move AhoCorasick to AhoCorasick.js

2026-08-13 06:18:53 +00:00 · 2025-06-09 22:45:06 +08:00
parent f3b673ad3a
commit 01c2ef7a96
1 changed files with 152 additions and 0 deletions
@@ -0,0 +1,152 @@
+/*\
+title: $:/core/modules/utils/aho-corasick.js
+type: application/javascript
+module-type: utils
+
+Aho-Corasick string matching algorithm implementation with enhanced error handling
+for TiddlyWiki freelinking functionality.
+
+\*/
+(function(){
+
+"use strict";
+
+/**
+ * Aho-Corasick implementation with enhanced error handling
+ * @constructor
+ */
+function AhoCorasick() {
+	this.trie = {};
+	this.failure = {};
+	this.output = {};
+}
+
+/**
+ * Add a pattern to the Aho-Corasick automaton
+ * @param {string} pattern - The pattern to add
+ * @param {number} index - The index of the pattern for identification
+ */
+AhoCorasick.prototype.addPattern = function(pattern, index) {
+	if(!pattern || typeof pattern !== "string") {
+		return;
+	}
+	var node = this.trie;
+	for(var i = 0; i < pattern.length; i++) {
+		var char = pattern[i];
+		if(!node[char]) {
+			node[char] = {};
+		}
+		node = node[char];
+	}
+	if(!node.$) {
+		node.$ = [];
+	}
+	node.$.push({ pattern: pattern, index: index });
+};
+
+/**
+ * Build failure links for the Aho-Corasick automaton
+ */
+AhoCorasick.prototype.buildFailureLinks = function() {
+	var queue = [];
+	var root = this.trie;
+	this.failure[root] = root;
+	
+	// Initialize first level failure links
+	for(var char in root) {
+		if(root[char] && char !== '$') {
+			this.failure[root[char]] = root;
+			queue.push(root[char]);
+		}
+	}
+	
+	var maxIterations = 100000; // Prevent infinite loops
+	var iteration = 0;
+	
+	while(queue.length && iteration < maxIterations) {
+		var node = queue.shift();
+		for(var char in node) {
+			if(node[char] && char !== '$') {
+				var child = node[char];
+				var fail = this.failure[node];
+				var failCount = 0;
+				var maxFailCount = 1000; // Prevent deep failure chains
+				
+				while(fail && !fail[char] && failCount < maxFailCount) {
+					fail = this.failure[fail];
+					failCount++;
+				}
+				
+				this.failure[child] = fail[char] || this.trie;
+				
+				// Copy output from failure link
+				if(this.failure[child].$) {
+					if(!child.$) {
+						child.$ = [];
+					}
+					child.$.push.apply(child.$, this.failure[child].$);
+				}
+				
+				queue.push(child);
+			}
+		}
+		iteration++;
+	}
+	
+	if(iteration >= maxIterations) {
+		throw new Error("Aho-Corasick: buildFailureLinks exceeded max iterations");
+	}
+};
+
+/**
+ * Search for all patterns in the given text
+ * @param {string} text - The text to search in
+ * @returns {Array} Array of match objects with pattern, index, length, and titleIndex properties
+ */
+AhoCorasick.prototype.search = function(text) {
+	if(!text || typeof text !== "string") {
+		return [];
+	}
+	
+	var matches = [];
+	var node = this.trie;
+	var maxIterations = text.length * 10; // Prevent infinite loops
+	var iteration = 0;
+	
+	for(var i = 0; i < text.length && iteration < maxIterations; i++) {
+		var char = text[i];
+		var transitionCount = 0;
+		var maxTransitionCount = 1000; // Prevent deep transitions
+		
+		while(node && !node[char] && transitionCount < maxTransitionCount) {
+			node = this.failure[node];
+			transitionCount++;
+		}
+		
+		node = node[char] || this.trie;
+		
+		if(node.$) {
+			for(var j = 0; j < node.$.length; j++) {
+				var match = node.$[j];
+				matches.push({
+					pattern: match.pattern,
+					index: i - match.pattern.length + 1,
+					length: match.pattern.length,
+					titleIndex: match.index
+				});
+			}
+		}
+		iteration++;
+	}
+	
+	if(iteration >= maxIterations) {
+		throw new Error("Aho-Corasick: search exceeded max iterations");
+	}
+	
+	return matches;
+};
+
+// Export the AhoCorasick constructor
+exports.AhoCorasick = AhoCorasick;
+
+})();