Python: bytearray body support for ASGI module.

@filiphanes requested support for bytearray
and memoryview in the request body here:
<https://github.com/nginx/unit/issues/648>

This patch implements bytearray body support only.
Memoryview body still need to be implemented.

docs/changes.xml

@@ -78,6 +78,12 @@ can be used as a unique request identifier.
 </para>
 </change>
 
+<change type="feature">
+<para>
+bytearray in response body for ASGI applications.
+</para>
+</change>
+
 <change type="feature">
 <para>
 ServerRequest.flushHeaders() implemented in Node.js module to make it compatible

src/python/nxt_python_asgi_http.c

@@ -362,16 +362,6 @@ nxt_py_asgi_http_response_body(nxt_py_asgi_http_t *http, PyObject *dict)
     Py_ssize_t              body_len, body_off;
     nxt_py_asgi_ctx_data_t  *ctx_data;
 
-    body = PyDict_GetItem(dict, nxt_py_body_str);
-    if (nxt_slow_path(body != NULL && !PyBytes_Check(body))) {
-        return PyErr_Format(PyExc_TypeError, "'body' is not a byte string");
-    }
-
-    more_body = PyDict_GetItem(dict, nxt_py_more_body_str);
-    if (nxt_slow_path(more_body != NULL && !PyBool_Check(more_body))) {
-        return PyErr_Format(PyExc_TypeError, "'more_body' is not a bool");
-    }
-
     if (nxt_slow_path(http->complete)) {
         return PyErr_Format(PyExc_RuntimeError,
                             "Unexpected ASGI message 'http.response.body' "
@@ -382,9 +372,26 @@ nxt_py_asgi_http_response_body(nxt_py_asgi_http_t *http, PyObject *dict)
         return PyErr_Format(PyExc_RuntimeError, "Concurrent send");
     }
 
+    more_body = PyDict_GetItem(dict, nxt_py_more_body_str);
+    if (nxt_slow_path(more_body != NULL && !PyBool_Check(more_body))) {
+        return PyErr_Format(PyExc_TypeError, "'more_body' is not a bool");
+    }
+
+    body = PyDict_GetItem(dict, nxt_py_body_str);
+
     if (body != NULL) {
-        body_str = PyBytes_AS_STRING(body);
-        body_len = PyBytes_GET_SIZE(body);
+        if (PyBytes_Check(body)) {
+            body_str = PyBytes_AS_STRING(body);
+            body_len = PyBytes_GET_SIZE(body);
+
+        } else if (PyByteArray_Check(body)) {
+            body_str = PyByteArray_AS_STRING(body);
+            body_len = PyByteArray_GET_SIZE(body);
+
+        } else {
+            return PyErr_Format(PyExc_TypeError,
+                                "'body' is not a byte string or bytearray");
+        }
 
         nxt_unit_req_debug(http->req, "asgi_http_response_body: %d, %d",
                            (int) body_len, (more_body == Py_True) );

test/python/body_bytearray/asgi.py

@@ -0,0 +1,20 @@
+async def application(scope, receive, send):
+    assert scope['type'] == 'http'
+
+    body = b''
+    while True:
+        m = await receive()
+        body += m.get('body', b'')
+        if not m.get('more_body', False):
+            body = bytearray(body)
+            break
+
+    await send(
+        {
+            'type': 'http.response.start',
+            'status': 200,
+            'headers': [(b'content-length', str(len(body)).encode())],
+        }
+    )
+
+    await send({'type': 'http.response.body', 'body': body})

test/test_asgi_application.py

@@ -218,6 +218,14 @@ def test_asgi_application_shm_ack_handle():
     assert resp['body'] == body, 'keep-alive 1'
 
 
+def test_asgi_application_body_bytearray():
+    client.load('body_bytearray')
+
+    body = '0123456789'
+
+    assert client.post(body=body)['body'] == body
+
+
 def test_asgi_keepalive_body():
     client.load('mirror')