int url_lpread(URLContext *s,unsigned char * buf,int size)
{
url_lpbuf_t *lp;
int len=size;
int valid_data_can_read;
unsigned char *tbuf=buf;
if(!s || !s->lpbuf)
return -1;
lp=s->lpbuf;
lp_lock(&lp->mutex);
lp_rprint(AV_LOG_INFO, "url_lpread:buffer=%x,rp=%x,wp=%x,end=%x,lp->valid_data_size=%d,pos=%lld\n",
lp->buffer,lp->rp,lp->wp,lp->buffer_end,lp->valid_data_size,lp->pos);
while(len>0)
{
if(lp->wp>=lp->rp)
valid_data_can_read=lp->wp-lp->rp;
else
valid_data_can_read=lp->buffer_end-lp->rp;
valid_data_can_read=FFMIN(len,valid_data_can_read);
LP_ASSERT(valid_data_can_read>=0);
if(valid_data_can_read==0)
{
int rlen;
lp_unlock(&lp->mutex);
if((len<lp->block_read_size) && (lp->seekflags & LESS_BUFF_DATA))
rlen=url_lpfillbuffer(s,len);
else
rlen=url_lpfillbuffer(s,lp->block_read_size);
if(rlen<=0)
{
lp_unlock(&lp->mutex);
return ((size-len)>0)?(size-len):rlen;
}
lp_lock(&lp->mutex);
}
lp_rprint( AV_LOG_INFO, "url_lpread:buffer=%x,rp=%x,wp=%x,end=%x,tbuf=%x,valid_data_can_read=%x(%d)\n",
lp->buffer,lp->rp,lp->wp,lp->buffer_end,tbuf,valid_data_can_read,valid_data_can_read);
if(valid_data_can_read>0)
{
if(tbuf!=NULL)
{
memcpy(tbuf,lp->rp,valid_data_can_read);
tbuf+=valid_data_can_read;
}
lp->rp+=valid_data_can_read;
if(lp->rp>=lp->buffer_end)
lp->rp=lp->buffer;
len-=valid_data_can_read;
}
LP_ASSERT(lp->rp>=lp->buffer);
LP_ASSERT(lp->rp<lp->buffer_end);
}
lp_unlock(&lp->mutex);
return (size-len);
}
int64_t url_lpseek(URLContext *s, int64_t offset, int whence)
{
int64_t pos_on_read;
url_lpbuf_t *lp;
int valid_data_can_seek_forward;
int valid_data_can_seek_back;
int64_t offset1;
int ret;
if(!s || !s->lpbuf)
return AVERROR(EINVAL);
lp=s->lpbuf;
lp_lock(&lp->mutex);
lp_sprint( AV_LOG_INFO, "url_lpseek:offset=%lld whence=%d,buffer=%x,rp=%x,wp=%x,end=%x,pos=%lld\n",
offset,whence,lp->buffer,lp->rp,lp->wp,lp->buffer_end,lp->pos);
if (whence == AVSEEK_SIZE)
{
int64_t size;
if(!s->prot->url_seek){
lp_unlock(&lp->mutex);
return -1;
}
size = s->prot->url_seek(s, 0, AVSEEK_SIZE);
if(size<0){
if ((size = s->prot->url_seek(s, -1, SEEK_END)) < 0)
{
lp_unlock(&lp->mutex);
return size;
}
size++;
s->prot->url_seek(s,lp->pos, SEEK_SET);
}
lp_sprint(AV_LOG_INFO,"get file size=%lld\n",size);
lp_unlock(&lp->mutex);
return size;
}
else if(whence == SEEK_END)
{
if(!s->prot->url_seek){
lp_unlock(&lp->mutex);
return -1;
}
if ((offset1=s->prot->url_seek(s, offset, SEEK_END)) < 0)
{
lp_unlock(&lp->mutex);
return offset1;
}
lp->rp=lp->buffer;
lp->wp=lp->buffer;
lp->valid_data_size=0;
lp->pos=offset1;
lp_unlock(&lp->mutex);
return offset1;
}
if (whence != SEEK_CUR && whence != SEEK_SET)
{
lp_unlock(&lp->mutex);
return AVERROR(EINVAL);
}
if(lp->wp>=lp->rp)
valid_data_can_seek_forward=lp->wp-lp->rp;
else
valid_data_can_seek_forward=lp->buffer_size-(lp->rp-lp->wp);
pos_on_read = lp->pos-valid_data_can_seek_forward;
if(whence == SEEK_CUR)
{
offset1 = pos_on_read;
if (offset == 0)
{
lp_unlock(&lp->mutex);
return offset1;
}
offset += offset1;
}
valid_data_can_seek_back=FFMIN(lp->valid_data_size-valid_data_can_seek_forward,
lp->buffer_size-valid_data_can_seek_forward-64);
if(valid_data_can_seek_back<0)
valid_data_can_seek_back=0;
offset1 = offset - pos_on_read;/*seek forword or back*/
lp_sprint( AV_LOG_INFO, "url_lpseek:pos_on_read=%lld,can seek forwart=%d,can seek bacd=%d,offset1=%lld\n",
pos_on_read,valid_data_can_seek_forward,valid_data_can_seek_back,offset1);
if(offset1>=0 && offset1<=valid_data_can_seek_forward)
{/*seek forward in lp buffer*/
lp_sprint( AV_LOG_INFO, "url_lpseek:buffer seek forword offset=%lld offset1=%lld whence=%d\n",offset,offset1,whence);
lp->rp+=(int)offset1;
if(lp->rp>=lp->buffer_end)
lp->rp-=lp->buffer_size;
}else if(offset1<0 && (-offset1)<=valid_data_can_seek_back)
{/*seek back in lp buffer*/
lp_sprint( AV_LOG_INFO, "url_lpseek:buffer seek back offset=%lld offset1=%lld whence=%d,(int)offset1=%d\n",offset,offset1,whence,(int)offset1);
lp->rp+=(int)offset1;
if(lp->rp<lp->buffer)
lp->rp+=lp->buffer_size;
}else if(offset1>0 && (s->is_streamed || s->is_slowmedia) &&
(offset1<lp->buffer_size-lp->block_read_size) &&
(lp->file_size<=0 || (lp->file_size>0 && offset1<lp->file_size/2)))/*if offset1>filesize/2,thendo first seek end,don't buffer*/
{/*seek to buffer end,but buffer is not full,do read seek*/
int read_offset,ret;
lp_sprint( AV_LOG_INFO, "url_lpseek:buffer read seek forward offset=%lld offset1=%lld whence=%d\n",offset,offset1,whence);
lp->rp+=valid_data_can_seek_forward;
if(lp->rp>=lp->buffer_end)
lp->rp-=lp->buffer_size;
lp_unlock(&lp->mutex);
read_offset=offset1-valid_data_can_seek_forward;
while(read_offset>0){
ret=url_lpread(s,NULL,read_offset);/*do read seek*/
if(ret>0)
read_offset-=ret;
else if(ret!=AVERROR(EAGAIN)){
offset=ret;/*get error,exit now*/
break;
}
}
lp_lock(&lp->mutex);
}else
{/*not support in buffer seek,do low level seek now*/
lp_sprint( AV_LOG_INFO, "url_lpseek:buffer lowlevel seek offset=%lld offset1=%lld whence=%d\n",offset,offset1,whence);
if(!s->prot->url_seek){
lp_unlock(&lp->mutex);
return -1;
}
if(lp->cache_enable && offset<lp->file_size){
/*if cache enable not need to seek here,seek on cache missed*/
;/*do't do seek here*/
}else if ((offset1=s->prot->url_seek(s, offset, SEEK_SET)) < 0)
{
lp->valid_data_size=0;/*seek failed clear all old datas*/
offset1 = s->prot->url_seek(s, lp->pos, SEEK_SET);/*clear the lowlevel errors*/
lp_unlock(&lp->mutex);
return offset1;
}
lp->rp=lp->buffer;
lp->wp=lp->buffer;
lp->valid_data_size=0;
lp->pos=offset;
}
lp_sprint( AV_LOG_INFO, "url_lpseekend:offset=%lld whence=%d,buffer=%x,rp=%x,wp=%x,end=%x,pos=%lld\n",
offset,whence,lp->buffer,lp->rp,lp->wp,lp->buffer_end,lp->pos);
LP_ASSERT(lp->rp>=lp->buffer);
LP_ASSERT(lp->rp<lp->buffer_end);
lp_unlock(&lp->mutex);
return offset;
}