http://www.ousob.com --- Legacy Redefined OuSob - File: /wwwroot/clipx/usr/include/htdig/WordKeyInfo.h

// WordKeyInfo.h // // NAME // information on the key structure of the inverted index. // // SYNOPSIS // // Use the WordKey::NField() method instead. // // DESCRIPTION // // Describe the structure of the index key (<i>WordKey</i>). // The description includes the layout of the packed version // stored on disk. // // CONFIGURATION // // wordlist_wordkey_description <desc> (no default) // Describe the structure of the inverted index key. // In the following explanation of the <i><desc></i> format // mandatory words are // in bold and values that must be replaced in italic. // <br> // <b>Word</b>/<i>name bits</i>[/...] // <br> // The <i>name</i> is an alphanumerical symbolic name for the key field. // The <i>bits</i> is the number of bits required to store this field. // Note that all values are stored in unsigned integers (unsigned int). // // // END // // Part of the ht://Dig package <http://www.htdig.org/> // Copyright (c) 1999-2004 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> // // #ifndef _WordKeyInfo_h_ #define _WordKeyInfo_h_ #include "Configuration.h" // // Type number associated to each possible type for a key element // (type field of struct WordKeyInfo). // #define WORD_ISA_NUMBER 1 #define WORD_ISA_STRING 2 // // Maximum number of fields in a key description // #define WORD_KEY_MAX_NFIELDS 20 // // All numerical fields of the key are typed WordKeyNum. // Most of the code strongly assume that it is unsigned. // Mainly provided to be replaced by unsigned longlong WordKeyNum // for 64 bits machines. // typedef unsigned int WordKeyNum; // // Maximum number of bits in a field // #define WORD_KEY_MAXBITS ((int)(sizeof(WordKeyNum) * 8)) #define WORD_KEY_MAXVALUE ((WordKeyNum)~(WordKeyNum)0) // // Description of a single field // class WordKeyField { public: WordKeyField() { type = lowbits = lastbits = bytesize = bytes_offset = bits = bits_offset = 0; } // // Precompute information that will be needed to pack/unpack the key // to/from disk. // // The <previous> field is used to compute the position of the field // in packed string. <nname> is the symbolic name of the field // <nbits> is the number of bits actualy used in a number. // int SetNum(WordKeyField *previous, char *nname, int nbits); // // Set the one and only string field // int SetString(); // // Maximum possible value for this field. // WordKeyNum MaxValue() const { return bits >= WORD_KEY_MAXBITS ? WORD_KEY_MAXVALUE : ((1 << bits) - 1); } // // Debugging and printing // void Show(); String name; // Symbolic name of the field int type; // WORD_ISA_{STRING|NUMBER} // // 01234567012345670123456701234567 // +-------+-------+-------+-------+-- // 100101010011100111101011110 // ^^^ ^^^^^^ // | | // lowbits = 3 lastbits = 6 // int lowbits; int lastbits; int bytesize; // Number of bytes involved int bytes_offset; // Offset of first byte from start int bits; // Size of field in bits int bits_offset; // Offset of first bit from start }; // // Description of the key structure // class WordKeyInfo { public: WordKeyInfo(const Configuration& config); ~WordKeyInfo() { if(sort) delete [] sort; } // // Unique instance handlers // static void Initialize(const Configuration& config); static void InitializeFromString(const String &desc); static WordKeyInfo* Instance() { if(instance) return instance; fprintf(stderr, "WordKeyInfo::Instance: no instance\n"); return 0; } int Alloc(int nnfields); int Set(const String &desc); void Show(); // // Array describing the fields, in sort order. // WordKeyField *sort; // // Total number of fields // int nfields; // // Total number of bytes used by numerical fields // int num_length; // // Unique instance pointer // static WordKeyInfo* instance; }; #endif