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cdesktop/cde/programs/dtinfo/DtMmdb/index/fast_mphf.h
2018-04-28 12:30:20 -06:00

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/*
* CDE - Common Desktop Environment
*
* Copyright (c) 1993-2012, The Open Group. All rights reserved.
*
* These libraries and programs are free software; you can
* redistribute them and/or modify them under the terms of the GNU
* Lesser General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* These libraries and programs are distributed in the hope that
* they will be useful, but WITHOUT ANY WARRANTY; without even the
* implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU Lesser General Public License for more
* details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with these libraries and programs; if not, write
* to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
* Floor, Boston, MA 02110-1301 USA
*/
/*
* $XConsortium: fast_mphf.h /main/5 1996/07/18 14:36:28 drk $
*
* Copyright (c) 1993 HAL Computer Systems International, Ltd.
* All rights reserved. Unpublished -- rights reserved under
* the Copyright Laws of the United States. USE OF A COPYRIGHT
* NOTICE IS PRECAUTIONARY ONLY AND DOES NOT IMPLY PUBLICATION
* OR DISCLOSURE.
*
* THIS SOFTWARE CONTAINS CONFIDENTIAL INFORMATION AND TRADE
* SECRETS OF HAL COMPUTER SYSTEMS INTERNATIONAL, LTD. USE,
* DISCLOSURE, OR REPRODUCTION IS PROHIBITED WITHOUT THE
* PRIOR EXPRESS WRITTEN PERMISSION OF HAL COMPUTER SYSTEMS
* INTERNATIONAL, LTD.
*
* RESTRICTED RIGHTS LEGEND
* Use, duplication, or disclosure by the Government is subject
* to the restrictions as set forth in subparagraph (c)(l)(ii)
* of the Rights in Technical Data and Computer Software clause
* at DFARS 252.227-7013.
*
* HAL COMPUTER SYSTEMS INTERNATIONAL, LTD.
* 1315 Dell Avenue
* Campbell, CA 95008
*
*/
#ifndef _fast_mphf_h
#define _fast_mphf_h 1
#include <sys/wait.h>
#include "index/hash.h"
#include "utility/atoi_pearson.h"
#include "object/long_pstring.h"
#include "utility/xtime.h"
#include "hmphf/mphf_funcs.h"
#include "hmphf/sorter.h"
///////////////////////////////////////////////////////////////
// A fast MPHF contruct method proposed by Chen Qi Fan in 4/91.
// Usually it will compute MPHFs using 2-3 bits/key.
// Random number table size is reduced to 128 chars.
// Computation is fast due to the pattern matching
// used in the searching stage.
//
// Reference: VaTech Technical Report TR92-2, SIGIR92 paper.
//
// Modification:
// convert to mmdb version (task started on 9-15-92)
///////////////////////////////////////////////////////////////
class tbl_record
{
public:
int v_seed;
atoi_pearson* v_tbl0;
atoi_pearson* v_tbl1;
public:
tbl_record(int sd = 0, atoi_pearson* t1 =0, atoi_pearson* t2 =0) :
v_seed(sd), v_tbl0(t1), v_tbl1(t2) {};
~tbl_record();
};
class tbl_cache
{
protected:
void_ptr_array f_array;
public:
tbl_cache();
~tbl_cache();
void init_table(int hash_table_sz, int seed, atoi_pearson*&, atoi_pearson*&);
friend class fast_mphf;
};
class fast_mphf : public long_pstring, public ihash
{
public:
fast_mphf(c_code_t = FAST_MPHF_CODE);
virtual ~fast_mphf();
MMDB_SIGNATURES(fast_mphf);
void init_persistent_info(persistent_info*);
// init the two ascii->integer map tables
Boolean init_map_tbls();
// load the MPHF from files
using pstring::asciiIn;
virtual io_status asciiIn(istream&);
// compute a hash value for a key.
virtual int hashTo(const key_type&);
// compute a MPHF
virtual Boolean build(const char* data_path);
virtual Boolean build(istream& data_stream);
// show the mapping from keys to hash values and verify the mphf.
// option = 0: no print, only check;
// option = 1: print and check.
void print_mapping( const char*key_file, int option = 0) ;
void print_gvalues(ostream&out = cerr) ;
virtual int cdr_sizeof();
virtual io_status cdrOut(buffer&);
virtual io_status cdrIn(buffer&);
protected:
// return the ith g value from the g array (in packed form)
int gValue(int, int& gvalue, int& ctl_bit) ;
void print_tbls(ostream&out = cerr) ;
int print_bits(unsigned, ostream& = cout);
protected:
#ifdef C_API
static tbl_cache *v_tbl_cache_ptr;
#else
static tbl_cache v_tbl_cache;
#endif
atoi_pearson *v_tbl0 , // table1
*v_tbl1 ; // table2
Boolean v_long_string_core_indexed;
unsigned int v_no_ps, // number of partitions (buckets)
v_p1, v_p2, // parameters p1 and p2.
r,
v_seed,
t;
};
HANDLER_SIGNATURES(fast_mphf)
#endif