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hashtable.h now supports keys of any size

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Issue #26588: hashtable.h now supports keys of any size, not only
sizeof(void*). It allows to support key larger than sizeof(void*), but also to
use less memory for key smaller than sizeof(void*).
This commit is contained in:
Victor Stinner 2016-03-21 22:00:58 +01:00
parent 928bff0b26
commit 285cf0a601
4 changed files with 299 additions and 143 deletions
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173
Modules/hashtable.h
View file

@ -1,9 +1,10 @@
#ifndef Py_HASHTABLE_H
#define Py_HASHTABLE_H
/* The whole API is private */
#ifndef Py_LIMITED_API
/* Single linked list */
typedef struct _Py_slist_item_s {
struct _Py_slist_item_s *next;
} _Py_slist_item_t;
@ -16,30 +17,55 @@ typedef struct {
#define _Py_SLIST_HEAD(SLIST) (((_Py_slist_t *)SLIST)->head)
/* _Py_hashtable: table entry */
typedef struct {
/* used by _Py_hashtable_t.buckets to link entries */
_Py_slist_item_t _Py_slist_item;
const void *key;
Py_uhash_t key_hash;
/* data follows */
/* key (key_size bytes) and then data (data_size bytes) follows */
} _Py_hashtable_entry_t;
#define _Py_HASHTABLE_ENTRY_DATA(ENTRY) \
((char *)(ENTRY) + sizeof(_Py_hashtable_entry_t))
#define _Py_HASHTABLE_ENTRY_KEY(ENTRY) \
((const void *)((char *)(ENTRY) + sizeof(_Py_hashtable_entry_t)))
#define _Py_HASHTABLE_ENTRY_DATA_AS_VOID_P(ENTRY) \
(*(void **)_Py_HASHTABLE_ENTRY_DATA(ENTRY))
#define _Py_HASHTABLE_ENTRY_DATA(TABLE, ENTRY) \
((char *)(ENTRY) + sizeof(_Py_hashtable_entry_t) + (TABLE)->key_size)
#define _Py_HASHTABLE_ENTRY_READ_DATA(TABLE, DATA, DATA_SIZE, ENTRY) \
#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) \
do { \
assert((DATA_SIZE) == (TABLE)->data_size); \
memcpy(DATA, _Py_HASHTABLE_ENTRY_DATA(ENTRY), DATA_SIZE); \
assert(sizeof(DST_KEY) == (KEY_SIZE)); \
memcpy(&(DST_KEY), (PKEY), sizeof(DST_KEY)); \
} while (0)
typedef Py_uhash_t (*_Py_hashtable_hash_func) (const void *key);
typedef int (*_Py_hashtable_compare_func) (const void *key, const _Py_hashtable_entry_t *he);
#define _Py_HASHTABLE_ENTRY_READ_KEY(KEY_SIZE, ENTRY, KEY) \
do { \
assert(sizeof(KEY) == (KEY_SIZE)); \
memcpy(&(KEY), _Py_HASHTABLE_ENTRY_KEY(ENTRY), sizeof(KEY)); \
} while (0)
#define _Py_HASHTABLE_ENTRY_READ_DATA(TABLE, ENTRY, DATA_SIZE, DATA) \
do { \
assert((DATA_SIZE) == (TABLE)->data_size); \
memcpy(DATA, _Py_HASHTABLE_ENTRY_DATA(TABLE, ENTRY), DATA_SIZE); \
} while (0)
/* _Py_hashtable: prototypes */
typedef Py_uhash_t (*_Py_hashtable_hash_func) (size_t key_size,
const void *pkey);
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);
@ -52,10 +78,14 @@ typedef struct {
void (*free) (void *ptr);
} _Py_hashtable_allocator_t;
/* _Py_hashtable: table */
typedef struct {
size_t num_buckets;
size_t entries; /* Total number of entries in the table. */
_Py_slist_t *buckets;
size_t key_size;
size_t data_size;
_Py_hashtable_hash_func hash_func;
@ -66,16 +96,25 @@ typedef struct {
_Py_hashtable_allocator_t alloc;
} _Py_hashtable_t;
/* hash and compare functions for integers and pointers */
PyAPI_FUNC(Py_uhash_t) _Py_hashtable_hash_ptr(const void *key);
PyAPI_FUNC(Py_uhash_t) _Py_hashtable_hash_int(const void *key);
PyAPI_FUNC(int) _Py_hashtable_compare_direct(const void *key, const _Py_hashtable_entry_t *entry);
/* hash a pointer (void*) */
PyAPI_FUNC(Py_uhash_t) _Py_hashtable_hash_ptr(
size_t key_size,
const void *pkey);
/* comparison using memcmp() */
PyAPI_FUNC(int) _Py_hashtable_compare_direct(
size_t key_size,
const void *pkey,
const _Py_hashtable_entry_t *entry);
PyAPI_FUNC(_Py_hashtable_t *) _Py_hashtable_new(
size_t key_size,
size_t data_size,
_Py_hashtable_hash_func hash_func,
_Py_hashtable_compare_func compare_func);
PyAPI_FUNC(_Py_hashtable_t *) _Py_hashtable_new_full(
size_t key_size,
size_t data_size,
size_t init_size,
_Py_hashtable_hash_func hash_func,
@ -84,45 +123,95 @@ PyAPI_FUNC(_Py_hashtable_t *) _Py_hashtable_new_full(
_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(_Py_hashtable_t *) _Py_hashtable_copy(_Py_hashtable_t *src);
PyAPI_FUNC(void) _Py_hashtable_clear(_Py_hashtable_t *ht);
PyAPI_FUNC(void) _Py_hashtable_destroy(_Py_hashtable_t *ht);
typedef int (*_Py_hashtable_foreach_func) (_Py_hashtable_entry_t *entry, void *arg);
/* Return a copy of the hash table */
PyAPI_FUNC(_Py_hashtable_t *) _Py_hashtable_copy(_Py_hashtable_t *src);
PyAPI_FUNC(void) _Py_hashtable_clear(_Py_hashtable_t *ht);
typedef int (*_Py_hashtable_foreach_func) (_Py_hashtable_t *ht,
_Py_hashtable_entry_t *entry,
void *arg);
/* Call func() on each entry of the hashtable.
Iteration stops if func() result is non-zero, in this case it's the result
of the call. Otherwise, the function returns 0. */
PyAPI_FUNC(int) _Py_hashtable_foreach(
_Py_hashtable_t *ht,
_Py_hashtable_foreach_func func, void *arg);
_Py_hashtable_foreach_func func,
void *arg);
PyAPI_FUNC(size_t) _Py_hashtable_size(_Py_hashtable_t *ht);
PyAPI_FUNC(_Py_hashtable_entry_t*) _Py_hashtable_get_entry(
_Py_hashtable_t *ht,
const void *key);
/* Add a new entry to the hash. The key must not be present in the hash table.
Return 0 on success, -1 on memory error.
Don't call directly this function,
but use _Py_HASHTABLE_SET() and _Py_HASHTABLE_SET_NODATA() macros */
PyAPI_FUNC(int) _Py_hashtable_set(
_Py_hashtable_t *ht,
const void *key,
void *data,
size_t data_size);
PyAPI_FUNC(int) _Py_hashtable_get(
_Py_hashtable_t *ht,
const void *key,
void *data,
size_t data_size);
PyAPI_FUNC(int) _Py_hashtable_pop(
_Py_hashtable_t *ht,
const void *key,
void *data,
size_t data_size);
PyAPI_FUNC(void) _Py_hashtable_delete(
_Py_hashtable_t *ht,
const void *key);
size_t key_size,
const void *pkey,
size_t data_size,
void *data);
#define _Py_HASHTABLE_SET(TABLE, KEY, DATA) \
_Py_hashtable_set(TABLE, KEY, &(DATA), sizeof(DATA))
_Py_hashtable_set(TABLE, sizeof(KEY), &KEY, sizeof(DATA), &(DATA))
#define _Py_HASHTABLE_SET_NODATA(TABLE, KEY) \
_Py_hashtable_set(TABLE, sizeof(KEY), &KEY, 0, NULL)
/* Get an entry.
Return NULL if the key does not exist.
Don't call directly this function, but use _Py_HASHTABLE_GET_ENTRY()
macro */
PyAPI_FUNC(_Py_hashtable_entry_t*) _Py_hashtable_get_entry(
_Py_hashtable_t *ht,
size_t key_size,
const void *pkey);
#define _Py_HASHTABLE_GET_ENTRY(TABLE, KEY) \
_Py_hashtable_get_entry(TABLE, sizeof(KEY), &(KEY))
/* Get data from an entry. Copy entry data into data and return 1 if the entry
exists, return 0 if the entry does not exist.
Don't call directly this function, but use _Py_HASHTABLE_GET() macro */
PyAPI_FUNC(int) _Py_hashtable_get(
_Py_hashtable_t *ht,
size_t key_size,
const void *pkey,
size_t data_size,
void *data);
#define _Py_HASHTABLE_GET(TABLE, KEY, DATA) \
_Py_hashtable_get(TABLE, KEY, &(DATA), sizeof(DATA))
_Py_hashtable_get(TABLE, sizeof(KEY), &(KEY), sizeof(DATA), &(DATA))
/* Don't call directly this function, but use _Py_HASHTABLE_POP() macro */
PyAPI_FUNC(int) _Py_hashtable_pop(
_Py_hashtable_t *ht,
size_t key_size,
const void *pkey,
size_t data_size,
void *data);
#define _Py_HASHTABLE_POP(TABLE, KEY, DATA) \
_Py_hashtable_pop(TABLE, sizeof(KEY), &(KEY), sizeof(DATA), &(DATA))
/* Delete an entry.
WARNING: The entry must exist. */
PyAPI_FUNC(void) _Py_hashtable_delete(
_Py_hashtable_t *ht,
size_t key_size,
const void *pkey);
#endif /* Py_LIMITED_API */
#endif