIdentifier(childExpr, 2);
123 return switch (expr.getChildCount()) {
124 case 1 -> createChildStep(prefix, localName, ImmutableSet.of());
125 case 2 -> createChildStep(prefix, localName, parsePredicate(getChild(expr, PredicateContext.class, 1)));
126 default -> throw illegalShape(expr);
130 private Collection<YangExpr> parsePredicate(final PredicateContext expr) {
131 final var first = expr.getChild(0);
132 if (first instanceof LeafListPredicateContext llp) {
133 return ImmutableSet.of(YangBinaryOperator.EQUALS.exprWith(YangLocationPath.self(),
134 parseEqStringValue(getChild(llp.getChild(LeafListPredicateExprContext.class, 0),
135 EqQuotedStringContext.class, 1))));
136 } else if (first instanceof PosContext pc) {
137 return ImmutableSet.of(YangBinaryOperator.EQUALS.exprWith(FunctionSupport.POSITION,
138 mathSupport.createNumber(pc.getToken(instanceIdentifierParser.PositiveIntegerValue, 0).getText())));
141 final int length = expr.getChildCount();
142 final var ret = new ArrayList<YangExpr>(length);
143 for (int i = 0; i < length; ++i) {
144 final var pred = getChild(expr, KeyPredicateContext.class, i).getChild(KeyPredicateExprContext.class, 0);
145 ret.add(YangBinaryOperator.EQUALS.exprWith(
146 createChildExpr(getChild(pred, NodeIdentifierContext.class, 0)),
147 parseEqStringValue(getChild(pred, EqQuotedStringContext.class, 1))));
153 private YangQNameExpr createChildExpr(final NodeIdentifierContext expr) {
154 return createExpr(verifyIdentifier(expr, 0), verifyIdentifier(expr, 2));
157 private static String verifyIdentifier(final NodeIdentifierContext expr, final int child) {
158 return verifyToken(expr, child, instanceIdentifierParser.Identifier).getText();
161 private static YangLiteralExpr parseEqStringValue(final EqQuotedStringContext expr) {
162 final var quotedString = getChild(expr, QuotedStringContext.class, expr.getChildCount() - 1);
163 return switch (quotedString.getChildCount()) {
164 case 1 -> YangLiteralExpr.empty();
166 final var terminal = verifyTerminal(quotedString.getChild(0));
167 final var token = terminal.getSymbol();
168 final var literal = switch (token.getType()) {
169 case instanceIdentifierParser.DQUOT_STRING -> unescape(token.getText());
170 case instanceIdentifierParser.SQUOT_STRING -> token.getText();
171 default -> throw illegalShape(terminal);
173 yield YangLiteralExpr.of(literal);
175 default -> throw illegalShape(quotedString);
179 private static String unescape(final String escaped) {
180 final int firstEscape = escaped.indexOf('\\');
181 return firstEscape == -1 ? escaped : unescape(escaped, firstEscape);
184 private static String unescape(final String escaped, final int firstEscape) {
185 // Sizing: optimize allocation for only a single escape
186 final int length = escaped.length();
187 final var sb = new StringBuilder(length - 1).append(escaped, 0, firstEscape);
189 int esc = firstEscape;
191 final var ch = escaped.charAt(esc + 1);
198 default -> throw new VerifyException("Unexpected escaped char '" + ch + "'");
201 final int start = esc + 2;
202 esc = escaped.indexOf('\\', start);
204 return sb.append(escaped, start, length).toString();
207 sb.append(escaped, start, esc);