https://github.com/smfsw/cqueue
Queue handling library (written in plain c)
https://github.com/smfsw/cqueue
fifo lifo queue
Last synced: 12 months ago
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Queue handling library (written in plain c)
- Host: GitHub
- URL: https://github.com/smfsw/cqueue
- Owner: SMFSW
- License: bsd-3-clause
- Created: 2017-08-13T14:34:31.000Z (almost 9 years ago)
- Default Branch: master
- Last Pushed: 2025-05-06T21:58:10.000Z (about 1 year ago)
- Last Synced: 2025-05-06T22:36:06.666Z (about 1 year ago)
- Topics: fifo, lifo, queue
- Language: C
- Size: 3.92 MB
- Stars: 66
- Watchers: 6
- Forks: 16
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# cQueue [](https://travis-ci.com/SMFSW/cQueue)
Queue handling library (written in plain c)
This library is designed for a c implementation on embedded devices, yet may be compiled without change with gcc for other purposes/targets.
Designed as a library to be compatible with Arduino LibManager specifications (yet rather use Queue instead - https://github.com/SMFSW/Queue).
## Usage
- Initialize a Queue using `q_init(Queue_t * pQ, size_t size_rec, uint16_t nb_recs, QueueType type, bool overwrite)`:
- `pQ` - pointer to the queue struct
- `size_rec` - size of a record in the queue
- `nb_recs` - number of records in the queue
- `type` - queue implementation type: `FIFO`, `LIFO`
- `overwrite` - overwrite previous records when queue is full if set to `true`
- OR a statically allocated Queue using `q_init_static(Queue_t * pQ, size_t size_rec, uint16_t nb_recs, QueueType type, bool overwrite, void * pQDat, size_t lenQDat)`:
- `pQ` - pointer to the queue struct
- `size_rec` - size of a record in the queue
- `nb_recs` - number of records in the queue
- `type` - queue implementation type: `FIFO`, `LIFO`
- `overwrite` - overwrite previous records when queue is full if set to `true`
- `pQDat` - pointer to static data queue
- `lenQDat` - length of static data queue (in bytes)
- Push stuff to the queue using `q_push(Queue_t * pQ, void * rec)`
- returns `true` if successfully pushed into queue
- returns `false` is queue is full
- Pop stuff from the queue using `q_pop(Queue_t * pQ, void * rec)` or `q_pull(Queue_t * pQ, void * rec)`
- returns `true` if successfully popped from queue
- returns `false` if queue is empty
- Peek stuff from the queue using `q_peek(Queue_t * pQ, void * rec)`
- returns `true` if successfully peeked from queue
- returns `false` if queue is empty
- Drop stuff from the queue using `q_drop(Queue_t * pQ)`
- returns `true` if successfully dropped from queue
- returns `false` if queue is empty
- Peek stuff at index from the queue using `q_peekIdx(Queue_t * pQ, void * rec, uint16_t idx)`
- returns `true` if successfully peeked from queue
- returns `false` if index is out of range
- warning: no associated drop function, not to use with `q_drop`
- Peek latest stored from the queue using `q_peekPrevious(Queue_t * pQ, void * rec)`
- returns `true` if successfully peeked from queue
- returns `false` if queue is empty
- warning: no associated drop function, not to use with `q_drop`
- note: only useful with FIFO implementation, use `q_peek` instead with a LIFO
- Other methods:
- `q_isInitialized(Queue_t * pQ)`: `true` if initialized properly, `false` otherwise
- `q_isEmpty(Queue_t * pQ)`: `true` if empty, `false` otherwise
- `q_isFull(Queue_t * pQ)`: `true` if full, `false` otherwise
- `q_sizeof(Queue_t * pQ)`: queue size in bytes (returns 0 in case queue allocation failed)
- `q_getCount(Queue_t * pQ)` or `q_nbRecs(Queue_t * pQ)`: number of records stored in the queue
- `q_getRemainingCount(Queue_t * pQ)`: number of records left in the queue
- `q_clean(Queue_t * pQ)` or `q_flush(Queue_t * pQ)`: remove all items in the queue
## Notes
- Interrupt safe automation is not implemented in the library. You have to manually disable/enable interrupts where required.
No implementation will be made as it would be an issue when using `peek`/`drop` methods with LIFO implementation:
if an item is put to the queue through interrupt between `peek` and `drop` calls, the `drop` call would drop the wrong (newer) item.
In this particular case, dropping decision must be made before re-enabling interrupts.
## Examples included
- [SimpleQueue.ino](examples/SimpleQueue/SimpleQueue.ino): Simple queue example (both LIFO FIFO implementations can be tested)
- [SimpleQueueStatic.ino](examples/SimpleQueueStatic/SimpleQueueStatic.ino): Simple queue example using static queue data array (both LIFO FIFO implementations can be tested)
- [PointersQueue.ino](examples/PointersQueue/PointersQueue.ino): Queue of function pointers performing queued actions
- [QueueDuplicates.ino](examples/QueueDuplicates/QueueDuplicates.ino): Simple test to test queue duplicates before pushing to queue
- [QueueIdxPeeking.ino](examples/QueueIdxPeeking/QueueIdxPeeking.ino): Simple test to test queue index picking
- [RolloverTest.ino](examples/RolloverTest/RolloverTest.ino): Simple test to test queue rollover (for lib testing purposes mainly)
- [LibTst.ino](examples/LibTst/LibTst.ino): flexible test (for lib testing purposes mainly)
## Documentation
Doxygen doc can be generated using "Doxyfile".
See [generated documentation](https://smfsw.github.io/cQueue/)
## Release Notes
See [release notes](ReleaseNotes.md)
## See also
[Queue](https://github.com/SMFSW/Queue) - Cpp implementation of this library