Written by Fred Fish <fnf@cygnus.com>
Rewritten by Jim Blandy <jimb@cygnus.com>
- Copyright (C) 1999, 2000, 2002, 2003 Free Software Foundation, Inc.
+ Copyright (C) 1999-2013 Free Software Foundation, Inc.
This file is part of GDB.
This program 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 of the License, or
+ the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 51 Franklin Street, Fifth Floor,
- Boston, MA 02110-1301, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "gdb_obstack.h"
16 bits of hash values) hit, but the corresponding combined
length/data compare missed. */
unsigned long half_hash_miss_count;
+
+ /* Hash function to be used for this bcache object. */
+ unsigned long (*hash_function)(const void *addr, int length);
+
+ /* Compare function to be used for this bcache object. */
+ int (*compare_function)(const void *, const void *, int length);
};
-/* The old hash function was stolen from SDBM. This is what DB 3.0 uses now,
- * and is better than the old one.
- */
+/* The old hash function was stolen from SDBM. This is what DB 3.0
+ uses now, and is better than the old one. */
\f
unsigned long
hash(const void *addr, int length)
{
- const unsigned char *k, *e;
- unsigned long h;
-
- k = (const unsigned char *)addr;
- e = k+length;
- for (h=0; k< e;++k)
- {
- h *=16777619;
- h ^= *k;
- }
- return (h);
+ return hash_continue (addr, length, 0);
+}
+
+/* Continue the calculation of the hash H at the given address. */
+
+unsigned long
+hash_continue (const void *addr, int length, unsigned long h)
+{
+ const unsigned char *k, *e;
+
+ k = (const unsigned char *)addr;
+ e = k+length;
+ for (; k< e;++k)
+ {
+ h *=16777619;
+ h ^= *k;
+ }
+ return (h);
}
\f
/* Growing the bcache's hash table. */
/* Allocate the new table. */
{
size_t new_size = new_num_buckets * sizeof (new_buckets[0]);
+
new_buckets = (struct bstring **) xmalloc (new_size);
memset (new_buckets, 0, new_size);
struct bstring **new_bucket;
next = s->next;
- new_bucket = &new_buckets[(hash (&s->d.data, s->length)
+ new_bucket = &new_buckets[(bcache->hash_function (&s->d.data,
+ s->length)
% new_num_buckets)];
s->next = *new_bucket;
*new_bucket = s;
/* Find a copy of the LENGTH bytes at ADDR in BCACHE. If BCACHE has
never seen those bytes before, add a copy of them to BCACHE. In
either case, return a pointer to BCACHE's copy of that string. */
-static void *
-bcache_data (const void *addr, int length, struct bcache *bcache)
+const void *
+bcache (const void *addr, int length, struct bcache *cache)
+{
+ return bcache_full (addr, length, cache, NULL);
+}
+
+/* Find a copy of the LENGTH bytes at ADDR in BCACHE. If BCACHE has
+ never seen those bytes before, add a copy of them to BCACHE. In
+ either case, return a pointer to BCACHE's copy of that string. If
+ optional ADDED is not NULL, return 1 in case of new entry or 0 if
+ returning an old entry. */
+
+const void *
+bcache_full (const void *addr, int length, struct bcache *bcache, int *added)
{
unsigned long full_hash;
unsigned short half_hash;
int hash_index;
struct bstring *s;
+ if (added)
+ *added = 0;
+
+ /* Lazily initialize the obstack. This can save quite a bit of
+ memory in some cases. */
+ if (bcache->total_count == 0)
+ {
+ /* We could use obstack_specify_allocation here instead, but
+ gdb_obstack.h specifies the allocation/deallocation
+ functions. */
+ obstack_init (&bcache->cache);
+ }
+
/* If our average chain length is too high, expand the hash table. */
if (bcache->unique_count >= bcache->num_buckets * CHAIN_LENGTH_THRESHOLD)
expand_hash_table (bcache);
bcache->total_count++;
bcache->total_size += length;
- full_hash = hash (addr, length);
+ full_hash = bcache->hash_function (addr, length);
+
half_hash = (full_hash >> 16);
hash_index = full_hash % bcache->num_buckets;
if (s->half_hash == half_hash)
{
if (s->length == length
- && ! memcmp (&s->d.data, addr, length))
+ && bcache->compare_function (&s->d.data, addr, length))
return &s->d.data;
else
bcache->half_hash_miss_count++;
{
struct bstring *new
= obstack_alloc (&bcache->cache, BSTRING_SIZE (length));
+
memcpy (&new->d.data, addr, length);
new->length = length;
new->next = bcache->bucket[hash_index];
bcache->unique_size += length;
bcache->structure_size += BSTRING_SIZE (length);
+ if (added)
+ *added = 1;
+
return &new->d.data;
}
}
+\f
-void *
-deprecated_bcache (const void *addr, int length, struct bcache *bcache)
-{
- return bcache_data (addr, length, bcache);
-}
+/* Compare the byte string at ADDR1 of lenght LENGHT to the
+ string at ADDR2. Return 1 if they are equal. */
-const void *
-bcache (const void *addr, int length, struct bcache *bcache)
+static int
+bcache_compare (const void *addr1, const void *addr2, int length)
{
- return bcache_data (addr, length, bcache);
+ return memcmp (addr1, addr2, length) == 0;
}
-\f
+
/* Allocating and freeing bcaches. */
+/* Allocated a bcache. HASH_FUNCTION and COMPARE_FUNCTION can be used
+ to pass in custom hash, and compare functions to be used by this
+ bcache. If HASH_FUNCTION is NULL hash() is used and if
+ COMPARE_FUNCTION is NULL memcmp() is used. */
+
struct bcache *
-bcache_xmalloc (void)
+bcache_xmalloc (unsigned long (*hash_function)(const void *, int length),
+ int (*compare_function)(const void *,
+ const void *,
+ int length))
{
/* Allocate the bcache pre-zeroed. */
struct bcache *b = XCALLOC (1, struct bcache);
- /* We could use obstack_specify_allocation here instead, but
- gdb_obstack.h specifies the allocation/deallocation
- functions. */
- obstack_init (&b->cache);
+
+ if (hash_function)
+ b->hash_function = hash_function;
+ else
+ b->hash_function = hash;
+
+ if (compare_function)
+ b->compare_function = compare_function;
+ else
+ b->compare_function = bcache_compare;
return b;
}
{
if (bcache == NULL)
return;
- obstack_free (&bcache->cache, 0);
+ /* Only free the obstack if we actually initialized it. */
+ if (bcache->total_count > 0)
+ obstack_free (&bcache->cache, 0);
xfree (bcache->bucket);
xfree (bcache);
}
\f
/* Printing statistics. */
-static int
-compare_ints (const void *ap, const void *bp)
-{
- /* Because we know we're comparing two ints which are positive,
- there's no danger of overflow here. */
- return * (int *) ap - * (int *) bp;
-}
-
-
static void
print_percentage (int portion, int total)
{
if (total == 0)
- /* i18n: Like "Percentage of duplicates, by count: (not applicable)" */
+ /* i18n: Like "Percentage of duplicates, by count: (not applicable)". */
printf_filtered (_("(not applicable)\n"));
else
printf_filtered ("%3d%%\n", (int) (portion * 100.0 / total));
}
}
- /* To compute the median, we need the set of chain lengths sorted. */
+ /* To compute the median, we need the set of chain lengths
+ sorted. */
qsort (chain_length, c->num_buckets, sizeof (chain_length[0]),
- compare_ints);
+ compare_positive_ints);
qsort (entry_size, c->unique_count, sizeof (entry_size[0]),
- compare_ints);
+ compare_positive_ints);
if (c->num_buckets > 0)
{
if (c->unique_count > 0)
printf_filtered ("%ld\n", c->unique_size / c->unique_count);
else
- /* i18n: "Average entry size: (not applicable)" */
+ /* i18n: "Average entry size: (not applicable)". */
printf_filtered (_("(not applicable)\n"));
printf_filtered (_(" Median entry size: %d\n"), median_entry_size);
printf_filtered ("\n");
- printf_filtered (_(" Total memory used by bcache, including overhead: %ld\n"),
+ printf_filtered (_(" \
+Total memory used by bcache, including overhead: %ld\n"),
c->structure_size);
printf_filtered (_(" Percentage memory overhead: "));
print_percentage (c->structure_size - c->unique_size, c->unique_size);
print_percentage (c->total_size - c->structure_size, c->total_size);
printf_filtered ("\n");
- printf_filtered (_(" Hash table size: %3d\n"), c->num_buckets);
+ printf_filtered (_(" Hash table size: %3d\n"),
+ c->num_buckets);
printf_filtered (_(" Hash table expands: %lu\n"),
c->expand_count);
printf_filtered (_(" Hash table hashes: %lu\n"),
if (c->num_buckets > 0)
printf_filtered ("%3lu\n", c->unique_count / c->num_buckets);
else
- /* i18n: "Average hash chain length: (not applicable)" */
+ /* i18n: "Average hash chain length: (not applicable)". */
printf_filtered (_("(not applicable)\n"));
- printf_filtered (_(" Maximum hash chain length: %3d\n"), max_chain_length);
+ printf_filtered (_(" Maximum hash chain length: %3d\n"),
+ max_chain_length);
printf_filtered ("\n");
}
int
bcache_memory_used (struct bcache *bcache)
{
+ if (bcache->total_count == 0)
+ return 0;
return obstack_memory_used (&bcache->cache);
}
projects / deliverable / binutils-gdb.git / blobdiff