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cdesktop/cde/lib/DtMmdb/hmphf/mphf_funcs.C

382 lines
9.2 KiB
C

/*
* 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: mphf_funcs.cc /main/4 1996/07/18 14:33:08 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 Unpublished -- rights reserved under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
*
*/
#include "hmphf/mphf_funcs.h"
#define NO_BACKTRACKS 50
#define NO_MAPPINGS 20
#define NO_SEARCHINGS 10
//compute_a_mphf(char* key_file, params& pms, char* mphf_spec_file)
int compute_a_mphf(char** keys, params& pms, buffer& mphf_buffer)
{
mphf_hash_table ht(pms);
int i, k;
for ( k=0; k<NO_MAPPINGS; k++ ) {
//buckets bs(key_file, pms);
buckets bs(keys, pms);
//MESSAGE(cerr, "buckets built");
/* search for a MPHF */
for ( i = 0; i<NO_SEARCHINGS; i++) {
//MESSAGE(cerr, form("%dth search:", i+1));
bs.set_control_bit(-1);
ht.clear();
if ( search(bs, ht, pms) == 0 ) {
//MESSAGE(cerr, "search done");
/* verify computed MPHF */
if ( verify(bs, ht, pms) == 0 ) {
/* output the computed MPHF */
return write_spec(bs, pms, mphf_buffer);
} else {
return -1;
}
}
}
pms.v_r++;
}
return 1;
}
int search(buckets& bs, mphf_hash_table& ht, params& pms)
{
int i = 0,
fails = 0,
patternFit = 0;
int num_backtracks = 0;
int no_search_fails = bs.no_buckets() / 2;
int_pattern new_pattern(bs.max_bucket_sz());
while ( i < bs.no_buckets() && fails < no_search_fails ) {
if ( bs[i] == 0 || bs[i] -> no_keys() == 0 ) {
i++;
continue;
};
patternFit = -1;
//MESSAGE(cerr, "before fit");
while ( bs.get_pattern(i, new_pattern, pms) == 0 ) {
//debug(cerr, new_pattern);
//cerr << new_pattern.no_elmts();
patternFit = ht.fast_fit(new_pattern);
if ( patternFit >= 0 ) {
//MESSAGE(cerr, " fit");
bs[i] -> set_g_value(patternFit);
break;
} else {
//MESSAGE(cerr, " fail");
fails++;
}
}
if ( patternFit == -1 ) {
//MESSAGE(cerr, "BACKTRACK");
if ( i <= 0 ) break;
i--;
//fails = 0;
if ( num_backtracks > bs.no_buckets() ) {
return -2;
} else
num_backtracks++;
} else {
//MESSAGE(cerr, "increment i");
i++;
}
}
return ( patternFit >= 0 ) ? 0 : -1;
}
int verify(buckets& bs, mphf_hash_table& ht, params& pms)
{
int i;
int_pattern new_pattern(bs.max_bucket_sz());
//debug(cerr, ht.num_filled_slots());
//debug(cerr, ht.no_slots());
//debug(cerr, pms.n);
if ( ht.num_filled_slots() != ht.no_slots() ) {
MESSAGE(cerr, "panic: hash table not full or 'too' full");
MESSAGE(cerr, form("filled_slots = %d\n", ht.num_filled_slots()));
MESSAGE(cerr, form("no_slots = %d\n", ht.no_slots()));
return -1;
}
ht.clear();
for ( i = 0; i < bs.no_buckets(); i++ ) {
if ( bs[i] == 0 || bs[i] -> no_keys() == 0 ) continue;
bs.use_current_params(i, new_pattern, pms, true);
//debug(cerr, bs[i] -> orig_pos());
//debug(cerr, new_pattern);
if ( ht.fit_hash_table(new_pattern) != 0 ) {
MESSAGE(cerr, "panic: collision occurred");
return -1 ;
}
}
//debug(cerr, ht.num_filled_slots());
//debug(cerr, ht.no_slots());
if ( ht.num_filled_slots() != ht.no_slots() ) {
MESSAGE(cerr, "panic: hash table not full after test insertion");
MESSAGE(cerr, form("filled_slots = %d\n", ht.num_filled_slots()));
MESSAGE(cerr, form("no_slots = %d\n", ht.no_slots()));
return -1;
} else {
MESSAGE(cerr, "verifying OK");
return 0;
}
}
int write_spec(buckets& bs, params& pms, buffer& mphf_buffer)
{
unsigned int gv_bits = 0;
if ( pms.v_n > 0 ) {
gv_bits = (int)(flog2(pms.v_n)) + 1; /* bits of each g value.*/
if ( floor(flog2(pms.v_n)) < flog2(pms.v_n) )
gv_bits++;
}
int uints_of_cmpat_gv = gv_bits * pms.v_b;
if ( uints_of_cmpat_gv % BITS_IN(unsigned) > 0 )
uints_of_cmpat_gv += BITS_IN(unsigned);
uints_of_cmpat_gv /= BITS_IN(unsigned);
unsigned int *c_array = new unsigned[uints_of_cmpat_gv];
compact(bs, c_array, gv_bits, mphf_buffer.get_swap_order());
unsigned int g_array_bytes = sizeof(unsigned int) * uints_of_cmpat_gv;
int spec_bytes = 7 * ( sizeof(unsigned int) + 1) + g_array_bytes + 1;
mphf_buffer.expand_chunk(spec_bytes);
ostringstream fout(mphf_buffer.get_base(), ios::out);
fout << pms.v_n << "\n";
fout << pms.v_b << "\n";
fout << pms.v_p1 << "\n";
fout << pms.v_p2 << "\n";
fout << pms.v_r << "\n";
fout << pms.v_seed << "\n";
fout << g_array_bytes << '\t';
fout.write((char*)c_array, g_array_bytes);
fout << '\n';
int fout_len = fout.str().size();
mphf_buffer.set_content_sz(fout_len);
memcpy(mphf_buffer.get_base(), fout.str().c_str(), fout_len);
delete [] c_array;
return 0;
}
int compact(buckets& bs, unsigned s[], int t, Boolean swap)
{
int target, k, i, remaining_bits, branch = 0;
unsigned unsigned_g, high_part_bits;
unsigned lower_part_bits = 0;
remaining_bits = BITS_IN(unsigned);
k = target = 0;
unsigned* y = new unsigned[bs.no_buckets()];
for ( i = 0; i < bs.no_buckets(); y[i++] = 0 );
for ( i = 0; i < bs.no_buckets(); i++ ) {
if ( bs[i] && bs[i] -> no_keys() > 0 ) {
y[bs[i] -> orig_pos()] =
((bs[i] -> g_value()) << 1) + bs[i] -> control_bit();
/*
cerr << bs[i] -> orig_pos() << " ";
cerr << bs[i] -> g_value() << " ";
cerr << bs[i] -> control_bit() << " ";
cerr << y[bs[i] -> orig_pos()] << "\n";
*/
}
}
/*
MESSAGE(cerr, "=======BIT ARRAY:");
debug(cerr, bs.no_buckets());
for ( i = 0; i < bs.no_buckets(); i++ )
cerr << i << " " << y[i] << "\n";
cerr << "=======\n";
*/
//MESSAGE(cerr, "=======BIT ARRAY (before swap):");
for ( i = 0; i < bs.no_buckets(); i++ ) {
unsigned_g = y[i];
/*
debug(cerr, i);
debug(cerr, hex(unsigned_g));
*/
/*
debug(cerr, form("%x", c_bit));
debug(cerr, "=====");
*/
if (remaining_bits >= t ) {
unsigned_g <<= (remaining_bits -t);
target |= unsigned_g;
remaining_bits -= t;
branch = 0;
} else {
high_part_bits = getbits(unsigned_g,t,remaining_bits);
lower_part_bits = unsigned_g & ~(~0 << (t-remaining_bits));
lower_part_bits <<= (BITS_IN(unsigned)- (t-remaining_bits));
s[k++] = target | high_part_bits;
#ifdef PORTABLE_DB
if ( swap == true )
ORDER_SWAP_UINT(s[k-1]);
#endif
target = lower_part_bits;
remaining_bits = BITS_IN(unsigned) - ( t - remaining_bits );
branch =1;
}
}
if ( bs.no_buckets() > 0 ) {
s[k] = ( branch == 0 ) ? target : lower_part_bits;
#ifdef PORTABLE_DB
if ( swap == true )
ORDER_SWAP_UINT(s[k]);
#endif
}
/*
MESSAGE(cerr, "=======BIT ARRAY (after swap):");
debug(cerr, k+1);
for ( i = 0; i <= k; i++ )
cerr << i << " " << s[i] << "\n";
cerr << "=======\n";
*/
delete [] y;
return 0;
}
int wc(char* file_name, unsigned int& lines, unsigned int& max_length)
{
char buf[BUFSIZ];
fstream in(file_name, ios::in);
if ( !in ) {
MESSAGE(cerr, "can not open key file");
throw(streamException(in.rdstate()));
}
lines = 0;
max_length = 0;
while ( in.getline(buf, BUFSIZ) ) {
max_length = MAX(strlen(buf)-1, max_length);
lines++;
}
if ( lines == 0 ) {
MESSAGE(cerr, "empty key file");
return -1;
} else
return 0;
}