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Diffstat (limited to 'contrib/gperf/src/list-node.cc')
-rw-r--r-- | contrib/gperf/src/list-node.cc | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/contrib/gperf/src/list-node.cc b/contrib/gperf/src/list-node.cc new file mode 100644 index 000000000000..6c7888976e13 --- /dev/null +++ b/contrib/gperf/src/list-node.cc @@ -0,0 +1,101 @@ +/* Creates and initializes a new list node. + Copyright (C) 1989-1998 Free Software Foundation, Inc. + written by Douglas C. Schmidt (schmidt@ics.uci.edu) + +This file is part of GNU GPERF. + +GNU GPERF 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 1, or (at your option) +any later version. + +GNU GPERF 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 GNU GPERF; see the file COPYING. If not, write to the Free +Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111, USA. */ + +#include "list-node.h" + +#include <stdio.h> +#include <stdlib.h> /* declares exit() */ +#include "options.h" +#include "trace.h" + +/* Sorts the key set alphabetically to speed up subsequent operations. + Uses insertion sort since the set is probably quite small. */ + +inline void +List_Node::set_sort (char *base, int len) +{ + T (Trace t ("List_Node::set_sort");) + int i, j; + + for (i = 0, j = len - 1; i < j; i++) + { + char curr, tmp; + + for (curr = i + 1, tmp = base[curr]; curr > 0 && tmp < base[curr-1]; curr--) + base[curr] = base[curr - 1]; + + base[curr] = tmp; + + } +} + +/* Initializes a List_Node. This requires obtaining memory for the CHAR_SET + initializing them using the information stored in the KEY_POSITIONS array in Options, + and checking for simple errors. It's important to note that KEY and REST are + both pointers to the different offsets into the same block of dynamic memory pointed + to by parameter K. The data member REST is used to store any additional fields + of the input file (it is set to the "" string if Option[TYPE] is not enabled). + This is useful if the user wishes to incorporate a lookup structure, + rather than just an array of keys. Finally, KEY_NUMBER contains a count + of the total number of keys seen so far. This is used to initialize + the INDEX field to some useful value. */ + +List_Node::List_Node (char *k, int len): link (0), next (0), + key (k), rest (option[TYPE] ? k + len + 1 : ""), length (len), index (0) +{ + T (Trace t ("List_Node::List_Node");) + char *ptr = new char[(option[ALLCHARS] ? len : option.get_max_keysig_size ()) + 1]; + char *key_set = ptr; + k[len] = '\0'; /* Null terminate KEY to separate it from REST. */ + + if (option[ALLCHARS]) /* Use all the character position in the KEY. */ + for (; *k; k++, ptr++) + ++occurrences[(unsigned char)(*ptr = *k)]; + else /* Only use those character positions specified by the user. */ + { + int i; + + /* Iterate thru the list of key_positions, initializing occurrences table + and char_set (via char * pointer ptr). */ + + for (option.reset (); (i = option.get ()) != EOS; ) + { + if (i == WORD_END) /* Special notation for last KEY position, i.e. '$'. */ + *ptr = key[len - 1]; + else if (i <= len) /* Within range of KEY length, so we'll keep it. */ + *ptr = key[i - 1]; + else /* Out of range of KEY length, so we'll just skip it. */ + continue; + ++occurrences[(unsigned char)(*ptr++)]; + } + + /* Didn't get any hits and user doesn't want to consider the + keylength, so there are essentially no usable hash positions! */ + if (ptr == char_set && option[NOLENGTH]) + { + fprintf (stderr, "Can't hash keyword %s with chosen key positions.\n", key); + exit (1); + } + } + *ptr = '\0'; /* Terminate this bastard.... */ + /* Sort the KEY_SET items alphabetically. */ + set_sort (key_set, ptr - key_set); + char_set = key_set; +} |