Mercurial > hg > audiostuff
view spandsp-0.0.3/spandsp-0.0.3/src/queue.c @ 5:f762bf195c4b
import spandsp-0.0.3
author | Peter Meerwald <pmeerw@cosy.sbg.ac.at> |
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date | Fri, 25 Jun 2010 16:00:21 +0200 |
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/* * SpanDSP - a series of DSP components for telephony * * queue.c - simple in process message queuing * * Written by Steve Underwood <steveu@coppice.org> * * Copyright (C) 2004 Steve Underwood * * All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2, as * published by the Free Software Foundation. * * 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., 675 Mass Ave, Cambridge, MA 02139, USA. * * $Id: queue.c,v 1.10 2006/11/19 14:07:25 steveu Exp $ */ /*! \file */ #ifdef HAVE_CONFIG_H #include <config.h> #endif #include <stdio.h> #include <string.h> #include <time.h> #include <ctype.h> #include <stdlib.h> #include <inttypes.h> #include <sys/types.h> #include <tiffio.h> #include "spandsp/queue.h" int queue_empty(queue_t *p) { return (p->iptr == p->optr); } /*- End of function --------------------------------------------------------*/ int queue_free_space(queue_t *p) { if (p->iptr < p->optr) return ((p->optr - p->iptr) - 1); /*endif*/ return (p->len - (p->iptr - p->optr)); } /*- End of function --------------------------------------------------------*/ int queue_contents(queue_t *p) { if (p->iptr < p->optr) return (p->len - (p->optr - p->iptr) + 1); /*endif*/ return (p->iptr - p->optr); } /*- End of function --------------------------------------------------------*/ void queue_flush(queue_t *p) { p->iptr = p->optr = 0; } /*- End of function --------------------------------------------------------*/ int queue_view(queue_t *p, uint8_t *buf, int len) { int real_len; int to_end; real_len = queue_contents(p); if (real_len < len) { if (p->flags & QUEUE_READ_ATOMIC) return -1; /*endif*/ } else { real_len = len; } /*endif*/ if (real_len == 0) return 0; /*endif*/ to_end = p->len + 1 - p->optr; if (p->iptr < p->optr && to_end < real_len) { /* A two step process */ if (buf) { memcpy(buf, p->data + p->optr, to_end); memcpy(buf + to_end, p->data, real_len - to_end); } /*endif*/ } else { /* A one step process */ if (buf) memcpy(buf, p->data + p->optr, real_len); /*endif*/ } /*endif*/ return real_len; } /*- End of function --------------------------------------------------------*/ int queue_read(queue_t *p, uint8_t *buf, int len) { int real_len; int to_end; real_len = queue_contents(p); if (real_len < len) { if (p->flags & QUEUE_READ_ATOMIC) return -1; /*endif*/ } else { real_len = len; } /*endif*/ if (real_len == 0) return 0; /*endif*/ to_end = p->len + 1 - p->optr; if (p->iptr < p->optr && to_end < real_len) { /* A two step process */ if (buf) { memcpy(buf, p->data + p->optr, to_end); memcpy(buf + to_end, p->data, real_len - to_end); } /*endif*/ p->optr += (real_len - p->len + 1); } else { /* A one step process */ if (buf) memcpy(buf, p->data + p->optr, real_len); /*endif*/ p->optr += real_len; if (p->optr > (p->len + 1)) p->optr = 0; /*endif*/ } /*endif*/ return real_len; } /*- End of function --------------------------------------------------------*/ int queue_write(queue_t *p, const uint8_t *buf, int len) { int real_len; int to_end; real_len = queue_free_space(p); if (real_len < len) { if (p->flags & QUEUE_WRITE_ATOMIC) return -1; /*endif*/ } else { real_len = len; } /*endif*/ if (real_len == 0) return 0; /*endif*/ to_end = p->len + 1 - p->iptr; if (p->iptr < p->optr || to_end >= real_len) { /* A one step process */ memcpy(p->data + p->iptr, buf, real_len); p->iptr += real_len; if (p->iptr > (p->len + 1)) p->iptr = 0; /*endif*/ } else { /* A two step process */ memcpy(p->data + p->iptr, buf, to_end); memcpy(p->data, buf + to_end, real_len - to_end); p->iptr += (real_len - p->len + 1); } /*endif*/ return real_len; } /*- End of function --------------------------------------------------------*/ int queue_test_msg(queue_t *p) { uint16_t lenx; if (queue_view(p, (uint8_t *) &lenx, sizeof(uint16_t)) != sizeof(uint16_t)) return -1; /*endif*/ return lenx; } /*- End of function --------------------------------------------------------*/ int queue_read_msg(queue_t *p, uint8_t *buf, int len) { uint16_t lenx; if (queue_read(p, (uint8_t *) &lenx, sizeof(uint16_t)) != sizeof(uint16_t)) return -1; /*endif*/ if (lenx == 0) return 0; /*endif*/ if ((int) lenx > len) { len = queue_read(p, buf, len); /* Discard the rest of the message */ queue_read(p, NULL, lenx - len); return len; } /*endif*/ return queue_read(p, buf, lenx); } /*- End of function --------------------------------------------------------*/ int queue_write_msg(queue_t *p, const uint8_t *buf, int len) { uint16_t lenx; if (queue_free_space(p) < (int) (len + sizeof(uint16_t))) return 0; /*endif*/ lenx = (uint16_t) len; if (queue_write(p, (uint8_t *) &lenx, sizeof(uint16_t)) != sizeof(uint16_t)) return -1; /*endif*/ if (len == 0) return 0; return queue_write(p, buf, len); } /*- End of function --------------------------------------------------------*/ int queue_create(queue_t *p, int len, int flags) { p->iptr = p->optr = 0; p->flags = flags; p->len = len; p->data = malloc(len + 1); if (p->data == NULL) { p->flags = 0; p->len = 0; return -1; } /*endif*/ return 0; } /*- End of function --------------------------------------------------------*/ int queue_delete(queue_t *p) { p->flags = 0; p->iptr = p->optr = 0; p->len = 0; if (p->data) { free(p->data); p->data = NULL; } return 0; } /*- End of function --------------------------------------------------------*/ /*- End of file ------------------------------------------------------------*/