A utility for storing and retrieving byte data using a ring buffer. More...
Detailed Description
A utility for storing and retrieving byte data using a ring buffer.
The ringbuffer is useful for buffering data in the same thread context but it is not thread-safe. For a thread-safe ring buffer, see Thread safe ringbuffer in the System library.
Definition in file ringbuffer.h.
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Data Structures | |
| struct | ringbuffer_t |
| Ringbuffer. More... | |
Macros | |
| #define | RINGBUFFER_INIT(BUF) { (BUF), sizeof(BUF), 0, 0 } |
| Initialize a ringbuffer. More... | |
Functions | |
| static void | ringbuffer_init (ringbuffer_t *__restrict rb, char *buffer, unsigned bufsize) |
| Initialize a ringbuffer. More... | |
| int | ringbuffer_add_one (ringbuffer_t *__restrict rb, char c) |
| Add an element to the ringbuffer. More... | |
| unsigned | ringbuffer_add (ringbuffer_t *__restrict rb, const char *buf, unsigned n) |
| Add a number of elements to the ringbuffer. More... | |
| int | ringbuffer_get_one (ringbuffer_t *__restrict rb) |
| Peek and remove oldest element from the ringbuffer. More... | |
| unsigned | ringbuffer_get (ringbuffer_t *__restrict rb, char *buf, unsigned n) |
| Read and remove a number of elements from the ringbuffer. More... | |
| unsigned | ringbuffer_remove (ringbuffer_t *__restrict rb, unsigned n) |
| Remove a number of elements from the ringbuffer. More... | |
| static int | ringbuffer_empty (const ringbuffer_t *__restrict rb) |
| Test if the ringbuffer is empty. More... | |
| static int | ringbuffer_full (const ringbuffer_t *__restrict rb) |
| Test if the ringbuffer is full. More... | |
| static unsigned int | ringbuffer_get_free (const ringbuffer_t *__restrict rb) |
| Return available space in ringbuffer. More... | |
| int | ringbuffer_peek_one (const ringbuffer_t *__restrict rb) |
| Read, but don't remove, the oldest element in the buffer. More... | |
| unsigned | ringbuffer_peek (const ringbuffer_t *__restrict rb, char *buf, unsigned n) |
| Read, but don't remove, the a number of element of the buffer. More... | |
Macro Definition Documentation
◆ RINGBUFFER_INIT
| #define RINGBUFFER_INIT | ( | BUF | ) | { (BUF), sizeof(BUF), 0, 0 } |
Initialize a ringbuffer.
This macro is meant for static ringbuffers.
- Parameters
-
[in] BUF Buffer to use for the ringbuffer. The size is deduced through sizeof (BUF).
- Returns
- The static initializer.
Definition at line 50 of file ringbuffer.h.
Function Documentation
◆ ringbuffer_add()
| unsigned ringbuffer_add | ( | ringbuffer_t *__restrict | rb, |
| const char * | buf, | ||
| unsigned | n | ||
| ) |
Add a number of elements to the ringbuffer.
Only so many elements are added as fit in the ringbuffer. No elements get overwritten. If this is not the intended behavior, then use ringbuffer_add_one() in a loop instead.
- Parameters
-
[in,out] rb Ringbuffer to operate on. [in] buf Buffer to add elements from. [in] n Maximum number of elements to add.
- Returns
- Number of elements actually added. 0 if rb is full.
◆ ringbuffer_add_one()
| int ringbuffer_add_one | ( | ringbuffer_t *__restrict | rb, |
| char | c | ||
| ) |
Add an element to the ringbuffer.
If rb is full, then the oldest element gets overwritten. Test ringbuffer_full() first if overwriting is not intended.
- Parameters
-
[in,out] rb Ringbuffer to operate on. [in] c Element to add.
- Returns
- The element that was dropped, iff the buffer was full. -1 iff the buffer was not full.
◆ ringbuffer_empty()
|
inlinestatic |
Test if the ringbuffer is empty.
- Parameters
-
[in,out] rb Ringbuffer to operate on.
- Returns
- 0 iff not empty
Definition at line 120 of file ringbuffer.h.
◆ ringbuffer_full()
|
inlinestatic |
Test if the ringbuffer is full.
- Parameters
-
[in,out] rb Ringbuffer to operate on.
- Returns
- 0 iff not full
Definition at line 130 of file ringbuffer.h.
◆ ringbuffer_get()
| unsigned ringbuffer_get | ( | ringbuffer_t *__restrict | rb, |
| char * | buf, | ||
| unsigned | n | ||
| ) |
Read and remove a number of elements from the ringbuffer.
- Parameters
-
[in,out] rb Ringbuffer to operate on. [out] buf Buffer to write into. [in] n Read at most n elements.
- Returns
- Number of elements actually read.
◆ ringbuffer_get_free()
|
inlinestatic |
Return available space in ringbuffer.
- Parameters
-
[in,out] rb Ringbuffer to query.
- Returns
- number of available bytes
Definition at line 140 of file ringbuffer.h.
◆ ringbuffer_get_one()
| int ringbuffer_get_one | ( | ringbuffer_t *__restrict | rb | ) |
Peek and remove oldest element from the ringbuffer.
- Parameters
-
[in,out] rb Ringbuffer to operate on.
- Returns
- The oldest element that was added, or
-1if rb is empty.
◆ ringbuffer_init()
|
inlinestatic |
Initialize a ringbuffer.
- Parameters
-
[out] rb Datum to initialize. [in] buffer Buffer to use by rb. [in] bufsize sizeof (buffer)
Definition at line 58 of file ringbuffer.h.
◆ ringbuffer_peek()
| unsigned ringbuffer_peek | ( | const ringbuffer_t *__restrict | rb, |
| char * | buf, | ||
| unsigned | n | ||
| ) |
Read, but don't remove, the a number of element of the buffer.
- Parameters
-
[in] rb Ringbuffer to operate on. [out] buf Buffer to write into. [in] n Read at most n elements.
- Returns
- Same as ringbuffer_get()
◆ ringbuffer_peek_one()
| int ringbuffer_peek_one | ( | const ringbuffer_t *__restrict | rb | ) |
Read, but don't remove, the oldest element in the buffer.
- Parameters
-
[in] rb Ringbuffer to operate on.
- Returns
- Same as ringbuffer_get_one()
◆ ringbuffer_remove()
| unsigned ringbuffer_remove | ( | ringbuffer_t *__restrict | rb, |
| unsigned | n | ||
| ) |
Remove a number of elements from the ringbuffer.
- Parameters
-
[in,out] rb Ringbuffer to operate on. [in] n Read at most n elements.
- Returns
- Number of elements actually removed.
