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
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
|
#pragma once
#include <forstio/error.hpp>
#include <forstio/buffer.hpp>
#include "data.hpp"
#include "stream_value.hpp"
namespace saw {
namespace encode {
struct Csv {};
}
namespace impl {
struct csv_helper {
static bool is_whitespace(int8_t ch){
/**
* @TODO supply relevant control characters for checks.
* Newlines are whitespace technically, but also control characters in CSV.
* Contrary to JSON for example.
*/
return ch == '\t' || ch == ' ';
}
static void skip_whitespace(buffer_view& buff){
while(buff.read_composite_length() > 0 && csv_helper::is_whitespace(buff.read())){
buff.read_advance(1u);
}
}
};
template<typename Schema, typename FromDecode>
struct csv_encode {
static_assert(always_false<Schema, FromDecode>, "Case not supported");
};
template<typename T, size_t Dim, typename FromDecode>
struct csv_encode<schema::Array<T,Dim>, FromDecode> {
static_assert(Dim == 1, "Only one dimension is allowed.");
static_assert(!is_array<T>::value, "Array of an array is not allowed.");
static_assert(is_tuple<T>::value || is_struct<T>::value, "Only struct or tuples allowed inside a csv array");
using Schema = schema::Array<T,Dim>;
static error_or<void> encode(const data<Schema, FromDecode>& from, buffer& to){
if constexpr (is_struct<T>::value){
auto eov = csv_encode<T,FromDecode>::encode_header(to);
if(eov.is_error()){
return eov;
}
}
for(data<schema::UInt64> i = 0; i < from.size(); ++i){
auto eov = csv_encode<T,FromDecode>::encode(from.at(i), to);
if(eov.is_error()){
return eov;
}
}
return void_t{};
}
};
template<typename... V, string_literal... K, typename FromDecode>
struct csv_encode<schema::Struct<schema::Member<V,K>...>, FromDecode> {
using Schema = schema::Struct<schema::Member<V,K>...>;
template<size_t i>
static error_or<void> encode_header_i(buffer& to){
// Encode string
//
constexpr auto str_view = parameter_key_pack_type<i, K...>::literal;
for(auto& iter : str_view.view()){
auto eov = stream_value<schema::Int8>::encode(iter, to);
if(eov.is_error()){
return eov;
}
}
// Go to next string
if constexpr ( (i+1) < sizeof...(K)){
/**
* Replace this with col separator
*/
constexpr std::string_view lit = ",";
for(int8_t iter : lit){
auto eov = stream_value<schema::Int8>::encode(iter, to);
if(eov.is_error()){
return eov;
}
}
return encode_header_i<i+1>(to);
}
{
/**
* Replace this with row separator
*/
constexpr std::string_view lit = "\n";
for(int8_t iter : lit){
auto eov = stream_value<schema::Int8>::encode(iter, to);
if ( eov.is_error()){
return eov;
}
}
}
return make_void();
}
static error_or<void> encode_header(buffer& to){
if constexpr (sizeof...(V) > 0u){
return encode_header_i<0u>(to);
}
return make_void();
}
template<size_t i>
static error_or<void> encode_i(const data<Schema, FromDecode>& from, buffer& to){
constexpr auto str_view = parameter_key_pack_type<i,K...>::literal;
{
auto eov = csv_encode<typename parameter_pack_type<i,V...>::type, FromDecode>::encode(from.template get<str_view>(), to);
if(eov.is_error()){
return eov;
}
}
if constexpr ( (i+1) < sizeof...(K)){
/**
* Replace this with col separator
*/
constexpr std::string_view lit = ",";
for(int8_t iter : lit){
auto eov = stream_value<schema::Int8>::encode(iter, to);
if(eov.is_error()){
return eov;
}
}
return encode_i<i+1>(from, to);
}
{
/**
* Replace this with row separator
*/
constexpr std::string_view lit = "\r\n";
for(int8_t iter : lit){
auto eov = stream_value<schema::Int8>::encode(iter, to);
if ( eov.is_error()){
return eov;
}
}
}
return make_void();
}
static error_or<void> encode(const data<Schema, FromDecode>& from, buffer& to){
return encode_i<0>(from, to);
}
};
template<typename FromDecode>
struct csv_encode<schema::String, FromDecode> {
using Schema = schema::String;
static error_or<void> encode(const data<Schema, FromDecode>& from, buffer& to){
for(data<schema::UInt64> i = 0; i < from.size(); ++i){
auto eov = stream_value<schema::Int8>::encode(from.at(i.get()), to);
if(eov.is_error()){
return eov;
}
}
return make_void();
}
};
template<class T, size_t N, typename FromDecode>
struct csv_encode<schema::Primitive<T,N>, FromDecode> {
using Schema = schema::Primitive<T,N>;
static error_or<void> encode(const data<Schema, FromDecode>& from, buffer& to){
std::string to_str;
try {
to_str = std::to_string(from.get());
}catch(const std::exception& ){
return make_error<err::out_of_memory>();
}
for(auto iter : to_str){
auto eov = stream_value<schema::Int8>::encode(iter, to);
if(eov.is_error()){
return eov;
}
}
return make_void();
}
};
template<typename Schema, typename FromDecode>
struct csv_decode {
static_assert(always_false<Schema, FromDecode>, "Case not supported");
};
template<typename T, size_t Dim, typename FromDecode>
struct csv_decode<schema::Array<T,Dim>, FromDecode> {
static_assert(Dim == 1, "Only one dimension is allowed.");
static_assert(!is_array<T>::value, "Array of an array is not allowed.");
static_assert(is_tuple<T>::value || is_struct<T>::value, "Only struct or tuples allowed inside a csv array");
using Schema = schema::Array<T,Dim>;
static error_or<void> decode(data<Schema, encode::Csv>& from, data<Schema, FromDecode>& to){
buffer_view view{from.get_buffer()};
if constexpr (is_struct<T>::value) {
auto eov = csv_decode<T, FromDecode>::check_header(view);
if(eov.is_error()){
return eov;
}
}
uint64_t len{};
return make_error<err::not_implemented>();
}
};
}
template<typename Schema>
class data<Schema, encode::Csv> {
private:
own<buffer> buffer_;
public:
data():
buffer_{heap<ring_buffer>()}
{}
data(own<buffer> buffer__):
buffer_{std::move(buffer__)}
{}
buffer& get_buffer(){
return *buffer_;
}
};
template<typename Schema>
class codec<Schema, encode::Csv> {
static_assert(is_array<Schema>::value, "Only an Array is allowed as a base value");
public:
template<typename FromEncode>
static error_or<void> encode(const data<Schema, FromEncode>& from, data<Schema,encode::Csv>& to){
buffer_view buff_v{to.get_buffer()};
auto eov = impl::csv_encode<Schema, FromEncode>::encode(from, buff_v);
if(eov.is_error()){
return eov;
}
to.get_buffer().write_advance(buff_v.write_offset());
return eov;
}
template<typename ToDecode>
static error_or<void> decode(data<Schema,encode::Csv>& from, data<Schema, ToDecode>& to){
auto& buff = from.get_buffer();
buffer_view buff_v{buff};
auto eov = impl::csv_decode<Schema, ToDecode>::decode(buff_v, to);
if(eov.is_error()){
return eov;
}
buff.write_advance(buff_v.write_offset());
return eov;
}
};
}
|
