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Simplify implementation of hashtable.c 

Issue #26588: Remove copy_data, free_data and get_data_size callbacks from
hashtable.h. These callbacks are not used in Python and makes the code more
complex.

Remove also the _Py_HASHTABLE_ENTRY_DATA_AS_VOID_P() macro which uses an unsafe
pointer dereference (can cause memory alignment issue). Replace the macro usage
with _Py_HASHTABLE_ENTRY_READ_DATA() which is implemented with the safe
memcpy() function.
This commit is contained in:
Victor Stinner 2016-03-22 12:13:01 +01:00
parent 0b2d71bc70
commit c9553876ae
3 changed files with 17 additions and 66 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
Modules/_tracemalloc.c
View File

@ -220,16 +220,15 @@ hashtable_compare_unicode(size_t key_size, const void *pkey,
return key == entry_key;
}
static _Py_hashtable_allocator_t hashtable_alloc = {malloc, free};
static _Py_hashtable_t *
hashtable_new(size_t key_size, size_t data_size,
_Py_hashtable_hash_func hash_func,
_Py_hashtable_compare_func compare_func)
{
_Py_hashtable_allocator_t hashtable_alloc = {malloc, free};
return _Py_hashtable_new_full(key_size, data_size, 0,
hash_func, compare_func,
NULL, NULL, NULL, &hashtable_alloc);
&hashtable_alloc);
}
static void*
@ -1120,7 +1119,8 @@ tracemalloc_pyobject_decref_cb(_Py_hashtable_t *tracebacks,
_Py_hashtable_entry_t *entry,
void *user_data)
{
PyObject *obj = (PyObject *)_Py_HASHTABLE_ENTRY_DATA_AS_VOID_P(tracebacks, entry);
PyObject *obj;
_Py_HASHTABLE_ENTRY_READ_DATA(tracebacks, entry, sizeof(obj), &obj);
Py_DECREF(obj);
return 0;
}
@ -1151,7 +1151,8 @@ py_tracemalloc_get_traces(PyObject *self, PyObject *obj)
/* the traceback hash table is used temporarily to intern traceback tuple
of (filename, lineno) tuples */
get_traces.tracebacks = hashtable_new(sizeof(traceback_t *), sizeof(PyObject *),
get_traces.tracebacks = hashtable_new(sizeof(traceback_t *),
sizeof(PyObject *),
_Py_hashtable_hash_ptr,
_Py_hashtable_compare_direct);
if (get_traces.tracebacks == NULL) {
@ -1186,8 +1187,9 @@ finally:
tracemalloc_pyobject_decref_cb, NULL);
_Py_hashtable_destroy(get_traces.tracebacks);
}
if (get_traces.traces != NULL)
if (get_traces.traces != NULL) {
_Py_hashtable_destroy(get_traces.traces);
}
return get_traces.list;
}

55
Modules/hashtable.c
View File

@ -128,9 +128,6 @@ _Py_hashtable_new_full(size_t key_size, size_t data_size,
size_t init_size,
_Py_hashtable_hash_func hash_func,
_Py_hashtable_compare_func compare_func,
_Py_hashtable_copy_data_func copy_data_func,
_Py_hashtable_free_data_func free_data_func,
_Py_hashtable_get_data_size_func get_data_size_func,
_Py_hashtable_allocator_t *allocator)
{
_Py_hashtable_t *ht;
@ -163,9 +160,6 @@ _Py_hashtable_new_full(size_t key_size, size_t data_size,
ht->hash_func = hash_func;
ht->compare_func = compare_func;
ht->copy_data_func = copy_data_func;
ht->free_data_func = free_data_func;
ht->get_data_size_func = get_data_size_func;
ht->alloc = alloc;
return ht;
}
@ -179,7 +173,7 @@ _Py_hashtable_new(size_t key_size, size_t data_size,
return _Py_hashtable_new_full(key_size, data_size,
HASHTABLE_MIN_SIZE,
hash_func, compare_func,
NULL, NULL, NULL, NULL);
NULL);
}
@ -187,7 +181,6 @@ size_t
_Py_hashtable_size(_Py_hashtable_t *ht)
{
size_t size;
size_t hv;
size = sizeof(_Py_hashtable_t);
@ -197,19 +190,6 @@ _Py_hashtable_size(_Py_hashtable_t *ht)
/* entries */
size += ht->entries * HASHTABLE_ITEM_SIZE(ht);
/* data linked from entries */
if (ht->get_data_size_func) {
for (hv = 0; hv < ht->num_buckets; hv++) {
_Py_hashtable_entry_t *entry;
for (entry = TABLE_HEAD(ht, hv); entry; entry = ENTRY_NEXT(entry)) {
void *data;
data = _Py_HASHTABLE_ENTRY_DATA_AS_VOID_P(ht, entry);
size += ht->get_data_size_func(data);
}
}
}
return size;
}
@ -318,7 +298,7 @@ _Py_hashtable_pop_entry(_Py_hashtable_t *ht, size_t key_size, const void *pkey,
int
_Py_hashtable_set(_Py_hashtable_t *ht, size_t key_size, const void *pkey,
size_t data_size, void *data)
size_t data_size, const void *data)
{
Py_uhash_t key_hash;
size_t index;
@ -380,7 +360,6 @@ _Py_hashtable_pop(_Py_hashtable_t *ht, size_t key_size, const void *pkey,
size_t data_size, void *data)
{
assert(data != NULL);
assert(ht->free_data_func == NULL);
return _Py_hashtable_pop_entry(ht, key_size, pkey, data, data_size);
}
@ -470,8 +449,6 @@ _Py_hashtable_clear(_Py_hashtable_t *ht)
for (i=0; i < ht->num_buckets; i++) {
for (entry = TABLE_HEAD(ht, i); entry != NULL; entry = next) {
next = ENTRY_NEXT(entry);
if (ht->free_data_func)
ht->free_data_func(_Py_HASHTABLE_ENTRY_DATA_AS_VOID_P(ht, entry));
ht->alloc.free(entry);
}
_Py_slist_init(&ht->buckets[i]);
@ -490,8 +467,6 @@ _Py_hashtable_destroy(_Py_hashtable_t *ht)
_Py_slist_item_t *entry = ht->buckets[i].head;
while (entry) {
_Py_slist_item_t *entry_next = entry->next;
if (ht->free_data_func)
ht->free_data_func(_Py_HASHTABLE_ENTRY_DATA_AS_VOID_P(ht, entry));
ht->alloc.free(entry);
entry = entry_next;
}
@ -511,35 +486,21 @@ _Py_hashtable_copy(_Py_hashtable_t *src)
_Py_hashtable_entry_t *entry;
size_t bucket;
int err;
void *data, *new_data;
dst = _Py_hashtable_new_full(key_size, data_size,
src->num_buckets,
src->hash_func, src->compare_func,
src->copy_data_func, src->free_data_func,
src->get_data_size_func, &src->alloc);
src->hash_func,
src->compare_func,
&src->alloc);
if (dst == NULL)
return NULL;
for (bucket=0; bucket < src->num_buckets; bucket++) {
entry = TABLE_HEAD(src, bucket);
for (; entry; entry = ENTRY_NEXT(entry)) {
if (src->copy_data_func) {
data = _Py_HASHTABLE_ENTRY_DATA_AS_VOID_P(src, entry);
new_data = src->copy_data_func(data);
if (new_data != NULL)
err = _Py_hashtable_set(dst, key_size,
_Py_HASHTABLE_ENTRY_KEY(entry),
data_size, &new_data);
else
err = 1;
}
else {
data = _Py_HASHTABLE_ENTRY_DATA(src, entry);
err = _Py_hashtable_set(dst, key_size,
_Py_HASHTABLE_ENTRY_KEY(entry),
data_size, data);
}
const void *pkey = _Py_HASHTABLE_ENTRY_KEY(entry);
const void *data = _Py_HASHTABLE_ENTRY_DATA(src, entry);
err = _Py_hashtable_set(dst, key_size, pkey, data_size, data);
if (err) {
_Py_hashtable_destroy(dst);
return NULL;

14
Modules/hashtable.h
View File

@ -35,9 +35,6 @@ typedef struct {
#define _Py_HASHTABLE_ENTRY_DATA(TABLE, ENTRY) \
((char *)(ENTRY) + sizeof(_Py_hashtable_entry_t) + (TABLE)->key_size)
#define _Py_HASHTABLE_ENTRY_DATA_AS_VOID_P(TABLE, ENTRY) \
(*(void **)_Py_HASHTABLE_ENTRY_DATA(TABLE, ENTRY))
/* Get a key value from pkey: use memcpy() rather than a pointer dereference
to avoid memory alignment issues. */
#define _Py_HASHTABLE_READ_KEY(KEY_SIZE, PKEY, DST_KEY) \
@ -66,9 +63,6 @@ typedef Py_uhash_t (*_Py_hashtable_hash_func) (size_t key_size,
typedef int (*_Py_hashtable_compare_func) (size_t key_size,
const void *pkey,
const _Py_hashtable_entry_t *he);
typedef void* (*_Py_hashtable_copy_data_func)(void *data);
typedef void (*_Py_hashtable_free_data_func)(void *data);
typedef size_t (*_Py_hashtable_get_data_size_func)(void *data);
typedef struct {
/* allocate a memory block */
@ -90,9 +84,6 @@ typedef struct {
_Py_hashtable_hash_func hash_func;
_Py_hashtable_compare_func compare_func;
_Py_hashtable_copy_data_func copy_data_func;
_Py_hashtable_free_data_func free_data_func;
_Py_hashtable_get_data_size_func get_data_size_func;
_Py_hashtable_allocator_t alloc;
} _Py_hashtable_t;
@ -119,9 +110,6 @@ PyAPI_FUNC(_Py_hashtable_t *) _Py_hashtable_new_full(
size_t init_size,
_Py_hashtable_hash_func hash_func,
_Py_hashtable_compare_func compare_func,
_Py_hashtable_copy_data_func copy_data_func,
_Py_hashtable_free_data_func free_data_func,
_Py_hashtable_get_data_size_func get_data_size_func,
_Py_hashtable_allocator_t *allocator);
PyAPI_FUNC(void) _Py_hashtable_destroy(_Py_hashtable_t *ht);
@ -155,7 +143,7 @@ PyAPI_FUNC(int) _Py_hashtable_set(
size_t key_size,
const void *pkey,
size_t data_size,
void *data);
const void *data);
#define _Py_HASHTABLE_SET(TABLE, KEY, DATA) \
_Py_hashtable_set(TABLE, sizeof(KEY), &KEY, sizeof(DATA), &(DATA))