1 #ifndef GOOGLE_PROTOBUF_RUST_CPP_KERNEL_MAP_H__
2 #define GOOGLE_PROTOBUF_RUST_CPP_KERNEL_MAP_H__
3
4 #include <memory>
5 #include <type_traits>
6
7 #include "google/protobuf/map.h"
8 #include "google/protobuf/message_lite.h"
9 #include "rust/cpp_kernel/strings.h"
10
11 namespace google {
12 namespace protobuf {
13 namespace rust {
14
15 // String and bytes values are passed across the FFI boundary as owned raw
16 // pointers when we do map insertions. Unlike other types, they have to be
17 // explicitly deleted. This MakeCleanup() helper does nothing by default, but
18 // for std::string pointers it returns a std::unique_ptr to take ownership of
19 // the raw pointer.
20 template <typename T>
MakeCleanup(T value)21 auto MakeCleanup(T value) {
22 if constexpr (std::is_same<T, std::string*>::value) {
23 return std::unique_ptr<std::string>(value);
24 } else {
25 return 0;
26 }
27 }
28
29 } // namespace rust
30 } // namespace protobuf
31 } // namespace google
32
33 // Defines concrete thunks to access typed map methods from Rust.
34 #define __PB_RUST_EXPOSE_SCALAR_MAP_METHODS( \
35 key_ty, rust_key_ty, ffi_key_ty, to_cpp_key, to_ffi_key, value_ty, \
36 rust_value_ty, ffi_view_ty, ffi_value_ty, to_cpp_value, to_ffi_value) \
37 google::protobuf::Map<key_ty, value_ty>* \
38 proto2_rust_thunk_Map_##rust_key_ty##_##rust_value_ty##_new() { \
39 return new google::protobuf::Map<key_ty, value_ty>(); \
40 } \
41 void proto2_rust_thunk_Map_##rust_key_ty##_##rust_value_ty##_free( \
42 google::protobuf::Map<key_ty, value_ty>* m) { \
43 delete m; \
44 } \
45 void proto2_rust_thunk_Map_##rust_key_ty##_##rust_value_ty##_clear( \
46 google::protobuf::Map<key_ty, value_ty>* m) { \
47 m->clear(); \
48 } \
49 size_t proto2_rust_thunk_Map_##rust_key_ty##_##rust_value_ty##_size( \
50 const google::protobuf::Map<key_ty, value_ty>* m) { \
51 return m->size(); \
52 } \
53 bool proto2_rust_thunk_Map_##rust_key_ty##_##rust_value_ty##_insert( \
54 google::protobuf::Map<key_ty, value_ty>* m, ffi_key_ty key, ffi_value_ty value) { \
55 auto cleanup = google::protobuf::rust::MakeCleanup(value); \
56 (void)cleanup; \
57 auto iter_and_inserted = m->try_emplace(to_cpp_key, to_cpp_value); \
58 if (!iter_and_inserted.second) { \
59 iter_and_inserted.first->second = to_cpp_value; \
60 } \
61 return iter_and_inserted.second; \
62 } \
63 bool proto2_rust_thunk_Map_##rust_key_ty##_##rust_value_ty##_get( \
64 const google::protobuf::Map<key_ty, value_ty>* m, ffi_key_ty key, \
65 ffi_view_ty* value) { \
66 auto cpp_key = to_cpp_key; \
67 auto it = m->find(cpp_key); \
68 if (it == m->end()) { \
69 return false; \
70 } \
71 auto& cpp_value = it->second; \
72 *value = to_ffi_value; \
73 return true; \
74 } \
75 google::protobuf::internal::UntypedMapIterator \
76 proto2_rust_thunk_Map_##rust_key_ty##_##rust_value_ty##_iter( \
77 const google::protobuf::Map<key_ty, value_ty>* m) { \
78 return google::protobuf::internal::UntypedMapIterator::FromTyped(m->cbegin()); \
79 } \
80 void proto2_rust_thunk_Map_##rust_key_ty##_##rust_value_ty##_iter_get( \
81 const google::protobuf::internal::UntypedMapIterator* iter, ffi_key_ty* key, \
82 ffi_view_ty* value) { \
83 auto typed_iter = \
84 iter->ToTyped<google::protobuf::Map<key_ty, value_ty>::const_iterator>(); \
85 const auto& cpp_key = typed_iter->first; \
86 const auto& cpp_value = typed_iter->second; \
87 *key = to_ffi_key; \
88 *value = to_ffi_value; \
89 } \
90 bool proto2_rust_thunk_Map_##rust_key_ty##_##rust_value_ty##_remove( \
91 google::protobuf::Map<key_ty, value_ty>* m, ffi_key_ty key, ffi_view_ty* value) { \
92 auto cpp_key = to_cpp_key; \
93 auto num_removed = m->erase(cpp_key); \
94 return num_removed > 0; \
95 }
96
97 // Defines the map thunks for all supported key types for a given value type.
98 #define __PB_RUST_EXPOSE_SCALAR_MAP_METHODS_FOR_VALUE_TYPE( \
99 value_ty, rust_value_ty, ffi_view_ty, ffi_value_ty, to_cpp_value, \
100 to_ffi_value) \
101 __PB_RUST_EXPOSE_SCALAR_MAP_METHODS( \
102 int32_t, i32, int32_t, key, cpp_key, value_ty, rust_value_ty, \
103 ffi_view_ty, ffi_value_ty, to_cpp_value, to_ffi_value); \
104 __PB_RUST_EXPOSE_SCALAR_MAP_METHODS( \
105 uint32_t, u32, uint32_t, key, cpp_key, value_ty, rust_value_ty, \
106 ffi_view_ty, ffi_value_ty, to_cpp_value, to_ffi_value); \
107 __PB_RUST_EXPOSE_SCALAR_MAP_METHODS( \
108 bool, bool, bool, key, cpp_key, value_ty, rust_value_ty, ffi_view_ty, \
109 ffi_value_ty, to_cpp_value, to_ffi_value); \
110 __PB_RUST_EXPOSE_SCALAR_MAP_METHODS( \
111 uint64_t, u64, uint64_t, key, cpp_key, value_ty, rust_value_ty, \
112 ffi_view_ty, ffi_value_ty, to_cpp_value, to_ffi_value); \
113 __PB_RUST_EXPOSE_SCALAR_MAP_METHODS( \
114 int64_t, i64, int64_t, key, cpp_key, value_ty, rust_value_ty, \
115 ffi_view_ty, ffi_value_ty, to_cpp_value, to_ffi_value); \
116 __PB_RUST_EXPOSE_SCALAR_MAP_METHODS( \
117 std::string, ProtoString, google::protobuf::rust::PtrAndLen, \
118 std::string(key.ptr, key.len), \
119 (google::protobuf::rust::PtrAndLen{cpp_key.data(), cpp_key.size()}), value_ty, \
120 rust_value_ty, ffi_view_ty, ffi_value_ty, to_cpp_value, to_ffi_value);
121
122 #endif // GOOGLE_PROTOBUF_RUST_CPP_KERNEL_MAP_H__
123