/* PackTab - Pack a static table
* Copyright (C) 2001 Behdad Esfahbod.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library, in a file named COPYING; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307, USA
*
* For licensing issues, contact <fwpg@sharif.edu>.
*/
/*
8 <= N <= 2^21
int key
1 <= max_depth <= 21
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "packtab.h"
typedef signed int uni_table[1024 * 1024 * 2];
static int n, a, max_depth, digits, tab_width, per_row;
static long N;
signed int def_key;
static uni_table temp, x, perm, *tab;
static long pow[22], cluster, cmpcluster;
static const char *const *name, *key_type_name, *table_name, *macro_name;
static FILE *f;
static long
most_binary (
long min,
long max
)
{
/* min should be less than max */
register int i, ii;
if (min == max)
return max;
for (i = 21; max < pow[i]; i--)
;
ii = i;
while (i && !((min ^ max) & pow[i]))
i--;
if (ii == i)
{
/* min is less than half of max */
for (i = 21 - 1; min < pow[i]; i--)
;
i++;
return pow[i];
}
return max & (pow[i] - 1);
}
static void
init (
const signed int *table
)
{
register int i;
/* initialize powers of two */
pow[0] = 1;
for (i = 1; i <= 21; i++)
pow[i] = pow[i - 1] << 1;
/* reduce number of elements to get a more binary number */
{
long essen;
/* find number of essential items */
essen = N - 1;
while (essen && table[essen] == def_key)
essen--;
essen++;
N = most_binary (essen, N);
}
for (n = 21; N % pow[n]; n--)
;
digits = (n + 3) / 4;
for (i = 6; i; i--)
if (pow[i] * (tab_width + 1) < 80)
break;
per_row = pow[i];
}
static int
compare (
const void *r,
const void *s
)
{
int i;
for (i = 0; i < cmpcluster; i++)
if (((int *) r)[i] != ((int *) s)[i])
return ((int *) r)[i] - ((int *) s)[i];
return 0;
}
static int lev, best_lev, p[22], best_p[22], nn;
static long c[22], best_c[22], s, best_s;
static long t[22], best_t[22], clusters[22], best_cluster[22];
static void
found (
void
)
{
int i;
if (s < best_s)
{
best_s = s;
best_lev = lev;
for (i = 0; i <= lev; i++)
{
best_p[i] = p[i];
best_c[i] = c[i];
best_t[i] = t[i];
best_cluster[i] = clusters[i];
}
}
}
static void
bt (
int node_size
)
{
long i, j, k, y, sbak;
long key_bytes;
if (t[lev] == 1)
{
found ();
return;
}
if (lev == max_depth)
return;
for (i = 1 - t[lev] % 2; i <= nn + (t[lev] >> nn) % 2; i++)
{
nn -= (p[lev] = i);
clusters[lev] = cluster = (i && nn >= 0) ? pow[i] : t[lev];
cmpcluster = cluster + 1;
t[lev + 1] = (t[lev] - 1) / cluster + 1;
for (j = 0; j < t[lev + 1]; j++)
{
memmove (temp + j * cmpcluster, tab[lev] + j * cluster,
cluster * sizeof (tab[lev][0]));
temp[j * cmpcluster + cluster] = j;
}
qsort (temp, t[lev + 1], cmpcluster * sizeof (temp[0]), compare);
for (j = 0; j < t[lev + 1]; j++)
{
perm[j] = temp[j * cmpcluster + cluster];
temp[j * cmpcluster + cluster] = 0;
}
k = 1;
y = 0;
tab[lev + 1][perm[0]] = perm[0];
for (j = 1; j < t[lev + 1]; j++)
{
if (compare (temp + y, temp + y + cmpcluster))
{
k++;
tab[lev + 1][perm[j]] = perm[j];
}
else
tab[lev + 1][perm[j]] = tab[lev + 1][perm[j - 1]];
y += cmpcluster;
}
sbak = s;
s += k * node_size * cluster;
c[lev] = k;
if (s >= best_s)
{
s = sbak;
nn += i;
return;
}
key_bytes = k * cluster;
key_bytes = key_bytes < 0xff ? 1 : key_bytes < 0xffff ? 2 : 4;
lev++;
bt (key_bytes);
lev--;
s = sbak;
nn += i;
}
}
static void
solve (
void
)
{
best_lev = max_depth + 2;
best_s = N * a * 2;
lev = 0;
s = 0;
nn = n;
t[0] = N;
bt (a);
}
static void
write_array (
long max_key
)
{
int i, j, k, y, ii, ofs;
const char *key_type;
if (best_t[lev] == 1)
return;
nn -= (i = best_p[lev]);
cluster = best_cluster[lev];
cmpcluster = cluster + 1;
t[lev + 1] = best_t[lev + 1];
for (j = 0; j < t[lev + 1]; j++)
{
memmove (temp + j * cmpcluster, tab[lev] + j * cluster,
cluster * sizeof (tab[lev][0]));
temp[j * cmpcluster + cluster] = j;
}
qsort (temp, t[lev + 1], cmpcluster * sizeof (temp[0]), compare);
for (j = 0; j < t[lev + 1]; j++)
{
perm[j] = temp[j * cmpcluster + cluster];
temp[j * cmpcluster + cluster] = 0;
}
k = 1;
y = 0;
tab[lev + 1][perm[0]] = x[0] = perm[0];
for (j = 1; j < t[lev + 1]; j++)
{
if (compare (temp + y, temp + y + cmpcluster))
{
x[k] = perm[j];
tab[lev + 1][perm[j]] = x[k];
k++;
}
else
tab[lev + 1][perm[j]] = tab[lev + 1][perm[j - 1]];
y += cmpcluster;
}
i = 0;
for (ii = 1; ii < k; ii++)
if (x[ii] < x[i])
i = ii;
key_type = !lev ? key_type_name :
max_key <= 0xff ? "PACKTAB_UINT8" :
max_key <= 0xffff ? "PACKTAB_UINT16" : "PACKTAB_UINT32";
fprintf (f, "static const %s %sLev%d[%ld*%d] = {", key_type, table_name,
best_lev - lev - 1, cluster, k);
ofs = 0;
for (ii = 0; ii < k; ii++)
{
int kk, jj;
fprintf (f, "\n#define %sLev%d_%0*lX 0x%0X", table_name,
best_lev - lev - 1, digits, x[i] * pow[n - nn], ofs);
kk = x[i] * cluster;
if (!lev)
if (name)
for (j = 0; j < cluster; j++)
{
if (!(j % per_row) && j != cluster - 1)
fprintf (f, "\n ");
fprintf (f, "%*s,", tab_width, name[tab[lev][kk++]]);
}
else
for (j = 0; j < cluster; j++)
{
if (!(j % per_row) && j != cluster - 1)
fprintf (f, "\n ");
fprintf (f, "%*d,", tab_width, tab[lev][kk++]);
}
else
for (j = 0; j < cluster; j++, kk++)
fprintf (f, "\n %sLev%d_%0*lX, /* %0*lX..%0*lX */", table_name,
best_lev - lev, digits,
tab[lev][kk] * pow[n - nn - best_p[lev]], digits,
x[i] * pow[n - nn] + j * pow[n - nn - best_p[lev]], digits,
x[i] * pow[n - nn] + (j + 1) * pow[n - nn - best_p[lev]] -
1);
ofs += cluster;
jj = i;
for (j = 0; j < k; j++)
if (x[j] > x[i] && (x[j] < x[jj] || jj == i))
jj = j;
i = jj;
}
fprintf (f, "\n};\n\n");
lev++;
write_array (cluster * k);
lev--;
}
static void
write_source (
void
)
{
int i, j;
lev = 0;
s = 0;
nn = n;
t[0] = N;
fprintf (f, "\n" "/* *IND" "ENT-OFF* */\n\n");
write_array (0);
fprintf (f, "/* *IND" "ENT-ON* */\n\n");
fprintf (f, "#define %s(x) \\\n", macro_name);
fprintf (f, "\t((x) >= 0x%lx ? ", N);
if (name)
fprintf (f, "%s", name[def_key]);
else
fprintf (f, "%d", def_key);
fprintf (f, " : ");
j = 0;
for (i = best_lev - 1; i >= 0; i--)
{
fprintf (f, " \\\n\t%sLev%d[((x)", table_name, i);
if (j != 0)
fprintf (f, " >> %d", j);
if (i)
fprintf (f, " & 0x%02lx) +", pow[best_p[best_lev - 1 - i]] - 1);
j += best_p[best_lev - 1 - i];
}
fprintf (f, ")");
for (i = 0; i < best_lev; i++)
fprintf (f, "]");
fprintf (f, ")\n\n");
}
static void
write_out (
void
)
{
int i;
fprintf (f, "/*\n"
" generated by packtab.c version %d\n\n"
" use %s(key) to access your table\n\n"
" assumed sizeof(%s): %d\n"
" required memory: %ld\n"
" lookups: %d\n"
" partition shape: %s",
packtab_version, macro_name, key_type_name, a, best_s, best_lev,
table_name);
for (i = best_lev - 1; i >= 0; i--)
fprintf (f, "[%ld]", best_cluster[i]);
fprintf (f, "\n" " different table entries:");
for (i = best_lev - 1; i >= 0; i--)
fprintf (f, " %ld", best_c[i]);
fprintf (f, "\n*/\n");
write_source ();
}
int
pack_table (
const signed int *base,
long key_num,
int key_size,
signed int default_key,
int p_max_depth,
int p_tab_width,
const char *const *p_name,
const char *p_key_type_name,
const char *p_table_name,
const char *p_macro_name,
FILE *out
)
{
N = key_num;
a = key_size;
def_key = default_key;
max_depth = p_max_depth;
tab_width = p_tab_width;
name = p_name;
key_type_name = p_key_type_name;
table_name = p_table_name;
macro_name = p_macro_name;
f = out;
init (base);
if (!(tab = malloc ((n + 1) * sizeof (tab[0]))))
return 0;
memmove (tab[0], base, N * sizeof (base[0]));
solve ();
write_out ();
free (tab);
return 1;
}
/* End of packtab.c */