1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
|
#pragma once
#include "util/endian.hpp"
#include <boost/pfr/core.hpp>
#include <cassert>
#include <concepts>
#include <cstddef>
#include <cstdint>
#include <cstdio>
#include <cstring>
#include <fcntl.h>
#include <stdexcept>
#include <string>
#include <unistd.h>
namespace io {
template <class T, class K>
concept custom_write = requires(T t, K &k) {
{ t.write(k) } -> std::same_as<ssize_t>;
};
template <class T, class K>
concept custom_read = requires(T& t, K &k) {
{ t.read(k) } -> std::same_as<ssize_t>;
};
template <class T>
concept container = requires(T& t) {
{ t.data() };
{ t.size() };
{ t.begin() };
{ t.end() };
};
class file_io {
int fd;
public:
file_io(int fd)
: fd(fd)
{
}
struct eof {};
file_io(std::string filename)
: fd(open(filename.c_str(), O_RDWR))
{
if (fd < 0)
throw std::runtime_error(strerror(errno));
}
//~file_io()
//{
// ::close(fd);
//}
ssize_t read_data(char* buf, size_t nbytes)
{
auto bytes = ::read(fd, buf, nbytes);
if (bytes == EOF) {
throw eof{};
}
assert(bytes >= 0);
return bytes;
}
ssize_t write_data(const char* buf, size_t nbytes)
{
auto bytes = ::write(fd, buf, nbytes);
if (bytes == EOF) {
throw eof{};
}
assert(bytes >= 0);
return bytes;
}
};
template <container T>
class buffered_io {
size_t cursor = 0;
T& buffer;
public:
buffered_io(T& buffer)
: buffer(buffer)
{
}
ssize_t read_data(char* buf, size_t nbytes)
{
auto bytes = nbytes > (buffer.size() - cursor) ? (buffer.size() - cursor) : nbytes;
memcpy(buf, buffer.data() + cursor, bytes);
cursor += bytes;
return bytes;
}
ssize_t write_data(const char* buf, size_t nbytes)
{
buffer.insert(buffer.end(), buf, buf + nbytes);
return nbytes;
}
};
template <class I>
class serialized_io {
I io;
public:
serialized_io(I io)
: io(io)
{
}
template <std::integral T>
ssize_t read(T& f)
{
auto bytes = io.read_data(reinterpret_cast<char*>(&f), sizeof(T));
f = to_little(f);
return bytes;
}
template <std::floating_point T>
ssize_t read(T& f)
{
auto bytes = io.read_data(reinterpret_cast<char*>(&f), sizeof(T));
//f = to_little(f);
return bytes;
}
ssize_t read(std::string& f)
{
// FIXME: varint
uint8_t size;
auto bytes = read(size);
f.resize(size);
bytes += io.read_data(f.data(), size);
return bytes;
}
template <custom_read<serialized_io<I>> T>
ssize_t read(T& f)
{
return f.read(*this);
}
template <container T>
ssize_t read(T& f)
{
return io.read_data(reinterpret_cast<char*>(f.data()), f.size() * sizeof(typename T::value_type));
}
template <class T>
ssize_t read(T& f)
{
ssize_t bytes = 0;
boost::pfr::for_each_field(f, [this, &bytes](auto& field) {
bytes += read(field);
});
return bytes;
}
template <std::integral T>
ssize_t write(const T f)
{
auto x = to_little(f);
return io.write_data(reinterpret_cast<const char*>(&x), sizeof(T));
}
template <std::floating_point T>
ssize_t write(const T f)
{
// FIXME: endianness
return io.write_data(reinterpret_cast<const char*>(&f), sizeof(T));
}
ssize_t write(const std::string f)
{
// FIXME: varint
auto bytes = write(uint8_t(f.size()));
bytes += io.write_data(f.c_str(), f.size());
return bytes;
}
template <container T>
ssize_t write(const T f)
{
return io.write_data(reinterpret_cast<const char*>(f.data()), f.size() * sizeof(typename T::value_type));
}
template <custom_write<serialized_io<I>> T>
ssize_t write(T f)
{
return f.write(*this);
}
template <class T>
ssize_t write(const T f)
{
ssize_t bytes = 0;
boost::pfr::for_each_field(f, [this, &bytes](auto field) {
bytes += write(field);
});
return bytes;
}
};
using serialized_file = serialized_io<file_io>;
}
|
