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Diffstat (limited to 'include/haproxy/cbuf.h')
| -rw-r--r-- | include/haproxy/cbuf.h | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/include/haproxy/cbuf.h b/include/haproxy/cbuf.h new file mode 100644 index 0000000..b217a5c --- /dev/null +++ b/include/haproxy/cbuf.h @@ -0,0 +1,136 @@ +/* + * include/haprox/cbuf.h + * This file contains definitions and prototypes for circular buffers. + * Inspired from Linux circular buffers (include/linux/circ_buf.h). + * + * Copyright 2021 HAProxy Technologies, Frederic Lecaille <flecaille@haproxy.com> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation, version 2.1 + * exclusively. + * + * This library 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#ifndef _HAPROXY_CBUF_H +#define _HAPROXY_CBUF_H +#ifdef USE_QUIC +#ifndef USE_OPENSSL +#error "Must define USE_OPENSSL" +#endif +#endif + +#include <haproxy/atomic.h> +#include <haproxy/list.h> +#include <haproxy/cbuf-t.h> + +struct cbuf *cbuf_new(unsigned char *buf, size_t sz); +void cbuf_free(struct cbuf *cbuf); + +/* Amount of data between <rd> and <wr> */ +#define CBUF_DATA(wr, rd, size) (((wr) - (rd)) & ((size) - 1)) + +/* Return the writer position in <cbuf>. + * To be used only by the writer! + */ +static inline unsigned char *cb_wr(struct cbuf *cbuf) +{ + return cbuf->buf + cbuf->wr; +} + +/* Reset the reader index. + * To be used by a reader! + */ +static inline void cb_rd_reset(struct cbuf *cbuf) +{ + cbuf->rd = 0; +} + +/* Reset the writer index. + * To be used by a writer! + */ +static inline void cb_wr_reset(struct cbuf *cbuf) +{ + cbuf->wr = 0; +} + +/* Increase <cbuf> circular buffer data by <count>. + * To be used by a writer! + */ +static inline void cb_add(struct cbuf *cbuf, size_t count) +{ + cbuf->wr = (cbuf->wr + count) & (cbuf->sz - 1); +} + +/* Return the reader position in <cbuf>. + * To be used only by the reader! + */ +static inline unsigned char *cb_rd(struct cbuf *cbuf) +{ + return cbuf->buf + cbuf->rd; +} + +/* Skip <count> byte in <cbuf> circular buffer. + * To be used by a reader! + */ +static inline void cb_del(struct cbuf *cbuf, size_t count) +{ + cbuf->rd = (cbuf->rd + count) & (cbuf->sz - 1); +} + +/* Return the amount of data left in <cbuf>. + * To be used only by the writer! + */ +static inline size_t cb_data(struct cbuf *cbuf) +{ + size_t rd; + + rd = HA_ATOMIC_LOAD(&cbuf->rd); + return CBUF_DATA(cbuf->wr, rd, cbuf->sz); +} + +/* Return the amount of room left in <cbuf> minus 1 to distinguish + * the case where the buffer is full from the case where is is empty + * To be used only by the write! + */ +static inline size_t cb_room(struct cbuf *cbuf) +{ + size_t rd; + + rd = HA_ATOMIC_LOAD(&cbuf->rd); + return CBUF_DATA(rd, cbuf->wr + 1, cbuf->sz); +} + +/* Return the amount of contiguous data left in <cbuf>. + * To be used only by the reader! + */ +static inline size_t cb_contig_data(struct cbuf *cbuf) +{ + size_t end, n; + + end = cbuf->sz - cbuf->rd; + n = (HA_ATOMIC_LOAD(&cbuf->wr) + end) & (cbuf->sz - 1); + return n < end ? n : end; +} + +/* Return the amount of contiguous space left in <cbuf>. + * To be used only by the writer! + */ +static inline size_t cb_contig_space(struct cbuf *cbuf) +{ + size_t end, n; + + end = cbuf->sz - 1 - cbuf->wr; + n = (HA_ATOMIC_LOAD(&cbuf->rd) + end) & (cbuf->sz - 1); + return n <= end ? n : end + 1; +} + +#endif /* _HAPROXY_CBUF_H */ |