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author | Mattias Andrée <maandree@kth.se> | 2019-10-22 15:04:45 +0200 |
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committer | Mattias Andrée <maandree@kth.se> | 2019-10-22 15:04:45 +0200 |
commit | b13efce73e506b0feb4bb7c275c273a54ae6e716 (patch) | |
tree | 79f93e69b01d236e96037aa60332d214696e048b /types-ring.h | |
parent | Fix NULL-pointer bug in get_pathname when running with -mdrm (diff) | |
download | coopgammad-b13efce73e506b0feb4bb7c275c273a54ae6e716.tar.gz coopgammad-b13efce73e506b0feb4bb7c275c273a54ae6e716.tar.bz2 coopgammad-b13efce73e506b0feb4bb7c275c273a54ae6e716.tar.xz |
Change license and style, reorganise file, make makefile portable, and fix bugs1.3
Signed-off-by: Mattias Andrée <maandree@kth.se>
Diffstat (limited to 'types-ring.h')
-rw-r--r-- | types-ring.h | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/types-ring.h b/types-ring.h new file mode 100644 index 0000000..c8b5f77 --- /dev/null +++ b/types-ring.h @@ -0,0 +1,131 @@ +/* See LICENSE file for copyright and license details. */ +#ifndef TYPES_RING_H +#define TYPES_RING_H + +#include <stdlib.h> + +#ifndef GCC_ONLY +# if defined(__GNUC__) && !defined(__clang__) +# define GCC_ONLY(...) __VA_ARGS__ +# else +# define GCC_ONLY(...) /* nothing */ +# endif +#endif + +/** + * Ring buffer + */ +struct ring { + /** + * Buffer for the data + */ + char *restrict buffer; + + /** + * The first set byte in `.buffer` + */ + size_t start; + + /** + * The last set byte in `.buffer`, plus 1 + */ + size_t end; + + /** + * The size of `.buffer` + */ + size_t size; +}; + +/** + * Initialise a ring buffer + * + * @param this The ring buffer + */ +GCC_ONLY(__attribute__((__nonnull__))) +void ring_initialise(struct ring *restrict this); + +/** + * Marshal a ring buffer + * + * @param this The ring buffer + * @param buf Output buffer for the marshalled data, + * `NULL` to only measure how large buffer + * is needed + * @return The number of marshalled bytes + */ +GCC_ONLY(__attribute__((__nonnull__(1)))) +size_t ring_marshal(const struct ring *restrict this, void *restrict buf); + +/** + * Unmarshal a ring buffer + * + * @param this Output parameter for the ring buffer + * @param buf Buffer with the marshalled data + * @return The number of unmarshalled bytes, 0 on error + */ +GCC_ONLY(__attribute__((__nonnull__))) +size_t ring_unmarshal(struct ring *restrict this, const void *restrict buf); + +/** + * Append data to a ring buffer + * + * @param this The ring buffer + * @param data The new data + * @param n The number of bytes in `data` + * @return Zero on success, -1 on error + */ +GCC_ONLY(__attribute__((__nonnull__(1)))) +int ring_push(struct ring *restrict this, void *restrict data, size_t n); + +/** + * Get queued data from a ring buffer + * + * It can take up to two calls (with `ring_pop` between) + * to get all queued data + * + * @param this The ring buffer + * @param n Output parameter for the length + * of the returned segment + * @return The beginning of the queued data, + * `NULL` if there is nothing more + */ +GCC_ONLY(__attribute__((__nonnull__))) +void *ring_peek(struct ring *restrict this, size_t *restrict n); + +/** + * Dequeue data from a ring bubber + * + * @param this The ring buffer + * @param n The number of bytes to dequeue + */ +GCC_ONLY(__attribute__((__nonnull__))) +void ring_pop(struct ring *restrict this, size_t n); + +/** + * Release resource allocated to a ring buffer + * + * @param this The ring buffer + */ +GCC_ONLY(__attribute__((__nonnull__))) +static inline void +ring_destroy(struct ring *restrict this) +{ + free(this->buffer); +} + +/** + * Check whether there is more data waiting + * in a ring buffer + * + * @param this The ring buffer + * @return 1 if there is more data, 0 otherwise + */ +GCC_ONLY(__attribute__((__nonnull__))) +static inline int +ring_have_more(struct ring *restrict this) +{ + return !!this->buffer; +} + +#endif |