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Rework the hash table code.

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This commit is contained in:
Bruno Haible
2002-12-19 12:35:17 +00:00
parent 388a431c7d
commit 1186e616cb
4 changed files with 163 additions and 77 deletions
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94
src/search.cc
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@@ -31,9 +31,6 @@
#include "options.h"
#include "hash-table.h"
/* Make the hash table 8 times larger than the number of keyword entries. */
static const int TABLE_MULTIPLE = 10;
/* Efficiently returns the least power of two greater than or equal to X! */
#define POW(X) ((!X)?1:(X-=1,X|=X>>1,X|=X>>2,X|=X>>4,X|=X>>8,X|=X>>16,(++X)))
@@ -50,7 +47,6 @@ void
Search::prepare ()
{
KeywordExt_List *temp;
KeywordExt_List *trail = NULL;
_total_keys = 0;
for (temp = _head; temp; temp = temp->rest())
@@ -58,59 +54,57 @@ Search::prepare ()
temp->first()->init_selchars(_occurrences);
_total_keys++;
}
/* Hash table this number of times larger than keyword number. */
int table_size = (_list_len = _total_keys) * TABLE_MULTIPLE;
/* Table must be a power of 2 for the hash function scheme to work. */
KeywordExt **table = new KeywordExt*[POW (table_size)];
/* Make large hash table for efficiency. */
Hash_Table found_link (table, table_size, option[NOLENGTH]);
_list_len = _total_keys;
/* Test whether there are any links and also set the maximum length of
an identifier in the keyword list. */
_total_duplicates = 0;
_max_key_len = INT_MIN;
_min_key_len = INT_MAX;
for (temp = _head; temp; temp = temp->rest())
{
KeywordExt *keyword = temp->first();
KeywordExt *other_keyword = found_link.insert (keyword);
{
/* Make hash table for efficiency. */
Hash_Table found_link (_list_len, option[NOLENGTH]);
/* Check for links. We deal with these by building an equivalence class
of all duplicate values (i.e., links) so that only 1 keyword is
representative of the entire collection. This *greatly* simplifies
processing during later stages of the program. */
/* Test whether there are any links and also set the maximum length of
an identifier in the keyword list. */
_total_duplicates = 0;
_max_key_len = INT_MIN;
_min_key_len = INT_MAX;
KeywordExt_List *trail = NULL;
for (temp = _head; temp; temp = temp->rest())
{
KeywordExt *keyword = temp->first();
KeywordExt *other_keyword = found_link.insert (keyword);
if (other_keyword)
{
_total_duplicates++;
_list_len--;
trail->rest() = temp->rest();
temp->first()->_duplicate_link = other_keyword->_duplicate_link;
other_keyword->_duplicate_link = temp->first();
/* Check for links. We deal with these by building an equivalence class
of all duplicate values (i.e., links) so that only 1 keyword is
representative of the entire collection. This *greatly* simplifies
processing during later stages of the program. */
/* Complain if user hasn't enabled the duplicate option. */
if (!option[DUP] || option[DEBUG])
fprintf (stderr, "Key link: \"%.*s\" = \"%.*s\", with key set \"%.*s\".\n",
keyword->_allchars_length, keyword->_allchars,
other_keyword->_allchars_length, other_keyword->_allchars,
keyword->_selchars_length, keyword->_selchars);
}
else
{
temp->first()->_duplicate_link = NULL;
trail = temp;
}
if (other_keyword)
{
_total_duplicates++;
_list_len--;
trail->rest() = temp->rest();
temp->first()->_duplicate_link = other_keyword->_duplicate_link;
other_keyword->_duplicate_link = temp->first();
/* Update minimum and maximum keyword length, if needed. */
if (_max_key_len < keyword->_allchars_length)
_max_key_len = keyword->_allchars_length;
if (_min_key_len > keyword->_allchars_length)
_min_key_len = keyword->_allchars_length;
}
/* Complain if user hasn't enabled the duplicate option. */
if (!option[DUP] || option[DEBUG])
fprintf (stderr, "Key link: \"%.*s\" = \"%.*s\", with key set \"%.*s\".\n",
keyword->_allchars_length, keyword->_allchars,
other_keyword->_allchars_length, other_keyword->_allchars,
keyword->_selchars_length, keyword->_selchars);
}
else
{
temp->first()->_duplicate_link = NULL;
trail = temp;
}
delete[] table;
/* Update minimum and maximum keyword length, if needed. */
if (_max_key_len < keyword->_allchars_length)
_max_key_len = keyword->_allchars_length;
if (_min_key_len > keyword->_allchars_length)
_min_key_len = keyword->_allchars_length;
}
}
/* Exit program if links exists and option[DUP] not set, since we can't continue */
if (_total_duplicates)