Documentation: PyDictKeysObjects layout diagram in the comments section of Objects/dictobjects.c file #115941
Description
Documentation
The PyDictKeysObjects layout diagram in the file Objects/dictobjects.c comments section, shown below:
layout:
+---------------------+
| dk_refcnt |
| dk_log2_size |
| dk_log2_index_bytes |
| dk_kind |
| dk_usable |
| dk_nentries |
+---------------------+
| dk_indices[] |
| |
+---------------------+
| dk_entries[] |
| |
+---------------------+
seems not to correspond with the actual definition of PyDictKeysObjects which is a typedef of _dictkeysobject, where _dictkeysobject is located in the file Include/internal/pycore_dict.h, and its structure is reproduced below:
/* See dictobject.c for actual layout of DictKeysObject */
struct _dictkeysobject {
Py_ssize_t dk_refcnt;
/* Size of the hash table (dk_indices). It must be a power of 2. */
uint8_t dk_log2_size;
/* Size of the hash table (dk_indices) by bytes. */
uint8_t dk_log2_index_bytes;
/* Kind of keys */
uint8_t dk_kind;
/* Version number -- Reset to 0 by any modification to keys */
uint32_t dk_version;
/* Number of usable entries in dk_entries. */
Py_ssize_t dk_usable;
/* Number of used entries in dk_entries. */
Py_ssize_t dk_nentries;
/* Actual hash table of dk_size entries. It holds indices in dk_entries,
or DKIX_EMPTY(-1) or DKIX_DUMMY(-2).
Indices must be: 0 <= indice < USABLE_FRACTION(dk_size).
The size in bytes of an indice depends on dk_size:
- 1 byte if dk_size <= 0xff (char*)
- 2 bytes if dk_size <= 0xffff (int16_t*)
- 4 bytes if dk_size <= 0xffffffff (int32_t*)
- 8 bytes otherwise (int64_t*)
Dynamically sized, SIZEOF_VOID_P is minimum. */
char dk_indices[]; /* char is required to avoid strict aliasing. */
/* "PyDictKeyEntry or PyDictUnicodeEntry dk_entries[USABLE_FRACTION(DK_SIZE(dk))];" array follows:
see the DK_ENTRIES() macro */
};The struct _dictkeysobject has a dk_version field and it doesn't contain a dk_entries field, whereas the layout diagram in the code comments' section shows such fields.
End.