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comparison Implab/Formats/JSON/JSONWriter.cs @ 163:419aa51b04fd ref20160224

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JSON moved to Formats namespace Working in RegularDFA
author cin
date Wed, 24 Feb 2016 20:12:52 +0300
parents
children c32688129f14
comparison
equal deleted inserted replaced
162:0526412bbb26 163:419aa51b04fd
1 using System;
2 using System.Collections.Generic;
3 using System.IO;
4 using System.Globalization;
5 using System.Diagnostics;
6
7 namespace Implab.JSON {
8 public class JSONWriter {
9 struct Context {
10 public bool needComma;
11 public JSONElementContext element;
12 }
13 Stack<Context> m_contextStack = new Stack<Context>();
14 Context m_context;
15
16 const int BUFFER_SIZE = 64;
17
18 TextWriter m_writer;
19 readonly bool m_indent = true;
20 readonly int m_indentSize = 4;
21 readonly char[] m_buffer = new char[BUFFER_SIZE];
22 int m_bufferPos;
23
24 static readonly char [] _hex = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
25 static readonly char [] _escapeBKS,
26 _escapeFWD,
27 _escapeCR,
28 _escapeNL,
29 _escapeTAB,
30 _escapeBSLASH,
31 _escapeQ;
32
33 static JSONWriter() {
34 _escapeBKS = "\\b".ToCharArray();
35 _escapeFWD = "\\f".ToCharArray();
36 _escapeCR = "\\r".ToCharArray();
37 _escapeNL = "\\n".ToCharArray();
38 _escapeTAB = "\\t".ToCharArray();
39 _escapeBSLASH = "\\\\".ToCharArray();
40 _escapeQ = "\\\"".ToCharArray();
41 }
42
43 public JSONWriter(TextWriter writer) {
44 Safe.ArgumentNotNull(writer, "writer");
45 m_writer = writer;
46 }
47
48 public JSONWriter(TextWriter writer, bool indent) {
49 Safe.ArgumentNotNull(writer, "writer");
50
51 m_writer = writer;
52 m_indent = indent;
53 }
54
55 void WriteIndent() {
56 if (m_indent) {
57 var indent = new char[m_contextStack.Count * m_indentSize + 1];
58 indent[0] = '\n';
59 for (int i = 1; i < indent.Length; i++)
60 indent[i] = ' ';
61 m_writer.Write(new String(indent));
62 } else {
63 m_writer.Write(' ');
64 }
65 }
66
67 void WriteMemberName(string name) {
68 Safe.ArgumentNotEmpty(name, "name");
69 if (m_context.element != JSONElementContext.Object)
70 OperationNotApplicable("WriteMember");
71 if (m_context.needComma)
72 m_writer.Write(",");
73
74 WriteIndent();
75 m_context.needComma = true;
76 Write(name);
77 m_writer.Write(" : ");
78 }
79
80 public void WriteValue(string name, string value) {
81 WriteMemberName(name);
82 Write(value);
83 }
84
85 public void WriteValue(string name, bool value) {
86 WriteMemberName(name);
87 Write(value);
88 }
89
90 public void WriteValue(string name, double value) {
91 WriteMemberName(name);
92 Write(value);
93 }
94
95 public void WriteValue(string value) {
96 if (m_context.element == JSONElementContext.Array) {
97
98 if (m_context.needComma)
99 m_writer.Write(",");
100 WriteIndent();
101 m_context.needComma = true;
102
103 Write(value);
104 } else if (m_context.element == JSONElementContext.None) {
105 Write(value);
106 m_context.element = JSONElementContext.Closed;
107 } else {
108 OperationNotApplicable("WriteValue");
109 }
110 }
111
112 public void WriteValue(bool value) {
113 if (m_context.element == JSONElementContext.Array) {
114
115 if (m_context.needComma)
116 m_writer.Write(",");
117 WriteIndent();
118 m_context.needComma = true;
119
120 Write(value);
121 } else if (m_context.element == JSONElementContext.None) {
122 Write(value);
123 m_context.element = JSONElementContext.Closed;
124 } else {
125 OperationNotApplicable("WriteValue");
126 }
127 }
128
129 public void WriteValue(double value) {
130 if (m_context.element == JSONElementContext.Array) {
131
132 if (m_context.needComma)
133 m_writer.Write(",");
134 WriteIndent();
135 m_context.needComma = true;
136
137 Write(value);
138 } else if (m_context.element == JSONElementContext.None) {
139 Write(value);
140 m_context.element = JSONElementContext.Closed;
141 } else {
142 OperationNotApplicable("WriteValue");
143 }
144 }
145
146 public void BeginObject() {
147 if (m_context.element != JSONElementContext.None && m_context.element != JSONElementContext.Array)
148 OperationNotApplicable("BeginObject");
149 if (m_context.needComma)
150 m_writer.Write(",");
151
152 WriteIndent();
153
154 m_context.needComma = true;
155
156 m_contextStack.Push(m_context);
157
158 m_context = new Context { element = JSONElementContext.Object, needComma = false };
159 m_writer.Write("{");
160 }
161
162 public void BeginObject(string name) {
163 WriteMemberName(name);
164
165 m_contextStack.Push(m_context);
166
167 m_context = new Context { element = JSONElementContext.Object, needComma = false };
168 m_writer.Write("{");
169 }
170
171 public void EndObject() {
172 if (m_context.element != JSONElementContext.Object)
173 OperationNotApplicable("EndObject");
174
175 m_context = m_contextStack.Pop();
176 if (m_contextStack.Count == 0)
177 m_context.element = JSONElementContext.Closed;
178 WriteIndent();
179 m_writer.Write("}");
180 }
181
182 public void BeginArray() {
183 if (m_context.element != JSONElementContext.None && m_context.element != JSONElementContext.Array)
184 throw new InvalidOperationException();
185 if (m_context.needComma) {
186 m_writer.Write(",");
187
188 }
189 m_context.needComma = true;
190
191 WriteIndent();
192 m_contextStack.Push(m_context);
193 m_context = new Context { element = JSONElementContext.Array, needComma = false };
194 m_writer.Write("[");
195 }
196
197 public void BeginArray(string name) {
198 WriteMemberName(name);
199
200 m_contextStack.Push(m_context);
201
202 m_context = new Context { element = JSONElementContext.Array, needComma = false };
203 m_writer.Write("[");
204 }
205
206 public void EndArray() {
207 if (m_context.element != JSONElementContext.Array)
208 OperationNotApplicable("EndArray");
209
210 m_context = m_contextStack.Pop();
211 if (m_contextStack.Count == 0)
212 m_context.element = JSONElementContext.Closed;
213 WriteIndent();
214 m_writer.Write("]");
215 }
216
217 void Write(bool value) {
218 m_writer.Write(value ? "true" : "false");
219 }
220
221 void FlushBuffer() {
222 if (m_bufferPos > 0) {
223 m_writer.Write(m_buffer, 0, m_bufferPos);
224 m_bufferPos = 0;
225 }
226 }
227
228 void Write(string value) {
229 if (value == null) {
230 m_writer.Write("null");
231 return;
232 }
233
234 Debug.Assert(m_bufferPos == 0);
235
236 var chars = value.ToCharArray();
237 m_buffer[m_bufferPos++] = '"';
238
239 // Analysis disable once ForCanBeConvertedToForeach
240 for (int i = 0; i < chars.Length; i++) {
241 var ch = chars[i];
242
243 char[] escapeSeq;
244
245 switch (ch) {
246 case '\b':
247 escapeSeq = _escapeBKS;
248 break;
249 case '\f':
250 escapeSeq = _escapeFWD;
251 break;
252 case '\r':
253 escapeSeq = _escapeCR;
254 break;
255 case '\n':
256 escapeSeq = _escapeNL;
257 break;
258 case '\t':
259 escapeSeq = _escapeTAB;
260 break;
261 case '\\':
262 escapeSeq = _escapeBSLASH;
263 break;
264 case '"':
265 escapeSeq = _escapeQ;
266 break;
267 default:
268 if (ch < 0x20) {
269 if (m_bufferPos + 6 > BUFFER_SIZE)
270 FlushBuffer();
271
272 m_buffer[m_bufferPos++] = '\\';
273 m_buffer[m_bufferPos++] = 'u';
274 m_buffer[m_bufferPos++] = '0';
275 m_buffer[m_bufferPos++] = '0';
276 m_buffer[m_bufferPos++] = _hex[ch >> 4 & 0xf];
277 m_buffer[m_bufferPos++] = _hex[ch & 0xf];
278
279 } else {
280 if (m_bufferPos >= BUFFER_SIZE)
281 FlushBuffer();
282 m_buffer[m_bufferPos++] = ch;
283 }
284 continue;
285 }
286
287 if (m_bufferPos + escapeSeq.Length > BUFFER_SIZE)
288 FlushBuffer();
289
290 Array.Copy(escapeSeq, 0, m_buffer, m_bufferPos, escapeSeq.Length);
291 m_bufferPos += escapeSeq.Length;
292
293 }
294
295 if (m_bufferPos >= BUFFER_SIZE)
296 FlushBuffer();
297
298 m_buffer[m_bufferPos++] = '"';
299
300 FlushBuffer();
301 }
302
303 void Write(double value) {
304 if (double.IsNaN(value))
305 Write("NaN");
306 else if (double.IsNegativeInfinity(value))
307 Write("-Infinity");
308 else if (double.IsPositiveInfinity(value))
309 Write("Infinity");
310 else
311 m_writer.Write(value.ToString(CultureInfo.InvariantCulture));
312 }
313
314 void OperationNotApplicable(string opName) {
315 throw new InvalidOperationException(String.Format("The operation '{0}' isn't applicable in the context of '{1}'", opName, m_context.element ));
316 }
317
318 }
319 }