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Diffstat (limited to 'troff/symbol.cc')
| -rw-r--r-- | troff/symbol.cc | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/troff/symbol.cc b/troff/symbol.cc new file mode 100644 index 000000000..f8196a0be --- /dev/null +++ b/troff/symbol.cc @@ -0,0 +1,140 @@ +// -*- C++ -*- +/* Copyright (C) 1989, 1990, 1991, 1992 Free Software Foundation, Inc. + Written by James Clark (jjc@jclark.com) + +This file is part of groff. + +groff is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 2, or (at your option) any later +version. + +groff is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received a copy of the GNU General Public License along +with groff; see the file COPYING. If not, write to the Free Software +Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ + + +#include "troff.h" +#include "symbol.h" + +const char **symbol::table = 0; +int symbol::table_used = 0; +int symbol::table_size = 0; +char *symbol::block = 0; +int symbol::block_size = 0; + +const symbol NULL_SYMBOL; + +const int BLOCK_SIZE = 1024; +// the table will increase in size as necessary +// the size will be chosen from the following array +// add some more if you want +// I think it unlikely that we'll need more than a million symbols +static const unsigned int table_sizes[] = { +101, 503, 1009, 2003, 3001, 4001, 5003, 10007, 20011, 40009, 80021, 160001, 500009, 1000003, 0 +}; +const double FULL_MAX = 0.3; // don't let the table get more than this full + +static unsigned int hash_string(const char *p) +{ + // compute a hash code; this assumes 32-bit unsigned ints + // see p436 of Compilers by Aho, Sethi & Ullman + // give special treatment to two-character names + unsigned int hc = 0, g; + if (*p != 0) { + hc = *p++; + if (*p != 0) { + hc <<= 7; + hc += *p++; + for (; *p != 0; p++) { + hc <<= 4; + hc += *p; + if ((g = (hc & 0xf0000000)) == 0) { + hc ^= g >> 24; + hc ^= g; + } + } + } + } + return hc; +} + +symbol::symbol(const char *p, int how) +{ + if (p == 0 || *p == 0) { + s = 0; + return; + } + if (table == 0) { + table_size = table_sizes[0]; + table = new char*[table_size]; + for (int i = 0; i < table_size; i++) + table[i] = 0; + table_used = 0; + } + unsigned int hc = hash_string(p); + for (const char **pp = table + hc % table_size; + *pp != 0; + (pp == table ? pp = table + table_size - 1 : --pp)) + if (strcmp(p, *pp) == 0) { + s = *pp; + return; + } + if (how == MUST_ALREADY_EXIST) { + s = 0; + return; + } + if (table_used >= table_size - 1 || table_used >= table_size*FULL_MAX) { + const char **old_table = table; + unsigned int old_table_size = table_size; + for (int i = 1; table_sizes[i] <= old_table_size; i++) + if (table_sizes[i] == 0) + fatal("too many symbols"); + table_size = table_sizes[i]; + table_used = 0; + table = new char*[table_size]; + for (i = 0; i < table_size; i++) + table[i] = 0; + for (pp = old_table + old_table_size - 1; + pp >= old_table; + --pp) { + symbol temp(*pp, 1); /* insert it into the new table */ + } + a_delete old_table; + for (pp = table + hc % table_size; + *pp != 0; + (pp == table ? pp = table + table_size - 1 : --pp)) + ; + } + ++table_used; + if (how == DONT_STORE) { + s = *pp = p; + } + else { + int len = strlen(p)+1; + if (block == 0 || block_size < len) { + block_size = len > BLOCK_SIZE ? len : BLOCK_SIZE; + block = new char [block_size]; + } + (void)strcpy(block, p); + s = *pp = block; + block += len; + block_size -= len; + } +} + +symbol concat(symbol s1, symbol s2) +{ + char *buf = new char [strlen(s1.contents()) + strlen(s2.contents()) + 1]; + strcpy(buf, s1.contents()); + strcat(buf, s2.contents()); + symbol res(buf); + a_delete buf; + return res; +} + |