1 // Copyright 2023 The Pigweed Authors
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not
4 // use this file except in compliance with the License. You may obtain a copy of
5 // the License at
6 //
7 //     https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
12 // License for the specific language governing permissions and limitations under
13 // the License.
14 
15 #pragma once
16 #include "pw_bluetooth_sapphire/internal/host/common/assert.h"
17 #include "pw_bluetooth_sapphire/internal/host/common/byte_buffer.h"
18 
19 namespace bt {
20 
21 template <size_t BackingBufferSize>
22 class SlabBuffer : public MutableByteBuffer {
23  public:
SlabBuffer(size_t size)24   explicit SlabBuffer(size_t size) : size_(size) {
25     PW_CHECK(size);
26     PW_CHECK(size_ <= buffer_.size());
27   }
28 
29   // ByteBuffer overrides:
data()30   const uint8_t* data() const override { return buffer_.data(); }
size()31   size_t size() const override { return size_; }
cbegin()32   const_iterator cbegin() const override { return buffer_.cbegin(); }
cend()33   const_iterator cend() const override { return cbegin() + size_; }
34 
35   // MutableByteBuffer overrides:
mutable_data()36   uint8_t* mutable_data() override { return buffer_.mutable_data(); }
Fill(uint8_t value)37   void Fill(uint8_t value) override {
38     buffer_.mutable_view(0, size_).Fill(value);
39   }
40 
41  private:
42   size_t size_;
43 
44   // The backing backing buffer can have a different size from what was
45   // requested.
46   StaticByteBuffer<BackingBufferSize> buffer_;
47 
48   BT_DISALLOW_COPY_AND_ASSIGN_ALLOW_MOVE(SlabBuffer);
49 };
50 
51 }  // namespace bt
52