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Diffstat (limited to 'Cython/Includes/cpython/contextvars.pxd')
| -rw-r--r-- | Cython/Includes/cpython/contextvars.pxd | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/Cython/Includes/cpython/contextvars.pxd b/Cython/Includes/cpython/contextvars.pxd new file mode 100644 index 000000000..aa8002664 --- /dev/null +++ b/Cython/Includes/cpython/contextvars.pxd @@ -0,0 +1,140 @@ +from cpython.object cimport PyObject +from cpython.ref cimport Py_XDECREF + +cdef extern from "Python.h": + # Defining PyContextVar_Get() below to always return the default value for Py<3.7 and PyPy<7.3.6 + # to make the inline functions sort-of work. + """ + #if (PY_VERSION_HEX < 0x030700b1 || (CYTHON_COMPILING_IN_PYPY && PYPY_VERSION_NUM < 0x07030600)) && !defined(PyContextVar_Get) + #define PyContextVar_Get(var, d, v) \ + ((d) ? \ + ((void)(var), Py_INCREF(d), (v)[0] = (d), 0) : \ + ((v)[0] = NULL, 0) \ + ) + #endif + """ + + ############################################################################ + # Context Variables Objects + ############################################################################ + + # PyContext + # The C structure used to represent a `contextvars.Context` object. + + # PyContextVar + # The C structure used to represent a `contextvars.ContextVar` object. + + # PyContextToken + # The C structure used to represent a `contextvars.Token` object. + + # PyTypeObject PyContext_Type + # Type object representing the `contextvars.Context` type. + + # PyTypeObject PyContextVar_Type + # Type object representing the `contextvars.ContextVar` type. + + # PyTypeObject PyContextToken_Type + # Type object representing the `contextvars.Token` type. + + bint PyContext_CheckExact(object obj) + # Return `true` if `obj` is of type `PyContext_Type`. + # `obj` must not be NULL. This function always succeeds. + + bint PyContextVar_CheckExact(object obj) + # Return `true` if `obj` is of type `PyContextVar_Type`. + # `obj` must not be NULL. This function always succeeds. + + bint PyContextToken_CheckExact(object obj) + # Return `true` if `obj` is of type `PyContextToken_Type`. + # `obj` must not be NULL. This function always succeeds. + + object PyContext_New() + # Return value: New reference. + # Create a new empty context object. + # Returns NULL if an error has occurred. + + object PyContext_Copy(object ctx) + # Return value: New reference. + # Create a shallow copy of the passed `ctx` context object. + # Returns NULL if an error has occurred. + + object PyContext_CopyCurrent() + # Return value: New reference. + # Create a shallow copy of the current thread context. + # Returns NULL if an error has occurred. + + int PyContext_Enter(object ctx) except -1 + # Set `ctx` as the current context for the current thread. + # Returns 0 on success, and -1 on error. + + int PyContext_Exit(object ctx) except -1 + # Deactivate the `ctx` context and restore the previous context + # as the current context for the current thread. + # Returns 0 on success, and -1 on error. + + object PyContextVar_New(const char* name, PyObject* default_value) + # Return value: New reference. + # Create a new ContextVar object. The `name` parameter is used + # for introspection and debug purposes. The `default_value` parameter + # may optionally specify the default value for the context variable. + # If an error has occurred, this function returns NULL. + + object PyContextVar_New_with_default "PyContextVar_New" (const char* name, object default_value) + # A different declaration of PyContextVar_New that requires a default value + # to be passed on call. + + int PyContextVar_Get(object var, PyObject* default_value, PyObject** value) except -1 + # Get the value of a context variable. + # Returns -1 if an error has occurred during lookup, and 0 if no error + # occurred, whether or not a value was found. + # + # If the context variable was found, `value` will be a pointer to it. + # If the context variable was not found, `value` will point to: + # + # • `default_value`, if not NULL; + # • the default value of `var`, if not NULL; + # • NULL + int PyContextVar_Get_with_default "PyContextVar_Get" (object var, object default_value, PyObject** value) except -1 + # A different declaration of PyContextVar_Get that requires a default value + # to be passed on call. + + object PyContextVar_Set(object var, object value) + # Return value: New reference. + # Set the value of `var` to `value` in the current context. + # Returns a token object for this value change, or NULL if an error has occurred. + + int PyContextVar_Reset(object var, object token) except -1 + # Reset the state of the `var` context variable to that it was in + # before `PyContextVar_Set()` that returned `token` was called. + # This function returns 0 on success and -1 on error. + + +cdef inline object get_value(var, default_value=None): + """Return a new reference to the value of the context variable, + or the default value of the context variable, + or None if no such value or default was found. + """ + cdef PyObject *value = NULL + PyContextVar_Get(var, NULL, &value) + if value is NULL: + # context variable does not have a default + pyvalue = default_value + else: + # value or default value of context variable + pyvalue = <object>value + Py_XDECREF(value) # PyContextVar_Get() returned an owned reference as 'PyObject*' + return pyvalue + + +cdef inline object get_value_no_default(var, default_value=None): + """Return a new reference to the value of the context variable, + or the provided default value if no such value was found. + + Ignores the default value of the context variable, if any. + """ + cdef PyObject *value = NULL + PyContextVar_Get(var, <PyObject*>default_value, &value) + # value of context variable or 'default_value' + pyvalue = <object>value + Py_XDECREF(value) # PyContextVar_Get() returned an owned reference as 'PyObject*' + return pyvalue |