Adwaith-Rajesh/gperf
1
0
Fork 0
mirror of https://git.savannah.gnu.org/git/gperf.git synced 2025-12-02 13:09:22 +00:00
Code Activity

Move the search algorithm to search.h, search.cc.

Browse Source
This commit is contained in:
Bruno Haible
2002-11-26 12:48:39 +00:00
parent 122b13cc95
commit aca3f4abae
11 changed files with 747 additions and 864 deletions
Download Patch File Download Diff File Expand all files Collapse all files

21
ChangeLog
View File

@@ -1,5 +1,26 @@
2002-11-02 Bruno Haible <bruno@clisp.org> 2002-11-02 Bruno Haible <bruno@clisp.org>
* src/search.h: New file, combines src/key-list.h, src/gen-perf.h.
* src/search,cc: New file, combines src/key-list.cc, src/gen-perf.cc.
* src/key-list.h: Remove file.
* src/key-list.cc: Remove file.
* src/gen-perf.h: Remove file.
* src/gen-perf.cc: Remove file.
* src/main.cc (KeywordExt_Factory): Moved here from gen-perf.cc.
(main): Inline some code from gen-perf.cc.
* src/keyword.h (KeywordExt::init_selchars): Take the occurrences
vector as argument.
* src/keyword.cc (KeywordExt::init_selchars): Take the occurrences
vector as argument.
* src/input.cc (Input::set_output_types): Initialize _array_type,
_return_type, _struct_tag.
(Input::read_keys): Initialize _additional_code.
* src/Makefile.in (OBJECTS): Add search.o.
Remove key-list.o, gen-perf.o.
(KEY_LIST_H, GEN_PERF_H): Remove variables.
(gen-perf.o, key-list.o): Remove rules.
(search.o): New rule.
* *, */*: Update copyright notice to GPL version 2. * *, */*: Update copyright notice to GPL version 2.
* src/keyword-list.h (Keyword_List): New class. * src/keyword-list.h (Keyword_List): New class.

12
src/Makefile.in
View File

@@ -61,9 +61,9 @@ SHELL = /bin/sh
VPATH = $(srcdir) VPATH = $(srcdir)
OBJECTS = options.o main.o gen-perf.o key-list.o \ OBJECTS = options.o main.o \
hash-table.o bool-array.o read-line.o vectors.o version.o \ hash-table.o bool-array.o read-line.o vectors.o version.o \
keyword.o keyword-list.o output.o input.o keyword.o keyword-list.o output.o input.o search.o
LIBS = ../lib/libgp.a @GPERF_LIBM@ LIBS = ../lib/libgp.a @GPERF_LIBM@
CPPFLAGS = -I. -I$(srcdir)/../lib CPPFLAGS = -I. -I$(srcdir)/../lib
@@ -89,19 +89,13 @@ VERSION_H = version.h
VECTORS_H = vectors.h VECTORS_H = vectors.h
READ_LINE_H = read-line.h read-line.icc READ_LINE_H = read-line.h read-line.icc
OPTIONS_H = options.h options.icc OPTIONS_H = options.h options.icc
KEY_LIST_H = key-list.h $(VECTORS_H) $(READ_LINE_H)
HASH_TABLE_H = hash-table.h HASH_TABLE_H = hash-table.h
BOOL_ARRAY_H = bool-array.h bool-array.icc $(OPTIONS_H) BOOL_ARRAY_H = bool-array.h bool-array.icc $(OPTIONS_H)
GEN_PERF_H = gen-perf.h $(KEY_LIST_H) $(BOOL_ARRAY_H)
bool-array.o : bool-array.cc $(BOOL_ARRAY_H) $(OPTIONS_H) bool-array.o : bool-array.cc $(BOOL_ARRAY_H) $(OPTIONS_H)
$(CXX) $(CXXFLAGS) $(CPPFLAGS) -c $(srcdir)/bool-array.cc $(CXX) $(CXXFLAGS) $(CPPFLAGS) -c $(srcdir)/bool-array.cc
gen-perf.o : gen-perf.cc $(GEN_PERF_H) $(OPTIONS_H)
$(CXX) $(CXXFLAGS) $(CPPFLAGS) -c $(srcdir)/gen-perf.cc
hash-table.o : hash-table.cc $(HASH_TABLE_H) $(OPTIONS_H) hash-table.o : hash-table.cc $(HASH_TABLE_H) $(OPTIONS_H)
$(CXX) $(CXXFLAGS) $(CPPFLAGS) -c $(srcdir)/hash-table.cc $(CXX) $(CXXFLAGS) $(CPPFLAGS) -c $(srcdir)/hash-table.cc
key-list.o : key-list.cc $(KEY_LIST_H) $(OPTIONS_H) $(READ_LINE_H) $(HASH_TABLE_H) $(VERSION_H)
$(CXX) $(CXXFLAGS) $(CPPFLAGS) -c $(srcdir)/key-list.cc
main.o : main.cc $(OPTIONS_H) $(GEN_PERF_H) $(CONFIG_H) main.o : main.cc $(OPTIONS_H) $(GEN_PERF_H) $(CONFIG_H)
$(CXX) $(CXXFLAGS) $(CPPFLAGS) -c $(srcdir)/main.cc $(CXX) $(CXXFLAGS) $(CPPFLAGS) -c $(srcdir)/main.cc
options.o : options.cc $(OPTIONS_H) $(VECTORS_H) $(VERSION_H) options.o : options.cc $(OPTIONS_H) $(VECTORS_H) $(VERSION_H)
@@ -120,6 +114,8 @@ output.o : output.cc output.h
$(CXX) $(CXXFLAGS) $(CPPFLAGS) -c $(srcdir)/output.cc $(CXX) $(CXXFLAGS) $(CPPFLAGS) -c $(srcdir)/output.cc
input.o : input.cc input.h input.o : input.cc input.h
$(CXX) $(CXXFLAGS) $(CPPFLAGS) -c $(srcdir)/input.cc $(CXX) $(CXXFLAGS) $(CPPFLAGS) -c $(srcdir)/input.cc
search.o : search.cc search.h
$(CXX) $(CXXFLAGS) $(CPPFLAGS) -c $(srcdir)/search.cc
install : all force install : all force
$(MKINSTALLDIRS) $(DESTDIR)$(bindir) $(MKINSTALLDIRS) $(DESTDIR)$(bindir)

363
src/gen-perf.cc
View File

@@ -1,363 +0,0 @@
/* Provides high-level routines to manipulate the keywork list
structures the code generation output.
Copyright (C) 1989-1998, 2000, 2002 Free Software Foundation, Inc.
Written by Douglas C. Schmidt <schmidt@ics.uci.edu>
and Bruno Haible <bruno@clisp.org>.
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 2, 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 this program; see the file COPYING.
If not, write to the Free Software Foundation, Inc.,
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#include <stdio.h>
#include <stdlib.h> /* declares rand(), srand() */
#include <time.h> /* declares time() */
#include "options.h"
#include "gen-perf.h"
#include "output.h"
/* 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)))
/* Reads input keys, possibly applies the reordering heuristic, sets the
maximum associated value size (rounded up to the nearest power of 2),
may initialize the associated values array, and determines the maximum
hash table size. Note: using the random numbers is often helpful,
though not as deterministic, of course! */
Gen_Perf::Gen_Perf ()
{
int asso_value_max;
int non_linked_length;
Vectors::ALPHA_SIZE = (option[SEVENBIT] ? 128 : 256);
read_keys ();
if (option[ORDER])
reorder ();
_num_done = 1;
_fewest_collisions = 0;
asso_value_max = option.get_size_multiple ();
non_linked_length = Key_List::keyword_list_length ();
if (asso_value_max == 0)
asso_value_max = non_linked_length;
else if (asso_value_max > 0)
asso_value_max *= non_linked_length;
else /* if (asso_value_max < 0) */
asso_value_max = non_linked_length / -asso_value_max;
set_asso_max (POW (asso_value_max));
if (option[RANDOM])
{
srand (reinterpret_cast<long>(time (0)));
for (int i = 0; i < ALPHA_SIZE; i++)
_asso_values[i] = (rand () & asso_value_max - 1);
}
else
{
int asso_value = option.get_initial_asso_value ();
if (asso_value) /* Initialize array if user requests non-zero default. */
for (int i = ALPHA_SIZE - 1; i >= 0; i--)
_asso_values[i] = asso_value & get_asso_max () - 1;
}
_max_hash_value = Key_List::max_key_length () + get_asso_max () *
get_max_keysig_size ();
_collision_detector = new Bool_Array (_max_hash_value + 1);
if (option[DEBUG])
fprintf (stderr, "total non-linked keys = %d\nmaximum associated value is %d"
"\nmaximum size of generated hash table is %d\n",
non_linked_length, asso_value_max, _max_hash_value);
}
/* Merge two disjoint hash key multisets to form the ordered disjoint union of the sets.
(In a multiset, an element can occur multiple times.)
Precondition: both set_1 and set_2 must be ordered. Returns the length
of the combined set. */
inline int
Gen_Perf::compute_disjoint_union (const char *set_1, int size_1, const char *set_2, int size_2, char *set_3)
{
char *base = set_3;
while (size_1 > 0 && size_2 > 0)
if (*set_1 == *set_2)
set_1++, size_1--, set_2++, size_2--;
else
{
char next;
if (*set_1 < *set_2)
next = *set_1++, size_1--;
else
next = *set_2++, size_2--;
if (set_3 == base || next != set_3[-1])
*set_3++ = next;
}
while (size_1 > 0)
{
char next;
next = *set_1++, size_1--;
if (set_3 == base || next != set_3[-1])
*set_3++ = next;
}
while (size_2 > 0)
{
char next;
next = *set_2++, size_2--;
if (set_3 == base || next != set_3[-1])
*set_3++ = next;
}
return set_3 - base;
}
/* Sort the UNION_SET in increasing frequency of occurrence.
This speeds up later processing since we may assume the resulting
set (Set_3, in this case), is ordered. Uses insertion sort, since
the UNION_SET is typically short. */
inline void
Gen_Perf::sort_set (char *union_set, int len)
{
int i, j;
for (i = 0, j = len - 1; i < j; i++)
{
int curr;
char tmp;
for (curr = i + 1, tmp = union_set[curr];
curr > 0 && _occurrences[static_cast<unsigned char>(tmp)] < _occurrences[static_cast<unsigned char>(union_set[curr-1])];
curr--)
union_set[curr] = union_set[curr - 1];
union_set[curr] = tmp;
}
}
/* Generate a key set's hash value. */
inline int
Gen_Perf::hash (KeywordExt *key_node)
{
int sum = option[NOLENGTH] ? 0 : key_node->_allchars_length;
const char *p = key_node->_selchars;
int i = key_node->_selchars_length;
for (; i > 0; p++, i--)
sum += _asso_values[static_cast<unsigned char>(*p)];
return key_node->_hash_value = sum;
}
/* Find out how character value change affects successfully hashed items.
Returns FALSE if no other hash values are affected, else returns TRUE.
Note that because Option.Get_Asso_Max is a power of two we can guarantee
that all legal Asso_Values are visited without repetition since
Option.Get_Jump was forced to be an odd value! */
inline bool
Gen_Perf::affects_prev (char c, KeywordExt *curr)
{
int original_char = _asso_values[static_cast<unsigned char>(c)];
int total_iterations = !option[FAST]
? get_asso_max () : option.get_iterations () ? option.get_iterations () : keyword_list_length ();
/* Try all legal associated values. */
for (int i = total_iterations - 1; i >= 0; i--)
{
int collisions = 0;
_asso_values[static_cast<unsigned char>(c)] =
(_asso_values[static_cast<unsigned char>(c)] + (option.get_jump () ? option.get_jump () : rand ()))
& (get_asso_max () - 1);
/* Iteration Number array is a win, O(1) intialization time! */
_collision_detector->clear ();
/* See how this asso_value change affects previous keywords. If
it does better than before we'll take it! */
for (KeywordExt_List *ptr = _head; ; ptr = ptr->rest())
{
KeywordExt *keyword = ptr->first();
if (_collision_detector->set_bit (hash (keyword))
&& ++collisions >= _fewest_collisions)
break;
if (keyword == curr)
{
_fewest_collisions = collisions;
if (option[DEBUG])
fprintf (stderr, "- resolved after %d iterations", total_iterations - i);
return false;
}
}
}
/* Restore original values, no more tries. */
_asso_values[static_cast<unsigned char>(c)] = original_char;
/* If we're this far it's time to try the next character.... */
return true;
}
/* Change a character value, try least-used characters first. */
void
Gen_Perf::change (KeywordExt *prior, KeywordExt *curr)
{
static char *union_set;
int union_set_length;
if (!union_set)
union_set = new char [2 * get_max_keysig_size ()];
if (option[DEBUG])
{
fprintf (stderr, "collision on keyword #%d, prior = \"%.*s\", curr = \"%.*s\" hash = %d\n",
_num_done,
prior->_allchars_length, prior->_allchars,
curr->_allchars_length, curr->_allchars,
curr->_hash_value);
fflush (stderr);
}
union_set_length = compute_disjoint_union (prior->_selchars, prior->_selchars_length, curr->_selchars, curr->_selchars_length, union_set);
sort_set (union_set, union_set_length);
/* Try changing some values, if change doesn't alter other values continue normal action. */
_fewest_collisions++;
const char *p = union_set;
int i = union_set_length;
for (; i > 0; p++, i--)
if (!affects_prev (*p, curr))
{
if (option[DEBUG])
{
fprintf (stderr, " by changing asso_value['%c'] (char #%d) to %d\n",
*p, p - union_set + 1, _asso_values[static_cast<unsigned char>(*p)]);
fflush (stderr);
}
return; /* Good, doesn't affect previous hash values, we'll take it. */
}
for (KeywordExt_List *ptr = _head; ; ptr = ptr->rest())
{
KeywordExt* keyword = ptr->first();
if (keyword == curr)
break;
hash (keyword);
}
hash (curr);
if (option[DEBUG])
{
fprintf (stderr, "** collision not resolved after %d iterations, %d duplicates remain, continuing...\n",
!option[FAST] ? get_asso_max () : option.get_iterations () ? option.get_iterations () : keyword_list_length (),
_fewest_collisions + _total_duplicates);
fflush (stderr);
}
}
/* Does the hard stuff....
Initializes the Iteration Number array, and attempts to find a perfect
function that will hash all the key words without getting any
duplications. This is made much easier since we aren't attempting
to generate *minimum* functions, only perfect ones.
If we can't generate a perfect function in one pass *and* the user
hasn't enabled the DUP option, we'll inform the user to try the
randomization option, use -D, or choose alternative key positions.
The alternatives (e.g., back-tracking) are too time-consuming, i.e,
exponential in the number of keys. */
int
Gen_Perf::doit_all ()
{
KeywordExt_List *curr;
for (curr = _head; curr != NULL; curr = curr->rest())
{
KeywordExt *currkw = curr->first();
hash (currkw);
for (KeywordExt_List *ptr = _head; ptr != curr; ptr = ptr->rest())
{
KeywordExt *ptrkw = ptr->first();
if (ptrkw->_hash_value == currkw->_hash_value)
{
change (ptrkw, currkw);
break;
}
}
_num_done++;
}
/* Make one final check, just to make sure nothing weird happened.... */
_collision_detector->clear ();
for (curr = _head; curr; curr = curr->rest())
{
unsigned int hashcode = hash (curr->first());
if (_collision_detector->set_bit (hashcode))
{
if (option[DUP]) /* Keep track of this number... */
_total_duplicates++;
else /* Yow, big problems. we're outta here! */
{
fprintf (stderr,
"\nInternal error, duplicate value %d:\n"
"try options -D or -r, or use new key positions.\n\n",
hashcode);
return 1;
}
}
}
/* Sorts the key word list by hash value, and then outputs the list.
The generated hash table code is only output if the early stage of
processing turned out O.K. */
sort ();
Output outputter (_head, _array_type, _return_type, _struct_tag, _additional_code,
_include_src, _total_keys, _total_duplicates, _max_key_len,
_min_key_len, this);
outputter.output ();
return 0;
}
/* Prints out some diagnostics upon completion. */
Gen_Perf::~Gen_Perf ()
{
if (option[DEBUG])
{
fprintf (stderr, "\ndumping occurrence and associated values tables\n");
for (int i = 0; i < ALPHA_SIZE; i++)
if (_occurrences[i])
fprintf (stderr, "asso_values[%c] = %6d, occurrences[%c] = %6d\n",
i, _asso_values[i], i, _occurrences[i]);
fprintf (stderr, "end table dumping\n");
}
delete _collision_detector;
}

53
src/gen-perf.h
View File

@@ -1,53 +0,0 @@
/* This may look like C code, but it is really -*- C++ -*- */
/* Provides high-level routines to manipulate the keyword list
structures the code generation output.
Copyright (C) 1989-1998, 2000, 2002 Free Software Foundation, Inc.
Written by Douglas C. Schmidt <schmidt@ics.uci.edu>
and Bruno Haible <bruno@clisp.org>.
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 2, 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 this program; see the file COPYING.
If not, write to the Free Software Foundation, Inc.,
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#ifndef gen_perf_h
#define gen_perf_h 1
#include "key-list.h"
#include "bool-array.h"
class Gen_Perf : private Key_List
{
private:
int _max_hash_value; /* Maximum possible hash value. */
int _fewest_collisions; /* Records fewest # of collisions for asso value. */
int _num_done; /* Number of keywords processed without a collision. */
Bool_Array * _collision_detector;
void change (KeywordExt *prior, KeywordExt *curr);
bool affects_prev (char c, KeywordExt *curr);
static int hash (KeywordExt *key_node);
static int compute_disjoint_union (const char *set_1, int size_1, const char *set_2, int size_2, char *set_3);
static void sort_set (char *union_set, int len);
public:
Gen_Perf ();
~Gen_Perf ();
int doit_all ();
};
#endif

4
src/input.cc
View File

@@ -152,6 +152,9 @@ Input::strcspn (const char *s, const char *reject)
void void
Input::set_output_types () Input::set_output_types ()
{ {
_array_type = NULL;
_return_type = NULL;
_struct_tag = NULL;
if (option[TYPE]) if (option[TYPE])
{ {
_array_type = get_array_type (); _array_type = get_array_type ();
@@ -348,6 +351,7 @@ Input::read_keys ()
temp->rest() = parse_line (ptr, delimiter); temp->rest() = parse_line (ptr, delimiter);
/* See if any additional C code is included at end of this file. */ /* See if any additional C code is included at end of this file. */
_additional_code = false;
if (ptr) if (ptr)
_additional_code = true; _additional_code = true;
} }

380
src/key-list.cc
View File

@@ -1,380 +0,0 @@
/* Routines for building, ordering, and printing the keyword list.
Copyright (C) 1989-1998, 2000, 2002 Free Software Foundation, Inc.
Written by Douglas C. Schmidt <schmidt@ics.uci.edu>
and Bruno Haible <bruno@clisp.org>.
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 2, 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 this program; see the file COPYING.
If not, write to the Free Software Foundation, Inc.,
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#include <stdio.h>
#include <stdlib.h> /* declares exit() */
#include <limits.h> /* defines INT_MIN, INT_MAX */
#include "options.h"
#include "key-list.h"
#include "input.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)))
bool Key_List::_determined[MAX_ALPHA_SIZE];
/* Destructor dumps diagnostics during debugging. */
Key_List::~Key_List ()
{
if (option[DEBUG])
{
fprintf (stderr, "\nDumping key list information:\ntotal non-static linked keywords = %d"
"\ntotal keywords = %d\ntotal duplicates = %d\nmaximum key length = %d\n",
_list_len, _total_keys, _total_duplicates, _max_key_len);
dump ();
fprintf (stderr, "End dumping list.\n\n");
}
}
class KeywordExt_Factory : public Keyword_Factory
{
virtual Keyword * create_keyword (const char *allchars, int allchars_length,
const char *rest);
};
Keyword *
KeywordExt_Factory::create_keyword (const char *allchars, int allchars_length, const char *rest)
{
return new KeywordExt (allchars, allchars_length, rest);
}
/* Reads in all keys from standard input and creates a linked list pointed
to by _head. This list is then quickly checked for "links", i.e.,
unhashable elements possessing identical key sets and lengths. */
void
Key_List::read_keys ()
{
KeywordExt_Factory factory;
Input inputter (&factory);
inputter.read_keys ();
_array_type = inputter._array_type;
_return_type = inputter._return_type;
_struct_tag = inputter._struct_tag;
_include_src = inputter._include_src;
_additional_code = inputter._additional_code;
_head = static_cast<KeywordExt_List*>(inputter._head);
KeywordExt_List *temp;
KeywordExt_List *trail = NULL;
for (temp = _head; temp; temp = temp->rest())
{
temp->first()->init_selchars(this);
_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]);
/* Test whether there are any links and also set the maximum length of
an identifier in the keyword list. */
for (temp = _head; temp; temp = temp->rest())
{
KeywordExt *keyword = temp->first();
KeywordExt *other_keyword = found_link.insert (keyword);
/* 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. */
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();
/* 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
trail = temp;
/* 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;
}
delete[] table;
/* Exit program if links exists and option[DUP] not set, since we can't continue */
if (_total_duplicates)
{
if (option[DUP])
fprintf (stderr, "%d input keys have identical hash values, examine output carefully...\n",
_total_duplicates);
else
{
fprintf (stderr, "%d input keys have identical hash values,\ntry different key positions or use option -D.\n",
_total_duplicates);
exit (1);
}
}
/* Exit program if an empty string is used as key, since the comparison
expressions don't work correctly for looking up an empty string. */
if (_min_key_len == 0)
{
fprintf (stderr, "Empty input key is not allowed.\nTo recognize an empty input key, your code should check for\nlen == 0 before calling the gperf generated lookup function.\n");
exit (1);
}
}
/* Recursively merges two sorted lists together to form one sorted list. The
ordering criteria is by frequency of occurrence of elements in the key set
or by the hash value. This is a kludge, but permits nice sharing of
almost identical code without incurring the overhead of a function
call comparison. */
KeywordExt_List *
Key_List::merge (KeywordExt_List *list1, KeywordExt_List *list2)
{
KeywordExt_List *result;
KeywordExt_List **resultp = &result;
for (;;)
{
if (!list1)
{
*resultp = list2;
break;
}
if (!list2)
{
*resultp = list1;
break;
}
if (_occurrence_sort && list1->first()->_occurrence < list2->first()->_occurrence
|| _hash_sort && list1->first()->_hash_value > list2->first()->_hash_value)
{
*resultp = list2;
resultp = &list2->rest(); list2 = list1; list1 = *resultp;
}
else
{
*resultp = list1;
resultp = &list1->rest(); list1 = *resultp;
}
}
return result;
}
/* Applies the merge sort algorithm to recursively sort the key list by
frequency of occurrence of elements in the key set. */
KeywordExt_List *
Key_List::merge_sort (KeywordExt_List *head)
{
if (!head || !head->rest())
return head;
else
{
KeywordExt_List *middle = head;
KeywordExt_List *temp = head->rest()->rest();
while (temp)
{
temp = temp->rest();
middle = middle->rest();
if (temp)
temp = temp->rest();
}
temp = middle->rest();
middle->rest() = 0;
return merge (merge_sort (head), merge_sort (temp));
}
}
/* Returns the frequency of occurrence of elements in the key set. */
inline int
Key_List::get_occurrence (KeywordExt *ptr)
{
int value = 0;
const char *p = ptr->_selchars;
unsigned int i = ptr->_selchars_length;
for (; i > 0; p++, i--)
value += _occurrences[static_cast<unsigned char>(*p)];
return value;
}
/* Enables the index location of all key set elements that are now
determined. */
inline void
Key_List::set_determined (KeywordExt *ptr)
{
const char *p = ptr->_selchars;
unsigned int i = ptr->_selchars_length;
for (; i > 0; p++, i--)
_determined[static_cast<unsigned char>(*p)] = true;
}
/* Returns TRUE if PTR's key set is already completely determined. */
inline bool
Key_List::already_determined (KeywordExt *ptr)
{
bool is_determined = true;
const char *p = ptr->_selchars;
unsigned int i = ptr->_selchars_length;
for (; is_determined && i > 0; p++, i--)
is_determined = _determined[static_cast<unsigned char>(*p)];
return is_determined;
}
/* Reorders the table by first sorting the list so that frequently occuring
keys appear first, and then the list is reordered so that keys whose values
are already determined will be placed towards the front of the list. This
helps prune the search time by handling inevitable collisions early in the
search process. See Cichelli's paper from Jan 1980 JACM for details.... */
void
Key_List::reorder ()
{
KeywordExt_List *ptr;
for (ptr = _head; ptr; ptr = ptr->rest())
{
KeywordExt *keyword = ptr->first();
keyword->_occurrence = get_occurrence (keyword);
}
_hash_sort = false;
_occurrence_sort = true;
_head = merge_sort (_head);
for (ptr = _head; ptr->rest(); ptr = ptr->rest())
{
set_determined (ptr->first());
if (!already_determined (ptr->rest()->first()))
{
KeywordExt_List *trail_ptr = ptr->rest();
KeywordExt_List *run_ptr = trail_ptr->rest();
for (; run_ptr; run_ptr = trail_ptr->rest())
{
if (already_determined (run_ptr->first()))
{
trail_ptr->rest() = run_ptr->rest();
run_ptr->rest() = ptr->rest();
ptr = ptr->rest() = run_ptr;
}
else
trail_ptr = run_ptr;
}
}
}
}
/* Sorts the keys by hash value. */
void
Key_List::sort ()
{
_hash_sort = true;
_occurrence_sort = false;
_head = merge_sort (_head);
}
/* Dumps the key list to stderr stream. */
void
Key_List::dump ()
{
int field_width = get_max_keysig_size ();
fprintf (stderr, "\nList contents are:\n(hash value, key length, index, %*s, keyword):\n",
field_width, "selchars");
for (KeywordExt_List *ptr = _head; ptr; ptr = ptr->rest())
fprintf (stderr, "%11d,%11d,%6d, %*.*s, %.*s\n",
ptr->first()->_hash_value, ptr->first()->_allchars_length, ptr->first()->_final_index,
field_width, ptr->first()->_selchars_length, ptr->first()->_selchars,
ptr->first()->_allchars_length, ptr->first()->_allchars);
}
/* Simple-minded constructor action here... */
Key_List::Key_List ()
{
_total_keys = 0;
_max_key_len = INT_MIN;
_min_key_len = INT_MAX;
_array_type = 0;
_return_type = 0;
_struct_tag = 0;
_head = 0;
_total_duplicates = 0;
_additional_code = false;
}
/* Returns the length of entire key list. */
int
Key_List::keyword_list_length ()
{
return _list_len;
}
/* Returns length of longest key read. */
int
Key_List::max_key_length ()
{
return _max_key_len;
}
/* Returns number of key positions. */
int
Key_List::get_max_keysig_size ()
{
return option[ALLCHARS] ? _max_key_len : option.get_max_keysig_size ();
}

8
src/keyword.cc
View File

@@ -60,8 +60,8 @@ static inline void sort_char_set (char *base, int len)
} }
} }
/* Initialize selchars and selchars_length, and update v->occurrences. */ /* Initialize selchars and selchars_length, and update occurrences. */
void KeywordExt::init_selchars (Vectors *v) void KeywordExt::init_selchars (int *occurrences)
{ {
const char *k = _allchars; const char *k = _allchars;
char *key_set = char *key_set =
@@ -71,7 +71,7 @@ void KeywordExt::init_selchars (Vectors *v)
if (option[ALLCHARS]) if (option[ALLCHARS])
/* Use all the character positions in the KEY. */ /* Use all the character positions in the KEY. */
for (int i = _allchars_length; i > 0; k++, ptr++, i--) for (int i = _allchars_length; i > 0; k++, ptr++, i--)
v->_occurrences[static_cast<unsigned char>(*ptr = *k)]++; occurrences[static_cast<unsigned char>(*ptr = *k)]++;
else else
/* Only use those character positions specified by the user. */ /* Only use those character positions specified by the user. */
{ {
@@ -90,7 +90,7 @@ void KeywordExt::init_selchars (Vectors *v)
else else
/* Out of range of KEY length, so we'll just skip it. */ /* Out of range of KEY length, so we'll just skip it. */
continue; continue;
v->_occurrences[static_cast<unsigned char>(*ptr)]++; occurrences[static_cast<unsigned char>(*ptr)]++;
ptr++; ptr++;
} }

4
src/keyword.h
View File

@@ -57,8 +57,8 @@ struct KeywordExt : public Keyword
KeywordExt * _duplicate_link; KeywordExt * _duplicate_link;
/* Methods depending on the keyposition list. */ /* Methods depending on the keyposition list. */
/* Initialize selchars and selchars_length, and update v->occurrences. */ /* Initialize selchars and selchars_length, and update occurrences. */
void init_selchars (Vectors *v); void init_selchars (int *occurrences);
/* Data members used by the algorithm. */ /* Data members used by the algorithm. */
int _occurrence; /* A metric for frequency of key set occurrences. */ int _occurrence; /* A metric for frequency of key set occurrences. */

57
src/main.cc
View File

@@ -1,4 +1,4 @@
/* Driver program for the Gen_Perf hash function generator /* Driver program for the hash function generator
Copyright (C) 1989-1998, 2000, 2002 Free Software Foundation, Inc. Copyright (C) 1989-1998, 2000, 2002 Free Software Foundation, Inc.
Written by Douglas C. Schmidt <schmidt@ics.uci.edu> Written by Douglas C. Schmidt <schmidt@ics.uci.edu>
and Bruno Haible <bruno@clisp.org>. and Bruno Haible <bruno@clisp.org>.
@@ -20,26 +20,63 @@
If not, write to the Free Software Foundation, Inc., If not, write to the Free Software Foundation, Inc.,
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
/* Simple driver program for the Gen_Perf.hash function generator.
Most of the hard work is done in class Gen_Perf and its class methods. */
#include <stdio.h> #include <stdio.h>
#include "options.h" #include "options.h"
#include "gen-perf.h" #include "input.h"
#include "search.h"
#include "output.h"
/* This Keyword factory produces KeywordExt instances. */
class KeywordExt_Factory : public Keyword_Factory
{
virtual Keyword * create_keyword (const char *allchars, int allchars_length,
const char *rest);
};
Keyword *
KeywordExt_Factory::create_keyword (const char *allchars, int allchars_length, const char *rest)
{
return new KeywordExt (allchars, allchars_length, rest);
}
int int
main (int argc, char *argv[]) main (int argc, char *argv[])
{ {
/* Sets the Options. */ /* Set the Options. */
option.parse_options (argc, argv); option.parse_options (argc, argv);
/* Initializes the key word list. */ /* Initialize the key word list. */
Gen_Perf generate_table; KeywordExt_Factory factory;
Input inputter (&factory);
Vectors::ALPHA_SIZE = (option[SEVENBIT] ? 128 : 256);
inputter.read_keys ();
/* We can cast the keyword list to KeywordExt_List* because its list
elements were created by KeywordExt_Factory. */
KeywordExt_List* list = static_cast<KeywordExt_List*>(inputter._head);
/* Generates and prints the Gen_Perf hash table. */ /* Search for a good hash function. */
int status = generate_table.doit_all (); Search searcher (list);
searcher.optimize ();
/* Output the hash function code. */
Output outputter (searcher._head,
inputter._array_type,
inputter._return_type,
inputter._struct_tag,
inputter._additional_code,
inputter._include_src,
searcher._total_keys,
searcher._total_duplicates,
searcher._max_key_len,
searcher._min_key_len,
&searcher);
outputter.output ();
/* Check for write error on stdout. */ /* Check for write error on stdout. */
int status = 0;
if (fflush (stdout) || ferror (stdout)) if (fflush (stdout) || ferror (stdout))
status = 1; status = 1;

628
src/search.cc Normal file
View File

@@ -0,0 +1,628 @@
/* Search algorithm.
Copyright (C) 1989-1998, 2000, 2002 Free Software Foundation, Inc.
Written by Douglas C. Schmidt <schmidt@ics.uci.edu>
and Bruno Haible <bruno@clisp.org>.
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 2, 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 this program; see the file COPYING.
If not, write to the Free Software Foundation, Inc.,
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#include <stdio.h>
#include <stdlib.h> /* declares exit(), rand(), srand() */
#include <string.h> /* declares memset(), memcmp() */
#include <time.h> /* declares time() */
#include <limits.h> /* defines INT_MIN, INT_MAX */
#include "options.h"
#include "hash-table.h"
#include "search.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)))
Search::Search (KeywordExt_List *list)
: _head (list)
{
}
bool Search::_determined[MAX_ALPHA_SIZE];
void
Search::prepare ()
{
KeywordExt_List *temp;
KeywordExt_List *trail = NULL;
_total_keys = 0;
for (temp = _head; temp; temp = temp->rest())
{
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]);
/* 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);
/* 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. */
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();
/* 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
trail = temp;
/* 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;
}
delete[] table;
/* Exit program if links exists and option[DUP] not set, since we can't continue */
if (_total_duplicates)
{
if (option[DUP])
fprintf (stderr, "%d input keys have identical hash values, examine output carefully...\n",
_total_duplicates);
else
{
fprintf (stderr, "%d input keys have identical hash values,\ntry different key positions or use option -D.\n",
_total_duplicates);
exit (1);
}
}
/* Exit program if an empty string is used as key, since the comparison
expressions don't work correctly for looking up an empty string. */
if (_min_key_len == 0)
{
fprintf (stderr, "Empty input key is not allowed.\nTo recognize an empty input key, your code should check for\nlen == 0 before calling the gperf generated lookup function.\n");
exit (1);
}
}
/* Recursively merges two sorted lists together to form one sorted list. The
ordering criteria is by frequency of occurrence of elements in the key set
or by the hash value. This is a kludge, but permits nice sharing of
almost identical code without incurring the overhead of a function
call comparison. */
KeywordExt_List *
Search::merge (KeywordExt_List *list1, KeywordExt_List *list2)
{
KeywordExt_List *result;
KeywordExt_List **resultp = &result;
for (;;)
{
if (!list1)
{
*resultp = list2;
break;
}
if (!list2)
{
*resultp = list1;
break;
}
if (_occurrence_sort && list1->first()->_occurrence < list2->first()->_occurrence
|| _hash_sort && list1->first()->_hash_value > list2->first()->_hash_value)
{
*resultp = list2;
resultp = &list2->rest(); list2 = list1; list1 = *resultp;
}
else
{
*resultp = list1;
resultp = &list1->rest(); list1 = *resultp;
}
}
return result;
}
/* Applies the merge sort algorithm to recursively sort the key list by
frequency of occurrence of elements in the key set. */
KeywordExt_List *
Search::merge_sort (KeywordExt_List *head)
{
if (!head || !head->rest())
return head;
else
{
KeywordExt_List *middle = head;
KeywordExt_List *temp = head->rest()->rest();
while (temp)
{
temp = temp->rest();
middle = middle->rest();
if (temp)
temp = temp->rest();
}
temp = middle->rest();
middle->rest() = 0;
return merge (merge_sort (head), merge_sort (temp));
}
}
/* Returns the frequency of occurrence of elements in the key set. */
inline int
Search::get_occurrence (KeywordExt *ptr)
{
int value = 0;
const char *p = ptr->_selchars;
unsigned int i = ptr->_selchars_length;
for (; i > 0; p++, i--)
value += _occurrences[static_cast<unsigned char>(*p)];
return value;
}
/* Enables the index location of all key set elements that are now
determined. */
inline void
Search::set_determined (KeywordExt *ptr)
{
const char *p = ptr->_selchars;
unsigned int i = ptr->_selchars_length;
for (; i > 0; p++, i--)
_determined[static_cast<unsigned char>(*p)] = true;
}
/* Returns TRUE if PTR's key set is already completely determined. */
inline bool
Search::already_determined (KeywordExt *ptr)
{
bool is_determined = true;
const char *p = ptr->_selchars;
unsigned int i = ptr->_selchars_length;
for (; is_determined && i > 0; p++, i--)
is_determined = _determined[static_cast<unsigned char>(*p)];
return is_determined;
}
/* Reorders the table by first sorting the list so that frequently occuring
keys appear first, and then the list is reordered so that keys whose values
are already determined will be placed towards the front of the list. This
helps prune the search time by handling inevitable collisions early in the
search process. See Cichelli's paper from Jan 1980 JACM for details.... */
void
Search::reorder ()
{
KeywordExt_List *ptr;
for (ptr = _head; ptr; ptr = ptr->rest())
{
KeywordExt *keyword = ptr->first();
keyword->_occurrence = get_occurrence (keyword);
}
_hash_sort = false;
_occurrence_sort = true;
_head = merge_sort (_head);
for (ptr = _head; ptr->rest(); ptr = ptr->rest())
{
set_determined (ptr->first());
if (!already_determined (ptr->rest()->first()))
{
KeywordExt_List *trail_ptr = ptr->rest();
KeywordExt_List *run_ptr = trail_ptr->rest();
for (; run_ptr; run_ptr = trail_ptr->rest())
{
if (already_determined (run_ptr->first()))
{
trail_ptr->rest() = run_ptr->rest();
run_ptr->rest() = ptr->rest();
ptr = ptr->rest() = run_ptr;
}
else
trail_ptr = run_ptr;
}
}
}
}
/* Returns the length of entire key list. */
int
Search::keyword_list_length ()
{
return _list_len;
}
/* Returns length of longest key read. */
int
Search::max_key_length ()
{
return _max_key_len;
}
/* Returns number of key positions. */
int
Search::get_max_keysig_size ()
{
return option[ALLCHARS] ? _max_key_len : option.get_max_keysig_size ();
}
/* Generate a key set's hash value. */
inline int
Search::hash (KeywordExt *key_node)
{
int sum = option[NOLENGTH] ? 0 : key_node->_allchars_length;
const char *p = key_node->_selchars;
int i = key_node->_selchars_length;
for (; i > 0; p++, i--)
sum += _asso_values[static_cast<unsigned char>(*p)];
return key_node->_hash_value = sum;
}
/* Merge two disjoint hash key multisets to form the ordered disjoint union of the sets.
(In a multiset, an element can occur multiple times.)
Precondition: both set_1 and set_2 must be ordered. Returns the length
of the combined set. */
inline int
Search::compute_disjoint_union (const char *set_1, int size_1, const char *set_2, int size_2, char *set_3)
{
char *base = set_3;
while (size_1 > 0 && size_2 > 0)
if (*set_1 == *set_2)
set_1++, size_1--, set_2++, size_2--;
else
{
char next;
if (*set_1 < *set_2)
next = *set_1++, size_1--;
else
next = *set_2++, size_2--;
if (set_3 == base || next != set_3[-1])
*set_3++ = next;
}
while (size_1 > 0)
{
char next;
next = *set_1++, size_1--;
if (set_3 == base || next != set_3[-1])
*set_3++ = next;
}
while (size_2 > 0)
{
char next;
next = *set_2++, size_2--;
if (set_3 == base || next != set_3[-1])
*set_3++ = next;
}
return set_3 - base;
}
/* Sort the UNION_SET in increasing frequency of occurrence.
This speeds up later processing since we may assume the resulting
set (Set_3, in this case), is ordered. Uses insertion sort, since
the UNION_SET is typically short. */
inline void
Search::sort_set (char *union_set, int len)
{
int i, j;
for (i = 0, j = len - 1; i < j; i++)
{
int curr;
char tmp;
for (curr = i + 1, tmp = union_set[curr];
curr > 0 && _occurrences[static_cast<unsigned char>(tmp)] < _occurrences[static_cast<unsigned char>(union_set[curr-1])];
curr--)
union_set[curr] = union_set[curr - 1];
union_set[curr] = tmp;
}
}
/* Find out how character value change affects successfully hashed items.
Returns FALSE if no other hash values are affected, else returns TRUE.
Note that because Option.Get_Asso_Max is a power of two we can guarantee
that all legal Asso_Values are visited without repetition since
Option.Get_Jump was forced to be an odd value! */
inline bool
Search::affects_prev (char c, KeywordExt *curr)
{
int original_char = _asso_values[static_cast<unsigned char>(c)];
int total_iterations = !option[FAST]
? get_asso_max () : option.get_iterations () ? option.get_iterations () : keyword_list_length ();
/* Try all legal associated values. */
for (int i = total_iterations - 1; i >= 0; i--)
{
int collisions = 0;
_asso_values[static_cast<unsigned char>(c)] =
(_asso_values[static_cast<unsigned char>(c)] + (option.get_jump () ? option.get_jump () : rand ()))
& (get_asso_max () - 1);
/* Iteration Number array is a win, O(1) intialization time! */
_collision_detector->clear ();
/* See how this asso_value change affects previous keywords. If
it does better than before we'll take it! */
for (KeywordExt_List *ptr = _head; ; ptr = ptr->rest())
{
KeywordExt *keyword = ptr->first();
if (_collision_detector->set_bit (hash (keyword))
&& ++collisions >= _fewest_collisions)
break;
if (keyword == curr)
{
_fewest_collisions = collisions;
if (option[DEBUG])
fprintf (stderr, "- resolved after %d iterations", total_iterations - i);
return false;
}
}
}
/* Restore original values, no more tries. */
_asso_values[static_cast<unsigned char>(c)] = original_char;
/* If we're this far it's time to try the next character.... */
return true;
}
/* Change a character value, try least-used characters first. */
void
Search::change (KeywordExt *prior, KeywordExt *curr)
{
static char *union_set;
int union_set_length;
if (!union_set)
union_set = new char [2 * get_max_keysig_size ()];
if (option[DEBUG])
{
fprintf (stderr, "collision on keyword #%d, prior = \"%.*s\", curr = \"%.*s\" hash = %d\n",
_num_done,
prior->_allchars_length, prior->_allchars,
curr->_allchars_length, curr->_allchars,
curr->_hash_value);
fflush (stderr);
}
union_set_length = compute_disjoint_union (prior->_selchars, prior->_selchars_length, curr->_selchars, curr->_selchars_length, union_set);
sort_set (union_set, union_set_length);
/* Try changing some values, if change doesn't alter other values continue normal action. */
_fewest_collisions++;
const char *p = union_set;
int i = union_set_length;
for (; i > 0; p++, i--)
if (!affects_prev (*p, curr))
{
if (option[DEBUG])
{
fprintf (stderr, " by changing asso_value['%c'] (char #%d) to %d\n",
*p, p - union_set + 1, _asso_values[static_cast<unsigned char>(*p)]);
fflush (stderr);
}
return; /* Good, doesn't affect previous hash values, we'll take it. */
}
for (KeywordExt_List *ptr = _head; ; ptr = ptr->rest())
{
KeywordExt* keyword = ptr->first();
if (keyword == curr)
break;
hash (keyword);
}
hash (curr);
if (option[DEBUG])
{
fprintf (stderr, "** collision not resolved after %d iterations, %d duplicates remain, continuing...\n",
!option[FAST] ? get_asso_max () : option.get_iterations () ? option.get_iterations () : keyword_list_length (),
_fewest_collisions + _total_duplicates);
fflush (stderr);
}
}
/* Sorts the keys by hash value. */
void
Search::sort ()
{
_hash_sort = true;
_occurrence_sort = false;
_head = merge_sort (_head);
}
void
Search::optimize ()
{
prepare ();
if (option[ORDER])
reorder ();
_num_done = 1;
_fewest_collisions = 0;
int asso_value_max = option.get_size_multiple ();
int non_linked_length = keyword_list_length ();
if (asso_value_max == 0)
asso_value_max = non_linked_length;
else if (asso_value_max > 0)
asso_value_max *= non_linked_length;
else /* if (asso_value_max < 0) */
asso_value_max = non_linked_length / -asso_value_max;
set_asso_max (POW (asso_value_max));
if (option[RANDOM])
{
srand (reinterpret_cast<long>(time (0)));
for (int i = 0; i < ALPHA_SIZE; i++)
_asso_values[i] = (rand () & asso_value_max - 1);
}
else
{
int asso_value = option.get_initial_asso_value ();
if (asso_value) /* Initialize array if user requests non-zero default. */
for (int i = ALPHA_SIZE - 1; i >= 0; i--)
_asso_values[i] = asso_value & get_asso_max () - 1;
}
_max_hash_value = max_key_length () + get_asso_max () * get_max_keysig_size ();
_collision_detector = new Bool_Array (_max_hash_value + 1);
if (option[DEBUG])
fprintf (stderr, "total non-linked keys = %d\nmaximum associated value is %d"
"\nmaximum size of generated hash table is %d\n",
non_linked_length, asso_value_max, _max_hash_value);
KeywordExt_List *curr;
for (curr = _head; curr != NULL; curr = curr->rest())
{
KeywordExt *currkw = curr->first();
hash (currkw);
for (KeywordExt_List *ptr = _head; ptr != curr; ptr = ptr->rest())
{
KeywordExt *ptrkw = ptr->first();
if (ptrkw->_hash_value == currkw->_hash_value)
{
change (ptrkw, currkw);
break;
}
}
_num_done++;
}
/* Make one final check, just to make sure nothing weird happened.... */
_collision_detector->clear ();
for (curr = _head; curr; curr = curr->rest())
{
unsigned int hashcode = hash (curr->first());
if (_collision_detector->set_bit (hashcode))
{
if (option[DUP]) /* Keep track of this number... */
_total_duplicates++;
else /* Yow, big problems. we're outta here! */
{
fprintf (stderr,
"\nInternal error, duplicate value %d:\n"
"try options -D or -r, or use new key positions.\n\n",
hashcode);
exit (1);
}
}
}
/* Sorts the key word list by hash value. */
sort ();
}
/* Prints out some diagnostics upon completion. */
Search::~Search ()
{
delete _collision_detector;
if (option[DEBUG])
{
fprintf (stderr, "\ndumping occurrence and associated values tables\n");
for (int i = 0; i < ALPHA_SIZE; i++)
if (_occurrences[i])
fprintf (stderr, "asso_values[%c] = %6d, occurrences[%c] = %6d\n",
i, _asso_values[i], i, _occurrences[i]);
fprintf (stderr, "end table dumping\n");
fprintf (stderr, "\nDumping key list information:\ntotal non-static linked keywords = %d"
"\ntotal keywords = %d\ntotal duplicates = %d\nmaximum key length = %d\n",
_list_len, _total_keys, _total_duplicates, _max_key_len);
int field_width = get_max_keysig_size ();
fprintf (stderr, "\nList contents are:\n(hash value, key length, index, %*s, keyword):\n",
field_width, "selchars");
for (KeywordExt_List *ptr = _head; ptr; ptr = ptr->rest())
fprintf (stderr, "%11d,%11d,%6d, %*.*s, %.*s\n",
ptr->first()->_hash_value, ptr->first()->_allchars_length, ptr->first()->_final_index,
field_width, ptr->first()->_selchars_length, ptr->first()->_selchars,
ptr->first()->_allchars_length, ptr->first()->_allchars);
fprintf (stderr, "End dumping list.\n\n");
}
}

81
src/key-list.h → src/search.h
View File

@@ -1,8 +1,8 @@
/* This may look like C code, but it is really -*- C++ -*- */ /* This may look like C code, but it is really -*- C++ -*- */
/* Data and function member declarations for the keyword list class. /* Search algorithm.
Copyright (C) 1989-1998, 2002 Free Software Foundation, Inc. Copyright (C) 1989-1998, 2000, 2002 Free Software Foundation, Inc.
Written by Douglas C. Schmidt <schmidt@ics.uci.edu> Written by Douglas C. Schmidt <schmidt@ics.uci.edu>
and Bruno Haible <bruno@clisp.org>. and Bruno Haible <bruno@clisp.org>.
@@ -23,59 +23,52 @@
If not, write to the Free Software Foundation, Inc., If not, write to the Free Software Foundation, Inc.,
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
/* The key word list is a useful abstraction that keeps track of #ifndef search_h
various pieces of information that enable that fast generation #define search_h 1
of the Gen_Perf.hash function. A Key_List is a singly-linked
list of List_Nodes. */
#ifndef key_list_h
#define key_list_h 1
#include "keyword-list.h" #include "keyword-list.h"
#include "vectors.h" #include "vectors.h"
#include "read-line.h" #include "bool-array.h"
class Key_List : public Vectors class Search : public Vectors
{ {
protected: public:
const char * _array_type; /* Pointer to the type for word list. */ Search (KeywordExt_List *list);
const char * _return_type; /* Pointer to return type for lookup function. */ ~Search ();
const char * _struct_tag; /* Shorthand for user-defined struct tag type. */ void optimize ();
const char * _include_src; /* C source code to be included verbatim. */ private:
void prepare ();
KeywordExt_List * merge (KeywordExt_List *list1, KeywordExt_List *list2);
KeywordExt_List * merge_sort (KeywordExt_List *head);
static int get_occurrence (KeywordExt *ptr);
static void set_determined (KeywordExt *ptr);
static bool already_determined (KeywordExt *ptr);
void reorder ();
int keyword_list_length ();
int max_key_length ();
int get_max_keysig_size ();
static int hash (KeywordExt *key_node);
static int compute_disjoint_union (const char *set_1, int size_1, const char *set_2, int size_2, char *set_3);
static void sort_set (char *union_set, int len);
bool affects_prev (char c, KeywordExt *curr);
void change (KeywordExt *prior, KeywordExt *curr);
void sort ();
public:
KeywordExt_List * _head; /* Points to the head of the linked list. */
int _total_keys; /* Total number of keys, counting duplicates. */
int _total_duplicates; /* Total number of duplicate hash values. */
int _max_key_len; /* Maximum length of the longest keyword. */ int _max_key_len; /* Maximum length of the longest keyword. */
int _min_key_len; /* Minimum length of the shortest keyword. */ int _min_key_len; /* Minimum length of the shortest keyword. */
private: private:
int _list_len; /* Length of head's Key_List, not counting duplicates. */
bool _occurrence_sort; /* True if sorting by occurrence. */ bool _occurrence_sort; /* True if sorting by occurrence. */
bool _hash_sort; /* True if sorting by hash value. */ bool _hash_sort; /* True if sorting by hash value. */
protected:
bool _additional_code; /* True if any additional C code is included. */
private:
int _list_len; /* Length of head's Key_List, not counting duplicates. */
protected:
int _total_keys; /* Total number of keys, counting duplicates. */
int _size; /* Range of the hash table. */
private:
static bool _determined[MAX_ALPHA_SIZE]; /* Used in function reorder, below. */ static bool _determined[MAX_ALPHA_SIZE]; /* Used in function reorder, below. */
static int get_occurrence (KeywordExt *ptr); int _num_done; /* Number of keywords processed without a collision. */
static bool already_determined (KeywordExt *ptr); int _fewest_collisions; /* Records fewest # of collisions for asso value. */
static void set_determined (KeywordExt *ptr); int _max_hash_value; /* Maximum possible hash value. */
void dump (); Bool_Array * _collision_detector;
KeywordExt_List * merge (KeywordExt_List *list1, KeywordExt_List *list2); int _size; /* Range of the hash table. */
KeywordExt_List * merge_sort (KeywordExt_List *head);
protected:
KeywordExt_List * _head; /* Points to the head of the linked list. */
int _total_duplicates; /* Total number of duplicate hash values. */
public:
Key_List ();
~Key_List ();
int keyword_list_length ();
int max_key_length ();
void reorder ();
void sort ();
void read_keys ();
int get_max_keysig_size ();
void set_asso_max (int r) { _size = r; } void set_asso_max (int r) { _size = r; }
int get_asso_max () { return _size; } int get_asso_max () { return _size; }
}; };