diff options
Diffstat (limited to 'debian/htdig/htdig-3.2.0b6/htfuzzy/Prefix.cc')
| -rw-r--r-- | debian/htdig/htdig-3.2.0b6/htfuzzy/Prefix.cc | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/debian/htdig/htdig-3.2.0b6/htfuzzy/Prefix.cc b/debian/htdig/htdig-3.2.0b6/htfuzzy/Prefix.cc new file mode 100644 index 00000000..1e254d80 --- /dev/null +++ b/debian/htdig/htdig-3.2.0b6/htfuzzy/Prefix.cc @@ -0,0 +1,150 @@ +// +// Prefix.cc +// +// Prefix: The prefix fuzzy algorithm. Performs a O(log n) search on for words +// matching the *prefix* specified--thus significantly faster than a full +// substring search. +// +// Part of the ht://Dig package <http://www.htdig.org/> +// Copyright (c) 1995-2004 The ht://Dig Group +// For copyright details, see the file COPYING in your distribution +// or the GNU Library General Public License (LGPL) version 2 or later +// <http://www.gnu.org/copyleft/lgpl.html> +// +// $Id: Prefix.cc,v 1.17 2004/05/28 13:15:20 lha Exp $ +// + +#ifdef HAVE_CONFIG_H +#include "htconfig.h" +#endif /* HAVE_CONFIG_H */ + +#include <fcntl.h> + +#include "Prefix.h" +#include "htString.h" +#include "List.h" +#include "StringMatch.h" +#include "HtConfiguration.h" + + +//***************************************************************************** +// Prefix::Prefix(const HtConfiguration& config_arg) +// +Prefix::Prefix(const HtConfiguration& config_arg) : + Fuzzy(config_arg) +{ + name = "prefix"; +} + + +//***************************************************************************** +// Prefix::~Prefix() +// +Prefix::~Prefix() +{ +} + + +//***************************************************************************** +// +// Prefix search +// +void +Prefix::getWords(char *w, List &words) +{ + if (w == NULL || w[0] == '\0') + return; + + String stripped = w; + HtStripPunctuation(stripped); + w = stripped.get(); + + const String prefix_suffix = config["prefix_match_character"]; + int prefix_suffix_length = prefix_suffix.length(); + int minimum_prefix_length = config.Value("minimum_prefix_length"); + + if (debug) + cerr << " word=" << w << " prefix_suffix=" << prefix_suffix + << " prefix_suffix_length=" << prefix_suffix_length + << " minimum_prefix_length=" << minimum_prefix_length << "\n"; + + if ((int)strlen(w) < minimum_prefix_length + prefix_suffix_length) + return; + + // A null prefix character means that prefix matching should be + // applied to every search word; otherwise return if the word does + // not end in the prefix character(s). + // + if (prefix_suffix_length > 0 + && strcmp(prefix_suffix, w+strlen(w)-prefix_suffix_length)) + return; + + HtWordList wordDB(config); + if (wordDB.Open(config["word_db"], O_RDONLY) == NOTOK) + return; + + int wordCount = 0; + int maximumWords = config.Value("max_prefix_matches", 1000); + String s; + int len = strlen(w) - prefix_suffix_length; + + // Strip the prefix character(s) + char w2[8192]; + strncpy(w2, w, sizeof(w2) - 1); + w2[sizeof(w2) - 1] = '\0'; + w2[strlen(w2) - prefix_suffix_length] = '\0'; + String w3(w2); + w3.lowercase(); + List *wordList = wordDB.Prefix(w3.get()); + WordReference *word_ref; + String last_word; + + wordList->Start_Get(); + while (wordCount < maximumWords && (word_ref = (WordReference *) wordList->Get_Next() )) + { + s = word_ref->Key().GetWord(); + + // If we're somehow past the original word, we're done + if (mystrncasecmp(s.get(), w, len)) + break; + + // If this is a duplicate word, ignore it + if (last_word.length() != 0 && last_word == s) + continue; + + last_word = s; + words.Add(new String(s)); + wordCount++; + } + if (wordList) { + wordList->Destroy(); + delete wordList; + } + wordDB.Close(); +} + + +//***************************************************************************** +int +Prefix::openIndex() +{ + return 0; +} + + +//***************************************************************************** +void +Prefix::generateKey(char *, String &) +{ +} + + +//***************************************************************************** +void +Prefix::addWord(char *) +{ +} + + + + |