WIP: pure python

.github/workflows/ci-linux.yaml

@@ -8,7 +8,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.6", "3.7", "3.8", "3.9"]
+        python-version: ["3.7", "3.8", "3.9"]
         os: [ubuntu-18.04, ubuntu-20.04]
 
     steps:
@@ -25,6 +25,7 @@ jobs:
       - name: Install numcodecs
         run: |
           python -m pip install -U pip -r requirements_test.txt -r requirements.txt
+          python -m pip install -U --only-binary blosc blosc
           python -m pip install -v -e .
 
       - name: List installed packages

.github/workflows/ci-osx.yaml

@@ -8,7 +8,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.6", "3.7", "3.8", "3.9"]
+        python-version: ["3.7", "3.8", "3.9"]
 
     steps:
       - name: Checkout source
@@ -31,6 +31,7 @@ jobs:
           conda activate env
           which pip
           pip install -r requirements_test.txt -r requirements.txt
+          pip install -U --only-binary blosc blosc
           conda env export
 
       - name: Install numcodecs

.github/workflows/ci-windows.yaml

@@ -8,7 +8,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.6", "3.7", "3.8", "3.9"]
+        python-version: ["3.7", "3.8", "3.9"]
 
     steps:
       - name: Checkout source
@@ -31,6 +31,7 @@ jobs:
           conda activate env
           which pip
           pip install -r requirements_test.txt -r requirements.txt
+          pip install -U --only-binary blosc blosc
           conda env export
 
       - name: Install numcodecs

.gitmodules

@@ -1,3 +0,0 @@
-[submodule "c-blosc"]
-	path = c-blosc
-	url = https://github.com/Blosc/c-blosc.git

numcodecs/__init__.py

@@ -40,18 +40,12 @@
     pass
 
 try:
+    import blosc as _blosc
     from numcodecs import blosc
     from numcodecs.blosc import Blosc
     register_codec(Blosc)
-    # initialize blosc
-    try:
-        ncores = multiprocessing.cpu_count()
-    except OSError:  # pragma: no cover
-        ncores = 1
-    blosc.init()
-    blosc.set_nthreads(min(8, ncores))
-    atexit.register(blosc.destroy)
 except ImportError:  # pragma: no cover
+    raise
     pass
 
 try:
@@ -66,6 +60,7 @@
     from numcodecs.lz4 import LZ4
     register_codec(LZ4)
 except ImportError:  # pragma: no cover
+    raise
     pass
 
 from numcodecs.astype import AsType