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30 
31 // Author: anuraag@google.com (Anuraag Agrawal)
32 // Author: tibell@google.com (Johan Tibell)
33 
34 #ifndef GOOGLE_PROTOBUF_PYTHON_CPP_REPEATED_COMPOSITE_CONTAINER_H__
35 #define GOOGLE_PROTOBUF_PYTHON_CPP_REPEATED_COMPOSITE_CONTAINER_H__
36 
37 #include <Python.h>
38 
39 #include <memory>
40 #ifndef _SHARED_PTR_H
41 #include <google/protobuf/stubs/shared_ptr.h>
42 #endif
43 #include <string>
44 #include <vector>
45 
46 
47 namespace google {
48 namespace protobuf {
49 
50 class FieldDescriptor;
51 class Message;
52 
53 using internal::shared_ptr;
54 
55 namespace python {
56 
57 struct CMessage;
58 struct CFieldDescriptor;
59 
60 // A RepeatedCompositeContainer can be in one of two states: attached
61 // or released.
62 //
63 // When in the attached state all modifications to the container are
64 // done both on the 'message' and on the 'child_messages'
65 // list.  In this state all Messages refered to by the children in
66 // 'child_messages' are owner by the 'owner'.
67 //
68 // When in the released state 'message', 'owner', 'parent', and
69 // 'parent_field' are NULL.
70 typedef struct RepeatedCompositeContainer {
71   PyObject_HEAD;
72 
73   // This is the top-level C++ Message object that owns the whole
74   // proto tree.  Every Python RepeatedCompositeContainer holds a
75   // reference to it in order to keep it alive as long as there's a
76   // Python object that references any part of the tree.
77   shared_ptr<Message> owner;
78 
79   // Weak reference to parent object. May be NULL. Used to make sure
80   // the parent is writable before modifying the
81   // RepeatedCompositeContainer.
82   CMessage* parent;
83 
84   // A descriptor used to modify the underlying 'message'.
85   CFieldDescriptor* parent_field;
86 
87   // Pointer to the C++ Message that contains this container.  The
88   // RepeatedCompositeContainer does not own this pointer.
89   //
90   // If NULL, this message has been released from its parent (by
91   // calling Clear() or ClearField() on the parent.
92   Message* message;
93 
94   // A callable that is used to create new child messages.
95   PyObject* subclass_init;
96 
97   // A list of child messages.
98   PyObject* child_messages;
99 } RepeatedCompositeContainer;
100 
101 extern PyTypeObject RepeatedCompositeContainer_Type;
102 
103 namespace repeated_composite_container {
104 
105 // Returns the number of items in this repeated composite container.
106 static Py_ssize_t Length(RepeatedCompositeContainer* self);
107 
108 // Appends a new CMessage to the container and returns it.  The
109 // CMessage is initialized using the content of kwargs.
110 //
111 // Returns a new reference if successful; returns NULL and sets an
112 // exception if unsuccessful.
113 PyObject* Add(RepeatedCompositeContainer* self,
114               PyObject* args,
115               PyObject* kwargs);
116 
117 // Appends all the CMessages in the input iterator to the container.
118 //
119 // Returns None if successful; returns NULL and sets an exception if
120 // unsuccessful.
121 PyObject* Extend(RepeatedCompositeContainer* self, PyObject* value);
122 
123 // Appends a new message to the container for each message in the
124 // input iterator, merging each data element in. Equivalent to extend.
125 //
126 // Returns None if successful; returns NULL and sets an exception if
127 // unsuccessful.
128 PyObject* MergeFrom(RepeatedCompositeContainer* self, PyObject* other);
129 
130 // Accesses messages in the container.
131 //
132 // Returns a new reference to the message for an integer parameter.
133 // Returns a new reference to a list of messages for a slice.
134 PyObject* Subscript(RepeatedCompositeContainer* self, PyObject* slice);
135 
136 // Deletes items from the container (cannot be used for assignment).
137 //
138 // Returns 0 on success, -1 on failure.
139 int AssignSubscript(RepeatedCompositeContainer* self,
140                     PyObject* slice,
141                     PyObject* value);
142 
143 // Releases the messages in the container to the given message.
144 //
145 // Returns 0 on success, -1 on failure.
146 int ReleaseToMessage(RepeatedCompositeContainer* self,
147                      google::protobuf::Message* new_message);
148 
149 // Releases the messages in the container to a new message.
150 //
151 // Returns 0 on success, -1 on failure.
152 int Release(RepeatedCompositeContainer* self);
153 
154 // Returns 0 on success, -1 on failure.
155 int SetOwner(RepeatedCompositeContainer* self,
156              const shared_ptr<Message>& new_owner);
157 
158 // Removes the last element of the repeated message field 'field' on
159 // the Message 'message', and transfers the ownership of the released
160 // Message to 'cmessage'.
161 //
162 // Corresponds to reflection api method ReleaseMessage.
163 void ReleaseLastTo(const FieldDescriptor* field,
164                    Message* message,
165                    CMessage* cmessage);
166 
167 }  // namespace repeated_composite_container
168 }  // namespace python
169 }  // namespace protobuf
170 
171 }  // namespace google
172 #endif  // GOOGLE_PROTOBUF_PYTHON_CPP_REPEATED_COMPOSITE_CONTAINER_H__
173