adds wrapper codecs for the v2 codec pipeline

Author: normanrz

numcodecs/tests/test_zstd.py

@@ -86,3 +86,10 @@ def test_checksum():
     assert len(Zstd(level=0, checksum=False).encode(data)) + 4 == len(
         Zstd(level=0, checksum=True).encode(data)
     )
+
+
+def test_native_functions():
+    # Note, these assertions might need to be changed for new versions of zstd
+    assert Zstd.default_level == 3
+    assert Zstd.min_level == -131072
+    assert Zstd.max_level == 22

numcodecs/zstd.pyx

@@ -48,7 +48,9 @@ cdef extern from "zstd.h":
     unsigned long long ZSTD_getFrameContentSize(const void* src,
                                                 size_t srcSize) nogil
 
+    int ZSTD_minCLevel() nogil
     int ZSTD_maxCLevel() nogil
+    int ZSTD_defaultCLevel() nogil
 
     size_t ZSTD_compressBound(size_t srcSize) nogil
 
@@ -255,3 +257,18 @@ class Zstd(Codec):
             (type(self).__name__,
              self.level)
         return r
+
+    @classmethod
+    @property
+    def default_level(cls):
+        return ZSTD_defaultCLevel()
+
+    @classmethod
+    @property
+    def min_level(cls):
+        return ZSTD_minCLevel()
+
+    @classmethod
+    @property
+    def max_level(cls):
+        return ZSTD_maxCLevel()