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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 // Finds the tag numbers used by all known extensions of
147 // containing_type, and appends them to output in an undefined
148 // order.
149 // Python DescriptorDatabases are not required to implement this method.
FindAllExtensionNumbers(const string & containing_type,std::vector<int> * output)150 bool PyDescriptorDatabase::FindAllExtensionNumbers(
151     const string& containing_type, std::vector<int>* output) {
152   ScopedPyObjectPtr py_method(
153       PyObject_GetAttrString(py_database_, "FindAllExtensionNumbers"));
154   if (py_method == NULL) {
155     // This method is not implemented, returns without error.
156     PyErr_Clear();
157     return false;
158   }
159   ScopedPyObjectPtr py_list(
160       PyObject_CallFunction(py_method.get(), "s#", containing_type.c_str(),
161                             containing_type.size()));
162   if (py_list == NULL) {
163     PyErr_Print();
164     return false;
165   }
166   Py_ssize_t size = PyList_Size(py_list.get());
167   int64 item_value;
168   for (Py_ssize_t i = 0 ; i < size; ++i) {
169     ScopedPyObjectPtr item(PySequence_GetItem(py_list.get(), i));
170     item_value = PyLong_AsLong(item.get());
171     if (item_value < 0) {
172       GOOGLE_LOG(ERROR)
173           << "FindAllExtensionNumbers method did not return "
174           << "valid extension numbers.";
175       PyErr_Print();
176       return false;
177     }
178     output->push_back(item_value);
179   }
180   return true;
181 }
182 
183 }  // namespace python
184 }  // namespace protobuf
185 }  // namespace google
186