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Allow the use of embedded NULs in keys.

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This commit is contained in:
Bruno Haible
2000-08-20 16:50:54 +00:00
parent cb286153b2
commit c0eb520394
10 changed files with 345 additions and 136 deletions
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36
src/hash-table.cc
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@@ -1,5 +1,5 @@
/* Hash table for checking keyword links. Implemented using double hashing.
Copyright (C) 1989-1998 Free Software Foundation, Inc.
Copyright (C) 1989-1998, 2000 Free Software Foundation, Inc.
written by Douglas C. Schmidt (schmidt@ics.uci.edu)
This file is part of GNU GPERF.
@@ -26,8 +26,6 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111, USA. */
#include "options.h"
#include "trace.h"
#define NIL(TYPE) (TYPE *)0
/* The size of the hash table is always the smallest power of 2 >= the size
indicated by the user. This allows several optimizations, including
the use of double hashing and elimination of the mod instruction.
@@ -37,8 +35,8 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111, USA. */
This compromises information hiding somewhat, but greatly reduces
memory fragmentation, since we can now use alloca! */
Hash_Table::Hash_Table (List_Node **table_ptr, int s):
table (table_ptr), size (s), collisions (0)
Hash_Table::Hash_Table (List_Node **table_ptr, int s, int ignore_len):
table (table_ptr), size (s), collisions (0), ignore_length (ignore_len)
{
T (Trace t ("Hash_Table::Hash_Table");)
memset ((char *) table, 0, size * sizeof (*table));
@@ -60,8 +58,10 @@ Hash_Table::~Hash_Table (void)
for (int i = size - 1; i >= 0; i--)
if (table[i])
fprintf (stderr, "%8d, %*s, %s\n",
i, field_width, table[i]->char_set, table[i]->key);
fprintf (stderr, "%8d, %*.*s, %.*s\n",
i,
field_width, table[i]->char_set_length, table[i]->char_set,
table[i]->key_length, table[i]->key);
fprintf (stderr, "\nend dumping hash table\n\n");
}
@@ -72,20 +72,24 @@ Hash_Table::~Hash_Table (void)
Uses double hashing. */
List_Node *
Hash_Table::operator() (List_Node *item, int ignore_length)
Hash_Table::insert (List_Node *item)
{
T (Trace t ("Hash_Table::operator()");)
unsigned hash_val = hashpjw (item->char_set);
int probe = hash_val & size - 1;
int increment = (hash_val ^ item->length | 1) & size - 1;
unsigned hash_val = hashpjw (item->char_set, item->char_set_length);
int probe = hash_val & (size - 1);
int increment = ((hash_val ^ item->key_length) | 1) & (size - 1);
while (table[probe]
&& (strcmp (table[probe]->char_set, item->char_set)
|| (!ignore_length && table[probe]->length != item->length)))
while (table[probe])
{
if (table[probe]->char_set_length == item->char_set_length
&& memcmp (table[probe]->char_set, item->char_set, item->char_set_length) == 0
&& (ignore_length || table[probe]->key_length == item->key_length))
return table[probe];
collisions++;
probe = probe + increment & size - 1;
probe = (probe + increment) & (size - 1);
}
return table[probe] ? table[probe] : (table[probe] = item, NIL (List_Node));
table[probe] = item;
return (List_Node *) 0;
}