include/flatbuffers/buffer_ref.h

0001 /*
0002  * Copyright 2021 Google Inc. All rights reserved.
0003  *
0004  * Licensed under the Apache License, Version 2.0 (the "License");
0005  * you may not use this file except in compliance with the License.
0006  * You may obtain a copy of the License at
0007  *
0008  *     http://www.apache.org/licenses/LICENSE-2.0
0009  *
0010  * Unless required by applicable law or agreed to in writing, software
0011  * distributed under the License is distributed on an "AS IS" BASIS,
0012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
0013  * See the License for the specific language governing permissions and
0014  * limitations under the License.
0015  */
0016
0017 #ifndef FLATBUFFERS_BUFFER_REF_H_
0018 #define FLATBUFFERS_BUFFER_REF_H_
0019
0020 #include "flatbuffers/base.h"
0021 #include "flatbuffers/verifier.h"
0022
0023 namespace flatbuffers {
0024
0025 // Convenient way to bundle a buffer and its length, to pass it around
0026 // typed by its root.
0027 // A BufferRef does not own its buffer.
0028 struct BufferRefBase {};  // for std::is_base_of
0029
0030 template<typename T> struct BufferRef : BufferRefBase {
0031   BufferRef() : buf(nullptr), len(0), must_free(false) {}
0032   BufferRef(uint8_t *_buf, uoffset_t _len)
0033       : buf(_buf), len(_len), must_free(false) {}
0034
0035   ~BufferRef() {
0036     if (must_free) free(buf);
0037   }
0038
0039   const T *GetRoot() const { return flatbuffers::GetRoot<T>(buf); }
0040
0041   bool Verify() {
0042     Verifier verifier(buf, len);
0043     return verifier.VerifyBuffer<T>(nullptr);
0044   }
0045
0046   uint8_t *buf;
0047   uoffset_t len;
0048   bool must_free;
0049 };
0050
0051 }  // namespace flatbuffers
0052
0053 #endif  // FLATBUFFERS_BUFFER_REF_H_