/
writer.c
359 lines (326 loc) · 9.38 KB
/
writer.c
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
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
/**
* @file de/writer.h
* Serializer for writing values and data into a byte array.
* @ingroup base
*
* @authors Copyright © 2011-2013 Jaakko Keränen <jaakko.keranen@iki.fi>
*
* @par License
* GPL: http://www.gnu.org/licenses/gpl.html
*
* <small>This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version. This program is distributed in the hope that it
* will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
* Public License for more details. You should have received a copy of the GNU
* General Public License along with this program; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA</small>
*/
#include "de/writer.h"
#include "de/memory.h"
#include <string.h>
#include <de/c_wrapper.h>
#ifdef DENG_WRITER_TYPECHECK
# define Writer_TypeCheck(w, code) w->data[w->pos++] = code;
#else
# define Writer_TypeCheck(w, code)
#endif
typedef struct writerfuncs_s {
Writer_Callback_WriteInt8 writeInt8;
Writer_Callback_WriteInt16 writeInt16;
Writer_Callback_WriteInt32 writeInt32;
Writer_Callback_WriteFloat writeFloat;
Writer_Callback_WriteData writeData;
} writerfuncs_t;
struct writer_s
{
byte *data; // The data buffer.
size_t size; // Size of the data buffer.
size_t pos; // Current position in the buffer.
dd_bool isDynamic; // The buffer will be reallocated when needed.
size_t maxDynamicSize; // Zero for unlimited.
dd_bool useCustomFuncs; // Validity checks are skipped (callbacks' responsibility).
writerfuncs_t func; // Callbacks for write operations.
};
static dd_bool Writer_Check(Writer const *writer, size_t len)
{
#ifdef DENG_WRITER_TYPECHECK
// One extra byte for the check code.
if(len) len++;
#endif
DENG_ASSERT(writer);
DENG_ASSERT(writer->data || writer->useCustomFuncs);
if(!writer || (!writer->data && !writer->useCustomFuncs))
return false;
if(writer->useCustomFuncs)
{
// Not our responsibility.
return true;
}
if((int)writer->pos > (int)writer->size - (int)len)
{
// Dynamic buffers will expand.
if(writer->isDynamic && len)
{
Writer *modWriter = (Writer *) writer;
while((int)modWriter->size < (int)writer->pos + (int)len)
{
modWriter->size *= 2;
}
if(writer->maxDynamicSize)
{
modWriter->size = MIN_OF(writer->maxDynamicSize, writer->size);
}
modWriter->data = M_Realloc(writer->data, writer->size);
// OK now?
if((int)writer->pos <= (int)writer->size - (int)len)
return true;
}
App_Log(DE2_LOG_ERROR,
"Writer_Check: Position %lu[+%lu] out of bounds, size=%lu, dynamic=%i.\n",
(unsigned long) writer->pos,
(unsigned long) len,
(unsigned long) writer->size,
writer->isDynamic);
App_FatalError("Writer bounds check failed.");
}
return true;
}
static void Writer_WriteRaw(Writer *writer, void const *buffer, size_t len)
{
memcpy(writer->data + writer->pos, buffer, len);
writer->pos += len;
}
Writer *Writer_NewWithBuffer(byte *buffer, size_t maxLen)
{
Writer *w = M_Calloc(sizeof(Writer));
w->size = maxLen;
w->data = buffer;
return w;
}
Writer *Writer_NewWithDynamicBuffer(size_t maxLen)
{
Writer *w = M_Calloc(sizeof(Writer));
w->isDynamic = true;
w->maxDynamicSize = maxLen;
w->size = 256;
w->data = M_Calloc(w->size);
return w;
}
Writer *Writer_NewWithCallbacks(Writer_Callback_WriteInt8 writeInt8,
Writer_Callback_WriteInt16 writeInt16,
Writer_Callback_WriteInt32 writeInt32,
Writer_Callback_WriteFloat writeFloat,
Writer_Callback_WriteData writeData)
{
Writer *w = M_Calloc(sizeof(Writer));
w->useCustomFuncs = true;
w->func.writeInt8 = writeInt8;
w->func.writeInt16 = writeInt16;
w->func.writeInt32 = writeInt32;
w->func.writeFloat = writeFloat;
w->func.writeData = writeData;
return w;
}
void Writer_Delete(Writer *writer)
{
if(writer->isDynamic)
{
// The buffer was allocated by us.
M_Free(writer->data);
}
M_Free(writer);
}
size_t Writer_Size(Writer const *writer)
{
if(!writer) return 0;
return writer->pos;
}
size_t Writer_TotalBufferSize(Writer const *writer)
{
if(!writer) return 0;
return writer->size;
}
size_t Writer_BytesLeft(Writer const *writer)
{
return Writer_TotalBufferSize(writer) - Writer_Size(writer);
}
byte const *Writer_Data(Writer const *writer)
{
if(Writer_Check(writer, 0))
{
return writer->data;
}
return 0;
}
void Writer_SetPos(Writer *writer, size_t newPos)
{
if(!writer || writer->useCustomFuncs) return;
writer->pos = newPos;
Writer_Check(writer, 0);
}
void Writer_WriteChar(Writer *writer, char v)
{
if(!Writer_Check(writer, 1)) return;
if(!writer->useCustomFuncs)
{
Writer_TypeCheck(writer, WTCC_CHAR);
((int8_t *)writer->data)[writer->pos++] = v;
}
else
{
assert(writer->func.writeInt8);
writer->func.writeInt8(writer, v);
}
}
void Writer_WriteByte(Writer *writer, byte v)
{
if(!Writer_Check(writer, 1)) return;
if(!writer->useCustomFuncs)
{
Writer_TypeCheck(writer, WTCC_BYTE);
writer->data[writer->pos++] = v;
}
else
{
assert(writer->func.writeInt8);
writer->func.writeInt8(writer, v);
}
}
void Writer_WriteInt16(Writer *writer, int16_t v)
{
if(Writer_Check(writer, 2))
{
if(!writer->useCustomFuncs)
{
int16_t foreign = LittleEndianByteOrder_ToForeignInt16(v);
Writer_TypeCheck(writer, WTCC_INT16);
Writer_WriteRaw(writer, &foreign, 2);
}
else
{
assert(writer->func.writeInt16);
writer->func.writeInt16(writer, v);
}
}
}
void Writer_WriteUInt16(Writer *writer, uint16_t v)
{
if(Writer_Check(writer, 2))
{
if(!writer->useCustomFuncs)
{
uint16_t foreign = LittleEndianByteOrder_ToForeignUInt16(v);
Writer_TypeCheck(writer, WTCC_UINT16);
Writer_WriteRaw(writer, &foreign, 2);
}
else
{
assert(writer->func.writeInt16);
writer->func.writeInt16(writer, v);
}
}
}
void Writer_WriteInt32(Writer *writer, int32_t v)
{
if(Writer_Check(writer, 4))
{
if(!writer->useCustomFuncs)
{
int32_t foreign = LittleEndianByteOrder_ToForeignInt32(v);
Writer_TypeCheck(writer, WTCC_INT32);
Writer_WriteRaw(writer, &foreign, 4);
}
else
{
assert(writer->func.writeInt32);
writer->func.writeInt32(writer, v);
}
}
}
void Writer_WriteUInt32(Writer *writer, uint32_t v)
{
if(Writer_Check(writer, 4))
{
if(!writer->useCustomFuncs)
{
uint32_t foreign = LittleEndianByteOrder_ToForeignUInt32(v);
Writer_TypeCheck(writer, WTCC_UINT32);
Writer_WriteRaw(writer, &foreign, 4);
}
else
{
assert(writer->func.writeInt32);
writer->func.writeInt32(writer, v);
}
}
}
void Writer_WriteFloat(Writer *writer, float v)
{
if(Writer_Check(writer, 4))
{
if(!writer->useCustomFuncs)
{
float foreign = LittleEndianByteOrder_ToForeignFloat(v);
Writer_TypeCheck(writer, WTCC_FLOAT);
Writer_WriteRaw(writer, &foreign, 4);
}
else
{
assert(writer->func.writeFloat);
writer->func.writeFloat(writer, v);
}
}
}
void Writer_Write(Writer *writer, void const *buffer, size_t len)
{
if(!len) return;
if(Writer_Check(writer, len))
{
if(!writer->useCustomFuncs)
{
Writer_TypeCheck(writer, WTCC_BLOCK);
Writer_WriteRaw(writer, buffer, len);
}
else
{
assert(writer->func.writeData);
writer->func.writeData(writer, buffer, len);
}
}
}
void Writer_WritePackedUInt16(Writer *writer, uint16_t v)
{
DENG_ASSERT(!(v & 0x8000));
if(v & 0x8000)
{
App_Log(DE2_LOG_ERROR,
"Writer_WritePackedUInt16: Cannot write %i (%x).\n", v, v);
return;
}
// Can the number be represented with 7 bits?
if(v < 0x80)
{
Writer_WriteByte(writer, (dbyte) v);
}
else
{
Writer_WriteByte(writer, 0x80 | (v & 0x7f));
Writer_WriteByte(writer, v >> 7); // Highest bit is lost.
}
}
void Writer_WritePackedUInt32(Writer *writer, uint32_t l)
{
while(l >= 0x80)
{
// Write the lowest 7 bits, and set the high bit to indicate that
// at least one more byte will follow.
Writer_WriteByte(writer, 0x80 | (l & 0x7f));
l >>= 7;
}
// Write the last byte, with the high bit clear.
Writer_WriteByte(writer, l);
}