xref: /aosp_15_r20/external/cronet/net/third_party/quiche/src/quiche/common/platform/api/quiche_mem_slice.h (revision 6777b5387eb2ff775bb5750e3f5d96f37fb7352b)
1 // Copyright 2017 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef QUICHE_COMMON_PLATFORM_API_QUICHE_MEM_SLICE_H_
6 #define QUICHE_COMMON_PLATFORM_API_QUICHE_MEM_SLICE_H_
7 
8 #include <cstddef>
9 #include <memory>
10 #include <utility>
11 
12 #include "quiche_platform_impl/quiche_mem_slice_impl.h"
13 
14 #include "absl/strings/string_view.h"
15 #include "quiche/common/platform/api/quiche_export.h"
16 #include "quiche/common/quiche_buffer_allocator.h"
17 #include "quiche/common/quiche_callbacks.h"
18 
19 namespace quiche {
20 
21 // QuicheMemSlice is a wrapper around a platform-specific I/O buffer type. It
22 // may be reference counted, though QUICHE itself does not rely on that.
23 class QUICHE_EXPORT QuicheMemSlice {
24  public:
25   // Constructs a empty QuicheMemSlice with no underlying data.
26   QuicheMemSlice() = default;
27 
28   // Constructs a QuicheMemSlice that takes ownership of |buffer|.  The length
29   // of the |buffer| must not be zero.  To construct an empty QuicheMemSlice,
30   // use the zero-argument constructor instead.
QuicheMemSlice(QuicheBuffer buffer)31   explicit QuicheMemSlice(QuicheBuffer buffer) : impl_(std::move(buffer)) {}
32 
33   // Constructs a QuicheMemSlice that takes ownership of |buffer| allocated on
34   // heap.  |length| must not be zero.
QuicheMemSlice(std::unique_ptr<char[]> buffer,size_t length)35   QuicheMemSlice(std::unique_ptr<char[]> buffer, size_t length)
36       : impl_(std::move(buffer), length) {}
37 
QuicheMemSlice(const char * buffer,size_t length,quiche::SingleUseCallback<void (const char *)> done_callback)38   QuicheMemSlice(const char* buffer, size_t length,
39                  quiche::SingleUseCallback<void(const char*)> done_callback)
40       : impl_(buffer, length, std::move(done_callback)) {}
41 
42   // Ensures the use of the in-place constructor (below) is intentional.
43   struct InPlace {};
44 
45   // Constructs a QuicheMemSlice by constructing |impl_| in-place.
46   template <typename... Args>
QuicheMemSlice(InPlace,Args &&...args)47   explicit QuicheMemSlice(InPlace, Args&&... args)
48       : impl_{std::forward<Args>(args)...} {}
49 
50   QuicheMemSlice(const QuicheMemSlice& other) = delete;
51   QuicheMemSlice& operator=(const QuicheMemSlice& other) = delete;
52 
53   // Move constructors. |other| will not hold a reference to the data buffer
54   // after this call completes.
55   QuicheMemSlice(QuicheMemSlice&& other) = default;
56   QuicheMemSlice& operator=(QuicheMemSlice&& other) = default;
57 
58   ~QuicheMemSlice() = default;
59 
60   // Release the underlying reference. Further access the memory will result in
61   // undefined behavior.
Reset()62   void Reset() { impl_.Reset(); }
63 
64   // Returns a const char pointer to underlying data buffer.
data()65   const char* data() const { return impl_.data(); }
66   // Returns the length of underlying data buffer.
length()67   size_t length() const { return impl_.length(); }
68   // Returns the representation of the underlying data as a string view.
AsStringView()69   absl::string_view AsStringView() const {
70     return absl::string_view(data(), length());
71   }
72 
empty()73   bool empty() const { return impl_.empty(); }
74 
75  private:
76   QuicheMemSliceImpl impl_;
77 };
78 
79 }  // namespace quiche
80 
81 #endif  // QUICHE_COMMON_PLATFORM_API_QUICHE_MEM_SLICE_H_
82