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Diffstat (limited to 'debian/htdig/htdig-3.2.0b6/htword/WordKeyInfo.h')
| -rw-r--r-- | debian/htdig/htdig-3.2.0b6/htword/WordKeyInfo.h | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/debian/htdig/htdig-3.2.0b6/htword/WordKeyInfo.h b/debian/htdig/htdig-3.2.0b6/htword/WordKeyInfo.h new file mode 100644 index 00000000..039dbf4f --- /dev/null +++ b/debian/htdig/htdig-3.2.0b6/htword/WordKeyInfo.h @@ -0,0 +1,170 @@ +// 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 |