/* This contains internal definitions for python dictionaries,
 * mostly copied from cpython sourcecode.
 *
 * Moved here to make it easier to maintain in the face of python
 * changes.
 * */

#if PY_VERSION_HEX < 0x30b0000

/************************************************************/
/* Copied verbatim from cpython 3.8 (Objects/dict-common.h) */
/************************************************************/

#ifndef Py_DICT_COMMON_H
#define Py_DICT_COMMON_H

typedef struct {
    /* Cached hash code of me_key. */
    Py_hash_t me_hash;
    PyObject *me_key;
    PyObject *me_value; /* This field is only meaningful for combined tables */
} PyDictKeyEntry;

/* dict_lookup_func() returns index of entry which can be used like DK_ENTRIES(dk)[index].
 * -1 when no entry found, -3 when compare raises error.
 */
typedef Py_ssize_t (*dict_lookup_func)
    (PyDictObject *mp, PyObject *key, Py_hash_t hash, PyObject **value_addr);

#define DKIX_EMPTY (-1)
#define DKIX_DUMMY (-2)  /* Used internally */
#define DKIX_ERROR (-3)

/* 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. */
    Py_ssize_t dk_size;

    /* Function to lookup in the hash table (dk_indices):

       - lookdict(): general-purpose, and may return DKIX_ERROR if (and
         only if) a comparison raises an exception.

       - lookdict_unicode(): specialized to Unicode string keys, comparison of
         which can never raise an exception; that function can never return
         DKIX_ERROR.

       - lookdict_unicode_nodummy(): similar to lookdict_unicode() but further
         specialized for Unicode string keys that cannot be the <dummy> value.

       - lookdict_split(): Version of lookdict() for split tables. */
    dict_lookup_func dk_lookup;

    /* 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 dk_entries[dk_usable];" array follows:
       see the DK_ENTRIES() macro */
};

#endif


/***********************************************************/
/* Copied verbatim from cpython 3.8 (Objects/dictobject.c) */
/***********************************************************/

#define PERTURB_SHIFT 5
#define DK_SIZE(dk) ((dk)->dk_size)
#if SIZEOF_VOID_P > 4
#define DK_IXSIZE(dk)                          \
    (DK_SIZE(dk) <= 0xff ?                     \
        1 : DK_SIZE(dk) <= 0xffff ?            \
            2 : DK_SIZE(dk) <= 0xffffffff ?    \
                4 : sizeof(int64_t))
#else
#define DK_IXSIZE(dk)                          \
    (DK_SIZE(dk) <= 0xff ?                     \
        1 : DK_SIZE(dk) <= 0xffff ?            \
            2 : sizeof(int32_t))
#endif
#define DK_ENTRIES(dk) \
    ((PyDictKeyEntry*)(&((int8_t*)((dk)->dk_indices))[DK_SIZE(dk) * DK_IXSIZE(dk)]))

#define DK_MASK(dk) (((dk)->dk_size)-1)

/* lookup indices.  returns DKIX_EMPTY, DKIX_DUMMY, or ix >=0 */
static inline Py_ssize_t
dictkeys_get_index(PyDictKeysObject *keys, Py_ssize_t i)
{
    Py_ssize_t s = DK_SIZE(keys);
    Py_ssize_t ix;

    if (s <= 0xff) {
        int8_t *indices = (int8_t*)(keys->dk_indices);
        ix = indices[i];
    }
    else if (s <= 0xffff) {
        int16_t *indices = (int16_t*)(keys->dk_indices);
        ix = indices[i];
    }
#if SIZEOF_VOID_P > 4
    else if (s > 0xffffffff) {
        int64_t *indices = (int64_t*)(keys->dk_indices);
        ix = indices[i];
    }
#endif
    else {
        int32_t *indices = (int32_t*)(keys->dk_indices);
        ix = indices[i];
    }
    assert(ix >= DKIX_DUMMY);
    return ix;
}

/* write to indices. */
static inline void
dictkeys_set_index(PyDictKeysObject *keys, Py_ssize_t i, Py_ssize_t ix)
{
    Py_ssize_t s = DK_SIZE(keys);

    assert(ix >= DKIX_DUMMY);

    if (s <= 0xff) {
        int8_t *indices = (int8_t*)(keys->dk_indices);
        assert(ix <= 0x7f);
        indices[i] = (char)ix;
    }
    else if (s <= 0xffff) {
        int16_t *indices = (int16_t*)(keys->dk_indices);
        assert(ix <= 0x7fff);
        indices[i] = (int16_t)ix;
    }
#if SIZEOF_VOID_P > 4
    else if (s > 0xffffffff) {
        int64_t *indices = (int64_t*)(keys->dk_indices);
        indices[i] = ix;
    }
#endif
    else {
        int32_t *indices = (int32_t*)(keys->dk_indices);
        assert(ix <= 0x7fffffff);
        indices[i] = (int32_t)ix;
    }
}

/************************************************************/

#else   /* Python >= 3.11 */

#define Py_BUILD_CORE
#undef _PyGC_FINALIZED
#include <internal/pycore_dict.h>

/************************************************************/
/* Copied verbatim from cpython 3.11 (Objects/dictobject.c) */
/************************************************************/

#define PERTURB_SHIFT 5
#define DK_MASK(dk) (DK_SIZE(dk)-1)

/* lookup indices.  returns DKIX_EMPTY, DKIX_DUMMY, or ix >=0 */
static inline Py_ssize_t
dictkeys_get_index(const PyDictKeysObject *keys, Py_ssize_t i)
{
    int log2size = DK_LOG_SIZE(keys);
    Py_ssize_t ix;

    if (log2size < 8) {
        const int8_t *indices = (const int8_t*)(keys->dk_indices);
        ix = indices[i];
    }
    else if (log2size < 16) {
        const int16_t *indices = (const int16_t*)(keys->dk_indices);
        ix = indices[i];
    }
#if SIZEOF_VOID_P > 4
    else if (log2size >= 32) {
        const int64_t *indices = (const int64_t*)(keys->dk_indices);
        ix = indices[i];
    }
#endif
    else {
        const int32_t *indices = (const int32_t*)(keys->dk_indices);
        ix = indices[i];
    }
    assert(ix >= DKIX_DUMMY);
    return ix;
}

/* write to indices. */
static inline void
dictkeys_set_index(PyDictKeysObject *keys, Py_ssize_t i, Py_ssize_t ix)
{
    int log2size = DK_LOG_SIZE(keys);

    assert(ix >= DKIX_DUMMY);
    assert(keys->dk_version == 0);

    if (log2size < 8) {
        int8_t *indices = (int8_t*)(keys->dk_indices);
        assert(ix <= 0x7f);
        indices[i] = (char)ix;
    }
    else if (log2size < 16) {
        int16_t *indices = (int16_t*)(keys->dk_indices);
        assert(ix <= 0x7fff);
        indices[i] = (int16_t)ix;
    }
#if SIZEOF_VOID_P > 4
    else if (log2size >= 32) {
        int64_t *indices = (int64_t*)(keys->dk_indices);
        indices[i] = ix;
    }
#endif
    else {
        int32_t *indices = (int32_t*)(keys->dk_indices);
        assert(ix <= 0x7fffffff);
        indices[i] = (int32_t)ix;
    }
}

#endif
