1 // Protocol Buffers - Google's data interchange format
2 // Copyright 2008 Google Inc. All rights reserved.
3 // https://developers.google.com/protocol-buffers/
4 //
5 // Redistribution and use in source and binary forms, with or without
6 // modification, are permitted provided that the following conditions are
7 // met:
8 //
9 // * Redistributions of source code must retain the above copyright
10 // notice, this list of conditions and the following disclaimer.
11 // * Redistributions in binary form must reproduce the above
12 // copyright notice, this list of conditions and the following disclaimer
13 // in the documentation and/or other materials provided with the
14 // distribution.
15 // * Neither the name of Google Inc. nor the names of its
16 // contributors may be used to endorse or promote products derived from
17 // this software without specific prior written permission.
18 //
19 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30
31 // This file defines a C++ DescriptorDatabase, which wraps a Python Database
32 // and delegate all its operations to Python methods.
33
34 #include <google/protobuf/pyext/descriptor_database.h>
35
36 #include <google/protobuf/stubs/logging.h>
37 #include <google/protobuf/stubs/common.h>
38 #include <google/protobuf/descriptor.pb.h>
39 #include <google/protobuf/pyext/message.h>
40 #include <google/protobuf/pyext/scoped_pyobject_ptr.h>
41
42 namespace google {
43 namespace protobuf {
44 namespace python {
45
PyDescriptorDatabase(PyObject * py_database)46 PyDescriptorDatabase::PyDescriptorDatabase(PyObject* py_database)
47 : py_database_(py_database) {
48 Py_INCREF(py_database_);
49 }
50
~PyDescriptorDatabase()51 PyDescriptorDatabase::~PyDescriptorDatabase() { Py_DECREF(py_database_); }
52
53 // Convert a Python object to a FileDescriptorProto pointer.
54 // Handles all kinds of Python errors, which are simply logged.
GetFileDescriptorProto(PyObject * py_descriptor,FileDescriptorProto * output)55 static bool GetFileDescriptorProto(PyObject* py_descriptor,
56 FileDescriptorProto* output) {
57 if (py_descriptor == NULL) {
58 if (PyErr_ExceptionMatches(PyExc_KeyError)) {
59 // Expected error: item was simply not found.
60 PyErr_Clear();
61 } else {
62 GOOGLE_LOG(ERROR) << "DescriptorDatabase method raised an error";
63 PyErr_Print();
64 }
65 return false;
66 }
67 if (py_descriptor == Py_None) {
68 return false;
69 }
70 const Descriptor* filedescriptor_descriptor =
71 FileDescriptorProto::default_instance().GetDescriptor();
72 CMessage* message = reinterpret_cast<CMessage*>(py_descriptor);
73 if (PyObject_TypeCheck(py_descriptor, &CMessage_Type) &&
74 message->message->GetDescriptor() == filedescriptor_descriptor) {
75 // Fast path: Just use the pointer.
76 FileDescriptorProto* file_proto =
77 static_cast<FileDescriptorProto*>(message->message);
78 *output = *file_proto;
79 return true;
80 } else {
81 // Slow path: serialize the message. This allows to use databases which
82 // use a different implementation of FileDescriptorProto.
83 ScopedPyObjectPtr serialized_pb(
84 PyObject_CallMethod(py_descriptor, "SerializeToString", NULL));
85 if (serialized_pb == NULL) {
86 GOOGLE_LOG(ERROR)
87 << "DescriptorDatabase method did not return a FileDescriptorProto";
88 PyErr_Print();
89 return false;
90 }
91 char* str;
92 Py_ssize_t len;
93 if (PyBytes_AsStringAndSize(serialized_pb.get(), &str, &len) < 0) {
94 GOOGLE_LOG(ERROR)
95 << "DescriptorDatabase method did not return a FileDescriptorProto";
96 PyErr_Print();
97 return false;
98 }
99 FileDescriptorProto file_proto;
100 if (!file_proto.ParseFromArray(str, len)) {
101 GOOGLE_LOG(ERROR)
102 << "DescriptorDatabase method did not return a FileDescriptorProto";
103 return false;
104 }
105 *output = file_proto;
106 return true;
107 }
108 }
109
110 // Find a file by file name.
FindFileByName(const string & filename,FileDescriptorProto * output)111 bool PyDescriptorDatabase::FindFileByName(const string& filename,
112 FileDescriptorProto* output) {
113 ScopedPyObjectPtr py_descriptor(PyObject_CallMethod(
114 py_database_, "FindFileByName", "s#", filename.c_str(), filename.size()));
115 return GetFileDescriptorProto(py_descriptor.get(), output);
116 }
117
118 // Find the file that declares the given fully-qualified symbol name.
FindFileContainingSymbol(const string & symbol_name,FileDescriptorProto * output)119 bool PyDescriptorDatabase::FindFileContainingSymbol(
120 const string& symbol_name, FileDescriptorProto* output) {
121 ScopedPyObjectPtr py_descriptor(
122 PyObject_CallMethod(py_database_, "FindFileContainingSymbol", "s#",
123 symbol_name.c_str(), symbol_name.size()));
124 return GetFileDescriptorProto(py_descriptor.get(), output);
125 }
126
127 // Find the file which defines an extension extending the given message type
128 // with the given field number.
129 // Python DescriptorDatabases are not required to implement this method.
FindFileContainingExtension(const string & containing_type,int field_number,FileDescriptorProto * output)130 bool PyDescriptorDatabase::FindFileContainingExtension(
131 const string& containing_type, int field_number,
132 FileDescriptorProto* output) {
133 ScopedPyObjectPtr py_method(
134 PyObject_GetAttrString(py_database_, "FindFileContainingExtension"));
135 if (py_method == NULL) {
136 // This method is not implemented, returns without error.
137 PyErr_Clear();
138 return false;
139 }
140 ScopedPyObjectPtr py_descriptor(
141 PyObject_CallFunction(py_method.get(), "s#i", containing_type.c_str(),
142 containing_type.size(), field_number));
143 return GetFileDescriptorProto(py_descriptor.get(), output);
144 }
145
146 } // namespace python
147 } // namespace protobuf
148 } // namespace google
149