package client.net.sf.saxon.ce.trans;
import client.net.sf.saxon.ce.expr.instruct.Template;
import client.net.sf.saxon.ce.pattern.*;
import client.net.sf.saxon.ce.style.StylesheetModule;
import client.net.sf.saxon.ce.type.Type;
import java.util.HashMap;
/**
* The set of rules used to decide strip-space/preserve-space matching of element names in XSLT.
*
* @author Michael H. Kay
*/
public class StripSpaceRules {
// This is a cut-down version of the Mode class, which until 9.3 was used for the job, even though
// it is over-engineered for the task.
private Rule anyElementRule = null;
private Rule unnamedElementRuleChain = null;
private HashMap<Integer, Rule> namedElementRules = new HashMap<Integer, Rule>(32);
private int sequence = 0;
/**
* Default constructor - creates a StripSpaceRules containing no rules
*/
public StripSpaceRules() {
}
/**
* Add a rule
*
* @param test a NodeTest (*, *:local, prefix:*, or QName)
* @param action StripRuleTarget.STRIP or StripRuleTarget.PRESERVE
* @param module the stylesheet module containing the rule
*/
public void addRule(NodeTest test, Template action,
StylesheetModule module, int lineNumber) {
// for fast lookup, we maintain one list for each element name for patterns that can only
// match elements of a given name, one list for each node type for patterns that can only
// match one kind of non-element node, and one generic list.
// Each list is sorted in precedence/priority order so we find the highest-priority rule first
int precedence = module.getPrecedence();
int minImportPrecedence = module.getMinImportPrecedence();
double priority = test.getDefaultPriority();
Pattern pattern = new NodeTestPattern(test);
pattern.setSystemId(module.getSourceElement().getSystemId());
Rule newRule = new Rule(pattern, action, precedence, minImportPrecedence, priority, sequence++, false, null);
newRule.setRank((precedence << 16) + sequence);
if (test instanceof NodeKindTest) {
newRule.setAlwaysMatches(true);
anyElementRule = addRuleToList(newRule, anyElementRule, true);
} else if (test instanceof NameTest) {
newRule.setAlwaysMatches(true);
int fp = test.getFingerprint();
Rule chain = namedElementRules.get(fp);
namedElementRules.put(fp, addRuleToList(newRule, chain, true));
} else {
unnamedElementRuleChain = addRuleToList(newRule, unnamedElementRuleChain, false);
}
}
/**
* Insert a new rule into this list before others of the same precedence
* (we rely on the fact that all rules in a list have the same priority)
* @param newRule the new rule to be added into the list
* @param list the Rule at the head of the list, or null if the list is empty
* @param dropRemainder if only one rule needs to be retained
* @return the new head of the list (which might be the old head, or the new rule if it
* was inserted at the start)
*/
private Rule addRuleToList(Rule newRule, Rule list, boolean dropRemainder) {
if (list == null) {
return newRule;
}
int precedence = newRule.getPrecedence();
Rule rule = list;
Rule prev = null;
while (rule != null) {
if (rule.getPrecedence() <= precedence) {
newRule.setNext(dropRemainder ? null : rule);
if (prev == null) {
return newRule;
} else {
prev.setNext(newRule);
}
break;
} else {
prev = rule;
rule = rule.getNext();
}
}
if (rule == null) {
prev.setNext(newRule);
newRule.setNext(null);
}
return list;
}
/**
* Get the rule corresponding to a given element node, by finding the best pattern match.
*
* @param fingerprint the name of the element node to be matched
* @return the best matching rule, if any (otherwise null).
*/
public Rule getRule(int fingerprint) {
// search the specific list for this node type / node name
Rule bestRule = namedElementRules.get(fingerprint);
// search the list for *:local and prefix:* node tests
if (unnamedElementRuleChain != null) {
bestRule = searchRuleChain(fingerprint, bestRule, unnamedElementRuleChain);
}
// See if there is a "*" rule matching all elements
if (anyElementRule != null) {
bestRule = searchRuleChain(fingerprint, bestRule, anyElementRule);
}
return bestRule;
}
/**
* Search a chain of rules
* @param fingerprint the name of the element node being matched
* @param bestRule the best rule so far in terms of precedence and priority (may be null)
* @param head the rule at the head of the chain to be searched
* @return the best match rule found in the chain, or the previous best rule, or null
* @throws client.net.sf.saxon.ce.trans.XPathException
*/
private Rule searchRuleChain(int fingerprint, Rule bestRule, Rule head) {
while (head != null) {
if (bestRule != null) {
int rank = head.compareRank(bestRule);
if (rank < 0) {
// if we already have a match, and the precedence or priority of this
// rule is lower, quit the search
break;
} else if (rank == 0) {
// this rule has the same precedence and priority as the matching rule already found
if (head.isAlwaysMatches() ||
head.getPattern().getNodeTest().matches(Type.ELEMENT, fingerprint, -1)) {
// reportAmbiguity(bestRule, head);
// We no longer report the recoverable error XTRE0270, we always
// take the recovery action.
// choose whichever one comes last (assuming the error wasn't fatal)
bestRule = head;
break;
} else {
// keep searching other rules of the same precedence and priority
}
} else {
// this rule has higher rank than the matching rule already found
if (head.isAlwaysMatches() ||
head.getPattern().getNodeTest().matches(Type.ELEMENT, fingerprint, -1)) {
bestRule = head;
}
}
} else if (head.isAlwaysMatches() ||
head.getPattern().getNodeTest().matches(Type.ELEMENT, fingerprint, -1)) {
bestRule = head;
break;
}
head = head.getNext();
}
return bestRule;
}
}
// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// This Source Code Form is “Incompatible With Secondary Licenses”, as defined by the Mozilla Public License, v. 2.0.