Move java api to extras/

[vpp.git] / extras / japi / java / jvpp / gen / jvppgen / jni_impl_gen.py

diff --git a/extras/japi/java/jvpp/gen/jvppgen/jni_impl_gen.py b/extras/japi/java/jvpp/gen/jvppgen/jni_impl_gen.py
new file mode 100755 (executable)
index 0000000..bf75236
--- /dev/null
+++ b/extras/japi/java/jvpp/gen/jvppgen/jni_impl_gen.py
@@ -0,0 +1,115 @@
+#!/usr/bin/env python2
+#
+# Copyright (c) 2018 Cisco and/or its affiliates.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+from string import Template
+
+from jni_common_gen import generate_j2c_identifiers, generate_j2c_swap
+from jvpp_model import is_dump, is_request, is_control_ping, is_control_ping_reply
+
+
+def generate_jni_impl(model):
+    """
+    Generates JNI bindings for sending dump and request messages.
+    :param model: meta-model of VPP API used for jVPP generation.
+    """
+    jni_impl = []
+    for msg in model.messages:
+        if is_control_ping(msg) or is_control_ping_reply(msg):
+            # Skip control ping managed by jvpp registry.
+            continue
+        if not (is_dump(msg) or is_request(msg)):
+            continue
+        arguments = ""
+        request_class = ""
+        jni_identifiers = ""
+        msg_initialization = ""
+
+        if msg.has_fields:
+            arguments = ", jobject request"
+            request_class = _REQUEST_CLASS_TEMPLATE.substitute(
+                plugin_name=model.plugin_name,
+                java_dto_name=msg.java_name_upper
+            )
+            jni_identifiers = generate_j2c_identifiers(msg, class_ref_name="requestClass", object_ref_name="request")
+            msg_initialization = generate_j2c_swap(msg, struct_ref_name="mp")
+
+        jni_impl.append(_JNI_IMPL_TEMPLATE.substitute(
+            c_name=msg.name,
+            json_filename=model.json_api_files,
+            json_definition=msg.doc,
+            plugin_name=model.plugin_name,
+            plugin_java_name=model.plugin_java_name,
+            java_method_name=msg.java_name_lower,
+            arguments=arguments,
+            request_class=request_class,
+            jni_identifiers=jni_identifiers,
+            msg_size=_generate_msg_size(msg),
+            crc=msg.crc,
+            msg_initialization=msg_initialization
+        ))
+    return "".join(jni_impl)
+
+
+_JNI_IMPL_TEMPLATE = Template("""
+/**
+ * JNI binding for sending ${c_name} message.
+ * Generated based on $json_filename:
+$json_definition
+ */
+JNIEXPORT jint JNICALL Java_io_fd_vpp_jvpp_${plugin_name}_JVpp${plugin_java_name}Impl_${java_method_name}0
+(JNIEnv * env, jclass clazz${arguments}) {
+    ${plugin_name}_main_t *plugin_main = &${plugin_name}_main;
+    vl_api_${c_name}_t * mp;
+    u32 my_context_id = vppjni_get_context_id (&jvpp_main);
+$request_class
+$jni_identifiers
+
+    // create message:
+    const size_t _size = ${msg_size};
+    mp = vl_msg_api_alloc(_size);
+    memset (mp, 0, _size);
+    mp->_vl_msg_id = ntohs (get_message_id(env, "${c_name}_${crc}"));
+    mp->client_index = plugin_main->my_client_index;
+    mp->context = clib_host_to_net_u32 (my_context_id);
+
+$msg_initialization
+
+    // send message:
+    if (CLIB_DEBUG > 1)
+        clib_warning ("Sending ${c_name} message");
+    vl_msg_api_send_shmem (plugin_main->vl_input_queue, (u8 *)&mp);
+    if ((*env)->ExceptionCheck(env)) {
+        return JNI_ERR;
+    }
+    return my_context_id;
+}""")
+
+# TODO: cache method and field identifiers to achieve better performance
+# https://jira.fd.io/browse/HONEYCOMB-42
+_REQUEST_CLASS_TEMPLATE = Template("""    jclass requestClass = (*env)->FindClass(env, "io/fd/vpp/jvpp/${plugin_name}/dto/${java_dto_name}");
+""")
+
+
+def _generate_msg_size(msg):
+    msg_size = "sizeof(*mp)"
+    _size_components = []
+    for field in msg.fields:
+        # Ignore ZLAs for simplicity (to support them we need to call JNI functions to check actual size)
+        if field.array_len_field:
+            _size_components += " + %s*sizeof(%s)" % (field.array_len_field.java_name, field.type.base_type.vpp_name)
+            # FIXME(VPP-586): for proper nested structures support, we need generate functions computing type sizes
+            # and use it instead of sizeof
+
+    return msg_size + "".join(_size_components)