00001 // 00002 // Part of the ht://Dig package <http://www.htdig.org/> 00003 // Copyright (c) 1999, 2000, 2001 The ht://Dig Group 00004 // For copyright details, see the file COPYING in your distribution 00005 // or the GNU General Public License version 2 or later 00006 // <http://www.gnu.org/copyleft/gpl.html> 00007 // 00008 // $Id: WordSearch_8h-source.html,v 1.1 2008年06月08日 10:13:23 sebdiaz Exp $ 00009 // 00010 // ************************* WordSearch implementation ******************** 00011 // 00012 // NAME 00013 // 00014 // Solve a query from a WordTree syntax tree 00015 // 00016 // SYNOPSIS 00017 // 00018 // #include <WordSearch.h> 00019 // 00020 // WordTree* expr = get_query(); 00021 // WordSearch search; 00022 // search.limit_count = NUMBER_OF_RESULTS; 00023 // WordMatch* search.Search(expr); 00024 // ... 00025 // 00026 // DESCRIPTION 00027 // 00028 // The WordSearch class is a wrapper to query an inverted index 00029 // using a WordTree syntax tree. 00030 // 00031 // END 00032 // 00033 00034 #ifndef _WordSearch_h 00035 #define _WordSearch_h 00036 00037 #include <WordList.h> 00038 #include <WordMatch.h> 00039 #include <WordTree.h> 00040 00041 class WordSearch { 00042 public: 00043 WordSearch(WordList* words); 00044 00045 ~WordSearch() { 00046 if(expr) delete expr; 00047 } 00048 00049 //- 00050 // Set the list of documents that must be ignored. 00051 // 00052 inline int SetResults(WordResults* nresults) { results = nresults; return OK; } 00053 //- 00054 // Get the list of documents that must be ignored. 00055 // 00056 inline WordResults* GetResults() { return results; } 00057 00058 //- 00059 // Save the context of the last document retrieved in the context_out 00060 // data member. 00061 // 00062 int ContextSave(int status); 00063 //- 00064 // Restore a search context from the context_in data member. 00065 // 00066 int ContextRestore(); 00067 00068 //- 00069 // First call SearchFromCache and then SearchFromIndex if SearchFromCache 00070 // returned 0. 00071 // 00072 WordMatches *Search(); 00073 //- 00074 // Attempt to retrieve the results from the cache. Returns 0 if 00075 // the search cannot be resolved from the cache. Returns the list 00076 // of matches if the search can be resolved from the cache. If the 00077 // cache only contains part of the desired results, call SearchFromIndex 00078 // to get the others. If the cache does not contain any of the desired 00079 // results, return 0. 00080 // 00081 int SearchFromCache(); 00082 //- 00083 // Perform a search from the <b>expr</b> specifications. 00084 // Restore the context from <i>context_in</i> on <b>expr</b>. 00085 // Then skip (using WalkNext) <i>limit_bottom</i> entries. 00086 // Then collect in a WordMatch array of size <i>limit_count</i> 00087 // each match returned by WalkNext. When finished store 00088 // the context (ContextSave) in <i>context_out</i>. 00089 // It is the responsibility of the caller to free the WordMatch 00090 // array. If no match are found a null pointer is returned. 00091 // 00092 int SearchFromIndex(unsigned int length); 00093 00094 //- 00095 // Search backend, only run the WalkNext loop but does not 00096 // allocate/deallocate data. If limit_bottom is above all matches 00097 // return the last valid limit_count range and reset limit_bottom 00098 // accordingly. 00099 // 00100 int SearchLoop(WordTree *expr, unsigned int length); 00101 00102 inline int Verbose(int verbosity) { return verbose = verbosity; } 00103 00104 // 00105 // Internal 00106 // 00107 WordList* words; 00108 //- 00109 // A list of documents that must be ignored 00110 // 00111 WordResults *results; 00112 int verbose; 00113 00114 // 00115 // Input/Output 00116 // 00117 // 00118 // Input: Absolute position of the document pointed by context_in. The 00119 // limit_bottom position is relative to limit_base. 00120 // Output: Absolute position of the first document returned. 00121 // 00122 unsigned int limit_base; 00123 00124 // 00125 // Input 00126 // 00127 // 00128 // Maximum number of matches returned 00129 // 00130 unsigned int limit_count; 00131 // 00132 // Query tree 00133 // 00134 WordTree* expr; 00135 00136 // 00137 // Output 00138 // 00139 // 00140 // Array of at most limit_count matches. The number of valid elements in 00141 // the array is matches_length; 00142 // 00143 WordMatches* matches; 00144 // 00145 // Estimated number of matches. 00146 // 00147 unsigned int matches_total; 00148 }; 00149 00150 #endif /* _WordSearch_h */