pyang plugin to generate of_config.generated_classes

the current version of generated_classes was written by hand.
this plugin allows it to be auto-generated from the yang module
of OF-Config if/when it's available.

unfortunately, there seems to be no yang modules usable for this
purpose publically available yet, though.
the yang module of OF-Config 1.1.1 is embedded in pdf.  besides that
it's hard to extract from the pdf, its license is unclear.
OF-Config 1.2 says that its yang module is distributed as a separate
file.  but i couldn't find it on ONF site.

Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

tools/pyang_plugins/__init__.py

@@ -0,0 +1,15 @@
+# Copyright (C) 2013,2014 Nippon Telegraph and Telephone Corporation.
+# Copyright (C) 2013,2014 YAMAMOTO Takashi <yamamoto at valinux co jp>
+#
+# 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.

tools/pyang_plugins/ryu.py

@@ -0,0 +1,180 @@
+# Copyright (C) 2013,2014 Nippon Telegraph and Telephone Corporation.
+# Copyright (C) 2013,2014 YAMAMOTO Takashi <yamamoto at valinux co jp>
+#
+# 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.
+
+# this is a pyang plugin to generate ryu/lib/of_config/generated_classes.py
+# usage example:
+# PYTHONPATH=. ./bin/pyang --plugindir ~/git/ryu/tools/pyang_plugins -f ryu ~/git/ryu/tools/of-config1.1.1.yang > ~/git/ryu/lib/of_config/generated_classes.py
+
+
+_COPYRIGHT_NOTICE = """
+# Copyright (C) 2013,2014 Nippon Telegraph and Telephone Corporation.
+# Copyright (C) 2013,2014 YAMAMOTO Takashi <yamamoto at valinux co jp>
+#
+# 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.
+"""
+
+
+import sys
+import StringIO
+import pyang
+from pyang import plugin
+
+
+def pyang_plugin_init():
+    plugin.register_plugin(RyuPlugin())
+
+
+class RyuPlugin(plugin.PyangPlugin):
+    def add_output_format(self, fmts):
+        fmts['ryu'] = self
+
+    def emit(self, ctx, modules, fd):
+        emit_ryu(ctx, modules[0], fd)
+
+
+def emit_ryu(ctx, module, fd):
+    ctx.i_ryu_queue = []
+    visit_children(ctx, module, fd, module.i_children)
+    ctx.i_ryu_queue.reverse()
+    generate_header(ctx)
+    done = set()
+    for s in ctx.i_ryu_queue:
+        name = generate_type_name(s)
+        if name in done:
+            continue
+        generate_class(s)
+        done.add(name)
+
+
+def visit_children(ctx, module, fd, children, prefix=''):
+    for c in children:
+        if not is_leaf(c):
+            ctx.i_ryu_queue.append(c)
+        if hasattr(c, 'i_children'):
+            visit_children(ctx, module, fd, c.i_children, prefix + '  ')
+
+
+def is_leaf(s):
+    return s.keyword in ['leaf', 'leaf-list']
+
+
+def generate_header(ctx):
+    print _COPYRIGHT_NOTICE
+    print '# do not edit.'
+    print '# this file was mechanically generated with:'
+    print '#    pyang %s' % pyang.__version__
+    print '#    ryu.tools.pyang_plugins.ryu'
+    for mod, ver in sorted(ctx.modules):
+        print '#    %s@%s' % (mod, ver)
+    print ''
+    print 'from ryu.lib.of_config.base import _Base, _e, _ct'
+
+
+def generate_class_def(s):
+    try:
+        return s.i_ryu_class_def
+    except AttributeError:
+        pass
+    s.i_ryu_class_def = _generate_class_def(s)
+    return s.i_ryu_class_def
+
+
+def _generate_class_def(s):
+    if is_leaf(s):
+        return generate_type_name(s)
+    o = StringIO.StringIO()
+    print >> o, 'class %s(_Base):' % (generate_type_name(s),)
+    print >> o, '    _ELEMENTS = ['
+    for c in s.i_children:
+        if is_leaf(c):
+            print >> o, '        _e(\'%s\', is_list=%s),  # %s' % \
+                (c.arg, c.keyword == 'leaf-list', generate_type_name(c),)
+        else:
+            print >> o, '        _ct(\'%s\',' % (c.arg,)
+            print >> o, '            %s,' % (generate_type_name(c),)
+            print >> o, '            is_list=%s),' % (c.keyword == 'list',)
+    print >> o, '    ]'
+    return o.getvalue()
+
+
+def generate_class(s):
+    print ''
+    print ''
+    sys.stdout.write(generate_class_def(s))
+
+
+def same_class_def(s1, s2):
+    return generate_class_def(s1) == generate_class_def(s2)
+
+
+# 'hoge-hoge' -> 'HogeHoge'
+def pythonify(name):
+    a = name.split('-')
+    a = map(lambda x: x.capitalize(), a)  # XXX locale sensitive
+    return ''.join(a)
+
+
+def chop_suf(s, suf):
+    if not s.endswith(suf):
+        return s
+    return s[:-len(suf)]
+
+
+_classes = {}
+
+
+def generate_type_name(s):
+    try:
+        return s.i_ryu_class_name
+    except AttributeError:
+        pass
+    s.i_ryu_class_name = name = _generate_type_name(s)
+    assert (not name in _classes) or same_class_def(_classes[name], s)
+    _classes[name] = s
+    return name
+
+
+def _generate_type_name(s):
+    # 1. use the hardcoded name for the top level capable-switch.
+    if s.arg == 'capable-switch':
+        return 'OFCapableSwitchType'
+    # 2. pick the name from the first yang grouping.
+    # this relies on the way OF-Config yang specification is written.
+    t = s.search_one('uses')
+    if t:
+        return t.arg
+    # 3. pick the name of yang type.
+    t = s.search_one('type')
+    if t:
+        return t.arg
+    # 4. infer from the parent's name.
+    # if the parent is 'OFFooType' and our name is 'bar-baz',
+    # use 'OFFooBarBazType'.
+    # again, this relies on the way OF-Config yang specification is written.
+    return (chop_suf(generate_type_name(s.parent), 'Type')
+            + pythonify(s.arg)
+            + 'Type')