Written by Fred Fish <fnf@cygnus.com>
Rewritten by Jim Blandy <jimb@cygnus.com>
- Copyright (C) 1999-2019 Free Software Foundation, Inc.
+ Copyright (C) 1999-2024 Free Software Foundation, Inc.
This file is part of GDB.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
-#include "defs.h"
-#include "gdb_obstack.h"
+#include "gdbsupport/gdb_obstack.h"
#include "bcache.h"
+#include <algorithm>
+
+namespace gdb {
+
/* The type used to hold a single bcache string. The user data is
stored in d.data. Since it can be any type, it needs to have the
same alignment as the most strict alignment of any type on the host
d;
};
-
-/* The structure for a bcache itself. The bcache is initialized, in
- bcache_xmalloc(), by filling it with zeros and then setting the
- corresponding obstack's malloc() and free() methods. */
-
-struct bcache
-{
- /* All the bstrings are allocated here. */
- struct obstack cache;
-
- /* How many hash buckets we're using. */
- unsigned int num_buckets;
-
- /* Hash buckets. This table is allocated using malloc, so when we
- grow the table we can return the old table to the system. */
- struct bstring **bucket;
-
- /* Statistics. */
- unsigned long unique_count; /* number of unique strings */
- long total_count; /* total number of strings cached, including dups */
- long unique_size; /* size of unique strings, in bytes */
- long total_size; /* total number of bytes cached, including dups */
- long structure_size; /* total size of bcache, including infrastructure */
- /* Number of times that the hash table is expanded and hence
- re-built, and the corresponding number of times that a string is
- [re]hashed as part of entering it into the expanded table. The
- total number of hashes can be computed by adding TOTAL_COUNT to
- expand_hash_count. */
- unsigned long expand_count;
- unsigned long expand_hash_count;
- /* Number of times that the half-hash compare hit (compare the upper
- 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. */
-\f
-unsigned long
-hash(const void *addr, int length)
-{
- 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. */
resize our hash table. */
#define CHAIN_LENGTH_THRESHOLD (5)
-static void
-expand_hash_table (struct bcache *bcache)
+void
+bcache::expand_hash_table ()
{
/* A table of good hash table sizes. Whenever we grow, we pick the
next larger size from this table. sizes[i] is close to 1 << (i+10),
so we roughly double the table size each time. After we fall off
the end of this table, we just double. Don't laugh --- there have
been executables sighted with a gigabyte of debug info. */
- static unsigned long sizes[] = {
+ static const unsigned long sizes[] = {
1021, 2053, 4099, 8191, 16381, 32771,
65537, 131071, 262144, 524287, 1048573, 2097143,
4194301, 8388617, 16777213, 33554467, 67108859, 134217757,
/* Count the stats. Every unique item needs to be re-hashed and
re-entered. */
- bcache->expand_count++;
- bcache->expand_hash_count += bcache->unique_count;
+ m_expand_count++;
+ m_expand_hash_count += m_unique_count;
/* Find the next size. */
- new_num_buckets = bcache->num_buckets * 2;
- for (i = 0; i < (sizeof (sizes) / sizeof (sizes[0])); i++)
- if (sizes[i] > bcache->num_buckets)
+ new_num_buckets = m_num_buckets * 2;
+ for (unsigned long a_size : sizes)
+ if (a_size > m_num_buckets)
{
- new_num_buckets = sizes[i];
+ new_num_buckets = a_size;
break;
}
new_buckets = (struct bstring **) xmalloc (new_size);
memset (new_buckets, 0, new_size);
- bcache->structure_size -= (bcache->num_buckets
- * sizeof (bcache->bucket[0]));
- bcache->structure_size += new_size;
+ m_structure_size -= m_num_buckets * sizeof (m_bucket[0]);
+ m_structure_size += new_size;
}
/* Rehash all existing strings. */
- for (i = 0; i < bcache->num_buckets; i++)
+ for (i = 0; i < m_num_buckets; i++)
{
struct bstring *s, *next;
- for (s = bcache->bucket[i]; s; s = next)
+ for (s = m_bucket[i]; s; s = next)
{
struct bstring **new_bucket;
next = s->next;
- new_bucket = &new_buckets[(bcache->hash_function (&s->d.data,
- s->length)
+ new_bucket = &new_buckets[(this->hash (&s->d.data, s->length)
% new_num_buckets)];
s->next = *new_bucket;
*new_bucket = s;
}
/* Plug in the new table. */
- if (bcache->bucket)
- xfree (bcache->bucket);
- bcache->bucket = new_buckets;
- bcache->num_buckets = new_num_buckets;
+ xfree (m_bucket);
+ m_bucket = new_buckets;
+ m_num_buckets = new_num_buckets;
}
\f
is N bytes long. */
#define BSTRING_SIZE(n) (offsetof (struct bstring, d.data) + (n))
-/* 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. */
-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
returning an old entry. */
const void *
-bcache_full (const void *addr, int length, struct bcache *bcache, int *added)
+bcache::insert (const void *addr, int length, bool *added)
{
unsigned long full_hash;
unsigned short half_hash;
int hash_index;
struct bstring *s;
- if (added)
- *added = 0;
+ if (added != nullptr)
+ *added = false;
/* Lazily initialize the obstack. This can save quite a bit of
memory in some cases. */
- if (bcache->total_count == 0)
+ if (m_total_count == 0)
{
/* We could use obstack_specify_allocation here instead, but
gdb_obstack.h specifies the allocation/deallocation
functions. */
- obstack_init (&bcache->cache);
+ obstack_init (&m_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);
+ if (m_unique_count >= m_num_buckets * CHAIN_LENGTH_THRESHOLD)
+ expand_hash_table ();
- bcache->total_count++;
- bcache->total_size += length;
+ m_total_count++;
+ m_total_size += length;
- full_hash = bcache->hash_function (addr, length);
+ full_hash = this->hash (addr, length);
half_hash = (full_hash >> 16);
- hash_index = full_hash % bcache->num_buckets;
+ hash_index = full_hash % m_num_buckets;
- /* Search the hash bucket for a string identical to the caller's.
+ /* Search the hash m_bucket for a string identical to the caller's.
As a short-circuit first compare the upper part of each hash
values. */
- for (s = bcache->bucket[hash_index]; s; s = s->next)
+ for (s = m_bucket[hash_index]; s; s = s->next)
{
if (s->half_hash == half_hash)
{
if (s->length == length
- && bcache->compare_function (&s->d.data, addr, length))
+ && this->compare (&s->d.data, addr, length))
return &s->d.data;
else
- bcache->half_hash_miss_count++;
+ m_half_hash_miss_count++;
}
}
/* The user's string isn't in the list. Insert it after *ps. */
{
struct bstring *newobj
- = (struct bstring *) obstack_alloc (&bcache->cache,
+ = (struct bstring *) obstack_alloc (&m_cache,
BSTRING_SIZE (length));
memcpy (&newobj->d.data, addr, length);
newobj->length = length;
- newobj->next = bcache->bucket[hash_index];
+ newobj->next = m_bucket[hash_index];
newobj->half_hash = half_hash;
- bcache->bucket[hash_index] = newobj;
+ m_bucket[hash_index] = newobj;
- bcache->unique_count++;
- bcache->unique_size += length;
- bcache->structure_size += BSTRING_SIZE (length);
+ m_unique_count++;
+ m_unique_size += length;
+ m_structure_size += BSTRING_SIZE (length);
- if (added)
- *added = 1;
+ if (added != nullptr)
+ *added = true;
return &newobj->d.data;
}
}
\f
-/* Compare the byte string at ADDR1 of lenght LENGHT to the
- string at ADDR2. Return 1 if they are equal. */
+/* See bcache.h. */
-static int
-bcache_compare (const void *addr1, const void *addr2, int length)
+unsigned long
+bcache::hash (const void *addr, int length)
{
- return memcmp (addr1, addr2, length) == 0;
+ return fast_hash (addr, length, 0);
}
-/* 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. */
+/* See bcache.h. */
-struct bcache *
-bcache_xmalloc (unsigned long (*hash_function)(const void *, int length),
- int (*compare_function)(const void *,
- const void *,
- int length))
+int
+bcache::compare (const void *left, const void *right, int length)
{
- /* Allocate the bcache pre-zeroed. */
- struct bcache *b = XCNEW (struct bcache);
-
- 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;
+ return memcmp (left, right, length) == 0;
}
/* Free all the storage associated with BCACHE. */
-void
-bcache_xfree (struct bcache *bcache)
+bcache::~bcache ()
{
- if (bcache == NULL)
- return;
/* Only free the obstack if we actually initialized it. */
- if (bcache->total_count > 0)
- obstack_free (&bcache->cache, 0);
- xfree (bcache->bucket);
- xfree (bcache);
+ if (m_total_count > 0)
+ obstack_free (&m_cache, 0);
+ xfree (m_bucket);
}
{
if (total == 0)
/* i18n: Like "Percentage of duplicates, by count: (not applicable)". */
- printf_filtered (_("(not applicable)\n"));
+ gdb_printf (_("(not applicable)\n"));
else
- printf_filtered ("%3d%%\n", (int) (portion * 100.0 / total));
+ gdb_printf ("%3d%%\n", (int) (portion * 100.0 / total));
}
/* Print statistics on BCACHE's memory usage and efficacity at
eliminating duplication. NAME should describe the kind of data
- BCACHE holds. Statistics are printed using `printf_filtered' and
+ BCACHE holds. Statistics are printed using `gdb_printf' and
its ilk. */
void
-print_bcache_statistics (struct bcache *c, const char *type)
+bcache::print_statistics (const char *type)
{
int occupied_buckets;
int max_chain_length;
lengths, and measure chain lengths. */
{
unsigned int b;
- int *chain_length = XCNEWVEC (int, c->num_buckets + 1);
- int *entry_size = XCNEWVEC (int, c->unique_count + 1);
+ int *chain_length = XCNEWVEC (int, m_num_buckets + 1);
+ int *entry_size = XCNEWVEC (int, m_unique_count + 1);
int stringi = 0;
occupied_buckets = 0;
- for (b = 0; b < c->num_buckets; b++)
+ for (b = 0; b < m_num_buckets; b++)
{
- struct bstring *s = c->bucket[b];
+ struct bstring *s = m_bucket[b];
chain_length[b] = 0;
while (s)
{
- gdb_assert (b < c->num_buckets);
+ gdb_assert (b < m_num_buckets);
chain_length[b]++;
- gdb_assert (stringi < c->unique_count);
+ gdb_assert (stringi < m_unique_count);
entry_size[stringi++] = s->length;
s = s->next;
}
/* To compute the median, we need the set of chain lengths
sorted. */
- qsort (chain_length, c->num_buckets, sizeof (chain_length[0]),
- compare_positive_ints);
- qsort (entry_size, c->unique_count, sizeof (entry_size[0]),
- compare_positive_ints);
+ std::sort (chain_length, chain_length + m_num_buckets);
+ std::sort (entry_size, entry_size + m_unique_count);
- if (c->num_buckets > 0)
+ if (m_num_buckets > 0)
{
- max_chain_length = chain_length[c->num_buckets - 1];
- median_chain_length = chain_length[c->num_buckets / 2];
+ max_chain_length = chain_length[m_num_buckets - 1];
+ median_chain_length = chain_length[m_num_buckets / 2];
}
else
{
max_chain_length = 0;
median_chain_length = 0;
}
- if (c->unique_count > 0)
+ if (m_unique_count > 0)
{
- max_entry_size = entry_size[c->unique_count - 1];
- median_entry_size = entry_size[c->unique_count / 2];
+ max_entry_size = entry_size[m_unique_count - 1];
+ median_entry_size = entry_size[m_unique_count / 2];
}
else
{
xfree (entry_size);
}
- printf_filtered (_(" Cached '%s' statistics:\n"), type);
- printf_filtered (_(" Total object count: %ld\n"), c->total_count);
- printf_filtered (_(" Unique object count: %lu\n"), c->unique_count);
- printf_filtered (_(" Percentage of duplicates, by count: "));
- print_percentage (c->total_count - c->unique_count, c->total_count);
- printf_filtered ("\n");
-
- printf_filtered (_(" Total object size: %ld\n"), c->total_size);
- printf_filtered (_(" Unique object size: %ld\n"), c->unique_size);
- printf_filtered (_(" Percentage of duplicates, by size: "));
- print_percentage (c->total_size - c->unique_size, c->total_size);
- printf_filtered ("\n");
-
- printf_filtered (_(" Max entry size: %d\n"), max_entry_size);
- printf_filtered (_(" Average entry size: "));
- if (c->unique_count > 0)
- printf_filtered ("%ld\n", c->unique_size / c->unique_count);
+ gdb_printf (_(" M_Cached '%s' statistics:\n"), type);
+ gdb_printf (_(" Total object count: %ld\n"), m_total_count);
+ gdb_printf (_(" Unique object count: %lu\n"), m_unique_count);
+ gdb_printf (_(" Percentage of duplicates, by count: "));
+ print_percentage (m_total_count - m_unique_count, m_total_count);
+ gdb_printf ("\n");
+
+ gdb_printf (_(" Total object size: %ld\n"), m_total_size);
+ gdb_printf (_(" Unique object size: %ld\n"), m_unique_size);
+ gdb_printf (_(" Percentage of duplicates, by size: "));
+ print_percentage (m_total_size - m_unique_size, m_total_size);
+ gdb_printf ("\n");
+
+ gdb_printf (_(" Max entry size: %d\n"), max_entry_size);
+ gdb_printf (_(" Average entry size: "));
+ if (m_unique_count > 0)
+ gdb_printf ("%ld\n", m_unique_size / m_unique_count);
else
/* i18n: "Average entry size: (not applicable)". */
- printf_filtered (_("(not applicable)\n"));
- printf_filtered (_(" Median entry size: %d\n"), median_entry_size);
- printf_filtered ("\n");
+ gdb_printf (_("(not applicable)\n"));
+ gdb_printf (_(" Median entry size: %d\n"), median_entry_size);
+ gdb_printf ("\n");
- printf_filtered (_(" \
+ gdb_printf (_(" \
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);
- printf_filtered (_(" Net memory savings: "));
- 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 expands: %lu\n"),
- c->expand_count);
- printf_filtered (_(" Hash table hashes: %lu\n"),
- c->total_count + c->expand_hash_count);
- printf_filtered (_(" Half hash misses: %lu\n"),
- c->half_hash_miss_count);
- printf_filtered (_(" Hash table population: "));
- print_percentage (occupied_buckets, c->num_buckets);
- printf_filtered (_(" Median hash chain length: %3d\n"),
- median_chain_length);
- printf_filtered (_(" Average hash chain length: "));
- if (c->num_buckets > 0)
- printf_filtered ("%3lu\n", c->unique_count / c->num_buckets);
+ m_structure_size);
+ gdb_printf (_(" Percentage memory overhead: "));
+ print_percentage (m_structure_size - m_unique_size, m_unique_size);
+ gdb_printf (_(" Net memory savings: "));
+ print_percentage (m_total_size - m_structure_size, m_total_size);
+ gdb_printf ("\n");
+
+ gdb_printf (_(" Hash table size: %3d\n"),
+ m_num_buckets);
+ gdb_printf (_(" Hash table expands: %lu\n"),
+ m_expand_count);
+ gdb_printf (_(" Hash table hashes: %lu\n"),
+ m_total_count + m_expand_hash_count);
+ gdb_printf (_(" Half hash misses: %lu\n"),
+ m_half_hash_miss_count);
+ gdb_printf (_(" Hash table population: "));
+ print_percentage (occupied_buckets, m_num_buckets);
+ gdb_printf (_(" Median hash chain length: %3d\n"),
+ median_chain_length);
+ gdb_printf (_(" Average hash chain length: "));
+ if (m_num_buckets > 0)
+ gdb_printf ("%3lu\n", m_unique_count / m_num_buckets);
else
/* 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 ("\n");
+ gdb_printf (_("(not applicable)\n"));
+ gdb_printf (_(" Maximum hash chain length: %3d\n"),
+ max_chain_length);
+ gdb_printf ("\n");
}
int
-bcache_memory_used (struct bcache *bcache)
+bcache::memory_used ()
{
- if (bcache->total_count == 0)
+ if (m_total_count == 0)
return 0;
- return obstack_memory_used (&bcache->cache);
+ return obstack_memory_used (&m_cache);
}
+
+} /* namespace gdb */
projects / thirdparty / binutils-gdb.git / blobdiff