DAW JSON Link
Loading...
Searching...
No Matches
daw_json_parse_string_quote.h
Go to the documentation of this file.
1// Copyright (c) Darrell Wright
2//
3// Distributed under the Boost Software License, Version 1.0. (See accompanying
4// file LICENSE or copy at http://www.boost.org/LICENSE_1_0.txt)
5//
6// Official repository: https://github.com/beached/daw_json_link
7//
8
9#pragma once
10
11#include "version.h"
12
13#include "daw_json_assert.h"
14#include "daw_not_const_ex_functions.h"
15
16#include <daw/daw_traits.h>
17#include <daw/daw_uint_buffer.h>
18
19#include <cstddef>
20#include <type_traits>
21
22namespace daw::json {
23 inline namespace DAW_JSON_VER {
24 namespace json_details::string_quote {
25 template<std::size_t N, char c>
26 inline constexpr UInt8 test_at_byte( UInt64 b ) {
27 auto const lhs = b & ( 0xFF_u64 << ( N * 8U ) );
28 using rhs = daw::constant<to_uint64( static_cast<unsigned char>( c ) )
29 << ( N * 8U )>;
30 return to_uint8( not( lhs - rhs::value ) );
31 }
32
33 template<std::size_t N, char c>
34 DAW_ATTRIB_INLINE constexpr UInt8 test_at_byte( UInt32 b ) {
35 auto const lhs = b & ( 0xFF_u32 << ( N * 8U ) );
36 using rhs = daw::constant<to_uint32( static_cast<unsigned char>( c ) )
37 << ( N * 8U )>;
38 return to_uint8( not( lhs - rhs::value ) );
39 }
40
41 template<typename CharT>
42 DAW_ATTRIB_NONNULL( )
43 inline constexpr void skip_to_first8( CharT *&first, CharT *const last ) {
44 bool keep_going = last - first >= 8;
45 while( keep_going ) {
46 auto buff = daw::to_uint64_buffer( first );
47 auto const q7 = test_at_byte<7U, '"'>( buff );
48 auto const q6 = test_at_byte<6U, '"'>( buff );
49 auto const q5 = test_at_byte<5U, '"'>( buff );
50 auto const q4 = test_at_byte<4U, '"'>( buff );
51 auto const q3 = test_at_byte<3U, '"'>( buff );
52 auto const q2 = test_at_byte<2U, '"'>( buff );
53 auto const q1 = test_at_byte<1U, '"'>( buff );
54 auto const q0 = test_at_byte<0U, '"'>( buff );
55 auto const s7 = test_at_byte<7U, '\\'>( buff );
56 auto const s6 = test_at_byte<6U, '\\'>( buff );
57 auto const s5 = test_at_byte<5U, '\\'>( buff );
58 auto const s4 = test_at_byte<4U, '\\'>( buff );
59 auto const s3 = test_at_byte<3U, '\\'>( buff );
60 auto const s2 = test_at_byte<2U, '\\'>( buff );
61 auto const s1 = test_at_byte<1U, '\\'>( buff );
62 auto const s0 = test_at_byte<0U, '\\'>( buff );
63
64 keep_going = not( q0 | q1 | q2 | q3 | q4 | q5 | q6 | q7 | s0 | s1 |
65 s2 | s3 | s4 | s5 | s6 | s7 );
66 keep_going = keep_going & static_cast<bool>( last - first >= 16 );
67 first += static_cast<int>( keep_going ) * 8;
68 }
69 first -= *( first - 1 ) == '\\' ? 1 : 0;
70 }
71
72 template<typename CharT>
73 DAW_ATTRIB_NONNULL( )
74 inline constexpr void skip_to_first4( CharT *&first, CharT *const last ) {
75 bool keep_going = last - first >= 4;
76 while( keep_going ) {
77 // Need to look for escapes as this is fast path
78 auto buff = daw::to_uint32_buffer( first );
79 auto const q3 = test_at_byte<3U, '"'>( buff );
80 auto const q2 = test_at_byte<2U, '"'>( buff );
81 auto const q1 = test_at_byte<1U, '"'>( buff );
82 auto const q0 = test_at_byte<0U, '"'>( buff );
83 auto const s3 = test_at_byte<3U, '\\'>( buff );
84 auto const s2 = test_at_byte<2U, '\\'>( buff );
85 auto const s1 = test_at_byte<1U, '\\'>( buff );
86 auto const s0 = test_at_byte<0U, '\\'>( buff );
87 keep_going = not( q0 | q1 | q2 | q3 | s0 | s1 | s2 | s3 );
88 keep_going = keep_going & static_cast<bool>( last - first >= 8 );
89 first += static_cast<int>( keep_going ) * 4;
90 }
91 first -= *( first - 1 ) == '\\' ? 1 : 0;
92 }
93
94 namespace string_quote_parser {
95 template<typename ParseState>
96 [[nodiscard]] static constexpr std::size_t
97 parse_nq_uncheck( ParseState &parse_state ) {
98 using CharT = typename ParseState::CharT;
99 std::ptrdiff_t need_slow_path = -1;
100 CharT *first = parse_state.first;
101 CharT *const last = parse_state.last;
102 // This is a logic error to happen.
103 // daw_json_assert_weak( first != '"', "Unexpected quote", parse_state
104 // );
105 if constexpr( daw::traits::not_same_v<typename ParseState::exec_tag_t,
106 constexpr_exec_tag> ) {
107 first = mem_skip_until_end_of_string<true>(
108 ParseState::exec_tag, first, last, need_slow_path );
109 } else {
110
111 {
112 auto const sz = last - first;
113 if( sz >= 8 ) {
114 skip_to_first8( first, last );
115 } else if( sz >= 4 ) {
116 skip_to_first4( first, last );
117 }
118 }
119 while( *first != '"' ) {
120 while( []( char c ) DAW_JSON_CPP23_STATIC_CALL_OP {
121 return ( c != '"' ) & ( c != '\\' );
122 }( *first ) ) {
123 ++first;
124 }
125 if( *first == '\\' ) {
126 if( need_slow_path < 0 ) {
127 need_slow_path = first - parse_state.first;
128 }
129 first += 2;
130 } else {
131 break;
132 }
133 }
134 }
135 parse_state.first = first;
136 return static_cast<std::size_t>( need_slow_path );
137 }
138
139 template<typename ParseState>
140 [[nodiscard]] static constexpr std::size_t
141 parse_nq_check( ParseState &parse_state ) {
142
143 using CharT = typename ParseState::CharT;
144 std::ptrdiff_t need_slow_path = -1;
145 CharT *first = parse_state.first;
146 CharT *const last = parse_state.class_last;
147 if constexpr( daw::traits::not_same_v<typename ParseState::exec_tag_t,
148 constexpr_exec_tag> ) {
149 first = mem_skip_until_end_of_string<false>(
150 ParseState::exec_tag, first, last, need_slow_path );
151 } else {
152 if constexpr( not ParseState::exclude_special_escapes ) {
153 if( CharT *const l = parse_state.last; l - first >= 8 ) {
154 skip_to_first8( first, l );
155 } else if( last - first >= 4 ) {
156 skip_to_first4( first, l );
157 }
158 }
159 if constexpr( ParseState::is_zero_terminated_string ) {
160 if constexpr( ParseState::exclude_special_escapes ) {
161 while( *first != '\0' ) {
162 char c = *first;
163 daw_json_ensure( static_cast<unsigned char>( c ) >= 0x20U,
164 ErrorReason::InvalidString, parse_state );
165 if( c == '\\' ) {
166 daw_json_ensure( last - first > 1,
167 ErrorReason::InvalidString, parse_state );
168 if( need_slow_path < 0 ) {
169 need_slow_path = first - parse_state.first;
170 }
171 ++first;
172 c = *first;
173 switch( c ) {
174 case '"':
175 case '\\':
176 case '/':
177 case 'b':
178 case 'f':
179 case 'n':
180 case 'r':
181 case 't':
182 case 'u':
183 break;
184 default:
185 daw_json_error( ErrorReason::InvalidString, parse_state );
186 }
187 } else if( c == '"' ) {
188 break;
189 }
190 ++first;
191 }
192 } else {
193 while( ( *first != 0 ) & ( *first != '"' ) ) {
194 while( ( *first != 0 ) & ( *first != '"' ) &
195 ( *first != '\\' ) ) {
196 ++first;
197 }
198
199 if( ( ( *first != 0 ) & ( *first == '\\' ) ) ) {
200 if( need_slow_path < 0 ) {
201 need_slow_path = first - parse_state.first;
202 }
203 first += 2;
204 } else {
205 break;
206 }
207 }
208 }
209 } else {
210 if constexpr( ParseState::exclude_special_escapes ) {
211 while( first < last ) {
212 char c = *first;
213 daw_json_ensure( static_cast<unsigned char>( c ) >= 0x20U,
214 ErrorReason::InvalidString, parse_state );
215 if( c == '\\' ) {
216 daw_json_ensure( last - first > 1,
217 ErrorReason::InvalidString, parse_state );
218 if( need_slow_path < 0 ) {
219 need_slow_path = first - parse_state.first;
220 }
221 ++first;
222 c = *first;
223 switch( c ) {
224 case '"':
225 case '\\':
226 case '/':
227 case 'b':
228 case 'f':
229 case 'n':
230 case 'r':
231 case 't':
232 case 'u':
233 break;
234 default:
235 daw_json_error( ErrorReason::InvalidString, parse_state );
236 }
237 } else if( c == '"' ) {
238 break;
239 }
240 ++first;
241 }
242 } else {
243 while( first < last and *first != '"' ) {
244 while( first < last and
245 ( ( *first != '"' ) & ( *first != '\\' ) ) ) {
246 ++first;
247 }
248
249 if( first < last and *first == '\\' ) {
250 if( need_slow_path < 0 ) {
251 need_slow_path = first - parse_state.first;
252 }
253 first += 2;
254 } else {
255 break;
256 }
257 }
258 }
259 }
260 }
261 if constexpr( ParseState::is_zero_terminated_string ) {
262 daw_json_assert_weak( *first == '"', ErrorReason::InvalidString,
263 parse_state );
264 } else {
265 daw_json_assert_weak( first < last and *first == '"',
266 ErrorReason::InvalidString, parse_state );
267 }
268 parse_state.first = first;
269 return static_cast<std::size_t>( need_slow_path );
270 }
271
272 template<typename ParseState>
273 [[nodiscard]] DAW_ATTRIB_FLATTEN static constexpr std::size_t
274 parse_nq( ParseState &parse_state ) {
275 if constexpr( ParseState::is_unchecked_input ) {
276 return parse_nq_uncheck( parse_state );
277 } else {
278 return parse_nq_check( parse_state );
279 }
280 }
281 } // namespace string_quote_parser
282 } // namespace json_details::string_quote
283 } // namespace DAW_JSON_VER
284} // namespace daw::json
daw_json_assert.h
daw_json_assert_weak
#define daw_json_assert_weak(Bool,...)
Assert that Bool is true when in Checked Input mode If false pass rest of args to daw_json_error.
Definition daw_json_assert.h:162
daw_json_ensure
#define daw_json_ensure(Bool,...)
Ensure that Bool is true. If false pass rest of args to daw_json_error.
Definition daw_json_assert.h:153
DAW_JSON_CPP23_STATIC_CALL_OP
#define DAW_JSON_CPP23_STATIC_CALL_OP
Definition daw_json_switches.h:200
daw_not_const_ex_functions.h
daw::json::anonymous_namespace{daw_json_assert.h}::daw_json_error
DAW_ATTRIB_NOINLINE void daw_json_error(ErrorReason reason)
Definition daw_json_assert.h:76
daw::json
Customization point traits.
Definition daw_container_traits.h:22
daw::json::constexpr_exec_tag
Definition daw_json_exec_modes.h:17
DAW_JSON_VER
#define DAW_JSON_VER
The version string used in namespace definitions. Must be a valid namespace name.
Definition version.h:20
Generated by doxygen 1.9.8