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Rework Bool_Array.

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This commit is contained in:
Bruno Haible
2002-10-30 12:36:40 +00:00
parent c7f32d582f
commit a07f46bd1d
6 changed files with 59 additions and 66 deletions
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8
ChangeLog
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@@ -1,5 +1,13 @@
2002-10-03 Bruno Haible <bruno@clisp.org>
* src/bool-array.h (Bool_Array): Make all members non-static.
Add an argument to the constructor. Remove init(), rename reset() to
clear(), rename find() to set_bit().
* src/bool-array.icc: Move init() code into the constructor.
Rename reset() to clear(), rename find() to set_bit().
* src/gen-perf.h (Gen_Perf): Add collision_detector member.
* src/gen-perf.cc: Update.
* src/gen-perf.h (Gen_Perf::doit_all): Renamed from
Gen_Perf::operator ().
* src/gen-perf.cc (Gen_Perf::doit_all): Renamed from

8
src/bool-array.cc
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@@ -24,14 +24,10 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111, USA. */
#include <string.h>
#include "options.h"
unsigned int * Bool_Array::storage_array;
unsigned int Bool_Array::iteration_number;
unsigned int Bool_Array::size;
/* Prints out debugging diagnostics. */
/* Frees this object. */
Bool_Array::~Bool_Array (void)
{
/* Print out debugging diagnostics. */
if (option[DEBUG])
fprintf (stderr, "\ndumping boolean array information\n"
"size = %d\niteration number = %d\nend of array dump\n",

39
src/bool-array.h
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@@ -21,25 +21,38 @@ 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 02111-1307, USA. */
/* Define and implement a simple boolean array abstraction,
uses an Iteration Numbering implementation to save on initialization time. */
#ifndef bool_array_h
#define bool_array_h 1
/* A Bool_Array instance is a bit array of fixed size, optimized for being
filled sparsely and cleared frequently. For example, when processing
tests/chill.gperf, the array will be:
- of size 15391,
- clear will be called 3509 times,
- set_bit will be called 300394 times.
With a conventional bit array implementation, clear would be too slow.
With a tree/hash based bit array implementation, set_bit would be slower. */
class Bool_Array
{
private:
static unsigned int *storage_array; /* Initialization of the index space. */
static unsigned int iteration_number; /* Keep track of the current iteration. */
static unsigned int size; /* Keep track of array size. */
public:
Bool_Array (void);
~Bool_Array (void);
static void init (unsigned int *buffer, unsigned int s);
static int find (int hash_value);
static void reset (void);
/* Initializes the bit array with room for s bits, numbered from 0 to s-1. */
Bool_Array (unsigned int s);
/* Frees this object. */
~Bool_Array (void);
/* Resets all bits to zero. */
void clear (void);
/* Sets the specified bit to one. Returns its previous value (0 or 1). */
int set_bit (unsigned int index);
private:
unsigned int size; /* Size of array. */
unsigned int iteration_number; /* Number of times clear() was called + 1. */
/* For each index, we store in storage_array[index] the iteration_number at
the time set_bit(index) was last called. */
unsigned int *storage_array;
};
#ifdef __OPTIMIZE__ /* efficiency hack! */

37
src/bool-array.icc
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@@ -24,56 +24,47 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
//#include <string.h>
//#include "options.h"
/* Initializes the bit array with room for s bits, numbered from 0 to s-1. */
INLINE
Bool_Array::Bool_Array (void)
Bool_Array::Bool_Array (unsigned int s)
: size (s), iteration_number (1), storage_array (new unsigned int [s])
{
storage_array = 0;
iteration_number = size = 0;
}
INLINE void
Bool_Array::init (unsigned int *buffer, unsigned int s)
{
size = s;
iteration_number = 1;
storage_array = buffer;
memset (storage_array, 0, s * sizeof (*storage_array));
memset (storage_array, 0, s * sizeof (unsigned int));
if (option[DEBUG])
fprintf (stderr, "\nbool array size = %d, total bytes = %d\n",
size, (unsigned int) (size * sizeof (*storage_array)));
}
/* Sets the specified bit to one. Returns its previous value (0 or 1). */
INLINE int
Bool_Array::find (int index)
Bool_Array::set_bit (unsigned int index)
{
if (storage_array[index] == iteration_number)
/* The bit was set since the last clear() call. */
return 1;
else
{
/* The last operation on this bit was clear(). Set it now. */
storage_array[index] = iteration_number;
return 0;
}
}
/* Resets all bits to zero. */
INLINE void
Bool_Array::reset (void)
Bool_Array::clear (void)
{
/* If we wrap around it's time to zero things out again! However, this only
occurs once about every 2^31 or 2^15 iterations, so it should probably
never happen! */
occurs once about every 2^32 iterations, so it will not happen more
frequently than once per second. */
if (++iteration_number == 0)
{
if (option[DEBUG])
{
fprintf (stderr, "(re-initializing bool_array)...");
fflush (stderr);
}
iteration_number = 1;
memset (storage_array, 0, size * sizeof (*storage_array));
memset (storage_array, 0, size * sizeof (unsigned int));
if (option[DEBUG])
{
fprintf (stderr, "done\n");
fprintf (stderr, "(re-initialized bool_array)\n");
fflush (stderr);
}
}

28
src/gen-perf.cc
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@@ -71,6 +71,7 @@ Gen_Perf::Gen_Perf (void)
}
max_hash_value = Key_List::max_key_length () + option.get_asso_max () *
option.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"
@@ -183,13 +184,13 @@ Gen_Perf::affects_prev (char c, List_Node *curr)
& (option.get_asso_max () - 1);
/* Iteration Number array is a win, O(1) intialization time! */
reset ();
collision_detector->clear ();
/* See how this asso_value change affects previous keywords. If
it does better than before we'll take it! */
for (List_Node *ptr = head;
!Bool_Array::find (hash (ptr)) || ++collisions < fewest_collisions;
!collision_detector->set_bit (hash (ptr)) || ++collisions < fewest_collisions;
ptr = ptr->next)
if (ptr == curr)
{
@@ -274,18 +275,6 @@ Gen_Perf::change (List_Node *prior, List_Node *curr)
int
Gen_Perf::doit_all (void)
{
#if LARGE_STACK_ARRAYS
unsigned int buffer[max_hash_value + 1];
#else
// Note: we don't use new, because that invokes a custom operator new.
unsigned int *buffer
= (unsigned int*) malloc (sizeof(unsigned int) * (max_hash_value + 1));
if (buffer == NULL)
abort ();
#endif
Bool_Array::init (buffer, max_hash_value + 1);
List_Node *curr;
for (curr = head; curr; curr = curr->next)
{
@@ -302,19 +291,16 @@ Gen_Perf::doit_all (void)
/* Make one final check, just to make sure nothing weird happened.... */
Bool_Array::reset ();
collision_detector->clear ();
for (curr = head; curr; curr = curr->next)
if (Bool_Array::find (hash (curr)))
if (collision_detector->set_bit (hash (curr)))
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", hash (curr));
#if !LARGE_STACK_ARRAYS
free ((char *) buffer);
#endif
return 1;
}
@@ -324,9 +310,6 @@ Gen_Perf::doit_all (void)
sort ();
output ();
#if !LARGE_STACK_ARRAYS
free ((char *) buffer);
#endif
return 0;
}
@@ -346,5 +329,6 @@ Gen_Perf::~Gen_Perf (void)
fprintf (stderr, "end table dumping\n");
}
delete collision_detector;
}

5
src/gen-perf.h
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@@ -3,7 +3,7 @@
/* Provides high-level routines to manipulate the keyword list
structures the code generation output.
Copyright (C) 1989-1998, 2000 Free Software Foundation, Inc.
Copyright (C) 1989-1998, 2000, 2002 Free Software Foundation, Inc.
written by Douglas C. Schmidt (schmidt@ics.uci.edu)
This file is part of GNU GPERF.
@@ -28,12 +28,13 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111, USA. */
#include "key-list.h"
#include "bool-array.h"
class Gen_Perf : private Key_List, private Bool_Array
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 (List_Node *prior, List_Node *curr);
int affects_prev (char c, List_Node *curr);