userver: userver/storages/postgres/io/string_types.hpp Source File
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string_types.hpp
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1#pragma once
2
3/// @file userver/storages/postgres/io/string_types.hpp
4/// @brief Strings I/O support
5/// @ingroup userver_postgres_parse_and_format
6
7#include <cstring>
8#include <string>
9#include <string_view>
10
11#include <userver/storages/postgres/exceptions.hpp>
12#include <userver/storages/postgres/io/buffer_io_base.hpp>
13#include <userver/storages/postgres/io/traits.hpp>
14#include <userver/storages/postgres/io/type_mapping.hpp>
15
16USERVER_NAMESPACE_BEGIN
17
18namespace storages::postgres::io {
19
20//@{
21/** @name const char* formatting */
22template <>
23struct BufferFormatter<const char*> {
24 const char* value;
25
26 explicit BufferFormatter(const char* val) : value{val} {}
27
28 template <typename Buffer>
29 void operator()(const UserTypes&, Buffer& buf) const {
30 auto sz = std::strlen(value);
31 WriteN(buf, value, sz);
32 }
33
34 template <typename Buffer>
35 static void WriteN(Buffer& buf, const char* c, std::size_t n) {
36 // Don't copy zero-terminator in binary mode
37 while (n > 0 && c[n - 1] == '\0') {
38 --n;
39 }
40 buf.reserve(buf.size() + n);
41 std::copy(c, c + n, std::back_inserter(buf));
42 }
43};
44//@}
45
46//@{
47/** @name char[N] formatting */
48template <std::size_t N>
49struct BufferFormatter<char[N]> {
50 using CharFormatter = BufferFormatter<const char*>;
51 const char* value;
52
53 explicit BufferFormatter(const char* val) : value{val} {}
54
55 template <typename Buffer>
56 void operator()(const UserTypes&, Buffer& buf) const {
58 }
59};
60
61//@}
62
63//@{
64/** @name std::string I/O */
65template <>
67 using CharFormatter = BufferFormatter<const char*>;
68 const std::string& value;
69
70 explicit BufferFormatter(const std::string& val) : value{val} {}
71 template <typename Buffer>
72 void operator()(const UserTypes&, Buffer& buf) const {
74 }
75};
76
77template <>
80
81 explicit BufferParser(std::string& val) : value{val} {}
82
83 void operator()(const FieldBuffer& buffer);
84};
85//@}
86
87//@{
88/** @name string_view I/O */
89template <>
93 using CharFormatter = BufferFormatter<const char*>;
94
95 using BaseType::BaseType;
96
97 template <typename Buffer>
98 void operator()(const UserTypes&, Buffer& buffer) const {
100 }
101};
102
103template <>
107 using BaseType::BaseType;
108
109 void operator()(const FieldBuffer& buffer) {
110 using std::swap;
111 ValueType tmp{reinterpret_cast<const char*>(buffer.buffer), buffer.length};
112 swap(tmp, value);
113 }
114};
115//@}
116
117//@{
118/** @name char I/O */
119template <>
120struct BufferFormatter<char> {
121 char value;
122
123 explicit BufferFormatter(char val) : value{val} {}
124 template <typename Buffer>
125 void operator()(const UserTypes&, Buffer& buf) const {
127 }
128};
129
130template <>
131struct BufferParser<char> {
132 char& value;
133
134 explicit BufferParser(char& val) : value{val} {}
135
136 void operator()(const FieldBuffer& buffer) {
137 if (buffer.length != 1) {
138 throw InvalidInputBufferSize{buffer.length, "for type char"};
139 }
141 }
142};
143//@}
144
145//@{
146/** @name C++ to PostgreSQL mapping for string types */
147template <>
148struct CppToSystemPg<const char*> : PredefinedOid<PredefinedOids::kText> {};
149template <std::size_t N>
150struct CppToSystemPg<char[N]> : PredefinedOid<PredefinedOids::kText> {};
151template <>
152struct CppToSystemPg<std::string> : PredefinedOid<PredefinedOids::kText> {};
153template <>
155};
156template <>
157struct CppToSystemPg<char> : PredefinedOid<PredefinedOids::kChar> {};
158//@}
159
160} // namespace storages::postgres::io
161
162USERVER_NAMESPACE_END