/*?Copyright?（C）?2007?Jean-Marc?Valin

???File:?buffer.c
???This?is?a?very?simple?ring?buffer?implementation.?It?is?not?thread-safe
???so?you?need?to?do?your?own?locking.

???Redistribution?and?use?in?source?and?binary?forms?with?or?without
???modification?are?permitted?provided?that?the?following?conditions?are
???met:

???1.?Redistributions?of?source?code?must?retain?the?above?copyright?notice
???this?list?of?conditions?and?the?following?disclaimer.

???2.?Redistributions?in?binary?form?must?reproduce?the?above?copyright
???notice?this?list?of?conditions?and?the?following?disclaimer?in?the
???documentation?and/or?other?materials?provided?with?the?distribution.

???3.?The?name?of?the?author?may?not?be?used?to?endorse?or?promote?products
???derived?from?this?software?without?specific?prior?written?permission.

???THIS?SOFTWARE?IS?PROVIDED?BY?THE?AUTHOR?‘‘AS?IS‘‘?AND?ANY?EXPRESS?OR
???IMPLIED?WARRANTIES?INCLUDING?BUT?NOT?LIMITED?TO?THE?IMPLIED?WARRANTIES
???OF?MERCHANTABILITY?AND?FITNESS?FOR?A?PARTICULAR?PURPOSE?ARE
???DISCLAIMED.?IN?NO?EVENT?SHALL?THE?AUTHOR?BE?LIABLE?FOR?ANY?DIRECT
???INDIRECT?INCIDENTAL?SPECIAL?EXEMPLARY?OR?CONSEQUENTIAL?DAMAGES
???（INCLUDING?BUT?NOT?LIMITED?TO?PROCUREMENT?OF?SUBSTITUTE?GOODS?OR
???SERVICES;?LOSS?OF?USE?DATA?OR?PROFITS;?OR?BUSINESS?INTERRUPTION）
???HOWEVER?CAUSED?AND?ON?ANY?THEORY?OF?LIABILITY?WHETHER?IN?CONTRACT
???STRICT?LIABILITY?OR?TORT?（INCLUDING?NEGLIGENCE?OR?OTHERWISE）?ARISING?IN
???ANY?WAY?OUT?OF?THE?USE?OF?THIS?SOFTWARE?EVEN?IF?ADVISED?OF?THE
???POSSIBILITY?OF?SUCH?DAMAGE.
*/

#ifdef?HAVE_CONFIG_H
#include?“config.h“
#endif


#include?“os_support.h“
#include?“arch.h“
#include?“speex/speex_buffer.h“

struct?SpeexBuffer_?{
???char?*data;
???int???size;
???int???read_ptr;
???int???write_ptr;
???int???available;
};

EXPORT?SpeexBuffer?*speex_buffer_init（int?size）
{
???SpeexBuffer?*st?=?speex_alloc（sizeof（SpeexBuffer））;
???st->data?=?speex_alloc（size）;
???st->size?=?size;
???st->read_ptr?=?0;
???st->write_ptr?=?0;
???st->available?=?0;
???return?st;
}

EXPORT?void?speex_buffer_destroy（SpeexBuffer?*st）
{
???speex_free（st->data）;
???speex_free（st）;
}

EXPORT?int?speex_buffer_write（SpeexBuffer?*st?void?*_data?int?len）
{
???int?end;
???int?end1;
???char?*data?=?_data;
???if?（len?>?st->size）
???{
??????data?+=?len-st->size;
??????len?=?st->size;
???}
???end?=?st->write_ptr?+?len;
???end1?=?end;
???if?（end1?>?st->size）
??????end1?=?st->size;
???SPEEX_COPY（st->data?+?st->write_ptr?data?end1?-?st->write_ptr）;
???if?（end?>?st->size）
???{
??????end?-=?st->size;
??????SPEEX_COPY（st->data?data+end1?-?st->write_ptr?end）;
???}
???st->available?+=?len;
???if?（st->available?>?st->size）
???{
??????st->available?=?st->size;
??????st->read_ptr?=?st->write_ptr;
???}
???st->write_ptr?+=?len;
???if?（st->write_ptr?>?st->size）
??????st->write_ptr?-=?st->size;
???return?len;
}

EXPORT?int?speex_buffer_writezeros（SpeexBuffer?*st?int?len）
{
???/*?This?is?almost?the?same?as?for?speex_buffer_write（）?but?using