Release GIL while (de)compressing

zstd/_bindings.pyx

@@ -9,7 +9,7 @@ cdef extern from "Python.h":
     void Py_DECREF(PyObject *o)
     PyObject *PyBytes_FromStringAndSize(char *v, Py_ssize_t len) except NULL
     int _PyBytes_Resize(PyObject **string, Py_ssize_t newsize) except -1
-    char *PyBytes_AS_STRING(PyObject *string)
+    char *PyBytes_AS_STRING(PyObject *string) nogil
 
 cdef extern from "zstd.h":
     # To simplify implementation, we use signed types (and detect errors with
@@ -20,9 +20,9 @@ cdef extern from "zstd.h":
     PY_LONG_LONG ZSTD_getFrameContentSize(const void *src, ssize_t srcSize)
     ssize_t      ZSTD_compress(void *dst, ssize_t dstCapacity,
                                const void *src, ssize_t srcSize,
-                               int compressionLevel)
+                               int compressionLevel) nogil
     ssize_t      ZSTD_decompress(void *dst, ssize_t dstCapacity,
-                                 const void *src, ssize_t compressedSize)
+                                 const void *src, ssize_t compressedSize) nogil
 
 def maxCLevel():
     return ZSTD_maxCLevel()
@@ -40,34 +40,39 @@ def getErrorName(code):
     # why can't I just cast to str ?
     IF str is bytes:
         return ZSTD_getErrorName(code)
-    return ZSTD_getErrorName(code).decode()
+    ELSE:
+        return ZSTD_getErrorName(code).decode()
 
-error = None
+global error
 
 def compress(bytes string not None, int level=0):
     cdef:
+        int x
         ssize_t srcSize = len(string)
         ssize_t dstCapacity = ZSTD_compressBound(srcSize)
         PyObject *dst = PyBytes_FromStringAndSize(NULL, dstCapacity)
-        int x = ZSTD_compress(PyBytes_AS_STRING(dst), dstCapacity,
-                              _PyBytes_AS_STRING(string), srcSize,
-                              level)
+    with nogil:
+        x = ZSTD_compress(PyBytes_AS_STRING(dst), dstCapacity,
+                          PyBytes_AS_STRING(<PyObject*>string), srcSize,
+                          level)
     if x < 0:
         Py_DECREF(dst)
         raise error(-x)
     _PyBytes_Resize(&dst, x)
     r = <object>dst
-    Py_DECREF(dst) # revert the unwanted incref on the previous line
+    Py_DECREF(<PyObject*>r) # revert the unwanted incref on the previous line
     return r
 
 def decompress(bytes string not None):
     cdef:
+        int x
         ssize_t compressedSize = len(string)
         void *src = _PyBytes_AS_STRING(string)
         PY_LONG_LONG dstCapacity = _getFrameContentSize(src, compressedSize)
     dst = _PyBytes_FromStringAndSize(NULL, dstCapacity)
-    cdef int x = ZSTD_decompress(_PyBytes_AS_STRING(dst), dstCapacity,
-                                 src, compressedSize)
+    with nogil:
+        x = ZSTD_decompress(PyBytes_AS_STRING(<PyObject*>dst), dstCapacity,
+                            src, compressedSize)
     if x < 0:
         raise error(-x)
     return dst