experiments with converting yang to protobuf with limited types
Change-Id: Icae31cbd779ff6f1efb6b5259e749436a7ee9bbf
diff --git a/experiments/plugin/protobuf.py b/experiments/plugin/protobuf.py
new file mode 100644
index 0000000..433ae30
--- /dev/null
+++ b/experiments/plugin/protobuf.py
@@ -0,0 +1,219 @@
+#!/usr/bin/env python
+#
+# Copyright 2016 the original author or authors.
+#
+# 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.
+#
+
+"""pyang plugin to convert a yang schema to a protobuf schema
+
+ - very basic support for leaf, leaf-list, containers, list
+
+"""
+
+from pyang import plugin, statements, error
+from pyang.util import unique_prefixes
+
+# Register the Protobuf plugin
+def pyang_plugin_init():
+ plugin.register_plugin(ProtobufPlugin())
+
+
+class Protobuf():
+ def __init__(self):
+ self.tree = {}
+ self.containers = []
+ self.ylist = []
+ self.messages = []
+ self.enums = []
+ self.headers = []
+ self.services = []
+ self.rpcs = []
+
+ def set_headers(self, module_name):
+ self.headers.append('syntax = "proto3";')
+ self.headers.append('package {};'.format(module_name))
+
+ def _print_container(self, container, out, level=0):
+ spaces = ' ' * level
+ out.append(''.join([spaces, 'message {} '.format(container.name)]))
+ out.append(''.join('{\n'))
+ for idx, l in enumerate(container.leafs):
+ leafspaces = ''.join([spaces, ' '])
+ out.append(''.join([leafspaces, '{}{} {} = {} ;\n'.format(
+ 'repeated ' if l.leaf_list else '',
+ l.type,
+ l.name,
+ idx + 1)]))
+
+ for inner in container.containers:
+ self._print_container(inner, out, level + 1)
+
+ out.append(''.join([spaces, '}\n']))
+
+ def _print_list(self, ylist, out):
+ out.append('message {} '.format(ylist.name))
+ out.append('{\n')
+ for idx, l in enumerate(ylist.leafs):
+ leafspaces = ' '
+ out.append(''.join([leafspaces, '{}{} {} = {} ;\n'.format(
+ 'repeated ' if l.leaf_list else '',
+ l.type,
+ l.name,
+ idx + 1)]))
+ out.append('}\n')
+
+ def print_proto(self):
+ out = []
+ for h in self.headers:
+ out.append('{}\n'.format(h))
+ out.append('\n')
+ for m in self.messages:
+ out.append('{}\n'.format(m))
+ out.append('\n')
+ for l in self.ylist:
+ self._print_list(l, out)
+ out.append('\n')
+ for c in self.containers:
+ self._print_container(c, out)
+ out.append('\n')
+
+ return out
+
+
+class YangContainer():
+ def __init__(self):
+ self.name = None
+ self.containers = []
+ self.enums = []
+ self.leafs = []
+
+
+class YangList():
+ def __init__(self):
+ self.name = None
+ self.leafs = []
+
+
+class YangLeaf():
+ def __init__(self):
+ self.name = None
+ self.type = None
+ self.leaf_list = False
+ self.description = None
+
+
+class ProtobufPlugin(plugin.PyangPlugin):
+ def add_output_format(self, fmts):
+ self.multiple_modules = True
+ fmts['protobuf'] = self
+
+ def setup_fmt(self, ctx):
+ ctx.implicit_errors = False
+
+ def emit(self, ctx, modules, fd):
+ """Main control function.
+ """
+ self.real_prefix = unique_prefixes(ctx)
+
+ for m in modules:
+ proto = Protobuf()
+ proto.set_headers(m.i_modulename)
+ self.process_children(m, proto, None)
+ out = proto.print_proto()
+ for i in out:
+ fd.write(i)
+
+ def process_children(self, node, parent, pmod):
+ """Process all children of `node`, except "rpc" and "notification".
+ """
+ for ch in node.i_children:
+ if ch.keyword in ["rpc", "notification"]: continue
+ if ch.keyword in ["choice", "case"]:
+ self.process_children(ch, parent, pmod)
+ continue
+ if ch.i_module.i_modulename == pmod:
+ nmod = pmod
+ nodename = ch.arg
+ print pmod, nodename
+ else:
+ nmod = ch.i_module.i_modulename
+ nodename = "%s:%s" % (nmod, ch.arg)
+ ndata = [ch.keyword]
+ if ch.keyword == "container":
+ print ch.keyword
+ c = YangContainer()
+ c.name = ch.arg
+ self.process_children(ch, c, nmod)
+ parent.containers.append(c)
+ # self.process_container(ch, p, nmod)
+ elif ch.keyword == "list":
+ l = YangList()
+ l.name = ch.arg
+ self.process_children(ch, l, nmod)
+ parent.ylist.append(l)
+ elif ch.keyword in ["leaf", "leaf-list"]:
+ self.process_leaf(ch, parent, ch.keyword == "leaf-list")
+
+ def process_leaf(self, node, parent, leaf_list=False):
+ # Leaf have specific sub statements
+ leaf = YangLeaf()
+ leaf.name = node.arg
+ leaf.type = self.get_protobuf_type(node.search_one("type"))
+ # leaf.type = self.base_type(node.search_one("type"))
+ leaf.description = node.search_one("description")
+ leaf.leaf_list = leaf_list
+ parent.leafs.append(leaf)
+
+ def get_protobuf_type(self, type):
+ protobuf_types_map = dict(
+ binary='Any',
+ bits='bytes',
+ boolean='bool',
+ decimal64='sint64',
+ empty='string',
+ int8='int32',
+ int16='int32',
+ int32='int32',
+ int64='int64',
+ string='string',
+ uint8='uint32',
+ uint16='uint32',
+ uint32='uint32',
+ uint64='uint64',
+ union='OneOf',
+ enumeration='enum'
+ )
+ type = self.base_type(type)
+ if protobuf_types_map[type]:
+ return protobuf_types_map[type]
+ else:
+ return type
+
+ def base_type(self, type):
+ """Return the base type of `type`."""
+ while 1:
+ if type.arg == "leafref":
+ node = type.i_type_spec.i_target_node
+ elif type.i_typedef is None:
+ break
+ else:
+ node = type.i_typedef
+ type = node.search_one("type")
+ if type.arg == "decimal64":
+ return [type.arg, int(type.search_one("fraction-digits").arg)]
+ elif type.arg == "union":
+ return [type.arg,
+ [self.base_type(x) for x in type.i_type_spec.types]]
+ else:
+ return type.arg