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Diffstat (limited to 'lib/includes/hicn/util/ring.h')
| -rw-r--r-- | lib/includes/hicn/util/ring.h | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/lib/includes/hicn/util/ring.h b/lib/includes/hicn/util/ring.h new file mode 100644 index 000000000..9510672b3 --- /dev/null +++ b/lib/includes/hicn/util/ring.h @@ -0,0 +1,227 @@ +/* + * Copyright (c) 2021 Cisco and/or its affiliates. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +/** + * \file ring.h + * \brief Fixed-size pool allocator. + */ + +#ifndef UTIL_RING_H +#define UTIL_RING_H + +#include <assert.h> +#include <stdint.h> +#include <string.h> +#include <sys/param.h> // MIN +#include <sys/types.h> + +#include <stdio.h> // XXX debug + +#include "../common.h" + +/******************************************************************************/ +/* Ring header */ + +typedef struct +{ + size_t roff; + size_t woff; + size_t size; + size_t max_size; +} ring_hdr_t; + +/* Make sure elements following the header are aligned */ +#define RING_HDRLEN SIZEOF_ALIGNED (ring_hdr_t) + +/* This header actually prepends the actual content of the vector */ +#define ring_hdr(ring) ((ring_hdr_t *) ((uint8_t *) ring - RING_HDRLEN)) + +/******************************************************************************/ +/* Helpers */ + +/** Local variable naming macro. */ +#define _ring_var(v) _ring_##v + +/** + * @brief Allocate and initialize a ring data structure (helper function). + * + * @param[in,out] ring_ptr Ring buffer to allocate and initialize. + * @param[in] elt_size Size of a ring element. + * @param[in] max_size Maximum vector size (O = unlimited). + */ +void _ring_init (void **ring_ptr, size_t elt_size, size_t max_size); + +/** + * @brief Free a ring data structure. + * + * @param ring_ptr[in] Pointer to the ring data structure to free. + */ +void _ring_free (void **ring_ptr); + +static inline int +_ring_add (void **ring_ptr, size_t elt_size, void *eltp) +{ + assert (*ring_ptr); + ring_hdr_t *rh = ring_hdr (*ring_ptr); + + /* We always write ! */ + memcpy ((uint8_t *) *ring_ptr + rh->woff * elt_size, eltp, elt_size); + rh->woff++; + if (rh->woff == rh->max_size) + rh->woff = 0; + if (rh->size < rh->max_size) + { + rh->size++; + } + else + { + /* One packet was dropped */ + rh->roff++; + if (rh->roff == rh->max_size) + rh->roff = 0; + } + return 0; +} + +static inline unsigned +_ring_get_fullness (void **ring_ptr) +{ + assert (*ring_ptr); + ring_hdr_t *rh = ring_hdr (*ring_ptr); + return (unsigned int) (rh->size * 100 / rh->max_size); +} + +static inline unsigned +_ring_is_full (void **ring_ptr) +{ + assert (*ring_ptr); + ring_hdr_t *rh = ring_hdr (*ring_ptr); + return rh->size == rh->max_size; +} + +static inline size_t +_ring_get_size (void **ring_ptr) +{ + assert (*ring_ptr); + ring_hdr_t *rh = ring_hdr (*ring_ptr); + return rh->size; +} + +static inline int +_ring_advance (void **ring_ptr, unsigned n) +{ + assert (*ring_ptr); + ring_hdr_t *rh = ring_hdr (*ring_ptr); + assert (n <= rh->size); + + rh->roff += n; + rh->size -= n; + while (rh->roff >= rh->max_size) + rh->roff -= rh->max_size; + return 0; +} + +static inline int +_ring_get (void **ring_ptr, size_t elt_size, unsigned i, void *eltp) +{ + assert (*ring_ptr); + ring_hdr_t *rh = ring_hdr (*ring_ptr); + assert (i <= rh->size); + size_t pos = rh->roff + i; + if (pos >= rh->max_size) + pos -= rh->max_size; + memcpy (eltp, (uint8_t *) *ring_ptr + pos * elt_size, elt_size); + return 0; +} + +/******************************************************************************/ +/* Public API */ + +/** + * @brief Allocate and initialize a ring data structure. + * + * @param[in,out] ring Ring to allocate and initialize. + * @param[in] max_size Maximum ring size (nonzero). + * + * NOTE: + * - Allocated memory is set to 0 (used by bitmap) + */ + +#define ring_init(RING, MAX_SIZE) \ + _ring_init ((void **) &(RING), sizeof ((RING)[0]), (MAX_SIZE)) + +#define ring_free(RING) _ring_free ((void **) &(RING)) + +#define ring_get_fullness(RING) _ring_get_fullness ((void **) &(RING)) + +#define ring_is_full(RING) _ring_is_full ((void **) &(RING)) + +#define ring_get_size(RING) _ring_get_size ((void **) &(RING)) + +#define ring_add(RING, ELT) \ + _ring_add ((void **) &(RING), sizeof (RING[0]), ELT) + +#define ring_add_value(RING, VALUE) \ + do \ + { \ + typeof (VALUE) _ring_var (v) = VALUE; \ + _ring_add ((void **) &(RING), sizeof (RING[0]), &_ring_var (v)); \ + } \ + while (0) + +#define ring_advance(RING, N) _ring_advance ((void **) &(RING), (N)) + +#define ring_get(RING, I, ELTP) \ + _ring_get ((void **) &RING, sizeof (RING[0]), (I), (ELTP)) + +/** + * @brief Helper function used by ring_foreach(). + */ +#define ring_enumerate_n(RING, I, ELTP, COUNT, BODY) \ + ({ \ + for ((I) = 0; (I) < MIN (ring_get_size (RING), (COUNT)); (I)++) \ + { \ + ring_get ((RING), (I), (ELTP)); \ + { \ + BODY; \ + } \ + } \ + }) + +#define ring_enumerate(ring, i, eltp, BODY) \ + ring_enumerate_n ((ring), (i), (eltp), 1, (BODY)) + +/** + * @brief Iterate over elements in a ring. + * + * @param[in] pool The ring data structure to iterate over + * @param[in, out] eltp A pointer to the element that will be used for + * iteration + * @param[in] BODY Block to execute during iteration + * + * @note Iteration will execute BODY with eltp corresponding successively to + * all elements found in the ring. It is implemented using the more generic + * enumeration function. + */ +#define ring_foreach_n(ring, eltp, count, BODY) \ + ({ \ + unsigned _ring_var (i); \ + ring_enumerate_n ((ring), _ring_var (i), (eltp), (count), BODY); \ + }) + +#define ring_foreach(ring, eltp, BODY) \ + ring_foreach_n ((ring), (eltp), 1, (BODY)) + +#endif /* UTIL_RING_H */ |