reconnect moved files to git repo

venv/lib/python3.11/site-packages/sklearn/utils/murmurhash.pyx

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+"""Cython wrapper for MurmurHash3 non-cryptographic hash function.
+
+MurmurHash is an extensively tested and very fast hash function that has
+good distribution properties suitable for machine learning use cases
+such as feature hashing and random projections.
+
+The original C++ code by Austin Appleby is released the public domain
+and can be found here:
+
+  https://code.google.com/p/smhasher/
+
+"""
+# Author: Olivier Grisel <olivier.grisel@ensta.org>
+#
+# License: BSD 3 clause
+
+from ..utils._typedefs cimport int32_t, uint32_t
+
+import numpy as np
+
+cdef extern from "src/MurmurHash3.h":
+    void MurmurHash3_x86_32(void *key, int len, uint32_t seed, void *out)
+    void MurmurHash3_x86_128(void *key, int len, uint32_t seed, void *out)
+    void MurmurHash3_x64_128 (void *key, int len, uint32_t seed, void *out)
+
+
+cpdef uint32_t murmurhash3_int_u32(int key, unsigned int seed):
+    """Compute the 32bit murmurhash3 of a int key at seed."""
+    cdef uint32_t out
+    MurmurHash3_x86_32(&key, sizeof(int), seed, &out)
+    return out
+
+
+cpdef int32_t murmurhash3_int_s32(int key, unsigned int seed):
+    """Compute the 32bit murmurhash3 of a int key at seed."""
+    cdef int32_t out
+    MurmurHash3_x86_32(&key, sizeof(int), seed, &out)
+    return out
+
+
+cpdef uint32_t murmurhash3_bytes_u32(bytes key, unsigned int seed):
+    """Compute the 32bit murmurhash3 of a bytes key at seed."""
+    cdef uint32_t out
+    MurmurHash3_x86_32(<char*> key, len(key), seed, &out)
+    return out
+
+
+cpdef int32_t murmurhash3_bytes_s32(bytes key, unsigned int seed):
+    """Compute the 32bit murmurhash3 of a bytes key at seed."""
+    cdef int32_t out
+    MurmurHash3_x86_32(<char*> key, len(key), seed, &out)
+    return out
+
+
+def _murmurhash3_bytes_array_u32(
+    const int32_t[:] key,
+    unsigned int seed,
+):
+    """Compute 32bit murmurhash3 hashes of a key int array at seed."""
+    # TODO make it possible to pass preallocated output array
+    cdef:
+        uint32_t[:] out = np.zeros(key.size, np.uint32)
+        Py_ssize_t i
+    for i in range(key.shape[0]):
+        out[i] = murmurhash3_int_u32(key[i], seed)
+    return np.asarray(out)
+
+
+def _murmurhash3_bytes_array_s32(
+    const int32_t[:] key,
+    unsigned int seed,
+):
+    """Compute 32bit murmurhash3 hashes of a key int array at seed."""
+    # TODO make it possible to pass preallocated output array
+    cdef:
+        int32_t[:] out = np.zeros(key.size, np.int32)
+        Py_ssize_t i
+    for i in range(key.shape[0]):
+        out[i] = murmurhash3_int_s32(key[i], seed)
+    return np.asarray(out)
+
+
+def murmurhash3_32(key, seed=0, positive=False):
+    """Compute the 32bit murmurhash3 of key at seed.
+
+    The underlying implementation is MurmurHash3_x86_32 generating low
+    latency 32bits hash suitable for implementing lookup tables, Bloom
+    filters, count min sketch or feature hashing.
+
+    Parameters
+    ----------
+    key : np.int32, bytes, unicode or ndarray of dtype=np.int32
+        The physical object to hash.
+
+    seed : int, default=0
+        Integer seed for the hashing algorithm.
+
+    positive : bool, default=False
+        True: the results is casted to an unsigned int
+          from 0 to 2 ** 32 - 1
+        False: the results is casted to a signed int
+          from -(2 ** 31) to 2 ** 31 - 1
+
+    Examples
+    --------
+    >>> from sklearn.utils import murmurhash3_32
+    >>> murmurhash3_32(b"Hello World!", seed=42)
+    3565178
+    """
+    if isinstance(key, bytes):
+        if positive:
+            return murmurhash3_bytes_u32(key, seed)
+        else:
+            return murmurhash3_bytes_s32(key, seed)
+    elif isinstance(key, unicode):
+        if positive:
+            return murmurhash3_bytes_u32(key.encode('utf-8'), seed)
+        else:
+            return murmurhash3_bytes_s32(key.encode('utf-8'), seed)
+    elif isinstance(key, int) or isinstance(key, np.int32):
+        if positive:
+            return murmurhash3_int_u32(<int32_t>key, seed)
+        else:
+            return murmurhash3_int_s32(<int32_t>key, seed)
+    elif isinstance(key, np.ndarray):
+        if key.dtype != np.int32:
+            raise TypeError(
+                "key.dtype should be int32, got %s" % key.dtype)
+        if positive:
+            return _murmurhash3_bytes_array_u32(key.ravel(), seed).reshape(key.shape)
+        else:
+            return _murmurhash3_bytes_array_s32(key.ravel(), seed).reshape(key.shape)
+    else:
+        raise TypeError(
+            "key %r with type %s is not supported. "
+            "Explicit conversion to bytes is required" % (key, type(key)))