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_sparsedict.c
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_sparsedict.c
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/* Hash table (dictionary) with low memory overhead.
Uses the same algorithms and data structures as the sparse_hash_map
from google-sparsehash (http://code.google.com/p/google-sparsehash/).
It's also very similar to (and borrows portions of code from) python's builtin dict.
*/
#include "Python.h"
#ifdef _MSC_VER
#pragma warning(disable : 4232) /* taking dllimport address */
#endif
/* Python versions compatibility */
#if PY_VERSION_HEX < 0x02060000
#define Py_TYPE(ob) (((PyObject*)(ob))->ob_type)
#define PyVarObject_HEAD_INIT(type, size) PyObject_HEAD_INIT(type) size,
#define PyBytesObject PyStringObject
#define PyBytes_AS_STRING PyString_AS_STRING
#define PyBytes_GET_SIZE PyString_GET_SIZE
#define PyBytes_CheckExact PyString_CheckExact
#define PyObject_HashNotImplemented 0
#endif
#if PY_VERSION_HEX < 0x02070000
/* XXX: this is totally private API */
#define _PyObject_GC_IS_TRACKED(o) \
((_Py_AS_GC(o))->gc.gc_refs != _PyGC_REFS_UNTRACKED)
#define _PyObject_GC_MAY_BE_TRACKED(obj) \
(PyObject_IS_GC(obj) && (!PyTuple_CheckExact(obj) || _PyObject_GC_IS_TRACKED(obj)))
#endif
#if PY_VERSION_HEX < 0x03020000
typedef long Py_hash_t;
#define PyArg_ValidateKeywordArguments(kwds) 1
#endif
#if PY_MAJOR_VERSION < 3
#define PyDict_GetItemWithError PyDict_GetItem
#else
#define PyInt_Check PyLong_Check
#define PyInt_FromLong PyLong_FromLong
#define PyInt_FromSize_t PyLong_FromSize_t
#define PyInt_FromSsize_t PyLong_FromSsize_t
#define PyInt_AsSsize_t PyLong_AsSsize_t
#define PyString_FromString PyUnicode_FromString
#define PyString_FromFormat PyUnicode_FromFormat
#define PyString_Concat PyUnicode_Append
#define _PyString_Join PyUnicode_Join
#define Py_TPFLAGS_CHECKTYPES 0
#endif
/* Behavioral constants */
#define SPARSEBLOCK_SIZE 48
#define INITIAL_ITEMS 32 /* Largest power of 2 that fits in one sparseblock. */
#ifdef COLLECT_EX_STATS
#define EX_STATS(stmt) stmt
#else
#define EX_STATS(stmt)
#endif
/* Single dictionary entry. */
typedef struct {
PyObject *key; /* NULL key signifies deleted entry */
PyObject *value;
} dictentry;
/* Sparse chunk of hash space holding SPARSEBLOCK_SIZE items.
Each item is allocated on demand, item allocation status is marked in the bitmap. */
typedef struct {
dictentry *items;
unsigned short num_items;
unsigned char bitmap[(SPARSEBLOCK_SIZE + 7) / 8];
} sparseblock;
typedef struct _sparsedictobject SparseDictObject;
struct _sparsedictobject {
PyObject_HEAD
dictentry *(*lookup)(SparseDictObject *self, PyObject *key, Py_hash_t hash, int insert);
Py_ssize_t num_blocks; /* Chunks of hash space by SPARSEBLOCK_SIZE items. */
Py_ssize_t num_items; /* Total number of alocated items in all blocks. */
Py_ssize_t num_deleted; /* Number of deleted items (allocated, but have NULL key). */
Py_ssize_t _max_items; /* Max items possible without resizing the blocks array. Lower bits hold the flags. */
Py_ssize_t next_index; /* Index in hash space to resume search for nondeleted items. Used by popitem. */
sparseblock *blocks;
sparseblock static_blocks[1]; /* Spare block to avoid allocations for "empty" state. */
EX_STATS(size_t total_collisions;)
EX_STATS(size_t total_resizes;)
};
/* Number of items is always a power of 2 >= INITIAL_ITEMS therefore
we have the lower bits available for flags. */
#define FLAG_CONSIDER_SHRINK 1 /* Set in dict_delete, cleared in dict_resize_delta. */
#define FLAG_DISABLE_RESIZE 2 /* Used in resize and equals. */
#define FLAGS_MASK 3
/* sparseblock methods */
#define BIT_TEST(bitmap, i) (bitmap[i / 8] & (1 << (i % 8)))
#define BIT_SET(bitmap, i) (bitmap[i / 8] |= (1 << (i % 8)))
#define BIT_RESET(bitmap, i) (bitmap[i / 8] &= ~(1 << (i % 8)))
/* 1-bit count (aka population count) in a byte. */
static const unsigned char popcnt8[256] = {
0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8,
};
/* Check that sparseblock is healthy. */
#define SPARSEBLOCK_INVARIANT(block, index) \
do { \
Py_ssize_t num_items = 0; \
assert(index >= 0 && index < SPARSEBLOCK_SIZE); \
assert((block) != NULL); \
assert((block)->num_items == 0 || (block)->items != NULL); \
assert((block)->num_items >= 0 && (block)->num_items <= SPARSEBLOCK_SIZE); \
for (i = 0; i < SPARSEBLOCK_SIZE / 8; ++i) \
num_items += popcnt8[(block)->bitmap[i]]; \
assert(num_items == (block)->num_items); \
} while (0)
/* Find the item at index. If the item is not allocated, return NULL. */
Py_LOCAL_INLINE(dictentry *)
sparseblock_find(sparseblock *block, Py_ssize_t index)
{
int i, offset = 0;
SPARSEBLOCK_INVARIANT(block, index);
if (!BIT_TEST(block->bitmap, index))
return NULL;
for (i = 0; index > 8; ++i, index -= 8)
offset += popcnt8[block->bitmap[i]];
offset += popcnt8[block->bitmap[i] & ((1 << index)-1)];
return &block->items[offset];
}
/* Allocate new item at the previously unallocated index. Returns NULL on failure. */
Py_LOCAL_INLINE(dictentry *)
sparseblock_insert(sparseblock *block, Py_ssize_t index)
{
int i, num_items, offset = 0;
dictentry *items;
SPARSEBLOCK_INVARIANT(block, index);
assert(!BIT_TEST(block->bitmap, index)); /* not allocated yet? */
assert(block->num_items < SPARSEBLOCK_SIZE); /* enough space for another element? */
items = block->items;
num_items = block->num_items + 1;
/* Realloc only every other insert */
if (num_items & 1) {
items = PyMem_RESIZE(items, dictentry, num_items + 1);
if (items == NULL) {
PyErr_NoMemory();
return NULL;
}
block->items = items;
}
block->num_items = (unsigned short) num_items;
BIT_SET(block->bitmap, index);
/* Count allocated nodes (bitmap bits) upto index. */
for (i = 0; index > 8; ++i, index -= 8)
offset += popcnt8[block->bitmap[i]];
offset += popcnt8[block->bitmap[i] & ((1 << index)-1)];
/* Shift to make place for new item. */
for (i = num_items - 1; i > offset; --i)
items[i] = items[i-1];
return &items[offset];
}
/* SparseDict macros */
PyTypeObject SparseDict_Type;
PyTypeObject SparseDictIterKey_Type;
PyTypeObject SparseDictIterValue_Type;
PyTypeObject SparseDictIterItem_Type;
PyTypeObject SparseDictKeys_Type;
PyTypeObject SparseDictValues_Type;
PyTypeObject SparseDictItems_Type;
#define SparseDict_Check(op) PyObject_TypeCheck(op, &SparseDict_Type)
#define SparseDict_CheckExact(op) (Py_TYPE(op) == &SparseDict_Type)
#define SparseDictViewSet_Check(op) \
(Py_TYPE(op) == &SparseDictKeys_Type || Py_TYPE(op) == &SparseDictItems_Type)
#define SparseDict_MAX_ITEMS(sdict) ((sdict)->_max_items & ~FLAGS_MASK)
#define SparseDict_SIZE(sdict) ((sdict)->num_items - (sdict)->num_deleted)
#define SparseDict_INIT_NONZERO(sdict) \
do { \
(sdict)->num_blocks = 1; \
(sdict)->_max_items = INITIAL_ITEMS; \
(sdict)->blocks = (sdict)->static_blocks; \
} while (0)
#define SparseDict_INIT(sdict) \
do { \
(sdict)->num_items = 0; \
(sdict)->num_deleted = 0; \
(sdict)->next_index = 0; \
EX_STATS((sdict)->total_collisions = 0); \
EX_STATS((sdict)->total_resizes = 0); \
memset((sdict)->static_blocks, 0, sizeof(sparseblock)); \
SparseDict_INIT_NONZERO(sdict); \
} while (0)
/* A bunch of asserts for basic SparseDictObject invariants. */
#define SparseDict_INVARIANT(sdict) \
do { \
assert((sdict) != NULL); \
assert(SparseDict_Check(sdict)); \
assert((sdict)->lookup != NULL); \
assert((sdict)->blocks != NULL); \
assert(SparseDict_MAX_ITEMS(sdict) >= INITIAL_ITEMS); \
assert((SparseDict_MAX_ITEMS(sdict) & (SparseDict_MAX_ITEMS(sdict) - 1)) == 0); /* power of 2 */ \
assert((sdict)->num_items <= SparseDict_MAX_ITEMS(sdict)); \
assert((sdict)->num_deleted <= (sdict)->num_items); \
} while (0)
/* Iterator over allocated items in all blocks. Cannot be nested. Do not use continue. */
#define SparseDict_FOR(sdict, entry) \
{ \
Py_ssize_t i__; \
int j__, num_items__; \
dictentry *items__, entry; \
for (i__ = 0; i__ < (sdict)->num_blocks; ++i__) { \
items__ = (sdict)->blocks[i__].items; \
num_items__ = (sdict)->blocks[i__].num_items; \
for (j__ = 0; j__ < num_items__; ++j__) { \
entry = items__[j__]; \
if (entry.key != NULL) {
#define SparseDict_ENDFOR(sdict, destructive) \
} \
} \
if (destructive) PyMem_FREE(items__); \
} \
if (destructive && ((sdict)->blocks != (sdict)->static_blocks)) \
PyMem_FREE((sdict)->blocks); \
}
/* Delay GC tracking until the first trackable item is inserted. */
#define MAINTAIN_TRACKING(sdict, key, value) \
do { \
if (!_PyObject_GC_IS_TRACKED(sdict)) \
if (_PyObject_GC_MAY_BE_TRACKED(key) || _PyObject_GC_MAY_BE_TRACKED(value)) \
PyObject_GC_Track(sdict); \
} while (0)
/* Forward */
static PyObject *dictiter_new(SparseDictObject *dict, PyTypeObject *type);
static PyObject *dictview_new(SparseDictObject *dict, PyTypeObject *type);
/* Dummy "deleted" entry used by dict_lookup to distinguish "not found" from error (NULL). */
static dictentry entry_not_found = {NULL, NULL};
/* SparseDict method helpers */
Py_LOCAL(int) dict_resize(SparseDictObject *self, Py_ssize_t new_max_items);
Py_LOCAL(int) dict_resize_delta(SparseDictObject *self, Py_ssize_t delta);
/* Integer hash based on PRNG. Used as a post-processing step for not so uniform Python's hashes. */
Py_LOCAL_INLINE(size_t)
hash_mix(Py_hash_t hash)
{
/* On 32-bit platforms, only lower 32 bits are used. */
return (size_t)(2862933555777941757ull * (unsigned PY_LONG_LONG)hash + 3037000493ul);
}
/* Same as _PyString_Equal but using the public API. */
Py_LOCAL_INLINE(int)
string_equal(PyObject *arg1, PyObject *arg2)
{
PyBytesObject *s1 = (PyBytesObject *)arg1;
PyBytesObject *s2 = (PyBytesObject *)arg2;
assert(PyBytes_CheckExact(arg1));
assert(PyBytes_CheckExact(arg2));
if (PyBytes_GET_SIZE(s1) != PyBytes_GET_SIZE(s2))
return 0;
if (PyBytes_AS_STRING(s1)[0] != PyBytes_AS_STRING(s2)[0])
return 0;
return memcmp(PyBytes_AS_STRING(s1),
PyBytes_AS_STRING(s2),
PyBytes_GET_SIZE(s1)) == 0;
}
/* Set a key error with the specified argument, wrapping it in a
* tuple automatically so that tuple keys are not unpacked as the
* exception arguments. */
Py_LOCAL_INLINE(void)
set_key_error(PyObject *arg)
{
PyObject *tuple;
tuple = PyTuple_Pack(1, arg);
if (!tuple)
return; /* caller will expect error to be set anyway */
PyErr_SetObject(PyExc_KeyError, tuple);
Py_DECREF(tuple);
}
/* Next nondeleted item search. Used in popitem() and iterators. */
Py_LOCAL_INLINE(dictentry *)
dict_next(SparseDictObject *self, Py_ssize_t *index, int wrap)
{
dictentry *entry = NULL;
int j = (int)*index & 0x3f;
Py_ssize_t i = *index >> 6;
do {
for (; i < self->num_blocks; ++i) {
int num_items = self->blocks[i].num_items;
dictentry *items = self->blocks[i].items;
for (; j < num_items; ++j) {
entry = &items[j];
if (entry->key != NULL)
goto Found;
}
j = 0;
}
i = 0;
} while (wrap);
Found:
*index = (i << 6) | (j+1);
return entry;
}
/* Search for an entry with the specified key.
If the key is not found and insert = 1, new entry is inserted and returned,
otherwise a dummy deleted entry is returned. if hash parameter is -1, it's recalculated
from the key. NULL return return means error. */
static dictentry *
dict_lookup(SparseDictObject *self, PyObject *key, Py_hash_t hash, int insert)
{
/* NULL key will make it look like deleted entry. */
size_t i, num_probes = 0;
size_t max_items_mask = (size_t)SparseDict_MAX_ITEMS(self) - 1;
dictentry *entry, *freeslot = NULL;
sparseblock *blocks = self->blocks;
int cmp;
PyObject *old_key;
if (hash == -1) {
if (PyBytes_CheckExact(key)) {
hash = ((PyBytesObject *)key)->ob_shash;
if (hash == -1)
hash = PyObject_Hash(key);
}
else {
hash = PyObject_Hash(key);
if (hash == -1)
return NULL;
}
}
i = hash_mix((size_t)hash) & max_items_mask;
for (;;) {
entry = sparseblock_find(&blocks[i / SPARSEBLOCK_SIZE], i % SPARSEBLOCK_SIZE);
if (entry == NULL) {
if (freeslot != NULL)
return freeslot;
if (!insert)
return &entry_not_found;
entry = sparseblock_insert(&blocks[i / SPARSEBLOCK_SIZE], i % SPARSEBLOCK_SIZE);
if (entry != NULL)
/* Mark as deleted to distinguish newly inserved from existing. */
entry->key = NULL;
return entry;
}
if (entry->key == key)
return entry;
if (entry->key != NULL) {
old_key = entry->key;
Py_INCREF(old_key);
cmp = PyObject_RichCompareBool(old_key, key, Py_EQ);
Py_DECREF(old_key);
if (cmp < 0)
return NULL;
if (self->blocks == blocks && entry->key == old_key) {
if (cmp > 0)
return entry;
}
else {
/* richcmp has changed the dict, restart */
return dict_lookup(self, key, hash, insert);
}
}
else if (freeslot == NULL)
/* entry->key == NULL, deleted entry */
freeslot = entry;
/* Quadratic probing */
++num_probes;
i = (i + num_probes) & max_items_mask;
EX_STATS(++self->total_collisions);
}
assert(0); /* NOT REACHED */
}
/* Special-case dict_lookup that assumes all keys in the dictionary are PyStringObjects. */
static dictentry *
dict_lookup_string(SparseDictObject *self, PyObject *key, Py_hash_t hash, int insert)
{
dictentry *entry, *freeslot = NULL;
sparseblock *blocks = self->blocks;
size_t i, num_probes = 0;
size_t max_items_mask = (size_t)SparseDict_MAX_ITEMS(self) - 1;
if (!PyBytes_CheckExact(key)) {
/* First non-string key, revert to universal lookup. */
self->lookup = dict_lookup;
return dict_lookup(self, key, hash, insert);
}
if (hash == -1) {
hash = ((PyBytesObject *)key)->ob_shash;
if (hash == -1)
hash = PyObject_Hash(key);
}
i = hash_mix((size_t)hash) & max_items_mask;
for (;;) {
entry = sparseblock_find(&blocks[i / SPARSEBLOCK_SIZE], i % SPARSEBLOCK_SIZE);
if (entry == NULL) {
if (freeslot != NULL)
return freeslot;
if (!insert)
return &entry_not_found;
entry = sparseblock_insert(&blocks[i / SPARSEBLOCK_SIZE], i % SPARSEBLOCK_SIZE);
if (entry != NULL)
entry->key = NULL;
return entry;
}
else if (entry->key == key || (entry->key != NULL && string_equal(entry->key, key)))
return entry;
else if (entry->key == NULL && freeslot == NULL)
/* Deleted entry */
freeslot = entry;
/* Quadratic probing */
++num_probes;
i = (i + num_probes) & max_items_mask;
EX_STATS(++self->total_collisions);
}
assert(0); /* NOT REACHED */
}
/* Insert an item into the dictionary. Same semantics as PyDict_SetItem. */
Py_LOCAL(int)
dict_insert(SparseDictObject *self, PyObject *key, PyObject *value)
{
PyObject *old_value;
dictentry *entry;
if (dict_resize_delta(self, 1) != 0)
return -1;
Py_INCREF(value);
Py_INCREF(key);
entry = (self->lookup)(self, key, -1, 1);
if (entry == NULL) {
Py_DECREF(key);
Py_DECREF(value);
return -1;
}
MAINTAIN_TRACKING(self, key, value);
if (entry->key != NULL) {
old_value = entry->value;
entry->value = value;
Py_DECREF(old_value); /* which **CAN** re-enter */
Py_DECREF(key);
}
else {
entry->key = key;
entry->value = value;
++self->num_items;
}
return 0;
}
/* Delete an item from the dictionary. Same semantics as PyDict_DelItem. */
Py_LOCAL(int)
dict_delete(SparseDictObject *self, PyObject *key)
{
dictentry *entry;
PyObject *old_key, *old_value;
entry = (self->lookup)(self, key, -1, 0);
if (entry == NULL)
return -1;
if (entry->key == NULL) {
set_key_error(key);
return -1;
}
old_key = entry->key;
old_value = entry->value;
entry->key = NULL;
++self->num_deleted;
self->_max_items |= FLAG_CONSIDER_SHRINK;
Py_DECREF(old_value);
Py_DECREF(old_key);
return 0;
}
/* This is caled to preallocate space for at least delta elements. */
Py_LOCAL(int)
dict_resize_delta(SparseDictObject *self, Py_ssize_t delta) {
/* Growth factor is 3/4 = 0.75, shrink factor is 5/16 = 0.3125 */
Py_ssize_t new_max_items = SparseDict_MAX_ITEMS(self);
if (delta <= 0)
return 0;
if (self->_max_items & FLAG_CONSIDER_SHRINK) {
self->_max_items &= ~FLAG_CONSIDER_SHRINK;
if (SparseDict_SIZE(self) < new_max_items * 5 / 16)
goto Resize;
}
if (self->num_items + delta <= new_max_items * 3 / 4)
return 0;
Resize:
/* Find the size which fits nondeleted items below enlarge threshold. */
new_max_items = INITIAL_ITEMS;
while (SparseDict_SIZE(self) + delta > new_max_items * 3 / 4)
new_max_items *= 2;
if (new_max_items < SparseDict_MAX_ITEMS(self)) {
/* We're actually shrinking due to lots of deleted elements. Try to re-grow. */
if (SparseDict_SIZE(self) + delta >= new_max_items * 2 * 5 / 16)
/* Doubling the size won't hit shrink limit. */
new_max_items *= 2;
}
return dict_resize(self, new_max_items);
}
/* Resize the hashtable by allocating a new sparseblock array and reinserting
all non-deleted items. Returns 0 on success, -1 on error. */
Py_LOCAL(int)
dict_resize(SparseDictObject *self, Py_ssize_t new_max_items)
{
Py_ssize_t max_items_mask = new_max_items - 1;
Py_ssize_t num_new_blocks = (new_max_items + SPARSEBLOCK_SIZE - 1) / SPARSEBLOCK_SIZE;
sparseblock *new_blocks;
Py_ssize_t i;
SparseDict_INVARIANT(self);
if (self->_max_items & FLAG_DISABLE_RESIZE) {
PyErr_SetString(PyExc_RuntimeError, "SparseDict: resize is not reentrant");
return -1;
}
self->_max_items |= FLAG_DISABLE_RESIZE;
new_blocks = PyMem_NEW(sparseblock, num_new_blocks);
if (new_blocks == NULL) {
PyErr_NoMemory();
return -1;
}
memset(new_blocks, 0, num_new_blocks * sizeof(sparseblock));
SparseDict_FOR(self, entry)
dictentry *new_entry;
Py_hash_t hash;
size_t i, num_probes = 0;
PyObject *key = entry.key;
if (PyBytes_CheckExact(key)) {
hash = ((PyBytesObject *)key)->ob_shash;
if (hash == -1)
hash = PyObject_Hash(key);
}
else {
hash = PyObject_Hash(key);
if (hash == -1)
goto Failed;
}
i = hash_mix((size_t)hash) & max_items_mask;
while (BIT_TEST(new_blocks[i / SPARSEBLOCK_SIZE].bitmap, i % SPARSEBLOCK_SIZE)) {
++num_probes;
i = (i + num_probes) & max_items_mask;
}
new_entry = sparseblock_insert(&new_blocks[i / SPARSEBLOCK_SIZE], i % SPARSEBLOCK_SIZE);
if (new_entry == NULL)
goto Failed;
*new_entry = entry;
/* Note: we do not use destructive iteration here. It has minimal impact on
memory usage during the resize but allows easy recover from hash and memory errors. */
SparseDict_ENDFOR(self, 0)
/* Free old blocks. */
for (i = 0; i < self->num_blocks; ++i)
PyMem_FREE(self->blocks[i].items);
if (self->blocks != self->static_blocks)
PyMem_FREE(self->blocks);
/* Update self with new blocks. */
if (num_new_blocks == 1) {
self->static_blocks[0] = new_blocks[0];
self->blocks = self->static_blocks;
PyMem_FREE(new_blocks);
}
else {
self->blocks = new_blocks;
}
self->_max_items = new_max_items; /* All flags are cleared */
self->num_blocks = num_new_blocks;
self->num_items -= self->num_deleted;
self->num_deleted = 0;
EX_STATS(++self->total_resizes);
SparseDict_INVARIANT(self);
return 0;
Failed:
/* Discard partial new_blocks. */
for (i = 0; i < num_new_blocks; ++i)
PyMem_FREE(new_blocks[i].items);
if (new_blocks != self->blocks)
PyMem_FREE(new_blocks);
return -1;
}
Py_LOCAL(int)
dict_merge_seq2(SparseDictObject *self, PyObject *seq2)
{
PyObject *it; /* iter(seq2) */
Py_ssize_t i; /* index into seq2 of current element */
PyObject *item; /* seq2[i] */
PyObject *fast; /* item as a 2-tuple or 2-list */
SparseDict_INVARIANT(self);
assert(seq2 != NULL);
it = PyObject_GetIter(seq2);
if (it == NULL)
return -1;
for (i = 0; ; ++i) {
PyObject *key, *value;
Py_ssize_t n;
fast = NULL;
item = PyIter_Next(it);
if (item == NULL) {
if (PyErr_Occurred())
goto Fail;
break;
}
/* Convert item to sequence, and verify length 2. */
fast = PySequence_Fast(item, "");
if (fast == NULL) {
if (PyErr_ExceptionMatches(PyExc_TypeError))
PyErr_Format(PyExc_TypeError,
"cannot convert dictionary update sequence element #%zd to a sequence",
i);
goto Fail;
}
n = PySequence_Fast_GET_SIZE(fast);
if (n != 2) {
PyErr_Format(PyExc_ValueError,
"dictionary update sequence element #%zd has length %zd; 2 is required",
i, n);
goto Fail;
}
/* Update/merge with this (key, value) pair. */
key = PySequence_Fast_GET_ITEM(fast, 0);
value = PySequence_Fast_GET_ITEM(fast, 1);
if (dict_insert(self, key, value) < 0)
goto Fail;
Py_DECREF(fast);
Py_DECREF(item);
}
i = 0;
goto Return;
Fail:
Py_XDECREF(item);
Py_XDECREF(fast);
i = -1;
Return:
Py_DECREF(it);
return Py_SAFE_DOWNCAST(i, Py_ssize_t, int);
}
Py_LOCAL(int)
dict_merge(SparseDictObject *self, PyObject *arg)
{
SparseDict_INVARIANT(self);
if (SparseDict_Check(arg)) {
SparseDictObject *other = (SparseDictObject *)arg;
if (other == self || SparseDict_SIZE(other) == 0)
return 0;
if (dict_resize_delta(self, SparseDict_SIZE(other) - SparseDict_SIZE(self)) != 0)
return -1;
SparseDict_FOR(other, entry)
Py_INCREF(entry.key);
Py_INCREF(entry.value);
if (dict_insert(self, entry.key, entry.value) != 0)
return -1;
SparseDict_ENDFOR(other, 0)
}
else if (PyDict_Check(arg)) {
Py_ssize_t other_size = PyDict_Size(arg);
Py_ssize_t pos = 0;
PyObject *key, *value;
if (other_size == 0)
return 0;
if (dict_resize_delta(self, other_size - SparseDict_SIZE(self)) != 0)
return -1;
while (PyDict_Next(arg, &pos, &key, &value)) {
Py_INCREF(key);
Py_INCREF(value);
if (dict_insert(self, key, value) != 0)
return -1;
}
}
else {
/* Do it the generic, slower way */
PyObject *keys = PyMapping_Keys(arg);
PyObject *iter;
PyObject *key, *value;
int status;
if (keys == NULL)
return -1;
iter = PyObject_GetIter(keys);
Py_DECREF(keys);
if (iter == NULL)
return -1;
while ((key = PyIter_Next(iter)) != NULL) {
value = PyObject_GetItem(arg, key);
if (value == NULL) {
Py_DECREF(iter);
Py_DECREF(key);
return -1;
}
status = dict_insert(self, key, value);
Py_DECREF(key);
Py_DECREF(value);
if (status < 0) {
Py_DECREF(iter);
return -1;
}
}
Py_DECREF(iter);
if (PyErr_Occurred())
/* Iterator completed, via error */
return -1;
}
return 0;
}
Py_LOCAL_INLINE(int)
dict_update_common(SparseDictObject *self, PyObject *args, PyObject *kwds, char *methname)
{
PyObject *arg = NULL;
int result = 0;
/* args == NULL means they were consubed by the caller */
if (args != NULL && !PyArg_UnpackTuple(args, methname, 0, 1, &arg))
return -1;
if (arg != NULL) {
if (PyObject_HasAttrString(arg, "keys"))
result = dict_merge(self, arg);
else
result = dict_merge_seq2(self, arg);
}
if (result == 0 && kwds != NULL) {
if (PyArg_ValidateKeywordArguments(kwds))
result = dict_merge(self, kwds);
else
result = -1;
}
return result;
}
/* Return 1 if dicts equal, 0 if not, -1 if error.
* Gets out as soon as any difference is detected.
* Uses only Py_EQ comparison.
*/
Py_LOCAL(int)
dict_equal(SparseDictObject *self, PyObject *arg)
{
SparseDictObject *other = NULL;
int result = 1;
SparseDict_INVARIANT(self);
if (SparseDict_Check(arg)) {
other = (SparseDictObject *)arg;
if (SparseDict_SIZE(self) != SparseDict_SIZE(other))
return 0;
}
else if (PyDict_Check(arg)) {
if (SparseDict_SIZE(self) != PyDict_Size(arg))
return 0;
}
else {
/* Unsupported type. */
return 0;
}
self->_max_items |= FLAG_DISABLE_RESIZE;
SparseDict_FOR(self, entry)
PyObject *key = entry.key;
PyObject *value = entry.value;
PyObject *value2;
Py_INCREF(key);
Py_INCREF(value);
if (other != NULL) {
/* comparing with another SparseDict */
dictentry *entry2 = (other->lookup)(other, key, -1, 0);
Py_DECREF(key);
if (entry2 == NULL || entry2->key == NULL) {
Py_DECREF(value);
result = (entry2 == NULL) ? -1 : 0;
break;
}
value2 = entry2->value;
}
else {
/* comparing with PyDictObject */
value2 = PyDict_GetItemWithError(arg, key);
Py_DECREF(key);
if (value2 == NULL) {
Py_DECREF(value);
result = PyErr_Occurred() ? -1 : 0;
break;
}
}
result = PyObject_RichCompareBool(value, value2, Py_EQ);
Py_DECREF(value);
if (result <= 0) /* error or not equal */
break;
SparseDict_ENDFOR(self, 0)
self->_max_items &= ~FLAG_DISABLE_RESIZE;
return result;
}
/* SparseDict type methods */
static SparseDictObject *
dict_tp_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
SparseDictObject *self;
self = (SparseDictObject *)type->tp_alloc(type, 0);
if (self != NULL) {
/* tp_alloc zero-initialized out struct */
SparseDict_INIT_NONZERO(self);
self->lookup = dict_lookup_string;
/* The object has been implicitely tracked by tp_alloc */
if (type == &SparseDict_Type)
PyObject_GC_UnTrack(self);
}
return self;
}
static int
dict_tp_init(SparseDictObject *self, PyObject *args, PyObject *kwds)
{
if (PyTuple_CheckExact(args) &&
PyTuple_GET_SIZE(args) == 1 &&
PyInt_Check(PyTuple_GET_ITEM(args, 0))) {
Py_ssize_t size_hint = PyInt_AsSsize_t(PyTuple_GET_ITEM(args, 0));
if (size_hint == -1 && PyErr_Occurred())
return -1;
if (dict_resize_delta(self, size_hint) != 0)
return -1;
args = NULL; /* do not pass args to dict_update_common */
}
return dict_update_common(self, args, kwds, "SparseDict");
}
static void
dict_tp_dealloc(SparseDictObject *self)
{
SparseDict_INVARIANT(self);
if (_PyObject_GC_IS_TRACKED(self))
PyObject_GC_UnTrack(self);
/* XXX: Py_TRASHCAN_SAFE_BEGIN ? */
/* with refcnt of 0 we don't need to protect from modifications. */
SparseDict_FOR(self, entry)
Py_DECREF(entry.key);
Py_DECREF(entry.value);
/* destructive FOR frees the blocks for us */
SparseDict_ENDFOR(self, 1)
Py_TYPE(self)->tp_free((PyObject *)self);
}
static PyObject *
dict_tp_repr(SparseDictObject *self)
{
Py_ssize_t i;
PyObject *s, *temp, *colon = NULL;
PyObject *pieces = NULL, *result = NULL;
i = Py_ReprEnter((PyObject *)self);
if (i != 0)
return i > 0 ? PyString_FromString("SparseDict(...)") : NULL;
if (SparseDict_SIZE(self) == 0) {
result = PyString_FromString("SparseDict()");
goto Done;
}
pieces = PyList_New(0);
if (pieces == NULL)
goto Done;
colon = PyString_FromString(": ");
if (colon == NULL)
goto Done;
/* Do repr() on each key+value pair, and insert ": " between them.
Note that repr may mutate the dict. */
SparseDict_FOR(self, entry)
int status;
/* Prevent repr from deleting value during key format. */
Py_INCREF(entry.value);
s = PyObject_Repr(entry.key);
PyString_Concat(&s, colon);
temp = PyObject_Repr(entry.value);
PyString_Concat(&s, temp);
Py_XDECREF(temp);
Py_DECREF(entry.value);
if (s == NULL)
goto Done;
status = PyList_Append(pieces, s);
Py_DECREF(s); /* append created a new ref */
if (status < 0)
goto Done;
SparseDict_ENDFOR(self, 0)
/* Add "{}" decorations to the first and last items. */
assert(PyList_GET_SIZE(pieces) > 0);
s = PyString_FromString("SparseDict({");
if (s == NULL)
goto Done;
temp = PyList_GET_ITEM(pieces, 0);
PyString_Concat(&s, temp);
Py_XDECREF(temp);
PyList_SET_ITEM(pieces, 0, s);
if (s == NULL)
goto Done;
s = PyString_FromString("})");
if (s == NULL)
goto Done;
temp = PyList_GET_ITEM(pieces, PyList_GET_SIZE(pieces) - 1);
PyString_Concat(&temp, s);
Py_XDECREF(s);
PyList_SET_ITEM(pieces, PyList_GET_SIZE(pieces) - 1, temp);