char *BufferProtocol::gather(size_t size)
{
if(!input || size > bufsize)
return NULL;
if(size + bufpos > insize) {
if(end)
return NULL;
size_t adjust = outsize - bufpos;
memmove(input, input + bufpos, adjust);
insize = adjust + _pull(input, bufsize - adjust);
bufpos = 0;
if(insize < bufsize)
end = true;
}
if(size + bufpos <= insize) {
char *bp = input + bufpos;
bufpos += size;
return bp;
}
return NULL;
}
int BufferProtocol::_getch(void)
{
if(!input)
return EOF;
if(back) {
back = 0;
return back;
}
if(bufpos == insize) {
if(end)
return EOF;
insize = _pull(input, bufsize);
bufpos = 0;
if(insize == 0)
end = true;
else if(insize < bufsize && !_blocking())
end = true;
if(!insize)
return EOF;
}
return input[bufpos++];
}
size_t BufferProtocol::get(void *address, size_t size)
{
size_t count = 0;
if(!input || !address || !size)
return 0;
char *cp = (char *)address;
while(count < size) {
if(bufpos == insize) {
if(end)
return count;
insize = _pull(input, bufsize);
bufpos = 0;
if(insize == 0)
end = true;
else if(insize < bufsize && !_blocking())
end = true;
if(!insize)
return count;
}
cp[count++] = input[bufpos++];
}
return count;
}
size_t rbs_read(void *ptr, size_t size, size_t nmemb, rbstream_p rbsp)
{
medvdbg("[%s] ptr %p nmemb %lu\n", __FUNCTION__, ptr, nmemb);
RETURN_VAL_IF_FAIL(ptr != NULL, SIZE_ZERO);
RETURN_VAL_IF_FAIL(rbsp != NULL, SIZE_ZERO);
// only size:1 supported
assert(size == 1);
size_t len = size * nmemb;
size_t read = SIZE_ZERO;
while (read < len) {
void *_ptr = (void *) ((uint8_t *) ptr + read);
size_t need = len - read;
size_t offset = rbsp->cur_pos - rbsp->rd_size;
// read data desired
size_t rlen = rb_read_ext(rbsp->rbp, _ptr, need, offset);
read += rlen;
rbsp->cur_pos += rlen; // increase cur_pos
if (read < len) {
// need to read more data
size_t least = len - read;
size_t avail = rb_avail(rbsp->rbp);
if (least > avail) {
// need to dequeue data
if (RBS_OPTION_TEST(rbsp, OPTION_ALLOW_TO_DEQUEUE)) {
offset = rbsp->cur_pos - rbsp->rd_size;
size_t _len = MINIMUM(offset, (least - avail));
size_t _rlen = rb_read(rbsp->rbp, NULL, _len);
assert(_rlen == _len);
rbsp->rd_size += _rlen;
}
}
// pull stream data, then it's available to read more.
if (_pull(rb_avail(rbsp->rbp), least, rbsp) == SIZE_ZERO) {
// pull data failed
break;
}
}
}
medvdbg("[%s] done, read %lu\n", __FUNCTION__, read);
return read;
}
int rbs_seek(rbstream_p rbsp, ssize_t offset, int whence)
{
medvdbg("[%s] offset %ld, whence %d\n", __FUNCTION__, offset, whence);
RETURN_VAL_IF_FAIL(rbsp != NULL, ERROR);
switch (whence) {
case SEEK_SET:
// checking underflow
RETURN_VAL_IF_FAIL(((size_t) offset >= rbsp->rd_size), ERROR);
while ((size_t) offset > rbsp->wr_size) {
size_t least = (size_t) offset - rbsp->wr_size;
size_t wlen;
// pull stream data, then wr_size will be increased
wlen = _pull(rb_avail(rbsp->rbp), least, rbsp);
if ((size_t) offset > rbsp->wr_size) {
// not enough
if (rb_avail(rbsp->rbp) == SIZE_ZERO) {
// ring-buffer is full
RETURN_VAL_IF_FAIL((RBS_OPTION_TEST(rbsp, OPTION_ALLOW_TO_DEQUEUE)), ERROR); // overflow
// dequeue minimal data from ring-buffer
size_t len = rbsp->wr_size - rbsp->rd_size;
least = (size_t) offset - rbsp->wr_size;
len = MINIMUM(len, least);
size_t rlen = rb_read(rbsp->rbp, NULL, len);
assert(rlen == len);
rbsp->rd_size += rlen;
} else {
RETURN_VAL_IF_FAIL((wlen != SIZE_ZERO), ERROR); // EOS
}
// request more data
continue;
}
// got enough data
break;
}
rbsp->cur_pos = (size_t) offset;
break;
}
return OK;
}