-
-
Notifications
You must be signed in to change notification settings - Fork 31
/
reader.c
328 lines (297 loc) · 8.23 KB
/
reader.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
/**
* @file src/reader.c
* Deserializer for reading values and data from 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/reader.h"
#include "de/memory.h"
#include <string.h>
#include <de/c_wrapper.h>
#ifdef DENG_WRITER_TYPECHECK
# include "de/writer.h"
# define Reader_TypeCheck(r, code) if(r->data[r->pos++] != code) DENG_ASSERT(!code);
#else
# define Reader_TypeCheck(r, code)
#endif
#define Reader_16(reader) ( (uint16_t) (Reader_8(reader, 0) | Reader_8(reader, 8)) )
#define Reader_32(reader) ( Reader_8(reader, 0) | Reader_8(reader, 8) | \
Reader_8(reader, 16) | Reader_8(reader, 24) )
typedef struct readerfuncs_s {
Reader_Callback_ReadInt8 readInt8;
Reader_Callback_ReadInt16 readInt16;
Reader_Callback_ReadInt32 readInt32;
Reader_Callback_ReadFloat readFloat;
Reader_Callback_ReadData readData;
} readerfuncs_t;
struct reader_s
{
byte const *data; // The data buffer.
size_t size; // Size of the data buffer.
size_t pos; // Current position in the buffer.
dd_bool useCustomFuncs;
readerfuncs_t func;
};
static uint32_t Reader_8(Reader *reader, int shift)
{
return reader->data[reader->pos++] << shift;
}
static dd_bool Reader_Check(Reader const *reader, size_t len)
{
#ifdef DENG_WRITER_TYPECHECK
// One byte for the code.
if(len) len++;
#endif
DENG_ASSERT(reader);
DENG_ASSERT(reader->data || reader->useCustomFuncs);
if(!reader || (!reader->data && !reader->useCustomFuncs))
return false;
if(reader->useCustomFuncs)
{
// Not our responsibility.
return true;
}
if(reader->pos > reader->size - len)
{
App_Log(DE2_LOG_ERROR,
"Reader_Check: Position %lu[+%lu] out of bounds, size=%lu.\n",
(unsigned long) reader->pos,
(unsigned long) len,
(unsigned long) reader->size);
App_FatalError("Reader bounds check failed.");
}
return true;
}
Reader *Reader_NewWithBuffer(byte const *buffer, size_t len)
{
Reader *rd = M_Calloc(sizeof(Reader));
rd->size = len;
rd->data = buffer;
return rd;
}
Reader *Reader_NewWithCallbacks(Reader_Callback_ReadInt8 readInt8,
Reader_Callback_ReadInt16 readInt16,
Reader_Callback_ReadInt32 readInt32,
Reader_Callback_ReadFloat readFloat,
Reader_Callback_ReadData readData)
{
Reader *rd = M_Calloc(sizeof(Reader));
rd->useCustomFuncs = true;
rd->func.readInt8 = readInt8;
rd->func.readInt16 = readInt16;
rd->func.readInt32 = readInt32;
rd->func.readFloat = readFloat;
rd->func.readData = readData;
return rd;
}
void Reader_Delete(Reader *reader)
{
M_Free(reader);
}
size_t Reader_Pos(Reader const *reader)
{
if(!reader) return 0;
return reader->pos;
}
size_t Reader_Size(Reader const *reader)
{
if(!reader) return 0;
return reader->size;
}
void Reader_SetPos(Reader *reader, size_t newPos)
{
if(!reader) return;
if(reader->useCustomFuncs) return;
reader->pos = newPos;
Reader_Check(reader, 0);
}
dd_bool Reader_AtEnd(Reader const *reader)
{
Reader_Check(reader, 0);
if(reader->useCustomFuncs) return false;
return reader->pos == reader->size;
}
int8_t Reader_ReadChar(Reader *reader)
{
int8_t result = 0;
if(Reader_Check(reader, 1))
{
if(!reader->useCustomFuncs)
{
Reader_TypeCheck(reader, WTCC_CHAR);
result = ((int8_t *)reader->data)[reader->pos++];
}
else
{
assert(reader->func.readInt8);
result = reader->func.readInt8(reader);
}
}
return result;
}
byte Reader_ReadByte(Reader *reader)
{
byte result = 0;
if(Reader_Check(reader, 1))
{
if(!reader->useCustomFuncs)
{
Reader_TypeCheck(reader, WTCC_BYTE);
result = reader->data[reader->pos++];
}
else
{
assert(reader->func.readInt8);
result = reader->func.readInt8(reader);
}
}
return result;
}
int16_t Reader_ReadInt16(Reader *reader)
{
int16_t result = 0;
if(Reader_Check(reader, 2))
{
if(!reader->useCustomFuncs)
{
Reader_TypeCheck(reader, WTCC_INT16);
result = LittleEndianByteOrder_ToNativeInt16(Reader_16(reader));
}
else
{
assert(reader->func.readInt16);
result = reader->func.readInt16(reader);
}
}
return result;
}
uint16_t Reader_ReadUInt16(Reader *reader)
{
uint16_t result = 0;
if(Reader_Check(reader, 2))
{
if(!reader->useCustomFuncs)
{
Reader_TypeCheck(reader, WTCC_UINT16);
result = LittleEndianByteOrder_ToNativeUInt16(Reader_16(reader));
}
else
{
assert(reader->func.readInt16);
result = reader->func.readInt16(reader);
}
}
return result;
}
int32_t Reader_ReadInt32(Reader *reader)
{
int32_t result = 0;
if(Reader_Check(reader, 4))
{
if(!reader->useCustomFuncs)
{
Reader_TypeCheck(reader, WTCC_INT32);
result = LittleEndianByteOrder_ToNativeInt32(Reader_32(reader));
}
else
{
assert(reader->func.readInt32);
result = reader->func.readInt32(reader);
}
}
return result;
}
uint32_t Reader_ReadUInt32(Reader *reader)
{
uint32_t result = 0;
if(Reader_Check(reader, 4))
{
if(!reader->useCustomFuncs)
{
Reader_TypeCheck(reader, WTCC_UINT32);
result = LittleEndianByteOrder_ToNativeUInt32(Reader_32(reader));
}
else
{
assert(reader->func.readInt32);
result = reader->func.readInt32(reader);
}
}
return result;
}
float Reader_ReadFloat(Reader *reader)
{
float result = 0;
if(Reader_Check(reader, 4))
{
if(!reader->useCustomFuncs)
{
float foreign;
Reader_TypeCheck(reader, WTCC_FLOAT);
memcpy(&foreign, reader->data + reader->pos, 4);
reader->pos += 4;
result = LittleEndianByteOrder_ToNativeFloat(foreign);
}
else
{
assert(reader->func.readFloat);
result = reader->func.readFloat(reader);
}
}
return result;
}
void Reader_Read(Reader *reader, void *buffer, size_t len)
{
if(!len) return;
if(Reader_Check(reader, len))
{
if(!reader->useCustomFuncs)
{
Reader_TypeCheck(reader, WTCC_BLOCK);
memcpy(buffer, reader->data + reader->pos, len);
reader->pos += len;
}
else
{
assert(reader->func.readData);
reader->func.readData(reader, buffer, len);
}
}
}
uint16_t Reader_ReadPackedUInt16(Reader *reader)
{
ushort pack = Reader_ReadByte(reader);
if(pack & 0x80)
{
pack &= ~0x80;
pack |= Reader_ReadByte(reader) << 7;
}
return pack;
}
uint32_t Reader_ReadPackedUInt32(Reader *reader)
{
byte pack = 0;
int pos = 0;
uint value = 0;
do {
if(!Reader_Check(reader, 1)) return 0;
pack = Reader_ReadByte(reader);
value |= ((pack & 0x7f) << pos);
pos += 7;
} while(pack & 0x80);
return value;
}