ldns  1.7.0
buffer.h
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1 /*
2  * buffer.h -- generic memory buffer.
3  *
4  * Copyright (c) 2005-2008, NLnet Labs. All rights reserved.
5  *
6  * See LICENSE for the license.
7  *
8  *
9  * The buffer module implements a generic buffer. The API is based on
10  * the java.nio.Buffer interface.
11  */
12 
13 #ifndef LDNS_BUFFER_H
14 #define LDNS_BUFFER_H
15 
16 #include <assert.h>
17 #include <stdarg.h>
18 #include <string.h>
19 
20 #include <ldns/error.h>
21 #include <ldns/common.h>
22 
23 #include "ldns/util.h"
24 
25 #ifdef __cplusplus
26 extern "C" {
27 #endif
28 
33 #define LDNS_MIN_BUFLEN 512
34 
51 {
53  size_t _position;
54 
56  size_t _limit;
57 
59  size_t _capacity;
60 
62  uint8_t *_data;
63 
65  unsigned _fixed : 1;
66 
71 };
73 
74 
75 #ifdef NDEBUG
76 INLINE void
77 ldns_buffer_invariant(const ldns_buffer *ATTR_UNUSED(buffer))
78 {
79 }
80 #else
81 INLINE void
82 ldns_buffer_invariant(const ldns_buffer *buffer)
83 {
84  assert(buffer != NULL);
85  assert(buffer->_position <= buffer->_limit);
86  assert(buffer->_limit <= buffer->_capacity);
87  assert(buffer->_data != NULL);
88 }
89 #endif
90 
97 ldns_buffer *ldns_buffer_new(size_t capacity);
98 
108 void ldns_buffer_new_frm_data(ldns_buffer *buffer, const void *data, size_t size);
109 
115 INLINE void ldns_buffer_clear(ldns_buffer *buffer)
116 {
117  ldns_buffer_invariant(buffer);
118 
119  /* reset status here? */
120 
121  buffer->_position = 0;
122  buffer->_limit = buffer->_capacity;
123 }
124 
133 INLINE void ldns_buffer_flip(ldns_buffer *buffer)
134 {
135  ldns_buffer_invariant(buffer);
136 
137  buffer->_limit = buffer->_position;
138  buffer->_position = 0;
139 }
140 
146 INLINE void ldns_buffer_rewind(ldns_buffer *buffer)
147 {
148  ldns_buffer_invariant(buffer);
149 
150  buffer->_position = 0;
151 }
152 
158 INLINE size_t
159 ldns_buffer_position(const ldns_buffer *buffer)
160 {
161  return buffer->_position;
162 }
163 
170 INLINE void
171 ldns_buffer_set_position(ldns_buffer *buffer, size_t mark)
172 {
173  assert(mark <= buffer->_limit);
174  buffer->_position = mark;
175 }
176 
184 INLINE void
185 ldns_buffer_skip(ldns_buffer *buffer, ssize_t count)
186 {
187  assert(buffer->_position + count <= buffer->_limit);
188  buffer->_position += count;
189 }
190 
196 INLINE size_t
197 ldns_buffer_limit(const ldns_buffer *buffer)
198 {
199  return buffer->_limit;
200 }
201 
208 INLINE void
209 ldns_buffer_set_limit(ldns_buffer *buffer, size_t limit)
210 {
211  assert(limit <= buffer->_capacity);
212  buffer->_limit = limit;
213  if (buffer->_position > buffer->_limit)
214  buffer->_position = buffer->_limit;
215 }
216 
222 INLINE size_t
223 ldns_buffer_capacity(const ldns_buffer *buffer)
224 {
225  return buffer->_capacity;
226 }
227 
236 bool ldns_buffer_set_capacity(ldns_buffer *buffer, size_t capacity);
237 
248 bool ldns_buffer_reserve(ldns_buffer *buffer, size_t amount);
249 
256 INLINE uint8_t *
257 ldns_buffer_at(const ldns_buffer *buffer, size_t at)
258 {
259  assert(at <= buffer->_limit);
260  return buffer->_data + at;
261 }
262 
269 INLINE uint8_t *
270 ldns_buffer_begin(const ldns_buffer *buffer)
271 {
272  return ldns_buffer_at(buffer, 0);
273 }
274 
281 INLINE uint8_t *
282 ldns_buffer_end(const ldns_buffer *buffer)
283 {
284  return ldns_buffer_at(buffer, buffer->_limit);
285 }
286 
292 INLINE uint8_t *
293 ldns_buffer_current(const ldns_buffer *buffer)
294 {
295  return ldns_buffer_at(buffer, buffer->_position);
296 }
297 
305 INLINE size_t
306 ldns_buffer_remaining_at(const ldns_buffer *buffer, size_t at)
307 {
308  ldns_buffer_invariant(buffer);
309  assert(at <= buffer->_limit);
310  return buffer->_limit - at;
311 }
312 
319 INLINE size_t
320 ldns_buffer_remaining(const ldns_buffer *buffer)
321 {
322  return ldns_buffer_remaining_at(buffer, buffer->_position);
323 }
324 
334 INLINE int
335 ldns_buffer_available_at(const ldns_buffer *buffer, size_t at, size_t count)
336 {
337  return count <= ldns_buffer_remaining_at(buffer, at);
338 }
339 
346 INLINE int
347 ldns_buffer_available(const ldns_buffer *buffer, size_t count)
348 {
349  return ldns_buffer_available_at(buffer, buffer->_position, count);
350 }
351 
359 INLINE void
360 ldns_buffer_write_at(ldns_buffer *buffer, size_t at, const void *data, size_t count)
361 {
362  assert(ldns_buffer_available_at(buffer, at, count));
363  memcpy(buffer->_data + at, data, count);
364 }
365 
372 INLINE void
373 ldns_buffer_write(ldns_buffer *buffer, const void *data, size_t count)
374 {
375  ldns_buffer_write_at(buffer, buffer->_position, data, count);
376  buffer->_position += count;
377 }
378 
385 INLINE void
386 ldns_buffer_write_string_at(ldns_buffer *buffer, size_t at, const char *str)
387 {
388  ldns_buffer_write_at(buffer, at, str, strlen(str));
389 }
390 
396 INLINE void
397 ldns_buffer_write_string(ldns_buffer *buffer, const char *str)
398 {
399  ldns_buffer_write(buffer, str, strlen(str));
400 }
401 
408 INLINE void
409 ldns_buffer_write_u8_at(ldns_buffer *buffer, size_t at, uint8_t data)
410 {
411  assert(ldns_buffer_available_at(buffer, at, sizeof(data)));
412  buffer->_data[at] = data;
413 }
414 
420 INLINE void
421 ldns_buffer_write_u8(ldns_buffer *buffer, uint8_t data)
422 {
423  ldns_buffer_write_u8_at(buffer, buffer->_position, data);
424  buffer->_position += sizeof(data);
425 }
426 
433 INLINE void
434 ldns_buffer_write_u16_at(ldns_buffer *buffer, size_t at, uint16_t data)
435 {
436  assert(ldns_buffer_available_at(buffer, at, sizeof(data)));
437  ldns_write_uint16(buffer->_data + at, data);
438 }
439 
445 INLINE void
446 ldns_buffer_write_u16(ldns_buffer *buffer, uint16_t data)
447 {
448  ldns_buffer_write_u16_at(buffer, buffer->_position, data);
449  buffer->_position += sizeof(data);
450 }
451 
458 INLINE void
459 ldns_buffer_write_u32_at(ldns_buffer *buffer, size_t at, uint32_t data)
460 {
461  assert(ldns_buffer_available_at(buffer, at, sizeof(data)));
462  ldns_write_uint32(buffer->_data + at, data);
463 }
464 
470 INLINE void
471 ldns_buffer_write_u32(ldns_buffer *buffer, uint32_t data)
472 {
473  ldns_buffer_write_u32_at(buffer, buffer->_position, data);
474  buffer->_position += sizeof(data);
475 }
476 
484 INLINE void
485 ldns_buffer_read_at(const ldns_buffer *buffer, size_t at, void *data, size_t count)
486 {
487  assert(ldns_buffer_available_at(buffer, at, count));
488  memcpy(data, buffer->_data + at, count);
489 }
490 
497 INLINE void
498 ldns_buffer_read(ldns_buffer *buffer, void *data, size_t count)
499 {
500  ldns_buffer_read_at(buffer, buffer->_position, data, count);
501  buffer->_position += count;
502 }
503 
510 INLINE uint8_t
511 ldns_buffer_read_u8_at(const ldns_buffer *buffer, size_t at)
512 {
513  assert(ldns_buffer_available_at(buffer, at, sizeof(uint8_t)));
514  return buffer->_data[at];
515 }
516 
522 INLINE uint8_t
523 ldns_buffer_read_u8(ldns_buffer *buffer)
524 {
525  uint8_t result = ldns_buffer_read_u8_at(buffer, buffer->_position);
526  buffer->_position += sizeof(uint8_t);
527  return result;
528 }
529 
536 INLINE uint16_t
537 ldns_buffer_read_u16_at(ldns_buffer *buffer, size_t at)
538 {
539  assert(ldns_buffer_available_at(buffer, at, sizeof(uint16_t)));
540  return ldns_read_uint16(buffer->_data + at);
541 }
542 
548 INLINE uint16_t
549 ldns_buffer_read_u16(ldns_buffer *buffer)
550 {
551  uint16_t result = ldns_buffer_read_u16_at(buffer, buffer->_position);
552  buffer->_position += sizeof(uint16_t);
553  return result;
554 }
555 
562 INLINE uint32_t
563 ldns_buffer_read_u32_at(ldns_buffer *buffer, size_t at)
564 {
565  assert(ldns_buffer_available_at(buffer, at, sizeof(uint32_t)));
566  return ldns_read_uint32(buffer->_data + at);
567 }
568 
574 INLINE uint32_t
575 ldns_buffer_read_u32(ldns_buffer *buffer)
576 {
577  uint32_t result = ldns_buffer_read_u32_at(buffer, buffer->_position);
578  buffer->_position += sizeof(uint32_t);
579  return result;
580 }
581 
588 ldns_buffer_status(const ldns_buffer *buffer)
589 {
590  return buffer->_status;
591 }
592 
598 INLINE bool
599 ldns_buffer_status_ok(const ldns_buffer *buffer)
600 {
601  if (buffer) {
602  return ldns_buffer_status(buffer) == LDNS_STATUS_OK;
603  } else {
604  return false;
605  }
606 }
607 
614 int ldns_buffer_printf(ldns_buffer *buffer, const char *format, ...);
615 /* ATTR_FORMAT(printf, 2, 3);*/
616 
622 void ldns_buffer_free(ldns_buffer *buffer);
623 
630 void *ldns_buffer_export(ldns_buffer *buffer);
631 
639 void ldns_buffer_copy(ldns_buffer* result, const ldns_buffer* from);
640 
641 #ifdef __cplusplus
642 }
643 #endif
644 
645 #endif /* LDNS_BUFFER_H */
void ldns_buffer_copy(ldns_buffer *result, const ldns_buffer *from)
Copy contents of the from buffer to the result buffer and then flips the result buffer.
Definition: buffer.c:168
implementation of buffers to ease operations
Definition: buffer.h:50
ldns_status _status
The current state of the buffer.
Definition: buffer.h:70
void ldns_buffer_free(ldns_buffer *buffer)
frees the buffer.
Definition: buffer.c:137
size_t _limit
The read/write limit.
Definition: buffer.h:56
size_t _capacity
The amount of data the buffer can contain.
Definition: buffer.h:59
void ldns_buffer_new_frm_data(ldns_buffer *buffer, const void *data, size_t size)
creates a buffer with the specified data.
Definition: buffer.c:41
void * ldns_buffer_export(ldns_buffer *buffer)
Makes the buffer fixed and returns a pointer to the data.
Definition: buffer.c:150
#define INLINE
splint static inline workaround
Definition: util.h:42
Defines error numbers and functions to translate those to a readable string.
bool ldns_buffer_set_capacity(ldns_buffer *buffer, size_t capacity)
changes the buffer&#39;s capacity.
Definition: buffer.c:60
#define ATTR_UNUSED(x)
Definition: common.h:69
size_t _position
The current position used for reading/writing.
Definition: buffer.h:53
bool ldns_buffer_reserve(ldns_buffer *buffer, size_t amount)
ensures BUFFER can contain at least AMOUNT more bytes.
Definition: buffer.c:79
ldns_buffer * ldns_buffer_new(size_t capacity)
creates a new buffer with the specified capacity.
Definition: buffer.c:16
enum ldns_enum_status ldns_status
Definition: error.h:134
Common definitions for LDNS.
unsigned _fixed
If the buffer is fixed it cannot be resized.
Definition: buffer.h:65
uint8_t * _data
The data contained in the buffer.
Definition: buffer.h:62
int ldns_buffer_printf(ldns_buffer *buffer, const char *format,...)
prints to the buffer, increasing the capacity if required using buffer_reserve(). ...
Definition: buffer.c:99