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/* $Id: Keys.cpp,v 1.4 2003/06/23 14:38:41 terpstra Exp $
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* Keys.cpp - Digest a hunk of string into keywords.
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* Copyright (C) 2002 - Wesley W. Terpstra
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* Authors: 'Wesley W. Terpstra' <wesley@terpstra.ca>
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2.
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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#define _XOPEN_SOURCE 500
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#define _FILE_OFFSET_BITS 64
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/*------------------------------------------------ Private global vars */
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/* These are characters which should be interpretted as both part of the word
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* and as a word seperator. eg: 'maul.sith.vpn' should be indexed as 'maul',
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* 'sith', 'vpn', and 'maul.sith.vpn' because '.' is listed here.
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static const char my_keyword_word_splits[] = "$@./:\\-_~&=%?#+";
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static char my_keyword_is_split[256];
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/* These are characters which should be interpretted as word breaks.
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* No known language should use these as letters in a word.
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* All chars 000-037 fall in this category too.
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static const char my_keyword_word_divs[] = " !\"'()*,;<>[]^`{|}";
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static char my_keyword_is_div[256];
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/* These tables are the conversion for characters being written to keywords.
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static const char my_keyword_orig[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
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static const char my_keyword_dest[] = "abcdefghijklmnopqrstuvwxyz";
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static char my_keyword_conv[256];
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/* We need to be initd */
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static int my_keyword_initd = 1;
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/*------------------------------------------------ Private helper methods */
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/* Combine the prefix with the substring */
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static int my_keyword_index_hunk(
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const unsigned char* buf,
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const unsigned char* eos,
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int (*writefn)(const char* keyword, void* arg),
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char out[LU_KEYWORD_LEN+1];
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{ /* Don't index nothing */
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/* A quick check to avoid function calls */
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strcpy(&out[0], prefix);
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w = &out[strlen(prefix)];
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e = &out[sizeof(out) - 1];
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/* Copy the range into the buffer while converting it */
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while (w != e && buf != eos)
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*w++ = my_keyword_conv[*buf++];
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/* Ignore this keyword */
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return writefn(&out[0], arg);
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/* Look at a section of non-whitespace chars and decide what to do with it. */
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static int my_keyword_digest_hunk(
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const unsigned char* buf,
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const unsigned char* eos,
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int (*writefn)(const char* keyword, void* arg),
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const unsigned char* start;
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const unsigned char* scan;
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/*!!! Make me work with non-romanian languages (eg. japanese) */
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/* Japanese has no spaces to delineate words */
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/* Don't index vapour.
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/* Firstly, index the entire chunk, with leading and trailing chars.
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/* Index the entire hunk. */
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if (my_keyword_index_hunk(buf, eos, prefix, writefn, arg) != 0)
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if (!do_div) return 0;
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/* Now, divide the chunk into bits which we will keyword index */
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for (scan = buf; scan != eos; scan++)
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if (my_keyword_is_split[*scan])
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if (my_keyword_index_hunk(start, scan,
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prefix, writefn, arg) != 0)
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if (my_keyword_index_hunk(start, eos, prefix, writefn, arg) != 0)
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static void my_keyword_init(void)
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/* Clear the lookup tables */
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memset(&my_keyword_is_split[0], 0, sizeof(my_keyword_is_split));
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memset(&my_keyword_is_div [0], 0, sizeof(my_keyword_is_div));
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/* Bootstrap the lookup tables */
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for (i = 0; i < sizeof(my_keyword_word_splits)-1; i++)
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my_keyword_is_split[((int)my_keyword_word_splits[i])] = 1;
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for (i = 0; i < sizeof(my_keyword_word_divs)-1; i++)
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my_keyword_is_div[((int)my_keyword_word_divs[i])] = 1;
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/* All control characters divide words */
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for (i = 0; i < 040; i++)
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my_keyword_is_div[i] = 1;
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/* Initialize conversion table */
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for (i = 0; i < 256; i++)
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my_keyword_conv[i] = i;
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/* Fill the conversion entries */
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for (i = 0; i < sizeof(my_keyword_orig)-1; i++)
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my_keyword_conv[((int)my_keyword_orig[i])] =
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my_keyword_initd = 0;
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/*------------------------------------------------- Public component methods */
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/* Run through a buffer looking for segments of non-divide characters.
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int my_keyword_digest_string(
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int (*writefn)(const char* keyword, void* arg),
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const unsigned char* start;
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const unsigned char* scan;
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const unsigned char* eos = (const unsigned char*)buf + len;
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if (my_keyword_initd)
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for (scan = (const unsigned char*)buf; scan != eos; scan++)
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if (my_keyword_is_div[*scan])
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my_keyword_digest_hunk(start, scan,
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prefix, writefn, arg, do_div);
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my_keyword_digest_hunk(start, eos, prefix, writefn, arg, do_div);
added
removed
common/Keys.cpp
