| /* |
| The mediastreamer library aims at providing modular media processing and I/O |
| for linphone, but also for any telephony application. |
| Copyright (C) 2001 Simon MORLAT simon.morlat@linphone.org |
| |
| 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; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| */ |
| |
| #ifdef HAVE_GLIB |
| #include <glib.h> |
| #else |
| #include "glist.h" |
| #endif |
| #include "msbuffer.h" |
| |
| typedef struct _MSFifo |
| { |
| gint r_gran; /*maximum granularity for reading*/ |
| gint w_gran; /*maximum granularity for writing*/ |
| gchar * rd_ptr; /* read pointer on the position where there is something to read on the MSBuffer */ |
| guint32 readsize; |
| gchar * wr_ptr; |
| gchar * prev_wr_ptr; |
| guint32 writesize; /* write pointer on the position where it is possible to write on the MSBuffer */ |
| gchar * begin; /* rd_ptr et wr_ptr must all be >=begin*/ |
| guint32 size; /* the length of the fifo, but this may not be equal to buffer->size*/ |
| guint32 saved_offset; |
| gchar * pre_end; /* the end of the buffer that is copied at the begginning when we wrap around*/ |
| gchar * w_end; /* when a wr ptr is expected to exceed end_offset, |
| it must be wrapped around to go at the beginning of the buffer. This is the end of the buffer*/ |
| gchar * r_end; /* this is the last position written at the end of the fifo. If a read ptr is expected to |
| exceed this pointer, it must be put at the begginning of the buffer */ |
| void *prev_data; /*user data, usually the writing MSFilter*/ |
| void *next_data; /* user data, usually the reading MSFilter */ |
| MSBuffer *buffer; |
| } MSFifo; |
| |
| /* constructor*/ |
| /* r_gran: max granularity for reading (in number of bytes)*/ |
| /* w_gran: max granularity for writing (in number of bytes)*/ |
| /* r_offset: number of bytes that are kept available behind read pointer (for recursive filters)*/ |
| /* w_offset: number of bytes that are kept available behind write pointer (for recursive filters)*/ |
| /* buf is a MSBuffer that should be compatible with the above parameter*/ |
| MSFifo * ms_fifo_new(MSBuffer *buf, gint r_gran, gint w_gran, gint r_offset, gint w_offset); |
| |
| /*does the same that ms_fifo_new(), but also allocate a compatible buffer automatically*/ |
| MSFifo * ms_fifo_new_with_buffer(gint r_gran, gint w_gran, gint r_offset, gint w_offset, gint min_buffer_size); |
| |
| void ms_fifo_destroy( MSFifo *fifo); |
| |
| void ms_fifo_destroy_with_buffer(MSFifo *fifo); |
| |
| /* get data to read */ |
| gint ms_fifo_get_read_ptr(MSFifo *fifo, gint bsize, void **ret_ptr); |
| |
| /* get a buffer to write*/ |
| gint ms_fifo_get_write_ptr(MSFifo *fifo, gint bsize, void **ret_ptr); |
| |
| /* in case the buffer got by ms_fifo_get_write_ptr() could not be filled completely, you must |
| tell it by using this function */ |
| void ms_fifo_update_write_ptr(MSFifo *fifo, gint written); |