X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=ringbuffer.c;h=b27fd8e8a25c4ccd52756f2e9c0f30e1c3b4162b;hp=4644ee6e8ed3d002dc5b562d6fd6b9c24c7e1fe3;hb=0dd69d3988a677aeb8d0d3aea8364c664ac35fb9;hpb=4b4c68de8d7390f966e46d9402d5499d2e8ee227 diff --git a/ringbuffer.c b/ringbuffer.c index 4644ee6e..b27fd8e8 100644 --- a/ringbuffer.c +++ b/ringbuffer.c @@ -1,63 +1,36 @@ /* - * Copyright (C) 2006 Andre Noll + * Copyright (C) 2006-2009 Andre Noll * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program 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 General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA. + * Licensed under the GPL v2. For licencing details see COPYING. */ -/** \file ringbuffer.c simple ringbuffer implementation */ +/** \file ringbuffer.c Simple ringbuffer implementation */ #include "para.h" #include "ringbuffer.h" #include "string.h" /** - * holds all information about one ring buffer + * Holds all information about one ring buffer * * It is intentionally not exported via ringbuffer.h. Think abstract. */ struct ringbuffer { -/** - * - * - * the size of this ring buffer -*/ -unsigned size; -/** - * - * - * the actual entries of the ringbuffer -*/ -void **entries; -/** - * - * - * the next entry will be added at this position - */ -int head; -/** - * - * how many entries the ring buffer contains -*/ -unsigned filled; + /** The size of this ring buffer. */ + unsigned size; + /** The actual entries of the ringbuffer. */ + void **entries; + /** The next entry will be added at this position. */ + int head; + /** How many entries the ring buffer contains. */ + unsigned filled; }; /** - * initialize a new ringbuffer + * Initialize a new ringbuffer. * - * @param size the number of entries the ringbuffer holds + * \param size The number of entries the ringbuffer holds. * * This function initializes a circular ring buffer which can hold up to \a * size entries of arbitrary type. If performance is an issue, \a size should @@ -65,33 +38,32 @@ unsigned filled; * many ringbuffers may be initialized via this function. Each ringbuffer is * identified by a 'cookie'. * - * Return value: A 'cookie' which identifies the ringbuffer just created and + * \return A 'cookie' which identifies the ringbuffer just created and * which must be passed to ringbuffer_add() and ringbuffer_get(). */ -void *ringbuffer_new(unsigned size) +struct ringbuffer *ringbuffer_new(unsigned size) { struct ringbuffer *rb = para_calloc(sizeof(struct ringbuffer)); rb->entries = para_calloc(size * sizeof(void *)); rb->size = size; return rb; -}; +} /** - * add one entry to a ringbuffer + * Add one entry to a ringbuffer. * - * @param cookie the ringbuffer identifier - * @param data the data to be inserted + * \param rb The ringbuffer identifier. + * \param data The data to be inserted. * - * insert \a data into the ringbuffer associated with \a cookie. As soon as + * Insert \a data into the ringbuffer associated with \a cookie. As soon as * the ringbuffer fills up, its oldest entry is disregarded and replaced by \a * data. * * \return The old \a data pointer which is going to be disregarded, or * NULL if the ringbuffer is not yet full. */ -void *ringbuffer_add(void *cookie, void *data) +void *ringbuffer_add(struct ringbuffer *rb, void *data) { - struct ringbuffer *rb = cookie; void *ret = rb->entries[rb->head]; rb->entries[rb->head] = data; rb->head = (rb->head + 1) % rb->size; @@ -101,33 +73,31 @@ void *ringbuffer_add(void *cookie, void *data) } /** - * get one entry from a ringbuffer + * Get one entry from a ringbuffer. * - * @param cookie the ringbuffer identifier - * @param num the number of the entry + * \param rb The ringbuffer identifier. + * \param num The number of the entry. * * \return A pointer to data previously added, or NULL if entry number * \a num is not available. \a num counts backwards from zero, i.e. * ringbuffer_get_entry(0) gets the entry which was added most recently. */ -void *ringbuffer_get(void *cookie, int num) +void *ringbuffer_get(struct ringbuffer *rb, int num) { - struct ringbuffer *rb = cookie; int pos = (rb->head + rb->size - 1 - num) % rb->size; // fprintf(stderr, "pos = %d\n", pos); return rb->entries[pos]; } /** - * get the number of entries in the ring buffer + * Get the number of entries in the ring buffer. * - * @param cookie the ringbuffer identifier + * \param rb The ringbuffer identifier * * This function always succeeds and never returns a number greater than the * size of the ring buffer. */ -unsigned ringbuffer_filled(void *cookie) +unsigned ringbuffer_filled(struct ringbuffer *rb) { - struct ringbuffer *rb = cookie; return rb->filled; }