Always use blosc2.nthreads as default value

src/blosc2/__init__.py

@@ -188,15 +188,23 @@ class Tuner(Enum):
     unpack_tensor,
 )
 
+# Internal Blosc threading
+# Get CPU info
+cpu_info = get_cpu_info()
+nthreads = ncores = cpu_info.get("count", 1)
+"""Number of threads to be used in compression/decompression.
+"""
+# Protection against too many threads
+nthreads = min(nthreads, 32)
+# Experiments say that, when using a large number of threads, it is better to not use them all
+nthreads -= nthreads // 8
+
 # This import must be before ndarray and schunk
 from .storage import (
     CParams,
     cparams_dflts,
-    cpu_info,
     DParams,
     dparams_dflts,
-    ncores,
-    nthreads,
     Storage,
     storage_dflts,
 )
@@ -254,13 +262,6 @@ class Tuner(Enum):
 The blosc2 version + date.
 """
 
-# Internal Blosc threading
-set_nthreads(nthreads)
-
-# Set the number of threads for NumExpr
-numexpr.set_num_threads(nthreads)
-
-_disable_overloaded_equal = False
 
 # Delayed imports for avoiding overwriting of python builtins
 from .ndarray import (

src/blosc2/blosc2_ext.pyx

@@ -726,7 +726,7 @@ cdef create_cparams_from_kwargs(blosc2_cparams *cparams, kwargs):
     cparams.clevel = kwargs.get('clevel', blosc2.cparams_dflts['clevel'])
     cparams.use_dict = kwargs.get('use_dict', blosc2.cparams_dflts['use_dict'])
     cparams.typesize = typesize = kwargs.get('typesize', blosc2.cparams_dflts['typesize'])
-    cparams.nthreads = kwargs.get('nthreads', blosc2.cparams_dflts['nthreads'])
+    cparams.nthreads = kwargs.get('nthreads', blosc2.nthreads)
     cparams.blocksize = kwargs.get('blocksize', blosc2.cparams_dflts['blocksize'])
     splitmode = kwargs.get('splitmode', blosc2.cparams_dflts['splitmode'])
     cparams.splitmode = splitmode.value
@@ -807,7 +807,7 @@ def compress2(src, **kwargs):
     return dest[:size]
 
 cdef create_dparams_from_kwargs(blosc2_dparams *dparams, kwargs, blosc2_cparams* cparams=NULL):
-    dparams.nthreads = kwargs.get('nthreads', blosc2.dparams_dflts['nthreads'])
+    dparams.nthreads = kwargs.get('nthreads', blosc2.nthreads)
     dparams.schunk = NULL
     dparams.postfilter = NULL
     dparams.postparams = NULL

src/blosc2/core.py

@@ -894,8 +894,9 @@ def set_nthreads(nthreads: int) -> int:
     --------
     :attr:`~blosc2.nthreads`
     """
+    rc = blosc2_ext.set_nthreads(nthreads)
     blosc2.nthreads = nthreads
-    return blosc2_ext.set_nthreads(nthreads)
+    return rc
 
 
 def compressor_list(plugins: bool = False) -> list:

src/blosc2/storage.py

@@ -11,20 +11,9 @@
 
 import blosc2
 
-# Internal Blosc threading
-# Get CPU info
-cpu_info = blosc2.get_cpu_info()
-nthreads = ncores = cpu_info.get("count", 1)
-"""Number of threads to be used in compression/decompression.
-"""
-# Protection against too many threads
-nthreads = min(nthreads, 32)
-# Experiments say that, when using a large number of threads, it is better to not use them all
-nthreads -= nthreads // 8
-
 
 def default_nthreads():
-    return nthreads
+    return blosc2.nthreads
 
 def default_filters():
     return [blosc2.Filter.NOFILTER,

tests/test_storage.py

@@ -98,15 +98,21 @@ def test_cparams_values(cparams):
 
     array = blosc2.empty((30, 30), np.int32, cparams=cparams)
     for field in fields(cparams_dataclass):
-        print(field.name)
         if field.name in ['filters', 'filters_meta']:
-            print(getattr(array.schunk.cparams, field.name))
             assert getattr(array.schunk.cparams, field.name)[:len(getattr(cparams_dataclass, field.name))] == getattr(cparams_dataclass, field.name)
         elif field.name == 'typesize':
             assert getattr(array.schunk.cparams, field.name) == array.dtype.itemsize
         elif field.name != 'blocksize':
             assert getattr(array.schunk.cparams, field.name) == getattr(cparams_dataclass, field.name)
 
+    blosc2.set_nthreads(10)
+    schunk = blosc2.SChunk(cparams=cparams)
+    cparams_dataclass = cparams if isinstance(cparams, blosc2.CParams) else blosc2.CParams(**cparams)
+    assert schunk.cparams.nthreads == cparams_dataclass.nthreads
+
+    array = blosc2.empty((30, 30), np.int32, cparams=cparams)
+    assert array.schunk.cparams.nthreads == cparams_dataclass.nthreads
+
 
 def test_cparams_defaults():
     cparams = blosc2.CParams()
@@ -122,6 +128,10 @@ def test_cparams_defaults():
     assert cparams.blocksize == 0
     assert cparams.tuner == blosc2.Tuner.STUNE
 
+    blosc2.set_nthreads(1)
+    cparams = blosc2.CParams()
+    assert cparams.nthreads == blosc2.nthreads
+
 
 def test_raises_cparams():
     cparams = blosc2.CParams(codec=blosc2.Codec.LZ4, clevel=6, typesize=4)
@@ -151,11 +161,21 @@ def test_dparams_values(dparams):
         assert getattr(schunk.dparams, field.name) == getattr(dparams_dataclass, field.name)
         assert getattr(array.schunk.dparams, field.name) == getattr(dparams_dataclass, field.name)
 
+    blosc2.set_nthreads(3)
+    schunk = blosc2.SChunk(dparams=dparams)
+    dparams_dataclass = dparams if isinstance(dparams, blosc2.DParams) else blosc2.DParams(**dparams)
+    array = blosc2.empty((30, 30), dparams=dparams)
+    assert schunk.dparams.nthreads == dparams_dataclass.nthreads
+    assert array.schunk.dparams.nthreads == dparams_dataclass.nthreads
 
 def test_dparams_defaults():
     dparams = blosc2.DParams()
     assert dparams.nthreads == blosc2.nthreads
 
+    blosc2.set_nthreads(1)
+    dparams = blosc2.DParams()
+    assert dparams.nthreads == blosc2.nthreads
+
 
 def test_raises_dparams():
     dparams = blosc2.DParams()