1/*
2 *
3 * Copyright 2015 gRPC authors.
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 */
18
19#ifndef GRPCPP_IMPL_CODEGEN_SLICE_H
20#define GRPCPP_IMPL_CODEGEN_SLICE_H
21
22#include <grpcpp/impl/codegen/config.h>
23#include <grpcpp/impl/codegen/core_codegen_interface.h>
24#include <grpcpp/impl/codegen/string_ref.h>
25
26#include <grpc/impl/codegen/slice.h>
27
28namespace grpc {
29
30/// A wrapper around \a grpc_slice.
31///
32/// A slice represents a contiguous reference counted array of bytes.
33/// It is cheap to take references to a slice, and it is cheap to create a
34/// slice pointing to a subset of another slice.
35class Slice final {
36 public:
37 /// Construct an empty slice.
38 Slice() : slice_(g_core_codegen_interface->grpc_empty_slice()) {}
39 /// Destructor - drops one reference.
40 ~Slice() { g_core_codegen_interface->grpc_slice_unref(slice: slice_); }
41
42 enum AddRef { ADD_REF };
43 /// Construct a slice from \a slice, adding a reference.
44 Slice(grpc_slice slice, AddRef)
45 : slice_(g_core_codegen_interface->grpc_slice_ref(slice)) {}
46
47 enum StealRef { STEAL_REF };
48 /// Construct a slice from \a slice, stealing a reference.
49 Slice(grpc_slice slice, StealRef) : slice_(slice) {}
50
51 /// Allocate a slice of specified size
52 Slice(size_t len)
53 : slice_(g_core_codegen_interface->grpc_slice_malloc(length: len)) {}
54
55 /// Construct a slice from a copied buffer
56 Slice(const void* buf, size_t len)
57 : slice_(g_core_codegen_interface->grpc_slice_from_copied_buffer(
58 buffer: reinterpret_cast<const char*>(buf), length: len)) {}
59
60 /// Construct a slice from a copied string
61 Slice(const grpc::string& str)
62 : slice_(g_core_codegen_interface->grpc_slice_from_copied_buffer(
63 buffer: str.c_str(), length: str.length())) {}
64
65 enum StaticSlice { STATIC_SLICE };
66
67 /// Construct a slice from a static buffer
68 Slice(const void* buf, size_t len, StaticSlice)
69 : slice_(g_core_codegen_interface->grpc_slice_from_static_buffer(
70 buffer: reinterpret_cast<const char*>(buf), length: len)) {}
71
72 /// Copy constructor, adds a reference.
73 Slice(const Slice& other)
74 : slice_(g_core_codegen_interface->grpc_slice_ref(slice: other.slice_)) {}
75
76 /// Assignment, reference count is unchanged.
77 Slice& operator=(Slice other) {
78 std::swap(a&: slice_, b&: other.slice_);
79 return *this;
80 }
81
82 /// Create a slice pointing at some data. Calls malloc to allocate a refcount
83 /// for the object, and arranges that destroy will be called with the
84 /// user data pointer passed in at destruction. Can be the same as buf or
85 /// different (e.g., if data is part of a larger structure that must be
86 /// destroyed when the data is no longer needed)
87 Slice(void* buf, size_t len, void (*destroy)(void*), void* user_data)
88 : slice_(g_core_codegen_interface->grpc_slice_new_with_user_data(
89 p: buf, len, destroy, user_data)) {}
90
91 /// Specialization of above for common case where buf == user_data
92 Slice(void* buf, size_t len, void (*destroy)(void*))
93 : Slice(buf, len, destroy, buf) {}
94
95 /// Similar to the above but has a destroy that also takes slice length
96 Slice(void* buf, size_t len, void (*destroy)(void*, size_t))
97 : slice_(g_core_codegen_interface->grpc_slice_new_with_len(p: buf, len,
98 destroy)) {}
99
100 /// Byte size.
101 size_t size() const { return GRPC_SLICE_LENGTH(slice_); }
102
103 /// Raw pointer to the beginning (first element) of the slice.
104 const uint8_t* begin() const { return GRPC_SLICE_START_PTR(slice_); }
105
106 /// Raw pointer to the end (one byte \em past the last element) of the slice.
107 const uint8_t* end() const { return GRPC_SLICE_END_PTR(slice_); }
108
109 /// Raw C slice. Caller needs to call grpc_slice_unref when done.
110 grpc_slice c_slice() const {
111 return g_core_codegen_interface->grpc_slice_ref(slice: slice_);
112 }
113
114 private:
115 friend class ByteBuffer;
116
117 grpc_slice slice_;
118};
119
120inline grpc::string_ref StringRefFromSlice(const grpc_slice* slice) {
121 return grpc::string_ref(
122 reinterpret_cast<const char*>(GRPC_SLICE_START_PTR(*slice)),
123 GRPC_SLICE_LENGTH(*slice));
124}
125
126inline grpc::string StringFromCopiedSlice(grpc_slice slice) {
127 return grpc::string(reinterpret_cast<char*>(GRPC_SLICE_START_PTR(slice)),
128 GRPC_SLICE_LENGTH(slice));
129}
130
131inline grpc_slice SliceReferencingString(const grpc::string& str) {
132 return g_core_codegen_interface->grpc_slice_from_static_buffer(buffer: str.data(),
133 length: str.length());
134}
135
136inline grpc_slice SliceFromCopiedString(const grpc::string& str) {
137 return g_core_codegen_interface->grpc_slice_from_copied_buffer(buffer: str.data(),
138 length: str.length());
139}
140
141} // namespace grpc
142
143#endif // GRPCPP_IMPL_CODEGEN_SLICE_H
144

source code of include/grpcpp/impl/codegen/slice.h