/* $Id$ */ /* * Copyright (c) 2010 Dimitri Sokolyuk * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include #include #include #include struct buf { double *buf; double *end; double *wr; double *rd; }; struct fifo { struct buf l; struct buf r; size_t sz; }; struct fifo * init_fifo(int n) { struct fifo *ff; ff = malloc(sizeof(struct fifo)); ff->l.buf = malloc(n * sizeof(double)); ff->l.end = ff->l.buf + n; ff->l.wr = ff->l.buf; ff->l.rd = ff->l.buf; ff->r.buf = malloc(n * sizeof(double)); ff->r.end = ff->r.buf + n; ff->r.wr = ff->r.buf; ff->r.rd = ff->r.buf; ff->sz = 0; return ff; } int wr_fifo(struct fifo *ff, double *l, double *r, int n) { int i; for (i = 0; i < n; i++) { *ff->l.wr++ = *l++; *ff->r.wr++ = *r++; if (ff->l.wr >= ff->l.end) { ff->l.wr = ff->l.buf; ff->r.wr = ff->r.buf; } } ff->sz += n; return ff->sz; } int rd_fifo(struct fifo *ff, double *l, double *r, int n, double *w) { int i; double *lnext = ff->l.rd; double *rnext = ff->r.rd; for (i = 0; i < n; i++) { if (i == n / 4) { lnext = ff->l.rd; rnext = ff->r.rd; } *l++ = *ff->l.rd++ * w[i]; *r++ = *ff->r.rd++ * w[i]; if (ff->l.rd >= ff->l.end) { ff->l.rd = ff->l.buf; ff->r.rd = ff->r.buf; } } ff->l.rd = lnext; ff->r.rd = rnext; ff->sz -= n / 4; return ff->sz; }